US20070135826A1 - Method and apparatus for delivering an implant without bias to a left atrial appendage - Google Patents

Abstract

A system and method for delivering an implant includes an implant, an actuation shaft, and a concentrically attachable disconnect mount. A distal guide tube is sometimes also provided. A proximal guide tube is also sometimes provided. The implantable device has a proximal, a distal end, and a plurality of supports. The implantable device is moveable between a collapsed and an expanded configuration. The distal guide tube, when provided, is at the distal end of the supports and extends toward the proximal end of the implantable device. The actuation shaft extends through the proximal end of the implantable device and is removeably engageable with the distal guide tube, or the distal end of the device when the distal guide tube is not provided. The disconnect mount is releasably engageable with the proximal end of the implantable device. The disconnect mount is concentrically attachable to the proximal end of the implantable device as well. The implantable device is self-expandable, and is collapsed by engaging the actuation shaft with the distal guide tube while applying a relatively proximal force to the proximal end of the implant with the disconnect mount.

Description

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS
• This application claims the benefit of priority from U.S. Provisional No. 60/741,111, filed Dec. 1, 2005, which is incorporated by reference, herein.
BACKGROUND
• Embolic stroke is the nation's third leading killer for adults, and is a major cause of disability. There are over 700,000 strokes per year in the United States alone. Of these, roughly 100,000 are hemorrhagic, and 600,000 are ischemic (either due to vessel narrowing or to embolism). The most common cause of embolic stroke emanating from the heart is thrombus formation due to atrial fibrillation. Approximately 80,000 strokes per year are attributable to atrial fibrillation. Atrial fibrillation is an arrhythmia of the heart that results in a rapid and chaotic heartbeat that produces lower cardiac output and irregular and turbulent blood flow in the vascular system. There are over five million people worldwide with atrial fibrillation, with about four hundred thousand new cases reported each year. Atrial fibrillation is associated with a 500 percent greater risk of stroke due to the condition. A patient with atrial fibrillation typically has a significantly decreased quality of life due, in part, to the fear of a stroke, and the pharmaceutical regimen necessary to reduce that risk.
• For patients who develop atrial thrombus from atrial fibrillation, the clot normally occurs in the left atrial appendage (LAA) of the heart. The LAA is a cavity which looks like a small finger or windsock and which is connected to the lateral wall of the left atrium between the mitral valve and the root of the left pulmonary vein. The LAA normally contracts with the rest of the left atrium during a normal heart cycle, thus keeping blood from becoming stagnant therein, but often fails to contract with any vigor in patients experiencing atrial fibrillation due to the discoordinate electrical signals associated with atrial fibrillation. As a result, thrombus formation is predisposed to form in the stagnant blood within the LAA.
• Blackshear and Odell have reported that of the 1288 patients with non-rheumatic atrial fibrillation involved in their study, 221 (17%) had thrombus detected in the left atrium of the heart. Blackshear J L, Odell J A., Appendage Obliteration to Reduce Stroke in Cardiac Surgical Patients With Atrial Fibrillation. Ann Thorac. Surg., 1996.61(2):755-9. Of the patients with atrial thrombus, 201 (91%) had the atrial thrombus located within the left atrial appendage. The foregoing suggests that the elimination or containment of thrombus formed within the LAA of patients with atrial fibrillation would significantly reduce the incidence of stroke in those patients.
• Pharmacological therapies for stroke prevention such as oral or systemic administration of warfarin or the like have been inadequate due to serious side effects of the medications and lack of patient compliance in taking the medication. Invasive surgical or thorascopic techniques have been used to obliterate the LAA, however, many patients are not suitable candidates for such surgical procedures due to a compromised condition or having previously undergone cardiac surgery. In addition, the perceived risks of even a thorascopic surgical procedure often outweigh the potential benefits. See Blackshear and Odell, above. See also Lindsay B D., Obliteration of the Left Atrial Appendage: A Concept Worth Testing, Ann Thorac. Surg., 1996.61(2):515.
• During surgical procedures, such as mitral valve repair, thrombus in the left atrial appendage may leave the LAA and enter the blood stream of a patient. The thrombus in the blood stream of the patient can cause embolic stroke. There are known techniques for closing off the LAA so that thrombus cannot enter the patient's blood stream. For example, surgeons have used staples or sutures to close the orifice of the LAA, such that the closed off LAA surrounds the thrombus. Unfortunately, using staples or sutures to close off the LAA may not completely close the orifice of the LAA. Thus, thrombus may leave the LAA and enter the patient's blood stream, even though the LAA is closed with staples or sutures. Additionally, closing the orifice of the LAA by using staples or sutures may result in discontinuities, such as folds or creases, in the endocardial surface facing the left atrium. Unfortunately, blood clots may form in these discontinuities and can enter the patient's blood stream, thereby causing health problems. Moreover, it is difficult to place sutures at the orifice of the LAA and may result in a residual appendage. For example, an epicardial approach to ligate sutures can result in a residual appendage. Similarly, thrombus may form in the residual appendage and enter the patient's blood stream causing health problems.
• Despite the various efforts in the prior art, there remains a need for a minimally invasive method and associated devices for reducing the risk of thrombus formation in the left atrial appendage. Various implantable devices and methods of delivery have been previously described. However, some delivery devices can have limited flexibility and can provide off-axis loading that creates moment arms and bending bias. Moment arms and bending bias can cause the implant to “jump” or move within the left atrial appendage when it is detached from the implant delivery system. Therefore, it would be advantageous for a left atrial appendage implantation to system to avoid moment arms and bending bias such that when the implant is released it remains in the position it had when coupled to the delivery system.
SUMMARY OF THE INVENTION
• There is provided in accordance with one embodiment of the present invention a system and method for minimizing, reducing, substantially eliminating, and/or eliminating implantation bias during delivery of an implant. The system includes an implant with a distal guide tube, an actuation shaft, and a concentrically attachable disconnect mount. In one embodiment the implant is configured to contain emboli with a left atrial appendage of a heart of a patient. The implantable device has a proximal and distal end with a plurality of supports and is moveable between a collapsed and an expanded configuration. The distal guide tube at the distal end of the supports extends toward the proximal end of the implant. The actuation shaft extends through the proximal end of the implantable device and is removeably engageable with the distal guide tube. The disconnect mount is releasably engageable with the proximal end of the implant and is concentrically attachable to the proximal end of the implant. In one embodiment, the implant is self-expandable. In another embodiment, the implant is collapsed by engaging the actuation shaft with the distal guide tube while applying a relatively proximal force to the proximal end of the implant with the disconnect mount.
• In one embodiment of the present invention, an implant delivery system includes an implantable device, a proximal guide tube, and a distal guide tube. The implantable device has a plurality of supports extending between a proximal end and a distal end. The supports are moveable between a collapsed configuration and an expanded configuration.
• In one embodiment, the proximal guide tube is located at the proximal end of the supports and extends toward the distal end of the device. The distal guide tube is located at the distal end of the supports and extends toward the proximal end of the device. The proximal and distal guide tubes are telescoping and become further engaged as the supports move from the collapsed to the expanded configuration.
• In another embodiment of the present invention, an implant delivery system includes an implantable device, an actuation shaft, and a disconnect mount. In some embodiments, the implant delivery system further comprises a distal guide tube. The implantable device has a proximal end, a distal end, and a plurality of supports extending therebetween. The implantable device is moveable between a collapsed configuration and an expanded configuration.
• In one embodiment, the distal guide tube, when provided, is located at the distal end of the supports and extends toward the proximal end of the device. The actuation shaft is extendable through the proximal end of the implantable device and is removeably engageable with the distal guide tube. The disconnect mount is releasably engageable with the proximal end of the implantable device. The disconnect mount is concentrically attachable to the proximal end of the implantable device.
• In some embodiments, the implantable device is self-expanding. In other embodiments, the implantable device is collapsed by engaging the actuation shaft with the distal guide tube while applying a relatively proximal force to the proximal end of the implantable device with the disconnect mount.
• In yet another embodiment of the present invention, a method of actuating an implantable device with a concentric force includes providing an implantable device, applying a concentric force, and applying a distal force. The implantable device has a proximal end, a distal end, and a plurality of supports extending therebetween. The implantable device is configured to expand from a reduced-diameter configuration to an expanded-diameter configuration. In one embodiment, the concentric force is applied to the proximal end. In other embodiments, the distal force is applied to the distal end.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a view of a heart and its left atrial appendage;
• FIG. 2 is a block diagram representing a simplified implant delivery system in accordance with one embodiment of the present invention;
• FIG. 2A is a schematic view of one embodiment of the delivery system ofFIG. 2;
• FIG. 3A is a side elevational view of the distal end of an embodiment of an implant delivery system;
• FIG. 3B is a side elevational view of the distal end of another embodiment of an implant delivery system;
• FIG. 4A is a side elevational view of the distal end of the implant delivery system shown inFIG. 3A with a radially-reduced implant;
• FIG. 4B is a side elevational view of the distal end of the implant delivery system shown inFIG. 4A with a radially-expanded implant;
• FIG. 4C is a side elevational view of the distal end of an implant delivery system shown inFIG. 4B with a released radially-expanded implant;
• FIG. 5A is a side elevational view of the distal end of the implant delivery system shown inFIG. 3B with a radially-reduced implant;
• FIG. 5B is a side elevational view of the distal end of the implant delivery system shown inFIG. 5A with a radially-expanded implant;
• FIG. 5C is a side elevational view of the distal end of an implant delivery system shown inFIG. 5B with a released radially-expanded implant;
• FIG. 6 is a schematic view of a deployment system delivering an implantable containment device to the left atrial appendage;
• FIG. 7 is a perspective view of a support structure for a containment device in accordance with a further embodiment of the present invention;
• FIG. 7A is a side elevational view of the device ofFIG. 7;
• FIG. 7B is an end view taken along theline7B-7B ofFIG. 7A;
• FIGS. 8 and 9 are side elevational schematic representations of partial and complete barrier layers of the containment device ofFIG. 7;
• FIG. 10 is a side elevational schematic view of an alternate containment device in accordance with another embodiment of the present invention;
• FIG. 11 is a schematic view of a deployment system in accordance with one embodiment of the present invention;
• FIG. 11A is an enlarged detail view of the deployment system ofFIG. 11, showing a releasable lock in an engaged configuration;
• FIG. 11B is an enlarged detail view as inFIG. 11A, with a core axially retracted to release the implant;
• FIG. 12A is a perspective view of a flexible guide tube for use in the configurations ofFIG. 11 and/orFIG. 14;
• FIG. 12B is a schematic view of a flexible guide tube for use in embodiments of the configurations ofFIG. 11;
• FIG. 13A is a schematic view of an implant with concentric slideable guide tubes in a radially-reduced state in accordance with one embodiment of the present invention;
• FIG. 13B is a schematic view of the implant with concentric slideable guide tubes ofFIG. 13A in a radially-expanded state;
• FIG. 14 is a schematic view of an alternate deployment system in accordance with one embodiment of the present invention;
• FIG. 15A illustrates a schematic cross-sectional view through the distal end of a retrieval catheter having a containment device removably connected thereto in accordance with one embodiment of the present invention;
• FIG. 15B is a perspective view of an embodiment of a single layer petal configuration of a portion of a retrieval catheter in accordance with one embodiment of the present invention;
• FIG. 15C is a schematic cross-sectional view of the system illustrated inFIG. 15A, with the containment device axially elongated and radially reduced;
• FIG. 15D is a cross-sectional schematic view as inFIG. 15C, with the containment device drawn part way into the retrieval catheter;
• FIG. 15E is a schematic view as inFIG. 15D, with the containment device and delivery catheter drawn into a transseptal sheath;
• FIG. 16A is a schematic cross-sectional view of a distal portion of an adjustable implant deployment system, in accordance with another embodiment;
• FIG. 16B is a schematic partial sectional view of an assembly incorporating quick-disconnect functionality of the assembly inFIG. 16A;
• FIGS.17A-C are schematic cross-sectional views of an implant release and recapture mechanism having an internal lock tube, in accordance with another embodiment;
• FIGS.18A-C are schematic cross-sectional views of another implant release and recapture mechanism having an internal lock tube, in accordance with another embodiment;
• FIGS.19A-C are schematic cross-sectional views of an implant release and recapture mechanism of an implant deployment system having an external lock tube, in accordance with another embodiment;
• FIGS.20A-C are schematic cross-sectional views of another implant release and recapture mechanism having an external lock tube, in accordance with another embodiment;
• FIGS.21A-C are schematic cross-sectional views of an embodiment of an implant release and recapture mechanism having a threaded portion of an implant actuation shaft, in accordance with another embodiment;
• FIGS.21D-E are cross-sectional views of another embodiment of an implant release mechanism;
• FIG. 21F is a cross-section view of another embodiment of an implant release mechanism;
• FIG. 22 is a schematic view of a delivery system in accordance with one embodiment of the present invention;
• FIG. 22A is a cross-sectional view of an implant delivery system as shown inFIG. 22, taken alongline22A-22A;
• FIG. 23 is a partial cross-sectional view of the distal end of a deployment system constructed in accordance with one embodiment of the present invention;
• FIG. 24 is a partial cross-sectional view of an axially moveable core used in the system ofFIG. 22;
• FIG. 24A is a cross-sectional view of the axially moveable core ofFIG. 24 taken alongline24A-24A;
• FIG. 25 is a schematic of an embodiment of a flexible catheter system constructed in accordance with one embodiment of the present invention;
• FIG. 25A is a close up of an embodiment of a puzzle lock profile constructed in accordance with one embodiment of the present invention;
• FIG. 25B is a perspective view of a tube with the puzzle lock profile ofFIG. 25A; and
• FIG. 25C is a close up of the puzzle lock profile ofFIG. 25B.
DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS
• FIG. 1 illustrates a sectional view of aheart5 and its left atrial appendage (LAA)10. Animplant100 is provided at least partially within theLAA10. The terms “implant”, “occlusion device” or “containment device” are broad terms intended to have their ordinary meaning. In addition, these terms are intended to refer to devices that are inserted into the body. Such devices may include a membrane, barrier and/or cover, or may omit these portions. Embodiments of the invention may also be used to treat other bodily openings, lumen and cavities, besides theLAA10. For example, in some embodiments, the methods, devices and systems described herein are used to treat any heart opening or defect, such as a patent foramen ovale (PFO), an atrial septal defect (ASD), a ventricular septal defect (VSD), a patent ductus arteriosus (PDA), an aneurysm and/or an aortico-pulmonary window.
• In various embodiments, animplant100 can be delivered in a number of ways, e.g., using conventional transthoracic surgical, minimally invasive, or port access approaches. Delivery can be made or done in conjunction with surgical procedures as well. In one embodiment, theimplant100 is used in conjunction with various surgical heart procedures related to the heart (e.g., mitral valve repair) or surgical procedures in the region surrounding the heart. The delivery system can be used to locate and deploy theimplant100 in order to prevent the passage of embolic material from theLAA10, such that thrombus remains contained in theLAA10. Thrombus remains contained in theLAA100 because theimplant100 inhibits thrombus within theLAA10 from passing through the orifice of theLAA10 and into the patient's blood stream. Additionally, the deployedimplant100 located in theLAA10 can provide a smooth, non-thrombogenic surface facing the left atrium. In one embodiment, the smooth, non-thrombogenic surface facing the left atrium will not promote blood clots to form proximate to theLAA10. Access to the heart may be provided by surgical procedures in order to deploy theimplant100 in theLAA10. That is, theimplant100 can be deployed as an adjunct to surgical procedures. Various methods for accessing theLAA10 and delivering animplant100 to theLAA10 are disclosed in U.S. application Ser. No. 11/003,696, filed Dec. 3, 2004, published as U.S. Publication No. 2005-0177182 A1, which is incorporated by reference herein.
• A. Implant Delivery System
• FIG. 2 illustrates a block diagram of animplant delivery system50. Theimplant delivery system50 includes animplant100, an implant release and recapturemechanism200, acatheter system300 and adeployment handle400. In some embodiments, the implant release and recapturemechanism200 is the distal portion of thecatheter system300 and thedeployment handle400 is the proximal portion of thecatheter system300. The implant release and recapturemechanism200 generally couples theimplant100 to thecatheter system300. The deployment handle400 generally provides all the user controls and actuators of theimplant delivery system50.
• FIG. 2A illustrates one embodiment of theimplant delivery system50 ofFIG. 2. Theimplant delivery system50 includes an implant release and recapturemechanism200 that is flexible and without bias. In this manner, when theimplant100 is released from thedelivery system50, theimplant100 maintains the position and orientation it had when coupled to thedelivery system50, and does not spring, jump, or move, as described above.
• FIG. 3A illustrates one example of an implant100 (schematically shown) coupled to acatheter system300 with an implant release and recapturemechanism200. In the illustrated embodiment, the implant release and recapturemechanism200 is relatively stiff and extends_over arelease mechanism length201. The implant release and recapturemechanism200 includes animplant actuation shaft334 and atether line210. Theimplant100 is generally self-expandable and is held in a reduced-diameter configuration by pushing against the distal end of the inside of theimplant100 while pulling on the implant's proximal end. For example, theimplant actuation shaft334 pushes against the implant distal end while thetether line210 is held in tension to maintain theimplant100 in a reduced-diameter configuration. To expand the implant, tension on thetether line210 is reduced and/or theimplant actuation shaft334 is moved proximally.
• However, theimplant actuation shaft334 andtether line210 can have limited flexibility and can provide off-axis loading that creates moment arms and bending bias. Deployment of theimplant100 in the confines of the heart5 (not illustrated here) may require bending of the implant release and recapturemechanism200, acatheter system300, but stiffness along arelease mechanism length201 reduces flexibility and creates moment arm and bending bias.
• FIG. 3B illustrates another embodiment of animplant100 coupled to acatheter system300 with an implant release and recapturemechanism200. In the illustrated embodiment, the implant release and recapturemechanism200 is relatively stiff and extends over arelease mechanism length202. The implant release and recapturemechanism200 and thecatheter system300 are flexible and can be manipulated in order to access theLAA10. When device stiffness or rigidity along arelease mechanism length202 is shorter than arelease mechanism length201, the device has increased flexibility and shorter moment arms, resulting in less bending bias.
• FIGS.4A-C illustrate the implant release sequence of theimplant100 with the implant release and recapturemechanism200 ofFIG. 3A.FIG. 4A illustrates an example of animplant100, an implant release and recapturemechanism200, and acatheter system300 where the implant release and recapturemechanism200 is relatively stiff and extends over arelease mechanism length201.FIG. 4B illustrates acatheter system300 using animplant actuation shaft334 and atether line210, which are used as components within the implant release and recapturemechanism200. When theimplant100 is radially expanded theimplant100 can move axially toward the distal end of theimplant100, thereby exposing theimplant actuation shaft334 andtether line210. The off-axis tension in thetether line210 can create moment arms and bending bias which can cause theimplant100 to “jump,” move, rotate, etc., within theLAA10 when theimplant100 is detached from the implant delivery system, as is illustrated inFIG. 4C.
• FIGS.5A-C illustrate the implant release sequence of theimplant100 with the implant release and recapturemechanism200 ofFIG. 3B.FIG. 5A illustrates an example of animplant100, an implant release and recapturemechanism200, acatheter system300 where the implant release and recapturemechanism200 is relatively stiff and extends over arelease mechanism length202.Length202 is shorter thanlength201 ofFIG. 4A.FIG. 5B illustrates the expansion of theimplant100 with shorter moment arms and less bending bias than the systems illustrated in FIGS.4A-C. As illustrated inFIG. 5C, the release of theimplant100 from thecatheter system300 results in smaller moment arms and less bending bias than in FIGS.4A-C. The detachment of theimplant100 results in less of a “jump” and reduced movement and/or rotation within theLAA10.
• 1. Implant
• FIG. 6 illustrates animplant100 placed inside aLAA10 of aheart5, an implant release and recapturemechanism200, and acatheter system300. In one embodiment, theimplant100 is a transluminally delivered device designed to occlude or contain particles within theLAA10 and prevent thrombus from forming in, and emboli from originating from, theLAA10. Thedelivery system50 may be used to deliver theimplant100 to occlude or block theLAA10 in a patient with atrial fibrillation. Thedelivery system50 may be compatible for use with a transseptai sheath (not shown). Thedelivery system50 andimplant100 may be selected to allow theimplant100 to be positioned, repositioned, and retrieved from theLAA10 if necessary.
• Theimplant100 often includes aframe101 and a membrane (not shown) on aproximal face104 of the implant, such as described below. In an embodiment, theframe101 is constructed of self-expanding nitinol supports. The membrane may be constructed of a fabric covering, such as one made of ePTFE, or an ePTFE/PE laminate. To attach the membrane to theframe101, a PE mesh preferably is placed against the supports, with one sheet of ePTFE preferably placed over the PE mesh and another sheet of ePTFE preferably placed on an opposite side of the supports. The membrane may be heated on both sides causing the PE to melt into both sheets of ePTFE, thereby surrounding a portion of theframe101. The nitinol supports allow theimplant100 to self-expand in theappendage10, covering the orifice with the laminated fabric. The porous ePTFE/PE lamination facilitates rapid endothelialization and healing.
• In one embodiment, theimplant100 is expandable and collapsible. Theimplant100 can include anchors that extend from the implant'sframe101 when theimplant100 is expanded, as described below. Theimplant100 is available in a range of sizes to accommodate the anatomy of a patient'sLAA10. When used in theLAA10, theimplant100 may have an expanded diameter within the range of from about 1 cm to about 5 cm, and, in one embodiment, about 3 cm. The overall axial length of theimplant10 from itsdistal end102 to itsproximal end104 is within the range of from about 1.5 cm to about 4 cm and, in one embodiment, about 2.5 cm.
• In one embodiment, thedelivery system50 includes atransseptal sheath520. Aradiopaque marker521 is located near the distal end of thetransseptal sheath520.
• FIGS. 7, 7A and7B illustrate animplant100 in accordance with another embodiment of the present invention. Theimplant100 includes adistal end102, aproximal end104, and a longitudinal axis extending therebetween. A plurality ofsupports106 extend between adistal hub108 and aproximal hub110. At least two or threesupports106 are provided, and in other embodiments, at least about tensupports106 are provided. In one embodiment, sixteensupports106 are provided. However, the precise number ofsupports106 can be modified, depending upon the desired physical properties of theimplant100 as will be apparent to those of skill in the art in view of the disclosure herein, without departing from the present invention.
• In an embodiment, eachsupport106 includes adistal spoke portion112, aproximal spoke portion114, and an apex116. Each of thedistal spoke portion112, the proximal spokeportion114, and the apex116 may be a region on anintegral support106, such as a continuous rib or frame member which extends in a generally curved configuration as illustrated with a concavity facing towards the longitudinal axis of theimplant100. Thus, no distinct point or hinge atapex116 is necessarily provided.
• At least some of thesupports106, and, preferably, eachsupport106, is provided with one or two ormore anchors118 orbarbs118. In the illustrated configuration, theimplant100 is in its enlarged orientation, such as for occluding a leftatrial appendage10 or other body cavity or lumen. In this orientation, each of thebarbs118 projects generally radially outwardly from the longitudinal axis, and is inclined in the proximal direction. One or more barbs may also be inclined distally, as is discussed elsewhere herein. In an embodiment where thebarbs118 andcorresponding support106 are cut from a single ribbon, sheet or tube stock, thebarb118 will incline radially outwardly at approximately a tangent to the curve formed by thesupport106.
• The illustratedanchor118 is in the form of a barb, with at least one on eachsupport106 for extending into tissue at or near the opening of theLAA10. Depending upon the embodiment, two or threebarbs118 may alternatively be desired on eachsupport106. In thesingle barb118 embodiment ofFIG. 7, eachbarb118 is inclined in a proximal direction. This is to inhibit proximal migration of the implant out of the leftatrial appendage10. In this context, distal refers to the direction into the leftatrial appendage10, and proximal refers to the direction from the leftatrial appendage10 into theheart5.
• Alternatively, one ormore barbs118 may face distally, to inhibit distal migration of theimplant100 deeper into theLAA10. Thus, theimplant100 may be provided with at least one proximally facingbarb118 and at least one distally facingbarb118. For example, in an embodiment of the type illustrated inFIG. 10, discussed below, a proximal plurality ofbarbs118 may be inclined in a first direction, and a distal plurality ofbarbs118 may be inclined in a second direction, to anchor theimplant100 against both proximal and distal migration.
• Theimplant100 constructed from the frame illustrated inFIG. 7 may be constructed in any of a variety of ways, as will become apparent to those of skill in the art in view of the disclosure herein. In one method, theimplant100 is constructed by laser cutting a piece of tube stock to provide a plurality of axially extending slots in-betweenadjacent supports106. Similarly, eachbarb118 can be laser cut from thecorresponding support106 or space in-betweenadjacent supports106. The generally axially extending slots which separateadjacent supports106 end a sufficient distance from each of theproximal end104 anddistal end102 to leave aproximal hub110 and adistal hub108 to which each of thesupports106 will attach. In this manner, an integral cage structure may be formed. Alternatively, each of the components of the cage structure may be separately formed and attached together such as through soldering, brazing, heat bonding, adhesives, and other fastening techniques which are known in the art.
• A further method of manufacturing theimplant100 is to laser cut a slot pattern on a flat sheet of appropriate material, such as a flexible metal or polymer. Thesupports106 may comprise a metal such as stainless steel, nitinol, Elgiloy, or others which can be determined through routine experimentation by those of skill in the art. Wires having a circular or rectangular cross-section may be utilized depending upon the manufacturing technique. In one embodiment, rectangular cross section spokes are cut such as by known laser cutting techniques from tube stock, a portion of which forms aproximal hub110 or adistal hub108. The flat sheet may thereafter be rolled about an axis and opposing edges bonded together to form a tubular structure.
• Theapex portion116 which carries thebarb118 may be advanced from a low profile orientation in which each of thesupports106 extend generally parallel to the longitudinal axis, to an implanted orientation as illustrated, in which the apex116 and thebarb118 are positioned radially outwardly from the longitudinal axis. Thesupport106 may be biased towards the enlarged orientation, or may be advanced to the enlarged orientation under positive force following positioning within the tubular anatomical structure, in any of a variety of manners.
• Referring toFIGS. 8 and 9, theimplant100 may be provided with abarrier120 such as a mesh or fabric. Thebarrier120 may comprise any of a variety of materials which facilitate cellular in-growth, such as ePTFE. The suitability of alternate materials forbarrier120 can be determined through routine experimentation by those of skill in the art. Thebarrier120 may be provided on either one or both axially facing sides of theimplant100. In one embodiment, thebarrier120 comprises two layers, with one layer on each side of a cage formed by a plurality ofsupports106. The two layers may be bonded to each other around thesupports106 in any of a variety of ways, such as by heat bonding with or without an intermediate bonding layer such as polyethylene or FEP, adhesives, sutures, and other techniques which will be apparent to those of skill in the art in view of the disclosure herein. In an embodiment, thebarrier120 has a thickness of no more than about 0.003″ and a porosity within the range of from about 5 μm to about 60 μm.
• Barrier120 may be provided on only one hemisphere,proximal face122, or may be carried by theentire implant100 fromproximal end104 todistal end102. The barrier may be secured to the radially inwardly facing surface of thesupports106, as illustrated inFIG. 9, or may be provided on the radially outwardly facing surfaces ofsupports106, or both.
• A further embodiment of theimplant100 is illustrated inFIG. 10, in which the apex116 is elongated in an axial direction to provide additional contact area between theimplant100 and the wall of the tubular structure. In this embodiment, one or two or three ormore anchors118 may be provided on eachsupport106, depending upon the desired clinical performance. Theimplant100 illustrated inFIG. 10 may also be provided with any of a variety of other features discussed herein, such as a partial orcomplete barrier120. In addition, theimplant100 illustrated inFIG. 10 may be enlarged using any of the techniques disclosed elsewhere herein.
• FIG. 11 illustrates another embodiment of the present invention. Theimplant100 may be in the form of any of those described previously herein, as modified below. In general, theimplant100 is movable from a reduced crossing profile to an enlarged crossing profile. Theimplant100 is generally introduced into the body in its reduced crossing profile, and when positioned at the desired deployment location, theimplant100 is expanded to its enlarged crossing profile. When expanded, theimplant100 obstructs or filters the flow of desired particles, emboli, blood, etc., or performs other functions while positioned therein.
• Theimplant100 may be biased in the direction of the enlarged crossing profile, may be neutrally biased, or may be biased in the direction of the reduced crossing profile. Any modifications to the device and deployment system to accommodate these various aspects of theimplant100 may be readily accomplished by those of skill in the art in view of the disclosure herein.
• Theimplant100 is a detachable component of an adjustableimplant delivery system50. The implant deliversystem50 generally includes acatheter302 for inserting in implant into a patient's vasculature, advancing it percutaneously through the vasculature, positioning it at a desire deployment location, and deploying theimplant100 at the deployment location, such as within a body cavity or lumen, as discussed above. Thecatheter302 generally includes an elongate flexibletubular body306 that extends between aproximal end308 and adistal end310. The catheter body has a sufficient length and diameter to permit percutaneous entry into the vascular system and transluminal advancement through the vascular system to the desired deployment site.
• For example, in an embodiment intended for access at the femoral vein and deployment within the leftatrial appendage50, thecatheter302 has a length within the range of from about 50 cm to about 150 cm, and a diameter of generally no more than about 15 French. Further dimensions and physical characteristics of catheters for navigation to particular sites within the body are well understood in the art and will not be further described herein.
• Thetubular body306 is further provided with ahandle402 generally on theproximal end308 of thecatheter302. Thehandle402 permits manipulation of the various aspects of theimplant delivery system50, as will be discussed below. Handle402 may be manufactured in any of a variety of ways, typically by injection molding or otherwise forming a handpiece for single-hand operation, using materials and construction techniques well known in the medical device arts.
• In the illustrated embodiment, thedistal end102 of theimplant100 is provided with animplant plug124. Theimplant plug124 may be integral with thedistal end102 of the implant or it may be a separate, attachable piece.Implant plug124 provides a stoppingsurface126 for contacting an axiallymovable core304 or other such similar structure as described herein. Thecore304 extends axially throughout the length of thecatheter body302, and is attached at its proximal end to acore control404 on thehandle402. In some embodiments, the axially movable core is referred to as a drive shaft or an implant actuation shaft. In one embodiment, theimplant plug124 comprises an atraumatic tip, such that contact between the atraumatic tip and the inside surface of theLAA10 does not cause significant damage to theLAA10.
• Thecore304 may comprise any of a variety of structures which has sufficient lateral flexibility to permit navigation of the vascular system, and sufficient axial column strength to enable reduction of theimplant100 to its reduced crossing profile. Any of a variety of structures such as hypotube, solid core wire, “bottomed out” coil spring structures, or combinations thereof may be used, depending upon the desired performance of the finished device. In one embodiment, thecore304 comprises stainless steel tubing.
• The distal end ofcore304 is positioned within a recess, cavity orlumen132 defined by a proximally extendingdistal guide tube130. In the illustrated embodiment, thedistal guide tube130 is a section of tubing such as metal hypotube, which is attached at thedistal end102 of the implant and extends proximally within theimplant100. In some embodiments thedistal guide tube130 includes adistal end102 of the implant, animplant plug124, and/or a stoppingsurface126 as described herein. Thedistal guide tube130 preferably extends a sufficient distance in the proximal direction to inhibit buckling or prolapse of thecore304 when distal pressure is applied to thecore control404 to reduce the profile of theimplant100. However, theguide tube130 should not extend proximally a sufficient distance to interfere with the opening of theimplant100.
• As will be appreciated by reference toFIG. 11, theguide tube130 may operate as a limit on distal axial advancement of theproximal end104 ofimplant100. Thus, theguide tube130 preferably does not extend sufficiently far proximally from thedistal end102 to interfere with optimal opening of theimplant100. The specific dimensions are therefore relative, and will be optimized to suit a particular intended application. In one embodiment, theimplant100 has an implanted outside diameter within the range of from about 5 mm to about 45 mm, and an axial implanted length within the range of from about 5 mm to about 45 mm. Theguide tube130 has an overall length of about 3 mm to about 35 mm, and an outside diameter of about 0.095 inches. Additional disclosure relating to this embodiment is discussed below, relating toFIGS. 11A and 11B.
• An alternate embodiment of aguide tube130 is schematically illustrated inFIGS. 12A and 12B. In this configuration, theguide tube130 comprises a plurality oftubular segments134 spaced apart by at least one interveningspace136. This allows increased flexibility of theguide tube130, which may be desirable during the implantation step, while retaining the ability of theguide tube130 to maintain linearity of thecore304 while under axial pressure. Although threesegments134 are illustrated inFIG. 12A and four segments are illustrated inFIG. 12B, as many as10 or20 ormore segments134 may be desirable depending upon the desired flexibility of the resulting implant. Each adjacent pair ofsegments134 may be joined by ahinge element138 which permits lateral flexibility. In the illustrated embodiment ofFIG. 12A, thehinge element138 comprises an axially extending strip orspine138, which provides column strength along a first side of theguide tube130. Theguide tube130 may therefore be curved by compressing a second side of theguide tube130 which is generally offset from thespine138 by about 180°. A limit on the amount of curvature may be set by adjusting the axial length of thespace136 betweenadjacent segments134. As illustrated inFIG. 12B, an embodiment of aguide tube130 may have eachaxial spine138 be rotationally offset from the next adjacentaxial spine138 to enable flexibility of theoverall guide tube130 throughout a 360° angular range of motion.
• Alternatively, theflexible hinge point138 between eachadjacent segment134 may be provided by cutting a spiral groove or plurality of parallel grooves in a tubular element in between what will then become each adjacent pair ofsegments134. In this manner, eachtubular element134 will be separated by an integral spring like structure, which can permit flexibility. As a further alternative, the entire length of theguide tube130 may comprise a spring. Each of the forgoing embodiments may be readily constructed by laser cutting or other cutting from a piece of tube stock, to produce a onepiece guide tube130. Alternatively, theguide tube130 may be assembled from separate components and fabricated together using any of a variety of bonding techniques which are appropriate for the construction material selected for the tube320.
• Variousdistal end102 constructions may be utilized, as will be apparent to those of skill in the art in view of the disclosure herein. In the illustrated embodiment, thedistal implant plug124 extends within theimplant100 and is attached to the distal end of theguide tube130. Theimplant plug124 may be secured to theguide tube130 andimplant100 in any of a variety of ways, depending upon the various construction materials. For example, any of a variety of metal bonding techniques such as a welding, brazing, interference fit such as threaded fit or snap fit, may be utilized. Alternatively, any of a variety of bonding techniques for dissimilar materials may be utilized, such as adhesives, and various molding techniques. In one construction, theimplant plug124 comprises a molded polyethylene cap, and is held in place utilizing adistal cross pin140 which extends through theimplant100, theguide tube130 and theimplant plug124 to provide a secure fit against axial displacement.
• Some left atrial appendage implants, such as some of those described in some of the embodiments above (for examples, seeFIGS. 11-12B) and below (e.g., seeFIG. 14-16B), include asingle guide tube130 at thedistal end102 of theimplant100 that connects to or engages an implant actuation shaft and provides axial load transmission from thedistal guide tube130 to theimplant100 at itsdistal end102. In some embodiments, the shaft may be animplant actuation shaft334, an axiallymoveable core304 orrotatable core342.
• When the implant actuation shaft is particularly flexible or relatively long for actuation of along implant100, it could buckle if not adequately supported within theimplant100. To prevent bending or buckling of theimplant actuation shaft334, support preferably is provided only inside theimplant100 in order to maintain the interface with acatheter system300 proximal and adjacent to theimplant100 as flexible as possible. Given the continuously changing length of theimplant100 depending on its expansion state, a support member that also changed length with theimplant100 would be useful as well.
• FIGS. 13A and 13B illustrate an alternate embodiment of -animplant100, which includesmultiple guide tubes162,164. Theimplant100 includes two substantially concentric or axially alignedtelescoping guide tubes162,164, which are slidably moveable with respect to one another. Theouter guide tube162 is attached to the implant'sdistal end102 or may be integrally formed therewith, and theinner guide tube164 is attached to itsproximal end104 or may be integrally formed therewith, although in other embodiments they are attached to proximal and distal ends, respectively. In a concentric embodiment, theouter guide tube162 has an internal diameter sufficiently large enough to contain the outer diameter of theinner guide tube164. In certain embodiments, thetelescoping guide tubes162 and164 perform a support function when each is anchored at either thedistal end102 orproximal end104 of theimplant100 and by freely floating at the interface betweentelescoping guide tubes162 and164.
• Theouter guide tube162 and theinner guide tube164 are sized to allow full support of animplant actuation shaft334 without increasing the collapse force used to reduce the implant's diameter. Thetelescoping guide tubes162 and164 can be utilized with embodiments having a disconnect mount236 (seeFIGS. 17-21), tethered embodiments, or any other embodiments disclosed herein.
• Referring toFIG. 13A, when theimplant100 is in a radially reduced state, theinner guide tube164 overlaps theouter guide tube162, as shown. Alternatively, theinner guide tube164 may not overlap with theouter guide tube162 in the radially reduced state of theimplant100. Referring toFIG. 13B, when theimplant100 is radially expanded, theinner guide tube164 slides into theouter guide tube162 as the overall length of theimplant100 is axially shortened. Theouter guide tube162 can have a flared end to facilitate collapse of theimplant100. A flared end of theouter guide tube162 can help guide theinner guide tube164 during expansion. Similarly, theinner guide tube164 can have a tapered end.
• In some embodiments of animplant100 with multiple guide tubes, either of theouter guide tube162 or theinner guide tube164 may also be adistal guide tube130 or aproximal guide tube160. Theouter guide tube162 can be adistal guide tube130 attached at its distal end to thedistal end102 of theimplant100, and theinner guide tube164 can be aproximal guide tube160 attached at its proximal end to theproximal end104 of theimplant100. Theouter guide tube162 may include a mating surface on or near its distal end to engage a mating surface on thedistal hub108, or elsewhere on theimplant100.
• Relative proximal and distal movement of theinner guide tube164 andouter guide tube162 is preferably limited by a motion limit. In one embodiment, the motion limit includes at least one cross pin. In other embodiments, the motion limit includes at least one flare, annular ring, bump, or other suitable mechanism as is well known to those of skill in the art. Theouter guide tube162 slidably engages theinner guide tube164, which preferably enters the proximal end of theouter guide tube162. One advantage of this embodiment is a reduction in the likelihood that the insertion of animplant actuation shaft334 into theimplant100 will bind on the proximal end ofdistal guide tube130 while assembling aimplant delivery system50 or while attempting to recapture adetached implant100. Alternatively, in another embodiment, theouter guide tube162 can be attached at its proximal end to theproximal end104 of theimplant100, and theinner guide tube164 can be attached at its distal end to thedistal end102 of theimplant100.
• In an embodiment of animplant100 with multiple guide tubes, thedistal guide tube130 has a distalguide tube lumen132 and theproximal guide tube160 has a proximalguide tube lumen170. Theselumens132 and170 may contain radiopaque or contrast materials injected into thecatheter system300 through ports in thedeployment handle400. Theproximal guide tube160 may have awindow170 that passes through the wall of theproximal guide tube160. Thewindow170 may be used to release contrast materials in the proximalguide tube lumen170 toward theproximal end104 of theimplant100. Thiswindow170 may also be used as an anchor point or port through which apull wire312 from acatheter system300 may be used to secure theimplant100 prior to detachment.
• In certain embodiments of animplant100 with multiple guide tubes, aslideable engagement surface166 of theouter guide tube162 may interface with aslideable engagement surface168 of theinner guide tube164. Various embodiments of theouter guide tube162 andinner guide tube164 may comprise generally circular cross sections which allow free rotation about the concentric axis of the guide tubes along the generally coaxial cylindrical slideable engagement surfaces166 and168. Alternatively, other embodiments may have slideable engagement surfaces166 and168 which are elliptically-shaped or contain certain key and slot configurations or similar interface configurations known in the art to prevent or reduce relative rotation between theouter guide tube162 andinner guide tube164. Depending on how the guide tubes are attached to the ends of theimplant100, these rotation-inhibiting embodiments may provide additional support to reduce rotation in theframe101 of theimplant100.
• In some embodiments of theimplant actuation shaft334, the shaft may be an axiallymoveable core304, arotatable core342, or a shaft that uses an unscrew-to-release mechanism similar to an embodiment as illustrated inFIG. 14 (see below). By using twotelescoping guide tubes130 and160, the free detensioned length of theimplant100 can be doubled.
• Further advantages of multiple guide tube embodiments are described in the context of an improved implant release and recapture mechanism.
• 2. Implant Release and Recapture Mechanisms
• Various embodiments of implant release and recapture mechanisms provide an interface between an implant and a catheter system used to deploy, detach, and recapture the implant.
• a. Pull Wire Mechanisms
• Referring back toFIG. 11, there is illustrated an embodiment of animplant delivery system50 with adetachable implant100, an implant release and recapturemechanism200, acatheter system300, and adeployment handle400. As illustrated in this embodiment, the implant release and recapturemechanism200 includes a release element, such as apull wire312, which keeps theproximal end104 of theimplant100 in tension. An axiallymoveable core304 simultaneously pushes against thedistal end102 of theimplant100. The combination of pulling on the implantproximal end104 while pushing on itsdistal end102 keeps theimplant100 in a compressed state. When either thecore304 is pulled proximally or thepull wire312 is allowed to move distally, the tension on the ends of theimplant100 is reduced, thereby allowing the spring loaded or shape memory material in theimplant100 to radially expand into its normal expanded state.
• In this embodiment, theproximal end104 of theimplant100 is provided with areleasable lock142 for attachment to apull wire312. Pullwire312 extends proximally throughout the length of thetubular body306 to a proximalpull wire control406 on thehandle402.
• As used herein, the term pull wire is intended to include any of a wide variety of structures which are capable of transmitting axial tension or compression such as a pushing or pulling force with or without rotation from theproximal end308 to thedistal end310 of thecatheter302. Thus, monofilament or multifilament metal or polymeric rods or wires, woven or braided structures may be utilized. Alternatively, tubular elements such as a concentric tube positioned within the outertubular body306 may also be used as will be apparent to those of skill in the art.
• In the illustrated embodiment inFIG. 11, thepull wire312 is releasably connected to theproximal end104 of theimplant100. This permits proximal advancement of the proximal end of theimplant100, which cooperates with a distal retention force provided by thecore304 against the distal end of the implant to axially elongate theimplant100 thereby reducing it from its implanted configuration to its reduced profile for implantation. The proximal end of thepull wire312 may be connected to any of a variety of pull wire controls406, including rotational knobs, levers and slider switches, depending upon the design preference.
• Theimplant delivery system50 thus permits theimplant100 to be maintained in a low crossing profile configuration, to enable transluminal navigation to a deployment site. Following positioning at or about the desired deployment site, proximal retraction of thecore304 enables theimplant100 to radially enlarge under its own bias to fit the surrounding tissue structure. Alternatively, the implant can be enlarged under positive force, such as by inflation of a balloon or by a mechanical mechanism. Once the clinician is satisfied with the position of theimplant100, such as by injection of dye and visualization using conventional techniques, thecore304 is proximally retracted thereby releasing thelock142 and enabling detachment of theimplant100 from thedeployment system300.
• If, however, visualization reveals that theimplant100 is not at the location desired by the clinician, proximal retraction of thepull wire312 with respect to thecore304 will radially reduce the diameter of theimplant100, thereby enabling repositioning of theimplant100 at the desired site. Thus, the present invention permits theimplant100 to be enlarged or reduced by the clinician to permit repositioning and/or removal of theimplant100 as may be desired.
• Theproximal end104 of theimplant100 is preferably provided with areleasable lock142 for attachment of thepull wire312 to thedeployment catheter302. In the illustrated embodiment inFIG. 11, thereleasable lock142 is formed by advancing thepull wire312 distally around aproximal cross pin146, and providing an eye or loop which extends around thecore304. As long as thecore304 is in position within theimplant100, proximal retraction of thepull wire312 will advance theproximal end104 of theimplant100 in a proximal direction. SeeFIG. 11A. However, following deployment, proximal retraction of the core304 such as by manipulation of thecore control404 will pull the distal end of the core304 through the loop on the distal end of thepull wire312. Thepull wire312 may then be freely proximally removed from theimplant100, thereby enabling detachment of theimplant100 from thedelivery system50 within a treatment site. SeeFIG. 11B.
• The embodiment illustrated inFIGS. 11, 11A and11B may impart bias to theimplant100 because the location of thecross pin146 creates a moment arm with respect to thecore304 when tension is applied to thepull wire312 in order to maintain theimplant100 in a radially-reduced configuration. Tension through thepull wire312 may be on the order of six pounds of force, which when loaded off-center by thepull wire312 over the distance between the center of the core304 over thecross pin146 may result in significant torque and bias on theimplant100 while it is being deployed in theLAA10. This bias may result in deflection in thedelivery system50 which may cause theimplant100 to jump, move, rotate, etc., when released from thecatheter system300 during detachment.
• b. Threadable Torque Rod Mechanisms
• FIG. 14 illustrates an alternate embodiment of animplant deployment system50 in which animplant100 is radially enlarged or reduced by rotating a torque element extending throughout the deployment catheter. This embodiment of theimplant deployment system50 reduces the bias of moment arms described in the previous embodiment by eliminating off-center pull wires312 (as illustrated inFIGS. 11, 11A and B). Instead, the elongate flexibletubular body306 of thedeployment catheter302 includes arotatable torque rod340 extending axially therethrough. The proximal end of thetorque rod340 may be connected at a proximal manifold to a manual rotation device such as a hand crank, thumb wheel, rotatable knob or the like. Alternatively, thetorque rod340 may be connected to a power driven source of rotational energy such as a motor drive or air turbine. The distal end of thetorque rod340 is integral with or is connected to arotatable core342 which extends axially through theimplant100. Adistal end344 of therotatable core342 is positioned within acavity132 as has been discussed.
• The terms torque rod or torque element are intended to include any of a wide variety of structures which are capable of transmitting a rotational torque throughout the length of a catheter body. For example, solid core elements such as stainless steel, nitinol or other nickel titanium alloys, or polymeric materials may be utilized. In an embodiment intended for implantation over a guidewire, thetorque rod340 is preferably provided with an axially extending central guidewire lumen. This may be accomplished by constructing thetorque rod340 from a section of hypodermic needle tubing, having an inside diameter of from about 0.001 inches to about 0.005 inches or more greater than the outside diameter of the intended guidewire.Tubular torque rods340 may also be fabricated or constructed utilizing any of a wide variety of polymeric constructions which include woven or braided reinforcing layers in the wall. Torque transmitting tubes and their methods of construction are well understood in the intracranial access and rotational atherectomy catheter arts, among others, and are not described in greater detail herein.
• Use of atubular torque rod340 also provides a convenient infusion lumen for injection of contrast media within theimplant100, such as through aport343 orlumen350. In one embodiment, axiallymoveable core304 also includes alumen350. Thelumen350 preferably allows visualization dye to flow through thelumen350 of the axiallymoveable core304, through thelumen150 of theimplant end cap148, and into the leftatrial appendage10. Such usage of visualization dye is useful for clinical diagnosis and testing of the position of theimplant100 within the leftatrial appendage10 or other body opening, as described in greater detail below.
• Themarker360 as shown inFIG. 14 advantageously assists in locating the position of thedistal end344 of the axiallymoveable core342. In one embodiment,marker360 comprises a radiopaque band press fit onto thedistal end344 of the axiallymoveable core342.Marker360 preferably is made from a material readily identified after insertion into a patient's body by using visualization techniques that are well known to those of skill in the art. In one embodiment, themarker360 is made from gold, or tungsten, or any such suitable material, as is well known to those of skill in the art. In another embodiment,marker360 is welded, soldered, or glued onto thedistal end344 of the axiallymoveable core342. In one embodiment,marker360 is an annular band and surrounds the circumference of the axiallymoveable core342. In other embodiments, themarker360 does not surround the circumference of the axiallymoveable core342. In other embodiments,marker360 includes evenly or unevenly spaced marker segments. In one embodiment, the use of marker segments is useful to discern the radial orientation of theimplant100 within the body.
• Theproximal end104 of theimplant100 is provided with a threadedaperture346 through which thecore342 is threadably engaged. As will be appreciated by those of skill in the art in view of the disclosure herein, rotation of the threadedcore342 in a first direction relative to theproximal end104 of theimplant100 will cause therotatable core342 to advance distally. This distal advancement will result in an axial elongation and radial reduction of theimplantable device100. Rotation of therotatable core342 in a reverse direction will cause a proximal retraction of therotatable core342, thus enabling a radial enlargement and axial shortening of theimplantable device100.
• Thedeployment catheter302 is further provided with ananti-rotation lock348 between adistal end310 of thetubular body306 and theproximal end104 of theimplant100. In general, therotational lock348 may be conveniently provided by cooperation between afirst surface352 on thedistal end310 of thedeployment catheter302, which engages asecond surface354 on theproximal end104 of theimplant100, to rotationally link thedeployment catheter302 and theimplantable device100. Any of a variety of complementary surface structures may be provided, such as an axial extension on one of the first352 andsecond surfaces354 for coupling with a corresponding recess on the other of the first352 andsecond surfaces354. Such extensions and recesses may be positioned laterally offset from the axis of thecatheter302. Alternatively, they may be provided on the longitudinal axis with any of a variety of axially releasable anti-rotational couplings having at least one flat such as a hexagonal or other multifaceted cross-sectional configuration.
• Upon placement of theimplant100 at the desired implantation site, thetorque rod340 is rotated in a direction that produces an axial proximal retraction. This allows radial enlargement of the radially outwardlybiased implant100 at the implantation site. Continued rotation of thetorque rod340 will cause the threadedcore342 to exit proximally through the threadedaperture346. At that point, thedeployment catheter302 may be proximally retracted from the patient, leaving the implanteddevice100 in place.
• By modification of the decoupling mechanism to allow thecore342 to be decoupled from thetorque rod340, therotatable core342 may be left within theimplant100, as may be desired depending upon the intended deployment mechanism. For example, the distal end of thecore342 may be rotatably locked within theend cap148, such as by including complimentary radially outwardly or inwardly extending flanges and grooves on the distal end of thecore342 and inside surface of thecavity132. In this manner, proximal retraction of thecore342 by rotation thereof relative to theimplant100 will pull theend cap148 in a proximal direction under positive force. This may be desirable as a supplement to or instead of a radially enlarging bias built into theimplant100.
• In other embodiments, thetorque rod340 is threaded at its distal end. The distal end is threaded into a sliding nut located within a guide tube extending from the distal end of theimplant100. Such embodiments are described in greater detail in U.S. application Ser. No. 10/642,384, filed Aug. 15, 2003, published as U.S. Publication No. 2005/0038470, which is expressly incorporated by reference herein. Another embodiment of an implant deployment system that could include a torque rod threaded at its distal end in a manner similar to an embodiment illustrated inFIG. 16A.
• Theimplant100 may also be retrieved and removed from the body in accordance with a further aspect of the present invention. One manner of retrieval and removal is described with respect to FIGS.15A-E. Referring toFIG. 15A, an implanteddevice100 is illustrated as releasably coupled to the distal end of thetubular body306, as has been previously discussed. Coupling may be accomplished by aligning thetubular body306 with theproximal end104 of the deployedimplant100, under fluoroscopic visualization, and distally advancing arotatable core342 through the threadedaperture346. Threadable engagement between therotatable core342 andaperture346 may thereafter be achieved, and distal advancement ofcore342 will axially elongate and radially reduce theimplant100.
• Thetubular body306 is axially movably positioned within an outer tubular delivery orretrieval catheter502. In various embodiments, theretrieval catheter502 may be separate and distinct from the delivery ordeployment catheter302, or theretrieval catheter502 may be coaxial with the delivery ordeployment catheter302, or theretrieval catheter502 may be the same catheter as the delivery ordeployment catheter302.Catheter502 extends from a proximal end (not illustrated) to adistal end506. Thedistal end506 is preferably provided with a flared opening, such as by constructing a plurality ofpetals510 for facilitating proximal retraction of theimplant100 as will become apparent.
• Petals510 may be constructed in a variety of ways, such as by providing axially extending slits in thedistal end506 of thecatheter502. In this manner, preferably at least about three, and generally at least about four or five or six petals or more will be provided on thedistal end506 of thecatheter502.Petals510 manufactured in this manner would reside in a first plane, transverse to the longitudinal axis of thecatheter502, if each ofsuch petals510 were inclined at 90 degrees to the longitudinal axis of thecatheter502.
• In one embodiment, a second layer ofpetals512 are provided, which would lie in a second, adjacent plane if thepetals512 were inclined at 90 degrees to the longitudinal axis of thecatheter502. Preferably, the second plane ofpetals512 is rotationally offset from the first plane ofpetals510, such that thesecond petals512 cover thespaces514 formed between each adjacent pair ofpetals510. The use of two or more layers of staggeredpetals510 and512 has been found to be useful in retrievingimplants100, particularly when theimplant100 carries a plurality of tissue anchors118. However, in many embodiments, theretrieval catheter502 includes only a single plane ofpetals510, such as illustrated inFIG. 15B.
• Thepetals510 and512 may be manufactured from any of a variety of polymer materials useful in constructing medical device components such as thecatheter502. This includes, for example, polyethylene, PET, PEEK, PEBAX, and others well known in the art. Thesecond petals512 may be constructed in any of a variety of ways. In one convenient construction, a section of tubing which concentrically fits over thecatheter502 is provided with a plurality of axially extending slots in the same manner as discussed above. The tubing with a slotted distal end may be concentrically positioned on thecatheter502, and rotated such that the space betweenadjacent petals512 is offset from the space betweenadjacent petals510. The hub of thepetals512 may thereafter be bonded to thecatheter502, such as by heat shrinking, adhesives, or other bonding techniques known in the art.FIG. 15B shows a perspective view of an embodiment of a single layer ofpetals510 which is coaxial with atransseptal catheter520 and animplant actuation shaft334. Theimplant actuation shaft334 can berotatable core342 as illustrated inFIG. 15A.
• The removal sequence will be further understood by reference toFIGS. 15C through 15E. Referring toFIG. 15C, the radially reducedimplant100 is proximally retracted part way into theretrieval catheter502. This can be accomplished by proximally retracting thetubular body306 and/or distally advancing thecatheter502. As illustrated inFIG. 15D, thetubular body306 having theimplant100 attached thereto is proximally retracted a sufficient distance to position the tissue anchors118 within thepetals510. The entire assembly of thetubular body306, within theretrieval catheter502 may then be proximally retracted within thetransseptal sheath520 or other tubular body as illustrated inFIG. 15E. The collapsedpetals510 allow this to occur while preventing engagement of the tissue anchors118 with the distal end of thetransseptal sheath520 or body tissue. The entire assembly having theimplant100 contained therein may thereafter be proximally withdrawn from or repositioned within the patient.
• The embodiments illustrated inFIGS. 14 and 15 may impart bias to theimplant100 because relative rotation between thecatheter system300 and theimplant100 is required in order to release the threaded locking system described above. When theimplant100 is to be radially expanded within theLAA10 thetorque rod342 must be rotated with respect to the threadedaperture346 in theimplant100. The rotation of the rod with respect to the implant may result in torque, causing a rotational bias in theimplant100 with respect to theLAA10 as well as with respect to thecatheter system300. This bias may result in deflection in thedelivery system50 which may cause theimplant100 to “jump” or “spin” when released from thecatheter system300 during detachment.
• c. Axial Decoupling Mechanisms
• FIGS. 16A and 16B illustrate another embodiment of animplant delivery system50. Thesystem50 of the illustrated embodiment provides some axial decoupling between an axiallymoveable core304 and animplant100. This embodiment of theimplant deployment system50 reduces the bias of torsion loads described in the previous embodiment by eliminating rotational forces related to a threaded engagement between animplant100 and a catheter system300 (as illustrated inFIGS. 14 and 15). Furthermore, it is clinically advantageous to provide axial decoupling between the axiallymoveable core304 and theimplant100 is because axial decoupling assures that movement of the axiallymoveable core304, as well as other components of the adjustableimplant delivery system50 that are coupled to the axially moveable core304 (for example, but not limited to thedeployment handle400 and thecatheter system300, described further herein), do not substantially affect the shape or position of theimplant100. Such axial decoupling prevents inadvertent movement of the axiallymoveable core304 or deployment handle400 from affecting the shape or position ofimplant100.
• For example, in one embodiment, if the user inadvertently pulls or pushes the axiallymoveable core304 or thedeployment handle400, the position of theimplant100 within the leftatrial appendage10 preferably will not be substantially affected. In addition, axial decoupling also preferably prevents the motion of a beatingheart5 from translating into movement of the axiallymoveable core304, thecatheter300, and/or the components coupled to the axiallymoveable core304 andcatheter300, including thedeployment handle400. By decoupling theimplant100 from the axiallymoveable core304 and other components coupled to the axiallymoveable core304, the risk of accidentally dislodging theimplant100 from the leftatrial appendage10 is reduced.
• The illustrated implant release and recapturemechanism200 ofFIGS. 16A and 16B provides quick-disconnect functionality for release of axiallymoveable core304 fromguide tube130 by using non-rotational forces. As illustrated, the implant release and recapturemechanism200 includes aguide tube130, which comprises at least oneslot154. Two opposingslots154 are shown in the embodiment ofFIGS. 16A and 16B. Axiallymoveable core304 is coupled to guidetube130 by quick-disconnect functionality.
• Axiallymoveable core304 in this embodiment includes aretractable lock220 in the form of anelongate key222 extending through the lumen of thecore304, and two opposingports224 in axiallymoveable core304 through which twotabs226 extend. Thedistal tip228 of the key222 includes acontact surface230 operable to engagecontact surfaces232 of thetabs226. The key222 is moveable relative to the axiallymoveable core304, and can be moved distally such thatcontact surface230 engages contact surfaces232 oftabs226, translating into radial movement oftabs226. Radial movement oftabs226 causes them to project intoslots154 of theguide tube130 by bending radially outwardly, and extending in a substantially radial direction. In one embodiment, the key222 is secured in place relative to the axiallymoveable core304, so that thetabs226 remain projected into theslots154 of theguide tube130. With thetabs226 secured in place, axial movement of axiallymoveable core304 preferably is limited by interference between thetabs226 and the proximal anddistal surfaces156,158 ofguide tube130.
• In one embodiment, the key222 is made from an elongate wire, rod, or tube flexible enough for delivery through the adjustableimplant delivery system50 described above, and strong enough to apply enough force totabs226 to achieve the functionality described above. In one embodiment, the key222 is made from stainless steel. The key222 preferably is locked in place relative to the axiallymoveable core304 by using a control, such as a thumbswitch or other such device as is well known to those of skill in the art. For example, in one embodiment, the axiallymoveable core304 is secured to the proximal portion of a deployment handle400 (not shown) such that the position of the axiallymoveable core304 is fixed with respect to thedeployment handle400. A key222 preferably is inserted inside of the axiallymoveable core304 such that it may slide axially within the axiallymoveable core304. The proximal portion of the key222 preferably is coupled to a control, such as, for example, a thumbswitch. The thumbswitch preferably is provided such that it may slide axially with respect to the deployment handle400 (and therefore with respect to the axially moveable core304) over a predetermined range. By coupling the thumbswitch to the proximal portion of the key222, axial movement of the key222 with respect to the axiallymoveable core304 is achieved over the predetermined range. In addition, by locking the thumbswitch in place (by using mechanisms well known to those of skill in the art, such as release buttons, tabs, or their equivalents), the key222 may be locked in place with respect to the axiallymoveable core304. Alternatively, switches, levers, buttons, dials, and similar devices well known to those of skill in the art may be used instead of a thumbswitch as the control for theretractable lock220.
• To decouple axiallymoveable core304 from theguide tube130,retractable lock220 is released by movingkey222 proximally relative to axiallymoveable core304, thereby removing radial forces fromcontact surfaces232 oftabs226. In one embodiment,tabs226 are biased to bend inward upon the removal of the radial forces from their contact surfaces232. For example,tabs226 preferably are constructed from a spring material, or a shape memory metal, such as, for example, nickel titanium. Alternatively, in another embodiment, key222 is moved distally to decouple axiallymoveable core304 from theguide tube130. For example, in one embodiment, key222 includes a cutout, notch, or slot along at least a portion of its distal end. In one embodiment, as the key222 is moved distally, the cutout, notch, or slot is moved such that it engages thetabs226, allowing them to flex inwardly preferably under their own bias. In another embodiment,tabs226 are biased to bend outward upon removal of a radial force from acontact surface232, and bend inward upon application of a radial force to contactsurface232. In such embodiment, the key222 preferably is advanced distally to apply force on acontact surface232 such thattabs226 are directed inward. In one embodiment, the key222 is advanced proximally to apply force on acontact surface232 such thattabs226 are directed inward.
• In other embodiments, aguide tube130 need not be connected to theimplant100, and for example, can be provided as part of the axiallymoveable core304, or even the deployment handle402 in order to decouple axial movement between theimplant100 and the rest of thedelivery system50. For example, in one embodiment, an axially moveable core may include two concentric or axially aligned tubes, slidably moveable with respect to one another, such as, for example, an outer tube and an inner tube, such as describe above with respect toFIGS. 13A and 13B. The outer tube may include a mating surface on or near its distal end to engage a mating surface on the distal hub, or elsewhere on the implant. The outer tube slidably engages an inner tube, which enters the outer tube at the outer tube's proximal end. In one embodiment, a solid core is used instead of an inner tube. Relative proximal and distal movement of the inner and outer tube is preferably limited by a motion limit.
• In one embodiment, the motion limit includes at least one cross pin. In other embodiments, the motion limit includes at least one flare, annular ring, bump, or other suitable mechanism as is well known to those of skill in the art. The inner tube extends preferably to a handle as described above for operating the axially moveable core. The engagement of the outer tube and the inner tube of the axially moveable core may occur anywhere between the handle and the implant along the length of the core.
• In another embodiment, the inner tube includes a mating surface on its distal end to engage a mating surface on the distal hub of the implant. The inner tube slidably engages an outer tube, which at least partially covers the inner tube at the inner tube's proximal end. Relative proximal and distal movement of the inner and outer tube is preferably limited by a motion limit as described above, with the outer tube extending outside of the patient and operably connected to a handle.
• d. Multiple Guide Tube Mechanisms
• Again referring toFIGS. 13A and 13B, various embodiments of a multiple guide tube system may provide additional buckling and bending support for anyimplant actuation shaft334 traversing an axis of animplant100, as described above. Also, providing dual, opposed guide tube allows decoupling of implant motion with respect to the delivery catheter over a longer axial distance. For example, a single guide tube having may allow for axial movement decoupling over the length of the single guide tube, but dual guide tubes allow for axial movement decoupling over the length defined by both guide tubes.
• Single guide tube embodiments are illustrated inFIGS. 16A and 16B, and described in U.S. application Ser. No. 10/642,384, filed Aug. 15, 2003, published as U.S. Publication No. 2005/0038470, incorporated by reference herein. Implants including single guide tubes generally include a nut that is configured to slide within the guide tube along a limited axial range of motion. A tab, or protrusion, generally extends from the external side wall of the nut into a slot provided in the guide tube wall. The interference between the tab and the slot defines an axial range of motion provided by the guide tube/sliding nut assembly. An axial moveable core, or a torque rod, is generally coupled to the nut (e.g., a threaded portion of the core screws into a mating portion of the nut), and an implant is generally coupled to the distal end of the single guide tube; therefore, the axial range of motion defined by the guide tube/sliding nut assembly also defines an axial range of motion between the axial moveable core and the implant.
• The axial range of motion between the axial moveable core and the implant defines a distance over which axial movement of the implant is decoupled from the axial moveable core. This decoupling distance provides many clinical advantages. For example, once the implant is expanded within the patient's heart, such as within the LAA, it generally remains attached to the axial moveable core. By remaining attached to the axial moveable core the clinician can verify the implant position and sealing against the LAA wall prior to final deployment, or release, from the axial moveable core.
• Forces provided by the patient's moving heart act upon the core-coupled implant. It is desirable that the implant is free to move with the movement. of the patient's beating heart, and that the implant does not resist such forces. Resistance to heart movement could cause the implant to become dislodged from its implantation site, or to change it orientation in an undesired manner.
• The guide tube/sliding nut assembly of the single guide tube embodiments addresses this issue by providing limited decoupling between the implant and an axial moveable core, as discussed above. However, the decoupling length is generally limited by the length of the guide tube slot, which is limited by the guide tube length. It would be advantageous to increase the decoupling length. In one embodiment, decoupling length is increased by employing a dual guide tube configuration, such as described above with respect toFIGS. 13A and 13B, and below. In addition, a dual guide tube configuration can be employed with any of the deployment systems, delivery systems, implants, catheters, and catheter systems described herein.
• Although the embodiments ofFIGS. 13A and 13B illustrate one pull cord ortether312 configuration, certain preferred embodiments of animplant delivery system50 with a multiple guide tubes do not include apull cord312. Removing thetether312 can reduce system bias from moment arms. Instead, an embodiment of animplant delivery system50 with amultiple guide tubes130 and160, or164 and162, may be used with a threadedrod342 configuration as described above relating toFIGS. 14 and 15. In other embodiments, animplant delivery system50 with multiple guide tubes does not use a threaded torque rod configuration in order to reduce system bias from rotation of theimplant100 with respect to atorque rod342.
• In certain embodiments animplant delivery system50 with multiple guide tubes can provide for some axial load decoupling by providing slideable axial support to animplant100, which is attached at itsproximal end104 to acatheter system300. After animplant actuation shaft334 is withdrawn from thedistal end102 of an implant, the freely slideableconcentric guide tubes130 and160 (or162 and164) may absorb some of the axial loading caused by the beating of aheart5, thereby allowing theimplant100frame101 to deform with the beating of aheart5 without imparting a complete load to the remainder of theimplant delivery system50.
• In one embodiment, a multiple guide tube configuration may be used to simplify an implant release and recapturemechanism200. For example, the implant release and recapturemechanism200 provides extendable support to anon-threaded shaft334 that provides axial force to thedistal end104 of animplant100 without providing off-center moment arms or rotational loads relative to theimplant100 during implant deployment or detachment (such as is illustrated in one embodiment inFIGS. 21A-21C, as described below).
• In one embodiment, multiple guide tubes provide additional axial support and guided slidable surfaces to theimplant100 while preventing theshaft334 from buckling over a the guide tube lengths. Substantially coaxial tubes provide for easier alignment of theends102 and104 of animplant100, and simplify the re-insertion of ashaft334 into animplant100 during recapture of detached or deployed implants. In addition, the multiple guide tube configuration provides support for the distal loading provided by theshaft334, and works with any collapse or release mechanism. However, it would be advantageous to provide the necessary proximal loading to theproximal end104 of animplant100 in order to radially reduce animplant100 in a manner that did not impart moment arms or rotational loads to theimplant100 during deployment or detachment, as described in the following embodiments.
• e. Concentric Collapse and Release Mechanisms
• FIGS. 17-21 illustrate cross-sectional views of various embodiments of the distal end of animplant delivery system50 that includes animplant100, an implant release and recapturemechanism200, and acatheter system300, which is attachable to a deployment handle400 (not illustrated). The illustrated embodiments provide mechanisms to release animplant100 from acatheter system300 such that the implant's position and orientation do not change as a result of the release process. For example, the illustrated embodiments reduce bias and moment arms that cause deformation of theimplant100 and loads within theimplant delivery system50. Such bias and moment arms can cause theimplant100 to jump or change orientation when released from theimplant delivery system50. These embodiments include a flexible interface between theimplant100 and thecatheter system300. They also reduce off-axis loading, thereby reducing moment arms and bending bias within thesystem50. Some embodiments include atether line210 system (not shown) or atorque rod340 configuration (not shown), as described above.
• Referring toFIGS. 17-20, the illustrated embodiments have animplant100 with aframe101, aproximal end104 and adistal end102, a stoppingsurface126 at thedistal end102 of theimplant100, and adisconnect mount interface180 on theproximal end104 of theimplant100. The implant ofFIGS. 17-20 is schematically shown, and may have any suitable configuration as described herein. Thedisconnect mount interface180 has afinger interface182 which interacts with aflexible finger238 on adisconnect mount236 on thecatheter system300, as described below. Embodiments of thefinger interface182 may be in the form of a protruding finger, an interlocking feature, a groove, a slot, a window, or other similar features for releasably holding adisconnect mount236flexible finger238. Thedistal end102 of theimplant100 may also have anend cap148. Various embodiments and combinations of embodiments of theimplant100 may be used, including but not limited to single and multiple guide tube configurations, as describe above.
• In some embodiments, thecatheter system300 includes adisconnect mount236 provided on thedistal end310 of adelivery catheter302. Thedisconnect mount236 may be any mechanical mount that releases one body from another without creating any or substantial moment arms or bending bias. Thedisconnect mount236 may provide releaseable concentric tension or concentric loading to animplant100. The loading imparted by thedisconnect mount236 to theimplant100 may be in a proximal or distal direction. Distal loading may be imparted to advance theentire catheter system300 andimplant100 distally into aheart5. Proximal loading may be used in conjunction with a distally-loading shaft that works with thedisconnect mount236 in placing animplant100 in tension in order to radially reduce a diameter of theimplant100. In one embodiment, adisconnect mount236 may include an annular ring, which may be controlled to switch between an expanded and a reduced diameter configuration. In one embodiment, thedisconnect mount236 acts like a stent, such as by radially expanding or contracting. For example, thedisconnect mount236 can include a shape memory alloy, such as nickel titanium, which self-expands. In other embodiments, thedisconnect mount236 expands under positive force, such as in response to radial forces provided by an inflation balloon.
• The terms “concentric tension,” “concentric loading,” and “concentric force” are broad terms intended to have their ordinary meanings. In addition, these terms refer to forces that are provided either in an inward or outward direction with respect to a longitudinal axis, and forces symmetrical about a longitudinal axis. Some of the symmetrical forces may be in directions with components along an axis extending distally or proximally along the longitudinal axis, and may also be perpendicular to the longitudinal axis. For example, in one embodiment, a disconnect mount is a generally cylindrical structure having a longitudinal axis and flexible fingers extending longitudinally from its end. The flexible fingers are generally biased to flex inward, towards the longitudinal axis, or outward, away from the longitudinal axis. The fingers are generally aligned with openings in a mating portion of the implantable device. The openings generally extend around or within a portion of the circumference of the mating portion of the implantable device. As the fingers flex, they provide concentric force that maintains a portion of the fingers within the windows of the implant mating surface. When the fingers are engaged with the implant mating portion, proximal or distal force can thereafter be applied to the implant with the disconnect mount to move the implant, or at least the portion of the implant coupled to the disconnect mount, in a proximal or distal direction.
• Concentric forces can be used to release the implant from a delivery system without applying bias to the implant, as described herein. For example, by concentrically releasing tension from the proximal end of the implant, the implant will not substantially jump, move, or otherwise change its orientation with respect to the delivery system when released.
• In some embodiments, the disconnect mount includes two, three, four, or a plurality of actuating fingers, such as ten or more actuating fingers. As illustrated, thedisconnect mount236 has at least twoflexible fingers238 which engage recesses, windows, or corresponding structure in adisconnect mount interface180 located at theproximal end104 of animplant100.
• Thedisconnect mount236 can be created from rod stock using a combination Swiss screw machine and Electrical Discharge Machining (EDM) operation to fashion at least two substantiallysymmetric flex fingers238 with protrudingportions240. Thedisconnect mount interface180 may have afinger interface182 that is specially adapted to releasably hold adisconnect mount236flexible finger238 in place. Thecatheter system300 has animplant actuation shaft334 that extends through thecatheter body302 and through theimplant100 to touch the stoppingsurface126 at thedistal end102 of theimplant100. When theimplant actuation shaft334 provides a sufficient load in the distal direction against the stoppingsurface126 while a tensile load in a proximal direction is applied to theproximal end104 of theimplant100, theimplant100 can be held in a radially-reduced configuration which overcomes the normal shape-memory bias toward a radially-expanded configuration for theimplant100.
• When theimplant actuation shaft334 is retracted proximally into thecatheter body302, theimplant100 tends to return to its radially-expanded configuration by moving proximally (e.g., seeFIGS. 17, 19,20). When the tensile loading on theproximal end104 of theimplant100 is reduced by allowing theproximal end104 of the implant to move distally, theimplant100 tends to return to its radially-expanded configuration by moving distally (e.g., seeFIGS. 18, 21). The retraction of theimplant actuation shaft334 and reduction in tensile loading on theproximal end104 of theimplant100 may occur independently, simultaneously, or incrementally to control the relative axial placement of theimplant100 in aLAA10.
• Still referring toFIGS. 17-20, there is illustrated various embodiments of adisconnect mount236 with a correspondingdisconnect mount interface180 and alock tube234. Thedisconnect mount interface180 may have afinger interface182 that is adapted to releasably hold adisconnect mount236flexible finger238 in place. The protrudingportions240 of theflex fingers238 are captured within cutouts, recesses, or windows located on thefinger interface182 of thedisconnect mount interface180, which is located on aproximal portion104 of theimplantable device100. For example, the implant's100finger interface182 can include cutouts that releasably engageflex fingers238 of the delivery system. While theflex fingers238 hold on to theproximal end104 of theimplant100, animplant actuation shaft334 extends through theimplant100 and pushes distally against thedistal end102 of theimplant100. As described above, theimplant100 can be made self-expanding, so that when the distal pushing force exerted by theimplant actuation shaft334 or the proximal pulling (or holding) force applied by theflex fingers238 is removed theimplant100 automatically radially expands to a predetermined size and shape. Theimplant100 can be maintained in its reduced diameter configuration by holding theproximal end104 of theimplant100 with theflex fingers238 and pushing against thedistal end102 of theimplant100 with theimplant actuation shaft334. In this configuration, relative movement between the innerimplant actuation shaft334 and the concentric,outer flex fingers238 controls implant100 expansion and collapse.
• An embodiment offlex fingers238 can be biased to extend either radially inwardly or radially outwardly. In embodiments where theflex fingers238 are biased to extend radially inwardly, theflex fingers238 engage adisconnect mount interface180 to lock animplant100 to theimplant delivery system50 when a structure prevents theflex fingers238 from extending radially inwardly. In one embodiment theflex fingers238 are held in place with adisconnect mount interface180 of theimplant100 by the presence of animplant actuation shaft334 which extends through theimplant100 and prevents theflex fingers238 from extending radially inwardly. When theimplant actuation shaft334 is withdrawn proximally toward thecatheter system300 past thedisconnect mount236, the open space created by the removal of theimplant actuation shaft334 leaves room for theflex fingers238 to extend radially inwardly under its bias. This radial movement of theflex fingers238 releases thedisconnect mount236 from thedisconnect mount interface180, thereby releasing theimplant100 from theimplant delivery system50.101631 In embodiments where theflex fingers238 are biased to extend radially outwardly, theflex fingers238 engage adisconnect mount interface180 to lock animplant100 to theimplant delivery system50 in its natural state. When a structure or a load causes theflex fingers238 to extend radially inwardly, the radial movement of theflex fingers238 releases thedisconnect mount236 from thedisconnect mount interface180, thereby releasing theimplant100 from theimplant delivery system50.101641 In some embodiments, theflex fingers238 are held in thefinger interface182 by alock tube234. Thelock tube234 can be axially slideable with respect to thecatheter body302 and with respect to adisconnect mount236. In one embodiment, thelock tube234 has a threaded portion (not illustrated) that threads into thedisconnect mount236 and extends under and between theflex fingers238, thereby preventing theflex fingers238 from collapsing inward (in a manner similar to the embodiment illustrated inFIGS. 17-18).
• In another embodiment thelock tube234 has a threaded portion (not illustrated) that threads over thedisconnect mount236 and extends over theflex fingers238, thereby preventing theflex fingers238 from expanding outward (in a manner similar to the embodiment illustrated inFIGS. 19-20). In other embodiments, alock tube234 can be threaded to acatheter body302, or alock tube234 may not be threaded and retains its axial positioning with respect to adisconnect mount236 until the user actuates the lock tube to release theflex fingers238. In other embodiments, animplant actuation shaft334 can include a protruding feature, such as a tab, key or pin, that engages alock tube234 and allows torque to be transferred from theimplant actuation shaft334 to thelock tube234.
• FIGS. 17A-17C illustrate an embodiment of adisconnect mount236 havingflex fingers238, a correspondingdisconnect mount interface180, and alock tube234 at least partially contained within acatheter body302. In certain embodiments illustrated inFIGS. 17A-17C, theflex fingers238 can be biased to extend radially outwardly or inwardly to apply concentric loading, as discussed above.
• In one embodiment, theflex fingers238 are biased outwardly. Theflex fingers238 can also include a proximalinclined surface242 at the transition from theflex finger238 to the protrudingportion240. Referring to embodiments inFIG. 17B, after theimplant100 is deployed or radially expanded in a LAA10 (not illustrated here), anchors118 (not illustrated here) on theimplant frame101 secure theimplant100 within theLAA10. The interface between theimplant100 and thedisconnect mount236 provides concentric loading to theimplant100. In one embodiment the concentric loading is concentric tension. At this point, thelock tube234 can be withdrawn proximally away from contact with theflex fingers238, allowing theflex fingers238 to deflect inwardly.
• When theflex fingers238 are moved proximally with respect to theimplant100, such as when thecatheter system300 is withdrawn proximally away from the expandedimplant100 in theLAA10, the inside edge of thedisconnect mount interface180 can press onto the proximalinclined surface242, which provides a radially inward force to theflex finger238. As illustrated, the embodieddisconnect mount interface180 uses afinger interface182 in the form of an internal surface of aproximal end104 of theimplant100. The radially inward force causes theflex fingers238 or at least a distal portion of theflex fingers238 to move radially inwardly.
• The amount of deflection in theflex fingers238 that effective to release thedisconnect mount236 from thedisconnect mount interface180 may depend on the thickness of thelock tube240 alone (as is illustrated inFIG. 17B), or it may depend on the removal of theimplant actuation shaft334 proximal to the flex fingers238 (as is illustrated inFIG. 17C) in order to release theimplant100. Once theflex fingers238 are sufficiently radially deflected, theimplant100 is disconnected from thedelivery system50 without imparting any Or any substantial moment arms, bending bias, or rotational bias with respect to theimplant100. As depicted inFIG. 17C, once theimplant100 is detached, theflex fingers238 will bias toward their natural state (inward bias is illustrated in solid lines and outward bias is illustrated in dotted lines).
• In another embodiment illustrated inFIGS. 17A-17C, theflex fingers238 are biased inwardly. Referring to embodiments inFIG. 17B, after theimplant100 is deployed and radially expanded in a LAA, anchors on theimplant frame101 secure theimplant100 within the LAA. The interface between theimplant100 and thedisconnect mount236 provides concentric loading to theimplant100. In one embodiment the concentric loading is concentric tension. At this point, thelock tube234 can be withdrawn proximally away from contact with theflex fingers238, allowing theflex fingers238 to deflect inwardly to their natural, biased state. The amount of deflection in theflex fingers238 that is effective to release thedisconnect mount236 from thedisconnect mount interface180 may depend on the thickness of thelock tube240 alone (as is illustrated inFIG. 17B), or it may depend on the removal of theimplant actuation shaft334 proximal to the flex fingers238 (as is illustrated inFIG. 17C) in order to release theimplant100. Once theflex fingers238 are sufficiently radially deflected, theimplant100 is disconnected from thedelivery system50 without imparting any or any substantial moment arms, bending bias, or rotational bias with respect to theimplant100. As depicted inFIG. 17C, once theimplant100 is detached, theflex fingers238 will bias toward their natural state (inward bias is illustrated in solid lines and outward bias is illustrated in dotted lines). When theflex fingers238 are biased inwardly, thelock tube334 can be slideably engaged under theflex fingers238 to deflect the fingers outwardly.
• In some embodiments, when theimplant100 is in its collapsed configuration the tension created by a load between theimplant actuation shaft334 and theflex fingers238 may create pullout forces sufficient to cause inward flex of theflex fingers238 and potentially pinch underlying structure, such as theimplant actuation shaft334, which could cause theimplant100 to bind. However, thelock tube234 can prevent this from happening and can serve as a buffer between theflex fingers238 and the underlyingimplant actuation shaft334. This provides smooth and uninterrupted movement of theimplant actuation shaft334 in and out of theimplant100 during expansion. It also allows for smooth disconnect during release of the implant100 (“boing-less” release, or releasing without the implant “jumping”, moving, or changing its position or orientation).
• In some embodiments,markers204 are provided at locations visible under fluoroscopy or other means known in the art of visualizing the manipulation or implantation of devices within a body. Themarkers204, which can be radiopaque in nature, can be placed on any surfaces to assist in deployment or recapture of animplant100, as is described above for the embodiment of amarker360 as shown inFIG. 14, which advantageously assists in locating the position of adistal end344 of an axiallymoveable core342. In various embodiments, amarker204 comprises a radiopaque band, dot, coating, or material that is attached to adisconnect mount236, adistal end104 of animplant100, and a portion of animplant actuation shaft334.Marker204 preferably is made from a material readily identified after insertion into a patient's body by using visualization techniques that are well known to those of skill in the art. In one embodiment, themarker204 is made from gold, or tungsten, or any such suitable material, as is well known to those of skill in the art. In another embodiment,marker204 is welded, soldered, or glued onto a structure for marking. In one embodiment, the use ofmarkers204 segments is useful to discern the radial orientation of theimplant100 within the body.
• Referring toFIGS. 18A-18C, there is illustrated an embodiment of adisconnect mount236 withflex fingers238, a correspondingdisconnect mount interface180, and alock tube234 at least partially contained within acatheter body302. The embodiment illustrated inFIGS. 18A-18C is similar in many ways with the embodiment illustrated inFIGS. 17A-17C, and includes many of the same components described above. The embodiment illustrated inFIGS. 18A-18C can optionally include markers (not illustrated). The illustrated embodiment also includes alumen335 in theimplant actuation shaft334, andlumens150 in anend cap148 at thedistal end102 of theimplant100. In addition, the illustrated embodiments can be deployed in a proximal or distal direction, as discussed in greater detail below. Any of the features of embodiments illustrated inFIGS. 17 and 18 can be used in conjunction with each other, along with combinations of embodiments illustrated inFIGS. 19-21, or any other embodiments of the invention described herein.
• Referring toFIGS. 18A-18C, an embodiment of acatheter system300 has animplant actuation shaft334 which extends through thecatheter body302 and can extend through theimplant100 to touch the stoppingsurface126 at thedistal end102 of theimplant100. When theimplant actuation shaft334 provides a sufficient load in the distal direction against the stoppingsurface126 while a proximally-directed load is applied to theproximal end104 of theimplant100, theimplant100 can be held in sufficient tension to overcome the normal shape-memory bias toward a radially-expanded configuration for theimplant100, resulting in animplant100 with a radially-reduced configuration. The embodiment of thesystem50 illustrated inFIGS. 17A-17C depicts steps where theimplant actuation shaft334 is retracted proximally into thecatheter body302 and theimplant100 tends to return to its radially-expanded configuration as of itsdistal end102 moving proximally.
• The embodiment of thesystem50 illustrated inFIGS. 18A-18C depict steps where the concentric tensile loading on theproximal end104 of theimplant100 is reduced by allowing theproximal end104 of theimplant100 to move distally such that theimplant100 as a whole tends to return to its radially-expanded configuration by moving distally. The retraction of theimplant actuation shaft334 and reduction in concentric tensile loading on theproximal end104 of theimplant100 may occur independently, simultaneously, or incrementally to control the relative axial placement of theimplant100 in aLAA10.
• Thelumen335 in theimplant actuation shaft334 may contain radiopaque or contrast materials injected into thecatheter system300 through ports in thedeployment handle400, as described above and below. The exit point for contrast to exit thelumen335 may be at the distal tip of theimplant actuation shaft334 or along any exit port (not illustrated) along theimplant actuation shaft334. One embodiment of alumen335 is similar to thelumen350 of thetubular torque rod340 described above and illustrated inFIG. 14. Thelumen335 preferably allows visualization dye to flow through thelumen335 of theimplant actuation shaft334 and through theimplant frame101 or through at least onelumen150 of theimplant end cap148, and into the LAA10 (not illustrated here). Such usage of visualization dye is useful for clinical diagnosis and testing of the position of theimplant100 within theLAA10 or other body openings.
• FIGS. 19A-19C and20A-20C illustrate additional embodiments of adisconnect mount236 havingflex fingers238, a correspondingdisconnect mount interface180, and acatheter body302, which is at least partially contained within alock tube234. Thedisconnect mount236 provides concentric loading to theimplant100 without imparting rotational loads to theimplant100. Theflex fingers238 can be biased to extend radially outwardly or inwardly, as discussed above. In one embodiment, theflex fingers238 are biased inwardly. Theflex fingers238 can also include a proximalinclined surface242 at the transition from theflex finger238 to the protrudingportion240. As illustrated, the embodieddisconnect mount interface180 uses afinger interface182 in the form of slots or windows in a wall of aproximal end104 of theimplant100. Referring to embodiments inFIGS. 19B and 20B, after theimplant100 is deployed and radially expanded in a LAA10 (not illustrated here), anchors118 (not illustrated here) on theimplant frame101 secure theimplant100 within theLAA10. The interface between theimplant100 and thedisconnect mount236 provides concentric loading to theimplant100. In one embodiment the concentric loading is concentric tension.
• Thelock tube234 can be withdrawn proximally away from contact with theflex fingers238, allowing theflex fingers238 to deflect outwardly. When theflex fingers238 are moved proximally with respect to theimplant100, such as when thecatheter system300 is withdrawn proximally away from the expandedimplant100 in theLAA10, the inside edge of thedisconnect mount interface180 can press onto the proximalinclined surface242, which provides a radially outward force to theflex fingers238. The radially outward force causes theflex fingers238 or at least a distal portion of theflex fingers238 to move radially outwardly. Once theflex fingers238 are sufficiently radially deflected, theimplant100 is disconnected from thedelivery system50 without imparting any or any substantial moment arms or bending bias with respect to theimplant100. As depicted inFIGS. 19C and 20C, once theimplant100 is detached, theflex fingers238 will bias toward their natural state (inward bias is illustrated in solid lines and outward bias is illustrated in dotted lines).
• In another embodiment illustrated inFIGS. 19A-19C and20A-20C, theflex fingers238 are biased outwardly. Referring to embodiments inFIGS. 19B and 20B, after theimplant100 is deployed and radially expanded in a LAA, anchors (not illustrated) on theimplant frame101 secure theimplant100 within the LAA. The interface between theimplant100 and thedisconnect mount236 provides concentric loading to theimplant100. In one embodiment the concentric loading is concentric tension. At this point, thelock tube234 can be withdrawn proximally away from contact with theflex fingers238, allowing theflex fingers238 to deflect outwardly in their natural state.
• Once theflex fingers238 are sufficiently radially deflected, theimplant100 is disconnected from thedelivery system50 without imparting any or any substantial moment arms or bending bias with respect to theimplant100. As depicted inFIGS. 19C and 20C, once theimplant100 is detached, theflex fingers238 will bias toward their natural state (inward bias is illustrated in solid lines and outward bias is illustrated in dotted lines). When theflex fingers238 are biased outwardly, thelock tube334 can be slideably engaged over the flex fingers238 (not illustrated inFIG. 19C) or over a finger pivot axis239 (as illustrated inFIG. 20C) in order to deflect theflex fingers238 inwardly to facilitate extraction of the implant delivery system and/or catheter system from the body.
• FIGS. 20A-20C illustrate an embodiment of adisconnect mount236 withflex fingers238, a correspondingdisconnect mount interface180, and acatheter body302 at least partially contained within alock tube234, as described above. The illustrated embodiment ofFIGS. 20A-20C includes alock tube234 that only partially surrounds theflex fingers238 of thedisconnect mount236. In addition, afinger pivot axis239 located proximally to theflex fingers238 defines the axis about which the flex fingers rotate. In leaving thelock tube234 proximal to theflex fingers238 and at least a portion of thedisconnect mount236, thelock tube234 can maintain a relativelysmaller lock tube234 diameter than would be the case if thelock tube234 had to enclose the entire diameter of thedisconnect mount236, resulting in easier insertion of thecatheter system300 into the body. Thefinger pivot axis239 can be formed as a crease in anextended flex finger238 located proximally to an increase indisconnect mount236 diameter, or as a physical hinge or pin in a linkage mechanism to create thedisconnect mount236.
• All of the foregoing embodiments, including those ofFIGS. 17A-20C could include an implant that has a single or dual guide tubes, as discussed above. For example, in the embodiments ofFIGS. 17A-20C, theimplant100 could include a distal, outer guide tube attached to thedistal end102 of theimplant100, and a concentric, proximal, inner guide tube attached to theproximal end104 of theimplant100.
• FIGS. 21A-21C illustrate another embodiment of a distal portion of animplant delivery system50, which includes animplant100, an implant release and recapturemechanism200, acatheter system300, and a deployment handle400 (not illustrated). The illustrated embodiments include animplant100 that has aproximal end104, adistal end102 with a stoppingsurface126, aframe101, tissue anchors118, and adisconnect mount interface180 on theproximal end104 of theimplant100. Thedisconnect mount interface180 has afinger interface182 which interacts with aflexible finger238 on adisconnect mount236 on thecatheter system300 to apply releasable concentric loads in a manner similar to the embodiments described above. Embodiments of thefinger interface182 may be in the form of a protruding finger, an interlocking feature, a groove, a slot, a window, or other similar features for releasably holding, engaging and/or coupling a disconnect mountflexible finger238. Thedistal end102 of theimplant100 may also have anend cap148 with zero ormore lumens150. Various embodiments and combinations of embodiments of theimplant100 may be used, including but not limited to single or multiple guide tube configurations, as described above.
• As illustrated,FIGS. 21A-21C show an implant with a multiple guide tube configuration as is described above relating toFIGS. 13A and 13B. Theimplant100 has anouter guide tube162 which is also adistal guide tube130, and aninner guide tube164 which is also aproximal guide tube160.
• In some embodiments thecatheter system300 has adisconnect mount236 provided on thedistal end310 of adelivery catheter302. Thedisconnect mount236 may be any mechanical mount that releases one body from another without creating any or any substantial moment arms or bending bias. Thedisconnect mount236 may provide releasable concentric tension or concentric loading to animplant100. The loading imparted by thedisconnect mount236 to theimplant100 may be in a proximal or distal direction. For example, in some embodiments, the concentric loading applies tension in a proximal direction with respect to the implant, and in other embodiments, the concentric loading applies a pushing force in a distal direction.
• Distal loading may be imparted to advance theentire catheter system300 andimplant100 distally into a heart. Proximal loading may be used in conjunction with a distally-loading shaft that works with thedisconnect mount236 in placing animplant100 in tension in order to radially reduce a diameter of theimplant100. In one embodiment, adisconnect mount236 includes an annular ring that is controlled to switch between an expanded and a reduced diameter configuration. In one embodiment, thedisconnect mount236 may act like a stent, and radially expand when activated.
• In other embodiments, a disconnect mount includes two, three, four, or a plurality of actuating fingers, such as ten or more actuating fingers. As illustrated, thedisconnect mount236 has at least twoflexible fingers238 which may engage within recesses, windows, or corresponding structure in adisconnect mount interface180 on aproximal end104 of animplant100. Thedisconnect mount interface180 may have afinger interface182 that is specially adapted to releasably hold adisconnect mount236flexible finger238 in place.
• Thedisconnect mount236 can be created from rod stock using a combination Swiss screw machine and Electrical Discharge Machining (EDM) operation to fashion at least two substantiallysymmetric flex fingers238 with protrudingportions240. Thedisconnect mount interface180 may have afinger interface182 that is specially adapted to releasably hold adisconnect mount236flexible finger238 in place.
• The protrudingportions240 of theflex fingers238 are captured within cutouts, recesses, or windows located on thefinger interface182 of thedisconnect mount interface180, which is located on aproximal portion104 of theimplantable device100. For example, the implant'sfinger interface182 can include cutouts that releasably engageflex fingers238 of thedelivery system50.
• In some embodiments, thecatheter system300 has animplant actuation shaft334 which extends through thecatheter body302 and can extend through theimplant100 to touch the stoppingsurface126 at thedistal end102 of theimplant100. When theimplant actuation shaft334 provides a sufficient load in the distal direction against the stoppingsurface126 while a tensile load in a proximal direction is applied to theproximal end104 of theimplant100, theimplant100 can be held in a radially-reduced configuration. This overcomes the shape-memory bias toward a radially-expanded configuration for theimplant100.
• When theimplant actuation shaft334 is retracted proximally into thecatheter body302, theimplant100 tends to return to its radially-expanded configuration by moving proximally. When the tensile loading on theproximal end104 of theimplant100 is reduced by allowing theproximal end104 of the implant to move distally, theimplant100 tends to return to its radially-expanded configuration by moving distally (as is depicted in the embodiment illustrated inFIGS. 21A-21C). The retraction of theimplant actuation shaft334 and reduction in tensile loading on theproximal end104 of theimplant100 may occur independently, simultaneously, or incrementally to control the relative axial placement of theimplant100 in aLAA10.
• In some embodiments, a lumen335 (not illustrated) in theimplant actuation shaft334 may contain radiopaque or contrast materials injected into thecatheter system300 through ports in thedeployment handle400, as described above and below. In some embodiments, theimplant actuation shaft334 may be constructed of a flexible material, such as apuzzle lock profile600, as described relating toFIG. 25A below.
• In the illustrated embodiment ofFIGS. 21A-21C, theimplant actuation shaft334 includes a threadedportion336. In this embodiment, any rotational loads imparted due to the threadable engagement between thehub236 and theimplant actuation shaft334 are transferred within the implant release and recapturemechanism200 on the side with thecatheter system300, thereby avoiding rotational loading of theimplant100 within theLAA10.
• The threadedportion336 of theimplant actuation shaft334 may be manufactured by a lathing or machining process from the same material as theimplant actuation shaft334, or threadedportion336 may be a separate piece that is bonded, welded, soldered, braided, or otherwise attached to a portion of theimplant actuation shaft334. In the illustrated embodiment, rotating theimplant actuation shaft334 causes it to advance longitudinally. For example, the threadedportion336 engages a threadedportion246 of adisconnect mount236 in a screw-like manner. Rotating theimplant actuation shaft334 when the threadedportions336,246 are engaged causes theshaft334 to advance proximally or distally, depending upon the direction of shaft rotation. When the threads are disengaged, theactuation shaft334 can slide with respect to theimplant100.
• The illustrated embodiment can provide anywhere in the range of 0%-100% of the collapse of theimplant100 by axially sliding aimplant actuation shaft334. In some embodiments, theimplant actuation shaft334 causes 25%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 90%, or 95% of the collapse or expansion of theimplant100, and can lock the implant in a partially-expanded or partially-reduced state. This provides the advantage of allowing the clinician to verify proper position and orientation of theimplant100 in small steps as theimplant100 is deployed within the patient's body.
• Expansion of theimplant100 occurs while the threadedportion336 of theimplant actuation shaft334 is engaged with the threadedportion246 thedisconnect mount236. While the threadedportion336 of theimplant actuation shaft334 is engaged with the threadedportion246 thedisconnect mount236, theimplant actuation shaft334 is essentially locked in place unless sufficient torque is provided to rotate the two threadedportions336 and246 with respect to one another. This allows theimplant100 to be held or maintained in a fully or partially radially-reduced configuration.
• While theflex fingers238 hold theproximal end104 of theimplant100 with concentric tensile force, animplant actuation shaft334 extends through theimplant100 and pushes distally against thedistal end102 of theimplant100. As described above, theimplant100 can be made self-expanding, so that when the distal pushing force exerted by theimplant actuation shaft334 or the concentric proximal pulling (or holding) force applied by theflex fingers238 is removed or reduced theimplant100 automatically radially expands to a predetermined size and shape. Theimplant100 can be maintained in its reduced diameter configuration by holding theproximal end104 of theimplant100 with theflex fingers238 and pushing against thedistal end102 of theimplant100 with theimplant actuation shaft334. In this configuration, relative movement between the innerimplant actuation shaft334 and the concentric,outer flex fingers238 controls implant100 expansion and collapse.
• In some embodiments, theflex fingers238 are biased to extend either radially inwardly or radially outwardly. In embodiments where theflex fingers238 are biased to extend radially inwardly, theflex fingers238 engage adisconnect mount interface180 to lock animplant100 to theimplant delivery system50 when a structure prevents theflex fingers238 from extending radially inwardly.
• In one embodiment, as illustrated inFIGS. 21A-21C, theflex fingers238 may be held in place with adisconnect mount interface180 of theimplant100 by the presence of animplant actuation shaft334 which extends through theimplant100 and prevents theflex fingers238 from extending radially inwardly. When theimplant actuation shaft334 is withdrawn proximally toward thecatheter system300 past thedisconnect mount236, the open space created by the removal of theimplant actuation shaft334 leaves room for theflex fingers238 to extend radially inwardly under its bias. This radial movement of theflex fingers238 releases thedisconnect mount236 from thedisconnect mount interface180, thereby releasing theimplant100 from theimplant delivery system50.
• In embodiments where theflex fingers238 are biased to extend radially outwardly, theflex fingers238 engage adisconnect mount interface180 to lock animplant100 to theimplant delivery system50 in its natural state. When a structure or a load causes theflex fingers238 to extend radially inwardly the radial movement of theflex fingers238 releases thedisconnect mount236 from thedisconnect mount interface180, thereby releasing theimplant100 from theimplant delivery system50 with significantly reduced or non-existent bending bias and rotational bias.
• In some embodiments of animplant delivery system50, markers204 (not illustrated) may be placed in locations visible by fluoroscopic or other means known in the art of visualizing the manipulation or implantation of devices within a body. Themarkers204, which can be radiopaque in nature, can be placed on any surfaces to assist in deployment or recapture of animplant100, as is described above for the embodiment of amarker360 as shown inFIG. 14, which advantageously assists in locating the position of adistal end344 of an axiallymoveable core342.
• In various embodiments, amarker204 comprises a radiopaque band, dot, coating, or material that is attached to adisconnect mount236, adistal end104 of animplant100, and a portion of animplant actuation shaft334.Marker204 preferably is made from a material readily identified after insertion into a patient's body by using visualization techniques that are well known to those of skill in the art. In one embodiment, themarker204 is made from gold, or tungsten, or any such suitable material, as is well known to those of skill in the art. In another embodiment,marker204 is welded, soldered, or glued onto a structure for marking. In one embodiment, the use ofmarkers204 segments is useful to discern the radial orientation of theimplant100 within the body.
• Referring once again toFIGS. 21A-21C, flexfingers238 can be biased to extend radially outwardly or inwardly, as discussed above. In one embodiment, theflex fingers238 are biased outwardly. Theflex fingers238 can also include a proximalinclined surface242 at the transition from theflex finger238 to the protrudingportion240. As illustrated, the embodieddisconnect mount interface180 uses afinger interface182 in the form of slots or windows in a wall of aproximal end104 of theimplant100.
• Referring to embodiments inFIG. 21B, after theimplant100 is deployed and radially expanded in a LAA10 (not illustrated here), anchors118 on theimplant frame101 secure theimplant100 within theLAA10. As depicted inFIG. 21C, theimplant actuation shaft334 can be withdrawn proximally away from contact with theflex fingers238, allowing theflex fingers238 to deflect inwardly. When theflex fingers238 are moved proximally with respect to theimplant100, such as when thecatheter system300 is withdrawn proximally away from the expandedimplant100 in theLAA10, the inside edge of thedisconnect mount interface180 can press onto the proximal inclined surface242 (not shown), which provides a radially inward force to theflex fingers238.
• The radially inward force causes theflex fingers238 or at least a distal portion of theflex fingers238 to move radially inwardly. Once theflex fingers238 are sufficiently radially deflected, theimplant100 is disconnected from thedelivery system50 without imparting any or any substantial moment arms or bending bias with respect to theimplant100. As depicted inFIG. 21C, once theimplant100 is detached, theflex fingers238 will bias toward their natural state (inward bias is illustrated in solid lines and outward bias is illustrated in dotted lines).
• In another embodiment illustrated inFIGS. 21A-21C, theflex fingers238 are biased inwardly. Referring to embodiments inFIG. 21B, after theimplant100 is deployed and radially expanded in a LAA10 (not illustrated here), anchors118 on theimplant frame101 secure theimplant100 within theLAA10. As depicted inFIG. 21C, theimplant actuation shaft334 can be withdrawn proximally away from contact with theflex fingers238, allowing theflex fingers238 to deflect inwardly in their natural state. Once theflex fingers238 are sufficiently radially deflected, theimplant100 is disconnected from thedelivery system50 without imparting any moment arms or bending bias with respect to theimplant100. As depicted inFIG. 21C, once theimplant100 is detached, theflex fingers238 will bias toward their natural state (inward bias is illustrated in solid lines and outward bias is illustrated in dotted lines). When theflex fingers238 are biased inwardly, theimplant actuation shaft334 can be slideably engaged under theflex fingers238 in order to deflect theflex fingers238 outwardly.
• As illustrated in FIGS.21A-C, some embodiments include aflexible sock392 positioned between thecatheter body302 and thedisconnect mount236. Thesock392 is discussed in greater detail below. In some embodiments, acatheter body302 may be directly mounted to adisconnect mount236.
• In the illustrated embodiments described herein, an implant deployment system generally includes an implant coupled to a catheter with a release mechanism. The system also generally includes a mechanism to expand or contract the diameter of the implant. Although many of the embodiments describe the release mechanism coupled to the distal end of the catheter and the proximal end of the implant, it should be well understood by those of skill in the art that in other embodiments, the release mechanism is coupled to the distal end of the implant.
• In addition, when the release mechanism is coupled to the proximal end of the implant, the implant is expanded by either moving the distal end of the implant proximally, by moving the proximal end of the implant distally, or by moving both ends towards the center of the implant. In many cases, the proximal end of the implant is held in place with respect to the patient's LAA and the distal end of the implant is allowed to move proximally under the self-expanding forces of the implant. However, in some situations, for example when treating patients that have a very short LAA, it may be desirable to perform a different procedure. For example, in such situations the clinician may desire to hold the distal end of the implant in place with respect to the patient's LAA while moving the proximal end of the implant distally; otherwise, the proximal end of the implant could wind up positioned within the patient's left atrium.
• In some embodiments, the implant is expanded “in a distal direction” as just described by coupling the release mechanism to the distal end of the implant and then releasing tension from the implant's proximal end. Once the implant is radially expanded, the implant is released and the catheter is removed. For example, in one embodiment, the catheter and/or release mechanism extends through the implant's proximal end and its body to contact a portion near the distal end of the implant from within the implant.
• The term “in a distal direction” refers to the steps of keeping the distal end of the implant in a relatively, substantially fixed position with respect to the deployment site while advancing the proximal end of the implant distally. Similarly, the term “in a proximal direction” refers to the steps of holding the proximal end of the implant in a relatively, substantially fixed position with respect to the deployment site while advancing the distal end of the implant proximally.
• Therefore, the deployment systems can be configured to deploy in a proximal or a distal direction (or both). In addition, for any deployment direction configuration, the deployment systems can be further configured such that the release mechanism couples to either the proximal or distal end of the implant.
• Referring toFIGS. 21D and 21E, in one embodiment thedeployment system50 is configured to deploy theimplant100 in a distal direction, and therelease mechanism200 is coupled to theproximal end104 of theimplant100. A shaft, such as an axiallymoveable core304, extends through theimplant100 and contacts thedistal end102 of theimplant100. Thecore304 includes aninner core305 and anouter core307, which are coaxially aligned and can be longitudinally moved with respect to each other.
• Theouter core307 includes two longitudinally spaced locking mechanisms. Thefirst locking mechanism309 is configured to engage and secure theouter core307 to amating portion313 of thedistal end310 of thecatheter302. Thesecond locking mechanism311 is configured to engage and secure theouter core307 to amating portion345 of theimplant100. In one embodiment, the lockingmechanisms309 and311 include two radially offsetcams347 and349 configured to engagemating surface slots351 and353, respectively, extending annularly within correspondingcatheter mating portion313 andimplant mating portion345, respectively.
• Initially thecams347 and349 of theouter core307 engage and are locked within both thecatheter mating portion313 andimplant mating portion345, respectively. In this configuration, thecatheter302,outer core307, andimplant100 are fixed with respect to each other, and can be advanced together through a deployment sheath, such as a transseptal sheath (not illustrated here) or other retractable sheath.
• Theinner core305 is extended to contact and push against thedistal end102 of theimplant100. Pushing on thedistal surface126 at thedistal end102 with theinner core305 while holding theproximal end104 in tension with theouter core307 maintains theimplant100 in a reduced-diameter configuration. The diameter-reducedimplant100 is advanced through the patient's vasculature to a desired deployment site. At the deployment site, the implant's100distal end102 is positioned under visualization at a desired location.
• Theouter core307 is rotated with respect to thecatheter302 to cause thecatheter cam347 to align with anexit slot355 in thecatheter mating portion313. Because thecatheter cam347 andimplant cam349 are offset from one another, alignment of thefirst cam347 with the catheter mating portion's313exit slot355 does not cause thesecond cam349 to be aligned with the implant mating portion's345exit slot357. For example, in some embodiments, thecams347 and349 are offset by about 15, 45, or 90 degrees from each other.
• Theouter core307 is then advanced distally with respect to thecatheter302. Theouter core307 is now axially decoupled from thecatheter302, but still coupled to the proximal end of theimplant100 via the second cam349-mating portion345 engagement. As theouter core307 is moved distally, theproximal end104 of theimplant100 is also advanced distally. This causes theimplant100 to expand in a distal direction, e.g., while maintaining thedistal end102 of theimplant100 in a substantially fixed position with respect to the deployment site (e.g., theLAA10, not pictured here). In addition, as theouter core307 is advanced distally with respect to thecatheter302, theouter core307 is also advanced distally with respect to theinner core305. This prevents distal advancement of theouter core307 from pushing theimplant100 deeper into theLAA10, or out of the desired deployment location.
• When theimplant100 is fully expanded theouter core307 is disengaged, or decoupled from theimplant100 by rotating thesecond cam349 with respect to theimplant100. When theimplant cam349, or a cam tab, is aligned with anexit slot357 in theimplant mating portion345, theouter core307 can be retracted proximally with respect to theimplant100 without substantially affecting the implant's100 deployment location or orientation. At this point theouter core307 is decoupled from both thecatheter302 andimplant100, and may withdrawn with thecatheter302 andinner core305 from the patient's vasculature.
• In some embodiments the inner305 andouter shafts307 are made from flexible hypotube. In other embodiments, the lockingmechanisms309 and311 are sometimes referred to as an implant key or tip or as a catheter key or tip. Themating portion313 of thecatheter302 is sometimes referred to as the locking tip.
• FIG. 21F illustrates another flexible implant delivery system in accordance with yet another embodiment of the invention. Thedelivery system50 includes animplantable device100 and arelease mechanism200. The configuration described with respect toFIG. 21F can be utilized and/or incorporated into any of the other embodiments described herein.
• Theimplantable device100 is similar to all of the other implantable devices described herein. Theimplantable device100 is configured to expand from a radially reduced configuration to a radially expanded configuration. For example, in some embodiments, theimplantable device100 is self expandable. Theimplantable device100 includes a plurality of struts that extend from the implant'sproximal end104 to itsdistal end102. A window, notch, hole, or port, in the implant'sproximal end104 is configured to releasably engage therelease mechanism200.
• Therelease mechanism200 includes adrive shaft363, which is coupled at its distal end to the proximal end of a flexible recaptureshaft365. In one embodiment, thedrive shaft363 is made from 0.025″ diameter tubing. In another embodiment, the flexible recaptureshaft365 is made from 0.042″ outside diameter by 0.027″ inside diameter tubing. The distal end of the flexible recaptureshaft365 is coupled to a threadedadapter337. In one embodiment, the recaptureshaft365 andadapter337 are coupled with across pin338. For example, a 0.025″cross pin338 is sometimes used. The distal end of the threadedadapter337 is coupled to a second flexible recaptureshaft367. In some embodiments, a single flexible recaptureshaft365 is used, which extends through the threadedadapter337. The threadedadapter337 includes a threadedportion339 with threads along at least a portion of its outside surface.
• Thedriver363, flexible recaptureshafts365 and367, and threadedadapter337 are disposed within anouter shaft assembly369. Theouter shaft assembly369 includes abraided shaft371 that is coupled at its distal end to aflexible torque shaft375. In one embodiment, thebraided shaft371 is thebraided sock392 described above. In another embodiment, thebraided shaft371 has dimensions of 0.084″ OD×0.055″ ID. In one embodiment, theflexible torque shaft375 is thebraided sock392 described above. In one embodiment, theflexible torque shaft375 has dimension of 0.083″ OD×0.072″ ID. The distal end of theflexible torque shaft375 is coupled to apush screw disconnect377, which in some embodiments is thedisconnect mount236 described in greater detail herein.
• Thepush screw disconnect377 has distally extendingfingers379 that have a larger diameter at their distal ends. Thepush screw disconnect377 also includes a threaded insidesurface381 configured to engage the threadedportion339 of the threadedadapter337. The distal ends of thefingers379 are configured to engage thewindow182 in theimplant100 and to hold theimplant100 with respect to thebraided shaft371 andflexible torque shaft375. However, in one embodiment thefingers379 are biased to flex inward to release theimplant100. Therefore, aninner core assembly361, comprising thedriver363, flexible recaptureshafts365 and367, and threadedadapter337 are used to interfere with inward movement of thefingers379, and to hold thefingers379 outward such that they continue to radially, coaxially engage theimplant100.
• To release theimplant100, theinner core assembly361 is rotated with respect to thepush screw disconnect377. Thecore assembly361 is rotated until it no longer engages thepush screw disconnect377, at which point it is retracted proximally with respect to theouter shaft assembly369. Once theinner core assembly361 is retracted, thefingers379 move radially and concentrically inward to their biased position, thereby releasing theimplant100. Theimplant100 is released by removing the concentric radial force provided by theouter core assembly369. Releasing theimplant100 in this manner does not cause theimplant100 to substantially jump, move, or otherwise change its orientation with respect to thedelivery system50.
• 3. Deployment Catheter and Deployment Handle
• Referring again toFIG. 2, there is illustrated a block diagram representing animplant delivery system50 suitable for use with any and all of the embodiments discussed herein. Theimplant delivery system50 includes animplant100, an implant release and recapturemechanism200, acatheter system300 and adeployment handle400.FIG. 2A illustrates one embodiment of animplant delivery system50 comprising particular examples of animplant100, an implant release and recapturemechanism200, acatheter system300 and adeployment handle400.
• Referring again toFIG. 11, there is schematically illustrated a further embodiment of the present invention. An adjustableimplant delivery system50 comprises generally acatheter302 for placing adetachable implant100 within a body cavity or lumen, as has been discussed. Thecatheter302 comprises an elongate flexibletubular body306, extending between aproximal end308 and adistal end310. The catheter is shown in highly schematic form, for the purpose of illustrating the functional aspects thereof. The catheter body will have a sufficient length and diameter to permit percutaneous entry into the vascular system, and transluminal advancement through the vascular system to the desired deployment site. For example, in an embodiment intended for access at the femoral vein and deployment within the left atrial appendage, thecatheter302 will have a length within the range of from about 50 cm to about 150 cm, and a diameter of generally no more than about 15 French. Further dimensions and physical characteristics of catheters for navigation to particular sites within the body are well understood in the art and will not be further described herein.
• Thetubular body306 is further provided with ahandle402 generally on theproximal end308 of thecatheter302. Thehandle402 permits manipulation of the various aspects of theimplant delivery system50, as will be discussed below. Handle402 may be manufactured in any of a variety of ways, typically by injection molding or otherwise forming a handpiece for single-hand operation, using materials and construction techniques well known in the medical device arts.
• In the embodiment illustrated inFIG. 14, or any other of the deployment and/or removal catheters described herein, thedistal end310 of thetubular body306 may be provided with a zone or point of enhanced lateral flexibility (indicated by the sectional lines on thetube306 at the distal end310). This may be desirable in order allow the implant to seat in the optimal orientation within the leftatrial appendage10, and not be restrained by a lack of flexibility in thetubular body306. This may be accomplished in any of a variety of ways, such as providing the distal most one or two or three centimeters or more of thetubular body306 with a spring coil configuration. In this manner, the distal end of thetubular body306 will be sufficiently flexible to allow theimplant100 to properly seat within theLAA10. This distal flex zone on thetubular body306 may be provided in any of a variety of ways, such as by cutting a spiral slot in the distal end of thetubular body306 using laser cutting or other cutting techniques. The components within thetubular body306 such astorque rod340 may similarly be provided with a zone of enhanced flexibility in the distal region of thetubular body306.
• FIG. 22 (which is similar toFIG. 2A) illustrates one embodiment of animplant delivery system50 comprising an operablyconnected implant100, an implant release and recapturemechanism200, acatheter system300 and adeployment handle400. As shown inFIG. 22, the embodiedcatheter system300 comprises a peel-awaysheath314, a recapturesheath522, adeployment catheter302, aloading collar323, amulti-lumen shaft326, and an axiallymoveable core304, each described further below. Thesystem50 may also include a transseptal sheath520 (not illustrated here) that is substantially coaxial and external to the other catheters. In some embodiments, the transseptal sheath may be one of the other catheters. The deployment handle400 comprises ahandle402, acontrol knob408, arelease knob410, aproximal injection port412 and adistal injection port414. Injection ports546,548, as shown inFIG. 22, preferably are provided in thedelivery system50 to allow contrast injection proximally and distally of theimplant100 to facilitate in-vivo assessment of the positioning and seal quality of theimplant100.
• Referring again toFIG. 22, illustrated is an embodiment of animplant delivery system50. When an embodiment of thedelivery system50 is assembled, a recapturesheath522 is loaded over thedeployment catheter302, distal to thehandle402. The recapturesheath522 is designed to allow recapture of theimplant100 prior to its detachment or final release, such as described with respect toretrieval catheter502 above. Recapture petals or flares510 may be provided on thedistal end506 of the recapturesheath522 to cover theanchors118 of theimplant100 during retrieval into thetransseptal sheath520, as described above with respect toFIGS. 15C-15E, and further below. A Touhy-Borst adapter orvalve530 may be attached to theproximal end524 of the recapturesheath522. The recapturesheath522 comprises aradiopaque marker528 on itsdistal end526 near the recapture flares510. The recapturesheath522 comprises a recapturesheath injection port529 for delivering fluid proximal theimplant100.
• An embodiment of the peel-awaysheath314 is provided over a portion of the recapturesheath522, between Touhy-Borst valve530 and recaptureflares510. The peel-awaysheath314 is used to introduce acatheter302 into a transseptal sheath520 (not illustrated). As shown inFIG. 22, an embodiment of the peel-awaysheath314 comprises alocking collar315, a peel-awaysection316, and a reinforcedsection317. The locking collar can be unlocked relative to peel-awaysection316, and may include a threadedhub318 that releasably engagestabs319 of the peel-awaysection316.
• An embodiment of theloading collar323 is located over a portion of the peel-awaysheath314 and a portion of the recapturesheath522 with its proximal end being located over the peel-awaysheath314 at its distal end loaded over recapturesheath522. Theloading collar323 can accommodate loading acollapsed implant100 into the peel-awaysheath314 as described below. As shown inFIGS. 17, an embodiment of theloading collar323 comprises afirst end portion324 adapted to receive and extend over acollapsed implant100, and asecond end portion325 configured to guide thecollapsed implant100 into the peel-awaysheath314. Theloading collar323 may be made of stainless steel.
• In order to assemble an embodiment of thedelivery system50, the axiallymovable core304 andcontrol line312 are fed into themulti-lumen shaft326 of thedeployment catheter302. Themulti-lumen shaft326 is then coupled with components of thedeployment handle400 and theinjection port components412,414. The peel-awaysheath314 and theloading collar323 are slid onto the recapturesheath522, and the recapturesheath522 is slid onto thedeployment catheter302. Theimplant100 is then loaded on an end of the axiallymovable core304 and coupled with thecontrol line312. In one embodiment, theimplant100 is loaded on an end of the axiallymovable core304 by screwing the axiallymovable core304 into the threadedportion246 of a disconnect mount236 (not illustrated here). Thecontrol knob408 and outer casing of thedeployment handle400 are then coupled with the system.
• In an embodiment of thedeployment catheter system300, acatheter302 is used in connection with a transseptal sheath520 (not illustrated here, but seeFIG. 25) to advance theimplant100 for deployment in a patient. Thetransseptal sheath520 is a tubular device that in one embodiment can be advanced over a guidewire (not shown) for accessing theLAA10 of a patient'sheart5. In some embodiments thetransseptal sheath520 may also serve as one of the other disclosed catheters described herein.Transseptal sheath520 in some embodiments has a permanent bend or a controllable bend. A hemostasis valve (not illustrated) is provided at the proximal end of transseptal sheath. A fluid injection port is also provided at the proximal end to delivery fluid such as contrast media through the transseptal sheath. Systems and methods for implanting thedevice100 in theLAA10 are described further below.
• One embodiment of amulti-lumen shaft326 may comprise a four-lumen shaft as illustrated inFIG. 22A. Themulti-lumen shaft326 comprises acore lumen328 for holding an axiallymoveable core304, acontrol line lumen330 and twoproximal injection lumens332 in communication withproximal injection port412. In some embodiments, the axiallymoveable core304 is theimplant activation shaft334, discussed in greater detail above.
• An axiallymoveable core304 preferably extends from the deployment handle400 through thecore lumen328 of thecatheter302 and couples theimplant100 of thedelivery system50. A control line312 (referred to previously as a pull wire312) preferably extends through thecontrol line lumen330 and preferably couples aproximal hub104 of theimplant100 to the deploymenthandle control knob408, allowing forimplant100 expansion and collapse. Thecontrol line312 preferably extends around a portion of the axiallymovable core304 near theproximal hub104 of theimplant100, and is coupled to theimplant100 bycrosspin146, as described above.
• Referring toFIG. 23, one embodiment of thecatheter system300 preferably comprises aflexible catheter section362 at its distal end, which in some embodiments is a spiral cut tubular section housed in apolymer sleeve366. Theflexible catheter section362 may be coupled to a distal end of amulti-lumen shaft326.
• As shown inFIG. 24 and24A, one embodiment of the axiallymoveable core304 preferably includes a hollowproximal shaft368 and a hollowdistal shaft370 with a flexiblehollow core section372 therebetween, all co-axially aligned and connected. In one embodiment, the proximal end of thedistal shaft370 is attached to the distal end of theflexible core section372, and the proximal end of theflexible core section372 is attached to the distal end of theproximal shaft368. In some embodiments, theflexible core section372 has aspring coil section374 housed in apolymer sleeve376, thespring coil section374 preferably coupled with theshafts368 and370 on first and second ends378 and380, respectively. In another embodiment aninjection tube373 with a lumen is provided, through which contrast fluid may be ejected out of the distal end of theimplant actuation shaft334 and into theimplant100. This is useful in assessing implant seal against the ostium or inside wall of the left atrial appendage. Theinjection tube373 has been prototyped in low durometer (flexible) PEBAX and provides a soft segment transition over the distal-most 10 cm of thedelivery catheter302 or within aflexible core section372. Theinjection tube373 may be connected to other tubes such as a lock tube234 (as discussed relating toFIGS. 17-20) but is not used to torque or apply rotational forces to the tube.
• The axiallymoveable core304 preferably is disposed within thedeployment catheter302 such that theflexible core section372 may be linearly co-located with theflexible catheter section362 at adistal portion382 of thecatheter system300 during appropriate times during a procedure, as shown inFIG. 23. When theflexible core section372 is aligned and linearly co-located with theflexible catheter section362, the sections preferably cooperate to form a delivery systemflexible segment384. As shown in FIGS.22 and23, the delivery systemflexible segment384 preferably is located toward adistal portion382 of thecatheter system300.
• In one embodiment, shown inFIG. 24, thedistal shaft370,flexible core section372, andproximal shaft368 are attached by welding.Small windows386 may be provided to allow welding materials to flow between the shafts564,576 and578 and provide stronger bonding therebetween. In another embodiment, solder, glue, or press-fitting is used to attach shafts564,576, and578 to one another, as is well known to those of skill in the art. In another embodiment, the shafts564,576 and578 are formed from a single tube, for example, a laser-cut tube. In other embodiments, more than one tube may be used to form each of the shafts564,576 and578. For example,FIG. 24 illustratesproximal shaft368 comprising two tubes connected by welding such as described above.
• Referring again toFIG. 24A, distal contrast media preferably can be injected through alumen388 in the shafts576 and578 for determining the placement of theimplant100. Thislumen388 may be in fluid communication withdistal injection port414, shown inFIG. 22. Thedistal shaft370 preferably comprises amating surface390 and aradiopaque marker360, such as described above. In one embodiment, themating surface390 is a threaded surface. Thedistal shaft370 preferably is releasably coupled to theimplant100, such as described above.
• FIG. 25 illustrates an embodiment of apuzzle lock profile600 that may be used with any of the embodiments of theimplant delivery system50 described herein in order to increase flexibility. As discussed above, some of the embodiments deliver animplant100 to theLAA10 in an orientation and under a loading condition that approximates the final released state of theimplant100. This reduces bias and moment arms that can cause theimplant100 to deform, move, jump, or change orientation when theimplant100 is released from theimplant delivery system50. Component rigidity and off-axis loading can contribute to these undesirable effects. An elongate tube having a strong, flexible, cut wall pattern such as thepuzzle lock profile600 can improve system flexibility and reduce unwanted loading conditions.
• FIGS. 25A-25C illustrate apuzzle lock profile600 in accordance with an embodiment. Thepuzzle lock profile600 can be used to create highly flexible materials such as tubing with push, pull, and torque capabilities. Thepuzzle lock profile600 can be used to transmit axial loads and rotational torque loads while minimizing bending loads through its flexibility. As illustrated, one embodiment of thepuzzle lock profile600 comprises a cut through a tube or a layer of material using a laser or some other similar manufacturing means known in the art. Referring toFIG. 25B, illustrated is atube605 with alongitudinal axis610, adiametric axis620, and apuzzle lock profile600 cut into it. Thetube605 can be any tube or shaft discussed herein. Thelongitudinal axis610 runs along the general axis in the lumen of a tube or through the center of a solid tube when that tube is straight. Thediametric axis620 lies in a plane that is perpendicular to thelongitudinal axis610 and runs along a diameter of thetube605.
• In some embodiments, acut635 may start at either the proximal or distal end of thetube605. In other embodiments, acut635 may start at an offsetlength630 from an end of atube605. The offset630 may provide structural support to the ends of the tube or may represent an uncut tubing length prior to a puzzle cut region in a tube. A corresponding offset630 may exist at the other end of thetube605, and in some embodiments there may be a plurality of regions in atube605, alternating betweenpuzzle lock profile600 regions and uncut tubing or offset630 regions.
• Referring toFIG. 25C, apuzzle lock profile600 is presented in close up of atube605.FIG. 25C may also be considered a view of atube605 that has been sliced longitudinally and spread into a flat planar surface. In this view, acut635 can have acut axis640 which runs along the length of thecut635. As illustrated, the weaving cut635 follows a repeating pattern that is symmetric around thecut axis640. In one embodiment atube605 has a number of generally parallel cut axes640,650,660, and670. Additional cut axes may continue along a length of the tube605 (not illustrated). In one embodiment, cutaxes640,650,660, and670 may be parts of a single continuous cut that traverses external surface of atube605, similar to a spiral. In another embodiment, cutaxis640 and cutaxis650 may be two parallel cut axes that are offset from each other, creating two interlaced parallel spiral cuts along thetube605. In one embodiment, the two spiral cuts start 180 degrees from each other in a plane perpendicular to thelongitudinal axis610 of thetube605 to create two symmetric spiral cuts and two helical tube surfaces. The two starting points may be located on thediametric axis620 at intersection points with the external surface of thetube605. In this embodiment, afirst cut635 moves along acut axis640 which is contiguous withcut axis660, and asecond cut636 is contiguous withcut670. In other embodiments, there may be two, three, four, or a plurality of cuts, such ascut635, cut636, cut637 and cut638, that create parallel spiral cuts along thetube605 withcut axes640,650,660, and670, respectively, which can create either symmetric or non-symmetric spiral cuts and helical tube surfaces along thetube605.
• Referring toFIG. 25C, illustrated is an embodiment of apuzzle lock profile600 with asingle cut635 that extends along cut axes640,650,660, and670 each time thecut635 wraps around the outer circumference of atube605. Thecut635 extends generally around the circumference of thetube605 and follows a continuous repeating pattern which is inclined at a slight angle a from adiametric axis620 to alongitudinal axis610 of thetube605. Each of the cut axes640,650,660, and670 are parallel to each other with a planar cut axis that can be drawn along the general direction of thecut635. In one embodiment, acut635 is oriented to follow acut axis640 with an angle α of zero degrees, thecut axis640 being parallel to thediametric axis620 and perpendicular to thelongitudinal axis610 of thetube605, resulting in a cut that would traverse the circumference of thetube605 and return to the same location as its starting point, thereby creating a series of interlocked rings with multiple cuts. In another embodiment, angle α may be anywhere in a range of 0 to 90 degrees, where in some embodiments angle α may be about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 65, 70, 75, 80, 85, or 90 degrees. In the illustrated embodiment inFIG. 25C, angle a is in the range of about 5-7 degrees.
• Along a givencut axis640, thecut635 may run along a pattern that alternates on either side of thecut axis640 and that runs parallel to thecut axis640 at adistance642 and adistance643. In some embodiments,distance642 equalsdistance643. As acut635 alternates on either side of thecut axis640 the pattern cuts alength646 along acut axis640 when thecut635 is on thedistance643 from thecut axis640, and alength647 along acut axis640 when thecut635 is on thedistance642 from thecut axis640. In some embodiments,length646 equalslength647. As acut635 runs along a pattern at adistance643, it enters a bend toward thecut axis640. The bend has aradius644 which is on the order of half of thedistance643. As thecut635 approaches thecut axis640 the bend reaches an inflection point and changes direction, creating a bend with aradius645 which is on the order of half of thedistance642. In some embodiments,radius644 equalsradius645. These bends create a set of interlocking projections that keep the tube engaged to transmit axial loads and rotational loads about thelongitudinal axis610 while providing flexibility in thetube605 to reduce bending moments.
• The dimensions of acut635 with respect to acut axis640 depends on the desired push, pull, and torque characteristics of a giventube605, and may further depend ontube605 thickness, diameter, length, and material. In some embodiments, thetube605 is made of metal, stainless steel, hypodermic materials, nickel titanium, plastic, polymers, silver, or radiopaque visualization materials. Angles and lengths and various other dimensions depend on the number of parallel cuts that may be desired as well. Embodiments of thepuzzle lock profile600, as illustrated inFIGS. 25 and 25A-25C, may be used in the material of animplant actuation shaft334, alock tube234, acatheter body302, aretrieval catheter502, atranseptal sheath520, acatheter system300, aretrieval catheter system500, or any component of animplant delivery system50, as discussed herein. The puzzle-interlocking features338 illustrated provide super flexibility of the various tubes while maintaining push, pull and torque transmission capabilities. Any of the puzzle-interlockingprofile600 tubes can be covered with a thin silicone tubing to provide a seal over the interlocking portions of the tube to allow for transport of contrast or other fluids within the lumen of the tubes. In some embodiments, portions of tubes (such as aflexible core section372 or aflexible segment384 as illustrated inFIG. 24) which require greater flexibility can use thepuzzle lock profile600 which are attachable to other embodiments of the respective tube. In other embodiments, the entire tube or component can be constructed using apuzzle lock profile600.
• In one embodiment, apuzzle lock profile600 is incorporated into animplant actuation shaft334. Previous embodiments ofimplant actuation shafts334 have been described in terms of an axialmoveable core304 and atorque rod340, as discussed above relating to at leastFIGS. 17-21. Theimplant actuation shaft334 is generally a tubular structure for imparting a distal force on thedistal end102 of theimplant100. In various embodiments, theimplant actuation shaft334 can be a hypodermic or a metallic tube. In addition, theimplant actuation shaft334 can be cut (e.g., laser cut) to have a spiral or puzzle-lock wall profile600. One embodiment of apuzzle lock profile600 is shown inFIG. 25. A spiral cut has little resistance to bending, is capable of applying limited compression and can be torqued in one direction. The puzzle-lock profile600 cut has these same properties but is also capable of applying tension and torque in both directions. Thepuzzle lock338 is generally screwed in and out of thecatheter system300 in both clockwise and counter-clockwise directions. Since both cuts generally are not able to apply bending moment, they are both advantageously very flexible. Embodiments of puzzle-lock tubes are disclosed in U.S. Pat. No. 6,273,876, filed Nov. 3, 1998, which is incorporated by reference herein.
• Referring back toFIGS. 21A-21C, there is illustrated an embodiment of aflexible sock392, such as a metallic mesh sock392 (e.g., made from nickel titanium, or NITINOL), which partially covers at least a portion of animplant actuation shaft334 and aslide tube394. Theimplant actuation shaft334 works with thesock392 to collapse the implant. As discussed above, the memory metal properties of theimplant100 cause its natural state to be open, or radially expanded to an expanded-diameter configuration. Distal force is applied to override the natural state and place theimplant100 in tension in order to reduce theimplant100 to its reduced-diameter configuration. A small moment arm associated or combined with the distal force can cause thedelivery catheter302 to bend. This in turn can cause theimplant100 to shift and change its spatial orientation, depending upon the amount of force and/or the amount theimplant100 is collapsed. A concentric, 360° application of tension concentric to the compression force deliveringimplant actuation shaft334 helps achieve non-biased expansion of theimplant100. The tension member in the form of asock392 avoids applying bending moment, as previously discussed. It also avoids applying compression. In order for the left atrial appendage (not illustrated here) to naturally assert its influence on theimplant100 and for theimplant100 to be properly seated within the left atrial appendage, once the tension has been released, it is advantageous if no additional expansion loads are transmitted from thedelivery catheter302 to theimplant100. If there were, thedelivery catheter302 could falsely bias theimplant100 into an exaggerated or over-expanded expanded state, which would not represent the final release conditions. In such cases the expansion force of theimplant100 could override the compression forces provided by the left atrial appendage.
• Thesock392, which can be a braided, multi-stranded nickel titanium tube, is preferably used to help achieve concentric application of tension to theimplant100. Prototypes have shown tensile forces exceeding two times those used to collapse theimplant100; no bending resistance; and no compression load transfer over the first 50% of axial strain (e.g., thesock392 flexibly collapses to a point, as illustrated inFIG. 21C). Thesock392 can provide tension forces to theproximal end104 of theimplant100 via thedisconnect flex fingers238 described above. Thesock392 can be attached to thedelivery catheter302 and disconnectmount236 using any method known to those of skill in the art, including adhesive, welds, bonds, mechanical links, pins, etc. In one embodiment, LOCTITE adhesive is used to bond the proximal end of thesock392 to the distal end of thedelivery catheter302. In other embodiments, thesock392 is trapped with a laser weld or swaged ring. Thesock392 can also be re-flowed directly into thedelivery catheter302 outer lumen or it can be an extension of a braid that can be provided in thedelivery catheter302. The ability of thesock392 to “spring back,” or return to its initial state without taking a permanent set helps maintain consistent expansion and collapse properties during theimplant100 deployment and recapture process. The super-elastic properties of NITINOL are well-suited for use as thesock392. In addition, a stainless steel braid will take a set and create compression bias as well. In one embodiment, thesock392 may use aspects of apuzzle lock profile600 as described above.
• In some embodiments, aslide tube394 is provided inside thesock392 and outside animplant actuation shaft334. Theslide tube394 may be used to prevent thesock392 from binding on aimplant actuation shaft334 or act as a stop in limiting axial motion of theimplant actuation shaft334. Theslide tube394 may slide freely with respect to theimplant actuation shaft334 or thecollar394 may be attached to theimplant actuation shaft334 in any number of ways know to the art. In one embodiment, theslide tube394 may be an integral part of theimplant actuation shaft334. As shown inFIGS. 21A-21C, an embodiment of animplant delivery system50 includes aslide tube394. A handle (not illustrated here) provides proximal tension, asock392 necks down onto theslide tube394 and pulls aproximal end104 of animplant100 away from itsdistal end102. Thedistal end102 is held “stationary” by animplant actuation shaft334. As thesock392 pulls theproximal end104 proximally with respect to thedistal end102, theimplant100 is reduced in diameter. As the tension on theproximal end104 is released theproximal end104 moves distally towards thedistal end102, and the implant's diameter expands. A control on the handle controls tension on theproximal end104.
• B. Configurations and Methods of Use of an Implant Delivery System
• Referring toFIG. 6, illustrated is an embodiment of animplant delivery system50. The system and method allows for access and assessment of theLAA10. In one embodiment, a guidewire (not shown) is used to access the superior vena cava through groin access. Atransseptal sheath520 is advanced over the guidewire and into the superior vena cava. The guidewire is removed and replaced with a transseptal needle (not shown). Thetransseptal sheath520 preferably is retracted inferiorly so that a bend in the transseptal sheath directs the distal tip of the transseptal sheath toward the fossa ovalis. The needle is advanced to puncture the fossa ovalis. Thetransseptal sheath520 is advanced to establish access to theLAA10 and the needle is retracted. Further details or disclosure are provided above and in copending U.S. patent application Ser. No. 09/435,562 and U.S. Pat. No. 7,044,134, issued May 16, 2006, the entireties of which are hereby incorporated by reference.
• After preparing atransseptal sheath520 forLAA10 access, the size of the neck diameter and morphology of theLAA10 preferably is determined by advancing thetransseptal sheath520 to the distal portion of theLAA10 and injecting contrast media to obtain an initial left atrial appendogram. The neck diameter preferably is measured approximately 5 mm in from the ostium of theLAA10 at end diastole.
• Referring toFIG. 22, illustrated is an embodiment of a system and method that allows for selection and preparation of adeployment system50. Adeployment system50 preferably comprises animplant100 of an appropriate size for placement in a patient. Initially, theimplant100 preferably is in an expanded configuration, with an implant release and recapturemechanism200 engaging theimplant100, as described above. The recapturesheath522 preferably is positioned so it covers and supports theflexible segment384 of thedelivery system50, wherein theflexible catheter section362 ofdeployment catheter302 andflexible core section372 of axiallymoveable core304 are aligned. The Touhy-Borst valve530 preferably is tightened over thedeployment catheter302 to prevent relative movement between recapturesheath522 anddeployment catheter302. Theloading collar323 and peel-awaysheath314 preferably are positioned so they are at the base of the recaptureflares510, proximal thereto.
• In one embodiment, thedelivery system50 is loaded by rotating thecontrol knob408 counterclockwise until theimplant100 is fully collapsed. Preferably, at least a portion of thecontrol line312 is coupled with thecontrol knob408 such that rotation of thecontrol knob408 retracts at least a portion of thecontrol line312. In an embodiment, the rotation of thecontrol knob408 is in the counterclockwise direction to retract at least a portion of thecontrol line312. Retraction of thecontrol line312 preferably places tension on theproximal hub104 of theimplant100, because a portion of thecontrol line312 preferably is coupled with theproximal hub104 by apin146. While the distal portion of the axiallymoveable core304 applies a distal force todistal hub108 of theimplant100, tension in thecontrol line312 preferably causes theproximal hub104 of theimplant100 to move proximally relative the axiallymoveable core304, thereby collapsing theimplant100.
• In another embodiment, thedelivery system50 is loaded with animplant100 connected to an implant release and recapturemechanism200, which is connected to acatheter system300, which is connected to adeployment handle400. Adisconnect mount interface180 on theproximal end104 of theimplant100 is connected to adisconnect mount236 on acatheter system300 which can provide releasable concentric loading to theimplant100 as described above. In one embodiment, the concentric loading is concentric tension. In one embodiment the concentric loading is provided by adisconnect mount interface180 with afinger interface182 which interacts with aflexible finger238 on thedisconnect mount236. Embodiments of thefinger interface182 may be in the form of a protruding finger, an interlocking feature, a groove, a slot, a window, or other similar features for releasably holding adisconnect mount236flexible finger238. In one embodiment theflexible finger238 is engaged with thefinger interface182 and alock tube234 is slid into place to secure the engagement between theflexible finger238 is engaged with thefinger interface182. In some embodiments, thelock tube234 may be rotated to threadably engage with acatheter302 to lock in place. In other embodiments nolock tube234 is necessary.
• Animplant actuation shaft334 may be extended distally through thecatheter302 into theimplant100 to radially-reduce theimplant100 by placing theimplant100 in tension. Theimplant actuation shaft334 may be advanced distally by axial sliding, rotational engagement with a threadedsurface336, or a combination of both. In one embodiment, theimplant actuation shaft334 has a threadedportion336 that threadably engages with ahub236 to lock theimplant100 in a radially reduced configuration, as described above. In this embodiment, theimplant100 may be loaded by sliding theimplant actuation shaft334 distally until its threadedportion336 comes into contact thehub236, and then rotating thecontrol knob408 counterclockwise to threadably engage the threadedportion336 and thehub236 until theimplant100 is fully collapsed.
• The diameter of theimplant100 preferably is reduced to approximately ⅓^rdor less of its original diameter when collapsed. Theloading collar323 and peel-awaysheath314 are then advanced distally over theflares510 andimplant100 until the distal tip of theimplant100 is aligned with the distal end of the peel-awaysheath314 and the distal end of the loading collar is about 1.5 cm from the distal tip of theimplant100. At this point, theflares510 partially cover the implant. Theloading collar323 preferably is removed and discarded.
• With theimplant100 partially within the recapturesheath522 and retracted within the peel-awaysheath314, the entire system preferably is flushed with sterile heparinized saline after attaching stopcocks to the recapturesheath injection port529, theproximal injection port412 anddistal injection port414 of thedelivery system50. The recapturesheath522 and the Touhy-Borst valve530 are first thoroughly flushed throughport529. Then thedistal injection port414 and theproximal injection port412 of thedeployment handle400 are preferably flushed through. Thedistal injection port414 is in fluid communication withlumen388 of axially moveable core304 (as illustrated inFIG. 24A), andproximal injection port412 is in fluid communication withinjection lumens332 ofmultilumen shaft326. Thetransseptal sheath520 placement preferably is reconfirmed using fluoroscopy and contrast media injection.
• Thedelivery system50, as described above, withimplant100 inserted therein, preferably is then inserted into the proximal end of a transseptal sheath520 (as shown inFIG. 6). To avoid introducing air into thetransseptal sheath520 during insertion of thedelivery system50, a continual, slow flush of sterile heparinized saline preferably is applied through theproximal injection port412 of the deployment handle400 to the distal end of thedeployment catheter302 until the tip of the peel-awaysheath314 has been inserted into, and stops in, the hemostatic valve of thetransseptal sheath520. Preferably, the distal tip of the peel-awaysheath314 is inserted approximately 5 mm relative to the proximal end of thetransseptal sheath520.
• Under fluoroscopy, the recapturesheath522 anddeployment catheter302 preferably are advanced, relative to the peel-awaysheath314, approximately 20-30 cm from the proximal end of thetransseptal sheath520, and thesystem50 preferably is evaluated for trapped air. The peel-awaysheath314 is preferably not advanced into thetransseptal sheath520 due to a hemostasis valve (not illustrated) on thetransseptal sheath520 blocking its passage. If air is present in thesystem50, it may be removed by aspirating through thedistal injection port414, recapturesheath injection port529, orproximal injection port412. If air cannot be aspirated, thedeployment catheter302 and recapturesheath522 preferably are moved proximally and thedelivery system50 preferably is removed from thetransseptal sheath520. All air preferably is aspirated and the flushing/introduction procedure preferably is repeated.
• The peel-awaysheath314 preferably is manually slid proximally to theproximal end524 of the recapturesheath522. The Touhy-Borst valve530 preferably is loosened and thedeployment catheter302 preferably is advanced distally relative to the recapturesheath522 until thedeployment handle400 is within about 2 cm of the Touhy-Borst valve530 of the recapturesheath522. This causes theimplant100 to be advanced distally within thetransseptal sheath520 such that the recapturesheath522 no longer covers theimplant100 or theflexible section558. The Touhy-Borst valve530 preferably is tightened to secure thedeployment catheter302 to fix relative movement between thedeployment catheter302 and recapturesheath522.
• Under fluoroscopy, theimplant100 preferably is advanced to the tip of thetransseptal sheath520 by distal movement of thedelivery catheter302. Thedistal hub108 ofimplant100 preferably is aligned with a transseptal sheath tip radiopaque marker521 (seeFIG. 6). Under fluoroscopy, thesheath520 positioning within theLAA10 preferably is confirmed with a distal contrast media injection.
• The position of theimplant100 preferably is maintained by holding the deployment handle400 stable. Thetransseptal sheath520 preferably is withdrawn proximally until its tipradiopaque marker521 is aligned with the distal end of the deployment catheterflexible segment384. In some embodiments, thetransseptal sheath520 is withdrawn proximally until its tipradiopaque marker521 is aligned with the distal end of themesh sock392. In other embodiments, thetransseptal sheath520 is withdrawn proximally until its tipradiopaque marker521 is aligned with the proximal end of themesh sock392, or at a location between the proximal and distal ends of themesh sock392. This preferably exposes theimplant100.
• In one embodiment, under fluoroscopy, theimplant100 preferably is expanded by rotating thecontrol knob408 clockwise until it stops. Rotating thecontrol knob408 preferably releases tension on thecontrol line312, preferably allowing theimplant100 to expand. Theimplant100 preferably is self-expanding. After expansion, any tension on theLAA10 preferably is removed by carefully retracting thedeployment handle400 under fluoroscopy until the radiopaque marker360 (seeFIG. 24) on the axiallymovable core304 moves proximally approximately 1-2 mm in the guide tube130 (seeFIG. 11). In an embodiment, the position of theimplant100 relative theLAA10 preferably is not altered because the axiallymovable core304 preferably is coupled with an axially decoupled implant release and recapturemechanism200, as is shown in an embodiment illustrated inFIGS. 16A and 16B, which allows for relative movement between theimplant100 and the axiallymovable core304. The implant release and recapturemechanism200 preferably allows for the distal portion of the axiallymovable core304 to be slightly retracted proximally from thedistal end102 of theimplant100, thereby removing any axial tension that may be acting on theimplant100 through the axiallymovable core304. The axialmoveable core304radiopaque marker360 preferably is about 1-2 mm proximal from theimplant100distal end102, and thetransseptal sheath520 tip preferably is about 2-3 mm proximal from the implantproximal end104, thereby indicating a neutral position.
• In another embodiment, thedelivery system50 comprises animplant100 connected to an implant release and recapturemechanism200, which is connected to acatheter system300, which is connected to adeployment handle400. Adisconnect mount interface180 on theproximal end104 of theimplant100 is connected to adisconnect mount236 on acatheter system300 which provides releasable concentric loading to theimplant100 as described above. In one embodiment, the concentric loading is concentric tension. In one embodiment the concentric loading is provided by adisconnect mount interface180 with afinger interface182 which interacts with aflexible finger238 on thedisconnect mount236.
• As discussed above, in some embodiments the order of the following steps may be accomplished in the following sequence, or in reverse sequence, or in a combination of repeated steps in order to have theimplant100 expand and release animplant100 in a distal, proximal, or relatively axially-stationary direction.
• In one embodiment, theimplant actuation shaft334 may be retracted proximally through thecatheter302 through theimplant100 to radially-expand theimplant100 by removing the tensile load fromdistal end102 of theimplant100. Theimplant actuation shaft334 may be retracted proximally by axial sliding, rotational engagement with a threadedsurface336, or a combination of both. In one embodiment, theimplant actuation shaft334 has a threadedportion336 that threadably engages with ahub236 to lock theimplant100 in a radially reduced configuration, as described above. In this embodiment, theimplant100 may be unloaded rotating thecontrol knob408 until thehub236 andimplant actuation shaft334 threadedportion336 detach, and by sliding theimplant actuation shaft334 proximally. If theimplant actuation shaft334 is moved proximally and theproximal end104 of theimplant100 remains relatively stationary with respect to thecatheter body302, theimplant100 will expand within theLAA10 in a generally proximal direction, as described above.
• In one embodiment adisconnect mount interface180 on theproximal end104 of theimplant100 is connected to adisconnect mount236 on acatheter system300 which can provide releasable concentric loading to theimplant100 as described above. In one embodiment, the concentric loading is concentric tension. In one embodiment the concentric loading is provided by adisconnect mount interface180 with afinger interface182 which interacts with aflexible finger238 on thedisconnect mount236. Theflexible finger238 is engaged with thefinger interface182 and alock tube234 secures the engagement between theflexible finger238 and thefinger interface182. In one embodiment, theimplant100 may be expanded by allowing thecatheter302 to advance distally while theimplant actuation shaft334 remains stationary at thedistal end102 of theimplant100 as is illustrated inFIGS. 18A and 18B. In another embodiment, amesh sock392 in a compressed state may be released to allow theproximal end104 of theimplant100 to move distally while theimplant actuation shaft334 remains stationary at thedistal end102 of theimplant100. In another embodiment, theimplant100 may be expanded by removing thelock tube234 from theflexible finger238 andfinger interface182. In some embodiments, thelock tube234 may be rotated to threadably disengage from acatheter302 to unlock thelock tube234. In other embodiments nolock tube234 is necessary. When theimplant actuation shaft334 remains extended and attached to theproximal end104 of theimplant100 and thefingers238 are released from the finger interfaces182, theimplant100 will expand within theLAA10 in a generally distal direction, as described above.
• Theimplant100 preferably is self-expanding. After expansion, any tension on theLAA10 preferably is removed by carefully retracting thedeployment handle400 under fluoroscopy until the radiopaque marker360 (seeFIG. 24) on the axiallymovable core304 moves proximally approximately 1-2 mm in the guide tube130 (seeFIG. 11). In an embodiment, the position of theimplant100 relative theLAA10 preferably is not altered because theimplant actuation shaft334 preferably is coupled with an axially decoupled implant release and recapturemechanism200, as is shown in an embodiment illustrated inFIGS. 16A and 16B, which allows for relative movement between theimplant100 and theimplant actuation shaft334. The implant release and recapturemechanism200 preferably allows for the distal portion of the axiallymovable core304 to be slightly retracted proximally from thedistal end102 of theimplant100, thereby removing any axial tension that may be acting on theimplant100 through the axiallymovable core304. The axialmoveable core304radiopaque marker360 preferably is about 1-2 mm proximal from theimplant100distal end102, and thetransseptal sheath520 tip preferably is about 2-3 mm proximal from the implantproximal end104, thereby indicating a neutral position.
• Under fluoroscopy, the expanded diameter (Ø inFIG. 6) of theimplant100 preferably is measured in at least two views to assess the position of the implant within theLAA10. The measured implant diameter Ø preferably is compared to the maximum expanded diameter.
• Preferably, the labeled proximal412 anddistal injection ports414, of the deployment handle400 shown inFIG. 22, correlate with the proximal and distal contrast media injections. The proximal contrast media injections are delivered through thedelivery catheter lumen332 to a location proximal to theimplant100. The distal contrast media injections are delivered through the axiallymovable core304 to a location distal to theimplant100. Proximal contrast media injections preferably are completed in two views. If the injection rate is insufficient, the recapturesheath injection port529 may be used independently or in conjunction with theproximal injection port412 to deliver fluid to a location proximal to theimplant100.
• If satisfactory results are seen, any transverse tension on theLAA10 preferably is released by exposing theflexible segment384 of thedelivery system50. Theflexible catheter section362 and theflexible core section372 preferably are linearly co-located to cooperate as theflexible segment384 of thedelivery system50. This preferably is accomplished by retracting thetransseptal sheath520 proximally approximately 2 cm to expose the flexible segment. By exposing theflexible segment384, theflexible segment384 preferably will flex to allow theimplant100 to sit within theLAA10 free from transverse forces that may be created, for example, by contractions of the heart acting against thetransseptal sheath520 ordeployment catheter302. Once theflexible segment384 is exposed, distal contrast media injections preferably are completed in at least two views to verify proper positioning of theimplant100. A flush of saline preferably is used as needed between injections to clear the contrast media from theLAA10. Following the contrast media injections, thetransseptal sheath520 preferably is advanced distally to cover theflexible segment384.
• In another embodiment, any transverse tension on theLAA10 preferably is released by amesh sock392 and a proximal retraction of animplant actuation shaft334.
• Ifimplant100 position or results are sub-optimal, theimplant100 preferably may be collapsed and repositioned in theLAA10. In some embodiments, theimplant100 is still attached to an implant release and recapturemechanism200 and the radial-reduction of theimplant100 is accomplished?by the actuation of theimplant actuation shaft334. In other embodiments, theimplant100 must be reattached to the implant release and recapturemechanism200 before the radial-reduction of theimplant100 can be accomplished by the actuation of theimplant actuation shaft334. To collapse and reposition animplant100 in one embodiment under fluoroscopy, the deployment handle400 preferably is advanced distally to place theradiopaque marker360 of the axiallymoveable core304 at thedistal hub108 of theimplant100. The distal end of thetransseptal sheath520 preferably is aligned with the distal end of theflexible segment384. Thecontrol knob408 preferably is rotated until theimplant100 has been collapsed to approximately ⅓^rdor less of its expanded diameter. Thecontrol knob408 preferably acts on thecontrol line312 to place tension on theproximal hub104 of theimplant100, pulling theproximal hub104 of theimplant100 proximally relative thedistal hub108 of theimplant100 to collapse theimplant100. Theimplant100 preferably can be repositioned and re-expanded. In another embodiment, animplant actuation shaft334 is reintroduced or advanced distally within a radially-enlargedimplant100 and advanced to thedistal end102 of theimplant100.
• The stability of theimplant100 preferably is verified in several views. Stability tests preferably are preformed in the following manner. A contrast media filled syringe preferably is connected to thedistal injection port414 of thedeployment handle400. Under fluoroscopy, at least about a 10 mm gap between the tip of thetransseptal sheath520 and theproximal hub110 of theimplant100 is preferably confirmed. The stability of theimplant100 in theLAA10 preferably is evaluated using fluoroscopy and echocardiography. The recapture sheath Touhy-Borst valve530 preferably is loosened. Then the deployment handle400 preferably is alternately retracted and advanced about 5-10 mm while maintaining the position of thetransseptal sheath520 and simultaneously injecting contrast media through thedistal injection port414. This tests how well the implant is held within theLAA10. If the implant stability tests are unacceptable, theimplant100 preferably may be collapsed and repositioned as described above. If repositioning theimplant100 does not achieve an acceptable result, theimplant100 preferably may be collapsed and recaptured as described further below.
• Theimplant100 preferably meets the following acceptance criteria, associated with the assessment techniques listed below, prior to being released. The assessment techniques to be evaluated preferably include 1) residual compression; 2) implant location; 3) anchor engagement; 4) seal quality; and 5) stability. For residual compression, the implant diameter0, as measured by fluoroscopic imaging, preferably is less than the maximum expanded diameter of theimplant100. For implant location, the proximal sealing surface of theimplant100 preferably is positioned between theLAA10 ostium and sources of thrombus formation (pectinates, secondary lobes, etc.) (preferably imaged in at least two views). For anchor engagement, theimplant frame101 preferably is positioned within theLAA10 so as to completely engage a middle row ofanchors118 in anLAA10 wall (preferably imaged in at least two views). For seal quality, the contrast injections preferably show leakage rated no worse than mild (preferably defined as a flow of contrast media, well defined, and filling one-third of theLAA10 during a proximal injection over a period of up to about five ventricular beats, preferably imaged in at least two views). For stability, there preferably is no migration or movement of theimplant100 relative to theLAA10 wall as a result of the Stability Test.
• Ifimplant100 recapture is necessary, because adifferent size implant100 is necessary or desired, or if acceptable positioning or sealing cannot be achieved, theimplant100 preferably is fully collapsed as described above. In one embodiment, once theimplant100 is collapsed, thelocking collar315 of the peel awaysheath314 preferably is unlocked. The peel-awayportion524 of the peel-awaysheath314 preferably is split up to the reinforcedsection317 and removed. The reinforcedsection317 of the peel-awaysheath314 preferably is slid proximally to the hub of the recapturesheath522. The Touhy-Borst valve530 on the proximal end of the recapturesheath522 preferably is slightly loosened to allow smooth movement of thesheath522 overdeployment catheter302 without allowing air to enter past the Touhy-Borst valve530 seal. By removing the peel-awayportion524 of peel-awaysheath314, the recapturesheath522 can now be advanced further distally relative to thetransseptal sheath520.
• While holding thedeployment catheter302 andtransseptal sheath520 in place, the recapturesheath522 preferably is advanced distally into thetransseptal sheath520 until a half marker band536 on the recapturesheath522 is aligned with afull marker band521 on thetransseptal sheath520. This preferably exposes the recaptureflares510 outside the transseptal sheath.
• Thecollapsed implant100 preferably is retracted into the recapturesheath522 by simultaneously pulling thedeployment handle400 and maintaining the position of the recapturesheath522 until approximately half theimplant100 is seated in the recapturesheath522. The Touhy-Borst valve530 on the recapturesheath522 preferably is tightened over thedeployment catheter302. The recapturesheath522 andimplant100 preferably are retracted into thetransseptal sheath520 by pulling on the recapturesheath522 while maintaining the position of thetransseptal sheath520, preferably maintaining left atrial access. The recapture flares510 of the recapturesheath522 preferably cover at least some of the anchor elements195 on theimplant100 as the implant is retracted proximally into thetransseptal sheath520. Further details are described above with respect toFIGS. 15C-15E.
• If the implant's position and function are acceptable, and implant recapture is not necessary, theimplant100 preferably is released from thedelivery system50. In one embodiment, under fluoroscopy, thetransseptal sheath520 is advanced to theproximal hub104 of theimplant100 for support. Therelease knob410 on the proximal end of the deployment handle400 preferably is rotated to release theimplant100. Rotating therelease knob410 preferably causes a threaded portion of thedistal shaft344 of the axiallymovable core304 to rotate with respect to the threadedaperture346 such that the threaded portion of thedistal shaft344 preferably is decoupled from theimplant100. Under fluoroscopy, after the axiallymovable core304 is decoupled from theimplant100, therelease knob410 preferably is retracted until thedistal end310 of the axiallymovable core304 is at least about 2 cm within thetransseptal sheath520.
• In one embodiment adisconnect mount interface180 on theproximal end104 of theimplant100 is connected to adisconnect mount236 on acatheter system300 which can provide releasable concentric loading to theimplant100 as described above. In one embodiment, the concentric loading is concentric tension. In one embodiment the concentric loading is provided by adisconnect mount interface180 with afinger interface182 which interacts with aflexible finger238 on thedisconnect mount236. Theflexible finger238 is engaged with afinger interface182 and alock tube234 secures the engagement between theflexible finger238 and thefinger interface182. Under fluoroscopy, theimplant100 may be detached by removing thelock tube234 from theflexible finger238 andfinger interface182. In some embodiments, thelock tube234 may be rotated to threadably disengage from acatheter302 to unlock thelock tube234. In other embodiments nolock tube234 is necessary. In other embodiments sufficient proximal retraction of theimplant actuation shaft334 is required in order to release thedisconnect mount interface180 from thedisconnect mount236, as described above.
• Under fluoroscopy, while assuring that transseptal access is maintained, thedelivery system50 preferably is retracted and removed through thetransseptal sheath520. Under fluoroscopy, thetransseptal sheath520 position preferably is verified to be approximately 1 cm away from the face of theimplant100. Contrast injections, fluoroscopy and/or echocardiography preferably may be used to confirm proper positioning and delivery of theimplant100 and containment of theLAA10. Thetransseptal sheath520 preferably is withdrawn.
• Throughout this application the terms implant and occlusion device have been used. One of ordinary skill in the art will appreciate that all of the disclosures herein are applicable to a wide variety of structures that include both implants that may or may not also be occlusion devices. Routine experimentation will demonstrate those limited circumstances under which certain disclosures and combinations thereof are not beneficial.
• Further details regarding left atrial appendages devices and related methods are disclosed in U.S. Pat. No. 6,152,144, titled “Method and Device for Left Atrial Appendage Occlusion,” filed Nov. 6, 1998, U.S. patent application Ser. No. 09/435,562, filed Nov. 8, 1999, U.S. patent application Ser. No. 10/033,371, titled “Method and Device for Left Atrial Appendage Occlusion,” filed Oct. 19, 2001, and U.S. application Ser. No. 10/642,384, filed Aug. 15, 2003, titled “System and Method for Delivering a Left Atrial Appendage Containment Device,” published as U.S. Publication No. 2005/0038470. The entirety of each of these is hereby incorporated by reference.
• While particular forms of the invention have been described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.

Claims (20)

1. An implant delivery system, comprising:

an implantable device comprising a plurality of supports extending between a proximal end and a distal end, the supports being moveable between a collapsed configuration and an expanded configuration;

a proximal guide tube at the proximal end of the supports extending toward the distal end; and

a distal guide tube at the distal end of the supports extending toward the proximal end;

wherein the proximal and distal guide tubes are telescoping and become further engaged as the supports move from the collapsed to the expanded configuration.

2. The implant delivery system ofclaim 1, further comprising an actuation shaft extendable through the proximal guide tube and into engagement with the distal guide tube.

3. The implant delivery system ofclaim 2, wherein the actuation shaft comprises a flexible segment configured to flex upon proximal retraction of the actuation shaft from the proximal and distal guide tubes.

4. The implant delivery system ofclaim 1, further comprising a catheter, the catheter comprising a disconnect mount configured to concentrically engage the proximal end of the implantable device.

5. The implant delivery system ofclaim 4, wherein activation of the disconnect mount causes the catheter to disengage the implantable device without substantially affecting the implantable device position.

6. The implant delivery system ofclaim 4, wherein the disconnect mount comprises flexible fingers extending distally with respect to the catheter.

7. The implantable delivery system ofclaim 6, wherein the flexible fingers are biased to flex outward.

8. An implant delivery system, comprising:

an implantable device having a proximal end and a distal end and a plurality of supports extending therebetween, the implantable device being moveable between a collapsed configuration and an expanded configuration;

a distal guide tube at the distal end of the supports extending toward the proximal end;

an actuation shaft extendable through the proximal end of the implantable device and removeably engageable with the distal guide tube; and

a disconnect mount releasably engageable with the proximal end of the implantable device, the disconnect mount being concentrically attachable to the proximal end;

wherein the implantable device is self-expandable and is collapsed by engaging the actuation shaft with the distal guide tube while applying a relatively proximal force to the proximal end of the implantable device with the disconnect mount.

9. The implant delivery system ofclaim 8, wherein the disconnect mount is hollow and the actuation shaft is positioned within the disconnect mount.

10. The implant delivery system ofclaim 9, wherein the disconnect mount comprises moveable distal fingers that are releasably engageable with the proximal end of the implantable device.

11. The implant delivery system ofclaim 10, further comprising a locking tube, wherein the locking tube extends over the actuation shaft within the disconnect mount and is positioned distal to the distal fingers when the disconnect mount is engaged with the implantable device, and is positioned proximal to the distal fingers when the disconnect mount is released from the implantable device.

12. The implant delivery system ofclaim 10, further comprising a locking tube, wherein the locking tube extends over the actuation shaft and over the disconnect mount, wherein the locking tube is positioned to cover at least a portion of the distal fingers when the disconnect mount is engaged with the implantable device, and wherein the locking tube is positioned proximal to the distal fingers when the disconnect mount is released from the implantable device.

13. The implant delivery system ofclaim 8, further comprising a metallic mesh sock attached to the disconnect mount.

14. The implant delivery system ofclaim 8, further comprising a proximal guide tube at the proximal end of the supports extending towards the distal end and configured to telescopically engage the distal guide tube when the implant is expanded.

15. A method of actuating an implantable device with a concentric force, the method comprising:

providing an implantable device having a proximal end, a distal end, and a plurality of supports extending therebetween, the implantable device configured to expand from a reduced-diameter configuration to an expanded-diameter configuration;

applying a concentric force to the proximal end; and

applying a distal force to the distal end.

16. The method ofclaim 15, further comprising expanding the implantable device by reducing the distal force while maintaining the concentric force.

17. The method ofclaim 16, wherein said reducing the distal force comprises moving an actuation core in contact with the distal end in a proximal direction with respect to the implantable device.

18. The method ofclaim 16, further comprising releasing the implantable device from a catheter by reducing the concentric force.

19. The method ofclaim 18, wherein said releasing does not cause the implantable device to substantially change its position with respect to the catheter.

20. The method ofclaim 15, further comprising collapsing the implantable device by applying a pulling force on the proximal end with a disconnect mount, wherein the disconnect mount is configured to provide the concentric force.

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