US20090287304A1 - Medical Device for Constricting Tissue or a Bodily Orifice, for example a mitral valve - Google Patents

Abstract

A medical apparatus positionable in a cavity of a bodily organ (e.g., a heart) may constrict a bodily orifice (e.g., a mitral valve). The medical apparatus may include tissue anchors that are implanted in the annulus of the orifice. The tissue anchors may be guided into position by an intravascularly or percutaneously deployed anchor guiding frame. Constriction of the orifice may be accomplished by cinching a flexible cable attached to implanted tissue anchors. The medical device may be used to approximate the septal and lateral (clinically referred to as anterior and posterior) annulus of the mitral valve in order to move the posterior leaflet anteriorly and the anterior leaflet posteriorly and thereby improve leaflet coaptation and eliminate mitral regurgitation.

Description

BACKGROUND
• 1. Field
• This disclosure is generally related to percutaneous or minimally invasive surgery, and more particularly to percutaneously deployed medical devices suitable for constricting tissue or a bodily orifice such as a mitral valve
• 2. Description of the Related Art
• Cardiac surgery was initially undertaken only by performing a sternotomy, a type of incision in the center of the chest, which separates the sternum (chest bone) to allow access to the heart. In the previous several decades, more and more cardiac operations are performed using a percutaneous technique, which is a medical procedure where access to inner organs or other tissue is gained via a catheter.
• Percutaneous surgeries benefit patients by reducing surgery risk, complications, and recovery time. However, the use of percutaneous technologies also raises some particular challenges. Medical devices used in percutaneous surgery need to be deployed via narrow tubes called catheter sheaths, which significantly increase the complexity of the device structure. As well, doctors do not have direct visual contact with the medical tools used once they are placed within the body, and positioning the tools correctly and operating the tools successfully can often be very challenging.
• One example of where percutaneous medical techniques are starting to be used is in the treatment of a heart disorder called mitral regurgitation. Mitral regurgitation is a condition in which blood flows backward from the left ventricle into the left atrium. The mitral apparatus is made up of four major structural components and includes the annulus, the two leaflets, the chordae and the papillary muscles. Improper function of any one of these structures or in combination can lead to mitral regurgitation. Annular dilation is a major component in the pathology of mitral regurgitation regardless of causes and is manifested in mitral regurgitation related to dilated cardiomyopathy and chronic mitral regurgitation due to ischemia.
• The mitral valve is intended to prevent the undesired flow of blood from the left ventricle into the left atrium when the left ventricle contracts. In a normal mitral valve, the geometry of the mitral valve ensures the cusps overlay each other to preclude the regurgitation of blood during left ventricular contraction and thereby prevent elevation of pulmonary vascular pressures and resultant symptoms of shortness of breath. Studies of the natural history of mitral regurgitation have found that totally asymptomatic patients with severe mitral insufficiency usually progress to severe disability within 5 years.
• At present treatment consists of either mitral valve replacement or repair. Both methods require open heart surgery. Replacement can be performed with either mechanical or biological valves and is particularly suitable when one of the mitral cusps has been severely damaged or deformed. The mechanical valve carries the risk of thromboembolism and requires anticoagulation with all of its potential hazards, whereas the biological prosthesis suffers from limited durability. Another hazard with replacement is the risk of endocarditis. These risks and other valve related complications are greatly diminished with valve repair. Mitral valve repair is theoretically possible if the mitral valve leaflets are structurally normal but fail to appropriately coapt because of annular dilatation and/or papillary muscle dysfunction. Various surgical procedures have been developed to improve coaptation of the leaflet and to correct the deformation of the mitral valve annulus and retain the intact natural heart valve function. These procedures generally involve reducing the circumference of the posterior mitral leaflet annulus (lateral annulus) where most of the dilatation occurs. The annulus of the anterior leaflet (septal annulus) does not generally dilate because it is anchored to the fibrous skeleton at the base of the heart. Such techniques, known as mitral annuloplasty, typically suture a prosthesis around the base of the valve leaflets shortening the lateral annulus to reshape the mitral valve annulus and minimize further dilation. Different types of mitral annuloplasty prostheses have been developed for use in such surgery. In general, such prostheses are annular or partially annular shaped and may be formed from rigid or flexible material.
• Mitral valve surgery requires an extremely invasive approach that includes a chest wall incision, cardiopulmonary bypass, cardiac and pulmonary arrest, and an incision on the heart itself to gain access to the mitral valve. Such a procedure is expensive, requires considerable time, and is associated with high morbidity and mortality. Due to the risks associated with this procedure, many of the sickest patients are denied the potential benefits of surgical correction of mitral regurgitation. In addition, patients with moderate, symptomatic mitral regurgitation are denied early intervention and undergo surgical correction only after the development of cardiac dysfunction. Furthermore, the effectiveness of such procedures is difficult to assess during the procedure and may not be known until a much later time. Hence, the ability to make adjustments to or changes in the prosthesis function to obtain optimum effectiveness is extremely limited. Correction at a later date would require another open heart procedure.
• In an attempt to treat mitral regurgitation without the need for cardiopulmonary bypass and without opening the chest, percutaneous approaches have been devised to repair the valve or place a correcting apparatus for correcting the annulus relaxation. Such approaches make use of devices which can be generally grouped into two types:
• • devices deforming (mainly shortening) the coronary sinus
  • devices pulling together two anchor points in order to affect the mitral valve, one of the anchor points can be the coronary sinus (typically using a wire that is pulled and secured).
• Neither approach emulates the current “gold standard” in mitral valve repair—annuloplasty using a ring the completely encircles the mitral valve. Both approaches suffer from several problems as a result of attempting to reshape the mitral annulus using an alternative method. Devices that deform the coronary sinus, while suitable for percutaneous procedures, are not effective in controlling the leakage of the mitral valve as the forces are not applied from the correct opposite sides of the valve, which are the lateral annulus and the septal annulus. The prior art devices of the second type are not easily adapted to a percutaneous procedure. In order to achieve shortening in the direction connecting the lateral annulus to the septal annulus the anchor points have to be located along this line, so pulling them together will affect the desired direction of shortening. Pulling applied along a different direction will distort the mitral valve but will not achieve the optimal approximation of the two leaflets.
• Thus, there is a need for methods and apparatus that enable the ability to create a full ring mitral annuloplasty via a percutaneous or intravascular procedure.
BRIEF SUMMARY OF THE INVENTION
• The present design of a medical device with enhanced capabilities for percutaneous deployment and annulus cinching employs a superior method for constricting tissue or a bodily orifice, such as the mitral valve, tricuspid valve, or aortic valve. The device may employ methods that enable a complete ring to be anchored to tissue and may enable reduction of the circumference of said ring during installation or at a later time. Reference throughout this specification is made to cardiac surgery, but the invention may also be used in gastric surgery, bowel surgery, or other surgeries in which tissue may be drawn together. The invention may also be used to draw or hold tissue not part of an orifice or annulus together. The invention may be used in minimally invasive surgery as well as intravascular or percutaneous surgery. Other advantages will become apparent from the teaching herein to those of skill in the art.
• At least one embodiment may be summarized as a method of constricting tissue or a bodily orifice or cavity, the method comprising delivering a plurality of anchors to the tissue or bodily orifice or cavity intravascularly; implanting the plurality of anchors; connecting the plurality of anchors by at least one joining member; and contracting at least one joining member.
• The method may further include constricting a bodily orifice that is a mitral valve. The method may further include a flexible cable as the joining member. The anchors may comprise a helical portion or multiple barbs. The method may further include guiding the plurality of anchors to implant sites by means of at least one guide rail. The plurality of anchors may be released proximate to a change in curvature of the guide rail. Guide rails may be connected at distal tips.
• At least one embodiment may be summarized as a medical system for constricting an orifice including a device positionable in at least a portion of a bodily organ; a plurality of guide rails; a plurality of anchors releasably guided by said guide rails; at least one structure used to locate said guide rails; means of connecting said anchors and a means of shortening or bending said connecting means.
• The system may be deployed intravascularly. The medical system may be positionable in a left atrium of a heart. The system may further include a plurality of anchors that are released proximate to a change in curvature of said guide rails. The plurality of anchors may be held captive within a cap prior to deployment. The plurality of anchors may be restricted from release from guide rails or other restraining member until anchors are implanted into tissue. The system may further include a means of connecting anchors by a member that is shortened by application of an external magnetic field. The medical system may be foldable into a catheter.
• At least one embodiment may be summarized as a medical system for attaching a flexible member to tissue including a flexible member attached to tissue by a plurality of anchors; said plurality of anchors guided by a plurality of rails; said anchors releasable proximate to a change in curvature of said rails; and a foldable frame configured to position said rails. The system may further be deliverable through a catheter. The flexible member may be adjusted after deployment. The system may further include a guiding frame with features for conforming to anatomical structures
BRIEF DESCRIPTION OF THE DRAWINGS
• In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawings.
• FIG. 1 is a schematic diagram of a treatment system according to one illustrated embodiment, including a medical device with a control handle, tissue anchors, and anchor guiding mechanism
• FIG. 2 is a cutaway diagram of a heart showing a medical device according to one illustrated embodiment percutaneously placed in a left atrium of the heart.
• FIG. 3 is a diagram showing an example of a helical anchor.
• FIG. 4 is a diagram showing an example of a multi-barbed anchor that is encapsulated and an example of a multi-barbed anchor that is not encapsulated.
• FIG. 5 is a diagram showing examples of helical anchors and barbed anchors embedded in tissue
• FIG. 6 is a diagram showing examples of anchors on a guided rail.
• FIG. 7 is a diagram showing an example of a helical anchor on a guided rail penetrating tissue.
• FIG. 8 is a diagram showing an example of a multi-barbed anchor on a guided rail penetrating tissue.
• FIG. 9 is a diagram of an anchor guiding frame according to one illustrated embodiment.
• FIG. 10 is a diagram of an anchor guiding frame compressed into a sheath according to one illustrated embodiment.
• FIG. 11 is a diagram of an expanded anchor guiding frame according to one illustrated embodiment.
• FIG. 12 is a diagram showing the distal end of the medical device according to one illustrated embodiment
• FIG. 13 is a diagram showing an example of anchors secured in a mitral valve annulus.
• FIG. 14 is a diagram showing an example of anchors and a cable used to constrict a mitral valve annulus.
• FIG. 15 is a diagram of a device for securing a cable that constricts a bodily orifice according to one illustrated embodiment.
• FIG. 16 is a diagram of a catheter with side slots according to one illustrated embodiment
• FIG. 17 is a diagram of a mechanism according to one illustrated embodiment for holding a tissue anchor captive
• FIG. 18 is a diagram of a mechanism according to one illustrated embodiment for restricting a tissue anchor from release until said anchor is fully embedded in tissue
DETAILED DESCRIPTION OF THE INVENTION
• In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. However, one skilled in the art will understand that the invention may be practiced without these details. In other instances, well-known structures have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments of the invention.
• Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is as “including, but not limited to.”
• Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
• As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise.
• It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
• The headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed invention.
• Overview of Device and Orifice Constriction Methods
• Various embodiments of medical apparatus which are percutaneously or intravascularly deployed and may be used for constricting a bodily orifice are described herein.
• FIG. 1 shows amedical device100 according to one illustrated embodiment.
• Themedical device100 may be used to deploy tissue anchors107 and aflexible cable111. The tissue anchors107 may be secured to the annulus of an orifice and theflexible cable111 may be used to constrict the orifice by pulling theanchors107 inward. Themedical device100 comprises a flexibleanchor guiding frame108 that may be used to guide tissue anchors107 to target positions on the orifice annulus. The anchor guiding frame may be made of a material such as Nitinol. The guidingframe108 shown inFIG. 1 is comprised of threeguide wires112—one for each of the tissue anchors107 shown. The guiding frame may include a different number of guide wires if more tissue anchors are desired. Theguide wires112 shown preferably have hinges113 and may be connected withsmall loops109. The hinges113 andloops109 enable the guiding frame to fold up to fit inside a catheter and to expand to extend across an orifice. Both thehinges113 andloops109 may be replaced by other mechanisms that enable bending. Themedical device100 typically has an articulatingmechanism106 that enables correctly orienting the anchor guiding mechanism during deployment of tissue anchors107. The articulatingmechanism106 is preferably able to bend in any direction. The control knobs103 and104 may be used to control the bending of the articulatingmechanism106 using cables that are carried in the longflexible tube105.
• Themedical device100 shown comprises a longflexible tube105 which extends from the articulatingmechanism106 to the medicaldevice control mechanism114 located at the proximal end of the catheter.Control mechanism114 may consist ofcontrol knobs103 and104,release rods101, pushtubes102, and guidewires112. Additional controls may be required for other embodiments. Theflexible tube105 may have multiple lumens.Multi-lumen push tubes102, guidewires112,release rods101,cable111, and other mechanisms may be carried inflexible tube105. In the embodiment given, eachpush tube102 has two lumens. Aguide wire112 is carried in a first lumen and arelease rod101 is carried in a second lumen. Anchor s107 are attached distal tips ofrelease rods101. Theanchor107 may be inserted into the annulus of an orifice by advancing thepush tube102 along theguide wire112 and advancing or rotating therelease rod101 carried in thepush tube102 at the same rate. Theanchor107 may advance past thehinge113 and embed into the annulus of the orifice to be constricted. Once theanchor107 is embedded, therelease rod101 attached to the anchor may be retracted while thepush tube102 is held in place. Retraction of therelease rod101 causes theanchor107 to detach from the distal tip of therelease rod101 and remain embedded in the tissue. Other embodiments may use different methods for releasing the tissue anchors107.
• FIG. 2 shows a medical device useful in constricting a bodily orifice, for example a mitral valve, according to one illustrated embodiment.
• The medical device may be percutaneously and/or intravascularly inserted into a portion of theheart212, for example in aleft atrium206 of theheart212. In this example, the medical device is delivered via acatheter202 inserted via theinferior vena cava204 and penetrating thetransatrial septum213 from aright atrium203. Thecatheter202 is preferably under 8 mm in diameter.
• The flexibleanchor guiding frame214 expands after being delivered via thecatheter202 into a shape that preferably enables the tissue anchors207 to be delivered to the desired position on themitral annulus209. The flexibleanchor guiding frame214 may be moved into the correct orientation by adjusting the shape of the articulatingmechanism205, advancing or retractingflexible tube201, or rotatingflexible tube201. The flexibleanchor guiding frame214 preferably has an overall shape that enables said frame to take on a desired orientation within a cavity by conforming to the shape or being affected by the movement of anatomical features. Such a property is known as “self-locating”. Minimal insertion force and operator guidance is typically needed to properly position the anchor guiding mechanism. The flexibleanchor guiding frame214 may also have specific features which cause it to orient correctly based on the position of an anatomical feature, such as themitral valve leaflets211. An example of such a feature is given byalignment fin215.Alignment fin215 is attached rigidly to flexibleanchor guiding frame214 and shaped so that it may be deflected to a particular orientation by an anatomical feature, such asmitral valve leaflets211. As the flexibleanchor guiding frame214 is advanced toward an anatomical feature, such as themitral valve annulus209, the shape or motion of an anatomical feature, such as themitral valve leaflets211, may causealignment fin215, and thus attached flexibleanchor guiding frame214, to rotate or translate to a desired orientation or location.
• Theanchors207 may be inserted into theannulus209 by advancing thepush tubes216 along theguide wires112. Theanchors207 may advance past thebend208 and embed into theannulus209. The embedded anchors207 may then be released from thepush tubes216. Theflexible cable210 connecting theanchors207 may then be tightened and secured to constrict themitral annulus209.
• FIG. 3 shows an example of a tissue anchor according to one illustrated embodiment. Thehelical tissue anchor301 has a helical structure withsharp tip303.Loop302 may be used to connect to a mechanism for holding thetissue anchor301 to a release rod.Loop302 may also be used to attachtissue anchor301 to a cable used for cinching the annulus of a bodily orifice.
• FIG. 4 shows an example of a tissue anchor according to one illustrated embodiment.Tissue anchor403 is shown in a compressed configuration andtissue anchor406 is shown in an expanded configuration. The tissue anchors403,406 comprisemultiple barbs408. Themultiple barbs408 may be compressed into constrictingtube404 as shown fortissue anchor403. Compression ofbarbs408 into constrictingtube404 enables the anchor to move more readily through a catheter and also to be inserted more readily into tissue.
• Tissue anchor403 may comprise ahole409 that may be used to attach said anchor to acable401 used for cinching the annulus of a bodily orifice.Constricting tube404 may comprise aslot402 to allowanchor403 to be ejected from constrictingtube404 in the case wherehole409 is mounted on a protruding flange.
• Tissue anchor406 may comprise ahole407 that may be used to connect said anchor to releaserod405.Release rod405 may be carried in a lumen ofpush tube410. If constrictingtube404 is extended overhole407 as shown foranchor403,release rod405 is held captive inhole407 by the wall oftube404. If constrictingtube404 is retracted to not coverhole407, as shown fortissue anchor406,release rod405 is not held captive inhole407 and said tissue anchor may become disconnected from constrictingtube404 andrelease rod405.
• Tissue anchor406 may be disconnected fromrelease rod405 andbarbs408 may be uncompressed by retracting constrictingtube404 relative to therelease rod405 andtissue anchor406. Retracting constrictingtube404 past the tips ofbarbs408 causes said barbs to be released and expand. Retracting constrictingtube404past hole407 may releasetissue anchor406.
• FIG. 5 shows examples of tissue anchors embedded in tissue.Tissue anchor501 is a helical anchor embedded intissue502.Tissue anchor501 is embedded intissue502 by rotating said anchor.Tissue anchor505 is a multi-barbed anchor embedded intissue502.Tissue anchor505 is embedded intissue502 by pushing the anchor into the tissue.Barbs504 provide resistance to restrict thetissue anchor505 from being extracted.
• FIG. 6 shows examples of anchors guided by a rail.
• Multi-lumen push tube600 may slide overguide rail601.Tissue anchor602 may be temporarily attached tomulti-lumen push tube600 by constrictingtube606 and a release rod (not shown). Slidingpush tube600 alongguide rail601 enablestissue anchor602 to be controllably delivered to a location proximate to guiderail601.Tissue anchor602 may be constructed or oriented in such a way thattissue anchor tip607 slides along or very near to guiderail601. Such orientation or construction enables the tip to be protected from obstructions in the catheter or body that may dull the tip. Also, such orientation or construction protects areas of tissue proximate the guide rail from inadvertent, damaging contact with thesharp tip607 oftissue anchor602.
• Single-lumen push tube603 may slide overguide rail601.Helical tissue anchor604 also may slide overguide rail601 and may be temporarily attached to single-lumen push tube603 bylatch mechanism609.Latch mechanism609 may be fastened to anchor604 by a friction fitting that is released under sufficient axial force. This assembly enablestissue anchor604 to be controllably delivered to a location proximate to guiderail601.Tissue anchor604 may be constructed or oriented in such a way thattissue anchor tip608 slides along or very near to guiderail601. Such orientation or construction enables the tip to be protected from obstructions in the catheter or body that may dull the tip. Also, such orientation or construction protects areas of tissue proximate the guide rail from inadvertent, damaging contact with the sharp tip oftissue anchor608.
• FIG. 6 shows examples of two particular types of anchors being guided by a rail. However, to those skilled in the art, it is apparent that many other types of anchors could also be deployed with the aid of a guide rail as well.
• FIG. 7 shows a helical anchor according to one illustrated embodiment.
• Helical tissue anchor702 is shown partially deployed intotissue708. The location that anchor702 enters the tissue may be determined by the position ofguide rail704.Bend707 inguide rail704 may be positioned at the approximate location where theanchor702 is to be deployed into the tissue.Bend707 inguide rail704 may comprise a hinge, a flexure, or one of many other joints.Tissue anchor702 is deployed by rotatingpush tube703. The rotation oftissue anchor702 at the position of thebend707 causes anchor702 to spiral offguide rail704 and intotissue708.
• Helical tissue anchor705 is shown fully deployed intotissue708, but still connected to latchmechanism709. In the fully deployed position,anchor705 may no longer wrap aroundguide rail704. Whenanchor705 is still connected to latchmechanism709, it may be readily retracted bycounter-rotating push tube703.
• Helical tissue anchor706 is shown fully deployed intotissue708 and disconnected from tolatch mechanism709.Latch mechanism709 may become disconnected fromanchor706 by retractingpush tube703 or releasinglatch mechanism709 with the addition of another cable to trigger a release mechanism.
• FIG. 8 shows an example of a multi-barbed anchor being deployed in tissue according to one illustrated embodiment.
• Multi-barbed tissue anchor805 is shown fully inserted intotissue804, but still encapsulated by constrictingtube809. The location that anchor805 enters the tissue may be determined by the position ofguide rail803. Abend810 inguide rail803 may be positioned at the approximate location where theanchor805 is to be deployed into thetissue804. Thebend810 inguide rail803 may be constructed using a hinge, a flexure, or one of many other methods.Tissue anchor805 is deployed by advancingpush tube802 overguide rail803. Ifanchor805 is encapsulated by constrictingtube809, it may be readily retracted by retractingpush tube802.
• Multi-barbed tissue anchor808 is shown fully inserted intotissue804, but disconnected from constrictingtube811 andrelease rod806.Anchor808 is preferably retracted slightly beforerelease rod806 is disconnected in order to causebarbs807 to expand.Tissue anchor808 may be disconnected fromrelease rod806 andbarbs807 may be expanded by retracting constrictingtube809 relative to therelease rod806 andtissue anchor808. Retracting constrictingtube811 past the tips ofbarbs807 causes said barbs to be released and expand.
• FIG. 9 shows an example of an anchor guiding frame according to one illustrated embodiment.
• Anchor guidingframe901 is used to guide tissue anchors to correct insertion points. Theanchor guiding frame901 shown comprises threeguide rails905, but said frame may comprise more or fewer guide rails. Theanchor guiding frame901 embodiment given shows all guidewires905 connected at the bottom of the frame. An anchor guiding frame is not required to have all guide wires connected together, although it is often preferable to do so to create a framework that enables anchors to be positioned relative to each other and to anatomical features. An anchor guiding frame may have multiple disconnected groups of connected guide wires.
• The anchor guiding frame preferably is capable of folding to enable delivery via a catheter.Guide wires905 may be hinged atbends902 and guidewire connection point904 to enable folding.Loop903 facilitates folding and also acts as a spring to enable unfolding of theanchor guiding frame901.
• Guide wires905 may be formed to havebend906 when no external forces are being applied. Whenguide wires905 are carried in a catheter with an articulating mechanism shaped into a curve as shown inFIG. 2, the forces exerted on the guide wire by the catheter and articulating mechanism will causebend906 to align with the curve in the articulating mechanism. Such alignment causesanchor guiding frame901 to rotate to a desired position relative to the catheter orientation. Bend906 may also be formed to assist in curving the articulating mechanism in a particular way.
• An anchor guiding frame may also contain additional features which use anatomical features or movement to assist in orientation of said anchor guiding mechanism. An example of such a feature is give byalignment fin907.Alignment fin907 is attached rigidly to flexibleanchor guiding frame901 and shaped so that it may be deflected by an anatomical feature, such as mitral valve leaflets, to a particular orientation. As the flexibleanchor guiding frame901 is advanced toward an anatomical feature, such as the mitral valve annulus, the shape or motion of an anatomical feature, such as the mitral valve leaflets, may causealignment fin907, and thus flexibleanchor guiding frame901, to rotate to a desired orientation.
• FIG. 10 shows an anchor guiding frame folded for delivery inside a catheter according to one illustrated embodiment.
• The anchor guiding frame comprisingguide wires1004 may be folded insidecatheter1001.Hinges1006 andloop1007 enhance folding of the anchor guiding mechanism. In the embodiment given, tissue anchors1003 fit between theguide wires1004 in the folded configuration.Protective anchor cap1005 holds and covers the sharp tips of tissue anchors1003 and may ensure that the tips do not catch or embed on the sides ofcatheter1001.Protective anchor cap1005 is held in place bycontrol wire1002
• FIG. 11 shows an anchor guiding frame in an expanded configuration according to one illustrated embodiment.
• Anchor guidingframe1112 may self expand after exitingcatheter1111.Loop1106 may be formed to cause said frame to expand.Hinges1105 facilitate separation of guide wires by about 20 to 45 mm. In the given embodiment, tissue anchors1109 are held within the volume encompassed byanchor guiding frame1112 which ensures theanchors1109 do not accidentally impinge tissue. Also, the tissue anchors tips are held captive withinprotective anchor cap1110. The anchor tips may be released by advancingcontrol wire1103 and thereby also advancinganchor cap1110. The anchor tips are no longer held captive ifanchor cap1110 is advanced sufficiently to a point past the anchor tips. Asguide wires1104 curve away fromanchor cap1110, advancinganchors1109 causes the anchor tips to move away from and avoidanchor cap1110.
• Articulatingmechanism1107 is shown in a curved state. Articulatingmechanism1107 is curved using wires (not shown) that are carried on opposing sides relative to the longitudinal axis of said mechanism and fixed to the distal end of said mechanism. Tensioning one wire causes the articulatingmechanism1107 to arc in the direction of the side of said mechanism said tensioned wire is carried in. Using tensioned wires to curve an articulated joint as indicated is well known. However, for some situations, it is desirable to cause the gaps between links to open at a different rate. For example, when inserting articulatingmechanism1107 into the left atrium, it may be preferable to cause the distal links, such aslink1113 andlink1114, to separate or bend prior to or more than the proximal links, such aslink1115 and1116. One embodiment to enable such an attribute is to insert springs, as indicated by1108 and1102, with varying spring constant k between the links. To cause the distal end of articulatingmechanism1107 to bend first, the distal links should be forced apart by springs with a higher spring constant than the springs between the proximal links. Another embodiment for enabling unequal separation of links is to control the shape of theguide wires1104 that are routed through the articulatingmechanism1107. The guide wires should have a preformed bend with a decreasing radius of curvature in the area fromproximal link1115 todistal link1114.
• FIG. 12 shows the configuration of the tissue anchors and push tubes at the distal tip of the medical apparatus according to one illustrated embodiment. For the sake of clarity,FIG. 12 omits showing guide wires and an anchor guiding frame that would typically be located at the distal tip of the medical apparatus.
• The articulatingmechanism1204 may comprisemultiple lumens1208 through whichpush tubes1202 are carried. In this particular embodiment, threelumens1208 are shown, but other embodiments may comprise more or less. Pushtubes1202 may also comprise multiple lumens. In this particular embodiment, eachpush tube1202 has alumen1201 in which a guide wire may be carried and a second lumen that carries the release rod (not shown) which is connected to the tissue anchors1209.Constricting tubes1205 may be mated into the distal end of said second lumen. All tissue anchors may be connected byflexible cable1207. The flexible cable may also be carried within a separate lumen within the articulatingmechanism1204.Lumens1203 are used to carry cables that control the curvature of the articulatingmechanism1204.
• FIG. 13 shows a cross section of the heart with an anchor guiding frame according to one illustrated embodiment positioned within the left atrium.
• Anchor guidingframe1303 is shown self-located on themitral annulus1304 within the left atrium. The tissueanchor deployment sites1301 are preferably located on the mitral annulus and coincident with bends in the guide rails1302.FIG. 13 shows threeguide rails1302 andtissue deployment sites1301 for simplicity; however, in many cases more deployment sites and guide rails are desirable. In such cases, it is a simple matter to add additional guide rails and anchor deployment sites to the disclosed embodiment.
• Alignment fin1305 may fit betweenmitral valve leaflets1306. The movement and anatomical structure of themitral valve leaflets1306 exert force onalignment fin1305 and assist in orienting theanchor guiding frame1303 correctly
• FIG. 14 shows a cross section of the heart with an installed assembly capable of constricting the mitral valve annulus according to one illustrated embodiment.
• Tissue anchors1401,1402, and1403 are shown fully deployed on themitral annulus1406. Tissue anchors may be connected byflexible cable1405. Other mechanisms for connecting tissue anchors1401,1402,1403 are possible. For example, rigid members, preferably with adjustable length, may be used to connect said anchors.Flexible cable1405 may slide through holes on the tissue anchors1401,1402,1403.
• Flexible cable1405 may pass through ahollow spreader bar1404.Hollow spreader bar1404 provides support to keeptissue anchors1401 and1403 from moving closer together whenflexible cable1405 is shortened. Such support reduces undesired forces being applied to theaortic valve1407.
• Reducing the distance between tissue anchors1401,1402 and1402,1403 causes the anterior-posterior (A-P) annular dimension of the mitral valve to reduce and improves leaflet coaptation. Several methods may be used to reduce the distance between tissue anchors. A first method is to shorten the cable during the installation procedure by routing theflexible cable1405 throughfastener1408, pulling the cable manually to be as tight as desired and crimpingfastener1408.Fastener1408 may also be constructed using a one way clutch so that theflexible cable1405 can only be pulled through in one direction, in which case crimping is not required. A second method of reducing anchor separation is to include shorteningactuator1409 between two anchors. In the case where shorteningactuator1409 is included,flexible cable1405 is split and attached to either end of the shortening actuator. One embodiment of shorteningactuator1409 contains an element that is capable of changing length as a response to changes in an external magnetic field or in response to heating induced by a changing magnetic field. The element capable of changing lengths may be made of a highly magnetostrictive alloy such as Terfenol-D or from a Shape Memory Alloy (SMA) such as specially treated Nitinol. Embodiment of such actuators are described in U.S. Ser. No. 11/902,199. The element capable of changing lengths may be made of a spring under tension encapsulated in material that melts under low heat and solidifies at body temperature—such as a thermoplastic polymer. Current induced in a loop by an external magnetic field may be channeled through the spring. The current may heat the spring which will cause the polymer to soften and the spring length to contract. The contraction of the spring can be used to reduce the separation of the tissue anchors. Embodiments of such actuators are described in U.S. Ser. No. 11/905,771.
• A closed, electrically conducting loop is required if shorteningactuator1409 is to be responsive to heating or energy induced by a changing magnetic field. Such a loop may be achieved by using an electrically conductive material forflexible cable1405 and ensuring an electrical contact between both ends offlexible cable1405 that are connected to shorteningactuator1409.
• FIG. 15 shows a cross section of a tool and fastener used to tighten and secure a cable according to one illustrated embodiment.
• Fastener1507 may be used to tighten or secure cables being used to constrict a bodily orifice. Typically prior to attachment offastener1507, tissue anchors have been placed, and a flexible cable has been connected to the tissue anchors.Cable end1504 andcable end1503 are typically carried incatheter sheath1505 and routed outside the body.Cable end1504 andcable end1503 may be the two ends of one flexible cable. The portion of the cable not shown loops around the orifice to be constricted and is attached to the implanted tissue anchors used to secure the cable to the orifice.
• Cable end1504 may be fed intohole1511 and locked byferrule1510 whilefastener1507 is still outside the body.Cable end1503 may be routed throughtaper lock1509 whilefastener1507 is still outside the body.
• Fastener1507 may be attached tofastener positioning tube1506.Cable end1503 may be inserted throughslot1502 and intofastener positioning tube1506.Fastener1507 andfastener positioning tube1506 may be inserted intocatheter sheath1505 and advanced untilfastener1507 is proximate the annulus of the orifice to be constricted.Cable end1503 may be pulled in a direction away fromfastener1507, causing the cable to pull throughtaper lock1509 and constrict the orifice. While the cable is being tightened and secured,fastener1507 may be held byfastener positioning tube1506.Taper lock1509 restrictscable end1503 from being pulled out the right side offastener1507.Taper lock1509 may haveteeth1515 to gripcable end1503.Taper lock1509 may have a longitudinal slot to enable compression oftaper lock1509 and constriction aroundcable end1503.Spring1508 may forcetaper lock1509 into aconical hole1514, causing it to tighten aroundcable end1503.
• When the orifice has been sufficiently constricted,cable end1503 may be severed usingcable cutting tube1501.Cable cutting tube1501 comprises a sharpenedend1516.Cable cutting tube1501 is shown in a retracted position. The cable cutting tube may slide inside offastener positioning tube1506.Cable cutting tube1512 is shown in the cable cutting position.Cable cutting tube1512 may severcable end1513 by forcingcable end1513 against the end ofslot1516. The cable end may be severed in other ways, including using a hot tip to melt through the cable.
• FIG. 16 shows a catheter with grooves, or side slots, and a mechanism for securing cables or wires in said side slots according to one illustrated embodiment.
• Catheter1604 is shown withcables1601 held withinlongitudinal groove1603 on the inner surface of the tube wall bytube1602. Thelongitudinal groove1603 has a cross sectional shape that enablestube1602 to be held captive.FIG. 16 shows a circular groove, but other shapes may be used.Tube1602 carriescables1601.Tube1602 could also carry wires or tubes. Whentube1602 is removed by pulling it out the end, as shown bycatheter1607,cables1605 are free to move into the central area of the tube.Tube1602 can be reinserted overcables1605 to again constrain them ingroove1603.
• AlthoughFIG. 16 showscatheter1604 andcatheter1607 with only onegroove1603, it is possible to have many such grooves in a catheter and to secure a plurality of wires and tubes in said grooves. One of the reasons for securing cables or wires in grooves, or side slots, is to eliminate tangling of cables or wires during medical procedures.
• FIG. 17 is a cross sectional diagram of a mechanism for holding a tissue anchor captive according to one illustrated embodiment
• Tissue anchor1703 may be held captive in constrictingtube1706 byrelease rod1704.Constricting tube1706 may be inserted and secured to the distal end of one lumen ofpush tube1701.Constricting tube1706 may be held captive in the lumen byribs1705.
• Tissue anchor1703 may be released from constrictingtube1706 by retractingpush tube1701 and constrictingtube1706 relative to releaserod1704. As the distal end of constrictingtube1706 clearshole1707,release rod tip1708 will pop out ofhole1707 andtissue anchor1703 will no longer be held captive.
• Lumen1702 ofpush rube1701 may be used to slide over a guide wire.
• FIG. 18 is a cross sectional diagram of a mechanism for restricting a tissue anchor from release until anchor is fully embedded in tissue according to one illustrated embodiment
• An additional benefit is provided if the medical device for constricting a bodily orifice does not release tissue anchors until they are fully embedded in the tissue. It is possible to achieve this benefit by adding anadditional latch1806,1810 to the medical device.
• Tissue anchor1802 is shown prior to deployment.Tissue anchor1802 may not be released from constrictingtube1805 by retractingpush tube1803 and constrictingtube1805 relative to releaserod1804 becauselatch1806 protrudes intonotch1801.
• Tissue anchor1808 is shown fully deployed intotissue1812. Astissue anchor1808 was deployed intotissue1812, the surface oftissue1812 causeslever1811 to bend. Whenlever1811 is bent,latch1810 clearsnotch1813. Oncelatch1810 clearsnotch1813,tissue anchor1808 may be released from constrictingtube1809
• The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the invention can be modified, if necessary, to employ systems, circuits and concepts of the various patents, applications and publications to provide yet further embodiments of the invention.
• These and other changes can be made to the invention in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims, but should be construed to include all medical treatment devices in accordance with the claims. Accordingly, the invention is not limited by the disclosure, but instead its scope is to be determined entirely by the following claims.

Claims (20)

1. A method for constricting a bodily orifice or cavity, the method comprising:

Delivering a plurality of anchors to the bodily orifice or cavity intravascularly;

Implanting the plurality of anchors;

Connecting the plurality of anchors by at least one joining member;

Contracting at least one joining member.

2. The method ofclaim 1 wherein the bodily orifice is a mitral valve

3. The method ofclaim 1 wherein the at least one joining member is a flexible cable

4. The method ofclaim 1 wherein the anchors comprise a helical portion

5. The method ofclaim 1 wherein the anchors comprise multiple barbs

6. The method ofclaim 1 wherein the plurality of anchors are guided to implant sites by means of at least one guide rail

7. The method ofclaim 6 wherein the plurality of anchors are released proximate to a change in curvature of the guide rail.

8. The method ofclaim 7 wherein at least two guide rails are distally connected.

9. A medical system for constricting an orifice comprising a device positionable in at least a portion of a bodily organ;

a plurality of guide rails;

a plurality of anchors releasably guided by said guide rails;

at least one structure used to locate said guide rails;

means of connecting said anchors;

means of shortening or bending said connecting means.

10. The medical device ofclaim 9 wherein the medical system is deployed intravascularly

11. The medical device ofclaim 9 wherein the portion of a bodily organ is a left atrium of a heart

12. The medical device ofclaim 9 wherein the plurality of anchors are released proximate to a change in curvature of said guide rails

13. The medical device ofclaim 9 wherein the plurality of anchors are held captive within a cap prior to deployment

14. The medical device ofclaim 9 wherein the plurality of anchors are not released from said guide rails until implanted

15. The medical device ofclaim 9 wherein the connecting means is shortened by application of a external magnetic field

16. The medical device ofclaim 9 wherein said structure is foldable into a catheter

17. A medical system for attaching a flexible member to tissue comprising

A flexible member attached to tissue by a plurality of anchors;

Said plurality of anchors guided by a plurality of rails;

Said anchors releasable proximate to a change in curvature of said rails;

A foldable frame configured to position said rails.

18. The medical system ofclaim 17 wherein said medical system is deliverable through a catheter

19. The medical system ofclaim 17 wherein said flexible member is adjusted after deployment

20. The medical system ofclaim 17 wherein said frame comprises features for conforming to anatomical structures

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