US20180325523A1 - Devices and methods for ligating anatomical structures - Google Patents

Abstract

Devices and methods for ligating anatomical structures are provided herein. In particular, the devices and methods provided herein can be used to ligate the left atrial appendage. The ligating devices (10, 110, 210, 310, 410) comprise a ligating element (30, 130, 230, 330, 430) and a control element (40, 140, 240, 340, 430) which controls the opening of the ligating element in a loop or lariat shape. Some embodiments comprise also a positioning element (50, 150) which help position the ligating element. In some embodiments a conduit (250) is provided for displaying the ligating element by inflating control.

Description

RELATED APPLICATIONS
• This application claims the benefit of U.S. Provisional Patent Application No. 60/826,413, filed on Sep. 21, 2006 and titled DEVICES AND METHODS FOR LIGATING ANATOMICAL STRUCTURES, which is hereby incorporated by reference in its entirety.
• The present invention relates to devices sad methods for ligating anatomical structures such as, e.g., the left atrial appendage.
• Atrial fibrillation is a common cardiac rhythm disorder affecting mere than two million people each year, in which the upper part of the heart beats more quickly than the rest of the heart. This phenomenon is dye. to the generation of erratic or extra electrical signals that cause the top part of the heart to fibrillate rapidly and irregularly. The adult human heart normally beats 60 to 80 times per minute at rest. With atrial fibrillation, the heart can heat as many as 300 to 600 times a minute.
• One of the most significant dangers from atrial fibrillation is stroke. In fact, atrial fibrillation can make stroke as much as five times more likely than in the general population. Since the heart does not pump normally or efficiently during atrial fibrillation, blood can pool and stagnate in the atria, resulting in clot formation.
• Blood pooling and clot formation is especially likely to occur in the left atrial appendage (LAA). The LAA is a hollow, pedunculated extension that resembles a small windsock fanned off the lateral wall of the left atrium. The LAA usually contracts with the rest of the left atrium during normal heart function, thereby continually moving blood throughout the hollow extension. During atrial fibrillation, however, the LAA often fails to contract, thereby allowing blood to pool and stagnate inside the appendage. As a result, thrombus or clot formation can occur. Such clots can be ejected from the LAA into the left atrium and left ventricle, and then can be released into the bloodstream to become potential obstructions in the brain or in other vascular structures.
SUMMARY
• The present invention provides methods and devices for ligating anatomical structures, where anatomical structures include both those that are purely anatomical and those that are pathological, in some instances, the structures are ligated. to, e.g., reduce or prevent Mood dot formation in and release from a structure such as the LAA. These methods and devices can be used to ligate the LAA, thus preventing Mood from entering the appendage, pooling, and forming dots, ligation of the LAA also can prevent or reduce the escape of previously formed clots into the bloodstream. The methods and devices provided herein can facilitate minimally invasive treatment for atrial fibrillation. These methods can be performed in conjunction with other procedures (e.g., mitral valve replacement, radio frequency ablation, atrial fibrillation ablation, coronary artery bypass, etc.) or they can be performed solely to ligate the anatomical structure (such, as the LAA).
• Although the exemplary devices and methods described herein focus on ligation of the LAA, the devices and methods of the present invention can be useful for ligation of other anatomical structures, including, e.g., the gallbladder, the GI appendage, diverticula fallopian tubes or ovaries, vascular aneurysms, or any other pedunculated structure or mass. The devices can be used in any laparoscopic or minimally invasive surgery in which it would be useful to ligate, tie, or clip a structure via a single port access.
• In one aspect, the present invention provides a ligating device that includes a catheter having a proximal end and a distal end; a ligating element located within the catheter, wherein the ligating element includes a lumen and a first end and a second end, wherein the first end and the second protrude from the proximal end of the catheter; and a control element located within, the lumen of the ligating element, the control element including a first end that protrudes from the first end of the ligating element, wherein a distal portion of the control element forms an open loop upon exit from the distal end of the catheter, and wherein the open loop is compressed when the distal portion of the control element is located within the catheter, and further wherein the control element forces the ligating element to adopt a lariat configuration when outside of the catheter.
• In various embodiments, the ligating devices described herein may include one or more of the following features: the control dement may be removable, such that the control element can be pulled out of the lumen of the ligating element; the control element may include a second end that protrudes from the lighting element; a portion of the ligating element may include a knot formed therein; the control element may extends through the portion of the ligating element that deludes a knot; and the control element may include a distal portion and a proximal portion, and the distal portion may be thinner than the proximal portion; the ligating element may be a hollow suture and the control element may include shape memory material; the lariat may be formed at an angle with respect to an elongate portion of the control element from which the lariat extends; the control element may include an angled portion when the control element is located outside of the catheter; a positioning element may be attached to the lariat of the ligating element; the ligating device may include an appendage positioning element; the control element may include magnetizable material such that the position of the ligating element can be manipulated by a magnetic device; and a sheath may be provided in which the catheter is located; etc.
• In still other embodiments, the ligating devices may include one or more of the following features; the ligating element may include a knot formed therein and the control element may have a distal end that is located distal from the knot; a secondary control element may be located within a portion of the ligating element, wherein a distal end of the second control element may be located proximal from the knot such that the second control element does not extend through the knot; etc.
• In another aspect, the present invention may provide a ligating device that includes a catheter having a proximal end and a distal end; an elongate element located within the catheter, the elongate element having a proximal end and a distal end; a ligating element located within the catheter, wherein the ligating element is attached to the distal end of the elongate element, and further wherein the ligating element comprises an original shape of a closed loop; a control element located within the catheter, the control element including a first end that protrudes from the proximal end of the catheter, wherein a portion of the control element is contained within the ligating element, wherein pulling on the first end of the control element opens the ligating element from its original closed loop shape to open the ligating element into a lariat configuration. The ligating element may be rotatably attached to the elongate element.
• In another aspect, the present invention may provide a ligating device that includes a catheter having a proximal end and a distal end; an elongate element located within the esthetes; the elongate element having a proximal end and a distal end; a ligating element located within the catheter, where m the lighting dement is attached to the distal end of the elongate element, and further wherein the legating element includes a ring clip whose natural position is closed; a hollow control element attached to the lighting element; and a conduit in fluid communication with the hollow control element, wherein the conduit extends to the proximal end of the catheter, wherein pressurized fluid delivered to the control element inflates the control dement to open the lighting element. The ligating device may further include one or more of the following features: the control element may be located inside or outside of the ligating element; the conduit may be located within the elongate element; a source of pressurized fluid may be in fluid communication with the conduit; etc.
• In another aspect, the present invention may provide a ligating device that includes a catheter having a proximal end and a distal end; a control element located within the catheter, wherein the control element has an elongate U-shape with both ends protruding from the proximal end of the catheter and the bottom of the U-shape positioned near the distal end of the catheter; and a ligating element attached to one end of the control element; wherein the end of the control element that is not attached to the ligating element can be pulled to advance the ligating element through the catheter. The ligating device may include a tubular sheath surrounding a portion of the control element at the distal end of the catheter, wherein advancing the ligating element also advances the ligating element through the tubular sheath.
• In another aspect, the present invention provides a ligating device that includes a catheter having a proximal end and a distal end; a control element located within the catheter, the control element having a first elongate portion located within the catheter, the first elongate portion including a proximal end and a distal end, wherein the control element further includes a second elongate portion located within the catheter, the second elongate portion having a proximal end and a distal end; and a ligating element attached to the distal ends of the first elongate portion and the second elongate portion, wherein manipulation of the first elongate portion and the second elongate portion cause the ligating element to form a lariat.
• In another aspect, the present invention provides a method of ligating an anatomical structure that includes advancing a ligating device as described herein to a selected anatomical structure; and operating the ligating device to ligate the selected anatomical structure.
• In another aspect, the present invention provides a tissue piercing device that Includes a hollow sheath; and a wire disposed within the hollow sheath, wherein the wire includes a distal end configured to coil after being deployed out of the sheath. The tissue piercing device may further include a hollow needle contained within the hollow sheath, wherein the wire is disposed within the hollow needle.
• In another aspect, the present invention provides a tissue piercing device that includes a hollow sheath; and a wire disposed within the hollow needle, wherein the wire includes an RF tip at its distal end. The tissue piercing device may further include a hollow needle contained within the hollow sheath, wherein the wire is disposed within the hollow needle.
• In another aspect, the present Invention can provide a device that includes a hollow flexible catheter having a proximal end and a distal end; an elongate ligating element disposed within the catheter, wherein the ligating element has a first end and a second end that protrude from the proximal end of the catheter; and an elongate control element disposed within the ligating element, wherein the control element has a first end and a second end that are positioned toward the proximal end of the catheter, wherein at least one of the first and second ends of the control element protrudes from an end of the ligating element, wherein the control element comprises shape memory materials and wherein at least a portion of the control element is shaped to form an open loop upon exit from the distal end of the catheter.
• The ligating element can be in the form of a hollow suture. The suture can include materials such as, e.g., PTFE, polyethylene, or polypropylene. The control element can include shape memory materials such as, e.g., Nitinol. The loop formed by the control element can be at an angle with respect to another portion of the control element. The control element can further form an angled section upon exit from the distal end of the catheter. The device cars potentially have a length between about 12 inches and about 60 inches (e.g.,, between about 36 inches and about 48 inches). The device can potentially have a diameter between about 0.05 cm and about 3 cm (e.g., between about 0.1 cm and about 0.4 cm). The device can further Include a positioning element disposed within the catheter, a sheath in which the catheter is disposed, and/or an appendage positioning element.
• In another aspect, the present invention can provide a device that includes a hollow flexible catheter having a proximal end and a distal end; an elongate element disposed within the catheter, wherein the elongate element has a proximal end extending from the proximal end of the catheter and distal end positioned near the distal end of the catheter; a rigid ligating element attached to the distal end of the elongate element, wherein the ligating element includes shape memory material configured in a closed loop; and a flexible control element disposed within the catheter and contained within at least a portion of the ligating element, wherein the control element has a first end and a second end, wherein at least one of the first and second ends of the control element protrudes from the proximal end of the catheter.
• The ligating element can include a shape memory material such as, e.g., Nitinol. The ligating element can be rotatably attached to the elongate element. The ligating element and the elongate element can be attached via a pin, about which the ligating element can rotate with respect to the elongate element. The ligating element can include atraumatic material (e.g., PTFE or DACRON™). The control element can include, e.g., a suture, a string, a flexible wire, etc. The device can, e.g., have a length between about 12 inches and about 60 inches (e.g., between about 36 inches and about 48 inches). The device can, e.g., have a diameter between about 0.05 cm and about 3 cm (e.g., between about 0.1 cm and about 0.4 cm). The device can further include a positioning element disposed within the catheter, a sheath in which the catheter is disposed, and/or an appendage positioning element.
• In another aspect, the present invention may provide a device that includes a hollow flexible catheter having a proximal end and a distal end; an elongate element disposed within the catheter, wherein the elongate element has a proximal end extending from the proximal end of the catheter and a distal end positioned near the distal end of the catheter; a flexible, hollow, donut-shaped control element attached to the distal end of the elongate element, wherein the control element has an outer surface and an inner lumen; and a rigid ligating element contained within or positioned around the ligating element, wherein the ligating element includes shape memory material and is in the form of a closed loop.
• The elongate element can define a lumen between the proximal and distal ends, and wherein the lumen of the elongate element is in fluid communication with the lumen of the control element. The control element can include, e.g., PTFE, polyethylene, or polypropylene. The ligating element can include shape memory materials such as, e.g., Nitinol. The device can, e.g., have a length, between about 12 inches and about 60 inches (e.g., between about 36 inches and about 48 inches). The device can, e.g., have a diameter between about 0.05 cm and about 3 cm (e.g., between about 0.1 cm and about 0.4 cm). The device can further include a positioning element disposed within the catheter, a sheath in which the Catheter is disposed, and/or an appendage positioning element.
• In still another aspect, the present invention may provide a device that includes an elongate, hollow, flexible sheath having a tapered distal end; an elongate, hollow needle disposed within the sheath; and an elongate wire disposed within the needle. The wire can have a distal end, and may include a radiofrequency electrode at the distal end. The hollow needle can have a curved distal end. The device can further include means for advancing a portion of the wire out of the distal end of the sheath. The wire can have a distal end configured to coil after being advanced out of the distal end of the sheath.
• The present invention may also provide a method for accessing the pericardial space of a subject. The method can include passing a device as described herein through the circulatory system and into the left coronary sinus of the subject; and piercing the wall of the coronary sinus or coronary venous system of the subject to access the pericardial space.
• In another aspect, the -present invention may provide a method for ligating the left atrial appendage in a subject. The method can include advancing the distal end of a ligation device as described herein into the chest of the subject; placing the distal end of the device within the pericardium of the subject; and positioning the ligating element around the base of the left atrial appendage. The distal end can be advanced into the chest of the subject via a suprasternal, intercostal, or sub-xiphoid approach. The distal end can also be advanced through the coronary sinus or one of its tributaries into She pericardial space.
• Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
• The words “preferred” and “preferably” as used herein refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention.
• As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably. Thus, for example, a ligating element can include one or more ligating elements The term “and/or” means one or all of the listed elements or a combination of any two or more of the listed elements.
• The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTIONS OF THE DRAWINGS
• FIG. 1 is a cross-sectional view of the distal portion of a ligating device having a catheter with a hollow suture ligating element and a control element contained within the hollow suture ligating element, where the ligating and control elements are in a closed configuration.
• FIG. 2 is a cross-sectional view of the distal portion of the device shown inFIG. 1, wherein the ligating and control elements are in an open configuration, forming a lariat or loop.
• FIG. 3 is a cross-sectional/perspective view of the distal portion of a device having a lariat or loop oriented at an angle relative to the elongate portion of the ligating and control elements.
• FIGS. 4A and 4B are cross-sectional/perspective views of the distal portion of devices having a lariat or loop oriented at an angle relative to the elongate portion of the ligating and control elements, and further having an elongate element with an angled portion.
• FIGS. 5A and 5B are cross-sectional views of the distal portion of devices having a catheter with a ligating dement and a control element contained therein, and further having an outer sheath with a positioning element contained therein. The positioning element is shown at the base of the lariat or loop (FIG. 5A) or at the distal end of the lariat or loop (FIG. 5B).
• FIG. 6 is a cross-sectional/perspective view of the distal portion of a device as shown inFIG. 3, where the device further includes an appendage positioning device contained within the catheter.
• FIG. 7 is a cross-sectional view of the distal portion of the de vice as shown inFIG. 2, further depicting removal of the control element.
• FIG. 8 is a cross-sectional view of the distal portion of the device as shown inFIG. 2, further depicting a knot in the ligating element.
• FIG. 9 is a cross -sectional view of the distal portion of the device as shown inFIG. 8, where the knot is advanced to the base of the lariat and the lariat is in a tightened configuration.
• FIG. 10 is a cross-sectional view of the distal port ion of the device as shown inFIG. 9, further including a repositioning element and depicting loosening of the knot.
• FIG. 10A is a cross-sectional view of a ligating device in which the control element is positioned through a knot formed in the ligating element.
• FIG. 10B is a cross-sectional view of a ligating device in which two control elements are positioned in the ligating element.
• FIG. 11 is a side view of the distal portion, of a device having a catheter and a rigid ligating element, where the ligating element is connected to an elongate element contained within the catheter, and further having a control element extending through the catheter and the ligating element. As shown, the ligating element is in a closed configuration.
• FIG. 12 is a cross-sectional view of the distal portion of the device depicted inFIG. 11, with the ligating element in a closed configuration.
• FIGS. 13A and 13B are cross-sectional views of the distal portion of devices having a control element extending through the entire ligating element (FIG. 13A) or through a portion of the ligating element (FIG. 13B), with the ligating element shown in an open configuration.
• FIG. 14 is a side view of a portion of the distal end of the device depicted inFIG. 13, where the device further includes a positioning element.
• FIG. 15 is a side view of a portion of the distal end of the device depicted inFIG. 13, where the device further includes a positioning element, and where the ligating element is at an angle with respect to the elongate element.
• FIG. 16 is a cross-sectional view of the distal portion of a device having a catheter containing an elongate element, with a hollow control element connected to the elongate element, and a rigid ligating element contained within the hollow control element. The control and ligating elements are shown in a closed (e.g., uninflated) configuration.
• FIG. 17 is a cross-sectional view of the distal portion of the device shown inFIG. 16, where the control and ligating elements are in an open (e.g., inflated) configuration.
• FIG. 18 is a cross-sectional view of the distal portion o f the device shown inFIG. 17, where the device further includes a positioning element.
• FIG. 19 is a cross-sectional view of the distal portion of a device having a control element that includes two substantially rigid elongate portions, and a flexible ligating element attached to the distal ends of the elongate portions.
• FIG. 20 is a cross-sectional view of the distal portion of the device ofFIG. 19, where the elongate portions of the control element have been manipulated such that the flexible ligating element forms a lariat.
• FIG. 21 is a cross-sectional view of the distal portion of a device having a catheter, a control element, and a protective sheath.
• FIG. 22 is a cross-sectional view of the distal portion of the device ofFIG. 21, with the control element pulled through the catheter such that a ligating element connected to the control element is advanced through the protective sheath.
• FIG. 23 is a cross-sectional view of the distal portion of a device for accessing the pericardial space through the coronary sinus (CS).
• FIG. 24 is a side view of the distal end of a wire that coils when deployed through the CS wall.
• FIG. 25 is a cross-sectional view of the distal portion of the device ofFIG. 23, having a needle with a curved distal end.
• FIG. 26 is a cross-sectional view of the distal portion of the device shown inFIG. 25, further including a balloon connected to a fluid conduit
• FIG. 27 is a cross-sectional view of the distal portion of She device ofFIG. 25, having a wire with a radiofrequency (RF) electrode at its tip.
• FIG. 28 is a cross-sectional view of the distal portion of a device for accessing the pericardial space through the CS, where the device contains a catheter having suture needles disposed therein.
• Like reference symbols in the various drawings indicate like elements.
DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION
• The devices and methods provided in connection with the present invention can be used to ligate anatomical structures such as. e.g., the LAA and other anatomical features. Although, the exemplary embodiments described herein are discussed in the context of LAA ligation, the devices and methods of the present invention should not be limited to that use. Ligation of anatomical structures may be performed for a variety of reasons. Ligation of the LAA may, for example, reduce the likelihood of or prevent clots from forming in the LAA and/or reduce the likelihood, of or prevent previously formed clots from escaping into the bloodstream.
• In general, the ligating devices of the present invention may include a ligating element and a control element. The control element can be contained within the ligating element or the ligating element can be contained within the control element In other embodiments, the ligating element can be separate from the control element. For example, the ligating element can encircle the control element, or vice versa, or an end of the ligating element (e.g., a length of suture) can be attached to an end of the control element (e.g., a length of wire), such that neither element is contained within the other.
• The ligating element, the control element, or both the ligating element and the control element can be contained within the lumen of a catheter having proximal and distal ends, with the lumen defined therebetween. At least a portion of the ligating element and/or at least a portion of the control element can be positioned at the distal, end of the catheter. In some embodiments, the ligating element and/or the control element can extend through the length of the catheter. In other embodiments, the ligating element and/or the control element can be positioned at the end (e.g., the distal end) of a separate elongate element, such that the elongate element extends through the length of the catheter and the ligating and/or control elements are positioned at the distal end of the catheter. For example, in some eases the ligating element can be positioned at the distal end of an elongate element within the catheter, and the control element can extend through all or a portion of the ligating element and through the length of the catheter.
• The ligating element can be adapted for placement around the LAA (e.g., the base of the LAA) or other anatomical structure, such that the LA A can be effectively closed off from the left atrium. The control element can be adapted to facilitate placement of the ligating element in the desired position around the LAA. Typically, at least one of the ligating element or the control element can be constructed to be rigid arid/or to have shape memory, such that the ligating element and/or control element can have a closed configuration tor passage through the catheter and eventual tightening around the base of the LAA, and an open “lariat” configuration for placement over and around the body of the LAA.
• The lariat formed by the ligating element and/or control element in the open configuration can have any suitable shape and size. For example, a lariat can have an essentially circular or oval shape, or can have an irregular shape to, for example, follow the curve of the heart. A lariat can have a maximum diameter from, e.g., about 0.5 cm to about 4 cm ( e.g., from about 0.7 cm to about 3.5 cm, from about 1.0 cm to about 2.5 cm, or from about 1.5 cm to about 2.0 cm).
• The ligating devices provided in connection with the present invention may be readily deployed In a percutaneous manner. In addition, the ligating devices can be adapted to minimize trauma to the tissue they contact such that there is little or no erosion through the tissue, reducing, the likelihood of bleeding and cardiac tamponade. Further, the devices can be reversible and/or repositionable, such that a clinician can position the ligating element over the LAA, tighten the ligating element around the LAA, and then loosen, and reposition the ligating element if desired.
• In some embodiments, a ligating device can have a hollow ligating element formed of a soft, pliable material (e.g., polytetrafluoroethylene (PTFE), polyethylene, polypropylene, or any other suitable material), and an inner control element formed of a more rigid material (e.g., wire, etc.) or any other suitable material that can provide the hollow element with at least temporary rigidity (e.g., pressurized fluid such as water or air).
• For example, a ligating element can be in the form of a hollow (e.g., PTFE) suture, with a control element running through the lumen of the hollow suture. The wire loaded Suture can have a generally elongate “U” shape and can extend through the length of the catheter, with both ends protruding from the proximal end of the catheter and the bottom of the “U” positioned at or near the distal end of the catheter. The distal end of the device can be positioned near the LAA (or other anatomical structure) via any suitable approach (e.g., via sub-xyphoid, intercostal, or trans-coronary sinus approach for the LAA). The ligating element can be passed through the distal end of the catheter and placed around the base of the LAA.
• In some embodiments, the inner control element can be made of a shape memory material (e.g., Nitinol), such that when the hollow ligating element exits the distal end of the catheter it assumes an open “lariat” configuration to facilitate placement around the LAA or other anatomical structure. The inner control element, may also give the ligating element a configuration that places (orients) the lariat at an angle with respect to the elongate portion of the ligating element, to further facilitate positioning of the device over the LAA or other anatomical structure. In some embodiments, the control element can be configured such that as the ligating element is progressively extended out of the distal end of the catheter, the shape and angulation of the lariat changes. The angulation and shape of the ligating device can, in some embodiments, be tailored based on patient anatomy Angled configurations of the control element can provide additional control of the lariat, to further facilitate positioning of the device.
• In addition, a ligating device provided in connection with the present invention may include a separate positioning element, which also can be used to position and reposition or remove the ligating element if desired. A clinician also can manipulate either or both ends of the inner control element to alter the shape and/or position of the ligating element In some embodiments, the control element can contain a magnetizable material (e.g., iron, nickel, cobalt, gadolinium, dysprosium, or composites of flexible resins and magnetic powders, with or without a binder such as vinyl), and the position of the ligating element can be manipulated by a magnetic device outside the body (e.g., a magnetic navigation system from, for example, Stereotaxis, Inc. of St. Louis, Mo.).
• Once placed, the ligating element can be retained in position via a clip or any other suitable means. The control element can be removed if desired (e.g., by pulling on one end of the control element such that it slides out of the lumen in the ligating element). Once the control element is removed, the ligating element can be tightened to close the LAA and then fixed in position via a clip, a knot, or any other suitable fastening means.
• If a knot is used, the knot can be tied outside the body and pushed through the catheter into position to close the LAA. Examples of suitable knot pushing devices and methods are described in, for example, U.S. Pat. Nos. 6,132,439, 5,759,189, and 5,769,863. A knot pushing device can be made from a substantially rigid material, from a flexible material (e.g., polypropylene or polyethylene), or from a combination of flexible and rigid materials.
• In some embodiments, a ligating device of the present invention can have a ligating element formal of a rigid material (e.g., shape memory material such as Nitinol, etc.), and an inner or outer control element formed of a pliable material (e.g., suture, soft wire, or any other suitable material). The ligating element can be positioned at the end of an elongate element that extends through the length of the catheter, such that the ligating element can be positioned at or toward the distal end of the device, within the lumen of the catheter.
• The rigid (e.g., shape memory) material of the ligating element can be covered on its exterior surface with a coating (e.g., PTFE, DACRON™, or other suitable material) to, for example, prevent tissue trauma. Examples of suitable coatings are described elsewhere (e.g., U.S. Publication No. 2005/0277959).
• In some cases, the natural position or configuration of the ligating element can be closed. Such a position or configuration can facilitate passage of the ligating and control elements through the catheter, and can provide a ready means to close off the LAA after placement of the ligating element.
• An inner control element can extend through the entire length of the ligating element or through a portion of the ligating element. An outer control element can extend around (e.g., encircle) the entire ligating element, or can foe attached to a portion of the ligating-element. In some embodiments, a control element can be secured at or near the distal end of the ligating element.
• In use, a clinician can pull on the control element in the proximal, direction, opening the ligating element into a lariat configuration to allow for positioning of the device over the LAA. In some cases, an inner control element extending through the entire length of a ligating dement may not be secured within the ligating element, but can be configured such that a clinician can apply force in the proximal direction (e.g., by pulling on both ends of the control element) to open the ligating element. The ligating element can have a pre-formed shape that, for example, facilitates opening of the lariat upon actuation of the control element. For example, a ligating element containing a shape-memory material can have a preformed shape with preferential bends to facilitate formation of a lariat.
• In some eases, a portion of the ligating element (e.g., at a point on the base of one side of the ligating element) can be affixed to the distal end of the catheter or the sheath. In these cases, the control element can be actuated (e.g., pulled in the proximal direction) such that the unaffixed side of the ligating element can move into the catheter, causing the affixed side to bend, thus forming a loop. In some embodiments m which a portion of the ligating element is affixed to the distal end of the catheter, the unaffixed side of the ligating element can be magnetized. In such embodiments, a clinician can use a magnet or magnetic system outside the subject's body to manipulate the ligating element and poll the unaffixed, magnetized side of the ligating element into the catheter, thus causing the ligating element to form a lariat. In some cases m which a portion of the ligating element is magnetized, a device may lack a separate control element.
• Once the ligating element is in position, the control element can be released to close the ligating element. The ligating element can be separated from the elongate element and, in some cases, from all or a portion of the control element. Any suitable means can be used to separate the ligating element from other elements of the device. An inner control element can be left entirely or partially inside the ligating element. An enter control element can be entirely or partially removed from the ligating element.
• In some embodiments, a rigid ligating element can be connected to an elongate element by a pin or other mechanism at its base to, for example, allow a clinician to adjust the angle of the ligating element with respect to the elongate element (e.g., once the ligating element has been advanced beyond the distal end of the catheter). The ability to manipulate the angle of the ligating element can facilitate positioning of the ligating element over the LAA.
• In some embodiments, a device can include a ligating element in the form of a ring clip (e.g., manufactured of shape memory wire) whose natural position is closed, and a hollow, donut-shaped control element comprising a soft pliable material (e.g., PTFE, polyethylene, or polypropylene) that is air tight. In some embodiments., the ring clip can be contained within the control element. For example, a ring clip (formed of, e.g., Nitinol) can be contained within a hollow ring, (of, e.g., PTFE). In some cases, the ring clip can encircle the outer circumference of the control element. For example, a ring clip (formed of, e.g., Nitinol) can encircle a hollow ring (of, e.g., PTFE). The device can be deployed by advancing the ligating element (ring clip) and the control element out of the distal end of the catheter, inflating the control element (e.g., with a gas or a liquid) to open the ring clip, positioning the device at the base of the LAA, and deflating the control element to close the ring clip. In such embodiments, the control element can provide an atraumatic covering for the ligating element.
• In some embodiments, a device can have an elongate rigid control element (e.g., a wire) with a ligating element (e.g., a suture) affixed to one end. The control element can extend through the length of the catheter, e.g., with a generally elongate “U” shape in which both ends protrude from the proximal end of the catheter and the bottom of the “U” is positioned at or near the distal end of the catheter A clinician can manipulate the position of the control element using, for example, a positioning element as described herein, or using a magnet in cases where the control element is magnetized. Once the control element is placed around the LAA, the end of the control element that is not attached to the ligating element can be pulled to advance the ligating element through the catheter and around the LAA. When the ligating element is in place around the base of the LAA, it can be fastened in place (e.g., knotted or clipped), and any remaining portion of the ligating element and the control element can be retracted from the subject's body;
• In some cases, the ligating device can include a protective element. For example, the ligating device can include a hollow tubular sheath that can surround a portion of the control element at the distal end of the catheter, and can be placed around the LAA (or other anatomical structure) along with the control element. Such a sheath can protect the tissue from, frictional damage as the control element is pulled through the catheter and the suture is positioned around the LAA (or other anatomical structure). A protective element also can distribute the force of the suture over a greater area of the LAA.
• In some embodiments, a ligating device of the present invention can include a control dement having two rigid elongate portions (e.g., two lengths of wire extending through the catheter) with a flexible ligating element attached to the ends of the control element closest to the distal end of the catheter. By manipulating the elongate portions of the control element with respect to one another, a clinician can cause the flexible ligating element to form a lariat that can be placed around the LAA (or other anatomical structure). A fastening means (e.g., a clip) can be passed through the catheter (e.g., along one or both portions of the control element) to retain the ligating element around the base of the LAA. Once the lariat is in place, a clinician can cut any excess portion of the ligating element, and remove the device from the subject's body.
• Ligating devices of the present invention can include one or more additional elements to assist with positioning of the ligating element and/or the LAA (or other anatomical structure). These additional elements can, e.g., be contained within the catheter or within an outer sheath that also contains the catheter. Positioning elements can be deflecting and/or steerable to, for example, facilitate their positioning within a device.
• Appendage positioning elements can include, for example, suction catheters, forceps, and cryogenic-tipped catheters, which can be used to lift and hold the LAA while the lariat is put into position at its base. See, e.g., U.S. Patent Application Publication Nos. 2005/0154404 and 2004/0030335, as well as U.S. Pat. No. 6,488,689. An appendage control device can be, for example, a suction device, a grasper device, or a cryogenic device. A suction device can lift and/or bold the LAA by applying a gentle vacuum to the surface of the LAA, while a grasping device can physically hold the LAA. A cryogenic appendage control device can be, for example, a probe with a cooled tip that can attach to the LAA like a tongue to a cold flag pole, and that can be warned to permit removal front the surface of the LAA with minimal trauma to the tissue.
• In addition or alternatively, a positioning element can be used to help position and place the ligating element. A positioning element can be rigid or at least substantially rigid, as in the case of a rod comprising wire, plastic, or any other suitable material. Alternatively, a positioning element can be flexible, as in the ease of a suture having a loop through the lariat. In some cases, a positioning element can be releasably attached to the lariat via any suitable means (e.g., threads, a pin, or a magnet), or can include a hook at one end for grasping the lariat. The positioning element can be used to push, pail, or otherwise maneuver the lariat into position, and can remove the positioning element from the lariat once the device is positioned around the LAA. In some embodiments, a first lariat can be positioned around the LAA, and then can foe used as a positioning and/or control element to facilitate placement of a second lariat around the base of the LAA.
• The ligating devices provided herein can have any suitable length and width (e.g., diameter). For example, a device can have a length between about 12 inches and about 72 inches (e.g., between about 24 inches and 60 inches, between about 30 inches and about 54 inches, or between about 36 inches and about 48 inches), such that its distal end can be placed within the pericardial space proximate the LAA and its proximal end can be positioned outside a subject's body. Further, a device can have any suitable diameter. For example, a device can have an overall diameter (e.g., diameter of the outer sheath, or diameter of the catheter if there is no outer Sheath) suitable for passage through the circulatory system and into the coronary sinus, for passage between adjacent ribs, or for sub-xiphoid passage. Thus, a device can have a diameter between about 0.05 cm and about 1.5 cm, between about 0.1 cm and about 1.0 cm, between about 0.15 cm and about 0.5 cm, between about 0.2 cm and about 0.4 cm, or about 0.2 cm, about 0.3 cm, or about 0.4 cm. The device may be flexible to permit navigation through curved and finite planes (such as the pericardial space) leading to the anatomical structure (such as the LAA),
• The ligating devices provided herein can be used in any suitable type of minimally invasive approach. In some embodiments, a ligating device can be used in an intercostal approach. For example, a mini-thoracotomy procedure can be used in which the distal end of a device can be inserted through a small incision into the chest cavity and advanced between the ribs to the pericardium. In some embodiments, a sub-xiphoid approach can be used, in which the distal end of a device is inserted into the chest cavity through a small incision and advanced between the xiphoid process and adjacent intercostal cartilage until if reaches the pericardium. In some cases, a suprasternal approach can be used, in which the-distal end of a device is inserted into the chest cavity through a small incision above the sternum, and advanced interiorly toward the pericardium. For intracostal, sub-xiphoid, and suprasternal approaches, the distal end of a device can be advanced into the pericardial space through the pericardium (i.e., from the exterior of the pericardium), and positioned at or near the LAA.
• In some embodiments, controlled exit from the coronary sinus (CS) can be used. CS exit can be advantageous in that the angle of approach can facilitate encircling the LAA at its base. In this approach, a device (e.g., a tapered, flexible sheath or catheter) can be passed into the coronary sinus via, for example, a femoral vein, a jugular vein, or a subclavian vein. The sheath can have a hollow needle and/or a wire contained therein when it is passed into the CS, or a needle and/or wire can be passed through, the sheath after it reaches the CS. The tip of the device can be positioned within the CS, and the distal end of the needle or wire can be advanced through the wall of the CS and into the pericardial space proximate the LAA. In some embodiments, the distal end of the sheath or needle can be curved or angled, such that a wire contained therein is directed to exit the needle toward the CS wall rather than into the lumen of the CS. A similar approach discussed herein could potentially be used to facilitate a controlled exit from the right atrial appendage.
• A device can include any suitable mechanism to facilitating piercing of the CS wall. For example, the needle can contain a wire that can be “cocked” with a spring mechanism. A clinician can actuate the spring mechanism, and the resulting forward pressure applied on the wire element can cause the needle or the wire within the needle to pierce the CS wall. In some embodiments, the wire can be configured such that once it enters the pericardial space, it can curve and/or kink to prevent further advance of the needle beyond the pericardial space. For example, a wire can be configured to coil alter piercing the CS wall, thus reducing the likelihood of or preventing the end of the wire from puncturing the pericardial sac or damaging the outer surface of the heart. In some cases, a device can be configured such that the length of wire deployed from the device is limited. For example, the length of wire that exits the catheter or needle is limited to between about 0.5 mm and about 3 mm (e.g., about 0.5 mm, about 1 mm, about 1.5 mm, about 2 mm, about 2.5 mm, or about 3 mm).
• In some embodiments, a wire can have a EP electrode at its tip. Thus, RF energy can be used to create an. opening in the CS wall for passage of the needle or catheter The RF energy can be turned off once the CS wall is pierced, to prevent puncture of the pericardial sac. The sheath and/or the hollow needle can have an angled or curved end, which can facilitate placement advancement of the wire toward and through the CS wall.
• Once the CS wall is pierced, the device (e.g., the sheath, the needle, or the wire) can be advanced into the pericardial space. The wire and, in some embodiments, the needle, can be removed from the sheath, and a ligating device as described herein can be passed through the sheath and advanced into the pericardial space. In some embodiments, a RF ablation electrode can be passed along or over the wire and into the pericardial space, and can be used for pericardial mapping and/or ablation. A sheath and/or a hollow needle having an angled or curved end can facilitate placement of a ligating device or a RF electrode within the pericardial space.
• In some embodiments, a device can include a balloon that can be deployed within the CS to prevent or reduce blood leakage into the pericardial space, and/or to stabilize the device. The balloon can be connected to a fluid conduit that extends through the sheath, and through which a fluid such as air, oxygen, water, or saline can be passed into the balloon. The balloon can be inflated when the device is positioned within the CS, and can be deflated prior to removal of the device from the CS.
• After the LAA is ligated, the ligating device can be removed. In some embodiments, the opening in the wall of the CS can be closed. Any suitable technique can be used, including RF ablation or physical closure using one or more hooks and/or needles. For example, a RF-tipped wire can be passed through the sheath or needle to the CS wall, and RF energy can be used to weld the opening. In some cases, tissue at the opening in the CS wall can be pulled into the distal end of the sheath, or needle (e.g., using suction or a mechanical grasper), where it can be sutured closed or welded together using RF energy. In some embodiments, a balloon can be passed through the sheath to prevent or reduce blood flow from the CS into the pericardial space.
• To use the ligating devices provided herein, in general, a clinician can position the distal end of a device provided herein, within, the pericardial space proximate the LAA. The device, or a portion thereof (e.g., the catheter) can be steerable using, for example, conventional steerable sheath technology. A clinician can advance the ligating element and control element out o f the distal end of the catheter.
• A clinician can use the control element and/or a separate positioning rod or suture to position the ligating element around the LAA. In some embodiments, a separate appendage control device as described herein can be used to lift and/or hold the LAA to facilitate suitable placement of the ligating element. Positioning elements can be deflecting, and/or steerable. Whether or not a separate control or positioning element is used, once the ligating element is in position, the control element can be removed if desired, and die ligating element can be tightened (around, e.g., the base of the LAA). It is noted that, while in most embodiments the control, element and the ligating element are passed through the same device (e.g., the same catheter), control, ligating. and positioning elements can be passed to the LAA through separate devices, such that two or more pericardial access points can be used.
• Turning now to the figures, exemplary embodiments of ligating devices in which the ligating element is in the form of a pliable hollow material and the control element comprises a shape-memory wire are depicted inFIGS. 1-10.Device10 can includecatheter20 with a proximal end (not shown) anddistal end25.Catheter20 can contain ligatingelement30 andcontrol element40, whereincontrol element40 is disposed within the lumen of ligatingelement30. In these embodiments, ligatingelement30 can be, for example, a hollow suture, and controlelement40 can be a wire.Catheter20 may be placed directly into the pericardial space, or it may enter through a separate sheath already positioned with its distal end in the pericardial space. In addition, the catheter and/or sheath may be steerable. Although the devices are described herein as exiting from the distal ends of the catheters, it should be understood that the exit port through which the devices exit the catheters may be located in the catheter sidewall proximate the distal ends of the catheters or at the very tip of the catheters (as depicted in, e.g.,FIG. 2).
• Control element40 can be manufactured of shape-memory material, and can be configured such that, for the portion ofcontrol element40 atdistal end25, the control element has an “original” or “preferred” shape approximating a loop (e.g., a circle or an oval). Thus, whencontrol element40 is contained withincatheter20 as shown inFIG. 1 (in a closed configuration), it can be compressed into a U-shape that Is folded back on itself, but when it is pushed out ofdistal end25, it can expand to formlariat43 as shown inFIG. 2. As such, the loop configuration ofcontrol element40forces ligating element30 to adopt a lariat (open) configuration suitable for positioning around, e.g., the LAA. Additionally, preferentially pulling (proximal retraction) on one or the other proximal end of the control elements may modify the shape of the distal loop/lariat to assist with conformation to anatomic variations.
• In some embodiments,control element40 can be configured such that upon advancement pastdistal end25 of thecatheter20, thecontrol element40 assumes a shape in which lariat43 is oriented at an angle with respect to theelongate portion46 of control,element40. For example, as shown inFIG. 3,lariat43 can be at approximately a 90 degree angle with respect to elongateportion46 ofcontrol element40.Lariat43 can be at any suitable angle with respect to elongate portion46 (e.g., an angle of about 20, 30, 40, 45, 50, 60, 70, 80, 85, 90, 95, 100, 110, 120, 130, 135, 140, 145, or 150 degrees).
• In addition or alternatively, the shape assumed bycontrol element40 can include one or more angled portions, such asangled portion48 as shown inFIGS. 4A and 4B.Angled portion48 can further facilitate placement of ligatingelement30 around the LAA, and also can facilitate access by an appendage control device (see, e.g.,FIG. 6).
• In some embodiments,device10 can further includepositioning element50, as depicted inFIG. 5.Device10 also can includeouter sheath60, wherecatheter20 andpositioning element50 are contained withinouter sheath60. In some embodiments, positioningelement50 can be contained withincatheter20. Positioningelement50 can includeloop54 andelongate portion56.Loop54 can encircle any portion of ligatingelement30. For example,loop54 can encircle ligatingelement30 at a position proximate the base oflariat43, as shown inFIG. 5A, or can encircle ligatingelement30 at or near the distal end oflariat43,Elongate portion56 can extend through the length ofouter sheath60 orcatheter20, such that, positioningelement50 can be manipulated outside the body. In use,positioning element50 can be used to manipulate the position of ligating element30 (e.g., to deflectlariat43, as shown inFIG. 5B), and thus can facilitate placement of ligatingelement30 around the base of the LAA. This element may also potentially be used to loosen a knot after placement and/or facilitate advancement of a cutter through the sheath, to remove a loop if, e.g., its position is deemed not favorable.
• Alternatively or in addition, ligatingdevice10 can include appendage control means70. Appendage control means70 can be contained within the lumen ofcatheter20, as shown inFIG. 6, or can be contained within an outer sheath. Appendage control means70 can extend through the length ofcatheter20 or through an outer sheath, and can be in the form of, for example, a suction device, a grasper device, cryogenic device, etc. In use,distal end75 of appendage control means70 can be advanced out ofcatheter20 and, in some embodiments, throughlariat43, to contact the LAA and hold or lift it Into a position suitable for placement of ligatingelement30 over the LAA. Once ligatingelement30 is placed around the LAA, the LAA can be released from appendage control means70 by removal of suction if a suction device, by appropriate actuation if a grasper device, or by warming if a cryogenic device. Appendage control means70 then can be retracted intodevice10, or can be advanced to re-grasp the LAA at, for example, a more proximal site, permitting further advancement ofcontrol element40 toward the base of the LAA.
• Once ligatingelement30 is positioned around the base of the LAA,control element40 can be removed if desired. For example, a clinician can pull on one end ofcontrol element40 in the direction of the arrow shown, inFIG. 7 to remove it entirely or partially from ligatingelement30. In such an embodiment, thecontrol element40 is preferably slidably fitted within the ligatingelement30, i.e., thecontrol element40 can be pulled oat of the ligatingelement30 while the ligatingelement30 remains in its selected position (e.g., around an LAA, etc.). Alternatively,control element40 can be left within ligatingelement30.
• Ligatingelement30 can be tightened and held in position around the LAA using any suitable retention means including, without limitation, a knot or a clip. For example,knot80 can be tied in ligatingelement30 at a position outside the body, and can be advanced along ligatingelement30 throughcatheter20 using any suitable method or device, including those known, in the art (such as, e.g., a knot pusher (net shown)).FIG. 8 depictsknot80 as it approachesdistal end25 ofcatheter20,. whileFIG. 9 depictsknot80 as it can appear in position at a tightened loop around the LAA. In some embodiments, a clip can be advanced through device10 (e.g., throughcatheter20 or through outer sheath60) and positioned around ligatingelement30.
• In some embodiments, ligatingdevice10 can include a means for repositioning ligatingelement30 after it has been tightened around the LAA. As shown inFIG. 10, for example, positioningelement50 can be used to reposition ligatingelement30. By pullingpositioning element50 in the direction of the arrow shown inFIG. 10, a clinician can pull knot90 towardcatheter20, such that ligatingelement30 can be loosened and/or repositioned.
• In some embodiments, the control element threaded through the lumen of a hollow ligating element may include portions of different, thickness. Referring toFIG. 10A, the catheter20ahas a distal end25afrom which the lariat, or loop43aformed in the ligating element30aextends. Acontrol element40aextends through a lumen in the ligating element30a.One feature of the ligating device depicted inFIG. 10A is that aknot80ais formed in the ligating element30awhile thecontrol element40ais located in the portion of the ligating element30acontaining theknot80a.
• Thecontrol element40acan include two or more different portions. For example, thecontrol element40acat) include a distal portion located between the distal end44aand the transition45a,and a proximal portion located between the transition45aand the proximal end (not shown) of thecontrol element40a.The proximal end of thecontrol element40a(not shown) may preferably extend outside of the proximal end (also not shown) of the catheter20a.
• An additional feature of thecontrol element40adepicted inFIG. 10A is that the thickness of the distal portion of thecontrol element40a(i.e., the portion between the distal end44aand the transition45a) is less than the thickness of the proximal portion of thecontrol element40a(i.e., the portion of thecontrol element40afrom the transition45ato the proximal end of thecontrol element40a). The thinner distal portion of thecontrol element40amay be thin enough such that theknot80acan be formed in and advanced along the ligatingelement30 such that theknot80ais located proximate the distal end25aof she catheter20abefore the lariat43ais advanced out of the catheter20a.In addition, the distal portion of thecontrol element40amay be thin enough such that, after deployment of the ligating element30a,thecontrol element40acan be removed from the ligating element30aby, e.g., polling on the proximal end of thecontrol element40asuch, that the distal portion of thecontrol element40ais removed from the knot and the lariat or loop43a.
• Although the thickness differential in she controlelement40ais depicted as occurring within a relatively small distance in the embodiment ofFIG. 10A, the thickness of thecontrol element40amay change gradually over a significant distance, provided that the thickness of thecontrol element40apassing through theknot80adoes not prohibit removal of thecontrol element40a(if its removal is desired).
• Another exemplary embodiment of a ligating device10bis depleted inFIG 10B. The depicted ligating device includes a primary control element40band a secondary control element48b,both of which are threaded through portions of the ligating element30b.As in previously described embodiments, the catheter20bhas a distal end25bfrom which the lariat orloop43bformed in the ligating element30bextends.
• The ligating element30bincludes a first portion32bextending along the right side of the catheter20b(as seen inFIG. 10B) towards theloop43b.The ligating element30balso includes a second portion33bextending along the left side of the catheter20h(as seen inFIG. 10B) towards theloop43b.A knot80bis formed in the ligating element30b.More particularly, in the depicted embodiment, the knot80bis formed in the portion32bof the ligating element30b,and the portion33bof the ligating element30bextends through the knot80b.As a result, the knot80bmay be potentially referred to as a slip knot that can be advanced along the portion33bwhile the control element40bremains in position within the ligating element30b.
• The primary control element40bpreferably forms aloop43bas depicted, with the ligating element30bconforming to the shape of theloop43bformed by the control element40b.The primary control element40bhas a distal end44bthat may preferably be located distal of the knot80b.In other words, the primary control element40bmay preferably not extend into the knot80bas formed in portion32bof the ligating element30b.in another characterization, the primary control element40bmay be described as having a distal end44bthat is not located within or proximally of the knot80b(as delivered for use in a subject).
• Although the portion of the primary control element40bwithin the left-hand portion33bof the ligating element30hdoes extend through the knot80b,that port ion33bof the ligating element80bis relatively straight and does not contain the bends associated with the knot80b.As a result, the control element40bmay not need to be more rigid than, for example, the portion of thecontrol element40athat extends through theknot80ain ligatingdevice10aas described in connection withFIG. 10A. That increased rigidity may assist in formingloop43bin the ligating element30b.
• In some embodiments, it may be preferred that the distal end44bof the primary control element40bbe located within theloop43b(and not extend into the portion32bof the ligating element30bthat leads to theloop43b—see, for example,FIG. 7). Alternatively, the primary control element40bcan be withdrawn (retracted proximally) as the knot80bis advanced distally such that the distal end44bof the control element40bremains outside of the knot80bas formed in portion32bof the ligating element30b.
• The ligating device10bdepicted inFIG. 10B includes an optional secondary control element48bthat extends through the portion32bof the ligating element30b.It may be preferred that the secondary control element48bhave a distal end49bthat is located proximally of the knot80bsuch that the secondary control element48bdoes not extend through the knot80b.In some embodiments, the secondary control element48bmay be advanced distally as the knot80bis advanced distally to provide support and rigidity to the portion32bof the ligating element30bas the knot is advanced.
• Once the clinician has determined that ligatingelement30 is in a suitable position and does not need to be moved, a suitable device (e.g., a scissors, scalpel, clipper, or any other useful device) can be advanced through device10 (e.g., along positioning element50) to cut ligatingelement30 andcontrol element40, if applicable, proximate the retention means (e.g., knot90). Ligatingelement30 can be left in position, around the base of the LAA, and the remainder ofdevice10 can be removed from the subject's body. Alternatively, if the position of ligatingelement30 around the LAA is deemed unsuitable, the cutting device can be used to cut throughlariat43, permitting complete removal of ligatingelement30.
• Exemplary embodiments of the ligating devices in which the ligating element is formed of rigid material and the control element is formed of pliable material are depicted inFIGS. 11-15.Ligating device110 can includecatheter120 with a proximal end (not shown) anddistal end125.Catheter120 can contain ligatingelement130 connected to elongateelement135, which can extend through the length ofcatheter120.Catheter120 also can containcontrol element140, which can be disposed within all or a portion of ligatingelement130.
• In this embodiment, ligatingelement130 can be formed of shape memory material (e.g., Nitinol), andcontrol element140 can be a suture or a pliable wire. Ligatingelement130 can be configured to have an original shape that is closed, (e.g., a closed or flattened loop) as shown inFIGS. 11 and 12, for example. A clinician can advance ligatingelement130 out ofdistal end125, and then can open ligatingelement130 by actuatingcontrol element140.
• For example, with embodiments in which controlelement140 extends throughcatheter120, into and completely throughligating element130, and back throughcatheter120, (as depicted inFIGS. 12 and 13A), both ends ofcontrol element140 can protrude from the proximal end ofcatheter120. By pulling on both ends of control, element140bthe direction of the arrows shown inFIG. 13A, a clinician can actuateligating element130, causing it to open.
• In other embodiments,control element140 can extend throughcatheter120 and intoligating element130, where it can be secured, at or neardistal end143 of ligating element130 (e.g., at point148). In such embodiments, as depleted inFIG. 13B, one end of control element can protrude from the proximal and ofcatheter120. A clinician can. pull on the protruding end ofcontrol element140 to open ligatingelement130. In either case, actuation ofcontrol element140 can causeligating element330 to expand andform lariat143, which can be suitable for positioning around the LAA.
• Ligating device110 can further includepositioning element150 andpivot pin155, shown inFIGS. 14 and 15.Pivot pin155 can be located at the junction of ligatingelement130 andelongate element135, and in some embodiments can be used to connect ligatingelement130 to elongateelement135.Positioning element150 can be contained withincatheter120, as shown inFIGS. 14 and 15, or can be contained within an enter sheath.Positioning element150 can include loop160 and elongate portion165. Loop160 can encircle a portion of ligatingelement130. A clinician can pull on elongate portion165 ofpositioning element150 in the direction indicated by the arrow inFIG. 13. The resulting force of loop160 on ligatingelement130 can causeligating element130 to rotate aboutpivot pin155, so that ligatingelement130 is at an angle with respect to elongateelement135. Ligatingelement130 can be adjusted to any suitable angle with respect to elongate element135 (e.g., an angle of about 20, 30, 40,45, 50, 60, 70, 80, 85, 90, 95, 100, 110, 120, 130, 135, 140, 145, or 350 degrees). Typically,positioning element150 can be used to adjust the angle of ligatingelement130 afterlariat143 is formed by pulling oncontrol element140. In some embodiments, however, the angle of ligatingelement130 can be adjusted before or afterlariat143 is formed.
• Once ligatingelement130 is in place around the LAA,control element140 can be released, allowing ligatingelement130 to assume its original shape and thus tighten or close around the base of the LAA.Control element140 can be removed from ligatingelement130, or can be left within the interior of ligatingelement130. After a clinician is satisfied with the position of ligatingelement130 around the LAA, a suitable cutting or detaching device (e.g., a scissors, scalpel, clipper, or any other useful device) can be advanced throughdevice110 to detach ligating element130 (andcontrol element140, if applicable) fromelongate portion135. Ligatingelement130 can be left in position around the base of the LAA, and the remainder ofdevice110 can be retracted from the subject's body.
• In the exemplary embodiments depicted inFIGS. 16-18, ligatingdevice210 can havecatheter220 with a proximal end (not shown) anddistal end225, with ligatingelement230,elongate element235, and hollow donut-shapedcontrol element240 contained therein.Elongate element235 can extend through the length ofcatheter220, andcontrol element240 can be connected to elongateelement235 and positioned at or neardistal end225. Ligatingelement230 can be contained withincontrol element240, as shown inFIGS. 16-18, or can encircle the outer circumference ofcontrol element240.
• In some embodiments, ligatingelement230 can be a ring clip whose natural position is closed (i.e., in the absence of external forces, the ligatingelement230 is in the closed position as depicted inFIG. 16), ligatingelement230 can be formed of, e.g., Nitinol or any other suitable shape memory material.Control element240 can be formed of soft pliable material (e.g., PTFE, polyethylene, or polypropylene) that is air tight.Control element240 also can provide an atraumatic covering for ligatingelement230 if ligatingelement230 is contained withincontrol element240, or can serve as a tissue protector if ligatingelement230 ex tends around the circumference ofcontrol element240.
• In some embodiments, ligatingdevice210 includes a conduit in fluid communication withcontrol element240. For example,elongate element235 can beconduit250 in. fluid communication with the interior ofcontrol element240. Alternatively, ligatingdevice210 can include a separate fluid conduit.Conduit250 can have a length such that it can extend through catheter220 (or through an outerSheath containing catheter220, if applicable) between the proximal end. anddistal end225. A clinician can pass fluid intoconduit250 from outside the subject's body. In these embodiments, ligatingdevice210 can be deployed by inflatingcontrol element240 with, for example, a gas (e.g., air, oxygen, or nitrogen) or a liquid (e.g., saline or water) passed throughconduit250. Inflation ofcontrol element240 can causeligating element230 to open, forming lariat243.
• In some embodiments, ligatingdevice210 can further includepositioning element260, shown inFIG. 18.Positioning element260 can have a length such that it can extend throughcatheter220 between the proximal end anddistal end225. In some embodiments, positioning element280 can be reversibly attached to controlelement240.
• A clinician can then position ligatingdevice210 at the base of the LAA and deflatecontrol element240 to close ligatingelement230. For example, a clinician can removeconduit250front control element240. The removal ofconduit250, in combination with inward pressure exerted by ligatingclement230, can causecontrol element240 to deflate. Oncedevice210 is positioned around the base of the LAA and deflated, a clinician can detachfluid conduit250 andpositioning element260, if applicable from ligatingelement230 andcontrol element240. The remainder of ligatingdevice210 can be removed from the subject's body, while ligatingelement230 andcontrol element240 remain.
• In the exemplary embodiments depicted inFIGS. 19 and 20, ligatingdevice310 can includecatheter320 with a proximal end (not shown) anddistal end325. Ligatingelement330 andcontrol element340 can be positioned withincatheter320.Control element340 can include firstelongate portion341 and secondelongate portion342. Ligatingelement330 can be attached to the distal ends ofelongate portions341 and342. A clinician can manipulate first and secondelongate portions341 and342 with respect to one another, and can causeligating element330 to formlariat343, as shown InFIG. 20.Lariat343 can be positioned around the base of the LAA, and a clip or other suitable fastening means can be passed throughcatheter320 to retain ligatingelement330 in position. A cutting device can be used to severlariat343 from the remainder of ligatingelement330, and the device can be removed from the subject's body.
• In the exemplary embodiments shown inFIGS. 21 and 22, ligatingdevice410 includes acatheter420 with a proximal end (not shown) and distal end423, whereincontrol element440 is positioned within the lumen ofcatheter420.Control element440 can be formed using a substantially rigid material (e.g., wire).Control element440 can have a generally elongate “U” shape, such, that it can extend through the length ofcatheter420, with both ends protruding from the proximal end ofcatheter420 and the bottom of the “U” positioned at or neardistal end425 ofcatheter420. A lariat or loop can form when the distal end ofcontrol element440 is advanced out ofdistal end425, as shown inFIG. 21.
• Ligatingelement430 can be attached to one end ofcontrol element440, and can be, for example, a suture.Device410 also can include aguard450, which can be a hollow, flexible suture or sheath that covers the portion ofcontrol element440 that is to be placed around the LAA (or other anatomical structure). Although theguard450 is depicted as terminating relatively close to the loop, theguard450 could alternatively extend towards the proximal end of the catheter420 (even as far as extending out of the proximal end of the catheter420).
• Device410 also can include a positioning element (not shown) to facilitate placement of control element440 (around, e.g., the base of the LAA). Whencontrol element440 is suitably positioned around the LAA, a clinician can pull on the free end ofcontrol element440 in the direction indicated by the arrow inFIG. 22, advancingligating element430 towarddistal end425 ofcatheter420 and throughguard450, as shown inFIG. 22, such thatligating element430 fakes the place of thecontrol element440 and is positioned around the LAA. Any suitable mechanism (e.g., a clip or a knot and described herein) then can be used to retain ligatingelement430 in position. Excess portions of ligating element430 (e.g., portions that are not positioned around the LAA) can be cut, and the device can be removed from the subject's body.
• The devices depicted inFIGS. 23 through 26 are examples of devices that can be used for placement of a ligating device via the CS.Device510 can includesheath520,hollow needle530, andwire540, which can each have a proximal end (not shown) anddistal ends525,535,545, respectively. In some embodiments,device510 does not includeneedle530. As shown inFIGS. 23 and 24,distal end525 ofsheath520 can be tapered. In some embodiments,distal end525 is not tapered.
• Device510 can be advanced intoCS550, andneedle530 and/orwire540 can pierce the wall ofCS550. Any suitable methods can be used to pierce the wall ofCS550 and to preventwire540 orneedle530 from puncturing the pericardial sac. As depicted inFIG. 24, for example,distal end545 ofwire540 can be configured to coil after being deployed out ofdevice510 and through the wall ofCS550. As shown inFIG. 25,distal end535 ofneedle530 can be curved, such that whendistal end545 ofwire540 exits needle530, it is directed toward the wall ofCS550.
• In some embodiments, means can be used to reduce or prevent the flow of blood from out of the CS and into the pericardial space. As shown inFIG. 26, for example,balloon560 can be passed throughdevice510, and can be inflated within the lumen of the CS.Balloon560 can be connected tofluid conduit565, through which a fluid such as air, oxygen, saline, or water, for example, can be passed to inflate and deflateballoon560.Balloon560 can be passed throughsheath520 in an uninflated state, and can be inflated once it is within the lumen of the CS. When inflated,balloon560 can reduce the flow of blood, indicated by the arrow inFIG. 26, into the pericardial space through the opening created bywire540.
• In some embodiments,device510 also can include means for closing an. opening in the CS wall after completion of a procedure (e.g., ligation of the LAA, atrial ablation, or pericardial mapping) within the pericardial space. In some cases, a wire having a RF tip at its distal end can be passed through the sheath or the needle of a device. Once the tip of the wire reaches the opening in the CS wall, RF energy can be used to weld the opening. For example, as depicted inFIG. 27,device510 can containwire570 havingRF tip575. As shown,wire570 can be advanced throughneedle530 untilRF tip575 reaches opening555 in the wall ofCS550, and RF energy can be applied to weld tissue adjacent toopening555.
• In some cases, a suction device having needles or RF tipped wires disposed therein can be used to close an opening in the CS wall As shown inFIG. 28, for example,device510 can havehollow suction catheter580 extending therethrough.Suction catheter580 can have a proximal end (not shown),distal end582 andside opening585, and can contain (e.g., within its lumen or within longitudinal channels within it's walls) needles590 and592, which can havedistal ends595 and597, respectively.Suction catheter580 can be advanced throughsheath520 untilside opening585 is positioned adjacent to opening555 In the wall ofCS550. Suction can be used to pull tissue around opening555 into side opening585 ofcatheter580, and needles590 and592 can be manipulated to physically suture tissue adjacent toopening555. Once opening555 is suitably closed,device510 can be withdrawn from the subject's body.
• It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scone of the following claims.

Claims (21)

1-30. (canceled)

31. A ligating device comprising:

a catheter comprising a proximal end and a distal end;

a ligating element located within the catheter, wherein the ligating element comprises a lumen and a first end and a second end, wherein the first end and the second protrude from the proximal end of the catheter;

a control element located within the lumen of the ligating element, the control element comprising a first end that protrudes from the ligating element and a second end located in the lumen of the ligating element, wherein a distal portion of the control element forms an open loop upon exit from the distal end of the catheter, wherein the open loop is compressed when the distal portion of the control element is located within the catheter, wherein the control element forces the ligating element to adopt a lariat configuration when the distal portion of the control element forming the open loop extends out of the distal end of the catheter; and

a knot formed in a portion of the ligating element, wherein the knot is located in the catheter proximal of the lariat configuration of the ligating element when the distal portion of the control element forming the open loop extends out of the distal end of the catheter, and wherein the knot is located in the catheter between the first end of control element and the distal end of the catheter when the distal portion of the control element forming the open loop extends out of the distal end of the catheter, and wherein the knot is located in the catheter between the second end of control element and the distal end of the catheter when the distal portion of the control element forming the open loop extends out of the distal end of the catheter.

32. A ligating device according toclaim 31, wherein the control element is removable, such that the control element can be pulled out of the lumen of the ligating element.

33. A ligating device according toclaim 31, wherein the control element extends through the portion of the ligating element that comprises the knot.

34. A ligating device according toclaim 31, wherein the control element comprises a distal portion and a proximal portion, and further wherein the distal portion is thinner than the proximal portion.

35. A ligating device according toclaim 31, wherein the ligating element comprises a hollow suture and the control element comprises shape memory material.

36. A ligating device according toclaim 31, further comprising a grasping element configured to advance to a position distal of the distal end of the catheter.

37. A ligating device according toclaim 36, wherein the grasping element is configured to extend through the lariat configuration of the ligating element when the distal portion of the control element forming the open loop extends out of the distal end of the catheter.

38. A ligating device according toclaim 31, wherein the catheter is located within a sheath and further wherein a grasping element is configured to advance through the sheath to a position distal of the distal end of the catheter, wherein the grasping element is configured to grasp a left atrial appendage for placement of the ligating element over the left atrial appendage when the ligating element forms a lariat configuration when the distal portion of the control element forming the open loop extends out of the distal end of the catheter.

39. A ligating device comprising:

a catheter comprising a proximal end and a distal end;

a ligating element located within the catheter, wherein the ligating element comprises a lumen and a first end and a second end, wherein the first end and the second protrude from the proximal end of the catheter;

a control element located within the lumen of the ligating element, the control element comprising a first end that protrudes from the ligating element and a second end located in the lumen of the ligating element, wherein a distal portion of the control element forms an open loop upon exit from the distal end of the catheter, wherein the open loop is compressed when the distal portion of the control element is located within the catheter, wherein the control element forces the ligating element to adopt a lariat configuration when the distal portion of the control element forming the open loop extends out of the distal end of the catheter; and

retention means for tightening and retaining the ligating element in position around a left atrial appendage, wherein the retention means is located in the catheter proximal of the lariat configuration of the ligating element when the distal portion of the control element forming the open loop extends out of the distal end of the catheter, and wherein the retention means is located in the catheter between the first end of control element and the distal end of the catheter when the distal portion of the control element forming the open loop extends out of the distal end of the catheter, and wherein the retention means is located in the catheter between the second end of control element and the distal end of the catheter when the distal portion of the control element forming the open loop extends out of the distal end of the catheter.

40. A ligating device according toclaim 39, wherein the retention means comprises a knot formed in the ligating element.

41. A ligating device according toclaim 40, wherein the control element extends through the portion of the ligating element that comprises the knot.

42. A ligating device according toclaim 39, wherein the retention means comprises a clip.

43. A ligating device according toclaim 39, wherein the control element is removable, such that the control element can be pulled out of the lumen of the ligating element.

44. A ligating device according toclaim 39, wherein the control element comprises a distal portion and a proximal portion, and further wherein the distal portion is thinner than the proximal portion.

45. A ligating device according toclaim 39, wherein the ligating element comprises a hollow suture and the control element comprises shape memory material.

46. A ligating device according toclaim 39, further comprising a grasping element configured to advance to a position distal of the distal end of the catheter.

47. A ligating device according toclaim 46, wherein the grasping element is configured to extend through the lariat configuration of the ligating element when the distal portion of the control element forming the open loop extends out of the distal end of the catheter.

48. A ligating device according toclaim 46, wherein the grasping element is configured to advance through the catheter such that the grasping element extends out of the distal end of the catheter.

49. A ligating device according toclaim 39, wherein the catheter is located within a sheath and further wherein a grasping element is configured to advance through the sheath to a position distal of the distal end of the catheter, wherein the grasping element is configured to grasp a left atrial appendage for placement of the ligating element over the left atrial appendage when the ligating element forms a lariat configuration when the distal portion of the control element forming the open loop extends out of the distal end of the catheter.

50. A ligating device according toclaim 38, wherein the grasping element is configured to extend through the lariat configuration of the ligating element when the distal portion of the control element forming the open loop extends out of the distal end of the catheter.

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