Abstract
Methods for closing a left atrial appendage rely on introducing a closure tool from a location beneath the rib cage, over an epicardial surface, and to the exterior of the left atrial appendage. The closure device may then be used to close the left atrial appendage, preferably at its base, by any one of a variety of techniques. One specific technique uses graspers and a closing loop. Methods may include advancing a closure tool adjacent to the left atrial appendage using a sub-xiphoid approach and closing the left atrial appendage using the closure tool. Methods may also include advancing a loop adjacent to the left atrial appendage using a sub-xiphoid approach and closing the left atrial appendage using the loop.
Claims
1. A method for closing a left atrial appendage of a patient's heart, said method comprising: advancing a closure tool adjacent to the left atrial appendage using a sub-xiphoid approach; and closing the left atrial appendage using the closure tool.
2. The method of claim 1, wherein closing comprises looping, suturing, stapling, clipping, riveting, clamping, or fusing the left atrial appendage at a neck region thereof.
3. The method of claim 2, wherein closing further comprises engaging the left atrial appendage prior to closing the neck region thereof.
4. The method of claim 1, wherein the method is performed while the patient's heart is beating.
5. The method of claim 4, wherein the method is performed while both lungs of the patient remain inflated.
6. The method of claim 5, wherein the method is performed while the patient is under a local anesthetic.
7. The method of claim 1, further comprising separating the parietal pericardium from the visceral pericardium near the left atrial appendage prior to closing the left atrial appendage to create a space over the left atrial appendage.
8. The method of claim 7, further comprising viewing the left atrial appendage through the space.
9. The method of claim 1, wherein advancing further comprises advancing a distal end of the closure tool through a sheath, into the pericardial space, and over an epicardial surface.
10. The method of claim 1, wherein the closure tool comprises a shaft and a closure loop, and wherein closing the left atrial appendage comprises advancing the closure loop over the left atrial appendage and cinching the loop.
11. The method of claim 1, wherein the closure tool comprises a shaft and a clip, and wherein closing the left atrial appendage comprises advancing the clip over a distal end of the left atrial appendage and closing the clip.
12. A method for closing a left atrial appendage of a patient's heart, said method comprising: advancing a loop adjacent to the left atrial appendage using a sub-xiphoid approach; and closing the left atrial appendage using the loop.
13. The method of claim 12, wherein closing comprises suturing the left atrial appendage at a neck region thereof.
14. The method of claim 13, wherein closing further comprises engaging the left atrial appendage prior to closing the neck region thereof.
15. The method of claim 12, wherein the method is performed while the patient's heart is beating.
16. The method of claim 15, wherein the method is performed while both lungs of the patient remain inflated.
17. The method of claim 16, wherein the method is performed while the patient is under a local anesthetic.
18. The method of claim 12, further comprising separating the parietal pericardium from the visceral pericardium near the left atrial appendage prior to closing the left atrial appendage to create a space over the left atrial appendage.
19. The method of claim 18, further comprising viewing the left atrial appendage through the space.
20. The method of claim 12, wherein advancing further comprises advancing the loop through a sheath, into the pericardial space, and over an epicardial surface.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is an anterior view of a heart illustrating the position of the left atrial appendage relative to the remaining structures of the heart.
(2) FIG. 2 shows the position of the heart in an associated chest cavity and illustrates a preferred percutaneous access site for performing the methods of the present invention.
(3) FIGS. 3 and 3A are perspective views of an exemplary closure tool useful for performing the methods of the present invention.
(4) FIGS. 4A-4C are orthogonal views of the closure device of FIG. 3.
(5) FIG. 5 illustrates an access sheath placed percutaneously into a pericardial space using a sub-xiphoid approach beneath the rib cage as is preferred in the methods of the present invention.
(6) FIGS. 6A-6G illustrate use of the exemplary tool of FIG. 3 in performing the closure of a left atrial appendage according to the methods of the present invention.
(7) FIGS. 6H-6J illustrate a modified closure device for introduction of a balloon expander.
(8) FIGS. 6K-6N illustrate an alternative protocol for use of the exemplary tool of FIG. 3 in performing the closure of a left atrial appendage according to the methods of the present invention.
(9) FIGS. 6O and 6P illustrate alternative clip placement patterns for closing the left atrial appendage according to the methods of the present invention.
(10) FIG. 7A-7C illustrate an exemplary clip which may be used in performing the closure methods of the present invention.
(11) FIG. 8 illustrates a clip insertion tool useful for placing the clip of FIGS. 7A-7C according to the methods of the present invention.
(12) FIGS. 9A-9C are cross-sectional views of the insertion tool of FIG. 8 used in placing the clip of FIG. 7A-7C over a left atrial appendage according to the methods of the present invention.
(13) FIG. 10 illustrates an exemplary kit including a closure device and optional components acconding to the present invention.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
(14) FIG. 1 is an anterior view of a heart illustrating the right ventricle RV, the left ventricle LV, and the left atrial appendage LAA. The methods and apparatus of the present invention are intended to place a closure structure over or otherwise close of the base region BR of the left atrial appendage. By closing off the base region BR, the exchange of materials between the left atrial appendage LAA and the left atrium LA will be stopped. Thus, the release of emboli from the left atrial appendage into the left atrium will be stopped.
(15) Referring now to FIG. 2, the heart is located within the pericardial space PS located beneath the patient's rib cage RC. The sternum S is located in the center of the rib cage RC and terminates at its lower end in the xiphoid X. On either side of the xiphoid are the costal cartilage CC, and the percutaneous access points for performing the procedures of the present invention will be located beneath the rib cage RC, and preferably between the xiphoid X and an adjacent costal cartilage CC, preferably at the access location AL shown by a broken line.
(16) An exemplary tool 10 for performing the methods of the present invention is illustrated in FIGS. 3, 3A, and 4A-4C. The tool comprises a shaft 12 having a distal end 14 and a proximal end 16. A handle 18 is preferably attached to the proximal end of the shaft, and the shaft will have a curved profile in its axial direction (as best seen in FIG. 4B) and a crescent-shaped cross-section, as best seen in FIG. 4C. The preferred dimensions of the shaft are set forth above.
(17) In the illustrated embodiment, the shaft has three lumens 20, 22, and 24. A first lumen 20 is used for introducing a closure tool (which may be any of the closure tools described above), while the second and third lumens (22 and 24, respectively) are used for introducing a viewing scope and fluids, such as saline or other clear fluids for improving visualization of the region surrounding the left atrial appendage. In alternative embodiments, the first lumen 20 can still be used for a grasper, while either of the second lumen 22 and/or third lumen 24 may be used for introducing alternative closure devices, such as clip appliers, riveting devices, fusing devices, suturing devices, stapling devices, or the like. In a particular embodiment shown below, either or both of the lumens 22 and 24 may be used to advance a clip over the left atrial appendage as the appendage is being grasped by a grasper, such as the one shown in FIG. 3.
(18) While the closure tool may have any of a wide variety of designs, the presently preferred tool, is shown in FIG. 3A. The tool comprises a grasper 30 and a capture loop 32. Capture loop 32 is attached to a manipulation wire 34 which permits the loop 32 to be advanced over the forward end of the grasper to encircle and close the left atrial appendage, as will be described in more detail below. The grasping tool 30 may be manipulated using a thumb guide 40, while the capture loop 32 may be manipulated using a second thumb guide 42, both of which are located on the handle 18.
(19) The lumens 20, 22, and 24, terminate in exit ports 50, 52, and 54, best seen in FIG. 4A. The exit ports are located proximally of the distal end 14 of the shaft 12. The shaft is generally thinned in the region between the exit ports and the distal tip, facilitating the introduction of the distal tip into the atrioventricular groove, as described in more detail below. The exit ports are located a sufficient distance behind the distal tip of the shaft so that they will be generally located adjacent to the free end of the left atrial appendage when the tip is located in the atrioventricular groove.
(20) The methods of the present invention may be performed in an ambulatory surgical setting. Typically, a sedated patient is taken to a facility having fluoroscopic imaging capabilities. The area overlying the xiphoid and adjacent costal cartilage, is prepared and draped using standard techniques. A local anesthetic is then administered and a skin incision, usually about 2 cm in length made, at the area shown in FIG. 2. The percutaneous penetration passes beneath the costal cartilage, and a sheath 100 (FIG. 5) is introduced into the pericardial space PS. The pericardial space PS is then irrigated with saline, preferably with a saline-lidocaine solution to provide additional anesthesia and reduce the risk of irritating the heart. The closure device 10 is then introduced through the sheath 100 into the pericardial space and advanced over the epicardium to the atrioventricular groove AVG (as shown in FIG. 6A and FIG. 6B). The grasping tool 30 is then advanced distally from the tool 10 so that it can grasp the free end of the left atrial appendage LAA, as shown in FIG. 6C. A slight tension can be applied on the left atrial appendage LAA as the capture loop 32 is advanced over the grasper 30 (FIG. 6D), and on to the left atrial appendage LAA, as shown in FIG. 6E. The loop may then be cinched, as shown in FIG. 6F, and the tool 10 withdrawn leaving the closure loop in place, as shown in FIG. 6G. The interior of the left atrial appendage LAA is thus isolated from the interior of the left atrium so that thrombus and other emboli cannot be released into blood circulation.
(21) Optionally, a portion of the parietal pericardium may be further separated from the epicardial surface and the left atrial appendage prior to closing the appendage. Increasing the distance between the parietal and visceral pericardium, i.e., the pericardial space, creates a working and viewing space that facilitates subsequent manipulation and closure of the atrial appendage. As shown in FIGS. 6H-6J, a modified closure device 100 having an additional lumen 102 is introduced so that its distal end 104 enters the atrioventricular groove AVG, as described previously. A balloon expander 110 may then be introduced through the lumen 102, and the balloon expanded to raise the pericardium, as shown in FIG. 6I. The grasper 30 (or other closure instrument) may then be introduced through other lumens, as previously described. The working space created by the balloon greatly simplifies manipulation and positioning of the graspers 30 so that they can be used to capture the atrial appendage and close it as described previously. Further separating the parietal and visceral pericardia to create the working space is a particular advantage when a viewing scope is introduced to the working area to facilitate manipulation of the grasper 30 and any other tools which may be used.
(22) Referring now to FIGS. 6K-6N, the closure tool 10 is illustrated in a method for introducing a clip 200 in accordance with the principles of the present invention. The closure tool 10 is introduced to the left atrial appendage LAA as described in above in connection with FIGS. 6A and 6B. Once in place, the clip 200 may be introduced through any of the available lumens in the device, typically using a pusher 202. The clip 200 will be configured so that it opens as it emerges from the closure tool 10 and can be advanced over the free distal end of the left atrial appendage LAA, as shown in FIG. 6L. The clip 200 may then be closed over the appendage, as shown in FIG. 6N. The clip 200 may be self-closing or may require a mechanical or heat-actuated closure mechanism. Once in place, as shown in FIG. 6N, the closure tool 10 can be removed. Frequently, it will be desirable to introduce multiple clips 200, as shown in FIG. 6O. Alternatively, a larger clip 208 can be introduced transversely over the left atrial appendage LAA, as shown in FIG. 6P.
(23) Referring now to FIGS. 7A-7C, an exemplary clip 300 for use in the methods of the present invention will be described. The clip 300 has a generally U-shaped profile, as best seen in FIG. 7A, optionally having a serpentine or zig-zag profile on at least one of the legs of the clip. As illustrated, a series of peaks and valleys 302 is provided on an “upper” leg of the clip. The clip 300 further includes a hinge region 304 which has a narrowed width to facilitate introduction through a introducer catheter 400, as shown in FIG. 8. Introducer catheter 400 has a I-shaped lumen 402 which receives the clip 300 so that the upper leg and lower leg of the clip are held in an open configuration in upper and lower tracks of the lumen, as described below in connection with FIGS. 9A-9C. Optionally, the catheter 400 may include a radiopaque marker 404 to permit orientation under fluoroscopic imaging (so the position can confirm that the clip is in the proper vertical orientation when being placed). A pusher 408 is provided having a I-shaped distal end 410 which is received in the I-shaped lumen 402 in order to advance and eject the dip from the catheter.
(24) Referring now to FIGS. 9A-9C, the clip 300 is held in the lumen 402 of catheter 400 with the legs of the clip held open. A pusher 408 can be advanced so that end 410 engages the hinge region 304 of the clip, allowing it to be advanced out of the distal end of the catheter, as shown in FIG. 9B. As the clip 300 emerges, it remains in an open configuration so that it can be advanced over a free distal end of the left atrial appendage LAA, as shown in FIG. 9B. Once the clip 300 is fully advanced and released from the catheter 400, as shown in FIG. 9C, the clip will close over the left atrial appendage LAA to hold the appendage closed in accordance with the principles of the present invention.
(25) Referring now to FIG. 10, kits according to the present invention comprise a closure tool, such as closure tool 10 described above. Optionally, the kits may comprise an access sheath 120 and will include instructions for use IFU setting forth any of the methods described above. Usually, all components of the kit will be packaged together in an enclosure 140, such as a pouch, tray, box, tube, or other conventional surgical package capable of maintaining the components in a sterile condition. It will be appreciated that any kit containing instructions for use setting forth the methods of the present invention will be part of the present invention. Whether or not the kits include a closure device which is similar to FIG. 10 is not necessary.
(26) While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. Therefore, the above description should not be taken as limiting the scope of the invention which is defined by the appended claims.
