1. Field of the Invention
The present invention relates generally to medical methods and apparatus. More particularly, the present invention relates to a method and device for the minimally invasive closure of a left atrial appendage of the heart.
Atrial fibrillation is a common cardiac rhythm disorder affecting a population of approximately 2.5 million patients in the United States alone. Atrial fibrillation results from a number of different causes and is characterized by a rapid chaotic heart beat. In addition to the risks associated with a disordered heart beat, patients with atrial fibrillation also have an increased risk of stroke. It has been estimated that approximately 75,000 atrial fibrillation patients each year suffer a stroke related to that condition. It appears that strokes in these patients result from emboli many of which may originate from the left atrial appendage. The irregular heart beat causes blood to pool in the left atrial appendage, allowing clots to accumulate over time. From time to time, clot may dislodge from the left atrial appendage and may enter the cranial circulation causing a stroke, the coronary circulation causing a myocardial infarction, the peripheral circulation causing limb ischemia, as well as other vascular beds.
Significant efforts have been made to reduce the risk of stroke in patients suffering from atrial fibrillation. Most commonly, those patients are treated with blood thinning agents, such as coumadin, to reduce the risk of clot formation. While such treatment can significantly reduce the risk of stroke, it also increases the risk of bleeding and for that reason is inappropriate for many atrial fibrillation patients.
As an alternative to drug therapy, surgical procedures for closing the left atrial appendage have been proposed. Most commonly, the left atrial appendage has been closed or removed in open surgical procedures, typically where the heart has stopped and the chest opened through the sternum. Because of the significant risk and trauma of such procedures, left atrial appendage removal occurs almost exclusively when the patient's chest is opened for other procedures, such as coronary artery bypass or valve surgery.
For that reason, alternative procedures which do not require opening of the patients chest, i.e., a large median stemotomy, have been proposed. U.S. Pat. No. 5,306,234 to Johnson describes a thoracoscopic procedure where access to the pericardial space over the heart is achieved using a pair of intercostal penetrations (i.e., penetrations between the patient's ribs) to establish both visual and surgical access. While such procedures may be performed while the heart remains beating, they still require deflation of the patient's lung and that the patient be placed under full anesthesia. Furthermore, placement of a chest tube is typically required to reinflate the lung, often requiring a hospitalization for a couple of days.
U.S. Pat. No. 5,865,791, to Whayne et al. describes a transvascular approach for closing the left atrial appendage. Access is gained via the venous system, typically through a femoral vein, a right internal jugular vein, or a subclavian vein, where a catheter is advanced in an antegrade direction to the right atrium. The intra-atrial septum is then penetrated, and the catheter passed into the left atrium. The catheter is then positioned in the vicinity of the left atrial appendage which is then fused closed, e.g., using radiofrequency energy, other electrical energy, thermal energy, surgical adhesives, or the like. Whayne et al. further describes a thoracoscopic procedure where the pericardium is penetrated through the rib cage and a lasso placed to tie off the neck of the left atrial appendage. Other fixation means described include sutures, staples, shape memory wires, biocompatible adhesives, tissue ablation, and the like. The transvascular approach suggested by Whayne et al. is advantageous in that it avoids the need to penetrate the patient's chest but suffers from the need to penetrate the intra-atrial septum, may not provide definitive closure, requires entry into the left atrial appendage which may dislodge clot and requires injury to the endocardial surface which may promote thrombus formation. A thoracoscopic approach which is also suggested by Whayne et al. suffers from the same problems as the thoracoscopic approach suggested by Johnson.
For all these reasons, it would be desirable to provide improved and alternative methods and procedures for performing minimally invasive closure of the left atrial appendage. Such methods and procedures will preferably be capable of being performed on patients who have received only a local anesthetic and whose hearts have not been stopped. It would be further desirable to provide methods and procedures which approach the left atrial appendage without the need to perform a thoracotomy (penetration through the intracostal space) or the need to perform a transeptal penetration and/or perform the procedure within the left atrium or left atrial appendage. More specifically, it would be preferable to provide methods and procedures which permitted access to the pericardial space from the xiphoid region of a patient's chest. In addition to the improved and alternative methods and procedures, it would be desirable to provide specialized instruments, devices, and systems for accessing a region over a patient's left atrial appendage from a sub-xiphoid access point to permit closure of the left atrial appendage.
At least some of these objectives will be met by the inventions described herein below.
2. Description of the Background Art
U.S. Pat. Nos. 5,306,234 and 5,865,791 have been described above. U.S. Pat. No. 3,496,932 and PCT publication WO 98/05289 describe methods and apparatus which employ a sub-xiphoid approach for direct cardiac massage.
The present invention provides alternative and improved methods and apparatus for closing a left atrial appendage of a patient, particularly a patient at risk of occlusive stroke resulting from emboli released from the left atrial appendage. The most likely patient population for the procedures will be patients suffering from atrial fibrillation which can result in clot and thrombus generation in the left atrial appendage, as described above. The methods and apparatus of the present invention permit procedures to be performed on a conscious sedated patient, often in an ambulatory surgical setting where the patient may be released shortly after the procedure is completed. In particular, the methods and apparatus of the present invention eliminates the need for a large incision and division of the sternum, i.e., median sternotomy. The present invention further eliminates the need to take down (deflate) a lung to access a left atrial appendage, as is usually required in thoracoscopic procedures performed via intracostal access.
The methods of the present invention will be performed in a minimally invasive manner, i.e., where access to the pericardial space overlying the patient's left atrial appendage is accomplished through percutaneous penetrations through the patient's skin. Rather than passing through the rib cage, as with prior thoracoscopic techniques, the present invention relies on a “sub-xiphoid” approach where the percutaneous penetration is first made beneath the rib cage, preferably between the xiphoid and adjacent costal cartilage, and an atrial appendage closure tool advanced through the penetration, over the epicardial surface (in the pericardial space) to reach a location adjacent to the exterior of the left atrial appendage. The closure tool can then be used to close the left atrial appendage to prevent the formation of clot and the release of emboli from the atrium.
Closure can be effected in a variety of ways. It is presently preferred to position a loop of material, such as suture, wire, mesh, tape, or the like, over the appendage and cinch the loop tighter to close the interior of the appendage. A variety of alternative closure techniques would also find use, including suturing (using remotely actuated suturing instruments), stapling, clipping, fusing, gluing, clamping, riveting, or the like. Such closure will generally be intended to be permanent, i.e., it will remain indefinitely after the closure tool is removed, but in some instances could be reversible, i.e., the left atrial appendage could be reopened on a subsequent procedure.
Thus, a method according to the present invention for closing a left atrial appendage of a patient's heart comprises positioning a closure instrument through a percutaneous passage beneath the rib cage, over an epicardial surface, and adjacent to the left atrial appendage. The left atrial appendage is then closed, usually using one of the techniques described above. The positioning step may comprise making an incision usually between a costal cartilage and a xiphoid of the patient, establishing a tract beneath the rib cage. Alternatively the incision may be made superficial to the xiphoid or sternum after which a tract is made through the rib cage to the pericardial space, and will preferably include placing an access sheath through the incision into the pericardial space. The incision may be made using a scalpel or other conventional surgical tool, but could also be made using a trocar and cannula assembly, such as those used in Iaparoscopic surgery, where the trocar could then be removed leaving the cannula in place as the sheath of the present invention. Use of a trocar and cannula may be less preferred, however, since there is an increased risk of injuring the heart if the trocar and cannula assembly is introduced in a blind fashion.
A closure instrument is then introduced through the sheath into the pericardial space, and over an epicardial surface to the exterior of the left atrial appendage, as described above. Preferably, a distal end of the tool will be introduced into an atrioventricular groove which lies just beneath the atrial appendage.
Preferably, once the closure tool has been introduced, advancement and positioning can be performed under conventional imaging techniques, such as fluoroscopic imaging. Often, the closure tool will include or be compatible with imaging scopes which may be introduced through the tool. The use of imaging scopes will be particularly useful during the closure procedure where the left atrial appendage is manipulated as described in more detail below. In such instances, it will frequently be desirable to introduce a saline or other clear fluid into the pericardial space to facilitate viewing.
Once the closure tool is properly positioned, closure may be effected by any of the techniques described above, including looping, suturing, stapling, clipping, fusing, clamping, riveting, or the like. Preferably, the closure will be directed at the base region of the left atrial appendage. Optionally, closing the appendage may further comprise grasping the exterior of the left atrial appendage prior to the actual closing step. Grasping will typically be performed with the conventional grasping tool. As described below, a preferred closure technique is to first grasp the exterior of the left atrial appendage with a grasping tool and subsequently advance a closure loop over the tool on to the exterior of the appendage. A closure loop may then be cinched or otherwise closed or allowed to close, and the tools removed.
A variety of specific instruments, devices, and systems may be devised for performing the methods of the present invention. An exemplary device for closing a left atrial appendage according to the methods of the present invention is described in detail in the descriptions that follow. The device comprises a shaft having a proximal end and a distal end, where the distal end is adapted to percutaneously enter the pericardial space, be advanced over an epicardial surface, and then approach the exterior of the left atrial appendage. Preferably, the shaft has a length in the range from 10 cm to 40 cm, a width in the range from 2 mm to 20 mm, and a thickness in the range from 1 mm to 10 mm. Usually, the shaft will be curved over its length to be compatible with the curvature of the heart. The shaft may include a means to alter the curvature to accommodate variations in anatomy. Similarly, the device may preferably include a crescent-shaped cross-section to also conform to the shape of the exterior of the heart. The device will carry a mechanism or means for closing the left atrial appendage when the distal end of the shaft is positioned adjacent to the appendage. Usually, the closure mechanism will be introducable through one or more lumens formed in the shaft. In a particularly preferred configuration, the distal end of the shaft will be configured to lie within the atrioventricular groove of the heart, and at least one lumen through the shaft will have an exit port spaced inwardly from the distal end of the shaft by a distance in the range from 0.5 cm to 5 cm. In this way, the port will be positioned properly to access the free end of the atrial appendage for performing the closing procedures. In addition, the shaft may have one or more additional lumens (for a total of two, three, or more lumens through the shaft) in order to provide additional capabilities, including introduction and use of a viewing scope, infusion and perfusion of fluids, particularly the infusion of saline to facilitate viewing. Optionally, the lumens can be used to introduce an anesthetic agent, such as lidocaine, in order to reduce pain or to introduce an anti-arrhythmic agent to reduce myocardial irritability.
The present invention still further comprises kits including the closure devices just described. The kits will further include instructions for use according to the methods described above, and optionally further include packaging for holding all components of the kit together. Additionally, the kits may include the access sheath which is placed through the percutaneous penetration tracks as the pericardial space. The access sheath may be in the form of a trocar and cannula assembly, although this will usually not be preferred.
Referring now to
An exemplary tool 10 for performing the methods of the present invention is illustrated in
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
While the closure tool may have any of a wide variety of designs, the presently preferred tool is shown in
The lumens 20, 22, and 24, terminate in exit ports 50, 52, and 54, best seen in
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
Optionally, a portion of the parietal pericardium may be farther 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
Referring now to
Referring now to
Referring now to
Referring now to
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.
This application is a divisional application of application Ser. No. 10/007,364 filed Nov. 5, 2001 which is a divisional application of application Ser. No. 09/315,601, filed on May 20, 1999 now U.S. Pat. No. 6,488,689 and both of these applications are incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
3496932 | Prisk et al. | Feb 1970 | A |
3703169 | Ouchi | Nov 1972 | A |
3896793 | Mitsui et al. | Jul 1975 | A |
4030509 | Heilman et al. | Jun 1977 | A |
4217891 | Carson | Aug 1980 | A |
4257278 | Papadofrangakis et al. | Mar 1981 | A |
4280510 | O'Neill | Jul 1981 | A |
4319562 | Crosby | Mar 1982 | A |
4369768 | Vukovic | Jan 1983 | A |
4579348 | Jones | Apr 1986 | A |
4662377 | Heilman et al. | May 1987 | A |
4706655 | Krauter | Nov 1987 | A |
4759348 | Cawood | Jul 1988 | A |
4765341 | Mower et al. | Aug 1988 | A |
4817608 | Shapland et al. | Apr 1989 | A |
4841949 | Shimizu et al. | Jun 1989 | A |
4934340 | Ebling et al. | Jun 1990 | A |
4944753 | Burgess et al. | Jul 1990 | A |
4991578 | Cohen | Feb 1991 | A |
4991603 | Cohen et al. | Feb 1991 | A |
4998975 | Cohen et al. | Mar 1991 | A |
5033477 | Chin et al. | Jul 1991 | A |
5144942 | Decarie et al. | Sep 1992 | A |
5163949 | Bonutti | Nov 1992 | A |
5181123 | Swank | Jan 1993 | A |
5230705 | Wilk | Jul 1993 | A |
5234455 | Mulhollan | Aug 1993 | A |
5243977 | Trabucco et al. | Sep 1993 | A |
5269326 | Verrier | Dec 1993 | A |
5306234 | Johnson | Apr 1994 | A |
5336231 | Adair | Aug 1994 | A |
5336252 | Cohen | Aug 1994 | A |
5373840 | Knighton | Dec 1994 | A |
5385156 | Oliva | Jan 1995 | A |
5423821 | Pasque | Jun 1995 | A |
5433730 | Alt | Jul 1995 | A |
5498228 | Royalty et al. | Mar 1996 | A |
5520701 | Lerch | May 1996 | A |
5582580 | Buckman, Jr. et al. | Dec 1996 | A |
5634895 | Igo et al. | Jun 1997 | A |
5676162 | Larson, Jr. et al. | Oct 1997 | A |
5676651 | Larson, Jr. et al. | Oct 1997 | A |
5678547 | Faupel et al. | Oct 1997 | A |
5681278 | Igo et al. | Oct 1997 | A |
5682906 | Sterman et al. | Nov 1997 | A |
5683445 | Swoyer | Nov 1997 | A |
5693091 | Larson, Jr. et al. | Dec 1997 | A |
5702430 | Larson, Jr. et al. | Dec 1997 | A |
5707336 | Rubin | Jan 1998 | A |
5716392 | Bourgeois et al. | Feb 1998 | A |
5725521 | Mueller | Mar 1998 | A |
5728151 | Garrison et al. | Mar 1998 | A |
5752526 | Cosgrove | May 1998 | A |
5766189 | Matsuno | Jun 1998 | A |
5769848 | Wattanasirichaigoon | Jun 1998 | A |
5797870 | March et al. | Aug 1998 | A |
5797946 | Chin | Aug 1998 | A |
5799661 | Boyd et al. | Sep 1998 | A |
5800414 | Cazal | Sep 1998 | A |
5823946 | Chin | Oct 1998 | A |
5827216 | Igo et al. | Oct 1998 | A |
5840059 | March et al. | Nov 1998 | A |
5861005 | Kontos | Jan 1999 | A |
5865791 | Whayne et al. | Feb 1999 | A |
5871531 | Struble | Feb 1999 | A |
5879375 | Larson, Jr. et al. | Mar 1999 | A |
5882299 | Rastegar et al. | Mar 1999 | A |
5895298 | Faupel et al. | Apr 1999 | A |
5897586 | Molina | Apr 1999 | A |
5900433 | Igo et al. | May 1999 | A |
5908429 | Yoon | Jun 1999 | A |
5910124 | Rubin | Jun 1999 | A |
RE36269 | Wright | Aug 1999 | E |
5931787 | Dietz et al. | Aug 1999 | A |
5941819 | Chin | Aug 1999 | A |
5947953 | Ash et al. | Sep 1999 | A |
5961440 | Schweich, Jr. et al. | Oct 1999 | A |
5964699 | Rullo et al. | Oct 1999 | A |
5968010 | Waxman et al. | Oct 1999 | A |
5984866 | Rullo et al. | Nov 1999 | A |
5984917 | Fleischman et al. | Nov 1999 | A |
5991668 | Leinders et al. | Nov 1999 | A |
5997525 | March et al. | Dec 1999 | A |
6006122 | Smits | Dec 1999 | A |
6015382 | Zwart et al. | Jan 2000 | A |
6059750 | Fogarty et al. | May 2000 | A |
6071281 | Burnside et al. | Jun 2000 | A |
6081738 | Hinohara et al. | Jun 2000 | A |
6083153 | Rullo et al. | Jul 2000 | A |
6090042 | Rullo et al. | Jul 2000 | A |
6095968 | Snyders | Aug 2000 | A |
6110170 | Taylor et al. | Aug 2000 | A |
6120431 | Magovern et al. | Sep 2000 | A |
6148230 | KenKnight | Nov 2000 | A |
6149595 | Seitz et al. | Nov 2000 | A |
6152936 | Christy et al. | Nov 2000 | A |
6155968 | Wilk | Dec 2000 | A |
6157852 | Selmon et al. | Dec 2000 | A |
6162195 | Igo et al. | Dec 2000 | A |
6167889 | Benetti | Jan 2001 | B1 |
6199556 | Benetti et al. | Mar 2001 | B1 |
6200303 | Verrior et al. | Mar 2001 | B1 |
6206004 | Schmidt et al. | Mar 2001 | B1 |
6221007 | Green | Apr 2001 | B1 |
6224584 | March et al. | May 2001 | B1 |
6237605 | Vaska et al. | May 2001 | B1 |
6241667 | Vetter et al. | Jun 2001 | B1 |
6258021 | Wilk | Jul 2001 | B1 |
6266550 | Selmon et al. | Jul 2001 | B1 |
6283127 | Sterman et al. | Sep 2001 | B1 |
6293906 | Vanden Hoek et al. | Sep 2001 | B1 |
6296630 | Altman et al. | Oct 2001 | B1 |
6311692 | Vaska et al. | Nov 2001 | B1 |
6311693 | Sterman et al. | Nov 2001 | B1 |
6312404 | Agro et al. | Nov 2001 | B1 |
6314962 | Vaska et al. | Nov 2001 | B1 |
6314963 | Vaska et al. | Nov 2001 | B1 |
6319201 | Wilk | Nov 2001 | B1 |
6333347 | Hunter et al. | Dec 2001 | B1 |
6338737 | Toledano | Jan 2002 | B1 |
6352503 | Matsui et al. | Mar 2002 | B1 |
6488689 | Kaplan et al. | Dec 2002 | B1 |
Number | Date | Country |
---|---|---|
0 317 490 | May 1989 | EP |
WO9805289 | Feb 1998 | WO |
9817187 | Apr 1998 | WO |
0016850 | Mar 2000 | WO |
Number | Date | Country | |
---|---|---|---|
20020099390 A1 | Jul 2002 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 10007364 | Nov 2001 | US |
Child | 10105978 | US | |
Parent | 09315601 | May 1999 | US |
Child | 10007364 | US |