Surgery – Instruments – Suture – ligature – elastic band or clip applier
Reexamination Certificate
1999-05-20
2002-12-03
Recla, Henry J. (Department: 3731)
Surgery
Instruments
Suture, ligature, elastic band or clip applier
Reexamination Certificate
active
06488689
ABSTRACT:
BACKGROUND OF THE INVENTION
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 patient's chest, i.e., a large median sternotomy, 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 patients 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.
SUMMARY OF THE INVENTION
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 vari
Bajor Jordan T.
Kaplan Aaron V.
Cook Alex McFarron Manzo Cummings & Mehler, Ltd.
Ho Tan-Uyen T.
Kaplan Aaron V.
Recla Henry J.
LandOfFree
Methods and apparatus for transpericardial left atrial... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods and apparatus for transpericardial left atrial..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods and apparatus for transpericardial left atrial... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2985328