Method and apparatus for performing a procedure on a cardiac valve

Abstract

The present invention comprises a method for deploying an aortic valve prosthesis. This valve prosthesis may include any of the known aortic valves including, but not limited to, stented and unstented bioprosthetic valves, stented mechanical valves, and expandable or self-expanding valves, whether biological or artificial. The method involves the steps of: making a first opening leading to the left atrium; passing a valve prosthesis through the opening and into a cardiac chamber of the left side of the heart using a first manipulation instrument; making a second opening in the arterial system and advancing one end of a second manipulation instrument through the arterial opening and into the aforementioned cardiac chamber; securing the second manipulation instrument to the valve prosthesis; and using the second manipulation instrument to retract at least some portion of the valve prosthesis out of the aforementioned cardiac chamber.

Description

REFERENCE TO PENDING PRIOR PATENT APPLICATION [0001] This patent application claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 60 / 215,245, filed Jun. 30, 2000 for CARDIAC VALVE PROCEDURE METHODS AND DEVICES, which patent application is hereby incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] Of all valvular heart lesions, aortic stenosis carries the worst prognosis. Within one year of diagnosis, approximately half of all patients with critical aortic stenosis have died, and by three years, this figure rises to approximately 80%. Currently, the most prominent and effective treatment for patients with aortic stenosis is aortic valve replacement via open heart surgery. Unfortunately, this procedure is a substantial and invasive undertaking for the patient. [0003] While there have been significant advances in heart valve technology over the past 30 years, there has been little progress in the development of safer and less invasive valve deliv...

AI Technical Summary

Benefits of technology

[0030] The pressure of blood flowing through the left atrium is very low, peaking at a few inches of water during the cardiac cycle. This pressure is a small fraction of that found within the arterial system and thus permits insertion of a conventional valve prosthesis through a relatively large opening formed in the wall of the left atrium without the risk of uncontrollable bleeding. In this respect it will be appreciated that various methods are known to those skilled in the art for controlling bleeding from an incision into the left atrium. The left atrium also rarely suffers from atherosclerotic plaque formation or calcification, thus minimizing the risk of embolic debris during such incision.

[0031] Another aspect of the present invention is the use of a prosthesis holding apparatus for releasably holding the valve prosthesis during manipulation to its implant site. The prosthesis holding apparatus may be secured to the prosthetic valve at any suitable location(s) through the use of any of a variety of approaches including, but not limited to, suture loops, barbs, hooks, grasping jaws, opposing magnetic poles, friction fits and the like. The prosthesis holding apparatus is configured to provides first and second manipulation mounts for engagement by the aforementioned first and second manipulation instruments, respectively, whereby the prosthetic valve can be delivered to its implant site. This construction is highly advantageous in that it permits the valve prosthesis to be passed easily and reliably from the first manipulation instrument to the second manipulation instrument within the vascular system.

Problems solved by technology

Unfortunately, this procedure is a substantial and invasive undertaking for the patient.

While there have been significant advances in heart valve technology over the past 30 years, there has been little progress in the development of safer and less invasive valve delivery systems.

Given the current invasiveness of this procedure and the requirement to utilize cardiopulmonary bypass, aortic valve replacement surgery is associated with a high risk of morbidity and mortality.

Using the technology available at that time, success was limited: the valve area was increased only minimally, and nearly all patients had restenosis within one year.

However, these approaches still require cardiopulmonary bypass and cardiac arrest, which themselves entail significant morbidity and a prolonged post-operative recovery.

Unfortunately, although there has been great progress in the treatment of coronary artery disease without cardiopulmonary bypass (e.g., angioplasty, with or without stenting, and “off-pump” coronary artery bypass grafting), similar advances have not yet been realized in heart valve surgery.

The first challenge is to remove the diseased valve without causing stroke or other ischemic events that might result from the liberation of particulate material while removing the diseased valve.

The second challenge is to prevent cardiac failure during removal of the diseased valve.

However, as the diseased valve is removed, it becomes acutely and severely incompetent, causing the patient to develop heart failure which results in death unless the function of the valve is taken over by another means.

Therefore, any sizable incision made to the aorta in order to insert a standard valve prosthesis into the arterial system creates the potential for uncontrollable bleeding from the incision site.

Furthermore, even if bleeding is successfully controlled, pressures within the aorta may result in weakening of the aorta caused by aortic wall dissection.

In addition, large incisions on the aorta also increase the potential for liberating plaque from the aortic wall that can lead to embolic complications.

Unfortunately, however, none of these relatively flimsy valve prostheses have proven adequate to endure the repetitive stresses undergone by the aortic valve over the ten to twenty years typically required.

In addition to the foregoing, the precise placement of such expandable prosthetic valves in the correct sub-coronary position can be extremely challenging, particularly in view of the high pressure, pulsatile blood flow passing through the aorta.

Furthermore, expandable prosthetic valves would typically be positioned from a remote artery, which would reduce the ability to precisely control the placement and positioning of the device and therefore would increases the risk of obstructing the coronary arteries.

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