Apparatus and Methods for Occluding a Hallow Anatomical Structure

Abstract

A clamp (10) having at least first and second elongate clamping portions (2, 4) adapted to be placed on opposite sides of the hollow anatomical structure (40). The first and second elongate clamping portions (2, 4) respectively include ends coupled together with respective resilient urging members (6, 8) configured to urge at least one of the first and second elongate clamping portions (2, 4) toward the other of the first and second elongate clamping portions (2, 4) from an open position into a clamping position to occlude the hollow anatomical structure (40). The clamp (10) is shaped annularly such that it may surround the hollow anatomical structure (40) in the open position and reorient into a flattened shape in the clamping position to occlude the hollow interior of the hollow anatomical structure (40). Apparatus of the invention further include clamp delivery and actuation devices (80, 200) adapted to deploy the clamp (10).

Description

[0001]This application claims the benefit of U.S. Provisional Application Ser. No. 60 / 699,309 filed on Jul. 14, 2005, and generally relates to the subject matter disclosed and claimed in U.S. application Ser. No. 10 / 853,928, filed on May 26, 2004, the disclosures of which are hereby fully incorporated by reference herein.FIELD OF THE INVENTION[0002]The present invention relates generally to surgical methods and apparatus for occluding a hollow tissue structure, such as when occluding vessels, or pedunculated structures such as an appendix, gall bladder or appendages on the heart. More specifically, the present invention relates to a method and device for occluding the left atrial appendage of the heart in either an open surgical procedure or minimally invasive procedure.BACKGROUND[0003]Atrial fibrillation is a common cardiac rhythm disorder that affects more than two million people each year. Until relatively recently, atrial fibrillation was thought to be a nuisance arrhythmia with...

AI Technical Summary

Benefits of technology

[0015]In one aspect, the first and second elongate clamping portions and the resilient urging members may be formed from at least one wire member. The wire member may be formed from a material having superelastic properties, such as a nickel-titanium alloy, or from other materials having suitable physical characteristics for achieving the clamping function. Rigid and / or resilient tubular members may be used to cover the wire member second tubular shaped members can, for example, provide more effective load spreading by increasing the diameter of the wire member.

[0016]In another aspect of the invention, tissue blocking members are positioned at opposite ends of the elongate clamping portions and prevent outward egress of clamped tissue beyond the respective ends of the elongate clamping portions.

Problems solved by technology

However, recent medical research has uncovered some devastating complications including cardiomyopathy, congestive heart failure and stroke.

During atrial fibrillation, electrical signals from other parts of the heart disrupt the heart's normal rhythm and cause the atria to quiver or beat too fast.

This is fortunate, because a rapid ventricular heartbeat would be much more dangerous and potentially fatal.

The most significant danger is stroke.

During atrial fibrillation, the heart is not pumping normally or efficiently.

The blood begins to pool in the atria and this stagnation of blood can cause the blood to thicken and form clots.

When the heart experiences atrial fibrillation there may not be enough blood pumping to the brain or other organs.

This can cause dizziness, shortness of breath or organ failure.

Untreated atrial fibrillation will also weaken the heart due to phenomenon known as remodeling.

The fast abnormal rhythm in the atria causes electrical changes, and this can enlarge the heart.

For the prevention of blood clots, research has demonstrated that the anticoagulant warfarin (e.g., Coumadin®) is effective in reducing the risk of blood clot formation and stroke but it does not totally eliminate the risk.

An anticoagulant such as warfarin interferes with the body's natural clotting mechanism.

While this pharmacological treatment may significantly reduce the risk of stroke, it also increases the risk of bleeding and may be inappropriate for many atrial fibrillation patients.

As a result, the blood becomes thicker and thrombus or clot formation may occur.

These clots can be slowly ejected from the left atrial appendage into the left atrium and left ventricle, and then released into the bloodstream thereby becoming an obstruction in the brain or other vascular structures.

Many surgeons are uncomfortable with making an opening in this wall without being able to repair it at the end of the procedure.

There are also issues of placing an occlusion device inside the heart.

If the occlusion device becomes detached within the heart, the result may be fatal.

When trying to place a flaccid loop around an irregular pedunculated structure, it can be difficult to make certain the loop is positioned at the base of the appendage.

When cinching the loop, it is very easy to over tighten the loop, and this can result in severing the delicate atrial appendage.

Even a partial tear can create problems, including the initial problem of gaining access to repair the tear.

This method of occlusion may not always seal the opening between the appendage interior and the atrium.

That is, there may still be a partial opening due to the way the appendage wall collapses during cinching of the loop.

Such a partial opening could still allow some flow into and out of the atrial appendage, leading to the problems mentioned above.

In addition, transforming the relatively flat structure of the appendage onto a round hard mass, as does a cinching method, could lead to other problems.

Due to the limited access, the ability to visualize the entire atrial appendage while placing the stapler in the correct location can be a problem.

It is very difficult to make certain the staple line makes a complete occlusion of the appendage.

Again, a partial occlusion of the appendage can still result in the formation and dislodgement of clots.

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