Annuloplasty rings for correcting degenerative valvular diseases

Abstract

A set of annuloplasty rings progressively sized to take into account more of the common pathologies. The proportional shapes of each ring as the orifice size changes vary. For instance, the larger rings have larger minor axis dimensions relative to their major axis dimensions.

Description

[0001]The present application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60 / 828,458, filed Oct. 6, 2006.FIELD OF THE INVENTION[0002]The present invention refers to a prosthetic annuloplasty ring or set of rings, in particular for the mitral annulus, that are progressively proportioned at different orifice sizes.BACKGROUND OF THE INVENTION[0003]The human heart has four valves; the aortic valve, the mitral valve, the pulmonary valve and the tricuspid valve. Various diseases and certain genetic defects of the heart valves can impair the proper functioning of the valves. Improper functioning of a valve can be severely debilitating and even fatal if left untreated, particularly if the diseased valve is the aortic valve (between the left ventricle and the aorta) or the mitral valve (between the left atrium and left ventricle). The common defects and diseases affecting each of these valves, and the treatments thereof, are typically different.[0004]The mitra...

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Benefits of technology

[0023]The set of rings is progressively sized to take into account more of the common pathologies. More specifically, the proportional shapes of each r...

Problems solved by technology

Various diseases and certain genetic defects of the heart valves can impair the proper functioning of the valves.

Improper functioning of a valve can be severely debilitating and even fatal if left untreated, particularly if the diseased valve is the aortic valve (between the left ventricle and the aorta) or the mitral valve (between the left atrium and left ventricle).

The mitral valve and, less frequently, the tricuspid valve, are prone to deformation, such as dilation of the valve annulus, tearing of the chordae tendineae and leaflet prolapse, which results in valvular insufficiency wherein the valve does not close properly and allows for regurgitation or back flow from the left ventricle into the left atrium.

Thus, because prosthetic valves have certain disadvantages that can have serious effects (e.g., mechanical valves carry the risk of thromboembolism and require anticoagulation treatment, and biological valves have limited durability), an improper functioning mitral or tricuspid valve is ideally repaired rather than replaced.

However, when the valve or its leaflets are misshapen or enlarged, for example, when the annulus is dilated, the edges of the leaflets fail to meet each other, leaving an opening therebetween.

In either case, the ineffective closure of the valve during ventricular contraction results in regurgitation or leakage of blood back into the atrium, and ultimately in reduced pumping efficiency.

Over time, this compensatory mechanism typically results in hypertrophy of the heart followed by dilation, i.e., an enlarged heart, which can lead to congestive heart failure.

Myxomatous degeneration involves weakness in the leaflet structure, leading to thinning of the tissue and loss of coaptation.

However, it is understood that four general types of structural changes of the mitral valve apparatus may produce regurgitation: leaflet retraction from fibrosis and calcification, annular dilation, chordal abnormalities (including rupture, elongation, shortening, or apical tethering or “tenting” as seen in FMR and IMR), and possibly papillary muscle dysfunction.

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