The cardiac surgery

THE VALVULAR SURGERY

- The different types of valvular prostheses
- The valvular surgery of the aorta
- The surgery of the mitral valve
- The surgery of the tricuspid valve

The valvular surgery has been considerably progressing because of the progresses achieved in the extra corporeal circulation field and the existence of better quality equipments.

The echocardiography also permitted to better assess the attacks of the cardiac valves, which contributed to widen the operative indications. Indeed, the cardiac scan (echocardiography) is now fundamental to define the “time” of the surgery, before the heart suffers too much and damages are irreversible.

The cardiac valvular surgery essentially concerns the aortic, mitral, and more seldom tricuspid valves. The surgery of the pulmonary valve is exceptional.

From a technical point of view, the surgeon has the choice, if possible, between repairing the cardiac valve (valvular plastic surgery) and replacing it with the help of a biologic or mechanical prosthesis.

The different types of valvular prostheses

a - The mechanical prostheses

They are the oldest prostheses; therefore, most of them really proved their efficiency and good tolerance.

Example of a mechanical prosthesis

Different types of prostheses exist: the ball prostheses, non-hooked single-disk prostheses, and non-hooked double-disk prostheses.

The principle of the ball prostheses consists in placing a ball into a cage whose extremities are open; one of them can close according to the heart contraction that makes the ball go up or down. This cage is positioned instead of the sick valve. These prostheses are getting much less used now.

The non-hooked single-disk valves are constituted of only one disk that “opens” the valve when it rocks.

The non-hooked double-disk prostheses are constituted of two small disks capable of mobilizing on an axis.

A few examples of cardiac valves

These mechanical valves all have a very important life span and, except in complications, they are not replaced.

Their main disadvantage is that they must be associated to the prescription of an anticoagulant treatment in the long term. Thus, a vitamin K antagonist treatment must be taken every day.

b - Biologic prostheses (bioprostheses)

The life span of these prostheses is shorter, but their enormous advantage is not to require an anticoagulant treatment in the long term.

- Two kinds of sheath-bioprostheses exist: the homografts and the heterografts

Heterograft-type bioprostheses have an animal origin (mainly porcine) and homografts bioprostheses have a human origin.

Biologic prostheses

These prostheses require the setting up of a sheath that can considerably reduce the valvular opening.

- The prostheses without a sheath (or stentless prostheses)

These prostheses are also called xenografts. They are made with the patient's tissues, mainly the pericardium (envelope surrounding the heart) or a part of the valve to be changed.

Biologic prostheses without a sheath

These prostheses offer the enormous advantage to be able to “gain” one prosthesis size compared to the sheath-prostheses, and their life span is superior.

Their main disadvantage lies in the implantation technique of these prostheses, which is often very delicate.

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File last reviewed on dec 18, 2011