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Valvular Heart Disease: Difference between revisions
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The first cardiac valve surgery under direct vision was an aortic valve replacement, performed in 1960 by dr. Dwight Harken <cite>Stephenson</cite> The aortic valve was replaced by a caged ball valve, which became the standard for aortic valve replacement. <cite>Emery</cite> <cite>Chaikof</cite> | The first cardiac valve surgery under direct vision was an aortic valve replacement, performed in 1960 by dr. Dwight Harken <cite>Stephenson</cite> The aortic valve was replaced by a caged ball valve, which became the standard for aortic valve replacement. <cite>Emery</cite> <cite>Chaikof</cite> | ||
A total of more than 70 different mechanical aortic valve models have been introduced in aortic valve replacement and implanted in humans in the past 5 decades. The mechanical prostheses can be divided into 3 large groups: the first generation of ball valves, second generation of tilting-disc valves, and the last generation of bileaflet valves. <cite>Vitale</cite> | |||
In 1962 Donald Ross implanted the first aortic valve allograft. In 1967 he replaced a patient’s malfunctioning aortic valve with the patients own pulmonary valve. An aortic or pulmonary valve homograft was then used to replace the patient’s pulmonary valve. This procedure is known as the Ross Procedure. Currently, the Ross procedure may be considered for bicuspid aortic valve stenosis, particularly for young women of reproductive age. | |||
=== Transcatheter intervention === | |||
In 2002, the first transcatheter aortic valve implantation was performed by dr. Alain Cribier. A transcatheter aortic valve implantation is a less invasive treatment option for patients at prohibitive risk for conventional aortic valve replacement. In this technique, the native valve is not excised. After balloon valvuloplasty, the prosthetic valve is implanted in the aortic position, with the frame of the prosthesis covering the native valve. The bioprosthesis can be implanted retrograde or antegrade. Currently 4 different approaches may be used in this technique (See [table reference]). Transcatheter aortic valve implantation is assessed in randomized clinical trials and registries. | |||
== Prognosis == | |||
Aortic valve stenosis has a severe prognosis when any symptoms are present, with survival rates of only 15–50% at 5 years. Strongest predictors of poor outcome in the elderly population are high New York Heart Association (NYHA) class (III/IV), associated mitral regurgitation and left ventricular dysfunction. Survival is only 30% at 3 years with the combination of these three factors. | |||