Biomedical Engineering Reference
In-Depth Information
5
Percutaneous cardiovascular
valve replacement
T. MODINE, A. SUDRE, T. GOURLAY and
J. C. LABORDE, Centre Hospitalier Régional
Universitaire de Lille, France
Abstract
: Many patients with severe aortic stenosis do not undergo
surgery because of excessive risk or advanced age. Percutaneous valve
implantation has been under active investigation by a number of groups.
Percutaneous heart valves are now, in selected patients, a reliable
technology with potential benefi t for many. Further studies, and technical
and procedural enhancements are required to assure reliable and safe
prosthesis delivery, positioning, deployment, and durability.
Key words
: aortic, valve, percutaneous.
5.1
Introduction
Aortic valve diseases comprise aortic stenosis and/or aortic regurgitation.
Accounting for the vast majority of aortic valve disease, aortic stenosis has
a prevalence of around 1-2% in those aged over 65 and 4% in those over
85. It is mainly due to calcifi c stenosis on the bicuspid valve, senile degen-
eration, or rheumatic disease. Aortic valve regurgitation affects approxi-
mately fi ve out of every 10 000 people. Common etiologies include rheu-
matic fever, dystrophic lesions of the ascending aorta, and infectious endo-
carditis. The inevitable progress of the disease leads to surgical valve
replacement, which consists of implantation of either a mechanical or a
biological prosthesis (heterograft or allograft) via thoracotomy.
1-7
This pro-
cedure requires both general anesthesia and cardiopulmonary bypass,
which can lead, particularly in the aging population, to disorders in vital
functions (heart, brain, and kidneys). Moreover, owing to the high compli-
cation rate and discomfort to the patient, and to frequent associated poly-
visceral illnesses, there are still some patients who are not suitable candi-
dates for a conventional open-heart procedure and hence remain untreated.
These are the reasons why there has been an increase in research in recent
years in an attempt to develop a less invasive approach to valve replace-
ment. Nevertheless, given the outstanding results of open valve repair and
replacement, conventional surgery is likely to remain the gold standard for
most patients with symptomatic valvular heart disease.
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