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Chapter 1 reviews the current knowledge of the aortic valve. The normal anatomy and
possible variations are described. The different pathological conditions are explained as
wel as their natural history and the indications for intervention. The various surgical options
with regard to the pathological condition are described. In particular, the results of aortic
valve
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repair, when available, are presented. All other types of aortic valve substitutes are
also described and their main advantages and disadvantages are mentioned. Finally, the
aim of the present thesis is defined.
Chapter 2 studies the durability of bicuspid aortic valve repair for prolapsing leaflet.
Ninety-four patients were operated over an 8-year period with a mean follow-up of 5 years.
Successful repair was more difficult to achieve in dilated ventricles. A total of 12 patients
underwent reoperation. In three of them, the aortic valve was re-repairable. The risk of
reoperation was highest the first postoperative year and then relatively constant at 2% per
year. The overall freedom from aortic valve reoperation was 84% at 7 years. The repair
was less durable in patients with residual aortic regurgitation after the initial procedure.
Chapter 3 examines the results of valve repair in tricuspid aortic valves with leaflet
prolapse. The repair was attempted in 33 patients but failed immediately in five. During
a mean follow-up of 4 years, three more patients required aortic valve replacement. The
freedom from aortic valve reoperation after successful initial repair was 83% at 5 years.
The size of the patient group and the number of events were too small to detect risk factors
for repair failure.
Chapter 4 is an analysis of the results of aortic valve preservation during surgical
intervention for acute Type A aortic dissection with involvement of the aortic root. From
1976 to 1999, 121 patients were operated with various techniques for aortic root
reconstruction and followed for a mean of almost 4 years. Ten percent of the patient
population underwent aortic valve replacement during follow-up but only one was due to
intrinsic aortic valve pathology. Nine reoperations were due to aortic root dilatation. The
use of fibrinous glue for aortic root reconstruction and the presence of an aortic valve
annulus > 27mm were associated with a statistically significant higher incidence of aortic
root reoperation. There was a trend towards better durability using GRF-glue® over
Teflon® felt for aortic root reconstruction.
Chapter 5 describes the initial St. Antonius Hospital experience with the aortic valve
reimplantation technique as published by David. The technique replaces the aortic root
with the exception of the aortic valve. Indications include aneurismal disease of the aortic
root or ascending aorta but also aortic wall destruction due to aortic dissection, all
complicated by (severe) aortic regurgitation. The experience with the first 13 patients was
positive. The preoperative aortic regurgitation is corrected and the patients are functionally
Summary
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markedly better postoperatively. Further follow-up of this patient group remains necessary
to evaluate the long-term outcome of this technique.
All the above techniques avoid oral anticoagulation which is one advantage of reparative
aortic valve surgery. The very long-term incidence of anticoagulation related complications
after mechanical aortic valve replacement is not well known but is an important
consideration, especially if a young adult, who still has a considerable life-expectancy,
needs aortic valve surgery. Chapter 6 therefore analyses the incidence of anticoagulation
related complications in patients who underwent a mechanical aortic valve replacement
between 1963 and 1974. Follow-up was complete at a mean of almost 20 years and revealed
that about half of the patients experienced one anticoagulation related event and 23% more
than one event. The incidence of events was highest the first 5 postoperative years and the
risk for a second event was higher than the risk for a first event. The freedom from a first
anticoagulation related event was 46.8 % at 30 years. About half of the events resulted in
a variable degree of permanent deficit.
Chapter 7 is a comprehensive discussion in which the results of the presented studies are
correlated with clinical practice.
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