Summary
The aortic root as a functional unit includes the sinuses of valsalva, valve ring,
the leaflets and the commissures. This unit is impaired by the insertion of a bioprosthetic
three-leaflet valve. Moreover, bioprostheses fail because of fatigue and flexion stresses.
Consequently a program was started for free-handed orthotopic transplantation of allogeneous
aortic valves at the Department of Cardiovascular Surgery, University Kiel. A series
of 16 consecutive antibiotic, sterilized aortic valve allografts were transplanted
in the last 12 months without death, There were 4 females and 12 males between 18
and 63 years old (mean 47.9). The dominant lesion was aortic regurgitation (in 9),
Stenosis (in 3) and mixed (in 4). Out of the 13 patients who maintained their allografts,
10 (77%) were in class III and 3 (23%) in class IV of the NYHA functional Classification.
Four patients improved from class III to class I, and 9 from class III and IV to class
II of the NYHA functional Classification after surgery. All patients except one had
postoperative recatheterization including videodensitometry to quantitate the regurgitation,
expressed as a regurgitant fraction (RGF) in percent of the total stroke volume of
the left ventricle, and pressure measurements to determine systolic gradients across
the aortic valve allograft, 3 to 6 days and 9 months after surgery. Eleven (68.75%)
patients had no regurgitation, 2 (12.5%) patients had trivial aortic regurgitation
with RGF of 7% and 10%, respectively. Three (18.75%) patients had severe aortic valve
regurgitation with RGF between 40% and 60% due to technical errors and their allografts
had to be replaced. In all 3 patients the early postoperative allograft valve incompetence
was due to annulus distortion and loosely fixed new commissures. In 11 patients, the
gradient was 0 to 5 mmHg across the allograft valve, and in 2 others gradients of
10 and 15 mmHg, respectively, were observed. Immunologie and viability studies of
the ‘fresh’ stored allogeneous valves are included in the transplantation program.
The internal diameter of the patients' valve annulus and that of the allograft valve
annulus was 2 to 4 mm. Postoperatively, recorded gradients and RGF were not related
to discrepancies between the patients' annulus and the allograft valve sizes.
Key words
Aortic valve allograft - Orthotopic transplantation - Functional anatomy of aortic
root - Postoperative hemodynamic and videodensitometric study
