Aortic Valve Replacement with Small-Sized Disc Prostheses
(Medtronic Hall)
Antonio J. Brazao MD , David Prieto MD, J Ferrao de Oliveira MD,
Luis Eugenio MD, Manuel J. Antunes MD

A total of 332 patients each with an aortic valve annulus <21 mm were implanted with small (size 20, 21 and 22) Medtronic-Hall prostheses. The mean patient body surface area was 1.59 ± 0.12 m² (range: 1.27-2.01 m²). The mean systolic left ventricular/aorta gradient was 64.5 ± 24.8 mmHg before surgical correction. After surgery, peak gradients through the prostheses were 13.9 ± 8.0 mmHg in size 20 prostheses, 14.0 ± 8.1 mmHg in size 21, and 10.1 ± 8.9 mmHg in size 22. Four patients (1.2%) died in hospital. The late mortality rate was 9.3% (n = 31); of these patients, 20 (14.3%) had received size 20 prostheses, seven (7.3%) size 21, and four (4.2%) size 22. Fourteen patients (4.2%) died of cardiac causes, but only six (1.8%) of prosthesis-related causes. Our experience demonstrates that the small Medtronic-Hall prostheses have good hemodynamic performance and offer an excellent option as valve substitutes in patients with narrow aortic roots.