MIDTERM RESULTS AFTER AORTIC-VALVE REPLACEMENT WITH FREEHAND STENTLESS XENOGRAFTS - A COMPARISON OF 3 PROSTHESES

Objective: The ideal substitute for the diseased aortic valve is yet t o be found. For the assessment and comparison of the midterm results a fter aortic valve replacement with three different types of freehand s tentless xenografts, all patients who underwent the operation between October 1992 and April 1997 were reviewed, Methods: Of 231 patients un dergoing aortic valve replacement, 106 patients (group 1) were given t he Biocor PSB (Biocor Industria e Pesquisa Ltda, Belo Horizonte, MG, B razil); 76 patients (group 2) were given the Toronto SPV (St. Jude Med ical, Inc., St. Paul, Minn,), and 49 patients (group 3) were given the O'Brien-Angell valve (Bravo Cardiovascular model 300, Cryolife, Inc., Marietta, Ga.). The first two xenografts require inflow and outflow s uturelines; the third xenograft needs a single-sutureline implantation . Mean age (70 +/- 6 years; 70 +/- 7 years; 72 +/- 9 years; p = 0.6), prevalence of male sex (56 patients, 53%; 37 patients, 49%; 22 patient s, 45%; p = 0.7), of aortic stenosis (72 patients, 68%; 54 patients, 7 1%; 37 patients, 73%; p = 0.6), and need for associated procedures (51 patients, 48%; 30 patients, 40%; 21 patients, 43%; p = 0.1) were comp arable among groups. Mean aortic crossclamp time was shorter in group 3 (96 +/- 24 minutes; 100 +/- 23 minutes; 88 +/- 25 minutes;p = 0.01). Results: Early deaths were 3 of 106 (3%) in group 1, 2 of 76 (3%) in group 2, and 2 of 49 (4%) in group 3. Follow-up of survivors ranged fr om 1 to 54 months (mean 32 +/- 13 months). Survival at 4 years was 90% +/- 3% in group 1, 95% +/- 3% in group 2, 85% +/- 8% in group 3 (p = 0.3). At 4 years, freedom from valve-related events was 95% +/- 6%, 10 0%, 70% +/- 8% (p = 0.004), while freedom from valve deterioration was 99% +/- 1%, 100%, 73% +/- 8% (p = 0.001), in group 1, 2, and 3, respe ctively (p = 0.001). At follow-up, reintervention on the xenograft was necessary in one patient (endocarditis) in group 1, none in group 2, and six in group 3 (technical cause, group 3; valve tear, group 2; pan nus, group 1). Regression analysis showed O'Brien-Angell type of xenog raft to be predictive of valve-related events (p = 0.02), valve deteri oration (p = 0.001), and reoperation (p = 0.001) during follow-up. Con clusions: Midterm survival after stentless aortic valve replacement is good with all three xenografts. Freedom from valve-related events, va lve deterioration, and reoperation are excellent with the Biocor PSB o r the Toronto SPV stentless valves but less satisfactory with the O'Br ien-Angell valve.