Aortic root replacement with human tissue valves in aortic valve endocarditis

Aortic allograft and pulmonary autograft aortic root replacement in native and prosthetic aortic valve endocarditis are evaluated and risk factors for hospital death are assessed by univariate risk factor analysis.

From April 1989 to May 1996, 59 patients with aortic valve endocarditis (27 native; 32 prosthetic) underwent aortic root replacement with a human tissue valve. Mean age was 53.4 +/- 12.3 years; 46 patients (78%) were male. The mean preoperative NYHA functional class was 3.4. The predominant infective organisms were streptococci (30%) in the native valve group and staphylococci (30%) in the prosthetic valve group. In native valve endocarditis, valve destruction (32%) was the predominant finding. Abscesses, either annular (29%) or subannular (36%) and valve dehiscence (36%) were the most common findings in patients with prosthetic valve endocarditis. Partial or total ventriculo-aortic discontinuity (20%) and aortico-mitral discontinuity (27%) were other important operative observations. A cryopreserved allograft was used in 53 patients (89.5%), the pulmonary autograft (Ross procedure) in 5 patients (8.5%), and a fresh antibiotic sterilized allograft root in one patient (2%). Mean aortic cross-clamp time was 131 +/- 32 min. In active native and prosthetic valve endocarditis, intravenous antibiotics were continued for at least 6 weeks, monitored by serial CRP measurements.

Hospital mortality was 8.5% (n = 5; 70% CL: 4.9-12.1%). Univariate risk factors for hospital mortality were age (P = 0.001), preoperative New York Heart Association functional class (P = 0.001), pre- (P = 0.001) and postoperative (P = 0.001) renal insufficiency. Major complications were allograft failure (n = 1; 2%), technical failure (n = 1; 2%) and false aneurysm formation at the proximal suture line (n = 1; 2%). Follow-up was complete, mean 33.1 +/- 20.1 months. Two late deaths occurred. Actuarial five year survival was 88.8% (70% CL: 80.0-97.5%); actuarial five year freedom from recurrent endocarditis was 98.1% (70% CL: 94.5-100%).

Allograft aortic root replacement is a valuable technique in the life threatening situations both of native and prosthetic aortic valve endocarditis with involvement of the annular and peri-annular region.