Aortic allograft and pulmonary autograft for aortic valve replacement: mid-term results

Abstract

Between April 1990 and August 1996, 138 patients (median age 42 years, range 10 days to 66 years) underwent aortic valve or root replacement with allografts ( n=70) or autografts ( n=68). Aortic stenosis was the main indication (80 patients, 58%) followed by aortic incompetence (31 patients, 22%). Twenty-five patients had endocarditis (18%) and two patients had truncus repair (2%). Some 140 allograft valves were inserted (70 pulmonary, 70 aortic). Most of the valves were conditioned and cryopreserved by the European Homograft Bank, Brussels, Belgium. Subcoronary implantation was performed in 46 patients, intraluminal cylinder in 29 and root replacement in 63. Peroperative transoesophageal echocardiography was routinely used. Three patients required valves replacement by mechanical valves at the time of surgery due to technical failure. Seven patients (5%) died early, while 131 were followed up from 1 to 76 months (mean 32 months). There were two late deaths. All survivors are in NYHA class I and currently free of any medication. There have been no thromboembolic events. Three patients developed endocarditis (2%). Transthoracic echocardiography was performed routinely in all patients; an initial study showed grade 1 aortic incompetence in nine patients and grade 2 in two. Late studies up to 6 years after surgery showed progression of aortic incompetence in 18 of 43 survivors with subcoronary implantation and in four of 75 survivors who underwent other techniques ( P<0.002). In congenital patients with preoperative aortic incompetence, the left ventricular function has been prospectively analysed by echocardiography. Risk factors have been identified as dilated ventricles with spherical shapes, thin wall and reduced velocities by measuring ejection fraction and velocity of shortening of myocardial fibres. Allograft and autograft replacement of the aortic valve can be performed with excellent results. Considering the risk of degeneration of allografts, and the growth potential of the pulmonary autograft, this should be regarded as the optimal method of treatment for diseased aortic valves in neonates, children and young adults.