Xenograft transplantation in congenital cardiac surgery at Baskent University: midterm results

Xenograft valved conduits have been used in several cardiac pathologies. In this study we have presented our midterm results of pediatric patients pathologies who were operated with xenograft conduits.

Between January 1999 and January 2005, 134 patients underwent open heart surgery with xenograft conduits. The conduits were used to establish the continuity of the right ventricle to the pulmonary artery or aorta, the left ventricle to the pulmonary artery, or aorta due to various types of complex cardiac anomalies. Patients were evaluated by transthoracic echocardiography (ECHO) at 6-month follow-ups. Cardiac catheterization was performed when ECHO demonstrated significant conduit failure.

Hospital mortality was observed in 28 patients (20.1%), and 13 patients died upon follow-up (9.7%). Mean follow-up was 24.6 +/- 4 months (range, 13 to 85 months). Among 93 survivors 20 patients (21.5%) were reoperated due to conduit failure. The main reasons for conduit failure were stenosis (n=13), valvular regurgitation (n=2), or both conditions in 5 cases. Mean pulmonary gradient before conduit re-replacement was 47.7 +/- 30.1 mmHg. The 1-, 3-, and 6-year actuarial survival rates were 95 +/- 2%, 91 +/- 3%, and 86 +/- 5%. The 1-, 3-, and 6-year actuarial freedom rates from reoperation were 95 +/- 1%, 90 +/- 3%, and 86 +/- 4%. An increased gradient between the pulmonary artery and the right ventricle and prolonged cardiopulmonary bypass times were observed to be significant risk factors for reoperation. There was no mortality among reoperated patients.

Xenograft conduits should be closely followed for calcification and stenosis. Conduit stenosis is the major risk factor for reoperation. In these patients, reoperation for conduit replacement can be performed safely before deterioration of cardiac performance.