Natural history of apical left ventricular to aortic conduits in pediatric patients

To determine the long-term efficacy of apical left ventricular to aortic conduits in palliating complex left ventricular outflow obstruction, we reviewed our entire experience of 20 pediatric patients who underwent placement of a composite porcine valve-bearing conduit from the left ventricular apex to the aorta from November 1977 to April 1987. There were two early postoperative deaths, both in infants less than 2 months of age at the time of surgery. The remaining 18 patients had successful conduit placement with significant relief of the left ventricular outflow obstruction. Conduits have remained functional from 3 to greater than 9 years after initial placement. Long-term maintenance of a well-functioning conduit was limited by conduit heterograft valve dysfunction secondary to degeneration and calcification, with a 3-year conduit survival of 80 +/- 9% and a 7-year survival of 52 +/- 11%. Clinical identification of conduit valve insufficiency was found to be a useful early indicator of impending conduit failure, frequently preceding other signs and symptoms of conduit valve dysfunction. Eight patients required reoperation for conduit failure, and there were two late deaths associated with conduit valve dysfunction. Other long-term complications were rare. No thromboembolic events occurred despite avoidance of anticoagulant therapy, and there were no documented episodes of bacterial endocarditis. Thus, apical aortic conduit placement is an effective surgical technique for intermediate palliation of complex left ventricular outflow obstruction and may be useful in selected pediatric patients as a staging procedure before left ventricular outflow reconstruction.