Conduit reconstruction of right ventricular outflow tract. Experience with 17 patients.
Evaluation was made of 17 patients who underwent conduit reconstruction of the right ventricular outflow tract (for anomalies other than truncus arteriosus) at the Texas Heart Institute between December, 1965, and June, 1974. Fifteen patients survived the operation and have shown substantial clinical improvement. Several different conduits were used, principally an allograft aorta with the aortic valve and mitral leaflet attached, a woven Dacron prosthesis containing a xenograft (porcine) valve, and a valveless Dacron tube graft. Allograft conduits are sometimes difficult to procure and keep and tend to calcify with passage of time. Woven Dacron prostheses are favored because they are readily available in a wide range of sizes. We believe it is not necessary for the conduit to contain a valve unless the patient has pulmonary hypertension, in which case we use a xenograft (porcine) valve because this valve does not require the long-term use of anticoagulants, a difficult regimen to manage in children. The largest possible prosthesis must be used; otherwise right ventricular hypertension will persist. Indications for conduit reconstruction include anomalous coronary arteries crossing the right ventricular outflow tract, discontinuity of the pulmonary arteries, and pulmonary atresia with a ventricular septal defect. Our current method of managing pulmonary atresia with ventricular septal defect (pseudotruncus arteriosus) includes palliative shunting to relieve hypoxemia during infancy and to permit full development of the pulmonary arteries for eventual total correction at a more optimal age when a larger conduit may be used.