LONG-TERM CLINICAL AND HEMODYNAMIC EVALUATION OF PORCINE VALVED CONDUITS IMPLANTED FROM THE RIGHT VENTRICLE TO THE PULMONARY-ARTERY

Objective: This retrospective study was initiated to evaluate the long -term results of valved prosthetic conduits implanted in the right ven tricular outflow tract in patients with complex ventricular-pulmonary discontinuity, Methods: A cohort of 103 patients out of 127 (24 early deaths, 19%) operated on between 1973 and 1996 with porcine valved con duits was available for evaluation, with a follow-up ranging from 1 to 21.6 years (mean follow-up 8.4 +/- 6 years). A total of 74 hemodynami c studies were performed after the operation, 50 patients having under gone at feast 1 cardiac catheterization during the follow-up period. R esults: There were 16 late deaths, and the actuarial survivals, includ ing early mortality, were 72.9% +/- 4% at 5 years, 63.1% +/- 5% at 10 years, and 58.2% +/- 5% at 15 years, at which time 20 patients were st ill available for review and exposed to the risk of dying. The mean pe ak systolic gradient across the right ventricular outflow tract was pl otted as a function of time, showing a gradual increase and a signific ant step-up after the eighth year, from 43 +/- 36 to 69 +/- 19 mm Hg ( P < .005), Reoperation was required for progressive conduit obstructio n between 1.1 and 17.7 years after implantation (mean 7.4 +/- 4.8 year s) in 25 patients (24%, 70% CL 15%-33%),,vith generally very few sympt oms, or for residual ventricular septal defect in 3 patients. Freedom from reoperation was 79.5% +/- 5% at 10 years and 65.8% +/- 7% at 15 y ears. Conclusions: Porcine conduits may represent a valuable alternati ve to biologic substitutes with similar long-term results. Given the f ew symptoms, progressive Conduit stenosis after the eighth postoperati ve year imposes a yearly noninvasive patient evaluation during the fol low-up.