Forty consecutive patients underwent intracardiac repair of acquired (15) and congenital (25) cardiac defects using a collagen sealed Dacron patch, baffle, or tube graft. Mean age at repair was 26.6 years (range, 1-74). Pediatric patients requiring valved extracardiac conduits were excluded from the study. Previous procedures had been done in 14 of the 40 patients (35%). There were three hospital deaths (7.5%), and two late deaths (5.4%), with an actuarial survival of 87 +/- 5.5% at 37 months after repair. Four patients required re-entry for bleeding (10%), but in no patient was bleeding related to leakage through the patch. There were no episodes of hemolysis. Mediastinitis occurred in one patient (2.7%) and resolved with usual treatment. There were no late reoperations, with actuarial freedom from reoperation 100% at 37 months after repair. The authors conclude that surgical implantation of collagen impregnated Dacron provides good early phase results. The collagen treated knitted Dacron has excellent handling characteristics and is impermeable. However, because of concerns regarding the potential for thick intimal peel formation due to variable collagen resorption rates, the authors continue to recommend pulmonary homografts when a valved extracardiac conduit is required in children.