The Hancock external valved conduit. A dichotomy between late clinical results and late cardiac catheterization findings.

The Hancock external valved conduit was inserted in 18 children between 1974 and 1977. Seventeen patients survived operation and 15 are long-term survivors of 6 to 9 years. All patients have been closely followed up by the same pediatric cardiologist and each has undergone serial cardiac catheterization studies, generally performed at 1 and 6 years after operation. All long-term surviving patients have been in either New York Heart Association Class I or II. A few continue to take digoxin or diuretics. Cardiac catheterization demonstrated a gradient of 50 mm Hg or greater across the conduit in two of 16 patients 1 year after operation and in seven of 15 patients 6 years after operation. Five patients (30% of all long-term survivors) have had this conduit replaced and each has survived reoperation. The finding of a severe conduit gradient in one third of all long-term surviving patients is particularly bothersome since these patients were essentially asymptomatic. This study emphasizes the need for serial follow-up cardiac catheterization studies in all patients who receive the Hancock conduit.