EFFECTS OF MODIFIED AND CLASSIC BLALOCK-TAUSSIG SHUNTS ON THE PULMONARY ARTERIAL TREE

Background. The aim of this study was to assess by angiography the lat e effects of both classic and modified Blalock-Taussig shunts in terms of growth and development of stenosis and distortion. Methods. At a m ean of 51 months postoperatively, we retrospectively reviewed the resu lts in 78 patients who underwent creation of Blalock-Taussig shunts (2 5 classic and 71 modified). Results. At the level of the anastomosis, the shunt caused a reduction in diameter of the pulmonary artery in 49 % of all shunts, major stenosis (>50% narrowing of the lumen) in 14%, and distortion of the pulmonary artery in 19%, findings that did not c orrelate with the type of shunt. Distortion did correlate with younger age at the time of shunt operation (p = 0.01). Conclusions. After a B lalock-Taussig shunt, growth of the pulmonary arteries occurred but di d not exceed the normal growth of the pulmonary arterial tree. Moreove r, a shunt procedure can cause distortion and stenosis of the pulmonar y artery, which may have important implications for future corrective surgical intervention. All these findings support earlier complete sur gical repair of correctable congenital cardiac defects. (C) 1998 by Th e Society of Thoracic Surgeons.