Modifiedversus classical blalock-taussig shunts for congenital cyanotic heart diseases: A comparison of long-term results

Abstract

Between March 1977 and December 1984, 103 Blalock-Taussig shunts were performed on 88 patients. Included in this study were 40 patients who underwent the modified BT shunt and 63 patients who underwent the classical BT shunt. 13 of the modified BT shunts (33 per cent) and 18 of the classical BT shunts (29 per cent) were performed during infancy and 10 of the modified BT shunts (25 per cent) were performed on patients under the age of 3 months. EPTFE grafts of varying sizes were used in the patients who underwent modified BT shunts—4 mm in 14 cases, 5 mm in 15 cases and 6 mm in 11 cases, respectively. The early mortality rate was 11 per cent (3 deaths) in the group who had modified BT shunts and 8 per cent (5 deaths) in the group who had classical BT shunts. Over a follow-up period of 6 years, 6 shunt failures were diagnosed in the modified BTS group by auscultation and/or angiographic study, and during a follow-up period of 8 years, 12 shunt failures were diagnosed in the classical BTS group. The patency rate 3 years after surgery was 88.8 per cent in the modified BTS group and 78.0 per cent in the classical BTS group. The patency rate 5 years after surgery was 88.8 per cent in the modified BTS group and 75 per cent in the classical BTS group. No significant differences were noted in the patency rates between the modified and classical BTS groups during the period of 5 years' follow-up, however, the former patency rate does appear to be slightly superior to the latter. This study confirms that where an EPTFE graft of larger than 5 mm in diameter was used, the modified BT shunt is the procedure of choice as a palliative treatment in patients with cyanotic congenital heart defects who will only be able to have corrective surgery several years later.