Modified Blalock-Taussig shunt: immediate and short-term follow-up results in neonates

The modified Blalock-Taussig shunt (MBTS) is the most commonly created systemic-pulmonary shunt in neonates with cyanotic heart disease. Morbidity and mortality after MBTS is associated with several factors including age, pulmonary artery diameter and the baseline cardiac anatomy. The objective of this research was to describe the immediate and short-term follow-up results of MBTS in Pakistani neonates.

A retrospective review of patient charts was done to select 22 neonatal cases of various types of cyanotic heart diseases who had undergone MBTS creation from 1999 to 2005. Clinical and echocardiographic data were collected. Patients were followed up on their post-operative visits. Twenty-two neonates, 14 males and 8 females, mean age 11.2+/-6.9, underwent MBTS surgery during the six-year period of study. Pulmonary artery diameters were 3+/-0.2 and 2.9+/-0.2 for the right and left arteries, respectively. All patients received a 4mm Gor-Tex shunt through a postero-lateral thoracotomy approach. The mean duration of post-operative mechanical ventilation was 3.9+/-4.5 days. Three neonates (13.6%) died within one month of surgery while another three (13.6%) died after three months of surgery. Among these deaths, two were due to shunt occlusion/failure (9%) and the rest were due to non-cardiac causes. Another two patients underwent revision of surgery after shunt failure. Pulmonary atresia with intact interventricular septum was the most common cardiac anomaly in our series.

The mortality rate in neonates is highest during the first post-operative month. Shunt thrombosis and occlusion can be sudden and fatal therefore coagulation profile should be carefully monitored especially in the peri-operative period. PA-IVS was the most common anatomical variant in our limited experience and had high morbidity and mortality rate after surgery.