Impact of 3-mm Blalock-Taussig shunt in neonates and infants with a functionally single ventricle

Abstract

Functionally single ventricle (f-SV) is susceptible to volume overload. Atrioventricular valve regurgitation (AVVR) tends to develop and ventricular function deteriorates due to excessive pulmonary blood flow following modified Blalock-Taussig shunt (mBTS). On the other hand, a small caliber graft has risks of early obstruction and poor growth of pulmonary vascular beds. We assessed the effect of mBTS with a 3-mm graft to circumvent volume overload in f-SV on achievement of the right heart bypass. Eleven neonates and infants with f-SV at the median age of 24 days underwent mBTS using a 3-mm graft between August 2004 and June 2007. There were no early deaths, but there was one late death. All survivors achieved bidirectional cavopulmonary shunt (BCPS) at 4.2 months after mBTS. Cardiac catheterization demonstrated sufficient growth of the pulmonary artery (pulmonary artery index, 268+/-98 cm(2)/m(2)), low pulmonary vascular resistance (1.4+/-0.9 U.m(2)). The AVVR remained mild or less. Ventricular end-diastolic volume and ejection fraction were 171+/-61% of the normal value and 64+/-6%, respectively. We conclude that a 3-mm mBTS was useful in preventing f-SV from volume overload and was effective for growing good pulmonary vasculature and achieving a right heart bypass.

Repeated Aortopulmonary Shunt Thrombosis in a Neonatal Patient With a Low Antithrombin Level

“…In a study of 3-mm Blalock-Taussig shunts in single-ventricle neonates, Kajihara et al found a late death rate (not specified if related to thrombosis) of 1 in 11 patients studied. 7 The recurrent nature of thrombosis in our patient was unusual in our experience and is what led us to investigate for other causes. We believe the low antithrombin levels, while not the sole factor (small infant, small shunt, surgical trauma, hypoxia, and rapid fluid shifts), increased the likelihood of thrombosis.…”

Optimal Graft Size of Modified Blalock-Taussig Shunt for Biventricular Circulation in Neonates and Small Infants

“…There have been a limited number of reports on small shunts (3.0-mm graft); thus, the feasibility of these small shunts has not been widely investigated. 21) In the present series, we reduced the graft size to prevent excessive pulmonary blood flow and cardiogenic shock. A possible disadvantage of small grafts is shunt occlusion; therefore, in the operative procedure, we placed a BTS at the proximal portion of the brachiocephalic and pulmonary arteries with sufficient anastomosis size, and the median sternotomy approach was selected for all patients.…”