The Annals of Thoracic Surgery, Vol 41, 272-275, Copyright © 1986 by The Society of Thoracic Surgeons
The midterm and long-term results of the Mustard operation in patients with transposition of the great vessels and dynamic left ventricular outflow tract obstruction
S Stewart, PJ Harris and J Manning
Eight of 43 patients with transposition of the great vessels (TGV) and
either an intact ventricular septum or very small ventricular septal defect
were found to have dynamic left ventricular outflow tract obstruction
(LVOTO). The preoperative left ventricle-pulmonary artery (LV-PA) pressure
gradient ranged between 14 and 60 mm Hg. In 3 patients the pulmonary artery
could not be catheterized. They had a left ventricular pressure of 43, 45,
and 62 mm Hg, respectively, no evidence of pulmonary vascular disease, and
either echocardiographic or angiocardiographic demonstration of LVOTO. The
outflow tract was explored in 3 patients at the time of the Mustard
operation. Exposure of the LVOT was difficult, particularly in patients
less than 6 months of age. A shallow septal myectomy was performed in 1
patient; a thin fibrous endocardial scar was resected in 2; and no
procedure was performed in the third. All 8 patients survived and remain
asymptomatic 1 to 11 years (mean, 5 years) after operation. The LV-PA
pressure gradient has either remained the same or has increased in every
patient except 1 in whom there was a slight reduction in the gradient. We
conclude that dynamic LVOTO persists after the Mustard operation and is not
amenable to direct surgical relief. However, an excellent clinical result
can be obtained for up to 11 years after operation.
