The surgical management of left ventricular outflow tract obstruction due to tricuspid valve pouch in complete transposition of the great arteries.

Subpulmonary stenosis in transposition of the great arteries, resulting from a tricuspid valve pouch bulging into the left ventricular outflow tract through a ventricular septal defect, can be missed at the time of operation in the flaccid, nonbeating heart unless preoperative diagnosis has been established. In our experience, six patients were found to have this lesion. In four patients the tricuspid valve pouch was recognized preoperatively. At operation, retraction of the tricuspid valve pouch into the right ventricle, patch closure of the ventricular septal defect, and a Mustard procedure were performed in three patients; the fourth is awaiting correction following initial palliation with a subclavian-pulmonary shunt. In the other two, the ventricular septal defect was partially or completely obliterated by a tricuspid valve pouch that was missed preoperatively and during exploration at the time of the Mustard procedure. Residual left ventricular outflow tract obstruction was subsequently corrected with a left ventricle-pulmonary artery valved conduit. Echocardiographic and angiocardiographic examinations offer helpful signs for the diagnosis of tricuspid valve pouch. Transatrial retraction of the redundant tricuspid valve tissue into the right ventricle, patch closure of the ventricular septal defect, and Mustard operation are the procedures of choice. A left ventricle-pulmonary artery valved conduit may be required for residual unresectable left ventricular outflow tract obstruction.