Surgical treatment of straddling tricuspid valves.

Abstract

Six patients whose cardiac malformations included a large ventricular septal defect (VSD) in the inlet portion of the septum and straddling tricuspid valve underwent corrective intracardiac operations. In 4 patients, both the tricuspid valve annulus and its tensor apparatus occupied part of each ventricle. In 1, only the annulus overrode the ventricular septum and in 1 the annulus was normally positioned, but a portion of the tensor apparatus crossed through the VSD from its origin in the left ventricle. This last patient had related mitral valve incompetence. A patient had an isolated VSD and 1 had isolated, multiple VSD and a previously banded pulmonary artery. Associated malformations in the other 4 included tetralogy of Fallot, double outlet right ventricle, transposition of the great arteries with severe tricuspid incompetence and corrected transposition. Hypoplasia of the sinus portion of the right ventricle was present to some degree in 4 patients. Preoperatively the diagnosis was definitively established by axial cineangiocardiograms in 3 and suspected in 1. The straddling tricuspid valve was preserved in the repair in 5 patients but tricuspid valve replacement was used in the patient with severe tricuspid incompetence. In 1 case, intraoperative electrophysiologic mapping studies were performed and showed abnormal conduction pathways. Patients (5) survived the hospital period. Postoperative cardiac catheterization studies were performed in 4, 1 of whom died 16 mo. postoperatively from chronic congestive heart failure. The remaining 4 survivors have had a good clinical result.