Clinical and pathological features of accessory valve tissue

Background. Accessory valve tissue is a rare congenital cardiac malformation causing a variety of clinical features. We describe our experience with the surgical treatment of accessory valve tissue to clarify clinical and pathological features of this anomaly. Methods. Between December 1990 and February 1999, 11 children underwent resection of accessory valve tissue together with repair of coexisting intracardiac malformations. Eight patients had accessory tricuspid valve, while 3 had accessory mitral valve tissue. Associated intracardiac malformations included tetralogy of Fallot in 6 patients, transposition of the great arteries in 3, coarctation complex in 1, and ventricular septal defect in 1. Results. Accessory valve tissue was completely resected in all but 1 patient with accessory mitral valve and transposition of the great arteries. As total resection of the accessory valve tissue through the pulmonary artery was unsuccessful, partial resection and bidirectional Glenn shunt operation was performed instead of arterial switch operation in this patient. Conclusions. The clinical signs and symptoms of accessory valve tissue vary according to its location and coexisting cardiac malformations. Congenital heart surgeons should be familiar with the clinical and pathological features of accessory valve tissue, so as not to overlook it during operation.