[A rare case of congenital tricuspid stenosis treated with modified Fontan operation].

A rare case of congenital tricuspid stenosis treated with modified Fontan operation was reported. The patient was 13 years old boy and his chief complaint was cyanosis. Cyanosis appeared in his neonatal period and squatting developed in his childhood. He underwent Blalock's shunt operation at 5 years of age. His exercise tolerance was limited at the admission for the radical operation. Angiocardiography showed the annular stenosis of tricuspid valve and the moderate hypoplasia of right ventricle. The right ventricular volume was 56 ml (equivalent to 35% of the normally expected right ventricular volume) and the diameter of tricuspid annulus was 13 mm (equivalent to 58% of the normally expected diameter). Atrial septal defect was associated with but pulmonary stenosis did not exist. His left ventricular function was good and pulmonary vascular resistance was not raised. A diagnosis of tricuspid stenosis was made and Fontan's repair was considered to be possible for his correction. Operative findings showed normal architecture of tricuspid valve with the three leaflets but tricuspid annulus was narrow. Tricuspid valve stenosis was considered to be caused by the hypoplasia of tricuspid ring and surgical dilatation was found to be difficult. Therefore, modified Fontan operation (RA-RV connection) was performed. His cyanosis disappeared and exercise tolerance was improved after the operation. Cardiac catheterization and angiocardiography were performed 8 months and 28 months after the operation. His righ ventricular volume was increased to 123 ml (equivalent to 57% of the normally expected volume) followed by RA-RV connection.