Conotruncal repair for tetralogy of Fallot: midterm results

Because of the left-sided location of the main atrioventricular conduction axis, the membranous flap can be safely used for closure of the ventricular septal defect in tetralogy of Fallot.

Conotruncal repair consists of (1) precise closure of the defect using the membranous flap and (2) outflow reconstruction of the right ventricle by a wide monocusp patch. This method has been followed in 233 patients from October 1985 to March 1997. The age of patients ranged from 2 months to 53 years, with a mean of 4.6 years; 44% were younger than 2 years of age, and 11% were less than 12 months of age.

A membranous flap was present in 86%, 12% had a muscle bar between the defect and the tricuspid valve, and only 2% had neither a membranous flap nor a muscle bar. There was no early death; two late deaths occurred over a mean follow-up period of 7.3 years. The actuarial survival was 99.1%. No patients required reoperation except for two with residual anomalously connecting pulmonary veins. All 233 patients were in sinus rhythm postoperatively. No patient has had a significant residual defect. The mobility of the polytetrafluoroethylene monocusp was echocardiographically detected in 85% and pulmonary regurgitation was less than mild in 82% at the late phase. The late right and left ventricular pressure ratio was 0.40 +/- 0.14 (n = 30) and the late central venous pressure was 5.6 +/- 2.2 mm Hg (n = 30).

Conotruncal repair has provided good midterm results with a low central venous pressure, well-reconstructed outflow tract of the right ventricle, no residual defect, and no heart block.