Tetralogy of Fallot

Background —In tetralogy of Fallot, transannular patching is suspected to be responsible for late right ventricular dilatation. Methods and Results —In our institution, 191 patients survived a tetralogy of Fallot repair between 1964 and 1984. Transannular patching was used in 99 patients (52%), patch closure of a right ventriculotomy in 35, and direct closure of a right ventriculotomy in 55. Two had a transatrial-transpulmonary approach. To identify predictive factors of adverse long-term outcome related to right ventricular dilatation, the following events were investigated: cardiac death, reoperation for symptomatic right ventricular dilatation, and NYHA class II or III by Cox regression analysis. Mean follow-up reached 22±5 years. The 30-year survival was 86±5%. Right ventricular patching, whether transannular or not, was the most significant independent predictor of late adverse event (improvement χ 2 =16.6, P <0.001). In patients who had direct closure, the ratio between end-diastolic right and left ventricular dimensions on echocardiography was smaller (0.61±0.017 versus 0.75±0.23, P =0.007), with a smaller proportion presenting severe pulmonary insufficiency (9% versus 40%, P =0.005). There was no difference between right ventricular and transannular patching concerning late outcome (log rank P value=0.6), right ventricular size (0.70±0.28 versus 0.76±0.26, P =0.4), or incidence of severe pulmonary insufficiency (30% versus 43%, P =0.3). Conclusions —In tetralogy of Fallot, transannular patching does not result in a worse late functional outcome than patching of an incision limited to the right ventricle. Both are responsible for a similar degree of long-term pulmonary insufficiency and right ventricular dilatation.