Tetralogy of Fallot - Transannular and right ventricular patching equally affect late functional status

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 o f 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-transpulmona ry approach. To identify predictive factors of adverse long-term outcome re lated to right ventricular dilatation, the following events were investigat ed: cardiac death, reoperation for symptomatic right ventricular dilatation , and NYHA class II or III by Cox regression analysis. Mean follow-up reach ed 22+/-5 years. The 30-year survival was 86+/-5%. Right ventricular patchi ng, whether transannular or not, was the most significant independent predi ctor of late adverse event (improvement chi (2) =16.6, P<0.001). In patient s who had direct closure, the ratio between end-diastolic right and left ve ntricular 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 ri ght 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 i n a worse late functional outcome than patching of an incision limited to t he right ventricle. Both are responsible for a similar degree of long-term pulmonary insufficiency and right ventricular dilatation.