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 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 chi(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.