Tetralogy of Fallot: transannular and right ventricular patching equally affect late functional status

In tetralogy of Fallot, transannular patching is suspected to be responsible for late right ventricular dilatation.

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).

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.