Impact of Systemic Pulmonary Shunt for Tetralogy of Fallot on Pulmonary Valve Annulus Growth and Midterm Pulmonary Valve Function.

BACKGROUND

Tetralogy of Fallot (TOF) often requires transannular patch repair, leading to pulmonary regurgitation. Systemic pulmonary shunt can be associated with pulmonary valve annulus (PVA) growth, thus potentially enabling valve-sparing repair. This study evaluated PVA growth after systemic pulmonary shunt and the midterm impact of valve-sparing repair on pulmonary valve function.

METHODS

We reviewed 54 patients with TOF who underwent staged repair with systemic pulmonary shunt. PVA z scores were compared before and after systemic pulmonary shunt. Freedom from pulmonary regurgitation (PR) was assessed. Freedom from PR was defined as PR less than moderate.

RESULTS

The median follow-up duration after intracardiac repair was 7.6 years (interquartile range [IQR], 3.1-10.8 years). In the staged repair group, the median PVA z score increased from -3.4 (IQR, -5.2 to -2.6) at the time of systemic pulmonary shunt to -2.7 (IQR, -4.4 to -1.8) before intracardiac repair. Freedom from PR at 8 years after intracardiac repair was higher in the valve-sparing repair group (84% vs 45%; P = .009). The pre-systemic pulmonary shunt PVA z score was a significant predictor of PVA growth (odds ratio, 1.87; P = .002), with a threshold of -4.1 predicting growth with 82.1% sensitivity and 72.7% specificity.

CONCLUSIONS

PVA growth was observed in patients with TOF after systemic pulmonary shunt. The pre-systemic pulmonary shunt PVA z score predicts successful growth and informs surgical planning. Valve-sparing repair offers superior midterm freedom from PR compared with transannular patch repair.