Effect of Infundibular Stenosis on Growth of the Pulmonary Valve Annulus in Patients With Tetralogy of Fallot.

Objective

This study aimed to determine the effect of the degree of infundibular stenosis on growth of the pulmonary valve (PV) annulus in patients with tetralogy of Fallot (ToF).

Methods

We reviewed clinical data of all patients who underwent ToF repair between 2002 and 2022. The diameter of the infundibular area was measured before ToF repair using a lateral view of angiography at end-systole and divided by the body surface area (infundibular index [mm/m2]). The cohort was divided into two groups, a systemic-to-pulmonary artery shunt (SPS) and a primary intracardiac repair (ICR), and compared for pulmonary annular growth and the infundibular index.

Results

A total of 119 patients were included; the SPS group (n = 54) and the primary ICR group (n = 65). At ToF repair, the PV annulus was preserved in 43/65 patients (66%) in the primary ICR group and 23/54 (43%) in the SPS group (P = .0098). In a linear regression analysis, the infundibular index was significantly associated with PV growth (P < .001). The growth of the PV annulus was significantly associated with the infundibular index in both groups. In the 60 patients with a small PV annulus (Z-score < -2.0) at the initial presentation, logistic regression analysis showed that the infundibular index was the only factor significantly associated with PV preservation at ToF repair (P = .005).

Conclusion

The degree of infundibular stenosis has a significantly greater effect on pulmonary annular growth than the presence of an SPS, which may affect the preservation of the PV at the time of ToF repair.