Assessment of the pulmonary arterial growth and results of two-stage repair in infants with severe form of tetralogy of Fallot

Abstract

Aim: assess of the pulmonary artery growth and the outcomes of complete repair after palliative treatment in infants with critical form of Tetralogy of Fallot.Methods. This was prospective randomized two-center study (2019 to 2022). Its included infants with Tetralogy of Fallot who underwent palliation with either stenting of the right ventricular outflow tract (stent group, n=21) or modified Blalock-Taussig shunt (shunt group, n=21).Results. In the stent group Nakata index increase from median 104.2 to 208.6 mm2/m2, while in the shunt group, it increased from 107.3 to 169.4 mm2/m2 (p<0,01). Mixed model analysis showed that in stent group the right pulmonary artery growth rate was 2.05*10-2 z scores/day, which was 3.01 times higher than in the shunt group. In stent group the left pulmonary artery growth rate was 2.3*10-2 z scores/day, which was 1.47 times higher than in the shunt group. In the stent group, there was one noncardiac-related mortality during the intermediate period. Transannular patch repair of the right ventricular outflow tract was performed in 12 patients (60%) in the stent group and in 15 patients (71.4%) in the shunt group (p=0.52) during complete repair. At 8 cases (40%) in the stent group and 6 cases (28.6%) in the shunt group, pulmonary artery replacement was performed. Time to surgical repair was shorter in the stent group (p=0.046), while the aortic cross clamp time (p<0,01) and cardiopulmonary bypass time (p<0,01) were significantly shorter in the shunt group.Conclusions. Right ventricular outflow tract stenting provides hemodynamic stabilization and uniform growth of the pulmonary artery compared to modified Blalock-Taussig shunt.

Keywords

• tetralogy of fallot
• pulmonary artery hypoplasia
• two-stage repair
• stenting of the right ventricular outflow tract
• modified blalock-taussig shunt