Comparative Study on the Outcomes of Right Ventricular Outflow Tract Stenting vs. Modified Blalock-Taussig Shunt in Patients with Tetralogy of Fallot: A Prospective Randomized Trial.

Objective: To evaluate pulmonary vascular development and outcomes of complete correction following palliative treatment in infants with critical tetralogy of Fallot.

Methods: This prospective, randomized, two-center study included infants with tetralogy of Fallot who underwent surgery between June 2018 and 2022. The patients were divided into two groups - those who underwent stenting of the right ventricular outflow tract (stent group, n=21) and those who underwent modified Blalock-Taussig shunt placement (shunt group, n=21).

Results: In the stent group, a significantly greater increase in Nakata index was observed, with mean values rising from 104.2 to 208.6 mm2/m2, compared to an increase from 107.3 to 169.4 mm2/m2 in the shunt group (P<0.01). According to the mixed model analysis, the rate of growth of the right pulmonary artery in the stent group was 2.05*10-2 z score/day, which was 3.01 times greater than that in the shunt group (P<0.01). The rate of growth of the left pulmonary artery in the stent group was 2.3*10-2 z score/day, which was 1.47 times greater than that in the shunt group (P<0.01). In one patient (4.8%), after 76 days following the stenting of the RVOT, a severe infectious process with sepsis occurred, leading to a fatal outcome. Complete correction in the stent group involved transannular patch repair of the right ventricular outflow tract to the pulmonary artery in 12 patients (60%), while the same procedure was performed in 15 patients (71.4%) in the shunt group (P=0.52).

Conclusion: Stenting of the right ventricular outflow tract provides hemodynamic stabilization and symmetric growth of the pulmonary vascular bed compared to the formation of a modified Blalock-Taussig shunt.