Five-Year Comparison Results Between Clinically Severely Affected Tetralogy-of-Fallot Patients Initially Treated by Right Ventricular Outflow Stenting and Pink-Fallot Patients Undergoing Single-Step Correction.

The purpose: Evaluation of the short-term and long-term results of a phased correction of the tetralogy of Fallot (ToF) with stenting of the right ventricular outflow tract (RVOT) in comparison with a one-stage total correction (TC) of the defect.

Materials and methods: Two groups of patients with classical ToF were formed. Group 1 (n = 25; median age = 72 days) was initially represented by children with ToF with a more severe clinical status (median weight = 3.6 kg, with more pronounced cyanosis and with comorbidities). The children of group 1 underwent the first stage of RVOT stenting and the second stage of TC of ToF. Group 2 (n = 25) was represented by older patients, with a higher body weight and SpO2 level, and they underwent a single-stage TC of the defect.

Results: The application of a step-by-step ToF correction approach with RVOT stenting in low-weight newborns with severe hypoxemia demonstrated an equivalent effect on SpO2 dynamics-reverse remodeling of the heart-when compared with a less severe cohort of patients who underwent simultaneous TC of classical ToF. After RVOT stenting in children from group 1, the median SpO2 increased from 80% to 94.5%, the median Z value of the pulmonary artery trunk decreased from -3.46 mm to -2.54 mm, and the median index of end-diastolic volume of the left ventricle decreased from 23.07 mm/m² to 57.6 mL/m². TC of ToF in children from group 1 with a phased strategy of correction of the defect was no less successful than in children who underwent simultaneous TC. In the long-term follow-up period after TC of ToF, children from both groups, who were obviously unequal in their initial status, were practically comparable in clinical characteristics, exhibiting features of cardiac remodeling and achieving endpoints. And there were no significant differences between the two groups in the frequency of reaching the endpoints such as re-operations, cerebrovascular events, and death during the annual, three-year, and five-year follow-up period.

Conclusions: The strategy of RVOT stenting followed by TC of ToF in a severe group of children demonstrated comparable results compared with the results of simultaneous TC of ToF in a more stable group of patients during the in-hospital, annual, three-year, and five-year follow-up periods.