The arterial switch operation for transposition of the great arteries with left ventricular outflow tract obstruction and ventricular septal defect: clinical outcomes and specimen study.

Abstract

Objectives: In selected patients with transposition of the great arteries (TGA), ventricular septal defect (VSD), and left ventricular outflow tract obstruction (LVOTO), the arterial switch operation (ASO) may be the procedure of choice. This study reviews the clinical outcomes of TGA-VSD-LVOTO patients after ASO and compares mechanisms of LVOTO in this patient group to a historical series of cardiac specimens.

Methods: This retrospective analysis included all cases with TGA-VSD-LVOTO who underwent ASO between January 1977-December 2023. Additionally, a series of non-operated cardiac specimens with TGA-VSD-LVOTO was selected and examined for morphological comparison.

Results: Eleven patients with TGA-VSD-LVOTO underwent ASO. Eight of them had TGA-VSD, and three had Taussig-Bing anomaly. LVOTO mechanisms were multifactorial, including posteriorly deviated infundibular septum and fibrous tissue masses. Median age at ASO was 0.4 (0.07-1.8) years. Ten patients underwent primary LVOTO relief during ASO; no in-hospital mortality occurred. Two patients died >30 days post-ASO, at 3.1 months and 6.0 years. Median follow-up was 19.0 (11.1-26.8)years, all survivors in NYHA class I. The patient without initial LVOTO relief did require reoperation during follow-up for progressive LVOTO at 3.5 months post-ASO. Two patients had moderate residual LVOTO at latest follow-up (gradient 30-50mmHg). No significant neoaortic valve regurgitation was observed. From the anatomical specimen series, 10 of 33 TGA-VSD-LVOTO specimen were deemed eligible for ASO, revealing similar LVOTO mechanisms as the clinical cases.

Conclusions: ASO is feasible in selected patients with TGA-VSD-LVOTO showing good long-term outcomes with preserved neoaortic valve function and no reoperations for LVOTO after initial relief.