Novel Transaortic and Right Atrial Approach for Pediatric Tunnel-Type Left Ventricular Outflow Tract Obstruction: Preserving Right Ventricular Function

Background: Tunnel-type left ventricular outflow tract obstruction (LVOTO) is a rare and surgically complex congenital anomaly in pediatric patients, particularly in cases complicated by prior failed interventions and fibromuscular scarring. We report early outcomes of a novel transaortic and right atrial approach designed to preserve right ventricular (RV) function while enabling complete resection of deep-seated stenoses. Methods: Between 2012 and 2023, 26 pediatric patients (mean age 5.4 ± 1.3 years; 14 boys, 12 girls), including 9 (34.6%) with previous failed septal myectomy, underwent surgical correction for tunnel-type LVOTO at three tertiary centers in Türkiye. The procedure involved transaortic resection with controlled iatrogenic ventricular septal defect (VSD) creation, followed by right atrial-guided VSD closure. Outcomes—including left ventricular–aortic (LV–Ao) pressure gradient, RV function, and reoperation—were assessed over a median follow-up of 4.6 years (range: 1–8 years). Results: There were no 30-day or late mortalities. The mean LV–Ao gradient decreased significantly from 67.6 ± 11.9 mmHg to 15.8 ± 5.0 mmHg postoperatively (p < 0.0001), with comparable outcomes in reintervention (16.5 ± 5.7 mmHg) and primary (15.3 ± 4.6 mmHg) groups (p = 0.557). Postoperative right ventricular function was well preserved (FAC reduction: 0.5–5%; TAPSE reduction: 0.2–1.5 mm; p < 0.05). Right bundle branch block occurred in 6 patients (23.1%), all asymptomatic. Only one patient (3.8%) required reoperation for aortic insufficiency, yielding 96.2% freedom from reoperation at 5 years. Conclusion: The transaortic and right atrial approach achieves significant LV–Ao gradient reduction and preserves RV function in pediatric patients with tunnel-type LVOTO, demonstrating efficacy even in reintervention cases with prior failed septal myectomy. Larger, multicenter studies with extended follow-up are warranted to validate long-term safety and durability.