Percutaneous Management of Right Ventricular Outflow Tract Obstruction in an Adult Patient After Atrial Switch: A Case for Targeted Infundibular Ablation

All articles of this category (opens in new window) Background: Adults after atrial switch for transposition of the great arteries may develop subaortic right-ventricular outflow tract obstruction (RVOTO) from infundibular hypertrophy. Re-operation carries an elevated risk in this population. We report a transcatheter strategy using targeted ethanol ablation of the conal branch to reduce infundibular hypertrophy and relieve obstruction. Methods: Single-patient case report. A 42-year-old woman, after atrial switch according to Mustard, presented with dyspnea and edema. Echocardiography showed a peak Doppler gradient of 93 mm Hg; the invasive peak-to-peak gradient was 90 mm Hg. After coronary mapping, sequential balloon occlusions of the right coronary conal branch were performed. Proximal occlusion lowered the gradient, supporting targeted ethanol delivery (total 1.8 mL) to the proximal conal branch. Imaging and hemodynamics were assessed at baseline and during follow-up. Results: The invasive gradient fell immediately to 20 to 30 mm Hg. Transient ST-segment changes during injection resolved. Peak troponin reached 2,106 ng/L and CK 965 U/L, both declining before discharge on day 5. At 10 months, symptoms improved, edema resolved, and there was no angina. Echocardiography showed a residual peak gradient up to 27 mm Hg (peak velocity 2.6 m/s). Cardiac MRI demonstrated late gadolinium enhancement at the targeted infundibular region with consistent systemic right-ventricular function (ejection fraction 60%). No ischemic, arrhythmic, or conduction complications were observed. Conclusion: Targeted ethanol ablation of the conal branch can be considered to reduce subaortic RVOTO in patients with a systemic right ventricle after atrial switch when surgical risk is high. A reproducible workflow—coronary mapping, stepwise occlusion testing, controlled ethanol delivery, and objective imaging follow-up—yielded durable hemodynamic and clinical benefit in this case. Further experience is needed to define long-term safety and durability in broader congenital cohorts. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany