Anesthetic Management of Delayed Primary Arterial Switch Operation in a Two-Month-Old Infant With Dextro-Transposition of the Great Arteries (d-TGA), Preserved Left Ventricular Mass, and Patent Ductus Arteriosus: A Case Report.

For dextro-transposition of the great arteries (d-TGA) with an intact ventricular septum, the arterial switch operation (ASO) is usually performed early to avoid left ventricular (LV) deconditioning. When infants present late, the risk of postoperative LV failure rises substantially. In this case report, we describe a two‑month‑old infant (3.98 kg) with d‑TGA, severe hypoxemia (peripheral oxygen saturation (SpO2) 49%), and failure to thrive. Despite late presentation, LV mass and its circular geometry were maintained (ejection fraction 85.1%) in association with a large, nonrestrictive 6.1 mm patent ductus arteriosus (PDA). A primary ASO was completed successfully. Anesthesia was managed with a total intravenous anesthesia technique using high-dose opioids. During separation from cardiopulmonary bypass, milrinone (0.5 mcg/kg/min) and low-dose epinephrine (0.05 mcg/kg/min) were administered to enhance myocardial contractility while optimizing the balance between systemic and pulmonary vascular resistances (SVR and PVR) to prevent low cardiac output syndrome and reactive pulmonary hypertensive crises. The patient remained hemodynamically stable postoperatively. In this selected late-presenting infant, primary ASO was feasible alongside preserved LV mass and geometry in the presence of a large PDA. Comprehensive preoperative echocardiography and tailored anesthetic management focusing on biventricular loading and PVR/SVR balance are key to achieving favorable outcomes.