Coronary Steal Phenomenon: Adult ALCAPA with Surgical Insights and Sustainable Long-Term Outcomes

Background: Anomalous Left Coronary Artery from the Pulmonary Artery (ALCAPA), also known as Bland-White-Garland syndrome, is a rare congenital anomaly in which the left coronary artery arises from the pulmonary artery instead of the aorta. This leads to myocardial ischemia via a coronary steal phenomenon. While typically fatal in infancy, a small proportion of patients survive into adulthood due to the development of extensive collateral circulation from the right coronary artery (RCA). Prompt surgical correction is essential to prevent fatal outcomes. Case Presentation: We report the case of a 36-year-old male who presented with a one-year history of exertional angina (CCS Class II) and dyspnea (NYHA Class III). Investigations revealed ALCAPA with a dilated, super-dominant RCA, and associated partial anomalous pulmonary venous return (PAPVR) and moderate mitral regurgitation. Surgical correction was performed using the Takeuchi procedure with simultaneous mitral valve repair and PAPVR correction. The patient had an uneventful recovery. Results: The patient demonstrated marked postoperative improvement and was discharged in stable condition on postoperative day four. At two-year follow-up, cardiac CT confirmed a patent intrapulmonary baffle with no ischemic changes or mitral regurgitation. The patient remained asymptomatic and resumed normal daily activities, indicating excellent long-term functional recovery. Conclusion: This case highlights the importance of early recognition and individualized surgical planning in adult ALCAPA, particularly when associated with structural defects such as mitral regurgitation and PAPVR. The Takeuchi procedure, when appropriately applied, offers sustainable long-term outcomes and should be considered a viable option in anatomically challenging adult presentations.