Unexpected migraine improvement following surgical ligation of the right superior vena cava drainage into the left atrium: a case report.

Background: Migraines are commonly associated with cardiovascular diseases. Notable associations are found between migraines and right-to-left shunts; however, the direct causality between them remains controversial. Case summary: A 55-year-old woman with persistent hypoxaemia and over 30 years of history of migraines with aura was referred for precise evaluation. Hypoxaemia-related symptoms were limited, and physical examinations showed normal findings, with no evidence of pulmonary compromise on imaging or function tests. Contrast-enhanced computed tomography and venography revealed congenital anomalies of systemic venous return: the right superior vena cava (RSVC) draining into the left atrium (LA) and the left superior vena cava draining into the right atrium via the coronary sinus (persistent left superior vena cava). Echocardiography did not find the RSVC draining into the LA. Concerning the risk of paradoxical embolization, RSVC was surgically ligated, successfully closing the shunt. Postoperatively, hypoxaemia normalized, and the patient experienced an unexpected improvement in migraine symptoms, with a headache impact test-6 score dropping from 65 (indicating severe headache impact) to 38 (indicating minimal impact on daily life). Five years post-surgery, migraine symptoms are under control in the absence of specific medications. Discussion: Right superior vena cava drainage into the LA represents chronic hypoxaemia, but symptoms are commonly limited and may not be detected until serious brain complications develop. However, this rare congenital anomaly may, at times, be causally related to migraines with aura.