A Route Less Traveled: Anomalous Venous Drainage of the Right Heart.

Congenital anomalies of the coronary sinus and veins have been well documented, but only one instance of an anomalous small cardiac vein draining into the superior vena cava (SVC) has been reported. The majority of patients with anomalies of the coronary venous system are asymptomatic, but these variants are important to document as they may have clinically significant implications in the management and possible interventions patients may receive. This report describes an anomalous connection from the coronary venous system to the superior vena cava discovered incidentally in a patient with SVC syndrome and end-stage renal disease (ESRD). This may reflect a congenital variant which accommodated collateral flow to bypass the fully occluded SVC. Alternatively, it may be the result of repeated venoplasty of the stenotic SVC which opened an iatrogenic tract that was maintained and vascularized over time.