Anomalous venous circuit: a detour to the heart.

We report a case of a complicated vascular access secondary to systemic venous defects, which have not been previously reported. Evaluation revealed an atypical coursing of a subclavian vein-persistent superior vena caval system into the hemizygos-azygos system and ultimately into the right (proper) superior vena cava. The clinical and surgical considerations of such an anomaly are discussed therein. We look at embryological origins of such a merger and share our experience in troubleshooting through the anomaly.