Left hepatic vein (LHV) that drains blood into a coronary sinus (CS) is an extremely rare congenital anomaly of systemic vein drainage with only single reports published. In most of these cases the unusual venous connection was found incidentally during diagnostics or surgery.

The case of a two-year-old boy in whom the anomaly was discovered during open heart surgery for partial anomalous pulmonary venous drainage (PAPVD) is presented. Difficulties in obtaining proper diagnosis preoperatively are confronted with postoperative echo findings.

Embryology and evolution of sinus venosus are discussed to explain the persistent connection between hepatic venous circulation and a coronary sinus. The authors attempt to recapitulate the possible surgical consequences of LHV-CS continuity.