Coarctation of the aorta with total anomalous pulmonary venous connection: a case report

Total anomalous pulmonary venous connection (TAPVC) and coarctation of the aorta (CoA) rarely occur together. In affected patients, blood is supplied to the lower body by saturated ductal flow. Preoperative echocardiography may not show an acceleration of flow at the isthmus (coarctation), and the oxygen saturation (SpO₂) at the feet may be satisfactory. Consequently, the severity of CoA is often underestimated before performing surgery. A 6-day-old boy weighing 2.6 kg with a diagnosis of supracardiac TAPVC was referred for surgical correction of his anomaly. The atrial septal defect (ASD) was 6.7 mm in diameter. There was a large patent ductus arteriosus (PDA) without flow acceleration at the preductal entry into the descending aorta. Only the TAPVC repair was planned, but immediately following ligation of the large PDA, the blood pressure in the lower extremity dropped to around 30 mmHg. The ligation was removed. The reason for the blood pressure discrepancy between the upper and the lower body was not clear as there was no arterial line in the upper extremity and a 6.7-mm-diameter ASD can support sufficient blood flow to the lower body without the PDA. A suspected CoA was found and repaired, followed by the TAPVC repair. Caution is necessary when repairing a TAPVC and coexisting large PDA as the severity of the CoA can easily be underestimated due to nonsignificant flow acceleration.