A Case of Iatrogenic Right-to-Left Shunting after Atrial Septal Defect Closure

The main causes of right-to-left shunting (RLS) in patients with atrial septal defect (ASD) are pulmonary hypertension, right ventricular outflow tract obstruction, severe tricuspid regurgitation, and a large ASD resulting in equal bi-atrial pressures. Reports of a case of an unintentional connection of the inferior vena cava (IVC) to the left atrium (LA) discovered many years after the repair of ASD are rare.

A 47-year-old male with a history of congenital ASD repair was found to have large RLS during examination of choledocholithiasis. Details of the former surgeries, performed twice for some reason, were unknown. He had cyanosis of fingers, but neither pulmonary hypertension nor right ventricular outflow obstruction. Transesophageal echocardiography, cardiac CT, and cardiac catheterization demonstrated a direct connection between the IVC and the LA as well as a residual ASD. The patient subsequently underwent successful surgical repair. It was speculated that the eustachian valve (EV) of the IVC had been wrongly taken as the lower margin of the defect in the first repair, and then a new ASD was created in the second surgery to maintain his hemodynamics. Though he had RLS with ASD, he subsequently lived a normal life for approximately 40 years, albeit with exertional dyspnea and mild cyanosis.

We report on a case of iatrogenic RLS after ASD closure. The surgeon must always check the intracardiac anatomy carefully and close the ASD without using other structures such as the EV.