[Left superior vena cava simulating abnormal pulmonary venous return].

Abstract

The case of a seven year old boy with coarctation of the aorta and a left superior vena cava (SVC) draining into the left atrium is reported. Usually, in this condition the circulation is centripedal, descending from the left SVC to the left atrium and leading to systemic cyanosis or desaturation. In this case, the circulation was centrifugal and ascending from the left atrium to the left SVC to the innominate vein, leading to a left-to-right shunt as in abnormal pulmonary venous return. The left-to-right shunt flow was 4.2 l/mn and the ratio of pulmonary to systemic flow was 1.8: there was no pulmonary hypertension. This type of circulation is very rare and only two other cases were found in the literature. It may be explained by the proximity of the left pulmonary veins to the left SVC and by a functional mitral obstacle due to the increased pulmonary return. Simultaneous correction of the coarctation and ligature of the left SVC was carried out by left thoracotomy without cardiopulmonary bypass.