[Inferior vena caval return to the left atrium with intact interauricular septum. Apropos of 2 cases surgically treated with success]. / Retour veineux cave inférieur dans l'oreillette gauche à septum interauriculaire intact. A propos de deux cas opérés avec succès.

Two cases of abnormal inferior vena caval return to the left atrium are reported in a 9 year old boy and 13 year old girl. The diagnosis was suspected on the finding of severe cyanosis alone, and the anomalous systemic venous return was correctly identified by angiography of the inferior vena cava. There were three angiographic points of interest in these two cases: the normal position of the inferior vena cava, the absence of a left-to-right interatrial shunt and the presence of a vertical intra-left atrial "membrane" inserted behind the orifice of the inferior vena cava. Surgical correction consisted in resecting the inferior part of the interatrial septum and reconstructing a new septum behind the orifice of the inferior vena cava with a dacron patch in one case and by direct suture in the other. The good surgical result was controlled by angiography in both cases. In the second case, an intrapulmonary shunt due to multiple arteriovenous fistulae demonstrated by contrast echocardiography was responsible for persistent mild cyanosis for a few months after surgery. The long-term clinical results were excellent in both cases. The authors review the literature of this rare malformation due to persistence of part of the right valve of the sinus venosus.