Dual drainage total anomalous pulmonary venous connection: a rare mixed variant

Abstract

The mixed type of total anomalous pulmonary venous connection is the least common variant, occurring in approximately 5% of all patients. Dual drainage through a common venous confluence is much rarer. Computed tomography to delineate the exact pulmonary venous anatomy is a must in such cases. Correct preoperative recognition and intraoperative confirmation to check the drainage of all 4 pulmonary veins is essential in all cases of total anomalous pulmonary venous connection. We report the case of an adult patient with dual drainage to coronary sinus and left vertical vein to innominate vein.

Totally anomalous “double drainage” of pulmonary venous confluence: case report with embryological aspects

“…Careful observation of prior reported cases in literature shows that the vascular channel described in these patients as a common confluence is not a true single tubular channel in the sagittal body axis, which could have developed from an embryological confluence. [4][5][6][7] Our patient had double drainage of a single vascular channel in sagittal body axis, draining all four pulmonary veins (a pattern most fitting to the embryologically described common pulmonary vein) into the left superior caval vein and coronary sinus.…”

“…8 Drainage has also been reported to other sites like left brachiocephalic vein and right superior caval vein; portal vein and right superior caval vein and via two orifices into left superior caval vein. 4,7,9 Our patient also had a co-existent significant right superior caval vein stenosis close to its entry into the right atrium, thereby leading to obstruction to drainage at supra-cardiac level.…”

“…Mixed type of total anomalous pulmonary venous connection (defined as drainage of pulmonary veins into systemic venous side at multiple levels) is rare, accounting for less than 5% of patients with total anomalous pulmonary venous connection. 4 The embryological basis of mixed drainage can be possibly explained by an insult at earlier period in gestation, resulting in persistence of aberrant connections at more than one level. 5 An extremely rare variant of total anomalous pulmonary venous connection, which is not separately classified in widely used "Darling" system, is "double drainage" type (being currently classified as a variant of mixed total anomalous pulmonary venous connection).…”

Double drainage of total anomalous pulmonary venous connection: An extremely rare variant

“…TAPVC results due to the persistence of the embryonic connections of the pulmonary venous plexus with the umbilical, vitelline, and cardinal venous systems. Dual drainage of pulmonary veins (into cardiac and supracardiac levels) is an extremely rare mixed variant of TAPVC with only a few case reports 1 . The diagnosis is usually made on echocardiography.…”

“…Dual drainage of pulmonary veins (into cardiac and supracardiac levels) is an extremely rare mixed variant of TAPVC with only a few case reports. 1 The diagnosis is usually made on echocardiography. However, this case highlights the critical role of dual-source CT angiography in accurately identifying the course of the veins, the separate drainage sites or any stenosis/obstruction.…”