Response to “Totally anomalous systemic venous connection: Clarifying connection versus drainage”

Dear Sir, I am writing in reference to the letter “Totally anomalous systemic venous connection: Clarifying connection versus drainage.” We are thankful for the valuable comments. Here are our responses: Our case1 describes a rare systemic venous anatomy in which the child has a duplicated inferior vena cava that joins to form the hemiazygos vein, which drains into the left superior vena cava (LSVC). In the absence of the right superior vena cava, the venous return from the right upper limb is also to the LSVC via the innominate vein. The LSVC drains to the roofed coronary sinus (CS), which drains to the right atrium. The drainage of the hepatic veins, on the other hand, is anatomically and physiologically correct, which eventually enabled us to close the atrial septal defect percutaneously, avoiding open-heart surgery. Similarly, the CS drainage was also anatomically and physiologically correct, sparing the child of cyanosis and its complications. In view of the specific anatomy we encountered, we have refrained from terming this a case of “total anomalous systemic venous connection (TASVC).” As the author of the letter states, it indeed is inappropriate to equate it with a textbook case of TASVC. Instead, “total anomalous vena caval connection” seemed a more appropriate term to describe such a unique anatomy. As per the “Anatomic-physiologic classification of systemic venous anomalies” proposed by the author of the letter, our case can be classified under anomalous connection of caval veins with normal drainage, wherein the physiology of circulation within the heart is preserved.2 The term “physiological concordance of venoatrial drainage” was hence used as a descriptive term to specify the fact that the desaturated blood from all the systemic veins was eventually directed only to the pulmonary arteries. Our article did not attempt to classify the systemic venous anomaly; rather, the main focus was the challenge it posed to percutaneous closure of an atrial septal defect due to the unusual systemic venous connection. As the title of our article states, the vena caval connection is truly totally anomalous in the patient described; however, drainage was eventually normal. The reader is guided to this fact at the time of the discussion of the anatomy. We hope to have addressed all the points raised by the author of the letter “Totally anomalous systemic venous connection: Clarifying connection versus drainage,” and we will also be happy to clarify further if need be. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.