Discovery of abnormal features of the infrahepatic portion of the inferior vena cava during a mitral percutaneous balloon commissurotomy

Introduction

Infrahepatic interruption of the inferior vena cava (IVC) with azygos or hemiazygos continuation is a rare finding.

In this anatomic entity, the intrahepatic segment of the IVC is absent, and the hepatic veins empty directly into the right atrium. Venous blood flow from the lower body is directed from the IVC into the azygos system at the level of the renal veins, with resultant dilation of the azygos and/or hemiazygos veins.

Objective

We report the case of azygos continuation of the IVC. The diagnosis was made during a catheterization during a Percutaneous Transluminal Mitral Commissurotomy.

A 56 years old female, with the history of diabetes mellitus, blood hypertension, hypothyroidism, and a mitral valve stenosis of rheumatic origin dilated 20 years ago, presented with dyspnea NYHA II. The clinical findings were: a low-pitched diastolic murmur, no sign of right cardiac failure.

Transthoracic echocardiography Show a mitrale surface in 1,3 cm². During the procedure of mitral diltation it was impossible to cross the IVC. We performed an Aortic CT-SCAN revealing aninfrahepatic interruption of the inferior vena cava (IVC) with azygos continuation.

Conclusion/Perspectives

Anomalous inferior vena cava with azygos or hemiazygos continuation is best interpreted as interruption or failure of fusion of the hepatic and prerenal segments of the inferior vena cava, combined with persistence of either the right lumbar azygos vein or left lumbar hemiazygos vein. Thus, a better term for the anomaly would be infrahepatic interruption of the inferior vena cava with azygos (hemiazygos) continuation.