A case report of an interrupted inferior vena cava and azygos continuation: Implications for preoperative screening in minimally invasive cardiac surgery

Background: Femoral cannulation is commonly used in minimally invasive cardiac surgery to establish extracorporeal circulation. We present a case with a finding that should be evaluated when screening candidates for minimally invasive cardiac surgery. Case summary: A 57-year-old male patient was scheduled for minimally invasive repair of the mitral and tricuspid valve and a MAZE procedure. During surgery there was difficulty advancing the venous cannula inserted in the right femoral vein. On transoesophageal echocardiography a guidewire advanced from the femoral vein was observed entering the right atrium from the superior vena cava. Despite inserting a second venous cannula in the jugular vein, venous drainage was insufficient for minimal invasive surgery. The approach was converted to a median sternotomy with bicaval cannulation. Re-examination of the preoperative computed tomography (CT) scan showed an interrupted inferior vena cava (IVC) with azygos continuation. Discussion: In patients with major venous malformations such as the interrupted IVC with azygos continuation a full sternotomy is the preferred approach. The venous system should be evaluated when screening candidates for minimally invasive mitral valve surgery with preoperative CT. Additional cues to suspect interruption of the IVC are polysplenia and a broad superior mediastinal projection on the chest radiograph, mimicking a right paratracheal mass.