Agnes of inferior vena cava is a rare abnormality that occurs in less than 1% of the population. The origin of the inferior vena cava is a complex process that occurs between the sixth and eighth week of gestation. When the process of formation of the vena cava incompletely occurs or it does not occur, we have a compensatory dilatation of the azygos system to help the venous drainage of the lower segment of the body.1,2
A 59 year old man, referred to the Hepatology Unit of investigation for ascites having heavy past alcoholic habits (> 200 g/day) and a history of deep vein thrombosis in the left leg, chronic renal ne-phropathy caused by diabetic and hypertensive which led to hemodialysis. Objectively, patients without signs of hepatic encephalopathy, jaundice mucosa, with ejection systolic murmur II/VI of cardiac auscultation, without stasis lung, large volume ascites, exuberant collateral circulation, umbilical hernia and lower extremity edema with signs of venous chronic insufficiency (Figure 1). It was submitted to abdominal ultrasound, endoscopy, viral serology, liver function tests as well as with peritoneal fluid study. Having ascites and no data to justify the existence of cirrhosis and portal hypertension, led to performing abdominal ultrasound with Doppler for screening of a possible obstruction of venous drainage. The abdominal Doppler ultrasound does not see the inferior vena cava and the angio-CT confirmed the agenesis of the inferior vena cava associated with moderate ascites and collateral circulation tho-racoabdominal (Figure 2).
