Isolated dilatation of the inferior vena cava
A 46-year-old female underwent abdominal computed tomography (CT) imaging at a private clinic due to mild right upper quadrant abdominal discomfort and back pain during the previous 2 weeks. She was referred to our hospital to evaluate the cause of IVC dilatation shown by abdominal CT (). The patient had no history of hypertension or diabetes mellitus and no family history of aortic, collagen, vascular or congenital heart disease. She had latent hepatitis B virus infection and her mother died of hepatocellular carcinoma. Ultrasonography of the liver showed hepatic vein dilatation without obstruction or thrombus in either the hepatic vein or IVC. The abdominal CT showed prominent dilatation of the IVC and hepatic vein with no evidence of liver disease such as cirrhosis, hepatocellular carcinoma or Budd-Chiari syndrome. Her vital signs included blood pressure of 107/64 mmHg, pulse of 60 beats per minute, respiration of 20 breaths per minute, and body temperature of 36.5℃. During the physical examination, cardiac auscultation revealed no definite murmurs and her electrocardiography demonstrated no apparent ST segment or T wave abnormalities. The blood chemistry analyses were within normal limits, including N-terminal pro-B natriuretic peptide, coagulation studies with fibrinogen, antinuclear antibody, complete blood cell count, and liver enzymes. Her heart size was normal on chest X-ray. Transthoracic echocardiography was performed to evaluate right side heart abnormalities. Dilated IVC with diminished inspiratory collapse was observed (expiration 24.3 mm, inspiration 21.4 mm) using a subxiphoid approach to view the IVC along the longitudinal axis (). Spontaneous echo contrast was present in the dilated IVC without flow obstruction including the entry from the RA. The hepatic vein was dilated mildly (13.2 mm), but the flow through the hepatic vein was normal (). Tricuspid regurgitation (TR) was mild and showed normal right ventricular (RV) systolic pressure (). Normal pulmonary artery (PA) pressure without regurgitation or stenosis () and normal flow of the superior vena cava were observed. The RV size and its contractility were normal with a normal degree of tricuspid annulus displacement toward the apex in the systole (1.75 cm). Additionally, we observed normal left ventricle (LV) size and LV systolic function (ejection fraction = 68%) without regional wall motion abnormalities. Normal RA pressure, RV pressure, and PA pressure were observed (), and the RA pressure was decreased with an inspiratory effort (-2 mmHg). As the patient had no symptoms or abnormal signs, we observed her and plan to follow-up annually with echocardiography.