Hepatobiliary and Pancreatic: Atrophy‐hypertrophy complex of the liver

Abstract

A man, aged 42, was investigated because of a gradual increase in dyspnea with exercise. His past history included a car accident 18 years previously that resulted in trauma to his abdomen and chest. As a chest x-ray was abnormal, a computed tomography (CT) scan was performed that showed a diaphragmatic hernia including herniation of the liver. Various blood tests including liver function tests were normal. At operation, he had a large defect in the right hemidiaphragm with herniation of multiple organs including the liver, right colon, distal stomach and proximal duodenum. After repositioning the organs in the abdomen, the defect in the right diaphragm was closed using surgical mesh. The right lobe of the liver (RL) was small and seemed cirrhotic while the left lobe (LL) was greatly enlarged (Figure 1). A follow-up CT scan confirmed the presence of atrophy-hypertrophy complex of the liver (Figure 2). The right lobe was small and was recognized on only the most cranial CT sequences. The lateral segment of the left lobe (segment 3) was greatly enlarged, segment 4 was shown and the gallbladder (*) was in a retrohepatic position. The portal vein (white arrow), hepatic artery (thin white arrow) and common hepatic duct (thick white arrow) were also in unusual positions because of clock-wise rotation of hilar structures. The radiological features described above are typical of right lobe atrophy associated with left lobe hypertrophy. This atrophy-hypertrophy complex of the liver is almost always due to biliary obstruction or to occlusion of the portal vein. Hilar or intrahepatic causes of biliary obstruction include benign and malignant neoplasms and benign strictures including Caroli’s disease. Vascular causes include hilar or intrahepatic portal vein occlusion by neoplasms, cavernous transformation of the portal vein and congenital stenosis of the portal vein. Embolism into the right portal vein is also being used to enlarge the left lobe of the liver prior to surgical or other therapies for neoplasms in the right lobe of the liver. In animal models, a compromised portal venous blood flow is a much stronger stimulus for atrophy-hypertrophy than biliary obstruction. In the patient described above, we have attributed the atrophy-hypertrophy complex to herniation of the liver causing distortion of the right portal vein and a reduction in right portal blood flow.