Experimental atrophy/hypertrophy complex of the liver after portal and/or biliary ligature in the rat
Patients with lobar or segmental, benign or malignant strictures of the biliary tree (with or without impairment of the portal blood flow) show a considerable atrophy of the involved area of the liver with a compensatory hypertrophy/hyperplasia of the remaining non affected liver. To investigate the importance of the biliary and portal obstruction for the development of this process, we used a rat model, with selective biliary and/or portal ligation of the anterior liver lobes (two thirds of the liver mass). Weight measurements, morphometry, functional scintigraphy (Hepatoiodida-scan) and blood enzyme analyses were done immediately postoperatively, at 30 hours and 4, 8 and 28 days after the operation. The major findings were: 1. 28 days after biliary and/or portal ligation there was no difference between the body weight of the four groups, all ligated animals having compensated for an initial greater percentage body-weight loss. 2. Total liver weight remained constant, while atrophy and hypertrophy/hyperplasia occurred although a progressive derangement of liver morphology was observed during that time. 3. A severe atrophy-hypertrophy-complex (AHC) developed after selective portal ligation, which in our experiment did not appear after selective biliary ligation. 4. Morphometrical changes after selective biliary ligation were reversible, whereas in liver lobes with selective portal ligation a progressive parenchymal destruction and involution with subsequent impairment of hepatic function of the concerned lobe was observed.