[Experimental portal hypertensive colopathy in rats with liver cirrhosis]

To elucidate the morphological feature of portal hypertensive colopathy (PHC), the macroscopic and microscopic vascular alterations of colonic mucosa was observed in rats with thioacetamide-induced liver cirrhosis. The colored latex was injected into the portal vein and filled the peripheral veins on the colonic mucosa. Histologic study revealed an increased in the number of the cross sections of venous vessels containing the colored lactices in the lamina propria mucosa(LP), lamina submucosal(SM) and muscularis propria(MP) in the cirrhotic rats. Stereoscopic results of the vascular cast obtained from the cirrhotic rats showed the presence of two characteristic vascular sings, i.e., winding and tree like dilated vessels (WT) and vascular ectasia (VE). WT was characterized by tortuosity, dilatation and increase of the venous vessels in the LP, SM and MP, and VE was vascular spider-like lesion mainly in the LP or a clump of tortuous vessels in LP, SM and MP. In the clinical study, 38 patients with liver cirrhosis and 40 normal control received colonoscopic examinations. The vascular lesions similar to WT and VE were seen in 78.9% and 65.8% of cirrhotic patients, compared to 10.0% and 7.5% in the control. The differences were statistically significant indicated that WT and VE were thought to be the typical experimental models of PHC. Since the cirrhotic rats used the present study were administered thioacetamide for only 12 weeks, it was suggested that PHC could occurred even in early stage of liver cirrhosis with mild portal hypertension. Neither WT nor VE were associated with the Child-Pugh's grade of cirrhosis.