[An experimental study on the pathophysiology of stenosis and occlusion in portal vein reconstruction in resection of cancer of the hepatic hilus].

An experimental study using mature mongrel dogs was performed to clarify the pathophysiology of stenosis and occlusion of portal vein reconstruction accompanied with hepatectomy. All the animals underwent partial (53%) hepatectomy. They were arbitrarily divided into three groups: Non-stenosis Group I with hepatectomy only, Stenosis Group II with partial '70%) stenosis of the portal vein, and Occlusion Group III with ligation of the portal vein. All cases of Group III died within about 122 minutes. The blood flow and pressure of the portal vein, portography, ICG Rmax and the residual liver weight were serially examined until the fourth week following the operation in Group I and Group II. Two principal results were derived: 1) In Group I, portal circulation was sufficiently restored and the residual liver showed adequate regeneration. 2) In Group II, hepatofugal collateral vessels developed. However, the portal pressure remained significantly high (p less than 0.002) and, the portal blood flow and liver tissue blood flow were markedly reduced (p less than 0.001) for 1 week after operation. The residual liver weight and liver function (ICG Rmax) were significantly decreased even in the fourth week. Recently, portal vein resection accompanied with hepatectomy has been accepted as a procedure for advanced carcinoma of the hepatic hilus. This study suggests that stenosis or occlusion of the portal vein should be avoided in the procedure.