[Experimental study of the effect of portal vein occlusion on the mesenteric microcirculation]

The effect of portal vein occlusion (PVO) on the mesenteric microcirculation was studied with light microscope and electronmicroscope in the following three groups of mongrel dogs; the first group consisted of 3 dogs with laparotomy only, the second consisted of 10 dogs with PVO and the third consisted of 10 dogs with PVO and porto-femoral vein bypass using the antithrombogenic catheter (Anthron bypass tube). In the second group, dilatation of venula and slow blood flow in venula, patent A-V shunt and stasis in the capillary network were seen after 15 minutes. Hemorrhage and stasis in venula were observed after 15-30 minutes. Sludging and stasis in arteriole were also observed after 45-60 minutes. The hemorrhage of venula was progressive. Electronmicroscopically the vascular endothelial cell began to show abnormality after 15-30 minutes, and the microvilli of small intestinal mucosa showed pathological changes after 30 minutes. In the third group, the disturbance of the mesenteric microcirculation was mild even 4 hours after PVO. Both vascular endothelial cell and microbilli of the small intestinal mucosa were not damaged. We concluded that PVO causes the pathological changes of mesenteric microcirculation and intestinal mucosa at an early stage and the porto-femoral vein bypass using the antithrombogenic catheter is a safe and useful procedure when PVO is needed.