Effect of bypass flow rate of portosystemic bypass on the visceral organs in acute portal vein occlusion

本研究的目的是确定急性门静脉阻塞(PVO)时使用肝素涂层导管Anthone进行门体分流的临界流量(BFR)。麻醉犬各实验组BfR分别控制在门静脉血流量的10%(第1组)、30%(第2组)、50%(第3组)。随着BFR的降低，门静脉压力升高，第1组为47.1 mm Hg，第2组为26.8 mm Hg，肠系膜上动脉血流量在第1组和第2组均显著降低，而第3组P&lt；SMA&gt；变化不大，呈负相关(r=-0.911，P&lt；0.0001)，并分别与F&lt、SMA、Gt；呈正相关(r=0.875，P&lt；0.0001)。门静脉血红细胞压积下降，门静脉血红细胞压积升高，第1组为54.5%，第2组为50.3%。术后2小时门静脉血pH值下降，第1组为7.210，第2组为7.337。门静脉血CPK-BB水平与肠损伤程度密切相关。结论：门静脉血流的临界BFR应在门静脉血流量的10%~30%之间，才能维持门静脉血流至2小时，而50%的BFR足以维持肠系膜器官绝缘。

The object of this study was to determine the critical flow rate (BFR) of the portosystemic bypass, using heparin coated catheter Anthrone, during acute portal vein occlusion (PVO). BFR was controlled at 10% (Group 1) , 30% (Group 2), 50% (Group 3) of the portal flow in the individual experimental groups of anesthetized dogs. Hemodynamic and biochemical changes were observed during 2 hours in each group.With decreased BFR, portal venous pressure (P_<pv>) increased, with 47.1 mmHg in Group 1 and 26.8 mmHg in Group 2, and superior mesenteric arterial flow (F_<sma>) decreased remarkably in both Group 1 and Group 2. However, P_<sma> showed negligible changes in Group 3. Thus, negative correlation between BFR and P_<pv> (r=-0.911, P<0.0001), and positive correlation between BFR and F_<sma> (r=0.875, P<0.0001) were found respectively. With decreased BFR, portal venous blood hematocrit increased, with 54.5% in Group 1 and 50.3% in Group 2. Following 2 hours PVO, pH levels of portal venous blood were reduced, with 7.210 in Group 1 and 7.337 in Group 2. CPK-BB levels of portal venous blood correlated well to the degree of intestinal insultation.In conclusions, the critical BFR must be between 10% and 30% of portal flow for life sustaining up to 2 hours PVO, and 50% BFR is sufficient enough in more than 2 hours PVO, in the aspect of mesenteric organ insultation.