肠腔分流条件下猪单纯门静脉阻断的安全时限

Tolerance of portal vein occlusion by meso-caval shunt in Bama swines

目的利用人工血管行肠系膜上静脉与肝下下腔静脉搭桥建立暂时性肠腔分流动物模型,初步摸索肠腔分流条件下猪单纯门静脉阻断的安全时限。方法将14头正常巴马小型猪分为A组(门静脉阻断120 min)、B组(门静脉阻断150 min),(n=7)。两组动物在全麻插管呼吸机辅助呼吸的条件下用人造血管在肠系膜上静脉、肝下下腔静脉间架桥,建立临时性肠腔分流模型,按分组阻断门静脉。对照观察两组动物在阻断前、复流前、复流后2h及术后1、3、5d的ALT、AST、TBIL及肝组织病理变化情况。结果①整个阻断门静脉的过程中,各组动物肠管未见明显淤血,颜色基本正常,证实采用人工血管在肠系膜上静脉与肝下下腔静脉间架桥行暂时性门腔分流有效。②A组动物长期存活率为100%,B组长期存活率为57.1%,两组动物存活率有显著差异(P<0.05)。③在复流前、复流2h、术后1 d各相同时相点,B组动物的ALT、AST、TBIL组较A组明显升高(P<0.05)。④A组门静脉阻断120min,汇管区炎细胞浸润;复流2 h后,病变进一步加重,肝细胞出现变性,灶性坏死,肝窦充血,汇管区及肝窦内明显炎细胞浸润。B组门静脉阻断150min肝见汇管区大量出血,白细胞聚集,细胞广泛空泡样变,肝组织灶性坏死;复流2 h后,进一步加重,肝细胞广泛气球样变、脂肪变性,内皮细胞肿胀、水肿明显,肝窦广泛充血,汇管区及肝窦大量炎性细胞浸润,B组较A组损伤更为显著,两组有显著性差异。电镜下B组较A组线粒体水肿,内质网扩张扩张更为明显,且出现细胞核高度浓缩,纤维沉积等不可逆损伤。结论在肠腔分流条件下,避免肠道淤血,正常巴马小型猪耐受单纯门静脉阻断安全时限为120min。

Objective To establish an animal model of hepatic inflow occlusion with meso-caval shunt in Bama swines and to evaluate the tolerance limit of portal vein occlusion. Methods Fourteen Bama swines were divided into group A and group B, and their portal vein blood inflow was blocked respectively for 120, 150 min. The animal survival rate, the changes of liver function and histopathology were observed before occlusion and reflow, and 2 h, 1, 3, 5 d after reflow. Results All through the portal vein occlusion process, the gut was of no significant congestion and in normal color, suggesting the temporary portacaval shunt is efficient. The animal survival rate of group A was significantly higher than that of group B （ 100% vs 57.1% , P 〈 0.05 ）. For groups A and B, a rise of their ALT, AST, TBIL values were observed, and those changes in group B were higher than those of group A. At 150 min after portal vein occlusion, great amount of hemorrhage, WBC aggre- gation, cell vacuolation and focal necrosis of hepatic tissues in portal area were observed in group B. Two hours after reflow, further deteriorated lesions occurred, such as fat degeneration, ballooning degeneration of hepatocyte, swelling endothelial cells, and congestion of sinus hepaticus under light microscope or electron microscope, less severe in group A than group B. Under electron microscope, mitochondrial edema and the expansion of endoplasmic reticulum of group B were more obvious, and additionally there were most concentrated nucleus, deposition of fibrous matrix, and other irreversible injury. Conclusion Two hours is the tolerance limit for the portal vein occlusion for Bama swine under the condition of meso-caval shunt.