大鼠门静脉转流下耐受入肝血流阻断的安全时限

目的 评估在排除门静脉淤血条件下动物耐受入肝血硫阻断的安全时限。方法 利用大鼠肝脏及肝蒂分支分叶的解剖特点,阻断肝左、中和右叶肝蒂,以尾叶静脉系统作为阻断入肝血流期间门静脉血液的流出道,肝脏复流后切除尾叶。在这一模型上,以阻断入肝血流不同时程后动物7d存活率、肝脏病理组织学改变及肝脏能量代谢功能损害的严重度及可逆性来推断动物耐受常温下入肝血流阻断的安全时限。结果 门静脉转流下阻断入肝血流90min以内,术后7d动物全部存活,其肝脏缺血-再灌流损害以肝窦淤血和肝细胞变性等可逆性病变为主,而肝脏能量代谢功能损害可得以代偿和恢复。阻断入肝血流100、110、120min后动物7d存活率分别为50％、30％和20％,肝脏缺血120min后肝脏缺血-再灌流损害则以大量肝组织坏死为显著特性,其肝脏能量代谢功能严重受损而陷入失代偿状态。结论 大鼠在门静脉轻流时对常温下持续入肝血流阻断的耐受性显著增强,其安全时限是90min。

The tolerance limit of rats to normothermic hepatic inflow occlusion with portal blood bypass

Obective To evaluate the tolerance limit of rats to normthermic hepatic inflow occlusion with portal blood bypass. Methods A new animal medel of normthermic hepatic inflow occlusion with portal blood bypass was produced by clamping temporarily the pedicle of all liver lobes but that of caudate, which remained as a passage of the portal blood flow. To determine the safe tolerance limit of the rat to hepatic inflow occlusion the survival rates, hepatic mforphology and energy metabolism of the animals following temporary clamp of liver pedicle were investigated. Results All of the rats subjected to 30, 60 and 90 min of hepatic inflow occlusion with portal blood bypass survived on the seventh postoperative day. The ischemia - reperfusion injury of the liver was reversible and compensatory in rats with hepatic inflow occlusion within 90 min. However, the survival rates of rats with 100, 110 and 120 min of hepatic inflow occlusion were 50, 30 and 20 percent respectively, to correspondence with which the liver injury of rats with 120 min of hepatic inflow occlusion was severe and irreversible. Conclusions The tolerance of rats to normo-thermic hepatic inflow occlusion is enhanced significantly under portal blood bypass. The safe tolerance limit of rats to hepatic inflow occlusion with portal blood bypass is 90 minutes.