胃去门静脉循环断流术犬模型的建立

                       作者：赵磊 周岩冰 李世宽 吕亮 李宇 王亮 于冠君

【摘要】  目的 设计胃去门静脉循环断流术的方法，并建立胃去门静脉循环断流术犬模型。方法 应用缩窄门静脉主干1/2加丝线慢性栓塞术制作犬肝前型门静脉高压食管静脉曲张模型。然后，实施胃去门静脉循环断流术，即行脾切除后，保留贲门周围血管、食管曲张静脉及迷走神经，从根部离断胃冠状静脉等汇入门静脉系统的胃静脉血管，使胃的静脉血流经门奇间的交通支血管进入体循环。将已形成肝前型门静脉高压食管静脉曲张犬12只随机分为脾切除组、贲门周围血管离断术组、胃去门静脉循环断流术组。于开腹后、手术后即刻及术后3周末测量门静脉及食管曲张静脉压力。术前及术后3周末测定肝功能指标。结果 犬模型均存活。手术后即刻及术后3周末与开腹后相比，胃去门静脉循环断流术组门静脉压力显著下降(F=7.386，q=3.503、3.121，P<0.05);食管曲张静脉压力亦显著下降(F=8.026，q=3.661、3.240，P<0.05)。手术前后肝功能指标变化不明显(t=0.268～1.325，P>0.05)。结论 胃去门静脉循环断流术犬模型存活率高，制作方法简单易行，模型质量可靠，有助于研究胃去门静脉循环断流术对门静脉血流动力学参数的影响。 
【关键词】  高血压,门静脉;模型,动物;狗
[ABSTRACT] Objective To design a method of de?portal?circulation disconnection (DPCD) of stomach and create a model of DPCD of stomach in dog. Methods A model of prehepatic portal hypertension with esophageal varices (VE) was created in dog through narrowing main portal vein by plus suture silk to establish chronic embolism. Disconnection of DPCD was then performed, i.e. splenectomy with preserving peripheral vessels of the cardia, varicose veins of the esophagus and vagus nerve. The vena coronaria ventriculi and others that abouchement in portal system were mutilated at their base, resulting in blood stream of the stomach flowed into general circulation through the communicating branches. The 12 dog models created were randomized to three groups as group A (splenectomy),group B (mutilation of blood vessel surrounding the cardia), and group C (DPCD of the stomach). The portal vein pressure (PVP) and varicose vein pressure (VVP) was measured at opening of the abdomen, immediately after surgery, and three weeks postoperatively. Liver function tests were conducted before and three weeks after surgery. Results All the model dogs survived. Compared with immediately after surgery and three weeks later to at opening of the abdomen, the PVP and VVP decreased significantly after DPCD (F=7.386;q=3.503,3.121;P<0.05) and (F=8.026;q=3.661,3.240;P<0.05), respectively. As for liver function, no obvious changes were recorded between before and after surgery (t=0.268-1.325,P>0.05). Conclusion The survival rate of model dogs of DPCD is high, its procedure is simple, and quality is reliable, this method is conducive to the research of the effect of DPCD on hemodynamics of portal vein.
　　[KEY WORDS] hypertension, portal; model, animal; dogs
　　贲门周围血管离断术阻断门奇静脉间的异常血流可起到治疗食管曲张静脉破裂的作用[1]，但手术后胃的静脉血仍然经过门静脉属支回流到压力升高的门静脉系统，使门静脉高压性胃病(PHG)的发生率明显增加[2]。为此，我们设计这样一种手术方式：保留贲门周围血管及食管曲张静脉，离断包括胃冠状静脉等汇入门静脉系统的胃血管，使胃的静脉血流完全摆脱门静脉系统，经门奇间的交通支血管进入体循环，即“胃去门静脉循环”，使食管曲张静脉的压力下降至不足以破裂的程度，达到控制食管曲张静脉破裂出血及减轻PHG的目的。本研究通过建立犬肝前型门静脉高压食管静脉曲张模型，然后实施上述手术，制作胃去门静脉循环断流术犬模型。现报告如下。
　　1 材料与方法
　　1.1 实验动物
　　健康成年Beagle犬12只，雌雄不限，其中雄性5只，雌性7只。体质量为(8.5～11.4)kg,平均(9.83±0.88)kg。实验前所有动物谷丙转氨酶(ALT)、清蛋白(ALB)、球蛋白(G)均正常。
　　1.2 模型制作
　　所有动物均采用缩窄门静脉主干1/2加丝线慢性栓塞术[3]建立犬肝前型门静脉高压食管静脉曲张模型。术前晚禁食。采用10 g/L丙泊酚1 mL/kg体质量静脉麻醉，上腹正中切口进腹。常规探查腹腔内肝、脾、胃、小肠等有无病变。于肠系膜上静脉穿刺测压。游离出门静脉主干, 用血管钳暂时阻断门静脉主干，采用“插管 (管内事先装有10号丝线1根)水冲法”分别于门静脉左右两支各放置长度为12～16 cm及9～12 cm的丝线1根。放线同时，缓慢退出插管, 用4?0血管线缝合门静脉破口, 并与丝线末端打结固定。然后，用血管钳由前向后夹扁预定要缩窄处的门静脉主干, 再用4?0血管线于钳子上方紧贴钳子从门静脉中点处缝过, 最后在门静脉前方打结完成缩窄50%的目标。术后常规饲养动物3周。
　　将已形成肝前型门静脉高压食管静脉曲张的犬12只随机分为3组, 即脾切除组、贲门周围血管离断术组、胃去门静脉循环断流术组，每组4只。胃去门静脉循环断流术组实施胃去门静脉循环断流术(图1)，即脾切除后，沿左右胃网膜血管交界向下切断胃大弯侧血管，将胃向右上翻起，在胃胰皱襞结扎切断胃后静脉，沿胃小弯切断胃冠状静脉的属支，并在根部切断胃冠状静脉。保留胃网膜右动脉和胃左动脉主干，保留胃小弯向上组织和血管、贲门周围血管、食管曲张静脉、左膈下血管及迷走神经主干;贲门周围血管离断术组行脾切除加贲门周围血管离断术;脾切除组仅行脾切除术。
　　图1 胃去门静脉循环断流术示意图
　　1.3 观察指标
　　术后观察犬的一般情况、营养状况、并发症等;分别于开腹后、手术后即刻及术后3周末穿刺肠系膜上静脉和贲门周围曲张静脉测定门静脉及食管曲张静脉压力;术前及术后3周末空腹时采集外周血，检查ALT、ALB、G等肝功能指标。