局部胆管内压大小及持续时间对犬胆管壁的影响

Influence of magnitude and endurance of local bile duct pressure on bile duct wall in dogs

目的探讨局部肌管内压大小及持续时间对犬胆管壁的影响。方法设计并自制一内置入式胆管扩张器,体外测试扩张气囊内压力与注水容积及囊径的关系。将20只杂交犬随机分为5组,A组为假手术组仅在胆总管内放置胆管扩张器;B、C组分别向扩张气囊内注水0.1 ml、0.2 ml(球囊压力分别为0.24 kPa、0.58 kPa)扩张胆总管,10 min后抽空气囊并留置胆管扩张器作胆汁引流;D、E组分别向扩张气囊内注水0.1 ml、0.2 ml扩张胆总管后,不抽空气囊并留置作胆汁引流。各组分别于术后7 d再次剖腹。观察各组扩张前后血清总胆红素(TB)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)值及胆管直径(BD)变化、胆管壁及肝组织学改变。结果与A组比较,C组扩张后BD增宽(P<0.05),D组扩张后BD显著增宽(P<0.01).E组扩张后TB、ALT、AST均增高(P<0.01);A、B组胆管壁组织学无明显变化,C组胆管壁黏膜充血水肿,部分黏膜脱落,D组胆管直径增粗及胆管壁增厚。E组胆管壁部分坏死,与网膜或十二指肠粘连。结论局部胆管内压大小及持续时间对犬胆管壁的影响存在双向互变关系,正常胆管壁在一定的时间内可承受一定的局部胆管内压而不致发生胆管壁的病理变化,适宜的局部胆管内压可引起局部胆管及其上游胆管壁扩张,反之,胆管壁可出现破坏性改变。

Objective To investigate the influence of magnitude and endurance of local bile duct pressure on bile duct wall in dogs. Methods An inlaid bile duct dilator （IBDD） was designed and made by us, and the relation of pressure to fusion volume and diameter of its expanded balloon was determined in vitro. Twenty-five mongrel dogs were randomized into 5 groups. Group A was the sham operated and IBDD was placed for biliary drainage in common bile duct. In group B and C, IBDD was placed in the common bile duct for biliary drainage to dilate it through adding 0. lml and 0.2ml water （the pressure of expanded balloon was 0.24 kPa and 0.58 kPa, respectively） for 10 min before evacuating the expanded balloon. In group D and E, IBDD was placed likewise except for not evacuating the balloon. The dogs in each group underwent laparotomy again 7 d after the first operation. The serum total bilirubin （TB）, ALT, AST, diameter of bile duct （BD）, histological changes of biliary tract wall and hepatic tissue were determined during biliary predilation and postdilation in all the 5 groups. Resuits As compared with group A, the BD of postdilation was expanded in group C （P〈0.05） and group D （P〈0.01）, TB, ALT and AST in the serum were highly increased in group E （P〈0.01）. There was no significant difference in histological changes of biliary tract wall between group A and group B. There was mucous hyperemia and hydropsy of biliary tract accompanied with partial mucous exfoliation in group C, increase of biliary tract diameter and thickening of biliary tract wall in group D and partial necrosis of biliary tract wall and adhesion to epiploon and duodenum in group E. Conclusion There is a two-way interconversion relationship between the influence of magnitude and endurance of biliary tract pressure and bile duct wall in dogs. Normal biliary tract wall can bear the pressure to some extent and no pathological change can be caused. Suitable pressure of biliary tract causes dilation of local bile duct and its upstream and downstream segments. On the contrary, unsuitable pressure will result in destructive changes in biliary tract.