Xu G, Elsey R M, Lance V A, Javors B, Chen T S, Salen G, Tint G S
VA Medical Center, East Orange, New Jersey 07018, USA.
J Exp Zool. 1997 Dec 15;279(6):554-61.
The anomalous arrangement of bile ducts in the Crocodylia has not been fully appreciated. A clear understanding of biliary anatomy is necessary in order to create complete bile drainage in these reptiles. The object of this study was to clarify the anatomy of the bile ductal system and to establish total bile fistulas in the American alligator, Alligator mississippiensis. Bile duct anatomy was studied in 104 juvenile alligators, and bile fistulas were constructed in seven alligators. In 93 out of 104 (89%) of the juveniles dissected there was an interconnection between the right and left hepatic duct before the right hepatic duct emptied into the gallbladder. The left hepatic duct then entered the duodenum independently of the cystic duct which drained the gallbladder directly into the duodenum. In 8% of the animals, the left hepatic duct did not enter the duodenum but joined with the right duct, forming a common hepatic duct that emptied into the gallbladder. In 3% of the cases, the right hepatic duct emptied into the gallbladder, while the left duct had no communication with the right hepatic duct and drained separately into the duodenum. This arrangement of bile ducts is similar to that seen in birds and reflects the common ancestry of crocodiles and birds. In other reptiles, the biliary system shows much more variability and is different from the alligator. In five of seven alligators in which total biliary diversion was attempted, the biliary catheter remained in place and stayed patent from 2-7 weeks. Bile flow was extremely low (1.5-2.5 ml/24 h) when compared to that of mammals (80-100 ml/24 h). This study demonstrates the variable nature of the biliary ductal system in Alligator mississippiensis and suggest a method for constructing an effective total bile fistula in these animals.
鳄鱼目动物胆管的异常排列尚未得到充分认识。为了在这些爬行动物中实现完整的胆汁引流，清楚了解胆管解剖结构是必要的。本研究的目的是阐明胆管系统的解剖结构，并在美国短吻鳄（密西西比鳄）中建立完全性胆汁瘘。对104只幼年短吻鳄的胆管解剖结构进行了研究，并在7只短吻鳄中构建了胆汁瘘。在解剖的104只幼年短吻鳄中，有93只（89%）在右肝管汇入胆囊之前，左右肝管之间存在相互连接。然后左肝管独立进入十二指肠，而胆囊管则直接将胆囊引流至十二指肠。在8%的动物中，左肝管未进入十二指肠，而是与右肝管汇合，形成一条汇入胆囊的肝总管。在3%的病例中，右肝管汇入胆囊，而左肝管与右肝管无连通，单独引流至十二指肠。这种胆管排列方式与鸟类相似，反映了鳄鱼和鸟类的共同祖先。在其他爬行动物中，胆管系统表现出更大的变异性，与短吻鳄不同。在尝试进行完全性胆汁转流的7只短吻鳄中，有5只的胆管导管保持在位且在2 - 7周内保持通畅。与哺乳动物（80 - 100 ml/24 h）相比，胆汁流量极低（1.5 - 2.5 ml/24 h）。本研究证明了密西西比鳄胆管系统的可变性质，并提出了一种在这些动物中构建有效完全性胆汁瘘的方法。
