Obstructive cholestasis is characterized clinically by jaundice, discolored urine, pale stools and pruritus1. The obstruction of the biliary tree, either intrahepatic or extrahepatic, causes a high rate of morbility and mortality in the human clinical field2. The serious repercussions of cholestasis on the liver and on the systemic level1,2 have led to the creation of many experimental surgical models so as to better understand its pathogenesis, prophylaxis, and treatment.
Comparison between macrosurgical and microsurgical extrahepatic cholestasis
Several surgical techniques for developing extrahepatic cholestasis have been described, especially in the rat. The techniques that are generally used to produce obstructive jaundice in the rat are macrosurgical, since they do not require magnification devices to be performed. The macrosurgical extrahepatic cholestasis called common bile duct ligation (BDL) is the most frequently used, and it consists of sectioning the common bile duct between ligatures3-5. This technique induces potential models of reversible obstructive jaundice, since they imply a high incidence of recanalization of the extrahepatic biliary route6, which can be avoided by placing the duodenum and the distal part of the stomach between the two ligated and sectioned ends of the bile duct6.
However, rats with macrosurgical extrahepatic cholestasis by BDL develop an infected hilar biliary pseudocyst by the progressive dilation of the proximal end of the bile duct6. At 16 days of postoperative evolution, the biliary culture of these pseudocysts is positive, the most frequent germs being Escherichia coli and enterococcus 7. Furthermore, the animals generally evolve with hepatic, intraperitoneal and pulmonary abscesses, and their elevated early mortality is attributed to sepsis8.
Microsurgery makes it possible to develop obstructive jaundice in the rat by the resection of the extrahepatic biliary tract that includes both the common bile duct as well as the bile ducts aimed at each of the four hepatic lobes8. With this technique, the non-existence of the residual proximal extrahepatic biliary tract prevents both the formation of hilar biliary pseudocysts as well as abdominal-thoracic abscesses, and prevents mortality during the evolution in relation to the bile duct-ligated model8,9.
To achieve reproducible results, a harmonization of the microsurgical technique for extrahepatic cholestasis in the rat is needed. Here, we describe a step-by-step surgical approach to resect the bile ducts that drain the four lobes of the liver in continuity with the common bile duct up to the beginning of its intrapancreatic segment by means of a microsurgical technique8-11.
This protocol is not associated with short-term mortality and has been used to produce data for several publications12