Novo modelo experimental de obstrução biliar em ratos wistar




The purpose of this study was to create an obstruction in the biliary duct using a surgical procedure without ligatures, sectioning, or cannulation that would evolve to chronicity and develop into cirrhosis (or at least standard biliary fibrosis) and also to maintain an easily accessible extra-hepatic biliary route .The histopathologic assessment of the liver and the biochemical effects on the serum were conducted 30 days after obstruction. This study was conducted on 63 Wistar rats, which were divided into 3 groups: 47 animals underwent a common obstruction of the hepatic duct (OB), 9 underwent a simulated surgery (OS) and 7 were used as the control group for histologic analysis (OC). The surgical technique used isolated the hepatic duct as it emerged near the pancreas with polypropylene thread, leaving 1cm of the duct free. The xiphoid appendix was then exposed and using the rat s ear marker a small orifice was made in it. The polypropylene thread attached to the biliary duct was then drawn through this orifice forming a biliary duct sling above the xiphoid appendix and a silicon catheter was then placed in it. It therefore remained stretched and exposed between the musculature and skin . The muscle wall and skin were closed with continuous sutures. The total number of rats in the OB group diminished by fifteen (32%): 8 rats suffered an early death and 7 rats died as a result of a technical error (in 4 cases, the catheter was not correctly placed and in 3 cases, the bile duct ruptured). The remaining 32 rats in the OB group when compared to those in the OS group presented a significant increase in the dosage of bilirubin, aminotransferases (ALT &AST), alkaline phosphatase and gammaglutami] transferase with a reduction in albumin The histologic analysis confirmed the development of "standard biliary fibrosis" in all the OB group cases and the formation of regenerative nodules in 68.7% of the group. "Standard biliary fibrosis" was characterized by portal fibrosis (slight to moderate) in 96.8% of the cases with the formation of fibrous septa (moderate to intense ) in 87.4% of the cases, together with an intense proliferation of the biliary ducts in 81.2% of the cases and in 18.7% the proliferation was moderate. An alternate experimental model that was simple and efficient was developed and as it was easy to manipulate the obstruction provoked by traction of the biliary duct, excellent research conditions were provided right from the moment the biliary flux was interrupted up to the development of cholestase and the distortion of the hepatic structure. This model also permits an interruption of the biliary obstruction and a study of the sequels caused by obstructive icterus


figado cirrose hepatica trato biliar - cirurgia ictericia

Documentos Relacionados