Hepatobiliary Physiological Changes After Roux-en-Y Cholecysto-colonic Diversion

BackgroundThe non-transplanting treatment for progressive familial intrahepatic cholestasis (PFIC) patients included partial external biliary diversion (PEBD) and partial internal biliary drainage (PIBD). PEBD was not readily accepted by all the patients and the families because of the permanent abdominal stoma. A stoma-free partial internal biliary drainage (PIBD) was a complex operation and diarrhea inducing by bile was difficult to treat. Small bowel resection must be carried out. To solve these problems, we have developed a novel approach, Roux-en-Y cholecystocolonic bypass, which partially diverts bile into colon directly without a jejunal conduit. Understanding about its impact on hepatobiliary physiology after this novel operation is limited.PFIC was a rare autosomal recessive cholestatic disease with estimated incidence between1/50000and1/100000. Although three types of PFIC had been identified, early diagnosis was still difficult. When diagnosis of PFIC was confirmed, some patients had already progressed to liver fibrosis or cirrhosis. It was difficult to conduct large scale clinical trials or controlled studies. To ensure consistency in the research subjects, an animal model seemed to be the best choice for investigating the effects of cholecystocolonic bypass on hepatobiliary system.ObjectiveThe aim of the present study is to investigate, using a rabbit model, the changes in bile flow, total bile acid (TBA) level, bacterial and histological changes induced by Roux-en-Y cholecystocolonic anastomosis. Methods24rabbits, randomize divided into3groups:(1)normal control group (n=8),(2) PIBD group (n=8).(3) Roux-en-Y cholecysto-colonic anastomosis group(n=8).1year postoperation, dynamic biligraphy was performed to evaluate the reliability of this animal model. Pre-and post-opertive bile and blood were acquired to examine the change of TBA level. Tissues from the live, gallbladder and colon were also obtained to have pathological test. Bacterial changes also test postperatively. Moreover, another24rabbits were divided into3groups:(1) normal control (n=8),(2)30cm long limb group (n=8) and (3)10cm short limb group (n=8). Group2or3underwent Roux-en-Y cholecysto-colonic anastomosis with a30or10cm length Roux limb, and group1underwent sham operation. One month later, quantitative hepatobiliary scintigraphy was performed to detect the parameters of biliary dynamics using regions of interest (ROI) technology.ResultsAll animals survived and developed normally during follow-up period. Biligraphy showed that bile was diverted into colon directly after cholecystocolonic anastomosis. Thus, the animal model was successful. TBA level in bile decreased73%from (801.46±22.54)μmol/L to (214.08±12.24)μmol/L. TBA level in portal vein was also decreased78%from (85.33±2.08)μmol/L to (18.85±2.01)μmol/L. After1year, examination of intestinal content showed a significantly decreased number of coliform in the Roux-en-Y cholecysto-colonic group as compared with native control animals. The total positive rate by bacterial culture was12.5%(4/32) and9.375%(3/32) respectively. No difference in the incidence was found among the two groups. E. coli was the most common bacterial cultured. No obvious pathologieal damage to the rabbit’s liver, gallbladder and colon after cholecysto-colonic anastomosis was found. Hepatobiliary scintigraphy showed that E20and E35values were (77.27±6.15)%and (90.39±1.49)%respectively in short limb group. That is to say, gallbladder emptying in10cm long limb group was more rapidly than the other two groups. Moreover, the ratio of bile shunt was (0.547±0.182), which was also more than the ratio in the long limb group (P<0.05). The activity-time curve for the GB in the long limb group was like wave. ConclusionsIt is feasible and safe to hepatobiliary system after Roux-en-Y cholecysto-colonic anastomosis. Bile bypassed into colon directly, and TBA level in the body was decreased obviously. Roux-en-Y cholecysto-colonic anastomosis itself could not increase the incidence of bacterial translocation, postoperative infections, colorectal cancer induction. Scintigraphy99mTc-EH1DA to assess the ratio of bile diversion, gallbladder motility and overall liver function is a method with satisfactory reproducibility. The effect of bile diversion in10cm short limb rabbit model group is better than the30cm long limb group.