A new minimally invasive porcine model for the study of intrahepatic bile duct dilatation

Background Endoscopic ultrasound (EUS) procedures are becoming more frequent nowadays and novel techniques are on the rise. These procedures require high technical experience and complex endoscopic skills. The goal of this study was to develop a new minimally invasive animal model of bile duct dilatation in the pig, in order to offer a new tool for endoscopic and surgical therapy training and to test new therapeutic strategies. Methods Twenty-five female pigs underwent laparoscopic surgery in order to perform a common hepatic duct ligation. A pre- and postoperative biochemical analyses were performed: glucose, albumin, total bilirubin (TBil), gamma glutamyl transferase (GGT), alkaline phosphatase, and alanine aminotransferase were measured. Surgical time and intra- and postoperative complications were registered. Five to six days after surgery, an EUS was performed to measure intrahepatic duct size (mm). Distance from the bile duct to the EUS transductor was also recorded (mm).T-student for quantitative variables was applied. Statistical significance was defined aspvalue <= 0.05. Results The mean surgical time was 29.5 +/- 14.9 min. In five pigs (20%), some mild intraoperative problems occurred. A severe postoperative complication occurred in one animal (4%). No postoperative mortality was registered. Postoperative serum analyses showed an increase in total bilirubin (p = 0.005) and gamma glutamyl transferase levels (p = 0.001). Postoperative EUS showed dilatation of the intrahepatic bile duct in 76% of pigs, with a mean diameter of 9.6 +/- 3.6 mm (distance from the gastric wall of 17.0 +/- 6.4 mm). Conclusion The surgical procedure described here is a safe technique to induce dilatation of the intrahepatic bile ducts in the pig, with a minimally invasive approach and a high efficacy rate. This animal model might be useful for EUS techniques training and for evaluating new therapeutic approaches.

Automated summary

A new minimally invasive animal model of bile duct dilatation in pigs was developed through laparoscopic surgery. Postoperative analyses showed an increase in total bilirubin and gamma glutamyl transferase levels, with a majority of pigs showing dilation of the intrahepatic bile ducts. This animal model could be useful for training in EUS techniques and evaluating new therapeutic approaches.