Objective To investigate the application value of Bama miniature pig model in endoscopic retrograde cholangiopancreatography (ERCP) training.

Methods The experimental study was conducted. Six Bama miniature pigs were selected to establish animal model for ERCP operation. The experimental equipments were the EP‑6000 image processing system and ED‑580T therapeutic duodenoscopy, and the surgery was performed by two experienced chief physicians. Observation indicators: (1) surgical operation status; (2) preoperative and postoperative physiological and biochemical indicators of experimental animals; (3) experimental endpoint indicators. Measurement data with normal distribution were represented as Mean±SD, and measurement data with skewed distribution were represented as M(range). Count data were expressed as absolute numbers.

Results (1) Surgical operation status. During the operation, the time required for the duodenoscope to pass from the esophageal inlet to the pylorus of the six experimental animals was 151(range, 46-227)seconds, the insertion length of the endoscope at the pylorus was 85(range, 80-90)cm, and the straightened length of the endoscope shaft was 47(range, 45-50)cm. For bile duct cannulation, the total number of cannulation attempts was 2.0(range, 1.0-3.0), the number of successful cannulation was 1.5(range, 1.0-2.0), and the time of successful cannulation was 44(range, 13-80)seconds. For pancreatic duct cannulation, the total number of cannulation attempts was 3.0(range, 1.0-8.0), and only one successful intubation was performed for each experimental animal, with the time of successful cannulation as 100(range, 53-320)seconds. (2) Preoperative and postoperative physiological and biochemical indicators of experimental animals. For six experimental animals, the preoperative body temperature was (38.8±0.1)℃, serum amylase was (55.3±0.2)U/dL, serum lipase was 232.9(range, 29.4-547.3)U/L, alanine aminotransferase was (51±10)U/L, aspartate aminotransferase was (38±12)U/L, and total bilirubin was (3.2±0.7)μmol/L. At 24 hours postoperatively, the body temperature was (38.6±0.1)℃, serum amylase was (53.0±6.0)U/dL, serum lipase was 62.4(range, 29.4-94.1)U/L, alanine amino-transferase was (54±5)U/L, aspartate aminotransferase was (67±27)U/L, and total bilirubin was (3.5±1.9)μmol/L. (3) Experimental endpoint indicators. At the experimental endpoint of 14 days after surgery, the bile duct length in the six experimental animals was (8.6±1.2)cm, and the bile duct inner diameter was (2.5±0.5)mm. The pancreatic duct length was 12.9(range, 3.7-20.8)cm, and the inner diameter was (1.6±0.2)mm. Results of histopathological examination revealed that both CD3 and CD68 staining were negative in the bile duct and surrounding hepatic tissue, as well as in the pancreatic duct and adjacent pancreatic tissue at the experimental endpoint of 14 days after surgery.

Conclusion Bama miniature pig model can be used for ERCP training.