Choledocho-choledochostomy: the natural history of healing in pigs.

Background/purpose: Aiming to investigate the natural history of the healing of choledocho-choledochostomies.

Methods: Fifty-five female pigs of 57 kg median weight were used for the experiments. The gallbladder was removed and the common bile duct transected. Continuity was re-established by standardized single-line, interrupted, and inverted sutures. The pigs had a planned postoperative survival of up to 14 days with a subsequent laparotomy for evaluation. Blood samples were drawn prior to the first and the final operations. During laparotomy the animals were investigated for signs of cholascos, and an intraoperative cholangiography was performed. The excised anastomosis was examined for breaking strength and collagen content.

Results: Standard liver parameters were not significantly affected by the surgery, and cholangiography showed no signs of extrahepatic stenosis or intrahepatic dilatation. Breaking strength showed a decrease for the initial 3 postoperative days (PODs), then an increase to a stable level on PODs 6 to 14. Collagen content per volume showed a rise on PODs 0 to 1, then no change until POD 4, followed by a gradual rise until day 6. Subsequently a stable level was reached until POD 14. Two pigs were excluded due to minor cholascos.

Conclusions: The present study on pigs shows that choledocho-choledochostomies, judged by breaking strength and collagen content, regain a stable level of strength 6 days after operation.