Small Intestinal Submuosa as a Bioscaffold for Biliary Tract Regeneration.
Abstracts
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Porcine small intestinal submucosa (SIS) is used as a bioscaffold for regeneration of a variety of tissues. To date, SIS has not been used as a biliary tract graft. The purpose of this study was to evaluate the feasibility of using SIS as a scaffold for bile duct tissue regeneration in a canine model. Twelve mongrel dogs weighing 25 kg each underwent midline laparotomy and exposure of the common bile duct. Nine dogs underwent longitudinal choledochotomy and placement of a 2x1 cm elliptical patch of SIS. Three dogs had the anterior two thirds of the common bile duct resected and a 2 to 3 cm SIS interposition graft placed. Neither T tubes nor external drains were used. Dogs were sacrificed at intervals ranging from 2 weeks to 5 months. Prior to sacrifice, liver function tests (Alkaline phosphatase(U/L), bilirubin (mg/dL)) were evaluated, cholangiograms were performed, and the bile duct was examined histologically. Eleven dogs survived and were healthy at the time of elective necropsy. The one failure was due to a technical suturing error resulting in a bile leak in a patched animal. The remaining eight SIS patch animals had normal liver function tests throughout the study period (mean Alk phos 61, total bilirubin 0.15). There were no strictures documented on cholangiogram. Microscopically, within two weeks the patch was covered with a biliary epithelium and had infiltration of native blood vessels. By 5 months, the patch was replaced with native collagen covered with a biliary epithelium. All three of the interposition grafts had normal liver function tests throughout the study period (mean Alk phos 26, total bilirubin 0.2). Cholangiograms demonstrated a normal caliber common bile duct throughout the interposition graft and no strictures occurred. Histologically, at three months the SIS interposition graft was identical to the native canine common bile duct. SIS results in regeneration of canine common bile duct when used as a patch or as an interposition graft. The potential for the use of SIS as a patch for biliary stricturoplasty, or as an interposition graft for repair of complex biliary injuries is encouraging. |
