A preliminary study of sphincter-preserving effect of SureClip from MicroTech on duodenal papilla occlusion

Objective To reduce the occurrence of recurrent choledocholithiasis caused by biliary sphincter dysfunction after extensive endoscopic sphincterotomy (EST) for large stone extraction, and to investigate the sphincter-preserving effects of duodenal occlusion by SureClip from MicroTech. Methods Three patients with large biliary stones (1.0-2.5 cm in stone size, 1.2-3.0 cm in common bile duct diameter) and without ERCP history underwent EST (larger than 1.0 cm) in Peking University Third Hospital from March 2018 to May 2018. Biliary and pancreatic stents were placed after stone extraction, followed by duodenal occlusion with SureClip from MicroTech. Pressures of biliary duct and Oddi sphincter were measured at pre-EST, immediately after EST, and when stents were removed 3 weeks after EST, respectively. Healing conditions of and complications were documented. Five pigs underwent similar experiments without stone extraction. Results The pressure of Oddi sphincter was significantly reduced after EST, and recovered after occlusion 3 weeks after operation both in pigs and human. All stones were completely removed in the 3 patients without any post-ERCP complications. The was healed under endoscopic observation when stents were removed 3 weeks after occlusion. In animal experiments, histology revealed completely muscularis propria disruption of post-EST without occlusion. In contrast, the muscle layer of post-EST with occlusion by SureClip from MicroTech appeared scar healing. Conclusion The duodenal occlusion by SureClip from MicroTech after EST works as papilla remolding , which accelerates healing of papilla, and retains the sphincter pressure and anti-reflux barrier function. Key words: Sphincter of Oddi; Sphincterotomy, endoscopic; Recovery of function; Animal experimentation