Endoscopic-assisted laser sphincterotomy of the intramural common bile duct: A cadaveric pilot study.

Objective: To (1) develop a minimally invasive technique for endoscopic-assisted retrograde catheterization (EARC) of the major duodenal papilla (MDP) in dogs and (2) pilot a safe method of endoscope-guided laser sphincterotomy of the intramural segment of the common bile duct (ICBD).

Study design: Descriptive study.

Animals: Twenty fresh canine cadavers.

Methods: Following mini-midline celiotomy and exteriorization of the distal duodenum, endoscopy of the duodenal lumen was performed under saline irrigation via a 5 mm cuffed endoscopic port using a 2.7 mm 30° rigid cystoscope and HoYag laser fiber. Endoscopic-assisted retrograde catheterization of the MDP and laser sphincterotomy extended to the end of the ICBD was performed. The duodenal segment was dissected under magnification following the endoscopic procedure. The length of the ICBD and the incidence of iatrogenic injury were recorded.

Results: The EARC of the MDP and laser sphincterotomy were successful in 18 of 18 attempts. The ICBD segments ranged from 10 to 21 mm long (n = 20) (body weight 6.6-37.0 kg). There was no correlation between body weight and length of the ICBD (Pearson's rho = .06, p = .79). Partial thickness lateral perforations occurred in two specimens. Division of the submucosal layer during ablation heralded the start of the extramural segment and could be identified consistently (16/18; 88%).

Conclusion: Endoscopic-assisted retrograde catheterization and extended laser sphincterotomy appeared feasible and safe in canine cadavers. Further evaluation in a live-animal setting is warranted.

Clinical significance: Endoscopic-assisted retrograde catheterization may have advantages over current open techniques for accessing the duodenal papilla and endoscopic laser sphincterotomy may assist resolution of ICBD obstructions.