Minimally invasive bile duct stenting for dogs with bile duct blockage

Abstract

OBJECTIVE: To describe techniques for endoscopic retrograde cholangiography (ERC) and endoscopic retrograde biliary stenting of the common bile duct (CBD) for minimally invasive treatment of extrahepatic bile duct obstruction (EHBDO) in dogs. DESIGN: Experimental study and clinical report. ANIMALS: 7 healthy research dogs and 2 canine patients. PROCEDURES: ERC and endoscopic retrograde biliary stenting were performed in healthy purpose-bred research dogs and client-owned dogs with a diagnosis of EHBDO that underwent an attempted biliary stent procedure. Research dogs were euthanized after completion of the procedure and underwent necropsy. With dogs under general anesthesia, the pylorus was cannulated with a side-view duodenoscope, and the duodenum was entered. The major duodenal papilla (MDP) and minor duodenal papilla were then identified, and the MDP was cannulated. Endoscopic retrograde cholangiography and endoscopic retrograde biliary stenting were attempted with the aid of endoscopy and fluoroscopy in all dogs. Procedure time, outcome for duodenal and MDP cannulation, and success of stent placement were recorded. RESULTS: Endoscopic retrograde cholangiography was successfully performed in 5 of 7 research dogs and in 1 of 2 patients. Biliary stenting was achieved in 4 of 7 research dogs and 1 of 2 patients, with a polyurethane (n = 4) or self-expanding metallic stent (1). One patient had a mass such that visualization of the MDP was impossible and no attempt at biliary cannulation could be made. After placement, stent patency was documented by means of contrast cholangiography and visualization of biliary drainage into the duodenum intra-operatively. No major complications occurred during or after the procedure in any patient. Follow-up information 685 days after stent placement in 1 patient provided evidence of biliary patency on serial repeated ultrasonography and no evidence of complications. CONCLUSIONS and CLINICAL RELEVANCE: ERC and endoscopic retrograde biliary stenting were successfully performed in a small group of healthy dogs and 1 patient with EHBDO, but were technically challenging procedures. Further investigation of this minimally invasive technique for the treatment of EHBDO in dogs is necessary before this may be considered a viable alternative to current treatment methods.