Abstracts
2000 Digestive Disease Week

# 2221 A Comparison of Common Bile Duct Pressures Following Botulinum Toxin Injection into the Sphincter of Oddi Versus Biliary Stenting in a Canine Model.
Jeffrey M. Marks, Andrew L. Bower, Marlene Goormastic, Janis L. Malycky, Jeffrey L. Ponsky, Cleveland, OH, Mayfield Height, OH

Introduction: Botulinum toxin A (Botox) functionally paralyzes the sphinter of Oddi (SO) in both humans and animals resulting in reduced SO pressures. No study, however, has specifically addressed common bile duct (CBD) pressures following Botox injection into the SO. The goals of this present study are to compare, versus biliary stenting, the change in CBD pressures following Botox injection into the SO, as well as to evaluate the timing of onset and duration of these effects on sphincteric relaxation with regards to treating biliary leaks and fistulae. Materials and Methods: Following midline laparotomy in twenty mongrel dogs, a pediatric umbilical catheter was inserted into the CBD via a small cholecystotomy and attached to a water-perfused pressure transducer. After baseline CBD pressure readings, a lateral duodenotomy was performed and the ampulla of Vater identified. A total of 100 units of Botox was injected with an endoscopic sclerotherapy needle in all four quadrants of the ampulla. The duodenotomy was closed and the cholecystotomy site repaired after removal of the pressure-sensing catheter. The dogs were randomly divided into four groups to undergo repeat laparotomy at either postoperative day (POD) 1 (Group I), POD 3 (Group II), POD 7 (Group III), or POD 14 (Group IV). At the time of second laparotomy, a pressure-sensing catheter was reinserted into the CBD and pressures recorded. Each dog then underwent transpapillary biliary stenting with a 7 Fr. x 5cm Cotton- Leung biliary stent and CBD pressures were recorded. Results: CBD pressures were signficantly lower as compared to baseline for all groups following Botox injection and biliary stenting (p<0.001). In addition, no significant differences in the degree of CBD pressure reduction were identified between groups I through IV following Botox injection. The measured decrease in CBD pressure from baseline following Botox injection as compared to biliary stenting was significantly different for groups I and II (p<0.05) but not for groups III and IV. Conclusion: Botox injection into the sphincter of Oddi results in significant CBD pressure reduction within 24 hours and continues for fourteen days. Also, after POD three, there is no significant difference in the reduction of CBD pressure from baseline between botox injection and biliary stenting. Based on these findings, Botox injection into the SO may be a beneficial alternative to biliary stenting for the treatment of biliary leaks and fistulae.