Aim: To evaluate the technical feasibility, safety, and short-term efficacy of botulinum toxin injection for pancreatic sphincter of Oddi dysfunction and to analyse whether the symptomatic response to botulinum toxin might be a predictor of outcome for endoscopic sphincterotomy.
Methods: Fifteen consecutive patients (nine female, aged 38 +/- 12 years) with frequent attacks (median four) of acute pancreatitis within 6 months, and manometrically proven pancreatic sphincter of Oddi dysfunction underwent endoscopic injection of 100 units of botulinum toxin into the major papilla. All patients underwent prospective follow-up thereafter and in cases of recurrent pancreatitis manometry this was repeated and pancreatic sphincterotomy was performed.
Results: No side-effects occurred after botulinum toxin injection in any patient. Within 3 months after botulinum toxin treatment, 12 out of 15 patients remained asymptomatic (80% primary response). Only one out of three patients without symptomatic benefit showed continued elevated pancreatic sphincter pressure at manometry and only this patient benefited from pancreatic sphincterotomy later on. Eleven of the 12 patients initially responding to botulinum toxin injection developed a symptomatic relapse 6 +/- 2 months after botulinum toxin treatment. These patients then achieved long-term clinical remission from pancreatic or combined (biliary and pancreatic, n=5) sphincterotomy (median follow-up, 15 months).
Conclusion: Endoscopic botulinum toxin injection into the papilla of Vater is a safe procedure for treatment of pancreatic sphincter of Oddi dysfunction that may provide short-term relief in about 80% of the patients. Those patients who respond to botulinum toxin may subsequently gain definitive cure from sphincterotomy.