Botulinum toxin may predict the outcome of endoscopic sphincterotomy in episodic functional post-cholecystectomy biliary pain

Objective. A retrospective clinical audit was carried out to identify whether relaxation of the sphincter of Oddi (SO) by botulinum toxin (BTX) injection can select patients with episodic functional post-cholecystectomy biliary pain who will benefit from endoscopic sphincterotomy. Patients and methods. Sixty-four patients complaining of functional post-cholecystectomy biliary pain with a frequency of at least four episodes per month had 100 units of BTX injected into their SO muscle in four aliquots. After review patients with a pain free interval following BTX injection of at least 4 weeks were offered biliary endoscopic sphincterotomy and their outcome assessed. Results. Of the 64 patients 46 (72%) had at least four pain free weeks after BTX therapy and 44 of these 46 patients (96%) went on to experience pain relief following endoscopic sphincterotomy. Of the 64 patients 41 had sphincter of Oddi manometry prior to BTX injection. Every patient with sphincter of Oddi hypertension defined by manometry and at least 4 weeks' pain relief following BTX (24) had pain relief following sphincterotomy. Fifteen (94%) of the 16 patients who did not undergo manometry but reported at least 4 weeks' pain relief after BTX had pain relief after sphincterotomy. Conclusion. Botulinum toxin relaxation of the SO may be a useful method of predicting the symptom response to endoscopic sphincterotomy in patients who have episodic functional biliary pain.