Abstract
Background and Study Aims: Endoscopic sphincterotomy is not without risks, and is also ineffective in about
half of patients with type III sphincter of Oddi dysfunction (SOD), i.e. those without
clinical evidence of biliary obstruction (normal liver tests, normal bile duct diameter,
and regular drainage time at endoscopic retrograde cholangiography). The present study
therefore investigated the efficacy and safety of endoscopic botulinum toxin (BTX)
injection into the papilla of Vater, and analyzed whether the symptomatic response
to BTX injection might be a predictor of outcome for endoscopic sphincterotomy.
Patients and Methods: Twenty-two patients who had undergone cholecystectomy and had manometrically confirmed
type III SOD were enrolled during a three-year study period. All patients received
treatment with an endoscopic single-shot injection of 100 mouse units of BTX into
the papilla of Vater. Initial symptomatic responses were analyzed six weeks later.
If the BTX injection had been ineffective, or if biliary symptoms recurred after initial
benefit during the follow-up period, endoscopic manometry and endoscopic sphincterotomy
were performed. All patients then received further prospective clinical follow-up
examinations.
Results: With the exception of one patient with mild pancreatitis (4.5 %), no side effects
were observed after endoscopic BTX injection. Six weeks after BTX injection, 12 SOD
patients (55 %) were symptom-free, but ten patients (45 %) were not. However five
of these ten SOD patients who did not experience symptomatic benefit from BTX injection
had normal basal sphincter of Oddi pressures (< 40 mmHg) at this time, and none of
these five patients was free of complaints after subsequent endoscopic sphincterotomy.
Two of the remaining five patients with sustained sphincter hypertension after BTX
injection benefitted from endoscopic sphincterotomy. Eleven of the 12 SOD patients
who had initially responded to BTX injection developed recurrent symptoms after a
median period of six months. Manometry revealed sphincter hypertension in all 11 cases,
and all patients became free of complaints again after endoscopic sphincterotomy during
a median follow-up of a further 15 months. Overall, 11 of the 12 patients who responded
to BTX injection, versus two of the ten patients who did not gain pain relief after
BTX injection, later benefitted from endoscopic sphincterotomy (p < 0.01).
Conclusions: Endoscopic injection of botulinum toxin into the papilla of Vater is a safe procedure
and provides short-term relief of symptoms in half of patients with type III SOD.
Our results also indicate that the clinical response to BTX injection can predict
whether SOD patients will gain long-term benefit from endoscopic sphincterotomy.
