Background: Observational data suggest that intrapyloric injection of botulinum toxin A (BoTN/A) reduces symptoms and accelerates gastric emptying in idiopathic and diabetic gastroparesis. Our purpose was to determine whether botulinum toxin improves symptoms to a significantly greater extent than placebo. An additional objective was to determine whether there is an acceleration of gastric emptying after injection.
Methods: A single-institution, randomized, double-blind, placebo-controlled trial* was done. Eligible patients had a Gastroparesis Cardinal Symptom Index score > or = 27 with randomization to intrapyloric botulinum toxin, 200 U (units), or saline placebo. Reassessment of symptoms and repeat gastric emptying scan at 1-month follow-up were done.
Results: Thirty-two patients were randomized to botulinum toxin (N = 16) and placebo (N = 16). At 1-month follow-up, 37.5% randomized to botulinum toxin and 56.3% randomized to placebo achieved improvement as defined by this study. There were no identifiable clinical predictors of response. The botulinum toxin group demonstrated improvement in gastric emptying; however, this was not superior to placebo. No serious adverse events were attributable to botulinum toxin.
Conclusions: Intrapyloric injection of botulinum toxin improves gastric emptying in patients with gastroparesis, although this benefit was not superior to placebo at 1 month. Also, in comparison to placebo, symptoms do not improve significantly by 1 month after injection. Overall, we are unable to recommend botulinum toxin therapy for widespread use in the treatment of delayed gastric emptying until more data are available.