A Systematic Review on Intrapyloric Botulinum Toxin Injection for Gastroparesis

Abstract

Background: Though trials evaluating the effect of intrapyloric botulinum toxin injection on gastroparesis have been reported, there is no agreement whether botulinum toxin can effectively relieve the symptoms and improve the results of gastric emptying study in patients with gastroparesis. We performed a systematic literature review to address this issue. Methods: Databases including PubMed, EMBASE, and the Cochrane Library and Science Citation Index were searched. Two reviewers independently identified relevant trials. Outcome measures were the improvement of subjective symptoms and objective measurement. Results: 15 reports were included; only 2 randomized controlled trials were available. Almost all the non-randomized trials reported significant improvement in subjective symptoms and objective gastric emptying study after botulinum toxin injection. While the 2 randomized controlled trials did not confirm the efficacy of botulinum toxin injection, none of the individual trials showed that there was statistically significant subjective and objective improvement in the active patients when compared with patients receiving placebo. Conclusions: Available high-quality trials showed that intrapyloric botulinum toxin injection could not significantly relieve subjective symptoms and improve objective measurement in patients with gastroparesis, and there is no evidence to recommend botulinum toxin injection for the treatment of gastroparesis.

Tetrahydrobiopterin (BH4), a cofactor for nNOS, restores gastric emptying and nNOS expression in female diabetic rats

“…Constitutively expressed NOS includes both nNOS and endothelial NOS (eNOS) isoforms (3). Because specific inhibitors for these individual isoforms are not available, we have measured total cNOS activity (cpm/mg protein) in pyloric homogenates following the method described by Bush et al (3). Figure 5A depicts that pyloric region of stomach contains maximum cNOS activity compared with fundus and antrum regions in ND group.…”

“…Recently, pyloric injection of botulinum toxin (BTX) has been tried in patients of gastroparesis, with both positive and negative outcomes. Even though BTX has been shown to reverse the gastric emptying in gastroparesis patients (24), it may not improve the symptoms (3,22). This may be because 1) nausea and vomiting may not correlate with emptying and 2) the site of action of BTX is localized to the pylorus where it is injected.…”

Pyloric Sphincter Therapy

“…36 A systematic review published in 2010 evaluated this issue and concluded after review of 15 reports that "there is no evidence to recommend botulinum toxin injection for the treatment of gastroparesis." 37 This finding was highlighted in the recent American College of Gastroenterology's clinical guideline on the management of gastroparesis where they gave a strong recommendation with a high level of evidence that "intrapyloric injection of botulinum toxin is not recommended for patients with gastroparesis based on randomized controlled trials," with the caveat that "there is a need for further study in patients with documented 'pylorospasm'." 2 In practice, however, botulinum toxin injection is still performed at many centers (including the authors' center) for refractory patients with gastroparesis who have not responded to conventional therapy and in whom pyloric dysfunction is suspected; although it is not routine and the data from randomized trials are discouraging, there may be subgroups that benefit, and it is important to recognize that both the published randomized trials had small sample sizes.…”

Postinfectious Gastroparesis

“…Finally, although not widely performed, pyloric injection with botulinum toxin is supported by few case reports 8,9 ; however, wider systematic reviews in adults are less encouraging. 10 …”