Factors Associated with Symptom Response to Pyloric Injection of Botulinum Toxin in a Large Series of Gastroparesis Patients

Abstract

Case series report symptom reductions after pyloric botulinum toxin injection in gastroparesis, but small controlled trials show no benefit. Factors that enhance response to therapy are undefined. A retrospective analysis of 179 gastroparetics undergoing pyloric botulinum toxin injection from 2001 to 2007 assessed responses relating to drug dosing, demographic factors, comorbidities, and gastric function. Overall, there was a decrease in gastroparetic symptoms 1-4 months after pyloric botulinum toxin injection in 92 patients (51.4%). Increasing the botulinum toxin dose significantly improved clinical responses of patients who provided information on symptoms after therapy (100 units: 54.2%; 200 units: 76.7%; P=0.02). Other factors that improved response to botulinum toxin included female gender, age <50 years, and nondiabetic nonpostsurgical etiology (all P<0.05). Eighty-seven patients received 307 follow-up injections. A clinical response to a second injection was observed in 73.4% of evaluable patients. In conclusion, responses to pyloric botulinum toxin depended on dose and were maintained on repeat injection. Subgroup analyses defined subgroups likely to benefit. These findings provide the foundation for large, controlled trials of high-dose botulinum toxin in selected gastroparesis subsets.

Gastric per-oral endoscopic myotomy for refractory gastroparesis: results from the first multicenter study on endoscopic pyloromyotomy (with video)

“…3,4 Nonetheless, clinical experience and some studies have shown clinical benefit in some patients with gastroparesis. 5 Surgical management mainly encompasses placement of gastric electric stimulators. 6 However, this is FDA-approved at present only as a humanitarian use device.…”

The role of endoscopy in gastroduodenal obstruction and gastroparesis

“…In a retrospective cohort study of 179 patients, doses of 200 units were beneficial in a significantly greater proportion of patients than doses of 100 units (77% vs 54%, P ϭ .02). 77 In this same study, multivariate analysis showed that female sex, age younger than 50 years, and etiology other than diabetes or surgical vagal nerve manipulation were associated with an improved response to therapy. The reported duration of benefit from pyloric botulinum toxin ranges from 1 to 5 months, and repeated injections may be associated with the return of clinical response in a subset of patients.…”

“…Numerous uncontrolled studies have shown symptom reduction in patients with gastroparesis treated with pyloric botulinum toxin injection. [73][74][75][76][77] However, 2 placebo-controlled trials involving a small number of patients (55 total) showed no significant benefit. 76,78 If there are benefits from endoscopic botulinum toxin injection, they may depend on the dose used and patient selection.…”

“…The reported duration of benefit from pyloric botulinum toxin ranges from 1 to 5 months, and repeated injections may be associated with the return of clinical response in a subset of patients. 77,79 In patients with gastroduodenal dysmotility and symptoms refractory to medical or botulinum toxin therapy, placement of decompressive gastrostomy can be effective. 69,71 In a small (N ϭ 8) series of women with idiopathic gastroparesis, placement of a venting gastrostomy was associated with significant improvement in symptoms and weight gain that was sustained at 3 years.…”

Endoscopy in the Diagnosis and Management of Motility Disorders

“…Responses depended on toxin dose; subgroup analyses suggested that individuals most likely to respond to increasing BoTox doses included women, those under 50 years old, patients with non-diabetic, non-postsurgical gastroparesis, and possibly individuals without retained food, long-standing opiate use, or with severely delayed gastric emptying. Eighty-seven patients in this series underwent 307 repeat injections that were performed 1-43 months after initial therapy and the initial injection dose (100-200 units) did not affect the reinjection interval [76]. Large, sham-controlled studies are still needed before Botox injection for gastroparesis can be universally recommended [24].…”