Endoscopic pyloric injection of botulinum toxin A for the treatment of refractory gastroparesis

Background: Botulinum toxin A injected into the pyloric sphincter has been reported in small case series to treat gastroparesis. This study reviews the use of this treatment in a large number of patients with gastroparesis. Methods: Patients who underwent pyloric botulinum injection for treatment of gastroparesis were identified. Response was defined as improvement or resolution of the patient's major symptom and/or two minor symptoms for 4 weeks. Results: Of 115 patients treated, 63 patients met the study criteria. There were 53 women, 10 men, mean age 42 years. Most patients (56%) had idiopathic gastroparesis. Twenty-seven of 63 (43%) patients experienced a symptomatic response to treatment. By stepwise logistic regression, male gender was associated with response to treatment (OR 3.27: 95% CI[1.31, 8.13],p = 0.01). Vomiting as a major symptom was associated with a lack of response (OR 0.16: 95% CI[0.04, 0.67], p = 0.01). Despite the association of male gender with response, the mean duration of response for those patients responding, with a minimum of 3 months' follow-up was 4.9 months (+/- 2.7 months) for women and 3.5 months (+/- 0.71 months) for men (P = 0.59). The corresponding medians and interquartile ranges (IQR) were 5 (IQR 3-6) for females and 3.5 (IQR 3-4) for males. Conclusions: Of the patients, 43% had a response to botulinum toxin treatment that lasted a mean of approximately 5 months. Male gender was associated with a response to this therapy; however, durability of response was unrelated to gender. Vomiting as a major symptom predicted no response.