Intrapyloric botulinum toxin is used in adults and children to treat gastroparesis when there are associated symptoms such as emesis. However, the authors of this retrospective, single center, openlabel study evaluated the ability of this treatment modality to improve feeding difficulties in children with associated gastrointestinal symptoms. All children aged 5 years of age or younger who had undergone intrapyloric botulinum toxin and who had a recorded follow up clinic visit within one year after injection were included. All patients underwent intrapyloric botulinum toxin dosing of 6 Units per kilogram (maximum of 100 Units) divided into 4 quadrant injections at the pylorus. Patient records were reviewed for baseline patient characteristics including use of enteral feeds and indication for intrapyloric botulinum toxin. Results of gastric emptying scans, upper gastrointestinal barium series, antroduodenal manometry, and esophagogastroduodenoscopy also were recorded. Patients with pseudo-obstruction were excluded from the study. Response to intervention was determined by a clinic follow-up appointment within one year of the intervention, and patients were characterized as having no improvement,partial improvement, and complete resolution depending on their outcome.
In total, 112 patients underwent intrapyloric botulinum toxin with 27 patients being excluded due to insufficient follow-up data, diagnosis of pseudo-obstruction, or the presence of an interval illness that made response interpretation difficult. The mean age of the study patients was 2.9 ± 1.6 years, and 65% of these patients had an enteral feeding tube of which 46% of such patients had a gastrostomy tube, 6% had a nasogastric tube, 47% had a gastrojejunal tube, and 2% had a nasojejunal tube. Gastric emptying studies were abnormal in 49% of study patients. Gastrointestinal symptoms leading to botulinum toxin use included emesis, retching, impaired oral intake, rumination, abdominal distention, nausea, inability to tolerate volume, and early satiety.
After intrapyloric botulinum toxin injection, 67% of patients had symptom improvement with 82% of these patients having partial improvement and 18% having complete symptom resolution. Additionally, significantly more patients were receiving some degree of oral feeds and significantly less patients were requiring postpyloric feeds after injection. Univariate analysis demonstrated that children less than 3 years of age had significantly greater improvement after injection compared to older children. Patients with rumination disorder showed no real improvement with injection therapy. Multivariate analysis demonstrated no specific variable that was associated with symptom improvement after intrapyloric botulinum toxin injection. It was noted that 14% of patients who underwent injection had subsequent medications added to their regimen to treat gastrointestinal symptoms; however, these patients had the same rate of improvement compared to patients who had no additional medication added. Only 15 of the initial 51 patients who underwent initial gastric emptying testing had repeat testing, and no significant difference was noted in one-hour gastric residual after injection therapy. In total, 29% of patients underwent repeat intrapyloric botulinum toxin injections within one year of the initial injection, and significantly more patients who underwent repeat injections had clinical improvement compared to patients with no improvement after an initial injection.
This study demonstrates that intrapyloric botulinum toxin may improve feeding difficulties in young children with associated gastrointestinal symptoms. The authors suggest that the lack of association between gastric emptying results and intrapyloric botulinum response indicates that botulinum toxin may work by improving sensory pathways. More research is needed to determine if intrapyloric botulinum toxin is a potential treatment for children with feeding disorders.
Hirsch S, Nurko S, Mitchell P, Rosen R. Botulinum toxin as a treatment for feeding difficulties in young children. The Journal of Pediatrics 2020; 226: 228-235.