EndoFLIP assessment of pyloric sphincter in children: a single-center experience

Background: Gastrointestinal complaints are common in children with neurodisabilities, vomiting, retching and poor feed tolerance are frequently reported. Endolumenal functional lumen imaging probe (EndoFLIP) is used to assess compliance and distensibility of the pylorus and can predict response to Botulinum Toxin in adult with gastroparesis. We aimed to review pyloric muscle measurements using EndoFLIP in children with neuromuscular disabilities and significant foregut symptoms and to assess the clinical response to intrapyloric Botulinum Toxin. Methods: Retrospective review of clinical notes of all children who underwent pyloric EndoFLIP assessment in Evelina London Children's Hospital from March 2019 to January 2022. EndoFLIP catheter was inserted at the time of endoscopy via existing gastrostomy tract. Results: A total of 335 measurement from 12 children were obtained, mean age 10.7 +/- 4.2 years. Measurements (pre and post Botox) were obtained with 20, 30 and 40 mL balloon volume. Diameter (6.5, 6.6), (7.8, 9.4) and (10.1, 11.2), compliance (92.3, 147.9), (89.7, 142.9) and (77, 85.4) mm3/mmHg, distensibility (2.6, 3.8), (2.7, 4.4) and (2.1, 3) mm(2)/mmHg and balloon pressure was (13.6, 9.6), (20.9, 16.2) and (42.3, 35) mmHg. Eleven children reported clinical symptom improvement after Botulinum Toxin injection. Balloon pressure was positively correlated to diameter (r=0.63, P<0.001). Conclusions: Children with neurodisabilities who present with symptoms suggestive of poor gastric emptying do have a low pyloric distensibility and poor compliance. EndoFLIP via existing gastrostomy tract is quick and easy to perform. Intrapyloric Botulinum Toxin appears to be safe and effective in this cohort of children leading to clinical and measurements improvement.