Pyloric Metrics and Distensibility Plateau by Functional Luminal Imaging Probe in Pediatric Patients: A Pilot Study

BACKGROUND & AIMS: Pyloric dysfunction contributes to chronic nausea, vomiting, and abdominal pain in adults and children. The Functional Luminal Imaging Probe (FLIP) has been used in adults to characterize pyloric distensibility as a marker of muscular hypertonicity and to predict symptomatic improvement to intrapyloric botulinum toxin injection (IPBI). FLIP parameters that identify pyloric dysfunction in children are unknown. In this retrospective cohort study, we aimed to characterize the relationship of pyloric FLIP parameters to clinical symptoms, gastric emptying (GE), and antroduodenal manometry (ADM) findings in pediatric patients. Secondarily, we aimed to assess FLIP metrics as related to the subjective response to IPBI. METHODS: Chart review was performed for patients undergoing pyloric FLIP for refractory upper gastrointestinal symptoms at Lurie Children's Hospital. FLIP parameters were compared to symptoms, demographics, medical history, GE, ADM findings, and documented response to IPBI. The presence of a distensibility plateau (DP) was assessed. RESULTS: Ninety-nine patients underwent pyloric FLIP and 74 were treated with IPBI. Pyloric distensibility index (pDI) correlated with age and biological gender. Patients with chronic nausea, early satiety, concurrent pain disorders, joint hypermobility, and orthostatic intolerance demonstrated higher pDI compared to other symptoms. While pDI did not correlate with GE, it was lower in patients with normal fasting patterns on ADM and higher in IPBI responders. Nearly half of patients demonstrated a DP for which pDI was significantly higher in IPBI responders. CONCLUSIONS: This pilot study supports pyloric dysfunction as a mechanism underlying chronic upper gastrointestinal symptoms and would support prospective investigation of pyloric FLIP metrics in pediatrics.