Role of Functional Luminal Imaging Probe in the Evaluation and Management of Pediatric Esophageal Disorders

Assessment of esophageal function in pediatric populations remains challenging due to the limited biomechanical information provided by conventional diagnostic modalities. While upper endoscopy evaluates mucosal pathology, contrast radiography assesses anatomical features, and high-resolution manometry characterizes pressure dynamics and motility, these techniques do not directly measure esophageal compliance, distensibility, or wall stiffness. These biomechanical properties are increasingly acknowledged as critical determinants of symptom generation and disease progression. The functional luminal imaging probe (FLIP), commercially known as the endoluminal functional lumen imaging probe (EndoFLIP), utilizes impedance planimetry to measure luminal geometry and intrabag pressure during controlled distension. This method allows for the assessment of esophageal diameter, cross-sectional area, distensibility index, and contractile responses. Over the past decade, EndoFLIP has become an important adjunct in evaluating pediatric esophageal disorders, including achalasia, esophagogastric junction outflow obstruction, eosinophilic esophagitis, and other motility disorders. The advent of FLIP panometry has further expanded its utility by providing insights into distension-induced esophageal contractility. Its intraoperative application during peroral endoscopic myotomy and laparoscopic Heller myotomy has enabled real-time assessment of therapeutic effectiveness. However, current pediatric evidence is limited by small sample sizes, predominantly retrospective, single-center study designs, heterogeneous procedural protocols, and insufficient long-term outcome data. In addition, age-appropriate normative values, diagnostic thresholds, and therapeutic targets remain inadequately validated. This review examines the principles of EndoFLIP technology, its current pediatric applications, comparisons with high-resolution manometry, technical challenges, and future prospects. Available evidence suggests that EndoFLIP provides clinically valuable information that complements traditional diagnostic approaches and may increasingly inform the evaluation and management of pediatric esophageal disorders.