Intraoperative impedance planimetry (EndoFLIP™) results and development of esophagitis in patients undergoing peroral endoscopic myotomy (POEM)

Introduction Peroral endoscopic myotomy (POEM) is a minimally invasive treatment for achalasia. Considerable evidence demonstrates a high incidence of gastroesophageal reflux disease (GERD) after POEM. The endoluminal functional lumen imaging probe (FLIP) uses impedance planimetry to obtain objective measurements of the gastroesophageal junction. This study aims to determine whether FLIP measurements collected at the time of POEM are associated with the development of reflux esophagitis postoperatively. Methods Patients who underwent POEM between 2012 and 2019 who subsequently had esophagogastroduodenoscopy (EGD) were included. Intraoperative FLIP measurements before and after myotomy, clinical data from EGD, and reflux specific quality of life questionnaires were collected. Comparisons between groups were made using the Wilcoxon rank-sum and Fisher’s exact tests. Receiver operating characteristic (ROC) curves were used to determine optimal cutoffs of measurements to classify patients into those with high risk of postoperative esophagitis and those with lower risk. Results A total of 43 patients were included. Of those, 25 (58.1%) were found to have esophagitis on postoperative EGD: four patients (16%) with LA Grade A, five (20%) with LA Grade B, 11 (44%) with LA Grade C and two (8%) with LA grade D esophagitis. Patients with a final distensibility index ≥ 2.7 and a final cross-sectional area ≥ 83 were significantly more likely to develop esophagitis on postoperative EGD ( p = 0.016 and p = 0.008, respectively). Gastroesophageal reflux disease health-related quality of life (GERD-HRQL) and reflux symptom index (RSI) scores were not significantly different in patients who developed esophagitis and those who did not. Conclusion Reflux affects some patients after POEM. We show that FLIP measurements collected during POEM may help predict which patients are more likely to develop reflux esophagitis postoperatively. Subjective symptoms on quality of life questionnaires are not reliable in determining which patients are at risk for esophagitis.