S426 POEM Results in More Frequent and More Severe Reflux Than Heller Myotomy

Abstract

Introduction: Achalasia is an esophageal motility disorder that is characterized by abnormal lower esophageal sphincter (LES) relaxation due to disrupted neuromodulatory responses. Relieving this outflow obstruction simultaneously disrupts the barrier against gastroesophageal reflux (GER). There is a need for comprehensive studies describing the comparative incidence of abnormal GER accounting for both pH testing and esophagogastroduodenoscopy (EGD) findings and specifically examining the incidence of severe reflux in peroral endoscopic myotomy (POEM) compared to laparoscopic Heller myotomy with Dor fundoplication (LHM). Methods: The charts of patients who underwent LHM or POEM between 2017 and 2019 at our institution were reviewed, and patients who had completed a 2-month post-treatment esophageal pH study off acid-lower agents were included. We also included patients who underwent EGD but did not undergo pH monitoring due to finding erosive esophagitis. Patients with a history of prior myotomy or who underwent Heller without Dor fundoplication were excluded. Results: Of the 236 patients included, 85 (36%) had undergone POEM while 151 (64%) had undergone LHM. The prevalence of abnormal gastroesophageal reflux using pH testing (TAE >4%) is 62% for POEM and 21% for LHM. When including abnormal EGD’s, the prevalence of abnormal GER (TAE >4% or reflux esophagitis or esophageal ulcer) becomes 72% and 28%, respectively. The incidence of severe reflux (defined by more than 10% time in reflux overall or Grade C/D esophagitis or esophageal ulcer) is 38.8% for POEM and 15.2% for LHM. The prevalence of gastritis was 7.9% in LHM vs 2.4% in POEM (NS), with a prevalence of gastric and duodenal ulcers of 2.6% in LHM vs 0% in POEM, but these were not statistically significant (Table). Conclusion: POEM is associated not only with a significantly higher incidence of abnormal GER (72% vs 28%, p< 0.001), but also with a higher incidence of severe GER (38.8% vs 15.2%, p< 0.001), accounting for both esophageal pH testing and upper endoscopy findings. Gastroenterologists should be aware of this association and follow post-POEM patients carefully given the risk of developing significant pathology due to severe reflux. Table 1. - Incidence of gastroesophageal reflux (GER) by different measures in POEM as compared to LHM Characteristic POEM LHM p-value TAE time >4% 62.4% 20.5% < 0.001 TAE time >10% 35.3% 10.3% < 0.001 Grade A/B esophagitis 17.6% 9.3% NS Grade C/D esophagitis 2.4% 6.6% 0.03 Esophageal Ulcer 1.2% 0.7% NS Gastroduodenal pathology* 2.4% 10.6% 0.022 Abnormal GER** 72% 28% < 0.001 Severely abnormal GER*** 38.8% 15.2% < 0.001 p-value significant if p4% or esophagitis. Severely abnormal GER was defined as TAE >10% or Grade C/D esophagitis or esophageal ulcer.