Defining “true acid reflux” after peroral endoscopic myotomy for achalasia: a prospective cohort study

The symptoms of reflux in achalasia patients undergoing per-oral endoscopic myotomy (POEM) are believed to result from gastroesophageal reflux, and the current treatment primarily focuses on acid suppression. Nevertheless, other factors such as non-reflux acidification caused by fermentation or stasis might play a role. This study aims to identify patients with "true acid reflux" who actually require acid suppression and fundoplication.In this prospective large cohort study, the primary objective was to assess the incidence and risk factors for "true acid reflux" in achalasia patients undergoing POEM. Acid reflux with normal and delayed clearance defined the "true acid reflux", while other patterns were labelled as "non-reflux acidification patterns" on manual analysis of pH tracings. These findings were corroborated with symptom questionnaire, esophagogastroscopy, esophageal manometry, timed barium esophagogram at 3 months after the POEM procedure.54 achalasia patients, aged 18-80 years [mean age 41.1 years (12.8), 59.3% males, 90.7% type II achalasia] underwent POEM resulting in significant mean Eckardt score improvement (6.7 to 1.6;p<0.05). "True acid reflux" was noted in 29.6% as compared to 64.8% on automated analysis. Acid fermentation was the predominant acidification pattern seen in 42.7% patients. On multivariable logistic regression analysis, increasing age (OR,1.12;95%CI,1.02-1.27;p=0.04) and pre-procedural integrated relaxation pressure (IRP) (OR,1.13;95%CI,1.04-1.30;p=0.02) were significantly associated with "true acid reflux" in post-POEM patients.A manual review of pH tracings helps identifying "true acid reflux" in post-POEM achalasia patients. Pre-procedural IRP can be a predictive factor in determining patients at risk for this outcome.