Characterization of gastroesophageal reflux disease after peroral endoscopic myotomy: interpreting acid exposure time in the context of pH-impedance patterns.

INTRODUCTION

Gastroesophageal reflux disease (GERD) can develop following peroral endoscopic myotomy (POEM). Despite reports of high rates of acid exposure time (AET), limited research examined acidification patterns or contributing factors using esophageal impedance-pH monitoring.

OBJECTIVE

To assess the incidence and characteristics of reflux after POEM by analysing esophageal acidification patterns on pH-impedance monitoring.

METHODS

We prospectively included patients with primary esophageal motility disorders who underwent POEM between June 2018 and October 2022. GERD was assessed at 3 and 12 months using clinical questionnaires, endoscopy, manometry, and pH-impedance testing evaluated by manual analysis.

RESULTS

Among 55 patients, GERD-Q score ≥8 was observed in 7% at 3 months and 9% at 12 months. Esophagitis occurred in 28% at 3 months and 24% at 12 months, with severe cases (grade C) in 7% and 5%, respectively. Pathologic AET was noted in 54% at 3 months and 52% at 12 months. After excluding "non-true acid reflux" (acid fermentation and esophageal stasis) by manual pH tracing review, GERD rates decreased to 46.3% and 36.3% at 3 and 12 months, respectively. Prior proton pump inhibitor use and longer esophageal myotomy were associated with clinical reflux (GERD-Q ≥8) at 12 months in exploratory multivariable analysis.

CONCLUSIONS

The incidence of post-POEM GERD is considerably lower after a detailed manual analysis of pH tracings; their review allows differentiation of non-true acid reflux in pathological AET. These findings highlight the importance of careful interpretation of pH-impedance monitoring when evaluating reflux after POEM.