THE PREVALENCE OF PATHOLOGICAL ACID REFLUX AND ASSOCIATED SEQUELAE FOLLOWING PER-ORAL ENDOSCOPIC MYOTOMY: A SINGLE CENTRE EXPERIENCE

Aims Per-oral Endoscopic Myotomy (POEM) is an effective treatment for achalasia with outcomes comparable to Heller’s myotomy. However, the development of pathological acid reflux and subsequent Barrett’s oesophagus or malignancy is a subject of controversy. This study aims to determine the prevalence of acid reflux and associated sequelae following POEM for the treatment of achalasia.

Methods This was a retrospective study of 126 patients undergoing POEM as part of routine care between 2013-2019. Following POEM all patients were offered 24-hour pH testing and completed a reflux symptom questionnaire (GERD-HRQL) at 3-months. Surveillance gastroscopy was offered at 3-yearly intervals post POEM. The primary outcome measure was an abnormal total acid exposure time (>4.2%), presence of Barrett’s oesophagus or oesophageal neoplasia following POEM.

Results 34.1% (43/126) of patients completed 24-hour pH studies. 25.6% (11/43) patients had an abnormal total acid exposure time (AET) and elevated De Meester score (>14.72). There was no significant difference in age (p=0.28), disease duration (p=0.43), baseline eckardt score (p=0.90) or length of myotomy (p=0.25) between patients with a normal and abnormal AET. The majority (77.8%) of cases with an abnormal AET had little to no symptoms of acid reflux (GERD-HRQL score: 0-3). On post POEM surveillance gastroscopy 20.0% (4/20) of cases had evidence of reflux oesophagitis, including 1 case with normal AET on prior 24-hour pH testing. There were no cases of Barrett’s oesophagus or malignancy.

Conclusions This study established the prevalence of acid reflux on pH testing and surveillance gastroscopy following POEM was lower than suggested by prior studies. Surveillance gastroscopy and pH studies are advocated as part of routine care given many patients may be asymptomatic despite having physiological evidence of pathological acid reflux.