Peroral Endoscopic Myotomy Leads to Higher Rates of Abnormal Esophageal Acid Exposure Than Laparoscopic Heller Myotomy in Achalasia

Background And Aims: Peroral endoscopic myotomy (POEM) may be associated with higher rates of gastroesophageal reflux disease (GERD) than laparoscopic Heller's myotomy with fundoplication (LHM), since POEM is not combined with a fundoplication. However, peri-esophageal anti-reflux barriers are preserved in POEM, which might prevent GERD. Hence, we sought to compare the objective esophageal pH study findings in achalasia patients after POEM and LHM.

Methods: Achalasia patients undergoing POEM from 2014 to 2015 at our institution were matched 1:3 with LHM patients using propensity score matching. Demographics, prior interventions, pre-treatment and 2-month post-treatment timed barium esophagram (TBE), high-resolution esophageal manometry (HREM) and 24-h esophageal pH study findings were compared between the two groups.

Results: Thirty-one patients in the POEM group and 88 patients in the LHM group were included. Larger proportion of POEM patients had prior interventions for achalasia as compared to LHM patients (overall: 71% vs. 44.3%; p = 0.012). Esophageal acid exposure was significantly higher in POEM as compared to LHM patients (abnormal total acid exposure: 48.4% vs. 13.6%; p < 0.001, abnormal DeMeester score 54.8% vs. 17.4%; p = 0.005 respectively). In sub-group analysis, similar results were noted on 24-h pH study after exclusion of the POEM patients with prior LHM and corresponding matches. There was no significant difference in the rate of GERD symptoms between POEM and LHM. There was no significant correlation between the post-treatment basal lower esophageal sphincter pressure and integrated relaxation pressure with abnormal acid exposure in either POEM or LHM.

Conclusions: In patients with achalasia, POEM leads to significantly higher rates of abnormal esophageal acid exposure, without an increase in the rate of GERD symptoms, when compared to LHM with fundoplication. Interestingly, prior LHM has no impact on post-POEM pH study findings. Potential of increased esophageal acid exposure and possible consequences should be discussed with all patients prior to POEM. Further studies are needed to determine the long-term effects of increased acid exposure after POEM.