Reply to Eleftheriadis and to Sharma et al.

We read with interest the correspondence from Eleftheriadis and from Sharma et al. regarding our article exploring gastroesophageal reflex (GER) after peroral endoscopic myotomy (POEM) [1]. Unfortunately, we believe the intention of the study and the interpretation of our presented data has been taken out of context. Our study was not devised to decipher whether POEM should be performed or not. We concur that POEM has demonstrated excellent efficacy and procedural safety. The purpose of investigating post-POEM GER was to better contextualize it.

Our results were based on data submitted from seven centers which were subsequently analyzed and appropriately published, free from editorializing. We provided copious numbers of tables such that the data were transparent and easy to discern. The reported rate of post-POEM GER occurring in 58 % of patients in our study must be interpreted with reference to: (a) reflux being defined based on pH testing; (b) patients with GER being more likely to present for follow-up pH testing; and (c) the high proportion of caucasian patients. The rate of erosive esophagitis (including Los Angeles [LA] grade A) in our study was consistent with other groups at 23 %, demonstrating that endoscopy alone may not be an adequate investigation for post-POEM GER [2].

The study population that did not have a Chicago classification (22 %) may have contained individuals with spastic esophageal motility disorders; however, we do not have evidence that a particular classification is predictive of post-POEM GER. There were 167 patients with data available concerning hiatal hernia; it was present in only 1 patient (0.6 %).

We agree that the use of proton pump inhibitor (PPI) as a surrogate marker for symptomatic GER has limitations and that the performance of pre- and post-GER questionnaires would be superior. The risk of development of Barrett’s esophagus post POEM remains energetically debated and elucidation will require a large randomized prospective evaluation with 10-year follow-up including frequent surveillance endoscopies. Of concern though, new-onset Barrett’s has been reported within 3 years post POEM and should not be considered a benign condition [3].

To date, there do not appear to be data to suggest that patients undergoing procedures during the learning curve had a greater propensity to GER. In fact, it could be argued that there may be a greater risk of incomplete myotomy and this would conceivably be protective regarding GER. Additionally, the POEM technique has evolved only very subtly over the last 8 years, making changes in technique over time an unlikely explanation of our high reported prevalence of GER. We concur that prospective randomized evaluation of procedural techniques is necessary, as demonstrated by a prospective randomized study comparing anterior versus posterior myotomy (NCT02454335).

• References

• 1 Kumbhari V, Familiari P, Bjerregaard NC. et al. Gastroesophageal reflux after peroral endoscopic myotomy: a multicenter case-control study. Endoscopy 2017; 49: 634-642
• 2 Kahrilas PJ, Katzka D, Richter JE. Clinical practice update: the use of per-oral endoscopic myotomy in achalasia: expert review and best practice advice from the American Gastroenterological Association. Gastroenterology 2017; pii: S0016-5085(17)36201-7. DOI: 10.1053/j.gastro.2017.10.001. [Epub ahead of print]
• 3 Werner YB, Costamagna G, Swanstrom LL. et al. Clinical response to peroral endoscopic myotomy in patients with idiopathic achalasia at a minimum follow-up of 2 years. Gut 2016; 65: 899-906