POEM for Achalasia and Esophageal Motility Diseases: What Are the Knowledge Gaps?

Purpose of review Our goal in this focused review is to discuss areas of POEM where significant knowledge gaps exist. We identified two such important areas: (1) The role of POEM in non-achalasia motility disorders, particularly EGJOO, the most prevalent and problematic one. (2) Post-POEM GERD, including its prevalence, particularly in comparison to Heller, objective assessment, and techniques to prevent or treat it. Recent findings Regarding non-achalasia motility disorders, limited retrospective multicenter studies suggest that, compared to achalasia, POEM has lower efficacy for Jackhammer esophagus (JE) but equivalent efficacy for DES and EGJOO. However, higher-quality single-center studies found that, even with careful selection of EGJOO patients that meet criteria for true achalasia-like LES obstruction, POEM outcomes are inferior to those of POEM for achalasia. Regarding post-POEM GERD, higher-quality studies report more favorable prevalence rates than lower quality studies, particularly when GERD is measured objectively by pH studies, which show similar or only modestly higher acid exposure after POEM compared to Heller. Reflux esophagitis rates may be overestimated after POEM due to ischemic ulcers at the poorly vascularized mucosa overlying the tunnel scar. Furthermore, intriguing preliminary data suggest that post-POEM GERD may improve on long-term follow-up, unlike GERD after Heller. PPIs are highly effective and remain the cornerstone of management. However, preliminary data on GERD therapy using anti-reflux procedures such as TIF and the novel POEF procedure and on GERD prevention using POEM technique modifications such as the novel “anti-reflux” POEM are intriguing. Summary POEM appears less effective in JE and EGJOO compared to achalasia. More research is needed on how to optimally select patients with non-achalasia motility disorders that may benefit from POEM. GERD after POEM, when properly assessed with objective testing, may not be much different than after Heller in the long run. Promising initial data on POEM technique modifications to decrease GERD and adjunctive anti-reflux procedures such as TIF and POEF merit further investigation.