Risk factors for clinical failure of peroral endoscopic myotomy in achalasia
Lucille Quénéhervé, Blandine Vauquelin, Arthur Berger, Emmanuel Coron, Raphaël Olivier
Abstract
The recent development of per oral endoscopic myotomy (POEM) has been a game changer in the management of patients with achalasia. However, approximately 1 in 10 patients will not experience clinical success. The aim of this mini-review is to describe the current state of knowledge about the risk factors associated with POEM failure for the treatment of achalasia. Suspected risk factors are detailed into pre-, intra-, and post-procedural factors and put into perspective. Pre-procedural factors have been described, such as pre-treatment Eckardt score, previous treatments for achalasia, sigmoid type esophagus, significant esophageal dilatation, non-type II achalasia, young age and long duration of symptoms. An intra-procedural factor, mucosal injury during POEM, has also been associated with POEM failure. The occurrence of post-POEM GERD was identified as a controversial post-procedural factor associated with failure. The presumed mechanisms of POEM failure are incomplete myotomy or ineffective LES disruption, as confirmed by high-resolution manometry. However, when manometry confirms a significant decrease in LES pressure, it is likely that either impaired peristalsis or a morphologic abnormality such as extreme esophageal dilatation or severe tortuosity, which are not treated by POEM, should be suspected. Notably, a recently described adverse effect of POEM is the formation of a pseudo-diverticulum at the site of the myotomy (blown out myotomy). We finally stress the importance of performing a complete workup in case of POEM failure as different mechanisms of POEM failure should lead to different management.