POEM is a highly safe and effective treatment for esophageal achalasia with favorable long-term outcomes.

Peroral endoscopic myotomy (POEM) is now an established treatment for esophageal achalasia. The standard protocol ensures a smooth operation in most patients, but technical challenges and failures exist and little is known about the incidence, causes, and impact of aborted procedures. Here, using a large patient cohort, we attempted to answer these questions. All patients admitted for planned POEM between August 2010 and July 2015 underwent chart review. Aborted POEM was defined as the inability to finish the procedure after submucosal injection. The cause of the failure, clinical course, management, and follow-up data were analyzed.Thirteen of the 1693 POEMs (0.77 %) were aborted. Out of the 13 failures, 12 (92.3 %) were due to severe submucosal fibrosis, which precluded tunneling, and one (7.7 %) was due to atrial fibrillation related to the electric current of the endoscopic knife. Submucosal fibrosis, prior Heller myotomy, and age ( ≥ 60 years) were related to technical failure, while a disease duration of ≥ 6 years, sigmoid esophagus, mucosal edema, and prior interventions were risk factors for the presence of fibrotic changes. In turn, fibrosis was correlated with a prolonged operation, longer hospital stay, more mucosal injuries, and more major perioperative adverse events. Finally, the yearly frequency of aborted POEMs decreased after the second year as operators became more experienced. Aborted POEM is a rare event and is largely due to the presence of submucosal fibrosis, which not only causes increased procedural difficulties, but also gives rise to major adverse events.

Background Peroral endoscopic myotomy (POEM) is a treatment option for patients with previous surgical or endoscopic treatment. We aimed to evaluate the influence of prior treatment on perioperative and follow-up outcomes in patients undergoing POEM. Methods From August 2010 to December 2014, a total of 1384 patients with achalasia underwent POEM at our center. We retrospectively reviewed 849 patients who completed follow-up. Patients with an Eckardt score ≥ 4 after POEM were considered to have a clinical failure. We compared variables between patients with and without prior treatment. We analyzed risk factors for perioperative major adverse events, and clinical reflux and failure during follow-up.  Results 245 patients (28.9 %) had undergone prior treatment, and 34 patients (4.0 %) experienced a major adverse event associated with the POEM procedure. During a median follow-up of 23 months (range 1 – 71), clinical reflux occurred in 203 patients (23.9 %) and clinical failure was recorded for 94 patients (11.1 %). Patients with prior treatment had a longer procedure duration (P = 0.001) and longer hospital stay after POEM (P = 0.001). Prior treatment was not an independent risk factor for major adverse events or clinical reflux (odds ratio [OR] 1.19, P = 0.65; OR 1.26, P = 0.19; logistic regression), but it did increase the rate of clinical failure during follow-up (hazard ratio 1.90, P = 0.002; Cox regression). Conclusions POEM was performed safely with a low rate of major adverse events in patients with achalasia who had undergone prior surgical or endoscopic treatment. However, prior treatment increased the risk of clinical failure after POEM.