Periprocedural safety profile of peroral endoscopic myotomy (POEM)—a retrospective analysis of adverse events according to two different classifications

Background Peroral endoscopic myotomy (POEM) is nowadays a standard method for treatment of achalasia; nevertheless, it remains an invasive intervention with corresponding risk of adverse events (AEs). The classification and grading of AEs are still a matter of discussion. The aim of our retrospective study was to assess the occurrence of all “undesirable” events and “true” adverse events in patients undergoing POEM and to compare the outcomes when either Clavien–Dindo classification (CDC) or American Society of Gastrointestinal Endoscopy (ASGE) lexicon classification applied. Methods This was a retrospective analysis of prospectively managed database of all patients who had undergone POEM between December 2012 and August 2018. We assessed the pre-, peri-, and early-postoperative (up to patient’s discharge) undesirable events (including those not fulfilling criteria for AEs) and “true” AEs according the definition in either of the classifications. Results A total of 231 patients have successfully undergone 244 POEM procedures (13 × re-POEM). Twenty-nine procedures (11.9%) passed uneventfully, while in 215 procedures (88.1%), a total of 440 undesirable events occurred. The CDC identified 27 AEs (17 minor, 10 major) occurring in 23/244 (9.4%) procedures. The ASGE lexicon identified identical 27 AEs (21 mild or moderate, 6 severe or fatal) resulting in the severity distribution of AEs being the only difference between the two classifications. Only the absence of previous treatment was found to be a risk factor [ p = 0.047, OR with 95% CI: 4.55 (1.02; 20.25)] in the combined logistic regression model. Conclusion Undesirable events are common in patients undergoing POEM but the incidence of true AEs is low according to both classifications. Severe adverse events are infrequent irrespective of the classification applied. CDC may be more appropriate than ASGE lexicon for classifying POEM-related AEs given a surgical nature of this procedure. Graphical abstract