A stepwise approach for peroral endoscopic myotomy for treating achalasia: from animal models to patients

Objectives. Peroral endoscopic myotomy (POEM) was initially developed for the treatment of achalasia. This study aimed to investigate the feasibility and safety of a stepwise approach for POEM in the management of achalasia. Methods. A total of five ex-vivo porcine esophagus-stomach training models were created and POEM was performed. Then, 25 patients with achalasia were treated similarly. The Eckardt score, barium esophagrams, and high-resolution manometry were used to evaluate its efficacy. Results. POEM procedures were completed in five stomach-esophagus models, with perforations in the initial three and success in the last two. A total of 36 achalasia patients (22 males, 14 females) with achalasia successfully underwent POEM. The mean operation time was 72.0 min (range, 45-180 min). There were two complications in three patients: one case of severe bleeding and two cases of pneumothorax, which were treated successfully. During the follow-up period, the median Eckardt score decreased dramatically from 8 to 1 (p = 0.000). The lower basal esophageal sphincter pressure (36.1 +/- 14.3 vs. 11.9 +/- 4.6 mmHg, p = 0.000), as well as the 4-s integrated relaxation pressure (12.9 +/- 13.0 vs. 6.6 +/- 2.9 mmHg, p = 0.000). Additionally, the maximum esophagus width was significantly reduced (mean reduced width: 1.6 +/- 1.1 cm, p = 0.000). Conclusions. The ex-vivo porcine esophagus-stomach can be used as a simple and cheap training model that mimics the POEM procedure. POEM is a safe and effective therapy for achalasia patients.