Endoscopy, Table of Contents Endoscopy 2016; 48(10): 953DOI: 10.1055/s-0042-112575 Letters to the editor © Georg Thieme Verlag KG Stuttgart · New YorkPeroral endoscopic myotomy for sigmoid-type achalasia: the myotomy length and ways to facilitate the procedure Yuyong Tan , Deliang Liu , Jirong Huo Recommend Article Abstract Buy Article Full Text References References 1 Unn K, Chhorn P, Rivory J et al. Use of a long, stiff, overtube placed by a colonoscope to facilitate the POEM procedure for a 36-year history of achalasia with 13-cm esophageal dilation. Endoscopy 2016; 48: E172-173 2 Stavropoulos SN, Modayil RJ, Friedel D et al. The International Per Oral Endoscopic Myotomy Survey (IPOEMS): a snapshot of the global POEM experience. Surg Endosc 2013; 27: 3322-3338 3 Hu JW, Li QL, Zhou PH et al. Peroral endoscopic myotomy for advanced achalasia with sigmoid-shaped esophagus: long-term outcomes from a prospective, single-center study. Surg Endosc 2015; 29: 2841-2850 4 Lv L, Liu J, Tan Y et al. Peroral endoscopic full-thickness myotomy for the treatment of sigmoid-type achalasia: outcomes with a minimum follow-up of 12 months. Eur J Gastroenterol Hepatol 2016; 28: 30-36