title: Factors predicting the technical difficulty of peroral endoscopic myotomy for achalasia.
abstract: Peroral endoscopic myotomy (POEM) has been described as a novel treatment for esophageal achalasia. Owing to its technical difficulty, POEM is not widely performed. This study was aimed to prospectively assess the factor predicting technical difficulty of POEM in a single center with large volume cases.
  
  
  
  A total of 105 cases of achalasia treated by POEM from April 2011 to September 2014 were analyzed. Difficult cases of POEM were defined as procedure time ≥90 min and occurrence of adverse events, including mucosal perforation, pneumothorax, and major bleeding. Univariate and multivariate logistic regression analyses were performed to assess the predictive factors of difficult POEM.
  
  
  
  POEM was successfully completed in all the patients, and no one was converted to laparoscopy. The number of cases with procedure time ≥90 min was 17. Mucosal perforations occurred in six (5.7 %) patients during submucosal tunnel creation, major bleeding occurred in seven (6.7 %) patients, and pneumothorax occurred in six (5.7 %) patients immediately after procedure. All the complications were managed conservatively. No other intraoperative and immediate postoperative complications, including infections and pneumoperitoneum, occurred. Multivariate analysis showed that early period (odds ratio [OR] 4.173, 95 % confidence interval [95 % CI] 1.36-6.829, P = 0.023) and triangular tip knife ([OR] 6.712, [95 % CI] 1.479-30.460, P = 0.014) were independent factors associated with technical difficulty regarding longer procedure time (procedure time ≥90 min).
  
  
  
  POEM is safe for the treatment of esophageal achalasia. Triangular tip knife and early period were independent risk factors for longer procedural time.
authors.affiliation: Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No.1838, Guangzhou North Ave, Guangzhou, 510515, China.|Department of Gastroenterology, Beijing Tsinghua Changgung Hospital Medical Center, Tsinghua University, Beijing, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Tang
authors.affiliation: Department of Gastroenterology, Beijing Tsinghua Changgung Hospital Medical Center, Tsinghua University, Beijing, China.
authors.forename: Yutang
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Gastroenterology, Beijing Tsinghua Changgung Hospital Medical Center, Tsinghua University, Beijing, China.
authors.forename: Zhengjie
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No.1838, Guangzhou North Ave, Guangzhou, 510515, China.|Department of Gastroenterology, Beijing Tsinghua Changgung Hospital Medical Center, Tsinghua University, Beijing, China.
authors.forename: Jieqiong
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No.1838, Guangzhou North Ave, Guangzhou, 510515, China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Deng
authors.affiliation: Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No.1838, Guangzhou North Ave, Guangzhou, 510515, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No.1838, Guangzhou North Ave, Guangzhou, 510515, China.|Department of Gastroenterology, Beijing Tsinghua Changgung Hospital Medical Center, Tsinghua University, Beijing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No.1838, Guangzhou North Ave, Guangzhou, 510515, China. drgwei@foxmail.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Gong
mesh_terms: D000293:Adolescent; D000328:Adult; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D004931:Esophageal Achalasia / Q000601:surgery*; D049630:Esophageal Sphincter, Lower / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D057605:Natural Orifice Endoscopic Surgery / Q000379:methods; D016017:Odds Ratio; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D055815:Young Adult
keywords: Complication; Esophageal achalasia; Peroral endoscopic myotomy; Predictor; Technical difficulty