title: Pneumomediastinum is a frequent but minor complication during esophageal endoscopic submucosal dissection.
abstract: OBJECTIVE
  Esophageal perforation caused by endoscopic submucosal dissection (ESD) induces serious pneumomediastinum. In the absence of endoscopically detected perforation, postprocedural pneumomediastinum may occur. The aim of this study was to evaluate the association between the clinical factors/courses and pneumomediastinum revealed by chest computed tomography (CT) with special reference to an exposed muscle layer during esophageal ESD.
  
  
  METHODS
  A total of 58 patients undergoing ESD for esophageal neoplasms between February 2003 and June 2007 also underwent both chest radiography and chest CT within 1 hour after ESD. We studied the association between findings on CT scan and tumor-related and technical factors of esophageal ESD by uni- and multivariate analyses. We also analyzed the clinical factors/courses experienced by all patients.
  
  
  RESULTS
  Pneumomediastinum was detected in 18 / 58 patients (31 %) by chest CT compared with only 1 / 58 patients (1.7 %) by chest radiography. ESD-induced exposure of the muscular layer (32 patients) was the only significant factor for pneumomediastinum (18 / 32; P < 0.0001). Clinical factors such as fever, white blood cell count, and C-reactive protein were significantly increased in the group positive for both endoscopically exposed muscular layer and pneumomediastinum (+/+, n = 18) compared with the (-/-) group (n = 26) in the early phase (day 1) after ESD. However, these factors did not affect the length of the fasting period or the length of hospital stay.
  
  
  CONCLUSIONS
  In esophageal ESD, pneumomediastinum detected by chest CT only does not cause clinically significant complication. Endoscopic muscle exposure during ESD is a significant risk factor for pneumomediastinum, which causes mild inflammation in the early post-ESD phase.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Fukuoka 830-0011, Japan. tamiya_yoshitaka@kurume-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Tamiya
authors.forename: K
authors.initials: K
authors.lastname: Nakahara
authors.forename: K
authors.initials: K
authors.lastname: Kominato
authors.forename: O
authors.initials: O
authors.lastname: Serikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Watanabe
authors.forename: H
authors.initials: H
authors.lastname: Tateishi
authors.forename: H
authors.initials: H
authors.lastname: Takedatsu
authors.forename: A
authors.initials: A
authors.lastname: Toyonaga
authors.forename: M
authors.initials: M
authors.lastname: Sata
mesh_terms: D000368:Aged; D004210:Dissection / Q000009:adverse effects*; D004938:Esophageal Neoplasms / Q000601:surgery*; D004945:Esophagoscopy / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008478:Mediastinal Emphysema / Q000000981:diagnostic imaging* / Q000209:etiology*; D008875:Middle Aged; D011859:Radiography; D012307:Risk Factors; D016896:Treatment Outcome