title: The incidence of "silent" free air and aspiration pneumonia detected by CT after gastric endoscopic submucosal dissection.
abstract: BACKGROUND
  Although endoscopic submucosal dissection (ESD) is feasible as a treatment for early gastric cancer, it requires great skill to perform and may place patients at increased risk of a number of complications, including perforation and aspiration pneumonia.
  
  
  OBJECTIVE
  To investigate the incidence of "silent" free air without endoscopic perforation and aspiration pneumonia detected by CT after ESD and risk factors for the development of these 2 conditions.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Single academic center.
  
  
  METHODS
  This study involved 87 patients with a total of 91 malignancies.
  
  
  METHODS
  All patients underwent chest and abdominal CT and blood biochemistry analysis before and 1 day after ESD.
  
  
  METHODS
  The incidence of silent free air and aspiration pneumonia after ESD and the related risk factors.
  
  
  RESULTS
  Silent free air was identified in 37.3% of patients without perforation. Tumor location (the upper portion of the stomach), the presence of a damaged muscular layer during ESD, and procedure time, but not specimen size, were significantly associated with silent free air (P = .006, P = .04, P = .02, and P = .53, respectively). According to the receiver-operating characteristic analysis, the resulting cutoff value of the procedure time for silent free air was 105 minutes (67.7% sensitivity, 65.4% specificity). Only procedure time (≥ 105 minutes) was an independent predictor of silent free air development (odds ratio 3.23; 95% confidence interval, 1.21-8.64; P = .02). On the other hand, aspiration pneumonia was seen in 6.6% of patients. Silent free air and aspiration pneumonia did not affect hospitalization.
  
  
  CONCLUSIONS
  Single center and small number of patients.
  
  
  CONCLUSIONS
  Silent free air is frequently observed after ESD, and longer procedure time (≥ 105 minutes) was an independent risk factor for silent free air. However, silent free air and aspiration pneumonia detected by CT are not associated with clinically significant complications.
authors.affiliation: Division of Upper Gastroenterology, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Watari
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Tomita
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Toyoshima
authors.forename: Jun
authors.initials: J
authors.lastname: Sakurai
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
authors.forename: Haruki
authors.initials: H
authors.lastname: Asano
authors.forename: Takahisa
authors.initials: T
authors.lastname: Yamasaki
authors.forename: Takuya
authors.initials: T
authors.lastname: Okugawa
authors.forename: Junji
authors.initials: J
authors.lastname: Tanaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Daimon
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Oshima
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Fukui
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Hori
authors.forename: Takayuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Hiroto
authors.initials: H
authors.lastname: Miwa
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery*; D000236:Adenoma / Q000601:surgery*; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005753:Gastric Mucosa / Q000601:surgery; D005773:Gastroscopy; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D061646:Operative Time; D011015:Pneumonia, Aspiration / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D011027:Pneumoperitoneum / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D013270:Stomach / Q000293:injuries; D013274:Stomach Neoplasms / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome