title: Assessing the value of routine upper gastrointestinal contrast studies following bariatric surgery: a systematic review and meta-analysis.
abstract: BACKGROUND
  Understanding both the efficacy of upper gastrointestinal (UGI) contrast studies and the factors that impact their accuracy is necessary to optimize postoperative imaging protocols. However, a consensus as to the value of UGI performed after bariatric surgery remains elusive. The objective was to determine the sensitivity and specificity of UGI conducted routinely within 2 days after bariatric surgery for detecting anastomotic leaks.
  
  
  METHODS
  We conducted an electronic search of MEDLINE for all English language articles published between 2003 and 2013 concerning diagnostic imaging after bariatric surgery. Nineteen studies evaluating a total of 10,139 patients met the inclusion criteria. The methodological quality of each included study was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 procedure.
  
  
  RESULTS
  UGI has an overall sensitivity of .54 and a specificity of 1.00. The standard deviation of the reported sensitivities was .36. Positive and negative predictive values were .67 and .98, respectively. Sensitivity and specificity were negatively correlated.
  
  
  CONCLUSIONS
  The sensitivity of UGI for detecting the presence of anastomotic leaks within 2 days of bariatric surgery is moderate overall but fluctuates substantially. The negative correlation between sensitivity and specificity could indicate that the threshold used to distinguish between positive and negative test results varies between institutions. Accordingly, clinicians may consider shifting the threshold for declaring a UGI positive; treating marginal radiological evidence of leakage as presumptively positive may be a simple way to lower specificity, increase sensitivity, and in turn maximize UGI's clinical value.
authors: Howard University College of Medicine, 520 W Street, Washington, DC 20059, USA.
authors: Tafari
authors: T
authors: Mbadiwe
authors: Howard University College of Medicine, 520 W Street, Washington, DC 20059, USA.
authors: Edward
authors: E
authors: Prevatt
authors: Department of Radiology, Howard University Hospital, 2041 Georgia Avenue NW, Washington, DC 20060, USA.
authors: Andre
authors: A
authors: Duerinckx
authors: Center for Wellness and Weight Loss Surgery, Howard University Hospital, 2041 Georgia Avenue NW, Washington, DC 20060, USA.
authors: Edward
authors: E
authors: Cornwell
authors: Center for Wellness and Weight Loss Surgery, Howard University Hospital, 2041 Georgia Avenue NW, Washington, DC 20060, USA.
authors: Terrence
authors: T
authors: Fullum
authors: Department of Radiology, Howard University Hospital, 2041 Georgia Avenue NW, Washington, DC 20060, USA. Electronic address: tafari.mbadiwe@gmail.com.
authors: Bonnie
authors: B
authors: Davis
mesh_terms: D057868:Anastomotic Leak / Q000000981:diagnostic imaging*; D050110:Bariatric Surgery; D003287:Contrast Media; D006801:Humans; D011182:Postoperative Care; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011859:Radiography; D012680:Sensitivity and Specificity; D041742:Upper Gastrointestinal Tract / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media
keywords: Bariatric surgery; Diagnostic accuracy; Upper gastrointestinal series