Assessing the value of routine upper gastrointestinal contrast studies following bariatric surgery: a systematic review and meta-analysis

BackgroundUnderstanding 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.MethodsWe 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.ResultsUGI 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.ConclusionsThe 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.