Diagnostic value of computed tomography for detecting anastomotic or staple line leakage after bariatric surgery

Background

Postbariatric anastomotic or staple line leakage (ASLL) is a dreaded complication with an incidence up to 1.6% and a leak-associated mortality of 5.0% to 16.7%. Feared low sensitivity of abdominal computed tomography (CT) for detecting ASLL is causing surgeons to omit CT and directly perform a diagnostic laparoscopy in patients with suspected ASLL.

Objectives

To evaluate the diagnostic value of CT in case of suspected ASLL after bariatric procedures and to identify reliable CT characteristics predicting the presence of ASLL.

Setting

A large teaching hospital and bariatric center of excellence.

Methods

All CT scans performed for suspected ASLL after bariatric surgery in the period November 2007 until August 2016 were independently reevaluated by abdominal radiologists. The diagnostic value of CT by means of sensitivity, specificity, and positive and negative predictive value was analyzed comparing results of reevaluation to a standard of reference. Multivariable regression was performed to identify reliable CT characteristics for the presence of ASLL.

Results

A total of 66 CT scans were performed because of suspected leakage. Reevaluation of CT scans revealed a sensitivity of 89% to 100%, a specificity of 69% to 78%, a positive predictive value of 39% to 50%, and a negative predictive value of 97% to 100% of CT for detecting ASLL after bariatric surgery. Multivariable logistic regression of ASLL characteristics on CT revealed ‘air near the anastomosis/staple line’ as the only independent predictor for the presence of ASLL.

Conclusion

With a sensitivity of 89% to 100% and negative predictive value of 97% to 100%, a negative CT can rule out ASLL in patients with a lower suspicion of ASLL.