Drain amylase levels in the early diagnosis of gastric leak after laparoscopic sleeve gastrectomy

Objectives: Laparoscopic sleeve gastrectomy is gaining popularity as a bariatric option. Gastric leak is the most dreaded septic complication after this procedure. This study investigated levels of drain amylase that could be useful for predicting gastric leak before its clinical presentation. Subjects and Methods: This prospective observational study was carried out in 167 patients who underwent sleeve gastrectomy for morbid obesity between February 2014 and March 2020. Measurement of drain amylase levels (DALs) was adapted as a routine procedure. The results of the receiver operative characteristic (ROC) curve analysis revealed an optimal drain amylase levels cutoff point of 814.18 IU/L. Consequently, the DALs were classified as DALs <814.18 or DALs ≥814.18 for all subsequent analyses. Results: Gastric leak occurred in 6 patients. Drain amylase levels of 167 patients were tested. The mean value for patients without leak was 71.13 ± 72.11 IU/L; for patients with leak, it was 4,687 ± 6,670 IU/L (p < 0.001). Using ROC curve analysis, the mean ± standard error of the area under the curve for DALs on postoperative day 1 was 0.9927 ± 0.0075, CI = 0.978-1.00, and a cutoff level at 814.18 IU/L for predicting gastric leak achieved 83.33% sensitivity and 100% specificity with positive predictive value of 100% and negative predictive value 99.38%. All patients with a leak, but one, had a drain amylase level >814.18 IU/L. Conclusion: The determination of drain amylase levels after sleeve gastrectomy is a significant indicator of gastric leak with high sensitivity and specificity.