Drain Amylase: A Simple and Versatile Method of Detecting Esophageal Anastomotic Leaks

BACKGROUND Anastomotic leak after esophagectomy is a significant cause of morbidity. Perianastomotic drain amylase is accurate in detecting leaks, but it is unclear whether its accuracy is affected by comorbid conditions, anastomotic method, or anastomotic location. We hypothesized that drain amylase would accurately discriminate leak in a variety of settings. METHODS We reviewed 290 consecutive patients undergoing esophagectomy with gastric conduit reconstruction. Patient comorbidities, operative variables, and drain amylase were collected. The diagnosis of a leak was based on the level of intervention required, and was characterized as clinically significant if it required wound opening or endoscopic or surgical intervention. Receiver-operating characteristic curves analysis was performed to determine the accuracy of amylase to detect leak for each patient variable. RESULTS A total of 53 (18.3%) of 290 esophagectomies had an anastomotic leak, of which 33 (11.4%) of 290 were clinically significant. Drain amylase was a strong predictor of anastomotic leak on postoperative day (POD) 3 to POD 7, regardless of patient comorbidities, location of anastomosis, or technique of anastomosis, but was less accurate in the diagnosis of leak in current smokers (area under the receiver-operating characteristic curve, 0.530 vs 0.752; P = .006). A maximum drain amylase value no higher than 35 on POD 3, POD 4, or POD 5 was 88% sensitive in detecting leak at any point postoperatively. A value greater than or equal to 150 was 88% specific in diagnosing leak. CONCLUSIONS Drain amylase is a versatile method for early detection of anastomotic leaks. Its accuracy is unaffected by neoadjuvant treatment, location or type of anastomosis, or patient comorbidities but may be less accurate in active smokers. (C) 2022 by The Society of Thoracic Surgeons