Introduction. Gastric leak after laparoscopic sleeve gastrectomy (LSG) is a severe complication that may lead to sepsis and even death. Early diagnosis and treatment are critical. The aims of this prospective study are to establish normal amylase levels and investigate elevated amylase levels, especially in the drain, for detecting anastomotic leakage following LSG. Material and Methods. One hundred sixty-one patients who underwent LSG during 1 year at Rambam Health Care Campus were included prospectively in the study. Demographic and medical background, peri- and postoperative complications, and laboratory data including amylase levels in blood, urine, and drain were evaluated. Univariate and multivariate analyses were performed to examine independent variables that can predict increases in amylase values. Results. Thirty-five (21.8%) patients had high levels of amylase in blood, urine, and/or drain and 126 (78.2%) normal values of amylase until discharge. No significant differences were found in operation duration, length of hospitalization, or occurrence of complications. One patient had a staple-line leak diagnosed in the third postoperative day that was treated conservatively with endoscopic approach. His amylase levels in the blood and drain were normal, with only a slight hyperamylasuria. Conclusions. High amylase levels after LSG does not necessarily indicate a major complication such as staple-line leak, and in the vast majority of cases, it seems to have no clinical relevancy. Therefore, it should not automatically lead to a full investigation in the absence of further clinical signs. It is suggested that there is no clinical justification to test amylase routinely after LSG.

Background Gastric leak post laparoscopic sleeve gastrectomy (LSG) is a severe complication that may lead to sepsis and even to patient's death. Early diagnosis and treatment are critical. It was hypnotized that the appearance of high levels of amylase, especially in the drain, may indicate a leak from the gastric staple line. The purpose of this prospective study was to examine the incidence of Amylase increase in the blood, urine and drain fluid, after LSG and to examine whether the appearance of high levels of Amylase indicates the existence of a major complication and especially a leak from the staple line. Methods From 161 patients whom underwent Sleeve gastrectomy, we prospectively evaluated the demographic information, including Body-mass-index (BMI), comorbidities, complications during the surgery or hospitalization, laboratory data including complete blood count, liver function tests, glucose and Amylase levels in blood, urine and drain. Testing for the normal distribution of the variables was performed using Kolmogorov-Smirnov test. Based on the results of this test we performed T- test or Mann-Whitney test to find differences between groups. Multivariate analysis using logistic regression was performed to examine the independent variables which can predict a rise in Amylase values above the upper limit number (ULN). Results Of 161 patients in this study, 35 patients (21.8%) had a rise in the Amylase values in blood, urine and/or drain, and 126 patients (78.2%) had normal values of Amylase until discharge. Amylase rise has been found to be correlated with Neutrophilia (OR = 5.4, p = 0.003), indirect hyperbilirubinemia (OR = 3.9, p = 0.022) and a decline in phosphate level (OR = 2.48, p = 0.019). Furthermore, a rise in Amylase is significantly associated to a rise in Aspartate and Aspartate transaminase transaminases (AST and ALT), Gamma-Glutamyl Transferase (GGT), Creatine-phosphokinase (CPK), Glucose and leukocytes, and a decline in lymphocytes and Calcium. No significant change was found in the duration of the operation and neither in the length of hospitalization. No specific complication was found to be significantly higher in any of the groups. One patient suffered from staple line leak and was treated conservatively. The diagnosis was done in post- operative day three by abdominal CT-scan. The amylase levels in the blood and the drain were normal and only a slight increase of amylase in urine was measured. Conclusions Increase in Amylase after LSG doesn't necessarily indicate a major complication such as staple line leak and in the vast majority of cases, it seems to have no clinical relevancy. Therefore, it should not automatically lead to a full clinical investigation in the absence of further clinical signs. Our results suggest that there is no clinical justification for Amylase tests in any method after LSG.