RESUMO
Leukotrienes (LTs), highly bioactive lipid mediators play a major role in inflammation, wound healing and in the development of atherosclerosis. LTs biosynthesis have been suggested to be increased in myocardial infarction (MI) and in surgical patients with abdominal aortic aneurysms. Among LTs, Cysteinyl-LTs have the most potent biological properties and their production is well reflected by LTE4 concentration in urine (uLTE4). Aim of the study was to evaluate perioperative biosynthesis of uLTE4 in noncardiac vascular surgery patients, and its impact on patients' outcomes. Twenty eight consecutive patients aged 61.5 (59.0-72.5) that undergone an elective surgery for abdominal aortic aneurysm (AAA; n=6) or peripheral artery disease (PAD; n=22) were studied. uLTE4 was measured in urine samples using ELISA: before surgery (LT0), 6 hours postoperatively (LT1), and on three following days (LT2-LT4), and the results were adjusted for the urinary creatinine concentration. Patients were followed-up for 30-days for cardio-vascular complications including myocardial infarction (MI) with active post-surgery troponin T screening. One way analysis of variance (ANOVA) for repeated measurements and logistic regression tests were used to analyse the data with P<05 considered significant. Excretion of uLTE4 raised in the first two urine sample (LT1 and LT2) after surgery as compared to preoperative baseline value (LT0) (P=0.008) and returned to normal values on the second day (LT3). Patients that suffered MI during postoperative period had increased uLTE4 levels when compared to the no-MI patients (P=0.006). In conclusion we state that uLTE4 biosynthesis is increased shortly after surgery and returns to the preoperative level on the second day. The increase in uLTE4 biosynthesis is higher in patients that suffer MI after surgery, however this warrants further investigations.