S. Y. Salim1, P. Young1, Y. Li1, T. A. Churchill1, R. G. Khadaroo1,2 1University Of Alberta,Div. Gen Surgery, Dept. Surgery,Edmonton, AB, Canada 2University Of Alberta,Div. Critical Care Medicine/ Dept Surgery,Edmonton, AB, Canada
Introduction:
Acute mesenteric ischemia (AMI) has a high morbidity and mortality and often presents as a diagnostic challenge. Currently there are no blood, urine or radiological tests that provide a definitive diagnosis of AMI. The aim of this study was to evaluate if intestinal fatty acid binding protein (I-FABP), especially detected in urine, can predict AMI in patients.
Methods:
Eighteen patients referred to the Acute Care Surgery service at University of Alberta Hospital with suspected AMI taken to the operating room for definitive diagnosis, were recruited. Pathological findings from surgical specimens confirmed gold standard diagnosis for intestinal ischemia. The patients found to be non-ischemic became the internal controls. ELISAs for I-FABP and IL-6 were done on blood and urine samples collected at the time of surgery.
Results:
Ten patients were diagnosed with AMI while 8 patients were non-ischemic. There was no difference in age or gender between ischemic and non-ischemic patients (65+21 vs. 53+17 years old, respectively; 4 females with no ischemia and 5 females in the ischemic group). Additionally, there was no difference in serum lactate and creatinine between the 2 groups. Serum IL-6 levels in patients with AMI were significantly higher than non-ischemic controls (0.6+0.2 ng/mL vs. 0.08+0.04 ng/mL, respectively, p<0.006). There was an increase in serum I-FABP in AMI patients, though it was not statistically significant compared to internal controls (11+4 ng/mL vs. 1.9+0,6 ng/mL, respectively, p=0.06). Alternatively, urine I-FABP was significantly higher in patients diagnosed with AMI than in controls (8.7+1.4 ng/mL vs. 2.5+0.7 ng/mL, respectively, p<0.002). The receiver operating characteristic (ROC) illustrated that urine I-FABP does discriminate between patients with AMI and controls (area under ROC=0.9, p<0.003).
Conclusion:
The traditional clinical marker, lactate, was not able to differentiate AMI from non-ischemic bowel. However, we found that urine I-FABP can be used as a non-invasive biomarker with high specificity and sensitivity for accurately diagnosing AMI in patients. A non-invasive accurate tool for AMI would facilitate a rapid treatment, while preventing unnecessary surgical interventions in high-risk patient populations.