Measuring platelet aggregation to estimate small intestinal ischemia-reperfusion injury

Background. The success of intestinal transplantation is affected by the extreme susceptibility of the small bowel to ischemia-reperfusion (I/R) injury. Currently, there is no quick, convenient method to estimate the extent of small bowel I/R injury. Although histological evaluation is reliable and accurate, it takes too long to allow favorable intervention in I/R injury. I/R causes the production of arachidonic acid products, oxygen free radicals, cytokines, and nitric oxide, which affect platelet function. Objective. This study determined whether measuring platelet aggregation is useful for evaluating small bowel I/R injury. Methods. Eighteen mongrel dogs were divided into three groups. In group A both the superior mesenteric artery (SMA) and vein (SMV) were occluded for 120 min. In group B the SMA was occluded for 60 min. Group C underwent a sham operation. Platelet aggregation was measured using a whole blood aggregometer (WBA analyzer), which readily handles small samples. Histological examination was performed. The correlation between platelet aggregation and histology was analyzed. Results. Platelet aggregation was similar in all groups before reperfusion. After reperfusion, platelet aggregation was significantly lower in group A than in groups B and C (P < 0.05), and mucosal damage was most severe in group A (P < 0.05). After I and 3 h of reperfusion, there was a significant negative correlation between platelet aggregation and histological damage. Conclusions. Measuring platelet aggregation is rapid, easy, and useful for evaluating small bowel I/R injury. (C) 2004 Elsevier Inc. All rights reserved.