Biomarkers for Postoperative Intimal Hyperplasia

Interleukin-8 (IL-8) is a neutrophil chemotactic factor produced by vascular endothelial cells. This study aimed to evaluate whether the serum IL-8 level can be the biomarker for postoperative intimal hyperplasia in the rat model. Sixteen male Lewis rats (mean weight: 501 ± 44 g) were subjected in this study. The right epigastric vein graft is interposed into the common femoral artery with 10-0 interrupted sutures, as previously described. Vein grafts from each group were stained with hematoxylin and eosin and Elastica Verhoeff's van Gieson's at 2 and 4 weeks postoperatively. Unoperated right epigastric veins were also examined as a Sham. In Group edaravone, free-radical scavenger, edaravone (Radicut ^® , Mitsubishi Tanabe Pharma Corp., Osaka Japan) was administered, instead of saline. The initial areas of vein grafts were measured using computerized planimetry (NIH Image Ver. 1.61). Serum IL-8 levels were measured and compared using an unpaired t -test. This study was approved by the Hyogo College of Medicine Animal Research Committee (No. 235). The average intimal area at 4 weeks in Control group was significantly increased compared with that of Sham group (0.43 ± 0.11 vs. 0.00 ± 0.00 mm ² , p  < 0.01). The average serum IL-8 levels at 4 weeks were also significantly increased, compared with that of Sham group (148 ± 6 vs. 53 ± 14 pg/mL, p  < 0.05). The serum IL-8 levels in Group edaravone were appeared to be suppressed but not significant (132 ± 24 pg/mL, p  = 0.72). It is very important to detect the biomarker such as the serum IL-8, before the establishment of postoperative intimal hyperplasia.