[Correlation of Matrix Metalloproteinases-9 with Microemboli Shedding in Carotid Endarterectomy]

Objective To investigate the change of serum matrix metalloproteinases-9 (MMP-9) expression before,during,and after carotid endarterectomy (CEA) and to investigate the prognostic role of MMP-9. Methods Forty carotid stenosis patients who underwent CEA in the Department of Vascular Surgery,Peking Union Medical College Hospital from February to September 2012 were enrolled in this study. Based on the findings of transcranial doppler monitoring,patients were divided into embolic-positive group and emboli-negative group. Serum samples were obtained from 40 consecutive patients undergoing CEA before operation (pre-op),before de-clamping,30 minutes after de-clamping,and 12 hours after operation (12-h post-op). MMP-9 expression was quantified using enzyme-linked immunosorbent assay and gelatin zymography. Student's t-test and chi-square test were used to compare the differences between these two groups. Results Of these 40 patients,microemboli were detected in 8 patients. The 12-h post-op MMP-9 level was significantly higher than the pre-op level in the emboli-positive group [(904.27±369.47)ng/ml vs. (333.88±126.32) ng/ml,t=4.132,P=0.001].However,there was no difference between pre-op and 12-h post-op MMP-9 levels in the emboli-negative group [(375.83±194.36) ng/ml vs. (472.74±271.21) ng/ml,t=-1.643,P=0.081]. Gelatin zymography also showed higher MMP-9 activity in the emboli-positive group than in the emboli-negative group. Conclusion Serum MMP-9 concentration remarkably increases 12 hours after CEA in patients with microemboli shedding,suggesting MMP-9 may be a potential biomarker for CEA-related cerebral ischemic injury.