title: Elevation in plasma MMP-9 following carotid endarterectomy is associated with particulate cerebral embolisation.
abstract: OBJECTIVE
  To study plasma MMP-9 levels before and after carotid endarterectomy (CEA).
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Pre-operative (morning of surgery) and post-operative (48 h) plasma samples were obtained from 75 consecutive patients undergoing CEA. MMP-9 concentrations were quantified using ELISA. Transcranial Doppler monitoring was performed on each patient to detect particulate embolisation during the dissection phase of the CEA, until the application of carotid clamps.
  
  
  RESULTS
  The median post-operative plasma MMP-9 level of emboli-positive patients was significantly higher than their median pre-operative value (14.9 ng/ml vs. 8.8 ng/ml; p=0.038). However, no significant difference was seen in the plasma MMP-9 level of emboli-negative patients (7.7 ng/ml vs. 7.1 ng/ml; p=0.364). A greater rise was seen in the median plasma MMP-9 levels of those patients suffering >2 emboli (from 3.4 to 19.3 ng/ml; p=0.041) than those patients suffering 1 or 2 emboli (from 10.1 to 12.8 ng/ml; p=0.340).
  
  
  CONCLUSIONS
  Plasma MMP-9 only rises after CEA in patients with evidence of embolisation. This increase is more pronounced in those with high numbers of emboli. These data suggest that the increase in MMP-9 is due to cerebral damage caused by embolisation.
authors.affiliation: Department of Surgery, University of Leicester, UK.
authors.forename: K J
authors.initials: KJ
authors.lastname: Molloy
authors.forename: M M
authors.initials: MM
authors.lastname: Thompson
authors.forename: E C
authors.initials: EC
authors.lastname: Schwalbe
authors.forename: P R F
authors.initials: PR
authors.lastname: Bell
authors.forename: A R
authors.initials: AR
authors.lastname: Naylor
authors.forename: I M
authors.initials: IM
authors.lastname: Loftus
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002536:Cerebral Arteries / Q000000981:diagnostic imaging; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000097:blood*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D008875:Middle Aged; D011184:Postoperative Period; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood*; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D020780:Matrix Metalloproteinase 9