Carotid atherosclerotic plaque characteristics are associated with microembolization during carotid endarterectomy and procedural outcome.
OBJECTIVE
During carotid endarterectomy (CEA), microemboli may occur, resulting in perioperative adverse cerebral events. The objective of the present study was to investigate the relation between atherosclerotic plaque characteristics and the occurrence of microemboli or adverse events during CEA.


METHODS
Patients (n=200, 205 procedures) eligible for CEA were monitored by perioperative transcranial Doppler. The following phases were discriminated during CEA: dissection, shunting, release of the clamp, and wound closure. Each carotid plaque was stained for collagen, macrophages, smooth muscle cells, hematoxylin, and elastin. Semiquantitative analyses were performed on all stainings. Plaques were categorized into 3 groups based on overall appearance (fibrous, fibroatheromatous, or atheromatous).


RESULTS
Fibrous plaques were associated with the occurrence of more microemboli during clamp release and wound closure compared with atheromatous plaques (P=0.04 and P=0.02, respectively). Transient ischemic attacks and minor stroke occurred in 5 of 205 (2.4%) and 6 of 205 (2.9%) patients, respectively. Adverse cerebral outcome was significantly related to the number of microembolic events during dissection (P=0.003) but not during shunting, clamp release, or wound closure. More cerebrovascular adverse events occurred in patients with atheromatous plaques (7/69) compared with patients with fibrous or fibroatheromatous plaques (4/138) (P=0.04).


CONCLUSIONS
Intraoperatively, a higher number of microemboli were associated with the presence of a fibrous but not an atheromatous plaque. However, atheromatous plaques were more prevalent in patients with subsequent immediate adverse events. In addition, specifically the number of microemboli detected during the dissection phase were related to immediate adverse events.
Department of Vascular Surgery, University Medical Centre, Utrecht, The Netherlands.
B A N
BA
Verhoeven
J P P M
JP
de Vries
G
G
Pasterkamp
R G A
RG
Ackerstaff
A H
AH
Schoneveld
E
E
Velema
D P V
DP
de Kleijn
F L
FL
Moll
D000328:Adult; D000368:Aged; D050197:Atherosclerosis / Q000175:diagnosis*; D002339:Carotid Arteries / Q000473:pathology*; D002341:Carotid Artery Thrombosis / Q000473:pathology; D016893:Carotid Stenosis / Q000473:pathology*; D003094:Collagen / Q000737:chemistry; D004549:Elastin / Q000378:metabolism; D004569:Electroencephalography; D004621:Embolization, Therapeutic / Q000009:adverse effects* / Q000379:methods*; D016894:Endarterectomy, Carotid / Q000379:methods*; D005260:Female; D006416:Hematoxylin / Q000378:metabolism; D006801:Humans; D007249:Inflammation; D007511:Ischemia; D008264:Macrophages / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008833:Microcirculation / Q000473:pathology; D008875:Middle Aged; D009130:Muscle, Smooth / Q000166:cytology; D010641:Phenotype; D011446:Prospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020521:Stroke / Q000378:metabolism / Q000473:pathology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014463:Ultrasonography; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D014945:Wound Healing
D003094:Collagen; D004549:Elastin; D006416:Hematoxylin