thrombogenicity and platelet reactivity as risk factors for postoperative microemboli signals in patients undergoing carotid endarterectomy

Atherosclerosis is one of the most important causes of morbidity and mortality
in western society. This major problem merits particular attentention with
regard to research, in order to optimise the prevention, the care and the
treatment of tis disease.
An ischaemic stroke is often the result of atherosclerosis in the carotid
artery. The diagnostics and treatment of a recent stroke or a recent TIA is
partly based on the degree of stenosis found in the carotid artery. A surgical
intervention, named carotid endarterectomy, using the current indication
criteria (stenosis > 70%) has prooved to be effective in the reduction of
recurrent strokes. However, of all patients undergoing this intervention, 2-7%
develops a stroke in the postoperative phase. Nowadays transcranial doppler
sonographie is often used postoperatively in order to detect micro-embolisms
(MES), because in literature there is a growing evidence of a correlation
between the amount of MES and the occurence of a stroke.
Both coagulation parameters and platelet reactivity are considered to play an
important role in the formation of such micro-embolisms. The determination of
these parameters will result in a beter identification of patients at risk of
developping postoperative stroke.

The objective of this study is to predict which patients will develop MES after
carotid endarterectomy, using different coagulation parameters and platelet
function tests, so in the future these patients will be indentified early.
Identification of this subgroup may lead to a more adequate and early
intervention for these patients.

100 patients undergoing carotid endarterectomy will be included in the study.
Before the surgical intervention coagulation parameters and platelet function
will be determined using different laboratory test. Durin operation one more
blood samplewill be obtained,10 minutes after the injection of heparin. After
the operation patients will be monitored using TCD, starting from the first
postoperative hour during 3 hours. Subsequently we will investigate whether or
not there is a correlation between the markers and the amount of postoperative
MES. Also correlations between markers and the occurence of stroke will be
investigated. There will be a follow-up period of 21 year.

There are no risk related to TCD. All the risk of these study will be related
to the venepunctures. Bruises resulting from the venepuncture is a common
complication, but not harmful. Also thrombophlebitis might occur, although this
is rare complication.