Perioperative stroke
The rate of perioperative stroke after carotid endarterectomy is 1–3%, in specialised centres <1%.
1. Clamping ischaemia of the CCA in deficient intracranial collateral circulation (circle of Willis)
- alert patient (regional anaesthesia): neurological symptoms such as unconsciousness, loss of speech, paralysis, agitation
- anaesthetised patient (general anaesthesia): e.g. non-pulsating, dark red arterial return, significant changes in EEG or SSEP (somatosensory evoked potentials) to below 50% of baseline despite adequate blood pressure, significant decrease in flow velocity in the middle cerebral artery
- Recommendation: Before clamping the CCA, administer weight-adapted intravenous heparin 3,000–5,000 IU
- -> Insert a lumen-adapted shunt from the common carotid artery into the internal carotid artery
2. Inadequate reconstruction with flow turbulence
- Caused by: residual plaque, elongations, stenotic kinking, distal step in eversion carotid endarterectomy (ECEA)
- Result: turbulent flow activates coagulation (platelet clotting)
- may lead to perioperative strokes and early occlusion
- Prevention: technically flawless reconstruction; supplementary anticoagulation with intravenous heparin 3,000–5,000 IU prevents thrombus formation
- intraoperative angiography for quality assurance
- -> operative revision/mechanical recanalisation
- -> immediate postoperative intra-arterial lysis if cerebral haemorrhage is reliably ruled out (imaging!); immediate postoperative systemic lysis is contraindicated in principle
3. Embolisation through mobilisation of plaque material during the dissection phase
- Prevention: meticulous no-touch dissection
- -> operative revision/mechanical recanalisation, possibly by endovascular technique
4. Inadequate flushing of all afferent and efferent vessels to rinse out stasis clots
- -> operative revision/mechanical recanalisation
5. Intimal clamping damage in severe sclerosis of the afferent common carotid artery
- local dissection remains undetected
- may result in thromboembolism
- -> operative revision/mechanical recanalisation