Perioperative stroke
The perioperative stroke rate after carotid endarterectomy is 1–3%, and <1% in specialised centres.
1. Clamping ischaemia of the CCA in insufficient intracranial collateral circulation (circle of Willis)
- alert patient (regional anaesthesia): neurological symptoms such as loss of consciousness, loss of speech, paralysis, agitation
- anaesthetised patient (general anaesthesia): e.g. non-pulsatile, dark red backflow, 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 heparin 3,000–5,000 IU i.v.
- -> Insert a lumen-adapted shunt from the common carotid into the internal carotid artery
2. Inadequate reconstruction with flow turbulence
- Caused by: residual plaque, elongations, stenotic kinking, distal step in eversion CEA
- Result: turbulent flow activates coagulation (platelet clotting)
- may result in perioperative strokes and early occlusions
- Prevention: technically flawless reconstruction; supplementary anticoagulation with heparin 3,000–5,000 IU i.v. prevents thrombus formation
- Intraoperative angiography for quality assurance
- -> operative revision/mechanical recanalisation
- -> immediate postoperative intra-arterial lysis provided cerebral haemorrhage has been reliably ruled out (imaging!); immediate postoperative systemic lysis is in principle contraindicated
3. Embolisation through mobilisation of plaque material during the dissection phase
- Prevention: meticulous dissection using a no-touch technique
- -> 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