Perioperative stroke
The rate of perioperative stroke after carotid endarterectomy is 1–3%, in specialised centres < 1%.
1. Cross-clamping ischaemia of the CCA in the presence of inadequate intracranial collateral blood flow (circle of Willis)
- Awake patient (regional anaesthesia): neurological symptoms such as loss of consciousness, loss of speech, signs of paralysis, restlessness
- Anaesthetised patient (general anaesthesia): e.g. non-pulsatile dark red back-bleeding; 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 cross-clamping the CCA, administer 3000–5000 IU of heparin i.v. (weight-adapted)
- → place a shunt with matching lumen from the common carotid artery into the internal carotid artery
2. Inadequate reconstruction with turbulent flow
- Cause: residual plaque, elongation, stenotic kinking, distal step-up in eversion TEA
- Effect: turbulent flow activating coagulation (platelet clotting)
- May result in perioperative stroke and early occlusion
- Prevention: technically correct reconstruction; additional anticoagulation with 3000–5000 IU heparin i.v. prevents thrombus formation
- Intraoperative angiography for quality assurance
- → operative revision/mechanical recanalization
- → immediate postoperative intra-arterial lysis once cerebral haemorrhage has been reliably ruled out (imaging!); immediate postoperative systemic lysis is contraindicated in principle
3. Embolization through mobilization of plaque material during the dissection phase
- Prevention: meticulous dissection using the no-touch technique
- → operative revision/mechanical recanalization, possibly endovascular
4. Inadequate flushing of all run-in and run-off vessels to remove any clots from stasis
- → operative revision/mechanical recanalization
5. Clamping injury to the intima in severe sclerosis of the run-in common carotid artery
- Local dissection remaining undetected
- May result in thromboembolism
- → operative revision/mechanical recanalization