Perioperative stroke
The rate of perioperative stroke after carotid endarterectomy is 1-3%, in specialized centers <1%.
1. CCA cross-clamping ischemia in the presence of inadequate intracranial collateral blood flow (circle of Willis)
- Awake patient (regional anesthesia): neurological symptoms such as unconsciousness, loss of speech, paralysis, restlessness
- Sleeping patient (general anesthesia): 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 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 revascularization with turbulent flow
- Cause: residual plaque, elongation, stenotic kinking, endpoint edge/step-up in eversion TEA
- Effect: turbulent flow activating coagulation (platelet clotting)
- May result in perioperative stroke and early occlusion
- Prevention: technically correct repair, additional anticoagulation with 3000 -5000 IU heparin i.v. prevents thrombus formation
- Intraoperative angiography for quality assurance
- → operative revision/ mechanical recanalization
- → Immediate postoperative intraarterial lysis once cerebral hemorrhage has been reliably ruled out (imaging!); immediate postoperative systemic lysis is contraindicated in principle
3. Mobilization of plaque material during dissection and embolization
- Prevention: subtle dissection in no-touch technique
- → operative revision/ mechanical recanalization, possibly endovascular approach
4. Inadequate flushing of all run-in and run-off vessels to remove any clots from stasis
- → operative revision/ mechanical recanalization
5. Intimal cross-clamping injury in severe sclerosis of the common carotid artery run-in
- Local dissection remaining undetected
- May result in thromboembolism
- → operative revision/ mechanical recanalization