Complications - Dolichoarteriopathy – Severe kinking with luminal narrowing type I/III of the right internal carotid artery

Perioperative stroke

The rate of perioperative strokes after carotid endarterectomy is 1%–3%, in specialized centers <1%. 

1. Clamping ischemia of CCA in deficient intracranial collateral circulation (circle of Willis)

• alert patient (regional anesthesia): neurologic symptoms such as unconsciousness, loss of speech, paralysis, agitation
• sleeping patient (general anesthesia):  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 velocity in the middle cerebral artery
• Recommendation: Before clamping the CCA administer intravenous heparin 3,000 IU - 5,000 IU (weight-adapted)
• -> Insert a lumen-adapted shunt from the common carotid into the internal carotid artery

2. Inadequate reconstruction with flow turbulence

• Caused by: Remaining 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 IU–5,000 IU prevents thrombus formation
• Intraoperative angiography for quality assurance
• -> operative revision/mechanical recanalization
• -> Immediate postoperative intraarterial lysis if cerebral bleeding is reliably ruled out (imaging!); immediate postoperative systemic lysis is contraindicated

3. Embolization by mobilizing plaque material during the dissection phase

• Prevention: subtle no-touch dissection
• -> operative revision/mechanical recanalization,  possibly by endovascular technique

4. Inadequate flushing of all afferent and efferent vessels to rinse out stasis clots

• -> operative revision/mechanical recanalization

5. Intimal clamping damage in severe sclerosis of the afferent common carotid artery

• Local dissection stays undetected
• May result  in thromboembolism
• -> operative revision/mechanical recanalization

Hematoma/secondary bleeding

• According to NASCET trial in 7.1% of all carotid endarterectomies, with 3.9% mild (no revision), 3% moderate (revision) and 0.3% as the most severe complication with lasting deficit or fatal outcome
• hypertensive blood pressure situations during the recovery and early postoperative period increase the risk of secondary bleeding -> Intense monitoring for at least 8 - 12 hours
• Intubation complicated or impossible due to airway obstruction; therefore, immediate hematoma relief (if necessary, at point-of-care with temporary manual hemostasis, then intubation and revision surgery).
• Warning signs: Inspiratory stridor, dumpy or nasal speech, dysphagia
• Incidence about 1%
• Deep infections <0.5%
• Treatment of early and late superficial/deep infections of the soft tissues of the neck follows the usual standards
• Open and drain putrid infections early, targeted antibiosis according to antibiogram

Wound infection

Nerve lesions

1. Skin nerves

• According to literature, injury rates for skin nerves in the immediate postoperative phase up to 69% and permanently up to 26%
• Sensory regeneration possibly, but may take months
• Regeneration prognosis for protopathic sensitivity (pain and temperature sensation) more favorable, since these fibers terminate blindly in the subcutis
• Persistent neuropathic pain after skin nerve lesion is quite rare

2. Cranial nerves

• Incidence about 5%–15%
• Mostly temporary or often reversible within one year
• Treatment: Corticosteroids

Nervous injuries in the region of approach to the carotid artery

Preventing nerve injuries

• Confident mastery of the anatomy
• Identification and exposure of nerve structures in the surgical field by careful dissection.
• Anticipate atypical anatomical variants and dissect them meticulously
• Do not coagulate perineural bleeders
• Avoid nerve injury from retractors
• Rare neurologic complication after CEA or ICA stenting (incidence: 0.4%–3%), also resulting from clamping/declamping
• Presents on postoperative day 5–7, peaking on day 5
• Typical triad: Severe headaches, seizures, intracranial bleeding
• Intracranial bleeding of 0.8%–1.8%, mortality of 40%–60 % (!)
• Pathophysiology: Loss of intracerebral blood flow autoregulation
• Outcome:

Hyperperfusion syndrome

        → Stenosis-related primary hypoperfusion leads to reactive maximum vasodilation of intracerebral vessels downstream

        → After normal perfusion has been restored by CEA or stent: transmural edematous transudation due to capillary leaks -> cerebral edema, possibly also intracranial bleeding

• Risk factors:  

         ◊ Marked postoperative hypertension

         ◊ High-grade contralateral stenosis or occlusion of the ICA

         ◊ History of ischemia and contralateral CEA within the last 3 months

         ◊ Also: Significant correlation between the clamp-time and postoperatively measured ipsilateral hyperperfusion

• Prevention:

         ◊ Avoiding postoperative blood pressure spikes, requires appropriate monitoring

• Treatment:

         ◊ Marked lowering of blood pressure

         ◊ Anticonvulsants

         ◊ Antiedematous treatment of brain edema

         ◊ Intubation/mechanical ventilation

Recurrent stenosis

• Incidence about 1% per year
• Causes:

        ◊ Progressive arteriosclerosis

        ◊ Surgical technique:  Eversion CEA, CEA + patch, stent-PTA; patch type (vein, plastic, homologous patch material)

• Treatment:

         ◊ Indication: Symptomatic or ICA stenosis >80%

         ◊ Surgical; endovascular: In surgical recurrent stenosis stent-PTA possible

Pseudoaneurysm

• Rare after CEA; usually years after implantation of plastic materials
• Treatment: Vein patch