Complications - Open TEA of the left carotid bifurcation with patch angioplasty and temporary intraluminal shunt

Perioperative Stroke

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

1. Clamping Ischemia of the CCA with Insufficient Intracranial Collateral Supply (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 backflow, significant changes in EEG or SSEP (somatosensory evoked potentials) to below 50 % of baseline despite adequate blood pressure, significant drop in flow velocity in the middle cerebral artery
• Recommendation: Before clamping the CCA, weight-adapted 3000 – 5000 IU heparin i.v.
• → Insertion of a lumen-adapted shunt from the common carotid artery into the internal carotid artery

2. Insufficient Reconstruction with Flow Turbulences

• Cause: remaining plaque parts, elongations, kinking stenoses, distal step in eversion TEA
• Consequence: turbulent flow leads to coagulation activation (platelet clotting)
• can result in perioperative strokes and early occlusions
• Prophylaxis: technically flawless reconstruction, additional anticoagulation with 3000 –5000 IU heparin i.v. prevents thrombus formation
• intraoperative angiography for quality control
• → surgical revision/mechanical recanalization
• → immediate postoperative intra-arterial lysis provided cerebral hemorrhage is reliably excluded (imaging!); systemic lysis immediately postoperatively is generally contraindicated

3. Embolization due to Mobilization of Plaque Material during the Preparation Phase

• Prophylaxis: subtle preparation in no-touch technique
• → surgical revision/mechanical recanalization, if necessary endovascular

4. Inadequate Flushing of All Inflowing and Outflowing Vessels to Flush Out Stasis Clots

• → surgical revision/mechanical recanalization

5. Clamp Damage to the Intima in Severe Sclerosis of the Supplying Common Carotid Artery

• local dissection remains unrecognized
• can lead to thromboembolisms
• → surgical revision/mechanical recanalization

Hematomas/Secondary Bleeding

• acc. to NASCET study in 7.1% of all carotid endarterectomies, of which 3.9% mild (no revision), 3% moderate (revision) and 0.3% as the most severe complication with permanent deficit or fatal outcome
• hypertensive blood pressure situations in the recovery phase and early postoperatively increase the risk of secondary bleeding → intensive monitoring for at least 8 – 12 hours
• airway obstruction makes intubation difficult or impossible, therefore rapid hematoma evacuation (if necessary at the bedside with provisional digital hemostasis, then intubation and surgical revision)
• Warning signs: inspiratory stridor, lump in throat or nasal speech, swallowing disorders

Wound Infection

• Incidence approx. 1%
• deep infections < 0.5%
• Treatment of early and late superficial/deep infections of the neck soft tissues follows usual standards
• incise and drain putrid infections early, targeted antibiotic therapy according to antibiogram
• Grade III according to Szilagyi: prosthetic material must be replaced by autologous (body's own vein)

Classification of Vascular Prosthesis Infections according to Szilagyi*

*Szilagyi DE, Smith RF, Elliott JP, Vrandecic MP. "Infection in arterial reconstruction with synthetic grafts." Ann Surg, 1972, 176 pp. 321-333.

Nerve Lesions

1. Cutaneous Nerves

• depending on literature, injury rates for cutaneous nerves immediately postoperatively up to 69%, permanent up to 26%
• sensory regeneration possible, may take months
• Regeneration prognosis for protopathic sensitivity (pain and temperature sensation) more favorable, as the fibers end blindly in the subcutis
• persistent neuropathic pain after cutaneous nerve lesion very rare

2. Cranial Nerves

• Incidence approx. 5 – 15%
• mostly temporary or frequently reversible within one year
• Treatment: Corticosteroids

Injury to Neural Structures in the Access Area of the Carotid Artery

Avoidance of Neural Damage

• secure mastery of the anatomy
• careful preparation to identify and display neural structures in the surgical field
• anticipate atypical anatomical variants and prepare them particularly carefully
• no coagulation of bleedings from the perineurium
• avoid compression of nerves by hooks and retractors

Hyperperfusion Syndrome

• rare neurological complication after TEA or stent therapy of the ICA (incidence: 0.4 – 3%)
• Occurrence on the 5th – 7th day postop. with peak frequency on the 5th day
• typical triad: severe headaches, seizures, intracerebral hemorrhage
• intracranial hemorrhage in 0.8 – 1.8%, mortality in 40 – 60% (!)
• Pathophysiology: Loss of autoregulation of intracerebral blood flow
• Consequences:
  • stenosis-related primary hypoperfusion leads to reactive maximal vasodilation of the downstream intracerebral vessels
  • after restoration of normal perfusion by TEA or stent: transmural edematous transudation due to "capillary leaks" →  brain edema, possibly also intracranial hemorrhage

• Risk factors:  
  • pronounced postoperative hypertension
  • high-grade contralateral stenosis or occlusion of the ICA
  • occurred ischemia as well as previous contralateral carotid TEA within the last 3 months
  • also: significant correlation between clamping time and postoperatively measured hyperperfusion on the ipsilateral side

• Prophylaxis:
  • Avoid postoperative blood pressure peaks, requires appropriate monitoring

• Treatment:
  • aggressive blood pressure reduction
  • Anticonvulsants
  • anti-edematous treatment of brain edema
  • Intubation/ventilation

Recurrent Stenoses

• Incidence: approx. 1% per year
• Causes:
  • Progression of atherosclerosis
  • technical errors
  • Surgical technique:  Eversion TEA, TEA + patch, stent PTA;  patch type (vein, synthetic, homologous patch material)
• Treatment:
  • Indication: symptomatic or ICA stenosis > 80%
  • surgical; endovascular: in surgical restenosis, stent PTA possible

Pseudoaneurysm

• rare after TEA, usually years after use of synthetic materials
• Treatment: Vein patch, vein interposition