Carotid endarterectomy

350Michael J. Link

Kelly D. FlemmingFredric B. Meyer

Carotid endarterectomy• North American Symptomatic Carotid Endarterectomy Trial (NASCET)• European Carotid Surgery Trial (ECST)

Preoperative Evaluation

Symptomatic Patients• TIA or minor stroke of the anterior

circulation• Routine laboratory evaluation,EKG,

CXR, CT NC• Screening : ultrasonography of

the carotid arteries• Confirm : MRA• CTA

Asymptomatic Patients• Screening is not recommend• Based on age, male sex, hypertension,

tobacco abuse, peripheral vascular disease

Indications Based on Randomized Controlled Trials:Symptomatic Patients

NASCETNorth American Symptomatic Carotid Endarterectomy Trial

• Jan 1988 – Feb 1991• 659 pt, 50 clinical center• 50 CEA procedures/ 2 Yrs / mortality

rate < 6 %• Within 120 days, < 80 Yrs, ICA stenosis

30 – 90 %• 1.Aspirin, 1300 mg/day, and other

stroke reduction therapy as : 331• 2.Surgery : CEA, 328

ECST

European Carotid Surgery Trial

• 12 European country, 1998• 4018 pt,97 center• Within 6 Mo• 1.Surgery 1807• 2.Medical 1211

Indications Based on Randomized Controlled Trials:Symptomatic Patients

NASCETNorth American Symptomatic Carotid Endarterectomy Trial• Greastest point narrowing / Beyond

the bulb• Perioperative stroke : 5.8%

ECSTEuropean Carotid Surgery Trial• Greastest point narrowing / estimate

original diameter• Combined outcome surgical event,

ipsilateral major ischemic strokes• Perioperative stroke : 7.0%

Indications Based on Randomized Controlled Trials:Symptomatic Patients

• Highly significant benefit in patients with high-grade (70% to 99%) stenosis• Moderate stenosis(50% to 69 %) group also revealed a statistical

benefit• No benefit , stenosis less than 50 %• Surgery within 2 weeks of the last symptom improved outcomes

relative to later surgery (especially in women)• No increased operative risk when operating within 2 weeks of a

nondisabling hemispheric stroke

Summary indication• Recently symptomatic carotid stenosis (preferably within 2 weeks of

the last symptom) of 70% to 99% in patients with a life expectancy of at least 5 years if the expected perioperative risk is expected to be less than 6%.

• Recently symptomatic carotid stenosis of 50% to 69% with the same caveats as above, except that women were not shown to benefit from CEA and should probably be managed medically.

Summary indication• Asymptomatic patients between the ages of 40 and 79 years with

greater than 60% stenosis and no significant comorbid conditions that might increase their perioperative risk or result in a life expectancy of less than 5 years. The overall perioperative risk should be less than 3%• The benefit to women is controversial, and careful consideration has

to be given to recommending prophylactic CEA for female patients.

Technique• Thor Sundt, Jr., M.D.• The department of Neurologic Surgery at the Mayo Clinic• More than 3000 CEAs• Trained generations of residents in this technique

Positioning and Exposure

• GA• EEG• Supine position• Head turn to opposite site, extension• Curvilinear incision• 1 cm below the tip of the mastoid, curves 1 cm below the angle of the mandible, and ends 1 cm above the sternoclavicular joint• Skin, platysma, cervical fascia

Positioning and Exposure• Not violate the parotid fascia• Dissected anterior border of SCM from cervical fascia• Can palpate carotid system• Open cervical fascia to expose common carotid artery• Omohyoid m. : inferior extent• Posterior belly of the digastric m. : superior extent

Positioning and Exposure• Carotid bifurcation, ECA, ICA• Common facial vein, running transversely : double ligate and divided• Hypoglosaal nerve : superficial to the ECA and ICA, just below the digastric muscle• Descendens hypoglossi : can be sacrificed• Vagus N. or Descendens hypoglossi : deep to carotid system between

the carotid and the IJV• Superior laryngeal n. : dysphagia post-op

Positioning and Exposure• Standard fish hooks• Soft vessel loops : CCA, ECA(2 cm from it origin), superior thyroid artery• Great care when taking bifurcation and the proximal ICA : not

dislodge emboli

Exposure for a High Bifurcation or Plaque

• Above the C3 level, a plaque that extends high up the ICA• More cephalad exposure• Curved forward and inferior in the postauricular sulcus while skirting

the earlobe, and then ascend in the pretragal skin crease.• Elevating posterior border of parotid gland• Posterior belly of digastric muscle• Hypoglossal n. deep and inferior• Stylohyiod muscle • Deeper stylomandibular ligament

Endarterectomy

• Adequate distal exposure of the cervical ICA : crucial successful completion of procedure• Heparin 5000 IU IV : doubling of the activated clotting time• Occlude tension on superior thyroid arteryECA• Elevated SBP to 160-180 mmHG• Fogarty clamp on proximal CCA( soft portion) : one click• Curved 12 mm temporary sugita aneurysm clip place on distal ICA• Blade no.11 for arteriotomy at mid CCA

Endarterectomy

• Endarterectomy at carotid bifurcation• Small spatula

• Pott’s scissors• Until normal intima seen• Open temporary clip to observe back

flow

Endarterectomy

• Break point• Carry proximal to CCA

• No natural break point proximally• Made with Pott’s scissors

Endarterectomy

• Circumferentially dissected• Vascular tape on ECA can be loosed• ECA evert to allow more distal

dissection

• Once the plaque starts to thin out• Grasp and removed

Shunt Placement

• Change in monitor 16-channel EEG ipsilateral to the occluded ICA• Reliable indicator of ischemia• Faster frequency of > 4 Hz by > 50%• Increase in the amplitude of delta activity by 50%

• Internal Sundt shunt• Proximal on the artery• Distal on the artery• EEG is not improve : distal emboli or occlusion• Check backflow : if no pass Fogarty balloon catheter to see whether a clot

Patch Closure of the Arteriotomy

• Knitt Dacron patch• Distal end trim to V• Double-armed 5-0 Prolene suture• Apex of patch and apex of arteriotomy• Runnig stich• 1 mm deep and 1 mm distal to previous stich• Two step

Primary Closure of the Arteriotomy

• < 1% encounter : patch angioplasty not necessary• 6-0 Prolene• First : Distal to proximal ¾• Second : Proximal to distal

Restoration of flow• Before typing last suture• Lower SBP to 130-150 mmHg• Backbled ICA 8-10 s• Fogary clamp on CCA : temporary open• Suture last stich• Relax tape on ECA and superior thyroid artery

Restoration of flow• Remove aneurysm clip• Typical occlusion time 30-60 min• Very common for significant bleeding to arise from suture : surgeon’s finger tip or irrigation with warm saline• Gel foam• Doppler US • ICA : low-resistance sound• ECA : brisk,high-resistance sound

Closure• 10 French Jackson-Pratt drain• Platysma : interrupted 2-0 vicryl• Dermis : interrupted 3-0 vicryl• Skin : running 4-0 vicryl

Postoperative care• ASA(325) at night• Off drain in the morning

Management of complication• Strict BP to avoid hyperperfusion injury• Sustain mABP raise 15 mmHG : RX with beta-blocker or vasodilator• Post-op neurological decifit : CT brain NC• If CT normal : Cerebral angiography,look for endarterctomy site• Endarterectomy site normal and there is evidence of distal emboli :

heparin anticoagulant• Acute occlusion of ICA : return to operating room• Postoperative neck hematoma