350 carotid endarterectomy
TRANSCRIPT
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