Present by Ri 張志富 Ri 戴君芙 Ri 陳婉瑜 Supervise by CR 劉治民 Endarterectomy Present by Ri 張志富 Ri 戴君芙 Ri 陳婉瑜 Supervise by CR 劉治民 2018/11/11

Carotid artery stenosis Atherosclerosis TIA & stroke Tx Antiplatelet (Aspirin) Endarterectomy Stent

Endarterectomy Indication (level I) Symptomatic, stenosis> 70 % Asymptomatic, stenosis>60% Guideline for carotid endarterectomy. A statement for healthcare professionals from a special writing group of the stroke council, American Heart Association. Stroke. 1998;

Preoperative evaluation CAD Common in P’t with carotid stenosis AMI is leading mortality Staged or combined approach CEA first: cardiac morbidity ↑ Coronary first: stroke risk ↑ Combine in unstable CAD with severe carotid stenosis Brown KR: Treatment of concomitant carotid and coronary artery disease: Decision-making regarding surgical options. J Cardiovasc Surg (Torino) 44:395–399, 2003.

General Anesthesia Unpredictable BP response Induced hypertension: 10~20% above baseline Increase brain perfusion Myocardial ischemia

Regional Anesthesia 1 Allows continuous neurologic assessment Reduced need for shunting Greater stability of blood pressure and decreased vasopressor requirements No absolute contradiction to regional anesthesia

Regional Anesthesia 2 Disadvantage No pharmacologic cerebral protection patient panic, or seizure airway inadequate in conversion

General or regional ? No differences in perioperative stroke or death rate RA: fewer nonneurological, nonfatal complications Papavasiliou AK, Magnadottir HB, Gonda T, et al: Clinical outcomes after carotid endarterectomy: Comparison of the use of regional and general anesthetics. J Neurosurg 92:291–296, 2000.

Intraoperative management of hemodynamic change Bradycardia and Hypotension Tachycardia Hypertension Cerebral intraoperative protection Monitoring for the need of carotid shunt Awake patients EEG Stump pressure Cerebral oximetry Others

Intraoperative management of hemodynamic change Bradycardia and Hypotension Carotid sinus manipulation Vagus tone↑ Myocardial infarct, neurological deficits Management local anesthetics temporary venous pacemakers intravenous atropine vasopressor

Local anesthetics 1% Lignocaine 2ml Effect of lignocaine injection in carotid sinus on baroreceptor sensitivity during carotid endarterectomy 20 patients undergoing elective CEA intraluminal stretch simulation of the carotid baroreceptors (rub test) Effect of lignocaine injection in carotid sinus on baroreceptor sensitivity during carotid endarterectomy Journal of Vascular Surgery Volume 39, Issue 6 , June 2004, Pages 1288-1294

Temporary venous pacemakers 37 balloon-assisted angioplasty and stent procedures The pacemakers captured and maintained a rhythm in 23 (62%) of the 37 procedures and prevented symptomatic bradycardia and hypotension from occurring in all of the patients. reduced the incidence of bradycardia and hypotension to only 3 (9%), as compared with the rate of 40 to 100% reported in the literature Pacemakers were set to capture a heart rate decrease below 60 beats per minute Prevention of carotid angioplasty-induced bradycardia and hypotension with temporary venous pacemakers. Neurosurgery. 2001 Oct;49(4):814-20; discussion  

Intravenous atropine treated selectively with atropine only after symptomatic bradycardia developed (nonprophylactic group) routine prophylactic atropine administration (0.5–1 mg) before balloon inflation or stent deployment (prophylactic group). Carotid angioplasty and stent-induced bradycardia and hypotension: Impact of prophylactic atropine administration and prior carotid endarterectomy. J Vasc Surg. 2005 Jun;41(6)

Intraoperative management of hemodynamic change Tachycardia Stress, pain, catecholamine release Underlying CAD Myocardial infarct Management Short-acting βblocker (eg. esmolol)

A double-blind, randomised, controlled trial of 40 patients Prevention of tachycardia with atenolol pretreatment for carotid endarterectomy under cervical plexus blockade. A double-blind, randomised, controlled trial of 40 patients 20 for placebo; 20 for 50 mg of atenolol two hours prior to surgery Tachycardia: 13/20 in the placebo group and 2/20 in the atenolol group (P < 0.01). Tachycardia (heart rate greater than 90 beats per minute for more than three minutes) Anaesth Intensive Care. 1992 May;20(2):161-4.

Intraoperative management of hemodynamic change Hypertension Stress, pain, carotid body manipulation Sympathetic tone ↑ Underlying CAD, Myocardial infarct, cerebral hemorrhage Management Nitroglycerin Sodium nitroprusside Crossclamping後血壓稍微上昇以便增加collateral circulation是可接受的 不過SBP>160要治療 Unclamping後HTN也要治療 Crossclamping後血壓會稍微上升以便增加collateral circulation是可接受的 但Hypertension: SBP>160

Cerebral intraoperative protection Carotid shunt Blood bypass from common to internal carotid artery Complication: Intimal flap arterial dissection Plaque emboli or air embolism

Cerebral intraoperative protection Monitoring Awake patients Under regional anesthesia Eye movement, speech, grasping, consciousness

Cerebral intraoperative protection Monitoring EEG Theta and delta waves or disorganized rhythm Routine use of EEG was associated with apparent complete elimination of intraoperative strokes and less than 1% risk of perioperative strokes. Carotid endarterectomy with routine electroencephalography and selective shunting: Influence of contralateral internal carotid artery occlusion and utility in prevention of perioperative strokes. J Vasc Surg. 2002 Jun;35(6):1114-22 Comparison of simultaneous electroencephalographic and mental status monitoring during carotid endarterectomy with regional anesthesia Journal of Vascular Surgery Volume 28, Issue 6 , December 1998, Pages 1014-1023

Cerebral intraoperative protection Monitoring Stump pressure Circle of Willis ↔ ICA Threshold: 30-50 mmHg Correlation of carotid artery stump pressure and neurologic changes during 474 carotid endarterectomies performed in awake patients. Using 40 mm Hg systolic as a threshold, the need for shunting (15%) and the false-negative rate (1.0%) for SP in our series were equivalent to the results of EEG monitoring during CEA reported in the literature. J Vasc Surg. 2005 Oct;42(4):684-9.

Cerebral intraoperative protection Monitoring Cerebral oximetry Regional cerebral oxygen saturation Could not identify a threshold that can be used alone to predict the need for shunt placement After San Raffaele Hospital Ethical Committee Approval and written informed consent were obtained, 50 ASA physical status II and III adults, aged 51 to 90 years and undergoing elective CEA with regional anesthesia, were prospectively studied. A clinical evaluation of near-infrared cerebral oximetry in the awake patient to monitor cerebral perfusion during carotid endarterectomy. J Clin Anesth. 2005 Sep;17(6):426-30. P=0.01

Cerebral intraoperative protection Others Arterial blood pressure Preoperative level or slightly higher Normocapnia Hypothermia Volatile anesthetics and barbiturates Avoid nitrous oxide: ↑postoperative myocardial ischemia Induction drugs Sodium thiopental Propofol Etomidate

SSEP The response of the sensory cortex Able to detect subcortical sensory pathway ischemia Decreased regional cerebral blood flow (< 12 mL/100 g of brain tissue per minute) No specific physiologic marker influenced amplitude Not been definitively established Canadian Journal of Anesthesia 51:937-941 (2004)

Transcranial Doppler (TCD) Continuous measurement of blood flow Detection of microembolic events Peri-op: shunt function, malfunction, and incidence of emboli during shunt insertion Post-op: early postoperative embolization, hyperperfusion syndrome Technical difficulties Outcome has not been reported Annals of Vascular Surgery Inc. 2005,11 January

Postoperative Considerations Postoperative stroke Postoperative hypertension & hypotension Hyperperfusion syndrome Others

Postoperative stroke Cause Plaque emboli Platelet aggregates Poor cerebral protection Relative hypotension

Evaluation and treatment Recovery room or intraoperative ultrasound The optimal time to heparinize ? Percutaneous transluminal carotid angioplasty with stenting Thrombolytic therapy

Postoperative hypertension Poorly controlled preoperative hypertension Surgical denervation of the carotid sinus baroreceptors General anesthesia > Regional anesthesia Neurologic and cardiac complications

Postoperative hypotension As frequently as hypertension Carotid sinus baroreceptor hypersensitivity or reactivation Regional anesthesia > General anesthesia Myocardial and cerebral ischemia Fluids and vasopressors

Hyperperfusion syndrome Abrupt increase in blood flow with loss of autoregulation Occurs several days after sugery Moderate (20 to 44 %) increases in ipsilateral cerebral blood flow (by PWI) Absence of increases in middle cerebral artery flow velocity (by TCD)

Risk Factors High-grade (>80%) carotid stenosis Recent cerebral infarction Reduced CBF or cerebral vasoreactivity Severe postoperative hypertension

Symptoms and Signs Headache Focal motor seizures Focal neuralogic sign Intracerebral hemorrhage Brain edema

Treatment Strict control of postoperative hypertension (SBP<150mmHg) Intravenous labetalol, nitroprusside, and nitroglycerin Most postoperative BP lability resolves in the first 24 hours

Others Nerve injury Wound hematoma Respiratory distress Infection Parotitis

Prognosis Predictors of mortality Age Male sex Diabetes mellitus Systemic hypertension Cigarette smoking

References Miller: Miller's Anesthesia, 6th ed Anesthesiology Clinics of North America Volume 22 • Number 2 • June 2004 James P Greelish, Emile R Mohler, III, Ronald M Fairman, for carotid endarterectomy (Cochrane review). The Cochrane Library. Issue 2 Oxford: Update Software; 2006.

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