Perioperative Stroke

Laurel MooreAssociate Professor

Director, Division of NeuroanesthesiologyUniversity of Michigan

Learning Objectives• Mechanisms and timing of stroke• Procedures and comorbidities associated

with perioperative stroke• Clinical management options that may

reduce the incidence of perioperative stroke • Significance of early recognition and

treatment of stroke in the postoperative patient

Outline of Presentation

• Brief Review of Perioperative Stroke

• Preoperative risk reduction• Intraoperative risk reduction• Postoperative recognition and

possible treatment options

Why care about perioperative

stroke?

Perioperative Complication

Incidence (range)%

Myocardial infarction 0.0005-5.1

Stroke 0.1-3.0

Postoperative visual loss 0.1-0.2

Incidence of stroke by procedure

Surgical Procedure Incidence (%)

Noncardiac nonneurologic1 0.1

Total hip arthroplasty2 0.2

Vascular noncarotid3, 20 0.4-0.8

Vascular carotid27 0.9

Coronary artery bypass19, 60 2.0-3.1

Double and triple valve replacement61 9.7Aortic arch procedures with DHA4 19.2

An updated definition of stroke for the 21st century

World Health Organization 1970:“neurologic deficit of cerebrovascular cause

that persists beyond 24 hours…”

AHA/ASA 2013:“CNS infarction is defined as brain, spinal cord or retinal cell death attributable to ischemia,

based on neuropathological, neuroimaging, and/or clinical evidence of

permanent injury.”

Mechanisms of Perioperative Stroke

Ischemic

Hemorrhagic

Classification of Subtypes of Acute Ischemic Stroke

(TOAST Stroke 1993;24:35-41)

White, Circulation 2005;111:1327-1331

Watershed Infarction

Bijker, Can J Anaesth 2013;60(2):159-67

Mechanisms of Stroke

Moore, Neurologic Outcomes of Surgery and Anesthesia, Cambridge Press 2013

Comorbidities:1. Age2. TIA/stroke3. Renal disease4. Female sex5. Cardiac disease6. Hypertension7. Afib8. Tobacco

High Risk Procedures:1. CEA2. Cardiopulmonary bypass3. Open heart4. Aortic Arch

Perioperative Events:1. Antiplatelet cessation2. Statin cessation3. Afib4. Hypotension5. Dehydration6. Hypercoagulable state7. Inflammatory response

Cumulative Risk of Stroke

Mashour Anesthesiology 2011;114(6): 1289-96

High Risk ≥ 5 risk factors

Stroke incidence 1.9%, OR 21

Timing of Stroke in THR

Lalmohamed Stroke 2012;43:3225-3229

Timing of stroke in noncarotid major vascular surgery

Sharifpour, Anesth Analg 2013;116(2):424-34

Outline of Presentation• Brief Review of Stroke and Perioperative

Stroke

• Preoperative risk reduction• Intraoperative risk reduction• Postoperative recognition and possible

treatment options

1.Antiplatelet therapy2.Statin therapy

Aspirin following cardiac surgery

Mangano NEJM 2002;347:1309

Should ASA be discontinued preoperatively?

Bleeding Complications

Cerebrovascular Complications

Effects of antiplatelet therapy withdrawal

• Rebound in platelet activity with abrupt cessation

• 5% of nonoperative ischemic stroke associated with withdrawal of antiplatelet therapy

• Strokes generally occur within 2 weeks of antiplatelet cessation

“We should cease offering TURP in favour of alternative surgery

options for anticoagulated

patients”British Journal of Urology International

2011

For patients on warfarin who should receive bridging therapy?

Patients in atrial fibrillation with h/o of stroke or TIA within

6 months

Primary and Secondary Stroke

Prevention with Statins

Nassief Stroke 2008;39:1042-1048

Primary stroke prevention

Secondary stroke prevention

As regards perioperative statins:

“Prospective randomized trials…cannot

be performed anymore…because all

vascular patients should receive statin

treatment as secondary prevention of

cardiovascular disease.”AF Stalenhoef, J Vasc Surg 2009;49(4):1091

Outline of Presentation• Brief Review of Perioperative Stroke• Preoperative risk reduction

• Intraoperative risk reduction• Postoperative recognition and possible

treatment options1.Anesthetic technique2.Use of β-blockers3.Blood pressure management

Anesthetics as Neuroprotectants

Stroke reduced with Neuroaxial

Anesthesia in THR and TKR

Memtsoudis, Anesthesiology 2013;118(5):1046-1058

Lancet 2008;371(9627):1839-47

POISE Trial 2008

Association of perioperative metoprolol and perioperative stroke

Mashour Anesthesiology 2013

Stroke incidence with anemia

Metoprolol

Atenolol

Bisoprolol

Ashes, Anesthesiology 2013;119(4):777-787

The role of intraoperative hypotension in postoperative stroke

Bijker Anesthesiology 2012;116(3):658-64

A word about the dangers of the beach

chair position…

“Unusually low blood pressure will eventually result in neurological damage;

however, the threshold and duration at which an association might be found between a perioperative stroke and

hypotension have not been well investigated. Thus, the exact role of

hypotension in the etiology of perioperative stroke is still largely unknown.”

Bijker and GelbCan J Anaesth 2013;60(2):159-67

Outline of Presentation

• Brief Review of Perioperative Stroke• Preoperative risk reduction• Intraoperative risk reduction

• Postoperative recognition and possible treatment options

Recognition of postoperative stroke is frequently delayed

0-3 3-8 ≤24 ≤48 >48 0

5

10

15

20

25

30

35

40

Medical Recognition to Imaging Time

Last Known Normal to Imaging Time

# of

Str

okes

Hours post-surgery

Weightman ASA 2012 Abstract A476

“Time is Brain”

Kidwell Stroke 2004;35:2662-2665

Mechanical Thrombolysis

Suggestions for clinical management

• Stroke is more common than you think

• When possible continue anti-platelet rx

• Statins and β-blockers should continue

Suggestions for Intraoperative management

• Blood pressure goals should be assessed as % variance from baseline

• Prolonged hypotension probably bad• Normocapnia probably good• Induced hypotension for beach chair

position definitely bad• Nitrous oxide okay

Intraop management cont.

• Patients on β-blockers may be more sensitive to anemia

• Short-acting or β1-selective β-blockers when possible

• Glucose levels 80-150 mg/dL

Conclusions

• Perioperative stroke is rare but potentially devastating

• Associated co-morbidities are well-defined

• Intraoperative associations are not well-defined

• Improved recognition of postoperative stroke is necessary before acute intervention can be considered

Perioperative Care of Patients at High Risk for Stroke after Non-

Cardiac, Non-Neurologic Surgery: Guidelines from the Society for

Neuroscience in Anesthesiology and Critical Care

SNACC Task Force on Perioperative StrokeGeorge A. Mashour MD PhD, Laurel E. Moore MD, Abhijit V. Lele MD, Steven A Robicsek MD

PhD, Adrian W. Gelb MBChBhttp://www.snacc.org/