Difference between revisions of "Craniotomy for intracranial vascular malformations"

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* The Spetzler-Martin AVM grading system estimates morbidity and mortality of surgery<ref>{{Cite journal|last=Spetzler|first=R. F.|last2=Martin|first2=N. A.|date=1986-10|title=A proposed grading system for arteriovenous malformations|url=https://pubmed.ncbi.nlm.nih.gov/3760956|journal=Journal of Neurosurgery|volume=65|issue=4|pages=476–483|doi=10.3171/jns.1986.65.4.0476|issn=0022-3085|pmid=3760956}}</ref>
* The Spetzler-Martin AVM grading system estimates morbidity and mortality of surgery<ref>{{Cite journal|last=Spetzler|first=R. F.|last2=Martin|first2=N. A.|date=1986-10|title=A proposed grading system for arteriovenous malformations|url=https://pubmed.ncbi.nlm.nih.gov/3760956|journal=Journal of Neurosurgery|volume=65|issue=4|pages=476–483|doi=10.3171/jns.1986.65.4.0476|issn=0022-3085|pmid=3760956}}</ref>
<calculatormodule id="neuro" />
<calculatoroptions patientInputInline="true" />
<calculation id="avmSpetzlerMartinGradeRisk">Spetzler-Martin AVM grading scale</calculation>
<calculation id="avmSupplementalGradeRisk">Supplemental AVM grading scale</calculation>


=== Surgical procedure ===
=== Surgical procedure ===
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|-
|-
|Airway
|Airway
|
|If acute, consider RSI
|-
|-
|Neurologic
| Neurologic  
|Neurologic symptoms and mental status, signs and symptoms of elevated ICP, seizures  
|Unruptured vs. ruptured important for risk stratification. Neurologic symptoms and mental status, signs and symptoms of elevated ICP, seizures  
|-
|-
|Cardiovascular
|Cardiovascular
|Commonly associated with hypertension as well as other cardiac abnormalities including ischemia, arrhythmias, left ventricular dysfunction, and pulmonary edema.
| If acutely ruptured, can be associated with hypertension as well as other cardiac abnormalities including ischemia, arrhythmias, left ventricular dysfunction, and pulmonary edema.
|-
|Pulmonary
|
|-
|Gastrointestinal
|
|-
|-
|Hematologic
|Hematologic
|Anemia
|Anemia
|-
|Renal
|
|-
|Endocrine
|
|-
|Other
|
|}
|}


=== Labs and studies<!-- Describe any important labs or studies. Include reasoning to justify the study and/or interpretation of results in the context of this procedure. If none, this section may be removed. --> ===
===Labs and studies<!-- Describe any important labs or studies. Include reasoning to justify the study and/or interpretation of results in the context of this procedure. If none, this section may be removed. -->===


=== Operating room setup<!-- Describe any unique aspects of operating room preparation. Avoid excessively granular information. Use drug classes instead of specific drugs when appropriate. If none, this section may be removed. --> ===
* BMP
*CBC
*Coags
*Type and screen
* Brain MRI


=== Patient preparation and premedication<!-- Describe any unique considerations for patient preparation and premedication. If none, this section may be removed. --> ===
=== Operating room setup<!-- Describe any unique aspects of operating room preparation. Avoid excessively granular information. Use drug classes instead of specific drugs when appropriate. If none, this section may be removed. -->===
*Rapidly titratable vasoconstrictors and vasodilators in bolus syringes and infusions to acutely manage blood pressure
**Phenylephrine or norepinephrine
**Clevidipine, nitroprusside, or nitroglycerine. Nicardipine less desirable intraoperatively given longer pharmacokinetics.
*Adenosine (at least 1 mg/kg rapidly available)
*Osmotic agents (mannitol and/or hypertonic saline)
* Crossmatched blood should be available
===Patient preparation and premedication<!-- Describe any unique considerations for patient preparation and premedication. If none, this section may be removed. -->===
*Midazolam often beneficial to prevent anxiety-induced hypertension
*Consider aprepitant 40 mg PO for additional PONV prophylaxis
*See [[Craniotomy for intracranial aneurysm#Hemodynamic management|hemodynamic management]] section below
===Regional and neuraxial techniques<!-- Describe any potential regional and/or neuraxial techniques which may be used for this case. If none, this section may be removed. -->===


=== Regional and neuraxial techniques<!-- Describe any potential regional and/or neuraxial techniques which may be used for this case. If none, this section may be removed. --> ===
*Consider postoperative scalp block for analgesia


== Intraoperative management ==
==Intraoperative management==


=== Overall Goals ===
=== Overall Goals===
Goals are to provide a stable hemodynamic anesthetic along with reducing/normalizing the ICP and maintaining adequate CPP (at least 70 mmHg) to prevent cerebral ischemia from brain retraction, brain swelling and vasospasm. Perioperative AVM rupture from hypertension is possible, but rare. However, in case of a coexisting aneurysm, hypertension must be avoided.
Goals are to provide a stable hemodynamic anesthetic along with reducing/normalizing the ICP and maintaining adequate CPP (at least 60-70 mmHg) to prevent cerebral ischemia from brain retraction, brain swelling and vasospasm. Perioperative AVM rupture from hypertension is possible, but rare. However, in case of a coexisting aneurysm, hypertension must be avoided.


=== Monitoring and access<!-- List and/or describe monitors and access typically needed for this case. Please describe rationale for any special monitors or access. --> ===
===Monitoring and access<!-- List and/or describe monitors and access typically needed for this case. Please describe rationale for any special monitors or access. -->===
Standard ASA
*Standard ASA
*5-lead ECG
*Core temperature
**Consider bladder temperature monitoring if using mild hypothermia
*Arterial line
*2 large bore IVs
*Consider central access
**Rapid administration of vasoactives, adenosine
**Peripheral vasoconstriction may limit drug delivery if using hypothermia
**CVP monitoring, though added value is unclear
* Evoked potential monitoring
*EEG monitoring
*External ventricular drain may be useful for ICP monitoring and management if ruptured
===Hemodynamic management===
If ICP monitoring is available, maintain cerebral perfusion pressure near 60 mmHg.
====Unruptured AVMs====
*Preoperatively: Maintain blood pressure at or below patient's baseline.
*Intraoperatively: Target MAP 60-80 mmHg.**If hypertensive at baseline, baseline blood pressure may pose rupture risk once dura is opened and/or aneurysm is exposed (since transmural pressure gradient will increase)
====Ruptured AVMs====
*Preoperatively:
**Passive hypertension may represent beneficial reflex to maintain cerebral perfusion pressure in the setting of increased intracranial pressure, and should probably not be treated.
**Hypertension due to noxious stimuli (i.e. pain, anxiety, disinhibition) should be avoided and appropriately treated depending on etiology (e.g. analgesics, anxiolytic, sedation).
* Intraoperatively: Target MAP 60-80 mmHg.
===Induction and airway management<!-- Describe the important considerations and general approach to the induction of anesthesia and how the airway is typically managed for this case. -->===


5-lead ECG
*Hemodynamically stable induction of general anesthesia and intubation is critical
**Fentanyl, propofol, rocuronium, and +/- vasoactive agents to avoid hypo- and hypertension.
*Moderate hyperventilation (PaCO2 30 mmHg) may be useful if concern for elevated ICP


Core temp
=== Maintenance and surgical considerations<!-- Describe the important considerations and general approach to the maintenance of anesthesia, including potential complications. Be sure to include any steps to the surgical procedure that have anesthetic implications. -->===
*Brain relaxation (hyperventilation, osmotic agents, CSF removal) should be used with caution in ruptured aneurysms
** Decreased ICP can increase transmural pressure and increase risk of re-rupture/worsen bleeding
**Risk/benefit should be discussed with surgeons
*Antibiotics (cefazolin 2-3 g)
*Dexamethasone (8-10 mg)
*± Antiepileptics (levetiracetam 1 g)
==== Anesthetic maintenance====
Anesthesia can be maintained safely using several techniques, and should be guided by provider experience, institutional practices, and unique patient considerations
*Many centers recommend the use of total intravenous anesthesia with propofol and remifentanil
**Cerebral vasocontriction from propofol may be desirable
**Limited interference with evoked potential monitoring
**Antiemetic effect of propofol desirable
**EEG monitoring essential to ensure drug delivery and allow dose titration
*Some centers use volatile anesthetics and/or nitrous oxide
**Inhaled anesthetic somewhat mitigates risk of line infiltration and patient emergence/movement while in pinned frame
**≤0.5 MAC of volatile anesthetic will limit cerebral vasodilation, decoupling of autoregulation and interference with evoked potential monitoring
**Consider risk of nitrous oxide expansion of pneumocephalus
*A combination of techniques can be used to leverage the benefits of each approach. For example:
**Sevoflurane 0.5 MAC
**Propofol 50-75 mcg/kg/min
**Remifentanil 0.1-0.2 mcg/kg/min
**Anesthetic and analgesic agents titrated using EEG
====Temporary clipping====
In some circumstances, surgeons may place a temporary clip proximal to the aneurysm to occlude flow and allow dissection and exposure without rupture. However, this can create focal ischemia distal to the clip/aneurysm. To minimize the risk of worsened neurologic outcomes, consider:
*Minimize temporary clip time
*Increase MAP (~90 mmHg) after clip placement to facilitate collateral perfusion
*Evoked potential monitoring to provide realtime feedback to surgeons
*Minimal evidence to support neuroprotective measures<ref>{{Cite journal|last=Hindman|first=Bradley J.|last2=Bayman|first2=Emine O.|last3=Pfisterer|first3=Wolfgang K.|last4=Torner|first4=James C.|last5=Todd|first5=Michael M.|last6=IHAST Investigators|date=2010-01|title=No association between intraoperative hypothermia or supplemental protective drug and neurologic outcomes in patients undergoing temporary clipping during cerebral aneurysm surgery: findings from the Intraoperative Hypothermia for Aneurysm Surgery Trial|url=https://pubmed.ncbi.nlm.nih.gov/19952722/|journal=Anesthesiology|volume=112|issue=1|pages=86–101|doi=10.1097/ALN.0b013e3181c5e28f|issn=1528-1175|pmid=19952722}}</ref>
**Some providers still use induce burst suppression with a propofol bolus (~1 mg/kg) immediately prior to temporary clip placement due to the relative ease of rapid induction with minimal risk to hemodynamic stability
***Concurrent bolus of vasoconstrictor often required to maintain stable MAP
**Hypothermia not associated with improved outcomes during temporary clipping
===Potential complications<!--List and/or describe any potential postoperative complications for this case.-->===
====AVM rupture====
Intraoperative AVM rupture can happen at any time until the malformation is resected. AVM rupture is a true emergency that requires rapid intervention.


UOP
If the AVM is exposed:<ref>{{Cite web|last=Laurel E Moore, Magnus K Teig, Vijaykumar Tarnal|date=4/1/2022|title=Anesthesia for intracranial neurovascular procedures in adults|url=https://www.uptodate.com/contents/anesthesia-for-intracranial-neurovascular-procedures-in-adults|url-status=live}}</ref>
 
*Improve surgical visualization by decreasing/stopping bleeding rate to allow clip placement
Arterial line
**Discuss with surgeons
 
**Typically start with induced hypotension (MAP 50-60) using a short acting agent (e.g. clevidipine or esmolol)
2-3 large bore IVs
**If insufficient, consider inducing temporary flow arrest (asystole) using adenosine 0.3-0.6 mg/kg<ref>{{Cite journal|last=Desai|first=Virendra R.|last2=Rosas|first2=Alejandro L.|last3=Britz|first3=Gavin W.|date=2017|title=Adenosine to facilitate the clipping of cerebral aneurysms: literature review|url=https://pubmed.ncbi.nlm.nih.gov/29507781/|journal=Stroke and Vascular Neurology|volume=2|issue=4|pages=204–209|doi=10.1136/svn-2017-000082|issn=2059-8696|pmc=5829927|pmid=29507781}}</ref>
 
***If ineffective arrest achieved, double adenosine dose
Central line if poor peripherals access
***Doses as high as 2 mg/kg have been reported as necessary
 
*Reduce CMRO2 with propofol 0.5-1 mg/kg bolus, increase infusion rate
Neuromonitoring
*Resuscitate as indicated with IVF or blood products
 
If the AVM is not exposed and cannot be readily clipped:
=== Induction and airway management<!-- Describe the important considerations and general approach to the induction of anesthesia and how the airway is typically managed for this case. --> ===
*Intraoperative rupture without exposure can be difficult to detect
 
**Be suspicious of this possibility with unexplained hypertension and bradycardia
* Stable induction of general anesthesia and intubation with fentanyl, propofol, rocuronium, and +/- vasoactive agents to avoid hypo- and hypertension. Typically MAP >65 and SBP <140, however surgical team preferences can vary.
*Ensure CPP is optimized between CPP 50 to 70 mmHg, generally this would require '''increasing''' the MAP.
* Moderate hyperventilation (PaCO2 30 mmHg)
**Despite ongoing bleeding, brain perfusion is still critical
 
*Ensure adequate oxygenation and ventilation
=== Maintenance and surgical considerations<!-- Describe the important considerations and general approach to the maintenance of anesthesia, including potential complications. Be sure to include any steps to the surgical procedure that have anesthetic implications. --> ===
*Consider decreasing ICP with head elevation, mannitol, or hypertonics if concern for critical ICP, though this may worsen bleeding
Patients typically receive Cefazolin, 10 mg of decadron and 1 gm/kg of mannitol on skin incision (verify all with surgeon). Keppra 1g may also be utilized
===Emergence<!--List and/or describe any important considerations related to the emergence from anesthesia for this case.-->===
 
*After resection, normotension (MAP 70-90) is typically preferred
Anesthesia can be maintained safely with many different medications, and can be guided primarily by other coexisting conditions.
*Goals are similar to other neurosurgical procedures, including a smooth emergence, avoiding hypertension, coughing, and straining
 
*Intraoperative medications should be titrated down to allow for a rapid return to consciousness to permit neurologic examination prior to leaving the operating room
* An isoflurane/N2O technique offers hemodynamic stability and quick wake up test if needed. This benefit is offset by increased risk of PONV and possibility for N2O closed space expansion.
==Postoperative management==
* TIVA is a reasonable option however it may not allow for a rapid wake up test if needed
===Disposition<!--List and/or describe the postoperative disposition and any special considerations for transport of patients for this case.-->===
* Inhalational and intravenous combination may optimize rapid emergence if needed.
*ICU for neuro checks
* One example could be propofol infusion (approximately 50mcg/kg/min), remifentanil infusion, vecuronium infusion, and sevoflurane
*Postoperative CT/MRI
*Hemodynamic "uppers and downers" should be available. For example: esmolol, labatelol, nitroglycerine, nicardipine infusion. Phenylephrine, norepinephrine drip. Adenosine can also be utilized for temporary cessation of cardiac output if surgical team requests. 
*If ruptured, risk of vasospasm highest 3-8 days after rupture
 
===Pain management<!--Describe the expected level of postoperative pain and approaches to pain management for this case.-->===
=== Emergence<!-- List and/or describe any important considerations related to the emergence from anesthesia for this case. --> ===
*Consider scalp block prior to emergence
Goals are similar to other neurosurgical procedures, including a smooth emergence, avoiding hypertension, coughing, and straining. Intraoperative medications should be titrated down to allow for a rapid return to consciousness to permit neurologic examination prior to leaving the operating room. Alternatively, postoperative CT is sometimes utilized if a neurological exam can not be performed.
*Acetaminophen
 
=== Potential complications<!-- List and/or describe any potential postoperative complications for this case. -->===
Perioperative bleeding from AVM, cerebral ischemia from brain swelling, retractor pressure, inadequate CPP (increased ICP, vasospasm), postoperative intracranial hemorrhage, postoperative brain edema.
 
== Postoperative management ==
 
=== Disposition<!-- List and/or describe the postoperative disposition and any special considerations for transport of patients for this case. --> ===
Neuro Critical Care Unit
 
== Procedure variants<!-- This section should only be used for cases with multiple approaches (e.g. Laparoscopic vs. open appendectomy). Otherwise, remove this section. Use this table to very briefly compare and contrast various aspects between approaches. Add or remove rows as needed to maximize relevance. Consider using symbols rather than words when possible (e.g. +, –, additional symbols such as ↑ and ↓ are available using the "Ω" tool in the editor). --> ==
 
{| class="wikitable wikitable-horizontal-scroll"
|+
!
!Variant 1
!Variant 2
|-
|Unique considerations
|
|
|-
|Position
|
|
|-
|Surgical time
|
|
|-
|EBL
|
|
|-
|Postoperative disposition
|
|
|-
|Pain management
|
|
|-
|Potential complications
|
|
|}
 
== References ==


==References==
<references />
[[Category:Surgical procedures]]
[[Category:Surgical procedures]]
<references />
[[Category:Neurosurgery]]
[[Category:Neurosurgery]]
[[Category:Intracranial neurosurgery]]
[[Category:Intracranial neurosurgery]]

Latest revision as of 15:25, 12 December 2023

Craniotomy for intracranial vascular malformations
Anesthesia type

General

Airway

ETT

Lines and access

Large bore IV x2 Arterial line ± Central line (if arterial nidus)

Monitors

Standard 5-lead ECG Core temp UOP ABG ± CVP (if arterial nidus) Neuromonitoring

Primary anesthetic considerations
Preoperative

Characterize neurologic deficits

Intraoperative

Smooth induction Hemodynamic goals vary Hypotension ↑ risk of steal If arterial nidus:

  • Hypertension ↑ risk of rupture
  • Have adenosine available
  • Decrease CRMO2
Postoperative

Avoid hypertension after excision (risk of hyperemia)

Article quality
Editor rating
Comprehensive
User likes
0

A craniotomy for intracranial vascular malformations is a neurosurgical procedure performed to remove vascular malformations which are considered high risk for rupture or produce neurologic symptoms.

Overview

Background

  • Intracranial vascular malformations are congenital defects
  • Typically present in young adulthood (most commonly 15-40 years old)
  • Wide anatomic variability[1]
    • High-flow arteriovenous malformations (AVM)
    • Low-flow angiographically occult vascular malformations (AOVM)
      • Cavernous malformations
      • "Cryptic" AVMs
      • Capillary telangiectasias
      • Transitional malformations
    • Low-flow venous angiomas
  • Patients may be symptomatic or asymptomatic
  • AVM may have be ruptured or unruptured and can be associated with vasospasm. Can also co exist with aneurysms. Most patients will have anesthesia for preoperative embolization of the AVM.

Indications

  • The Spetzler-Martin AVM grading system estimates morbidity and mortality of surgery[2]
Spetzler-Martin AVM grading scale
Supplemental AVM grading scale

Surgical procedure

Preoperative management

Patient evaluation

System Considerations
Airway If acute, consider RSI
Neurologic Unruptured vs. ruptured important for risk stratification. Neurologic symptoms and mental status, signs and symptoms of elevated ICP, seizures
Cardiovascular If acutely ruptured, can be associated with hypertension as well as other cardiac abnormalities including ischemia, arrhythmias, left ventricular dysfunction, and pulmonary edema.
Hematologic Anemia

Labs and studies

  • BMP
  • CBC
  • Coags
  • Type and screen
  • Brain MRI

Operating room setup

  • Rapidly titratable vasoconstrictors and vasodilators in bolus syringes and infusions to acutely manage blood pressure
    • Phenylephrine or norepinephrine
    • Clevidipine, nitroprusside, or nitroglycerine. Nicardipine less desirable intraoperatively given longer pharmacokinetics.
  • Adenosine (at least 1 mg/kg rapidly available)
  • Osmotic agents (mannitol and/or hypertonic saline)
  • Crossmatched blood should be available

Patient preparation and premedication

  • Midazolam often beneficial to prevent anxiety-induced hypertension
  • Consider aprepitant 40 mg PO for additional PONV prophylaxis
  • See hemodynamic management section below

Regional and neuraxial techniques

  • Consider postoperative scalp block for analgesia

Intraoperative management

Overall Goals

Goals are to provide a stable hemodynamic anesthetic along with reducing/normalizing the ICP and maintaining adequate CPP (at least 60-70 mmHg) to prevent cerebral ischemia from brain retraction, brain swelling and vasospasm. Perioperative AVM rupture from hypertension is possible, but rare. However, in case of a coexisting aneurysm, hypertension must be avoided.

Monitoring and access

  • Standard ASA
  • 5-lead ECG
  • Core temperature
    • Consider bladder temperature monitoring if using mild hypothermia
  • Arterial line
  • 2 large bore IVs
  • Consider central access
    • Rapid administration of vasoactives, adenosine
    • Peripheral vasoconstriction may limit drug delivery if using hypothermia
    • CVP monitoring, though added value is unclear
  • Evoked potential monitoring
  • EEG monitoring
  • External ventricular drain may be useful for ICP monitoring and management if ruptured

Hemodynamic management

If ICP monitoring is available, maintain cerebral perfusion pressure near 60 mmHg.

Unruptured AVMs

  • Preoperatively: Maintain blood pressure at or below patient's baseline.
  • Intraoperatively: Target MAP 60-80 mmHg.**If hypertensive at baseline, baseline blood pressure may pose rupture risk once dura is opened and/or aneurysm is exposed (since transmural pressure gradient will increase)

Ruptured AVMs

  • Preoperatively:
    • Passive hypertension may represent beneficial reflex to maintain cerebral perfusion pressure in the setting of increased intracranial pressure, and should probably not be treated.
    • Hypertension due to noxious stimuli (i.e. pain, anxiety, disinhibition) should be avoided and appropriately treated depending on etiology (e.g. analgesics, anxiolytic, sedation).
  • Intraoperatively: Target MAP 60-80 mmHg.

Induction and airway management

  • Hemodynamically stable induction of general anesthesia and intubation is critical
    • Fentanyl, propofol, rocuronium, and +/- vasoactive agents to avoid hypo- and hypertension.
  • Moderate hyperventilation (PaCO2 30 mmHg) may be useful if concern for elevated ICP

Maintenance and surgical considerations

  • Brain relaxation (hyperventilation, osmotic agents, CSF removal) should be used with caution in ruptured aneurysms
    • Decreased ICP can increase transmural pressure and increase risk of re-rupture/worsen bleeding
    • Risk/benefit should be discussed with surgeons
  • Antibiotics (cefazolin 2-3 g)
  • Dexamethasone (8-10 mg)
  • ± Antiepileptics (levetiracetam 1 g)

Anesthetic maintenance

Anesthesia can be maintained safely using several techniques, and should be guided by provider experience, institutional practices, and unique patient considerations

  • Many centers recommend the use of total intravenous anesthesia with propofol and remifentanil
    • Cerebral vasocontriction from propofol may be desirable
    • Limited interference with evoked potential monitoring
    • Antiemetic effect of propofol desirable
    • EEG monitoring essential to ensure drug delivery and allow dose titration
  • Some centers use volatile anesthetics and/or nitrous oxide
    • Inhaled anesthetic somewhat mitigates risk of line infiltration and patient emergence/movement while in pinned frame
    • ≤0.5 MAC of volatile anesthetic will limit cerebral vasodilation, decoupling of autoregulation and interference with evoked potential monitoring
    • Consider risk of nitrous oxide expansion of pneumocephalus
  • A combination of techniques can be used to leverage the benefits of each approach. For example:
    • Sevoflurane 0.5 MAC
    • Propofol 50-75 mcg/kg/min
    • Remifentanil 0.1-0.2 mcg/kg/min
    • Anesthetic and analgesic agents titrated using EEG

Temporary clipping

In some circumstances, surgeons may place a temporary clip proximal to the aneurysm to occlude flow and allow dissection and exposure without rupture. However, this can create focal ischemia distal to the clip/aneurysm. To minimize the risk of worsened neurologic outcomes, consider:

  • Minimize temporary clip time
  • Increase MAP (~90 mmHg) after clip placement to facilitate collateral perfusion
  • Evoked potential monitoring to provide realtime feedback to surgeons
  • Minimal evidence to support neuroprotective measures[3]
    • Some providers still use induce burst suppression with a propofol bolus (~1 mg/kg) immediately prior to temporary clip placement due to the relative ease of rapid induction with minimal risk to hemodynamic stability
      • Concurrent bolus of vasoconstrictor often required to maintain stable MAP
    • Hypothermia not associated with improved outcomes during temporary clipping

Potential complications

AVM rupture

Intraoperative AVM rupture can happen at any time until the malformation is resected. AVM rupture is a true emergency that requires rapid intervention.

If the AVM is exposed:[4]

  • Improve surgical visualization by decreasing/stopping bleeding rate to allow clip placement
    • Discuss with surgeons
    • Typically start with induced hypotension (MAP 50-60) using a short acting agent (e.g. clevidipine or esmolol)
    • If insufficient, consider inducing temporary flow arrest (asystole) using adenosine 0.3-0.6 mg/kg[5]
      • If ineffective arrest achieved, double adenosine dose
      • Doses as high as 2 mg/kg have been reported as necessary
  • Reduce CMRO2 with propofol 0.5-1 mg/kg bolus, increase infusion rate
  • Resuscitate as indicated with IVF or blood products

If the AVM is not exposed and cannot be readily clipped:

  • Intraoperative rupture without exposure can be difficult to detect
    • Be suspicious of this possibility with unexplained hypertension and bradycardia
  • Ensure CPP is optimized between CPP 50 to 70 mmHg, generally this would require increasing the MAP.
    • Despite ongoing bleeding, brain perfusion is still critical
  • Ensure adequate oxygenation and ventilation
  • Consider decreasing ICP with head elevation, mannitol, or hypertonics if concern for critical ICP, though this may worsen bleeding

Emergence

  • After resection, normotension (MAP 70-90) is typically preferred
  • Goals are similar to other neurosurgical procedures, including a smooth emergence, avoiding hypertension, coughing, and straining
  • Intraoperative medications should be titrated down to allow for a rapid return to consciousness to permit neurologic examination prior to leaving the operating room

Postoperative management

Disposition

  • ICU for neuro checks
  • Postoperative CT/MRI
  • If ruptured, risk of vasospasm highest 3-8 days after rupture

Pain management

  • Consider scalp block prior to emergence
  • Acetaminophen

References

  1. Anesthesiologist's manual of surgical procedures. Richard A. Jaffe, Clifford A. Schmiesing, Brenda Golianu (6 ed.). Philadelphia. 2020. ISBN 978-1-4698-2916-6. OCLC 1117874404.CS1 maint: others (link)
  2. Spetzler, R. F.; Martin, N. A. (1986-10). "A proposed grading system for arteriovenous malformations". Journal of Neurosurgery. 65 (4): 476–483. doi:10.3171/jns.1986.65.4.0476. ISSN 0022-3085. PMID 3760956. Check date values in: |date= (help)
  3. Hindman, Bradley J.; Bayman, Emine O.; Pfisterer, Wolfgang K.; Torner, James C.; Todd, Michael M.; IHAST Investigators (2010-01). "No association between intraoperative hypothermia or supplemental protective drug and neurologic outcomes in patients undergoing temporary clipping during cerebral aneurysm surgery: findings from the Intraoperative Hypothermia for Aneurysm Surgery Trial". Anesthesiology. 112 (1): 86–101. doi:10.1097/ALN.0b013e3181c5e28f. ISSN 1528-1175. PMID 19952722. Check date values in: |date= (help)
  4. Laurel E Moore, Magnus K Teig, Vijaykumar Tarnal (4/1/2022). "Anesthesia for intracranial neurovascular procedures in adults". Check date values in: |date= (help)CS1 maint: multiple names: authors list (link)
  5. Desai, Virendra R.; Rosas, Alejandro L.; Britz, Gavin W. (2017). "Adenosine to facilitate the clipping of cerebral aneurysms: literature review". Stroke and Vascular Neurology. 2 (4): 204–209. doi:10.1136/svn-2017-000082. ISSN 2059-8696. PMC 5829927. PMID 29507781.