Arteriovenous Malformation (AVM)

Question 1

What characterizes an arteriovenous malformation (AVM)?

Answer 1

an arterial to venous connection without intervening capillaries, resulting in high flow, low resistance shunting.

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Question 2

What is the commonly believed origin of arteriovenous malformations?

Answer 2

AVMs are believed to be congenital.

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Question 3

What is the range of symptoms for arteriovenous malformations?

Answer 3

Symptoms can range from mass-effects to hemorrhage.

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Question 4

Where are the majority of arteriovenous malformations located?

Answer 4

The majority of AVMs are supratentorial.

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Question 5

How are arteriovenous malformations diagnosed?

Answer 5

via angiography and MRI.

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Question 6

What pre-anesthesia assessments are important for patients with arteriovenous malformations?

Answer 6

• history and physical
• review of medications
• imaging
• CBC
• BMP
• type and crossmatch
• EKG
• echocardiogram.

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Question 7

What are the treatment options for arteriovenous malformations?

Answer 7

• radiation
• angio-guided embolization
• surgical resection (carries a higher mortality risk)

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Question 8

What are key considerations in the pre-anesthesia management of arteriovenous malformations?

Answer 8

• focus on BP control
• potential use of mannitol
• seizure prophylaxis
• ensuring large bore IV access x2, and arterial line placement.

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Question 9

How is the nidus size of an AVM graded in the Spetzler-Martin system?

Answer 9

Nidus size is graded as small (<3 cm) for 1 point, medium (3-6 cm) for 2 points, and large (>6 cm) for 3 points.

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Question 10

What does eloquence of adjacent brain mean in the Spetzler-Martin AVM grading system?

Answer 10

Eloquent brain areas are those that, if affected, would result in a significant neurological deficit. Eloquent areas score 1 point, while noneloquent areas score 0 points.

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Question 11

How is the pattern of venous drainage graded in the Spetzler-Martin AVM system?

Answer 11

The pattern of venous drainage is graded as superficial only for 0 points and deep only or deep and superficial for 1 point.

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Question 12

What is the likelihood of no postoperative neurological deficit with a Spetzler-Martin AVM grade of 1?

Answer 12

There is a 100% chance of no postoperative neurological deficit with a Spetzler-Martin AVM grade of 1.

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Question 13

How does the Spetzler-Martin AVM grade correlate with the percentage of patients with no postoperative neurological deficit?

Answer 13

Grade 1 correlates with 100% of patients having no deficits, grade 2 with 95%, grade 3 with 84%, grade 4 with 73%, and grade 5 with 69% having no postoperative neurological deficits.

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