SPETZLER-MARTIN GRADE III ARTERIOVENOUSMALFORMATIONS: SURGICAL RESULTS AND A

MODIFICATION OF THE GRADING SCALE

Michael T. Lawton, M.D.Department of Neurological Surgery, University of California, San Francisco, San Francisco,

California

Neurosurgery 2003, April, Volume 52, Number 4

A Supplementary Grading Scale for Selecting Patients with Brain

Arteriovenous Malformations for Surgery

Neurosurgery 2010, April, Volume 66, Number 4

Michael T. Lawton, M.D.Department of Neurological Surgery, University of California, San Francisco, San Francisco,

California

Methods - Neurosurgery 2003

174 AVM’s (174 patients) in 4.8 years

- 76 AVMs (45.2%) were Grade III

- Consecutive analysis

Why study Grade III?

Low-grade AVMs (Grades I and II) have low morbidity rates (0–5%) associated with their resection

Surgery

High-grade AVMs (Grades IV and V) have high morbidity rates (12-38%) associated with their resection

Monitorization

Why study Grade III?

Heterogenous: 4 different combination - Size

- Venous drainage - Eloquence

Combinations:

-S1V1E1 -S2V1E0 -S2V0E1 -S3V0E0

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Size:

1 < = 3cm2 = 3- 6

cm3 > =6cm

Venous drainage:

0 = Superficial1 = Deep

Eloquenc

e:0 = No1 = Yes

Results

Improved Unchanged Worse Dead Lost to monitoring Total

S1V1E1 18 (51.4%) 15 (42.9%) 0 (0.0%) 1 (2.9%) 1 (2.9%) 35S2V1E0 4 (28.6%) 9 (64.3%) 1 (7.1%) 0 (0.0%) 0 (0.0%) 14

S2V0E1 9 (33.3%) 14 (51.9%) 2 (7.4%) 2 (7.4%) 0 (0.0%) 27S3V0E0 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0

Total 31 (40.8%) 38 (50.0%) 3 (3.9%) 3 (3.9%) 1 (1.3%) 76

Modification of the Spetzler-Martin grading scale

S1V1E1 = S&M III-can be safely treated with microsurgical resection

S2V0E1 = S&M III +have higher than expected surgical risks and might be better managed

conservatively(like many high-grade AVMs)

S2V1E0 = S&M III require carefully individualized treatment recommendations

and planning

S3V0E0 = S&M III*are either nonexistent or exceedingly rare, with a surgical risk that is

unclear