Shi-Chen Scale for Grading an Intracranial Arteriovenous Malformation (AVM)

Parameter

Finding

Grade

size in cm (diameter)

< 2.5 cm

1

2.5 - 5.0 cm

2

5.01 - 7.5 cm

3

> 7.5 cm

4

location and depth

superficial and non-crucial area

1

superficial and in functional area

2

deep not involving a vital structure

3

deep involving a vital structure of the brain (brainstem, diencephalon, etc.)

4

arterial blood supply

single superficial branch of the middle and/or anterior cerebral artery

1

multiple superficial branches of the middle and/or anterior cerebral artery

2

(branches of the posterior cerebral artery) or (deep branches of the middle cerebral artery) or (deep branches of the anterior cerebral artery) or (branches of the vertebral artery)

3

(verebrobasilar artery) or (main branches from all 3 cerebral arteries)

4

venous drainage

single, emptying into superficial dural sinuses

1

multiple, all drainage into superficial dural sinuses

2

(deep cerebral vein emptying into vein of Galen or straight sinus) or (superficial venous drainage)

3

deep cerebral vein with huge dilatation or aneurysm-like structures

4

Pattern of 4 Grades

Final Grade

all Grade 1

I

3 Grade 1, 1 Grade 2

I-II

2 Grade 1, 2 Grade 2

II

1 Grade 3, 3 Grades 1 and/or 2

II-III

2 Grade 3, 2 Grades 1 and/or 2

III

<1 Grade 4, 3 others>

III-IV

<2 or more Grade 4, others>

IV

Final Grade

Operative Morbidity

I

0%

I-II

0%

II

0%

II-III

17%

III

20%

III-IV

80%