Spinal vascular malformations AVF/AVM

• Some combined AVF, AVF and Spinal vascular neoplasms

• Some only have AVMs

flowchart TD
    A["TRiCKs MRA"] --> B["Suggests<br>Single Fistula Level"]
    A --> C["Level not<br>identified"]
    B --> D["Targeted DSA<br>(L.A.) +/- 2 levels"]
    C --> E["Complete<br>Spinal Angiography"]

• MR
• Tricks sq (Time resolved contrast enhanced MR angiography)
• To isolate level
• For all classes when compared to DSA
• Sensitivity : 93%
• Specificity 63%
• PPV: 93%
• NPV: 83%

• Spinal DSA
• Gold standard
• Not used as first line because
• Heavy contrast load
• Radiation exposure
• Time consuming as you need to imaging every level to find the offending vessel
• General anaesthesia
• Pt needs to lie down for long and not move
• Staging of procedure

• Aminoff-logue grading system
• Made for the clinical assessment of patients with spinal vascular lesion
• 2 components
• Gait

Grade	Definition
0	Normal
1	Leg weakness, abnormal gait, or stance without limitation of activity
2	Restricted activity
3	Requires one stick or similar support
4	Requires crutches or two sticks to walk
5	Unable to stand, bed-bound, or in a wheelchair

• Micturition

Grade	Definition
0	Normal
1	Hesitancy, frequency, or urgency
2	Occasional incontinence or retention
3	Permanent urinary incontinence or retention

• Summary

ㅤ	Arteriovenous Fistulas	ㅤ	ㅤ	Arteriovenous Malformations	ㅤ	ㅤ
Kim and Spetzler (barrow) classification	Intradural Dorsal	Intradural Ventral	Extradural	Intramedullary	Extradural-Intradural	Conus Medullaris
Wyburn-Mason	Angioma racemosum venosum	N/A	N/A	Angioma racemosum arteriovenosum	N/A	N/A
Rosenblum et al	Dural AVF	Intradural AVF	N/A	Intradural AVM (glomus and juvenile)	N/A	N/A
Di Chiro (American/English/French)	Type I	Type IV (perimedullary fistula)	N/A	Type II (glomus)	Type III (juvenile)	N/A
Borden et al	Type III	N/A	Type I	N/A	Type II	N/A
Niimi and Berenstein	Spinal dural fistula	Spinal dural fistula	Spinal extradural AVF	Isolated spinal cord AVM	Multiple spinal cord AVMs	N/A
Bao and Ling	Dural AVF	Intradural AVF	N/A	Intramedullary AVM (glomus and juvenile)	N/A	N/A

• Spinal Metameric AVM
• The “metameric” part refers to the fact that our bodies are, fundamentally, made in segments or blocks.
• For example, each pair of ribs, the vertebral bone they are attached to, adjacent muscle, fat, skin, and a piece of spinal cord at that level are built from one segment of embryonic tissues.
• Another word for segment is “metamere”, and from that comes the term “metameric”.

• Di Chiro aka American/English/French aka international classification -→

Type	Description	Subtype	Location	Feeding vessel	Draining vessel	Pressure	Flow	Etiology
I	Spinal dural arteriovenous fistulas	A Single fistula B Polyfistulous	Thoracic Conus	Single transdural radicular artery	Perimedullary	↑	↓	Acquired
II	Intramedullary (Glomus) arteriovenous malformations		Cervico-medullary junction	Multiple radiculomedullary arteries	Epidural venous plexus	↑	↑	Congenital
III	Juvenile/metameric malformations		Entire cord (extra- and intramedullary)	Multiple radiculomedullary arteries	Bidirectional, epidural venous plexus	↑	↑	Congenital
IV	Perimedullary spinal cord arteriovenous fistulas	A) Single fistula B) Often multiple, intermediate flow C) Polyfistulous, large lesions	Conus (anterosuperior to cord)	Anterior spinal artery		↑	↓	Congenital

• Kim and Spetzler (barrow) classification
• Based on angiographic findings of anatomic features and pathophysiologic mechanisms
• Newest
• Differentiates into
• AVF
• Intradural Dorsal
• Intradural Ventral
• Extradural
• AVM
• Intramedullary
• Extradural-intradural
• Conus medullaris