AVM

1. ARTERIO-VENOUS
MALFORMATION(AVM)

2. • DIRECT CONNECTION BETWEEN ARTERY AND
VEIN BYPASSING THE CAPILLARY
• DECREASED O2 DELIVERY
• INCREASED O2 IN VENOUS BLOOD

3. AVM
• DEPENDING ON THE FLOW
• LOW FLOW
• HIGH FLOW
– PRIMARY
– SECONDARY(LOW FLOW PROGRESSES TO HIGH
FLOW IN ADULT )

4. AVM
• CONGENITAL
• ACQUIRED
• THERE ARE ANGIOGRAPHICALLY OCCULT
VASCULAR MALFORMATION
• OSLER-WEBER RENDU SYNDROME – 15-20%

5. THIS NIDUS SITE IS PRONE FOR
RUPTURE AS THE FLOW INCREASES
THE THIN WALLED VEIN CANNOT
HANDLE THE BLOOD

6. • SINCE THERE IN NO DAMPENING OF FLOW IN
THE BLOOD, AS THERE IS NO CAPILLARY….

7. TYPES OF AVM
• PARENCHYMAL AVM
• YELLOW – PIAL AVM
• RED – PARAVENTRICULAR AVM
• GREEN –SUBCORTICAL AVM
• MIXED

8. • DURAL AVM
• MIXED (DURAL AND PARENCHYMAL AVM)

9. CLINICAL PRESENTATION
• HEMORRHAGE(INTRAPARENCHYMAL>INTRAVENTRICU
LAR HEMORRHAGE >SUBARACHNOID HEMORRHAGE )
• MASS EFFECT
IF ON TRIGEMINAL NERVE – TRIGEMINAL
NEURALGIA(ALWAYS MRI)
SEIZURES
ISCHEMIA BY STEAL
INCREASED ICP

11. INVESTIGATION
• CT
• MRI ANGIOGRAPHY

12. SPETZLER MARTIN GRADING

13. MANAGEMENT
• SURGICAL RESECTION
• EMBOLISATION
– Onyx-18, 34 – AVM
– ONYX 500 - ANEURYSM
• STEREOTACTIC RADIOSURGERY
– FOR DEEPER LESION OF LESS THAN 3 CM

14. POST OPERATIVE COMPLICATION
• NORMAL PERFUSION PRESSURE BREAKTHROUGH
– Swelling or hemorrhage due to loss of autoregulation
- Patient pretreated with propanolol 20mg QID TO
MINIMISE THIS EFFECT
• OCCLUSIVE HYPEREMIA.
– MAY BE DUE TO OCCLUSION OF DRAINING VEIN OR
DUE TO THROMBOSIS (DELAYED EFFECT)

15. • POST OPERATIVELY
– CATHETER ANGIOGRAPHY AT 1 YEAR AND AT 5
YEAR AFTER TREATMENT

16. THANK YOU