What’s the diagnosis?
- The Spetzler-Martin grading scale for arteriovenous malformations of the brain was developed to predict the outcome of microsurgical treatment and is widely used to describe these malformations.
- This five-grade scale incorporates points for three important features of an arteriovenous malformation: 1) the largest diameter of the nidus of the malformation as measured on angiography; 2) the presence of deep venous drainage (e.g., the internal cerebral veins, basal veins, or precentral cerebellar vein); and 3) eloquent location (e.g., motor, sensory, language, and visual cortex or basal ganglia).
- The general microsurgical strategy is to first cauterize feeding arteries and then draining veins. The goal is complete removal of the malformation as a single specimen.
- For Spetzler-Martin grade 1 or 2 arteriovenous malformations, the risk of new, permanent neurological deficits after microsurgery is felt to be less than 5% amongst experienced surgeons.
- However, the risk of neurological injury increases dramatically with higher grade arteriovenous malformations.