Spinal arteriovenous malformation (AVM) is a rare, abnormal tangle of blood vessels on, in or near the spinal cord. Without treatment, spinal AVM can permanently damage your spinal cord.
Oxygen-rich blood normally enters your spinal cord through arteries, which branch into smaller blood vessels (capillaries). Your spinal cord uses the oxygen from the blood in your capillaries. The oxygen-depleted blood then passes into veins that drain blood away from your spinal cord to your heart and lungs.
In a spinal AVM, the blood passes directly from your arteries to your veins, bypassing the capillaries.
This disruption in blood flow deprives the surrounding cells of vital oxygen and causes cells in your spinal tissues to deteriorate or die.
The arteries and veins in a spinal AVM can also rupture and cause bleeding in the spinal cord (hemorrhage). Sometimes, the AVM may enlarge over time as blood flow increases and compress the spinal cord, leading to disability or other complications.
Spinal AVM can go undiagnosed unless you begin experiencing signs and symptoms. The condition can be treated with surgery to halt or possibly reverse some of the spinal damage.
Spinal AVM care at Mayo Clinic