Spinal Dural Arteriovenous Fistula
What is it?
Spinal dural arteriovenous fistula (SDAVF) is a rarely seen vascular lesion in the spinal cord that is often overlooked. If left untreated in the early stages, it is associated with severe morbidity, and may lead to progressive myelopathy and bladder and bowel dysfunction.
Normally, arteries and veins are connected by tiny vessels called capillaries, but in an SDAVF, the capillaries are missing, and arteries and veins are directly connected to each other. The direct connection between artery and vein is called a fistula, and it leads to a number of problems, because veins are not equipped to properly receive the high-pressure arterial blood. They can swell and bloat, which places harmful pressure on the spinal cord.
Symptoms
Symptoms of SDAVF are generally similar to symptoms of many other problems that affect the spinal cord. These symptoms may include back pain, numbness, weakness, clumsiness, difficulty walking, impairment in bladder or bowel function, and sexual dysfunction. Many patients have symptoms for a year or more before the SDAVF is diagnosed.
Diagnosis
SDAVFs are usually identified by an MRI (magnetic resonance imaging) scan, and angiogram.
Treatment
Although treatment is individually planned for each SDAVF patient, two effective treatment methods are microsurgery occlusion and endovascular embolization. Endovascular embolization is the first preferred method, as it is less invasive, allows starting rehabilitation earlier, and does not completely eliminate the option of having surgery, which may be necessary in some cases. If surgery is necessary, spinal surgeon can microsurgically remove the malformation and restore the normal blood flow to the spinal cord.