What is a chronic subdural hematoma?

A chronic subdural hematoma is bleeding in the brain that occurs between two specific layers of tissue that line the brain – the subdural and arachnoid membranes. In elderly patients, this is most often caused by injury to a vein that traverses this space. Even minor trauma can cause a subdural hematoma. Over time, the blood vessels associated with these tissue planes may become abnormally enlarged as a result of the subdural hematoma. Subdural hematomas are dangerous in that they can cause pressure on the brain structures.

How is a chronic subdural hematoma treated?

Chronic subdural hematomas are surgically managed in a variety of ways, ranging from small holes made in the skull, to more involved surgical techniques to remove the blood collection. A relatively new procedure, chronic subdural hematoma embolization is an effective means of halting this process, or even decreasing the size of the subdural hematoma in order to avoid the need for surgery.

How is a chronic subdural hematoma embolization performed?

The basic technique starts with a similar access approach to a diagnostic cerebral angiogram. A tiny catheter (microcatheter) is advanced into an artery known as the middle meningeal artery (MMA), which is considered the main culprit in the cascade of events that lead to chronic subdural hematomas. Tiny particles of polyvinyl alcohol (PVA) are infused into the artery to block off the various abnormally enlarged branches. Patients have highly variable anatomies, so great care in angiographic interpretation is necessary. Not uncommonly, patients may have prominent channels between the MMA and the artery of the eye (ophthalmic artery). In those cases, it is unsafe to perform embolization.