Ventricular drainage refers to the process of withdrawing cerebrospinal (CSF) fluid from the brain in order to relieve pressure inside the skull. A thin plastic tube, called a catheter, is placed into ventricles in the brain that contain the fluid. The catheter is attached to a drainage bag outside the body where the fluid is collected.
An external ventricular drain (EVD) may be necessary for a variety of reasons. It may be that the natural system of expelling excess CSF no longer functions properly, and an external drainage route is needed. Alternatively, the CSF may have become infected, and drainage is needed to remove that infection from the brain. CSF may also be removed from the brain to relieve intracranial pressure (ICP) generally. A variety of medical conditions, including brain tumors, aneurysms, strokes, abscesses, shunts and brain infections can result in the need for an EVD.
Usually, EVDs are used in life-saving, emergency procedures. They are inserted by a neurosurgeon in an operating room while the patient is under general anesthesia. Generally, a small area is shaved on the head and the doctor will make a tiny incision in the scalp. Through this incision, the doctor is able to insert the tube into the area of the brain containing a ventricle. Extra fluid that accumulates in this area can then be drained to the external collection bag. The tube is then stitched beneath the skin.
Postoperatively, the fluid in the collection bag is carefully monitored. System pressures and settings are assessed so that the proper level of brain pressure is maintained. Headache severity and frequency as well as temperature and analysis of brain fluid are assessed. Complications can occur in the form of infection or bleeding inside the brain. Other risks include meningitis, stroke, CSF leakage, and death.
How long the EVD remains placed in the patient's skull varies though it is usually removed within 10 days. The ventricular catheter is also removed while the patient is under general anesthesia. If surgery is not successful in alleviating the problem, a shunt may be required.
Long term, there are usually no effects other than a small scar where the catheter was inserted. Postoperative follow-up appointments with a doctor or neurosurgeon are often necessary to prevent adverse repercussions as well as monitor the reason why the ventricular drainage system was needed in the first place.