It is most commonly used for the treatment of hydrocephalus or elevated intracranial pressure. CSF is a clear liquid that surrounds and cushions the brain and spinal cord. Overproduction or impaired absorption of CSF can cause hydrocephalus, which is a condition where there is excessive accumulation of CSF in the ventricles or tissue of the brain.

Procedure for Placement of an External Ventricular Drain Industry

External Global External Ventricular Drain are placed surgically by a neurosurgeon. The patient is taken to the operating room and placed under general anesthesia. The neurosurgeon makes a small opening in the skull, called a burr hole, just above and behind one ear. Next, a soft plastic catheter is inserted through the burr hole and guided using imaging guidance into one of the ventricles of the brain. The catheter is then tunneled underneath the scalp and connected to a drainage and monitoring system that is secured outside the body. This system is used to drain off and measure the amount of CSF that is being collected. Sterile dressings are applied over the catheter exit site to minimize risk of infection.

Drainage and Monitoring System

The drainage and monitoring system connected to the external ventricular drain has three main components - a drainage bag, collection chamber, and variable pressure controller. The drainage bag collects the drained CSF and hangs below the level of the head for proper gravity drainage. It contains measurement markings to track CSF output. The collection chamber allows for sampling of CSF to check for signs of infection. The variable pressure controller regulates CSF drainage pressure and contains pressure monitoring capabilities. It is set to allow intermittent or continuous drainage of CSF at a prescribed pressure setting tailored for each patient's needs.

Post-Placement Management and Care

After an EVD placement, patients require close monitoring in an intensive care unit or neuro ICU setting. Nursing staff monitors catheter function and checks drainage amount, pressure readings, and exit site every 1-2 hours initially. Neuro checks are also performed regularly to assess changes in neurological status. Any signs of infection such as fever, headache, or drainage site redness are reported promptly. The catheter may need periodic adjustment or repositioning under imaging guidance to ensure proper placement and drainage patency. Antibiotic administration and measures to prevent infection are important aspects of care. Serial CSF analyses check for rising white blood cell counts indicating possible catheter-related or other CNS infection. The EVD system is typically in place for several days or weeks until ICP is controlled and the underlying cause of hydrocephalus is addressed definitively.

Alternative Treatments to EVD

There are some alternatives to external ventricular drainage that may be considered in certain clinical situations:

Ventriculoperitoneal (VP) Shunt - This involves permanent internalization of the catheter and connection of the ventricular end to the peritoneal cavity for long-term drainage of CSF into the abdomen. VP shunts carry some risk of dislocation, obstruction, or infection but provide definitive hydrocephalus treatment if successful.

Endoscopic Third Ventriculostomy (ETV) - A minimally invasive procedure where an opening is created in the floor of the third ventricle using an endoscope passed through a small burr hole. This opening created allows CSF to bypass obstruction and drain more naturally. ETV avoids long-term hardware but success depends on underlying cause and ventricular anatomy.

Lumbar Peritoneal (LP) Shunt - Similar to VP shunt but drains CSF from the lumbar cistern area in the lower back into the peritoneal cavity instead of from ventricular system. Used less commonly than VP shunt but an option if ventricles cannot safely be accessed.

Serial Lumbar Punctures - Repeated removal of small amounts of CSF via lumbar puncture allows temporary reduction of ICP. Not a permanent solution but can control ICP in acute settings or serve as a bridge to more definitive procedures.

Stereotactic Ventricular Drainage - Involves neurosurgical placement of sealed catheters into the ventricular system under image-guided navigation systems for short-term control of ICP elevation during recovery from processes like trauma or hemorrhage. A less invasive alternative to EVD that avoids external hardware.

Risks and Complications of EVD

While external ventricular drains are generally a safe and effective treatment, there are risks involved including:

Hemorrhage - Small risk of bleeding during placement through brain tissue and ventricles. Increased risk in elderly patients on anticoagulants.

Infection - Catheter-related infections of the ventricles or surrounding tissues are a concern. Strict sterile technique and antibiotic administration aim to prevent this.

Malposition - The catheter tip could terminate in the wrong ventricle or tissue plane rather than ventricular system. Imaging verifies correct placement.

Obstruction - Thrombus, debris or impaction could block catheter patency and impair drainage. Flushes and exchanges mitigate this risk.

Over or under drainage - Incorrect pressure settings could cause elevated or lowered ICP respectively, resulting in complications. Close monitoring and adjustments as needed balances drainage.


In summary, external ventricular drains serve an important role in the management of acute hydrocephalus and intracranial hypertension. With careful surgical placement, diligent nursing care and monitoring, use of updated hardware systems, attention to infection prevention measures, and consultation with neurosurgical specialists - EVD use can effectively resolve elevated ICP while avoiding more invasive shunt surgeries until definitive treatment is established. Further advancements continue to enhance the safety and outcomes of external ventricular drainage. When utilized judiciously in appropriate clinical scenarios, EVD provides lifesaving control of elevated intracranial pressure.

Get more insights on This Topic- Global External Ventricular Drain