Endoscopic Third Ventriculostomy (ETV)

What Is It?

Endoscopic third ventriculostomy is a type of treatment for some forms of hydrocephalus. It involves making a small opening in the floor of the third ventricle, one of the fluid-filled spaces within the brain, which opens it up to the space surrounding the brain. This allows cerebrospinal fluid to be diverted from within the ventricles to the area outside the brain.

ETV is a relatively new treatment for hydrocephalus. It is performed through a device called an endoscope. The endoscope is a long tube with a camera lens at the end which allows the surgeon to visualize inside the head. The endoscope is placed through a small opening in the skull, through the brain, into the ventricles (the fluid-filled spaces within the brain). After being maneuvered into the third ventricle, instruments passed through the endoscope are used to make a small opening in the floor of the ventricle. The surgeon performs this operation while watching a video monitor which displays the view from the endoscope inside the ventricles.

Traditionally, hydrocephalus, which is thought to arise from derangement of the normal flow and/or absorption of cerebrospinal fluid in and around the brain and spinal cord, has been treated by diversion procedures which shunt the fluid from the brain to another area where it can be absorbed. The most commonly used procedure of this type is a hydrocephalus shunt which diverts fluid through a catheter and valve to the abdominal cavity, where it can be re-absorbed. Because this requires leaving a catheter and valve within the patient, these procedures can be prone to infection as well as malfunctioning such as clogging and may require re-operation for revision or replacement.

The endoscopic third ventriculostomy, if appropriate, is sometimes thought to be preferable because it does not leave any foreign body or mechanical device inside the patient. However, they are not effective in every patient with hydrcephalus and can fail themselves as well, often requiring another type of hydrocephalus shunt for definitive treatment.


What Is It Used For?

Endoscopic third ventriculostomy is most commonly considered for the treatment of obstructive hydrocephalus. Because it only diverts fluid from inside the ventricles to the space around the brain, it requires that the flow and absorption in that space is normal enough to absorb this re-directed fluid. In many cases of communicating hydrocephalus this ability to re-absorb fluid is not functional and therefore an ETV will not effectively treat the hydrocephalus.

Therefore, ETV is often used for various forms of obstructive (non-communicating) hydrocephalus such as aqueductal stenosis or hydrocephalus due to obstruction by a tumor. For non-obstructive forms of hydrocephalus such as idiopathic normal pressure hydrocephalus, some forms of congenital hydrocephalus and hydrocephalus secondary to meningitis or subarachnoid hemorrhage, a hydrocephalus shunt procedure is most commonly used. While an ETV may be effective in a subset of these patients, there is controversy about its use for these pathologies.

The indications for endoscopic third ventriculostomy are clearly complex and highly patient-specific so generalizations cannot be made. Each patient should discuss the treatment options for their hydrocephalus with their own treating physicians.



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Important Note: This site is not intended to offer medical advice. Every patient is different, and only your personal physician can help to counsel you about what is best for your situation. What we offer is general reference information about various disorders and treatments for your education.

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