ETV and ETV with CPC
Endoscopic Third Ventriculostomy (ETV)
A second treatment option for hydrocephalus is a surgical procedure called endoscopic third ventriculostomy (ETV). This is typically used for children over the age of 2 with non-communicating hydrocephalus; hydrocephalus caused by a blockage in the brain like aqueductal stenosis.
In the ETV procedure, a small hole called a burrhole is made in the skull and an endoscope is gently guided through the brain into one of the lateral ventricles. With the use of a camera, the endoscope then passes down into the third ventricle and punctures the membrane on the floor of the third ventricle. This creates an alternative pathway for CSF to flow out of the ventricles and around the brain. This approach is an important alternative to shunting for obstructive hydrocephalus and may be useful in other cases as well.
Not everyone is a candidate for ETV treatment. Learn more, watch our video.
The ultimate goal of ETV is to render a shunt unnecessary. Although ETV is ideally a one-time procedure, evidence suggests that some people may require more than one surgery to be successful. It’s important to note, ETV is not a cure for hydrocephalus, but rather an alternate treatment.
Endoscopic Third Ventriculostomy with Choroid Plexus Cauterization (ETV/CPC)
The third treatment option involves an ETV with the addition of a procedure called choroid plexus cauterization (CPC). This treatment is primarily used in children under 2. Once inside the brain, the neurosurgeon uses a device to burn or cauterize choroid plexus tissue to reduce the amount of fluid being introduced into the ventricles. The choroid plexus is vascular tissue within the ventricles of the brain and is the source of CSF production. The fluid then passes normally through the opening made during the ETV and into the space surrounding the surface of the brain. Not everyone is a candidate for ETV/CPC treatment. ETV/CPC is a very technical surgery and should be performed by a neurosurgeon trained and experienced in the procedure.
Learn more, watch our video.
How is Success Defined?
“Success” in terms of this procedure is usually considered (by patients and doctors alike) to be avoiding a shunt in a patient who would otherwise require one. Most doctors would categorize ETV as successful if a person later shows clinical evidence of normal intracranial pressure (ICP) and structural evidence of stable or decreased ventricular size. If someone was previously shunted, the shunt must be either removed or proved nonfunctional to demonstrate success.
The success rate for ETV or ETV/CPC depends upon patient factors such as age, cause of hydrocephalus, and whether there is scarring in the fluid space below the floor of the third ventricle (subarachnoid pathway). For some patients, the chance for success of the ETV may be up to 90%; however, for others, ETV or ETV/CPC may not be recommended because the chances for success are sufficiently low.
The results of ETV are determined by assessing clinical signs of raised intracranial pressure, head circumference measurements, and fontanelle tension, as well as by MRI/CT scans. It is important to note that, in some cases, ventricles may remain large, in spite of a return to normal intracranial pressure.
Most failed ventriculostomy patients will remain shunt dependent. Doctors attribute failed procedures to a patient’s inability to absorb the CSF or a block in the subarachnoid pathways. Because CSF reabsorption pathways might require some time to normalize following ventriculostomy, it may not be possible to determine success immediately after the operation.
Your neurosurgeon should be able to provide you with a reliable estimate of the likelihood of success in your particular situation prior to the operation. It’s critical that parents and patients understand that ETV is not always a permanent cure for hydrocephalus. Candid communication with your physician regarding the definition of success is important when considering ETV.
Information you can trust! This article has been reviewed by members of our Medical Advisory Board and other professionals in the field.