ETV and ETV with CPC

ETV Surgery Versus a Shunt

A shunt system is a commonly used method to treat hydrocephalus and involves draining excess cerebrospinal fluid (CSF) from the brain into other parts of the body where it can be absorbed. A shunt system requires the surgical implantation of a tube, followed by lifelong monitoring and management by a healthcare professional.

For some individuals with hydrocephalus, there are two additional alternatives to a shunt system. These treatments are:

1. Endoscopic third ventriculostomy, or ETV; and
2. Endoscopic third ventriculostomy with choroid plexus cauterization, known as ETV/CPC. This procedure is primarily used in children under two.

It’s important to note that both of these options treat hydrocephalus but neither cures the condition, and not all individuals are good candidates for these treatment options.

Endoscopic Third Ventriculostomy Procedure for Hydrocephalus

Endoscopic Third Ventriculostomy (ETV) is a hydrocephalus treatment option that involves creating a small opening in the ventricular system to drain excess fluid. ETV can treat hydrocephalus without the need for an implanted shunt tubing by providing a natural internal pathway for CSF to flow and be reabsorbed.

The Goal of ETV Surgery

The goal of an ETV is to drain the excess fluid to avoid a shunt placement.

It may be considered an option in the following instances:

1. As the initial treatment
2. After a shunt has failed or
3. In some cases, in conjunction with an existing shunt system.

Who is Eligible for an ETV?

ETV is typically used for adults and children over the age of 2 with non-communicating hydrocephalus (also known as obstructive hydrocephalus) which is caused by a blockage in the brain, like aqueductal stenosis; however, it may also be useful in other cases.

To determine if ETV is a good option, doctors will use MRI scans to access eligibility.

How is the Procedure Performed?

When performing the ETV procedure, the neurosurgeon:

1. Makes a small incision on the scalp
2. Drills a small hole (burrhole) in the skull
3. Guides an endoscope—a long, thin tube with a camera on the end—through the brain into one of the lateral ventricles
4. Passes the endoscope down into the third ventricle
5. Punctures the membrane on the floor of the third ventricle to create an opening
6. Removes the endoscope and closes the wound

The opening allows CSF to exit the ventricle system and flow in and around the brain as it would under normal circumstances. Learn more about what to expect with ETV surgery.

What are the Possible ETV Complications?

There are some complications to watch for including fever, bleeding, infection, and a sudden pathway closure.

Ideally, ETV is a one-time procedure, but evidence shows an ETV can fail and may need to be repeated. You should have a candid conversation with your physician about the expected outcomes and likelihood of success with ETV.

Endoscopic Third Ventriculostomy with Choroid Plexus Cauterization Procedure (ETV/CPC)

While ETV is an effective treatment for hydrocephalus in some people, it may not be sufficient on its own. An additional hydrocephalus treatment option combines ETV with a surgical procedure known as choroid plexus cauterization, or CPC.
The ETV/CPC procedure reduces the choroid plexus—the tissue that produces CSF in two of the four ventricles inside the brain. This combination decreases the amount of fluid produced and may also reduce the strength of pulses that can cause the ventricles to enlarge, helping to relieve pressure on the brain.

Note: This treatment is primarily used in infants as an alternative to shunting.

What are the Benefits of ETV/CPC Surgery?

The treatment, known as ETV/CPC, generally improves the outcomes of ETV in an infant’s brain. Combining the two treatments – basically opening a ventricle to allow CSF to flow and, at the same time, minimizing how much fluid is produced – is an effective way to treat hydrocephalus.

Learn more about Choroid Plexus Cauterization surgery.

Who is Eligible for ETV/CPC Surgery?

ETV/CPC is primarily used in children under the age of 2 with types of hydrocephalus caused by:

• Congenital aqueduct stenosis
• Dandy-Walker malformation
• Spina bifida
• Encephalocele
• Ventricular infections
• Congenital communicating

What Happens during the ETV/CPC Procedure?

When performing the ETV/CPC surgery:

1. The neurosurgeon first completes the ETV procedure as described above.
2. CSF fluid then flows normally through the opening and into the space surrounding the surface of the brain.
3. The neurosurgeon passes specialized surgical instruments through a flexible endoscope and cauterizes, or burns, the choroid plexus in two of the four brain ventricles, the lateral ventricles. The cauterization reduces the tissue’s ability to produce CSF. To gain access to both lateral ventricles, the surgeon often needs to open the midline septum (connective tissue between the two lateral ventricles) as part of the procedure. At times, the septum has already opened as part of the dilation of the ventricles over time.
4. Once the choroid plexus has been sufficiently cauterized, the surgeon carefully removes the endoscope and closes the wound.

What are the Possible Complications?

Bleeding, usually mild, is the most frequent complication of ETV/CPC, and may occur during or after surgery.

Following surgery, the most common complication is the closure of the pathway that is surgically created with ETV and infection.

See more detailed information about potential ETV Complications.

What Does ETV Treatment Success Look Like?

It may take some time for CSF to be reabsorbed, which means it may be difficult to determine success right after ETV or ETV/CPC surgery.

The results of ETV are determined by:

• Assessing clinical signs of raised intracranial pressure in older children and adults; and
• Assessing the rate of head growth by serial head circumference measurements and assessing the fontanelle tension in infants.

Ultimately, the treatment is considered successful if:

1. The intracranial pressure (ICP) normalizes;
2. The brain’s ventricles stay the same size or get smaller; and
3. A shunt system is not required after the treatment.

Success rates vary based on the patient’s age and the cause of their hydrocephalus.

For some patients, the chance for success of the ETV may be up to 90%. It’s important to note that ETV or ETV/CPC may not be recommended for some patients because they have a lower chance for a successful outcome.

What Does ETV Surgery Failure Look Like?

ETV or ETV/CPC is considered unsuccessful if:

1. The patient cannot absorb the CSF, causing the ventricles to get larger; or
2. The brain’s pathways develop a block that keeps the CSF from freely flowing.

Most unsuccessful procedure patients will become shunt dependent.

Learn more about ETV and ETV/CPC by viewing a session from our National Conference on Hydrocephalus below. (Note: The ETV and ETV/CPC Section begins at minute: 15:28)

Information you can trust! This article was produced by the Hydrocephalus Association, copyright 2024. We would like to thank the following individuals for their valuable contributions and expert input: Abhaya Kulkarni, MD, PhD, FRCSC, and William E. Whitehead, MD, MPH.