How hydrocephalus is treated today

An overview of treatment options

Hydrocephalus treatment has two main goals: take pressure off the brain by removing or rerouting excess cerebrospinal fluid, and treat the underlying cause when there is one (for example, a tumor or an infection).

Two surgeries do most of the work of moving fluid:

• A shunt is a small implanted device that drains CSF from a ventricle to another part of the body where the fluid can be safely absorbed.
• An endoscopic third ventriculostomy (ETV) creates a new pathway for CSF inside the brain itself, with no implanted device.

The right option depends on the type of hydrocephalus, the patient's age, the cause, and the anatomy of the brain. Both surgeries are done by neurosurgeons. In children, this means pediatric neurosurgeons.

Shunts

A shunt has three main parts:

• A proximal catheter — a soft, thin tube placed into one of the ventricles inside the brain
• A valve — a small one-way device, just under the scalp, that controls how much CSF moves and in which direction
• A distal catheter — a longer tube that runs under the skin to another part of the body where the fluid can be absorbed

Shunts are named for where the distal catheter ends:

• Ventriculoperitoneal (VP) shunt — drains to the abdomen. This is by far the most common type.
• Ventriculoatrial (VA) shunt — drains to a large vein near the heart.
• Ventriculopleural shunt — drains to the space around a lung.
• Lumboperitoneal (LP) shunt — drains from the spinal canal in the lower back to the abdomen. Used for some communicating cases, including some NPH.

Shunt valves and how they're set

The valve is what makes a shunt work. It opens and closes to keep CSF moving at the right rate. Two main valve types are used today:

• Fixed-pressure valves open at a single preset pressure. The setting cannot be changed once the valve is implanted.
• Programmable valves can be adjusted by a clinician using a magnet placed against the scalp. This lets the surgeon fine-tune the drainage without another surgery.

Some shunts also include an anti-siphon device, which helps prevent too much fluid from draining when the patient stands up.

Programmable valves can be affected by strong magnetic fields. Older designs sometimes shifted their setting during MRI scans, which meant the valve needed to be re-set after every scan. Newer MRI-safe designs hold their setting through 3T MRI fields. Our lab's research has documented which programmable valves remain stable in these conditions.

Endoscopic third ventriculostomy (ETV)

An ETV uses a small camera (an endoscope) passed through a small hole in the skull to create a new opening in the floor of the third ventricle. This gives CSF a way to bypass a blockage further down the normal pathway.

ETV has a few advantages over a shunt:

• No implanted device is left behind
• No catheter that can break, block, or get infected over time
• When it works, patients may avoid the cycle of revisions that comes with long-term shunt care

ETV also has clear limitations. It is most effective for obstructive (non-communicating) hydrocephalus, and even then it does not work for every patient. Success rates vary by age and cause. ETV can also fail later — sometimes years after the original procedure — if the opening closes off.

In infants and in settings where shunt care is hard to access, ETV is sometimes combined with cauterization of the choroid plexus (the structure that produces CSF) to improve success. This combined procedure is called ETV + CPC.

What surgery is like

Both shunt placement and ETV are done in an operating room under general anesthesia. The hair around the surgical site is clipped (not usually shaved). The procedure itself typically takes an hour or two.

For a shunt, the surgeon makes a small incision on the scalp and a small hole in the skull to pass the proximal catheter into the ventricle. The valve sits just under the scalp. The distal catheter is tunneled under the skin to its destination (most often the abdomen, where a small additional incision is made).

For an ETV, the surgeon makes a small incision and a small hole in the skull, then passes an endoscope through the brain to the third ventricle and creates the new opening.

Most patients stay in the hospital for one to a few days. Pain after surgery is usually managed with standard medications. The full incisions heal over a few weeks.

Recovery and long-term follow-up

Recovery from the surgery itself is typically straightforward. The longer-term care matters more.

People who have had a shunt placed — and the families of children with shunts — generally have:

• Periodic follow-up visits with the neurosurgery team
• Imaging from time to time (often MRI, sometimes ultrasound for babies)
• A clear plan for how to reach the team if symptoms change
• A copy of the shunt details — what type, what valve setting, what date it was placed — to give to other clinicians when needed

For patients after ETV, follow-up is similar: visits, periodic imaging, and a plan in case symptoms return.

When a shunt needs revising

Shunts are reliable devices, but they are not permanent. Over a lifetime, many shunts need to be revised — meaning all or part of the system is replaced. The most common reasons are:

• Blockage, where part of the catheter clogs and CSF stops flowing
• Disconnection or breakage, where the tubing comes apart or breaks
• Infection, especially in the first months after placement
• Over-drainage or under-drainage, where the valve setting doesn't match what the patient needs
• Growth in a child, where the distal catheter eventually becomes too short

Revision rates are higher in children than in adults, and higher in the first year after a shunt is placed than later. Research on better placement, better valves, ways to detect failure earlier, and ways to reduce infections is part of why this initiative invests in shunt technology alongside the medication-based work.

Outcomes

Many people with treated hydrocephalus live full lives. They go to school, work, raise families, and participate in activities they care about. Outcomes vary widely, and several factors affect them:

• The cause and type of hydrocephalus
• The age at which it began
• How much time passed before treatment
• Whether complications have occurred
• The quality and continuity of long-term care

Outcomes for NPH depend heavily on early recognition. Patients identified and treated earlier tend to do better than those whose NPH has been progressing for years.

What we're working on

Both ongoing streams of our research aim to make life better for people with hydrocephalus:

• Shunt technology research works on the problems above — better placement, fewer infections, earlier detection of shunt failure, safer follow-up imaging.
• Pathophysiology research works on the longer-term question: can we one day treat hydrocephalus with medication, as an alternative to surgery for some patients? Read more about our research approach →

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