What Is Hydrocephalus Surgery, and How Is It Performed?

Prof. Dr. Mehmet Şenoğlu — Brain, Nerve and Spine Surgery

“Water on the brain” — this is how hydrocephalus is described among the public, and the expression creates justified anxiety in everyone who hears it. The first question my patients, or the families of the babies who receive this diagnosis, ask me is almost always the same: “Is surgery essential? Is there no other way?”

In this article, I want to explain in clear language why hydrocephalus surgery is necessary, by which methods it is performed, what its risks are, and how life takes shape after the operation.

Let me share an important fact from the very start: hydrocephalus is not a condition that resolves with medication or by waiting; however, it can be brought under control extremely successfully with an operation performed at the right time. The great majority of patients treated with modern methods live a life very close to normal.

What Is Hydrocephalus? A Brief Reminder

Our brain and spinal cord float in a clear fluid called cerebrospinal fluid (CSF). This fluid protects the brain from impacts, nourishes it, and clears away waste.

CSF is produced in the spaces within the brain called ventricles, passes through certain channels to reach the surface of the brain, and from there is reabsorbed into the blood. In other words, there is a balanced circulation system that is continuously produced and continuously absorbed.

Hydrocephalus is the disruption of this balance. It can occur through three mechanisms:

• Obstruction (obstructive): One of the channels through which the fluid passes becomes blocked. It is one of the most common causes; a congenital narrowing, a tumor, or a cyst can lead to the blockage.
• Impaired absorption: The fluid is produced but cannot be adequately absorbed. It is frequently seen after bleeding and meningitis.
• Overproduction: This is rare.

The result is the same: the fluid accumulates in the ventricles, the spaces widen, and pressure is applied to the brain tissue.

The critical point to understand here is this: the problem is not “the water itself” but the increased pressure. And the aim of surgery is to return this pressure to normal.

Symptoms: Why Does Surgery Come onto the Agenda?

Symptoms vary markedly according to age.

In Babies

Because the skull bones have not yet fused in babies, the pressure manifests itself by enlarging the head:

• Rapid enlargement of the head circumference (the most important sign)
• The fontanelle being bulging and tense
• Prominent veins on the scalp
• The “sunset sign” (the eyes constantly looking downward)
• Restlessness, constant crying, feeding difficulties, vomiting
• Regression in developmental milestones

In Children and Adults

Because the skull is closed, the pressure bears directly on the brain:

• Severe headache — especially in the mornings
• Nausea and vomiting
• Blurred vision, double vision
• Impaired balance, difficulty walking
• Drowsiness, clouding of consciousness
• A decline in school or work performance

In the Elderly: Normal Pressure Hydrocephalus (NPH)

I would like to emphasize this picture in particular, because it is most often attributed to old age or dementia and overlooked. It has three classic symptoms:

1. Gait disturbance (walking with small steps, as though the feet were stuck to the floor) — usually the first and most prominent finding
2. Forgetfulness and mental slowing
3. Urinary incontinence

When this triad is seen together, NPH should come to mind. Because, unlike dementia, NPH is a picture that can improve with surgery. When diagnosed in good time, the patient’s walking and mental functions can improve markedly.

Can Hydrocephalus Be Treated Without Surgery?

The honest answer: no. There is no permanent medical treatment for hydrocephalus. Some medications can temporarily reduce fluid production; however, this is not a definitive solution but at most a short-term bridge.

The only exception is this: if a tumor or cyst is causing the hydrocephalus, removing that mass can eliminate the obstruction and the hydrocephalus can resolve on its own.

Apart from this, the treatment is surgical, and there are two basic methods.

Method 1: Shunt Surgery (VP Shunt)

What Is a Shunt?

A shunt is a thin, flexible tube system that takes the accumulated cerebrospinal fluid from the brain and carries it to another cavity of the body where it can be absorbed. It is a well-established method that has been in use for roughly 70–75 years and has been extensively studied.

It consists of three parts:

1. The ventricular catheter: The end placed into the brain cavity.
2. The valve: The brain of the system. It regulates how much fluid passes and at what pressure. Modern programmable valves can be adjusted from outside with a magnet, without the need for an operation.
3. The distal catheter: The long end that carries the fluid.

The Most Common Type: The Ventriculoperitoneal (VP) Shunt

The fluid is directed into the abdominal cavity (the peritoneum) and is absorbed there by the body. It is the most commonly performed type.

In some situations, if the abdomen is not suitable, the fluid can be directed to the right atrium of the heart (VA shunt) or between the membranes of the lung (VPL shunt).

How Is the Operation Performed?

It is performed under general anesthesia:

1. A small incision is made in the head and a hole (a burr hole) is opened in the skull.
2. The catheter is placed into the ventricle under imaging guidance.
3. The valve is positioned under the skin behind the ear.
4. The distal catheter is passed under the skin and brought down to the abdomen.
5. Through a small incision in the abdomen, the end of the tube is left in the peritoneal cavity.

The procedure generally takes about an hour. The entire system is beneath the skin; no part is visible from the outside. After infancy, it is almost impossible to notice from the outside.

Advantages and Disadvantages of the Shunt

Advantages: It can be applied in almost every type of hydrocephalus, its effect is rapid and predictable, and there is an accumulation of experience spanning many years.

Disadvantages: There is a foreign body in the body, which brings with it the risks of infection and blockage. The patient becomes shunt-dependent for life, and revision (renewal) surgery may be needed from time to time.

Method 2: ETV (Endoscopic Third Ventriculostomy)

What Is ETV?

ETV is an endoscopic method that aims to resolve hydrocephalus without placing a shunt. Its logic is very simple: opening a new path in order to bypass the blocked one.

I explain this to my patients like so: when a water pipe becomes blocked, you have two options. Either you run a new line that bypasses the pipe (a shunt), or you open a drainage hole just before the blocked section so the water rejoins its natural flow (ETV).

How Is the Operation Performed?

1. A small incision of 1–2 cm and a hole of roughly 8–10 mm are made in the head.
2. The endoscope, which has a camera and light at its tip, is advanced from the lateral ventricle into the third ventricle.
3. A controlled opening is created in the thinned membrane at the floor of the third ventricle.
4. This opening is widened by a few millimeters with a balloon catheter.
5. The fluid can now bypass the blocked area and reach the natural absorption areas.

The procedure generally takes less time than shunt surgery, and patients are mostly discharged within a few days.

Who Is Suitable for ETV?

This is the most critical question — because ETV is not suitable for every patient with hydrocephalus.

The most suitable group: Patients with obstructive hydrocephalus. For example, aqueductal stenosis or a blockage due to a tumor.

Groups that are not suitable or have a low chance of success: Hydrocephalus due to impaired absorption, and especially babies younger than 6 months. In this age group the success rate of ETV alone is markedly low; for this reason, in some centers choroid plexus cauterization is added to ETV in an effort to increase success.

Advantages and Disadvantages of ETV

Advantages: No foreign body remains in the body; the risks of shunt-related infection, blockage, and revision disappear. When it succeeds, the patient lives a “shunt-free” life.

Disadvantages: It cannot be applied to every patient. There is a possibility that the opening created will close over time; in this case, a repeat ETV or a shunt may be required. If it fails, a shunt may still be needed.

Shunt or ETV? How Is the Decision Made?

When making this decision, we look at the following elements:

• The type of hydrocephalus: Obstruction or impaired absorption?
• The location of the blockage: Is the anatomy suitable for ETV?
• The patient’s age: ETV success is low especially in babies under 6 months.
• The underlying cause: Bleeding, infection, tumor?
• The anatomy of the ventricles: Is there a structure through which the endoscope can advance safely?

The general approach is this: in a suitable patient, ETV is the first choice, because it leaves no foreign body in the body. However, there is a large group of patients who are not suitable for ETV, and for them the shunt is still the most reliable solution.

Here I would like to emphasize one thing: the shunt is not the “old” method and ETV the “new and better” one. The two are solutions to different problems. An ETV applied to the wrong patient fails and costs time.

Risks and Complications

One must be honest: like every surgical procedure, these operations too have risks.

Risks Common to Both Methods

• Bleeding
• Infection
• Anesthesia-related risks
• Seizure

Risks Specific to the Shunt

• Shunt infection: The most serious complication; it is generally seen in the first months. An infected shunt must be removed and, after treatment, a new one placed.
• Shunt blockage: The most frequently seen problem; it manifests with the symptoms of shunt malfunction and requires revision surgery.
• Overdrainage: Too much fluid draining away; it can cause headache (especially one that increases on standing up) and, rarely, bleeding inside the head. Programmable valves reduce this risk.
• Fracture or displacement of the catheter: Especially in children, due to growth.
• Problems related to the abdominal region.

Risks Specific to ETV

• Closure of the opening (stoma closure): The most frequently seen late complication; it occurs in a proportion of patients and may require a repeat procedure.
• Injury to neighboring structures during the operation (rare, but it requires experience)
• Temporary hormonal or memory-related problems (rare)
• The need to switch to a shunt if ETV fails

After the Operation: What to Watch For

In Hospital

The patient is closely monitored in the early period; the state of consciousness, vomiting, headache, and — in babies — the fontanelle are followed. With follow-up imaging, it is confirmed that the ventricles have decreased in size and that the system is working correctly. The length of hospital stay varies according to the method and the patient’s condition.

At Home: Know the Signs of Shunt Malfunction

This section is the most important piece of information a patient with a shunt, or their family, needs to memorize. The following symptoms indicate that the shunt may have become blocked or infected, and you must go to the nearest emergency department without losing any time:

In babies:

• The fontanelle bulging and becoming tense
• The head circumference beginning to enlarge rapidly again
• Constant restlessness, refusing to feed
• Vomiting, drowsiness, the “sunset” gaze

In children and adults:

• A progressively increasing headache, especially in the mornings
• Nausea and projectile vomiting
• Drowsiness, clouding of consciousness
• Visual disturbance, double vision
• Impaired balance, difficulty walking
• Changes in personality and behavior
• Fever and redness or swelling along the shunt tract (a sign of infection)
• A seizure appearing for the first time

Do not wait with these symptoms. Shunt malfunction is easily resolved when addressed in good time; when delayed, it can lead to serious consequences.

Living With a Shunt: How Is Daily Life Affected?

This is the subject families are most curious about, and it generally has a far more reassuring answer than expected.

Patients with shunts can go to school, work, travel, marry, and have children. The system is entirely beneath the skin and is not visible from the outside.

A few practical points:

• Sport: Activities such as swimming, walking, and running are generally unrestricted. Boxing, martial arts, and contact sports with a high risk of blows to the head are not recommended.
• Airports and MRI: In patients with a programmable valve, an MRI scan can alter the valve setting; after an MRI, the valve needs to be checked and, if necessary, readjusted. For this reason, always state that you have a shunt before any imaging.
• Carry a card: I recommend carrying an information card showing your shunt type, valve setting, and operation date. It is very useful in an emergency.
• Regular check-ups: Even if you have no complaints, attend your check-ups at the intervals your doctor recommends.

Frequently Asked Questions

Below, I have gathered the most frequently asked questions on this subject along with brief answers. These answers are for general information; the information that applies to your specific situation is the one given by the doctor who examines you or your relative.

How is hydrocephalus surgery performed?

There are two basic methods. In shunt surgery, a catheter is placed into the brain cavity through a small hole made in the skull; a tube passing under the skin transfers the fluid, usually into the abdominal cavity. In ETV, an opening is created endoscopically in the floor of the third ventricle, allowing the fluid to bypass the blocked area. Which one is appropriate is determined by the type of hydrocephalus and the patient’s age.

Does hydrocephalus resolve without surgery?

No. There is no permanent medical treatment for hydrocephalus. The only exception is that if a tumor or cyst is causing the hydrocephalus, removing that mass can resolve the picture. Apart from this, the treatment is surgical.

How long does shunt surgery take, and how long is the hospital stay?

Shunt surgery generally takes about an hour; ETV is shorter. The length of hospital stay varies according to the method, the age, and the patient’s general condition; only the team following you can tell you the exact duration.

Does the shunt stay for life, or is it removed?

In most patients, the shunt remains for life and the patient becomes shunt-dependent. When the shunt becomes blocked or infected, revision (renewal) surgery is required. In some patients — especially when ETV is successful — a shunt may never be needed at all.

Can a patient with a shunt live a normal life?

Yes. The shunt is entirely beneath the skin and is not visible from the outside. Patients can go to school, work, travel, and do sports. It is only necessary to avoid contact sports such as boxing that carry a high risk of blows to the head.

Which is better, ETV or a shunt?

Neither is “better” than the other; they are solutions for different situations. In obstructive hydrocephalus, in a suitable patient, ETV is the first choice, because it leaves no foreign body in the body. However, in hydrocephalus due to impaired absorption, and especially in very small babies, the chance of ETV succeeding is low; in these patients, the shunt is a more reliable solution.

How do I know if the shunt is blocked?

A progressively increasing headache (especially in the mornings), nausea and vomiting, drowsiness, clouding of consciousness, and visual and balance problems are the main symptoms. In babies, a bulging fontanelle, restlessness, and vomiting are notable. With these symptoms, go to the emergency department without losing any time.

What are the risks of hydrocephalus surgery?

Bleeding, infection, seizure, and general anesthesia-related risks apply to both methods. Specific to the shunt are infection, blockage, overdrainage, and catheter problems; specific to ETV are closure of the opening created and injury to neighboring structures (rare).

Does the hydrocephalus seen in the elderly (NPH) improve with surgery?

In normal pressure hydrocephalus, gait disturbance, forgetfulness, and urinary incontinence are seen together. In suitable patients, shunt surgery can provide marked improvement — especially in the gait disturbance. This is a picture that needs to be distinguished from dementia and that is treatable; for this reason, a correct diagnosis is very valuable.

A shunt was placed in my baby — will it need to be changed as they grow?

In modern shunt systems, because the distal catheter is left long, lengthening it as the child grows is most often not required. However, revision may be needed over time due to blockage, fracture, or displacement. This is why regular follow-up is important.

Disclaimer (Legal Notice)

The information contained in this article has been prepared for general informational purposes only and in no way replaces a medical examination, diagnosis, or treatment. The type of hydrocephalus, the decision to operate, the method to be applied (shunt or ETV), the risks, and the recovery process vary greatly according to the patient’s age, the cause of the hydrocephalus, and their general state of health, and can only be determined by a team of doctors who evaluate you or your relative. For any decision regarding diagnosis and treatment, always consult a specialist physician. If symptoms suggesting shunt malfunction (increasing headache, vomiting, drowsiness, clouding of consciousness, a bulging fontanelle in babies, fever) are present, go to the nearest emergency department without losing any time.