ETV Complications

Hydrocephalus can be treated by undergoing a surgical procedure called Endoscopic Third Ventriculostomy (ETV) or Endoscopic Third Ventriculostomy with Choroid Plexus Cauterization (ETV/CPC). The ETV/CPC procedure is only available to infants.

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. For some patients, the chance for success of the ETV may be up to 90%; however, for others, ETV – with the addition of CPC for infants – may not be recommended because the chances for success are sufficiently low. Your neurosurgeon should be able to provide you with a reliable estimate of the likelihood for success in your particular situation prior to the operation.

The most common complication with these two procedures is the closure of the pathway that is surgically created with ETV and infection.

Sudden Pathway Closure with ETV

Sudden closure of the pathway created using Endoscopic Third Ventriculostomy (ETV) can be sudden and life-threatening. Pathway closure occurs in 20 to 50% of patients within five years of the procedure with the great majority of treatment failures occurring within the first six months of the operation. Although late failures can occur, they are rare, and the ongoing risk of treatment failure over subsequent years is much less than that for patients with shunt-dependence.

It’s critical that parents and patients understand that ETV is not a permanent cure for hydrocephalus. Candid communication with your physician regarding the definition of success is important when considering ETV.

Infection with ETV and ETV/CPC

Infection usually occurs in less than one percent of those treated surgically with ETV or ETV/CPC procedures.

Potential Complications with ETV and ETV/CPC

With new technologies the risks of ETV have been minimized, however, there are still potential complications, including fever, infection, and bleeding. Attempts to perforate or create an opening in the ventricular floor can lead to bleeding, as can damage to ventricular walls, the upper brain stem or perforation of the basilar artery. Significant bleeding due to vessel injury beneath the floor of the third ventricle can be catastrophic, but it is rare.

Other complications from ETV include short-term memory loss, since the procedure may affect the hypothalamus and the areas of the mammillary body which are responsible for memory. Endocrinologic irregularities can occur following ETV and ETV/CPC as a result of the small opening in the area of the third ventricle which is responsible for some hormonal function. Fortunately, these complications are often short-lived. However, in unusual circumstances, these complications may be permanent.

Most Common Tests to Determine ETV Complications

It is critical that your doctor diagnose and treat an ETV complication immediately. Complications are diagnosed through the following tests listed below.

Computed tomography (CT scans) is a reliable procedure for diagnosing and assisting in the management of hydrocephalus. It is a sophisticated technique in which x-ray beams are passed through a patient’s body and pictures of the internal structures, in this case, the brain, is made by the computer.

CT scans do use radiation, raising concerns about exposure, particularly for hydrocephalus patients who rely on CT scans and MRIs multiple times over their lives as critical tools to determine if there is a problem with a current treatment. New machines as well as new techniques that reduce the number of images captured limit the amount of radiation exposure to a patient. You may hear terms like low dose and/or rapid acquisition CT scans. In general, it is better to limit the amount of radiation to the minimal amount needed. However, this should not come at the expense of your safety. Know the CT techniques used at your hospital, particularly the emergency room. If a CT scan is ordered, it is fine to speak to your doctor about the urgency of the situation and whether or not waiting for an MRI is possible.

Magnetic Resonance Imaging (MRI), like the CT scan, is a diagnostic technique that produces images of the brain—but unlike CT scanning, MRI does not use x-rays/radiation. Instead, MRI uses a very powerful magnet to scan the patient, and the magnetic signals create images that can be read by a computer. MRI is a painless procedure and has no known side effects. There are two types of MRI scans: The Single Shot Fast Spin Echo (also called a ‘quick brain MRI), which takes about three minutes and rarely requires sedation, is used to assess ventricular size. The full MRI, which takes 30 to 60 minutes and may require sedation, shows more minute details. Before the longer scans are performed, small children are given a sedative to minimize movement that would cause blurring of the images.

The radiologist will review the scans, write a report, and send the report on to the doctor.

Signs and Symptoms of ETV Complications

When things are going well, it’s easy to put the concerns about hydrocephalus and the complications that come with it out of your mind. However, it’s critical to understand the signs and symptoms of a closure of an ETV. Seeing your physician or visiting the Emergency Department, even if symptoms are not ultimately related to hydrocephalus, the ETV or ETV/CPC is the right choice. Seeking immediate medical attention can identify a resolvable complication and enable you or your family member to avoid brain damage or even death, especially in children.

Symptoms of an ETV closure vary considerably from person to person, but recurring failures tend to have similar symptoms for a particular person. When an abrupt malfunction occurs, symptoms can develop very rapidly potentially leading to coma and possibly death. In infants and toddlers, it’s important to be aware that medication with a side effect of drowsiness can mimic or mask signs of ETV closure and should be used with caution in those with hydrocephalus, especially infants and young children.

Infants

• Enlargement of baby’s head
• Fontanel full and tense when an infant is upright and quiet
• Prominent scalp veins
• Vomiting
• Sleepiness
• Irritability
• Downward deviation of eyes
• Less interest in feeding
• Fever, potentially present with ETV infection

Toddlers

• Enlargement of head
• Vomiting
• Headache
• Sleepiness
• Irritability
• Loss of previous abilities (sensory or motor function)
• Fever, potentially present with ETV infection

Children and Adults

• Vomiting
• Headache
• Vision problems
• Irritability and/or tiredness
• Personality change
• Loss of coordination of balance
• Difficulty waking up or staying awake (this symptom requires urgent attention as it can potentially lead to a coma)
• A decline in academic or job performance
• Fever, potentially present with ETV infection

Older Adults with Normal Pressure Hydrocephalus

People who are diagnosed and treated in adulthood, including those with NPH, tend to revert to the symptoms they experienced before initial treatment when they are experiencing a malfunction.

• Difficulty walking/Gait disturbances
• Cognitive challenges/Mild dementia
• Urinary Urgency or incontinence
• Fever (a sign of ETV infection)

Information you can trust! This article was produced by the Hydrocephalus Association, copyright 2021. We would like to thank Marion L. (Jack) Walker, MD for his valuable contribution and expert input.