Shunts and hydrocephalus surgery
A shunt is a thin tube with a valve that drains excess cerebrospinal fluid from the brain to the abdomen, placed under general anaesthetic through a small incision behind the ear. Where the diagnosis is unclear, overnight pressure monitoring confirms whether a shunt is needed before anything is implanted.
Greenslopes Private Hospital, Brisbane
Watkins Medical Centre, Spring Hill, or telehealth
A current GP or specialist referral is needed
At a glance
Shunt insertion, endoscopic third ventriculostomy, cyst fenestration, pressure monitoring.
General.
Shunt surgery usually takes about an hour.
One to three days for a shunt; two to three nights for pressure monitoring.
A shunt is reviewed for life, in children and adults.
What the procedures involve
All of these procedures deal with the flow of cerebrospinal fluid. Which one applies depends on the cause of the problem and on how certain the diagnosis is.
A ventriculoperitoneal shunt has three parts: a fine catheter placed into one of the fluid chambers of the brain through a small opening in the skull behind the hairline; a valve, sitting under the scalp, that opens at a set pressure; and a long tube tunnelled under the skin of the neck and chest to the abdomen, where the fluid is absorbed. Most valves used now are programmable, so the pressure setting can be adjusted at the rooms with a magnet rather than by another operation.
An endoscopic third ventriculostomy is an alternative for hydrocephalus caused by a blockage. Through a keyhole opening, an endoscope is passed into the fluid chamber and a small hole is made in its floor so that fluid can bypass the blockage into the normal spaces around the brain. There is no hardware left behind. It suits some anatomy and not others, which the MRI shows.
Cyst fenestration opens the walls of an arachnoid cyst, endoscopically or through a small craniotomy, so that its fluid joins the normal circulation. Where the diagnosis of hydrocephalus is uncertain, particularly in normal pressure hydrocephalus, a fine pressure probe is placed under the scalp and the pressure is recorded overnight, or a lumbar drain is left in for a few days to see whether walking improves, so that a shunt is only implanted when the evidence supports it.
Before and during the procedure
Shunt surgery is a short operation. The decision that leads to it often takes longer, and that time is well spent.
- Imaging to confirm the size of the fluid chambers and the cause; for NPH, a drainage trial or overnight monitoring where the picture is uncertain
- Blood-thinning medication stopped on the anaesthetist’s instructions
- Fasting from midnight; admission on the day of surgery
- A small area of hair clipped behind the ear; two further small incisions at the neck or chest and the abdomen
- A CT or X-ray after surgery to confirm the position of the tubing
- Your next of kin is telephoned after the operation
Children
Children with hydrocephalus are treated at the Queensland Children’s Hospital. The same procedures apply, and a shunt placed in infancy is reviewed as the child grows, since the tubing may need lengthening and the valve setting may need to change.
Planning is done on your own imaging, and the operation is only booked once you have had time to think.
Recovery and risks
Most people are home within a few days. The longer-term matter is living with a shunt and knowing when something is wrong.
The wounds are small and heal within two weeks. Headache from the change in pressure is common in the first days and usually settles; if it persists, the valve setting is adjusted at the rooms. In normal pressure hydrocephalus, walking often improves within days and memory more slowly over weeks; not every symptom responds, and this is discussed beforehand. After an endoscopic third ventriculostomy the stay and recovery are similar, and the follow-up MRI shows whether the new opening is working.
A shunt is reviewed at the rooms and then as needed rather than on a fixed schedule; scans are done when symptoms suggest a problem. Carry a note of the shunt type and setting, because some valves need checking or resetting after an MRI. Headache, vomiting, drowsiness, fever or redness along the tubing at any time in the future should be taken to an emergency department, since they can mean the shunt has blocked or become infected.
Risks that are discussed with you
- Shunt blockage, at any time in the future, needing revision surgery; this is the most common problem with shunts
- Infection of the shunt, usually in the first months, treated with antibiotics and temporary removal of the shunt
- Over-drainage, causing low-pressure headache or, rarely, bleeding over the surface of the brain; adjusted by changing the valve setting
- Bleeding along the catheter track, or injury to the brain where the catheter passes; uncommon
- Abdominal problems from the lower end of the tubing; uncommon
- For an endoscopic third ventriculostomy: the opening closing over, or injury to structures near the floor of the ventricle
- For NPH: the symptoms not improving as hoped, despite a working shunt
Every operation carries risks, and the risks of brain surgery are discussed with you in detail, in person, before you decide. The list here is general and is not a substitute for that conversation.
Alternatives
The main alternatives are a different procedure, or no procedure.
- ObservationStable, compensated hydrocephalus and most arachnoid cysts are watched with scans and review rather than treated.
- Endoscopic third ventriculostomyWhere the anatomy suits it, this avoids a shunt altogether, with no hardware and none of the long-term shunt problems.
- Treating the causeA tumour or cyst that is blocking the fluid pathways may be removed, resolving the hydrocephalus without a shunt.
- A different shunt routeOccasionally the fluid is drained to the chest cavity or to the heart instead of the abdomen, when the abdomen is not suitable.
Which of these applies to you depends on your condition and your circumstances. The alternatives are set out at the consultation on equal terms with surgery, and nothing is booked until you have had time to think.
Dr Gert TollessonNeurosurgeon, Brisbane
Ready to talk it through?
A current referral is needed to book. If you do not have one yet, call the rooms on (07) 3870 3708 and they will explain what to ask your GP for.
Request a consultation
Send your details and the rooms will call you to arrange a time. Referrals are triaged as they arrive.
Monday to Friday, 8:30am to 4:30pm. No referral yet? The rooms will explain what to ask your GP for.
Before your appointment
What happens from referral to follow-up, and what it costs.