What are the treatment options for hydrocephalus?
Treatment may involve treatment of the cause of the hydrocephalus, i.e. removal of a tumour which may be blocking the fluid chambers. Most patients with symptomatic hydrocephalus need a cerebral spinal fluid (CSF) diversion procedure. The options are to divert the fluid from the head into another body cavity (abdomen or chest) or re-route the flow of fluid within the brain.
Hydrocephalus is often a difficult problem to treat. With changes in technology of the valves, anti-bacterial catheters and endoscopes the treatment is improving. Our view is that patients with hydrocephalus must be managed by a team who specialise in the treatment of these particular patients. Experience in treating the disease, experience in shunt insertion and experience in endoscopy all improve the results for the patients.
A Diversion procedure is performed by inserting a tube and a valve into the fluid chambers of the brain and then running a further tube from the valve into the appropriate body cavity. This system is called a shunt, and is most commonly placed from the ventricle to the abdomen (ventriculo-peritoneal shunt).
There are many different shunts available. In simplistic terms a shunt is a tube running from the ventricle attached to a valve and then into the abdomen. When the fluid volume in the brain increases, the valve opens and fluid drains away, leaving the pressure in the brain at a normal level.
Some patients drain too much fluid or too little fluid. These patients can benefit from a programmable shunt when the opening pressure can be altered.
Complications of Shunts
Shunts can become infected (2%-5%) and can block. 80% of shunts will cease to function within 20 years. Complications can also arise from over drainage, and some of these may be avoided by programmable valves. If the shunt ceases to function then a replacement will be needed.
In some cases of hydrocephalus fluid can be re-routed within the brain. A new hole is made within the brain to bypass the obstruction in the brain. This procedure is called a Neuroendoscopic Third Ventriculostomy (NTV).
Only certain patients are suitable for a Ventriculostomy. These patients will be shunt free if the procedure is successful. The patients who are most suitable include those who are older than six months of age and have a blockage causing the hydrocephalus (usually aqueduct stenosis). Ventriculostomy may also be performed in certain patients who present with a shunt which has malfunctioned. Every patient presenting with hydrocephalus should be considered for a Third Ventriculostomy. Many will however be unsuitable. The overall success rate depends on the selection of the patients. The success rate is around 75%.
Complications of Third Ventriculostomy
The procedure may fail. Damage can occur to the blood vessels (basilar artery, usually fatal). Damage can also occur to the memory circuits, especially in inexperienced hands.