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Shunt Procedure

What does a shunt operation entail?

The surgical procedure to implant a shunt typically requires about an hour in the operating room. The patient generally stays under careful neurological observation for the first 24 hours following the procedure. Patients generally stay in the hospital from one to seven days. Follow-up visits will be necessary to check post-operative status and resolution of symptoms. After surgery, physical therapy, occupational therapy and other rehabilitation strategies may be advised to help patients attain as much resolution of symptoms as possible.

How successful is shunting in treatment of hydrocephalus?

The symptoms of gait disturbance, mild dementia and bladder control problems may improve within days of shunt surgery, or may take weeks to months to subside. Other factors that affect the outcome after shunt surgery are the presence of other neurological or medical conditions. The more symptoms are due to NPH, rather than the associated conditions, the greater the likelihood of successful recovery after shunting. In about 10% of patients, for reasons that are not well understood, patients do not demonstrate a long term response to shunting despite initial improvement. Some patients may develop additional disorders of the brain that also affect gait and memory that will not respond to CSF drainage from the shunt.

What are the complications and risks involved with shunting?

The potential complications of shunt surgery include those related to the actual operation, as well as those that may occur days to years later. One of the most common problems with shunt systems is that they can become obstructed; however it can usually be easily fixed and rarely results in serious problems. In that case, further surgery may be necessary. Other common complications include: shunt malfunction; infection at the site of the surgical wound; the shunt or the CSF (meningitis); bleeding into the brain or ventricles; or a seizure. Some complications can lead to other problems such as over drainage or under drainage. Over drainage occurs when the shunt allows CSF to drain from the ventricles more quickly than it is produced. Over drainage can cause the ventricles to collapse, tearing blood vessels and causing headache, hemorrhage (subdural hematoma), or slit-like ventricles (slit ventricle syndrome). This risk occurs approximately 5 to 10 percent of the time. Under drainage occurs when CSF is not removed quickly enough and the symptoms of hydrocephalus recur.  Given the potential complications, individuals and their families need to assess their own situation to determine if the possible benefits of surgery outweigh the possible risks. In addition to the common symptoms of hydrocephalus, infections from a shunt may also produce symptoms such as a low-grade fever, soreness of the neck or shoulder muscles, and redness or tenderness along the shunt tract. When there is reason to suspect that a shunt system is not functioning properly (for example, if the symptoms of hydrocephalus return), medical attention should be sought immediately.

What kinds of shunts are available for treatment of NPH?

Shunts can be programmable (externally adjustable by a magnetic device) or non-programmable. While no trials have proven the superiority of programmable vs. non-programmable shunts in clinical studies, in general practice, programmable shunts are implanted. There are various manufacturers of programmable shunts and no specific make of shunt has been proven to be more effective than others.

What are the different ways to implant shunts?

Shunts can be implanted in the ventriculo-peritoneal (brain to abdominal cavity), ventriculo-atrial (brain to heart), ventriculo-pleural (brain to lung) or lumbo-peritoneal (spinal column to abdominal cavity) configuration depending on several factors. The neurosurgeon will discuss the pros and cons of each approach with you.

What is an anti-siphon device?

An anti-siphon device slows down the flow of CSF in the upright position while still permitting the valve to regulate flow when the person is lying down. To prevent complications related to over-drainage from the shunt (see above) your surgeon may elect to implant an anti-siphon device along with your shunt. Depending on your individual case different strengths of an anti-siphon device may be implanted.

What do the different shunt settings mean?

In general, a higher shunt setting means less fluid is being drained.  A lower setting means more fluid is being drained. The settings vary for each manufacturer. The number does not correspond to intracranial pressures.

What precautions do I need to take if I have a programmable shunt?

Your shunt valve setting can be changed by your physician using a programming device, or it can be changed accidentally if you come close to a magnet, even ones found in headphones. Have your shunt setting confirmed by contacting us if:

  1. You experience headache, persistent nausea, vomiting, drowsiness, weakness, seizures, slurred speech or worsening gait and balance
  2. You have an MRI for any reason (CT scans have no effect on the shunt)
  3. Before you schedule an MRI to arrange for the valve to be adjusted the same day

Some newer types of shunts are not affected by MRI’s or magnetic fields.

Always confirm with your physicians if the kind of shunt you have is affected by magnetic fields.

What specific precautions do I need to take if I have a VP (Ventriculo-peritoneal) shunt?

Notify us before any abdominal surgery, so proper precautions can be discussed with your surgeon. Notify us if you have appendicitis, peritonitis or diverticulitis requiring emergency surgery or antibiotic treatment.

What specific precautions do I need to take if I have a VA (Ventriculo-atrial) shunt?

Antibiotics should be taken 30-60 minutes before any surgical or dental procedure is performed. Aspirin should be taken every day to prevent blood clots at the distal end of the catheter.

What are the symptoms of shunt infection?

Signs suggestive of infection include fever, chills, neck stiffness and tenderness or redness along the shunt site. Should you experience any of these symptoms, call 911 immediately and go to the nearest emergency room.

How long do shunts last?

It is difficult to predict how long shunts will last before the need for revision. In our experience about 50% of shunts need to be revised over 6 years.


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