The most common treatment for hydrocephalus is a shunt - a thin plastic tube inserted entirely under the skin that creates a new path for the CSF, from the brain to another part of the body. Shunts are not perfect, they may malfunction, clog, or break. One problem with shunts has been infection. Shunts are made of foreign material, and thus are more prone to infection than normal body tissue. Many studies suggest that shunt infections are due to microscopic contamination at the time of implantation. Shunt infection rates in the 1990's were often reported to be in the 5-9% range, far higher than for other implanted foreign bodies, such as pacemakers or joint replacements.

Considerations

Size of patient: Ventriculoperitoneal shunts are most often inserted (and revised) in children. The size of the patient is important because of the size of the instruments that must be used, the size of the devices that are implanted, and because of the limited blood volume of the smallest patients (premature infants) who undergo these procedures.

Length of procedure: In patients who have never had a VP shunt inserted before, a shunt can usually be inserted in less than an hour. It is important to try to do the procedure as quickly as possible to minimize the risk of infection (the most common complication of VP shunt insertion). The procedure can be done in an hour or less.

Two body cavities must be entered during the procedure: the ventricle and the peritoneum. Some surgical teams find it more efficient to have one surgeon open the head and catheterize the ventricle at the same time that a second surgeon opens the abdomen into the peritoneal space.

Foreign bodies: The ventricular catheter, valve, and peritoneal tubing are all foreign bodies that can harbor bacteria introduced by contamination at the time of surgery or subsequently by seeding of organisms introduced into the blood stream by a variety of surgical and non-surgical mechanisms unrelated to the VP shunt insertion procedure.

Insertion of a ventriculoperitoneal shunt takes approximately 1 1/2 hours.

What happens afterwards?

After VP shunt insertion the patient is usually taken to Recovery. Immediately post-operatively the patient is monitored for signs of neurologic deficit for a duration of approximately an hour. Once recovered, in the absence of any apparent complication, they are taken to a regular hospital ward.

A follow up CT (or MR) is sometimes obtained to verify that the ventricular catheter tip is located at the desired location in the anterior horn of the lateral ventricle close to the foramen of Monro.

Recovery

Most patients are discharged the morning after an uncomplicated VP shunt insertion.

The abdominal and scalp incisions usually heal within 7 days after which time the patient can get them wet. Patients can usually return to work within two weeks of VP shunt insertion.

Rehabilitation

Rehabilitation may be required for patients with serious long term disability resulting from their hydrocephalus -- the disability in most of these patients will neither worsen nor improve with shunting.

Follow up

Most patients with uncomplicated VP shunt insertion are sent home the day after surgery with a prescription for pain medication and possibly for an oral antibiotic to be taken for 7 to 10 days.

After discharge from the post surgical unit the patient following VP shunt insertion should be seen in the Outpatient/Ambulatory Clinic 7 to 10 days post-operatively for suture or staple removal and wound check.

Reoperation

Revision (re-operation for removal or adjustment or one or all components of) a ventriculoperitoneal shunt system is one of the most common procedures done by neurosurgeons (particularly those who operate on large numbers of children).

Risks & complications

• Tunneling device tip through skin

• Pneumothorax

• Intestinal injury

• Parenchymal placement

• Hemorrhage

• Infection

• Obstruction

• Disconnection

• Subdural hematoma

Prognosis

The prognosis depends on the condition for which the patient was shunted and their neurologic status at the time of operation.