Shunts in Treatment of Hydrocephalus
The use of shunts in treatment of hydrocephalus is the most common method chosen. The hydrocephalus shunts are made from a special kind of rubber, and when combined with a catheter and a valve, they divert cerebrospinal fluid to another part of the body. Complications related to shunts include mechanical failure, infection, and overdraining.
Hydrocephalus is most often treated with the surgical placement of a shunt system. Shunts divert the flow of cerebrospinal fluid (CSF) from a site within the central nervous system (CNS) to another area of the body, where it can be absorbed as part of the circulatory process.
A hydrocephalus shunt is a flexible but sturdy Silastic® (a type of silicone rubber) tube. A hydrocephalus shunt system consists of the shunt, a catheter, and a valve. One end of the catheter is placed in the CNS -- usually within a ventricle inside the brain, but also sometimes within a cyst or in a site close to the spinal cord. The other end of the catheter is often placed within the abdomen, but may also be placed at other sites within the body, such as a chamber of the heart or a cavity in the lung, where the CSF can drain and be absorbed. A valve located along the catheter maintains one-way flow and regulates the CSF flow rate.
Hydrocephalus shunts are not perfect devices. Possible complications of shunts in treatment of hydrocephalus may include, but are not limited to:
- Mechanical failure
- The need to lengthen or replace the catheter.
Generally, hydrocephalus shunt systems require monitoring and regular medical follow-up. When complications do occur, usually the shunt system will require some type of revision.
Some complications can lead to other problems, such as overdraining or underdraining. Overdraining occurs when the shunt allows CSF to drain from the ventricles more quickly than it is produced. This overdraining can cause the ventricles to collapse, tearing blood vessels and causing headache, hemorrhage (subdural hematoma), or slit-like ventricles (slit ventricle syndrome). Underdraining occurs when CSF is not removed quickly enough and the symptoms of hydrocephalus recur.
In addition to the common hydrocephalus symptoms, 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.