Ventriculoperitoneal (VP) Shunt Placement
Ventriculoperitoneal (VP) shunt placement is a procedure that is performed to treat hydrocephalus, which is a condition where cerebrospinal fluid (CSF) is abnormally accumulated, primarily within chambers in the brain (called ventricles), causing pressure on various structures within the brain. This can occur as a result of a variety of reasons, including brain tumors, bleeding inside of the brain, meningitis, and more. Such conditions lead to hydrocephalus through disruption of the delicate balance between production and absorption of CSF, which normally occurs in the healthy brain.
Since there are no medications that can reliably control the production or absorption of CSF over an extended period of time, the treatment of hydrocephalus is typically through diversion of the flow of the abnormally-accumulated CSF into another part of the body, where it can be absorbed back into the blood stream. While a variety of similar surgical methods exist to achieve this goal, the most common one is placement of a ventriculoperitoneal shunt. In this procedure one end of a long and thin plastic tube (catheter) is placed inside of the brain ventricle (where CSF has accumulated) and the other end is tunneled underneath the skin down to the peritoneal cavity (inside the abdomen), allowing the flow of fluid from the brain into this cavity, where it is then reabsorbed (as illustrated in the figure below).
A valve is also typically placed across this catheter in order to control the flow of CSF.
After induction of general anesthesia, a small incision is made either over the front part of the skull (just behind the hairline) or toward the back of the skull (above and behind the ear). The skin is retracted away, after which a drill is used to place a small hole in the skull. An opening in the dura mater (the covering of the brain) is then made and a thin, flexible catheter is passed through the opening into the ventricle (gray curved structures in the figure below).
This catheter is then attached to a valve (which controls the flow of the CSF) and the valve is connected to a thin and long plastic catheter (distal catheter) which is then tunneled under the skin from the scalp down toward into the abdominal cavity. Sometimes a small incision is made directly behind the ear in order to assist with the tunneling of the distal catheter.
A small incision is then made in the lower abdomen in order to aid in the placement of the tip of the distal catheter inside of the peritoneal cavity where CSF will be drained and absorbed. The incisions are then closed prior to the termination of the operation.
Due to advances in medicine and technology, surgical procedures are generally considered to be safe, and a great majority of patients who undergo surgery will not experience any complications. However, there are certain risks involved in any procedure which are important to be aware of in order to make an informed treatment decision.
Risks Specific to this Procedure: The risks associated with this surgery include, but are not limited to, damage to brain leading to increased neurologic problems, impaired memory and/or cognition, weakness or paralysis, numbness, seizures, loss of speech, coma, and need for further surgery or treatment.
Infection: Invasion of tissue, the catheters, or the valve by bacteria or other germs occurs to some degree whenever a cut, incision or puncture is made. In most instances, through the natural defense mechanisms of the body, healing of the affected area occurs without difficulty. In some instances antibiotic medicines are prescribed and at times additional surgical measures may be necessary to combat infection.
Hemorrhage: The cutting of blood vessels causes bleeding and this occurs in every surgical incision. This bleeding is usually controlled without difficulty. At times, blood transfusions are required to replace blood loss. If blood transfusions are given, there are additional risks of liver inflammation, hepatitis, and the possibility of receiving Acquired Immune Deficiency Syndrome (AIDS). There is no absolutely reliable way to predict these unwanted reactions, some of which may be quite serious and even lead to death.
Drug Reactions: Unexpected allergies, lack of proper response to medications or illness caused by the prescribed drugs are possibilities. It is important for you to inform your physician and your anesthesiologist or certified registered nurse anesthetist of any problem you or your family have had with reactions to drugs and which medications you have taken in the past six months, including over-the-counter drugs, especially aspirin.
Anesthesia Reactions: There may be unusual or unexpected responses to the gases, drugs or methods used to anesthetize you which can lead to difficulties with lung, heart or nerve function. Eating or drinking before anesthesia increases the risks of vomiting which may cause significant complications. Inform your anesthesiologist or certified registered nurse anesthetist of problems you and your family have had with anesthesia.
Blood Vessel Inflammation and Clotting: It is impossible to predict the occurrence of blood vessel inflammation and clotting problems. If blood clots form, they can move from where they formed to other areas of the body and cause injury.
Injury to Other Organs: Because of the closeness of other organs to the area being operated on, there may be injury to other organs. The stress of surgery or the procedure may also harm other organ systems of the body.
The alternative management modalities for this procedure depend on the reason for the hydrocephalus and vary from expectant management with no treatment at all to various types of surgical procedures aimed at removing the source of CSF flow obstruction or diversion of CSF flow. If the decision is made to not have this procedure, there may be associated risks which need to be discussed with a physician.