A ventriculoperitoneal (VP) shunt is a medical device designed to manage excess cerebrospinal fluid (CSF) within the brain. This implanted system diverts surplus fluid from the brain to the abdominal cavity. Its primary purpose is to alleviate harmful pressure that builds up inside the skull when CSF does not drain properly. The VP shunt helps maintain a balanced fluid environment within the brain.
Conditions Requiring a VP Shunt
The main condition necessitating a VP shunt is hydrocephalus, an excessive buildup of cerebrospinal fluid within the brain’s ventricles. This accumulation can lead to increased pressure on brain tissues, potentially causing damage.
Hydrocephalus can be congenital, often linked to genetic factors or developmental abnormalities like spina bifida. Acquired hydrocephalus can develop later in life due to head injuries, brain tumors, or infections like meningitis. In older adults, Normal Pressure Hydrocephalus (NPH) may also occur, where CSF accumulates without significantly elevated pressure.
How a VP Shunt Functions
A VP shunt system consists of three main components that regulate cerebrospinal fluid flow. The ventricular catheter, a thin, flexible tube, is placed within one of the brain’s ventricles. This catheter has small holes to collect CSF.
A valve connects to the ventricular catheter, typically positioned under the skin on the scalp, often behind the ear. This valve controls the rate at which CSF drains, preventing over-drainage or under-drainage. Some valves are programmable, allowing medical professionals to externally adjust the drainage rate to suit the patient’s individual needs.
The third component is a long, thin distal catheter, which extends from the valve. This catheter is tunneled under the skin, usually down the neck and chest, and its end is placed into the peritoneal cavity within the abdomen. The body naturally absorbs the fluid into the bloodstream there.
The Surgical Placement
Implanting a VP shunt is a neurosurgical procedure performed under general anesthesia. The entire process usually takes about 90 minutes. Before surgery, a small area of hair on the scalp may be shaved, and the area is thoroughly cleaned.
During the procedure, a small incision is made in the scalp, and a hole drilled into the skull to access the brain’s ventricles. The ventricular catheter is inserted into a ventricle, sometimes guided by imaging technology. Another incision is made in the abdomen to position the distal catheter in the peritoneal cavity. The valve connects both catheters, and incisions are closed with stitches or staples. Most patients stay in the hospital for two to five days, with full recovery taking several weeks.
Living with a VP Shunt
Individuals with a VP shunt can lead full and active lives, though adjustments and ongoing awareness are important. Routine follow-up appointments with medical professionals monitor the shunt’s function. These visits may involve checking the shunt’s pressure settings, especially if a programmable valve is in place.
Patients should report any changes to their medical team. The shunt is entirely inside the body. Most daily activities, including sports, can be resumed, but activities involving severe blows to the head should be avoided. Regular communication with healthcare providers helps ensure proper management and timely intervention if issues arise.
Common Complications
VP shunts can experience complications, primarily malfunction or infection. Shunt malfunction occurs when the system stops working, often due to blockage, disconnection, or breakage of its components. Blockages are caused by tissue or debris obstructing the catheters.
Signs of shunt malfunction often resemble the original symptoms of hydrocephalus, as pressure inside the brain increases again. These can include headaches, nausea, vomiting, excessive sleepiness, and changes in behavior or mental status. In infants, symptoms might also include an enlarged head or a tense soft spot (fontanelle). If any of these signs appear, seek prompt medical attention.
Infection is another common complication, typically occurring within the first few months after surgery. Bacteria can enter the shunt system. Symptoms of an infected shunt may include fever, redness or swelling along the shunt’s path, headache, neck stiffness, or abdominal pain. Early recognition and treatment of complications avoid serious health consequences.