Chiari malformation refers to a condition in which the brain doesn't fit into the back part of the skull and so gets squeezed down into the top part of the spinal canal. Some people don't have symptoms, but others experience headaches and other problems. For serious symptoms, neurosurgeons may recommend decompression, in which pieces of the skull are removed to relieve the pressure on the brain. Decompression surgery is generally effective in symptom relief, but it does have some potential complications.
Infection
Postoperative infection is a common complication for any surgery. According to the Centers for Disease Control and Prevention, surgical site infections, or SSIs, occur in about 1 percent of cases. Signs of an SSI include redness, warmth and inflammation around the incision, and a fever. SSIs can usually be treated with antibiotics. A deeper infection after Chiari decompression surgery, though rare, could lead to bacterial meningitis, a serious condition that requires immediate medical attention. Even more unusual is an infection in the bone called osteomyelitis, a painful condition that is treated with antibiotics.
Cerebrospinal Fluid Leakage
The brain and spinal cord are surrounded by a membrane called the dura, and within the dura is a substance called cerebrospinal fluid, or CSF. According to the "British Journal of Neurosurgery," some surgeons open the dura and place a patch as part of the decompression surgery, while others don't due to the increased risk of infection and studies indicating it may not improve the outcome, especially in children. If a tear in the dura isn't repaired, the CSF may leak from the opening. Signs of a CSF leak include a headache that worsens when the patient is upright and improves with lying down, or a runny nose. Many tears heal spontaneously, but doctors usually recommend bed rest.
Scarring
Decompression surgeries often have to be repeated. Sometimes the repeat surgery is to further expand the opening because the brain is still growing, or the original surgery just didn't go far enough. Sometimes further surgery is needed because of postoperative scarring or adhesions. Scars or adhesions are fairly common following surgeries, and they're only a problem in Chiari malformation decompressions if the scarring ends up restricting the space that was created to relieve pressure on the brain.
Other Rare Complications
Hemorrhage, slumping of the brain further into the spinal canal, called cerebrospinal sag, and hydrocephalus are other possible, though rare, complications associated with Chiari decompression surgery, according to the Pediatric Neurosciences Institute at Hackensack University Medical Center. All of these are treatable.
References
- C&S Patient Education Foundation: In the Spotlight: Dr. Ghassan Bejjani, Neurosurgeon & Chiari Researcher
- Centers for Disease Control and Prevention: Surgical Site Infection (SSI) FAQ
- "British Journal of Neurosurgery": Hindbrain decompression for Chiari-syringomyelia complex: an outcome analysis comparing surgical techniques
- Columbia University Department of Neurological Surgery: Chiari Malformation
- Neurosurg Focus 15: Revision surgery for chiari malformation decompression
