Chiari Decompression Surgery & Treatment Options for Related Conditions

The first step in the diagnostic process is a thorough neurological evaluation with our nurse practitioner. The evaluation assesses cognitive and cerebellar function, reflexes, sensory and motor skill and cranial nerve function.

If not already complete, labs and imaging studies will be performed to create an anatomical picture of the brain and cervical spine. These imaging studies may include MRI or CINE MRI flow analysis.

If Chiari 1 Malformation is confirmed, your neurosurgeon will discuss the various treatment options available. If necessary, Chiari decompression surgery and reconstruction can be performed to reshape the opening at the base of the skull, thereby relieving pressure on the protruding brain tissue. Our research shows 84 percent of patients experience significant improvement in their symptoms one year after surgery.

Not everyone with Chiari will need to have surgery. Conservative treatments will be considered including medications to help manage the symptoms, dietary recommendations, and lifestyle changes.

Patient may be referred to CCI by a neurologist, primary care provider or neurosurgeon, if there is evidence of Chiari on the MRI report.

Please note that Colorado Chiari Institute does not treat children younger than 16 years of age. For patients under the age of 16, please refer to these sites:

ASAP Medical Advisory Board

CSF Scientific Educational & Advisory Board

Surgery and Treatment Options for Chiari Malformation and Related Conditions

Colorado Chiari Malformation Surgery - What to Expect

The surgical treatment of the Chiari 1 malformation is called a posterior fossa decompression. The surgery is customized for each patient based on an analysis of the morphology (shape and form) of the skull, the effect on neurological tissues and the findings during surgery.

During surgery, the patient is asleep under general anesthesia. An area of hair about two inches wide is shaved at the back of the head. An incision is created from the occipital area at the back of the head to upper neck. The tissues are separated to expose the back of the skull and the cervical one (C1) Vertebrae. Bone is removed at the base of the back of the skull and from the back part of the C1 vertebrae. In rare cases, the lamina (roof bone) of C2 is also removed.

Once the bone in this area is removed, a tough membrane, called the dura matter, is seen. Ultrasound is performed to show the tonsils, the degree of crowding, and most importantly, the location of the blood vessels in the area. This helps guide the opening of the dura membrane.

Once the dura membrane is opened, the position of the tonsils and the degree of crowding is assessed. In patients with a syrinx, it is important to look between the tonsils and make sure that a drainage path for spinal fluid, the foramen of Magendie, is open. Sometimes a thin veil is found over the foramen that must be opened to free spinal fluid flow.

In some cases, marked crowding is present despite opening of the dura. In these cases, the tips of the cerebellar tonsils are reduced in size with electrocautery, which is applied with a fine pincer forceps. No specific side effects have been described from this shrinkage. The important point is to create more room in the area, remove the crowding, and allow for normal spinal fluid flow.

Next, a patch of tissue is sewn to the edges of the open dura to enlarge the dural sac. The patch material, called pericranium, is tissue obtained from underneath the scalp in the area just above the bony removal.

Once the patch is sewn in, a customized titanium plate is attached to the edges of the bony resection by very small titanium screws. The plate covers but does not compress the area of decompression. The muscles that were previously attached to the bone in this area can now adhere to the plate. This union allows for natural reconstruction and helps avoid the sunken defect that some people develop after posterior fossa decompression surgery.

Lastly, the tissues are closed with stitches. Staples are used to close the skin.

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Syringomyelia Surgery & Treatment

The best treatment for syringomyelia is to remove the block to normal spinal fluid flow if there is one. In patients with syringomyelia, due to the blockage caused by a Chiari 1 malformation, the goal is to create more room at the foramen magnum (through a posterior fossa decompression). For many, the improved spinal fluid flow will result in the syrinx slowly decreasing in size, although it may not disappear completely. The goal is to keep the syrinx from growing and allow it to relax and decrease in size.

When syringomyelia is due to spinal injury, release of the scar bands around the spinal cord can result in a decrease in the size of the syrinx. When it is due to a spinal cord tumor, usually the best treatment is removal of the tumor, if possible. When the cause of the syrinx is not known, the treatment decisions are more difficult. Some people may respond to sectioning the band at the end of the spinal cord, the filum terminale if it is tethered. If the syrinx is small and the symptoms are under control, observation and follow-up MRI scans may be the best option.

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Recovery After Surgery, Surgery Risks & Surgery Outcomes Research Study

Recovery After Chiari Decompression Surgery

Healing after surgery is a gradual process

You will experience some good days and some days when things seem achy or sore. This is normal. Slowly increasing activity, eating healthy, avoiding strenuous lifting, adhering to your doctor's advice/instructions and maintaining a positive attitude are the best ways to allow your body to recover. Concentrate and focus on the symptoms that have improved, instead of what symptoms remain. The goal is not to recover fully in the first two weeks but to generally progress and recover over the months following surgery.


After discharge from the hospital, you may be up and walking around the house the first week. This is a time of healing, so it is important to remember to not overdo the activity. The body needs time to rest; therefore, some patients take a nap in the afternoon. Activities such as washing dishes, fixing light meals and dusting are fine. Avoid activities such as vacuuming, lifting, carrying or anything that requires stretching of the neck muscles. Do not lift anything heavier than a gallon of milk (about 10 pounds) during the first month after surgery. If you are recovering well during the second month, you can increase your lifting by five pounds per week until you reach what is comfortable for you.


Do your best to keep the incision clean and dry at all times. You may shower about 48 hours after surgery, but you should try to keep the incision dry and be sure not rub or soak the incision.

It is best to use very light shampoos such as baby shampoo for the first three weeks after surgery. In addition, be sure not to use any dye, hair color or other hair treatments like perm solutions until your follow up appointment.


You should avoid driving for the first few weeks after surgery - and especially if you are using pain medications. Movement of the neck may feel tight, and it is difficult to see in all directions when driving. DO NOT DRIVE if taking narcotic pain medications.


Good nutrition is an essential part of healing and recovery. Eat a balanced diet each day, including fruits and vegetables, and protein, to help aid in the healing process. A multivitamin is not necessary, unless one is taken normally. Remember to drink plenty of water.


The neck incision may be tender and stiff for several days. This is normal. Avoid rubbing or scrubbing the area until the staples are removed. If any redness, swelling, heat, or drainage is noticed around the incision, the neurosurgeon needs to know immediately.

Most people resume their normal medications after surgery. You will also receive a prescription for pain medication after discharge. The pain medication works best if taken every 6-8 hours before the pain worsens. To reduce upset stomach, take the medication with food. Pain medication should not be necessary after the second week. If a refill is needed on pain medication, do not wait until the bottle is empty - call our office at least two days before the prescription runs out. DO NOT DRIVE if you are taking narcotic pain medications.

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Chiari 1 Malformation Surgery Risks

When you consider surgical treatment, it is helpful to weigh your current condition against the possible benefits and risks of surgery. It is important to ask questions until you are comfortable with your understanding of the procedure, the possible benefits and the associated risks.

The risks of surgery include: leakage of spinal fluid through the membrane repair that creates a fluid pocket in the muscle (pseudomeningocele), infection in the wound or in the spinal fluid (meningitis), occipital pain (occipital neuralgia) and neurological injury such as hemorrhage or stroke. As with any major surgery under general anesthesia, pneumonia and cardiac problems are also possible.

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Chiari Surgery Outcomes Study

Colorado Chiari Institute founder, Dr. Jon Oro and colleague, Diane Mueller, published the first Chiari outcome study using a quality of life measure: the Sickness Impact Profile. Their findings show that 84 percent of people reported significant improvement in their symptoms one year after surgery. Some people have remarkable recoveries; others show improvement but still have problems that linger. Recovery takes time and you should set realistic expectations for yourself.

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