Chiari decompression surgery
Chiari decompression surgery removes bone at the back of the skull to widen the foramen magnum and create space for the brain. The dura overlying the herniated tonsils is opened and a patch is sewn to expand the space, similar to letting out the waistband on a pair of pants. The goals of surgery are to control the progression of symptoms, relieve compression, and restore the normal flow of cerebrospinal fluid (CSF). The surgery takes about 2 to 3 hours and recovery in the hospital usually lasts 2 to 4 days.
What is Chiari decompression?
Posterior fossa decompression is a surgical procedure that removes bone at the back of the skull and spine to widen the space for the tonsils and brainstem (Fig. 1 and 2).
Many patients ask about minimally invasive or endoscopic surgery. Minimally invasive can mean different things: shorter skin and muscle incision, no dura opening, no shrinkage of the tonsils, or use of ultrasound and endoscopes. Despite what the words "minimally invasive" suggest, the amount of bone removal needed to effectively restore normal CSF flow depends on the individual patient's anatomy and size of Chiari. The amount of bone removal should be the same in any procedure, endoscopic or standard "open" technique. It's also important to understand that some minimally invasive techniques used for children (whose skulls are still growing) may or may not be appropriate for adults.
Spinal fusion may be performed in addition to posterior fossa decompression surgery in certain patients with spine instability due to scoliosis, Ehler-Danlos syndrome, or other bone abnormality. Rods and screws are inserted to structurally reinforce the skull and neck vertebrae.
Who is a candidate?
You may be a candidate for surgery if you have:
- An abnormal collection of CSF in the spinal cord called a syrinx.
- A Chiari malformation obstructing CSF flow (confirmed by cine MRI) and is causing severe or worsening symptoms.
What happens before surgery?
During the office visit, the neurosurgeon will explain the procedure, its risks and benefits, and answer any questions. Next, you will sign consent forms and complete paperwork to inform the surgeon about your medical history (i.e., allergies, medicines, vitamins, bleeding history, anesthesia reactions, prior surgeries). Discuss all medications (prescription, over-the-counter, and herbal supplements) that you are taking with your healthcare provider. Some medications will need to be continued or stopped the day of surgery. You will be scheduled for presurgical tests (e.g., a blood test, electrocardiogram, chest X-ray, and CT scan) several days before surgery.
Stop taking all non-steroidal anti-inflammatory medicines (Naprosyn, Advil, Motrin, Nuprin, Aleve) and blood thinners (coumadin, Plavix, aspirin) 1 week before surgery. Stop smoking and chewing tobacco 1 week before and 2 weeks after surgery because these activities can cause bleeding problems. Wash your hair with Hibiclens® (chlorhexidine) antiseptic soap for 3 consecutive days before surgery. No food or drink is permitted past midnight the night before surgery.
Morning of surgery
- Shower using antibacterial soap. Dress in freshly washed, loose-fitting clothing.
- Wear flat-heeled shoes with closed backs.
- If you have instructions to take regular medication the morning of surgery, do so with small sips of water.
- Remove make-up, hairpins, contacts, body piercings, nail polish, etc.
- Leave all valuables and jewelry at home (including wedding bands).
- Bring a list of medications with dosages and the times of day usually taken.
- Bring a list of allergies to medication or foods.
- Bring your CPAP machine to the hospital if you have one.
Arrive at the hospital 2 hours before your scheduled surgery time to complete the necessary paperwork and work-ups. The nurse will explain the preoperative process and discuss any questions you may have. An anesthesiologist will talk with you to explain the effects of anesthesia and its risks. An intravenous (IV) line will be placed in your arm before transport to the operating room.
What happens during surgery?
Step 1: prepare the patient
You will lie on the operating table and be given anesthesia. Once you are asleep, your head will be placed in a 3-pin skull-fixation device that attaches to the table and holds your head in position during surgery. An inch wide strip of hair is shaved along the planned incision. The scalp is prepped with an antiseptic.
Step 2: make a skin incision
A skin incision is made down the middle through the neck muscles so that the surgeon can see the skull and top of the spine. The skin incision is about 3 inches long (Fig. 3). The skin and muscles are lifted off the bone and folded back.
Step 3: remove bone
The surgeon removes a small section of skull at the back of your head (suboccipital craniectomy). In some cases the bony arch of the C1 vertebra may be removed (laminectomy). These steps expose the protective covering of the brain and spinal cord called the dura (Fig. 4). Bone removal relieves compression of the tonsils.
Step 4: open the dura
Next, the surgeon opens the dura to view the tonsils and cisterna magna (Fig. 5). Some surgeons perform a Doppler ultrasound study during surgery to determine if opening the dura is necessary. Sometimes bone removal alone may restore normal CSF flow.
Step 5: reduce the tonsils (optional)
Depending on the size of herniation, the stretched and damaged tonsils may be shrunk with electrocautery. This shrinkage ensures that there is no blockage of CSF flow out of the 4th ventricle.
Step 6: attach dura patch
A patch of synthetic material or the patient’s own pericranium (a piece of deep scalp tissue just outside the skull) is sutured into place (Fig. 6). This patch enlarges the dura and the space around the tonsils. The dural patch is sutured in a watertight fashion. The suture line is covered with a dural sealant to prevent CSF leak (Fig. 7).
Step 7: close the incision
The strong neck muscles and skin are sutured together. A dressing is placed over the incision.
What happens after surgery?
You will wake up in the recovery area. Your throat may feel sore from the tube inserted to assist your breathing during surgery. Once awake, you’ll be moved to your room. Your blood pressure, heart rate, and breathing will be monitored. If you feel nausea or headache after surgery, medication can be given. When your condition stabilizes, you will be discharged in the care of family or a caregiver, usually 1 or 2 days after surgery. Discharge instructions for home:
- After surgery, pain is managed with narcotic medication. Narcotics can be addictive and are used for a limited period of time. Thereafter, pain is managed with acetaminophen (e.g., Tylenol) and nonsteroidal anti-inflammatory drugs (NSAIDs) (e.g., aspirin; ibuprofen, Advil, Motrin, Nuprin; naproxen sodium, Aleve.
- Narcotics can also cause constipation. Drink lots of water and eat high-fiber foods. Stool softeners and laxatives such as Dulcolax, Senokot, Colace, and Milk of Magnesia are available without a prescription.
- Ice packs for 20 minutes 3 times a day can help relieve neck and shoulder pain and muscle spasms. Muscle relaxants may be prescribed.
- Avoid activities that increase pressure in the head:
- Bending over, with head low
- Straining, bearing down when having a bowel movement; avoid constipation
- Prolonged coughing; hold your face to sneeze
- Nodding in the “yes” position
- Do not drive until after your follow-up appointment.
- Do not lift anything heavier than 5 pounds for 2 weeks after surgery.
- No strenuous activity for the next 2 weeks including yard work, housework and sex.
- Do not drink alcohol for 2 weeks after surgery or while you are taking narcotic medication.
- Begin balance exercises and neck stretches as instructed.
- Get up and walk 5-10 minutes every 3-4 hours. Gradually increase your walking time, as you are able. Avoid getting over heated.
- Shower and wash hair with mild shampoo after surgery unless otherwise directed.
- Do not submerge or soak the incision in water (bath, pool or tub).
- Sutures, steri-strips or staples, if used, will be removed at your follow-up appointment.
When to Call Your Doctor
- Fluid may accumulate under the skin around the incision. A visible swelling that is soft and squishy may be a sign of cerebrospinal fluid (CSF) leakage. A clear sticky fluid may leak from the incision. Call the surgeon should any drainage occur.
- If you experience any of the following:
- A temperature that exceeds 101º F
- An incision that shows signs of infection, such as redness, swelling, pain, or drainage.
- Decreased alertness, increased drowsiness, weakness of arms or legs, increased headaches, vomiting, or severe neck pain that prevents lowering your chin toward the chest.
Before you leave the hospital, appointments with the neurosurgeon will be scheduled 10 to 14 days after surgery to remove your sutures and check your recovery. Recovery from the actual surgery varies from 4 to 6 weeks, depending on your general health.
After surgery, you can expect headache and neck pain from the incision that may last several weeks. You will be given neck exercises (download exercises) to do at home. These will help with neck mobility and healing.
Patients typically return to work in 4 to 6 weeks, but be sure to check with your surgeon. A follow-up cine MRI is planned for 6 months to 1 year.
Recovery from the Chiari syndrome and its symptoms may take months or longer. Returning to "normal" is gradual – time is your best ally. Slowly increase activity, avoid strenuous lifting, adhere to instructions and maintain a positive attitude. Focus on the symptoms that have improved, and have patience with those symptoms that remain. Keep a symptom diary to track your progress over time.
What are the results?
The results of your decompression surgery depend on the severity of the Chiari malformation and the extent of any previous brain and nerve injury before treatment. Eighty five to 95% of patients experience major relief of symptoms . However, patients may continue to have residual symptoms from syringomyelia. If injury in the spinal cord has already become permanent, surgery won't reverse the damage.
Exertional headache and neck pain respond well to decompressive surgery as do most of the brainstem signs (e.g., swallowing problems, facial pain/numbness, voice changes, tinnitus, eye problems, dizziness). Recovery of sleep problems, memory, and spinal cord signs (e.g., numbness or tingling in hands and feet, muscle weakness) take longer and may not completely return to normal.
Decompression surgery may allow the syrinx to drain on its own. Follow up is needed to monitor CSF flow and the syrinx site. This progress is evaluated at 1 year with cine MRI (Fig. 8). For any residual symptoms, you and your doctor will discuss possible options to determine the best care.
Recurrence of compression or obstruction of CSF flow is rare.
What are the risks?
No surgery is without risks. General complications of any surgery include bleeding, infection, blood clots, stroke, reactions to anesthesia, and death (rare). Specific complications related to a Chiari decompression craniectomy and duraplasty may include:
- Risk of head and neck pain is variable.
- Cerebrospinal fluid (CSF) leakage is the escape of CSF that flows around the brain. This usually takes the form of a squishy pocket of fluid or drainage from the incision. If leakage is suspected, apply a pressure dressing over the incision and contact your surgeon immediately. If the leak continues, surgical repair may be necessary. New closure techniques and use of biologic glue reduces the risk of CSF leak.
- There is a risk of pseudomeningocele, an abnormal collection of cerebrospinal fluid (CSF) under the tissues of the neck. The collection may resolve on it’s own; however notify your surgeon if this occurs.
- Nerve or brain damage may cause permanent disability.
Q&A: chiari surgery
Q: Why do some surgeons remove bone from the vertebra in the neck?
A: The amount of tonsillar herniation is a determining factor to remove the arch of the C1 vertebra (e.g., someone with 4mm herniation versus someone with 20mm herniation). If a person is young or athletic, we always try to avoid disturbing the C1 vertebra. There have been cases where a person can develop craniospinal instability years after surgery, either by a neck injury or the natural aging process. Some surgeons prefer to shrink the tonsils rather than remove the bone of C1.
Q: Will more of my brain sag out of my head if you remove bone from the skull?
A: No. The bone removal is in the very middle of the skull to allow the tonsils more space. The cerebellar hemispheres are supported by bone along the undersides of the skull. Cases of cerebellar slumping (cerebellar ptosis) that you may have heard about are rare complications caused by too much bone removal.
Q: Does my syrinx need to be drained with a shunt?
A: No. Years ago placing a shunt into the syrinx cavity was common, but long-term results and problems with shunt clogging have made this technique uncommon and used only for special cases. Adequate decompression of the brainstem and fourth ventricle will allow CSF flow and pressure to normalize and should eventually lead to disappearance of the syrinx on its own.
Q: Why do some surgeons open the dura and some do not?
A: Sometimes bone removal alone is enough to relieve the compression and restore CSF flow (especially in children). Surgeons may use ultrasound to test the movement of CSF and determine if opening the dura and sewing a patch (duraplasty) is necessary. However, in adults the dura is less pliable, so a graft is sewn to enlarge the space. The technique is similar to a tailor letting out the waistband on a pair of pants. While avoiding dura opening may decrease the risk of CSF leak, inadequate decompression may increase the risk of a poor result and lead to reoperation.
Q: Is there a difference in dura patch material?
A: Many patch materials are available, ranging from autologous (patient’s own) tissue to a variety of cadaveric and synthetic materials. We prefer to use patch material obtained from the pericranium (tissue overlying the skull) or a synthetic collagen material.
Q: Does Chiari recur after surgery?
A: True anatomical recurrence of Chiari I is rare. There are many reasons why some patients consider their surgery unsuccessful or “failed.” Technical failure of the surgery means obstructed CSF flow at the foramen magnum. Failure of some symptoms to resolve does not always mean failure of the surgical repair. A cine MRI study is used to evaluate CSF flow.
Scarring of tissue, inadequate removal of bone, new neck or head trauma, increased brain pressure, and tethered cord can be causes of recurrence. Surgical complications such as cerebellar slumping or spinal instability can also cause recurrence.
Q: Why do some people have multiple surgeries?
A: Some patients have had an inadequate decompression to restore normal CSF flow. Either the bone removal was too small or the dura was not opened to adequately expand the space. Delayed post-operative scarring may also lead to repeat surgery. Cine flow and MRI studies play a major role in determining the need for reoperation.
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If you have questions, please contact Southeastern Neurosurgical Specialists
Endoscopic Transsphenoidal Surgery
Endoscopic Transsphenoidal Surgery: surgery to remove certain tumors via nasal passage, instead of opening the skull.
What is endoscopic transsphenoidal surgery?
Endoscopic transsphenoidal surgery is a procedure used to remove tumors from the pituitary gland, sphenoid sinus and sellar region through the nose and sphenoid sinus. The literal meaning of the term “endoscopic transsphenoidal” surgery is surgery “through the sphenoid sinus”.
Generally, only an endoscope is used for this surgery. However, a microscope can also be used with or without an endoscope. In this procedure, the surgeon reaches the pituitary tumor through the nose. This is a minimally invasive technique used for removing small tumors and anomalies.
Who needs endoscopic transsphenoidal surgery?
- PITUITARY ADENOMA: A TYPE OF TUMOR IN THE PITUITARY GLAND
- RATHKE’S CLEFT CYST: A SAC FILLED WITH FLUID, OR A CYST, LOCATED BETWEEN THE LOBES OF THE PITUITARY GLAND
- MENINGIOMA: A TUMOR GROWING OF THE DURA (I.E., THE PROTECTIVE COVERING OF THE BRAIN AND SPINAL CORD)
- CRANIOPHARYNGIOMA: A NON-MALIGNANT TUMOR GROWING NEAR THE PITUITARY STALK
- CHORDOMA: A MALIGNANT BONE TUMOR THAT AFFECTS THE BASE OF THE CRANIUM
How is endoscopic transsphenoidal surgery performed?
- IN THE OPERATING ROOM THE PATIENT WILL BE GIVEN GENERAL ANESTHESIA. A SYSTEM OF IMAGE-GUIDANCE IS PLACED ON THE HEAD TO ASSIST THE SURGEON AS THEY NAVIGATE THROUGH THE NASAL CAVITY. 2. A SPECIALIST INSERTS AN ENDOSCOPE IN ONE NOSTRIL UNTIL IT REACHES THE BACK OF NASAL CAVITY. A SMALL PIECE OF BONE IS REMOVED TO EXPOSE SPHENOID SINUS.
- THE SURGEON CUTS THE BACK WALL OF SPHENOID SINUS AND THEN THE DURA TO EXPOSE THE PITUITARY GLAND.
- THE SURGEON THEN REMOVES TUMOR OR TISSUE USING SPECIAL INSTRUMENTS.
- NEXT. A PIECE OF FAT IF TAKEN FROM THE ABDOMEN. THIS FAT GRAFT IS THEN USED TO FILL UP THE EMPTY SPACE LEFT AFTER THE REMOVAL OF TUMOR.
- A BONE GRAFT (OR A SYNTHETIC GRAFT) IS USED TO CLOSE THE BACK WALL OF THE SPHENOID SINUS. BIOLOGIC GLUE IS USED ON THIS GRAFT TO HELP IN HEALING AND PREVENTING LEAKAGE OF CEREBROSPINAL FLUID (CSF). SPLINTS ARE POSITIONED ON THE SIDE OF THE SEPTUM TO CONTROL BLEEDING AND SWELLING.
What happens after endoscopic transsphenoidal surgery?
The patient is moved to a postoperative recovery area (called PACU) where vital signs (blood pressure, respiration and heart rate) can be closely monitored. Painkillers are given as needed.
Once fully awake, the patient will be moved to another room. The patient will be asked to increase activity level by sitting in a chair or walking.
Patients may feel symptoms such as headache, nasal congestion or nausea. Medications will be given to controlling these symptoms if they occur.
CT or MRI scans will be taken a day after surgery. The patient will be allowed to go home about 24 to 48 hours after the surgery.