Craniotomy in Cats

Craniotomy is a complex surgical procedure used to remove brain tumors and other intracranial lesions in cats. Craniotomy is often recommended in addition to other therapies, most notably radiation and medication. Older cats – particularly those that are male and over twelve years old – have a higher chance of developing brain tumors compared to younger cats. Craniotomy tends to be more effective in treating feline brain tumors because it is easier for surgeons to fully remove lesions from the brain tissue.

Only a specialized veterinary neurosurgeon can perform craniotomy. The exact surgical approach of craniotomy will vary based on the type and location of the tumor. The general steps of craniotomy are outlined below.

1. Prior to surgery, the cat will undergo extensive testing to locate the tumor and ensure anesthetization is safe.
2. The cat will be anesthetized and prepped for surgery.
3. The cat’s head will be placed into a special craniotomy stand to ensure stabilization.
4. The neurosurgeon will make the initial skin incision before using a special drill to operate on the skull and exposing the dura matter.
5. An MRI will be conducted to locate the tumor via an MRI biopsy needle.
6. The surgeon will use the MRI image as a guide during surgery.
7. Aided by a surgical microscope, the surgeon will use a special ultrasonic aspirator machine to destroy the inner part of the tumor. This will also decompress the tumor.
8. Blood vessels surrounding the tumor are then resected so that the tumor can be removed.
9. MRIs will be taken throughout the surgery to ensure no bleeding has occurred or no part of the tumor has been left in place.
10. A skin graft will be placed while the dura matter is sutured prior to the administration of suture glue, which prevents the leakage of cerebrospinal fluid.
11. The skull will then be repaired and the initial skin and muscle incisions will be sutured.
12. Immediately following surgery, cats will be given intravenous medications that decrease brain pressure.
13. Cats may be hospitalized for a period of three to seven days following surgery.

The efficacy of craniotomy will vary based on the type of cancer or lesion, the severity of the underlying condition, and the overall health of the cat prior to surgery. In general, craniotomy is considered more effective in cats than dogs, because brain tumors can be easily and fully removed from the brain tissue. However, complete removal is not always possible due to the risk of damaging healthy tissue. The rate of postoperative mortality in cats that have undergone craniotomy is 19%. Cats that are diagnosed and treated quickly have a better chance of surviving than cats that have an aggressive type of cancer that is severe or has spread rapidly.

Owners should follow their surgeon’s postoperative care instructions very carefully. Cats should rest, not engaging in activity for the full duration of the recovery period. If swelling or drainage occurs near the incision site, owners should contact their veterinarian immediately. Follow-up appointments will be scheduled with ten to fourteen days to remove sutures. A follow-up appointment is typically scheduled within eight weeks following surgery to monitor healing. Additional appointments will be scheduled to administer additional treatments according to the cat’s needs.

The average cost of craniotomy will vary based on standards of living and additional costs incurred, including postoperative medications, diagnostics tests, and additional treatments. On average, the cost of craniotomy – including hospitalization, supportive care, and intraoperative imaging – ranges from $4,000 to $6,500.

In some cats, craniotomy may not be possible or safe. In these cases, radiation treatment and conservative treatment with medication, most commonly steroids and anticonvulsants, is typically recommended. Additionally, craniotomy is an expensive procedure which is incredibly invasive for the cat. Approximately 50% of cats that undergo craniotomy will still survive two years later. 

Complications are possible with any type of surgery, particularly with brain surgery. Complications of craniotomy in cats include, but may not be limited to:

• Damage to healthy brain tissue 
• Recurrence of the tumor
• Anemia
• Anesthetic death

Anemia is the most common postoperative complication, and it may play a role in postoperative mortality. Anesthetic death is rare, particularly in animals that have been evaluated for anesthetization prior to surgery.

It is difficult to prevent most types of brain tumors, as they are often a geriatric condition associated with aging. Cats that have undergone craniotomy should not be bred, as brain tumors can be attributed to genetics.