Brain Surgery Information:

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CHAPTER 18: COMPLICATIONS OF TREATMENT

No treatment option is free of risk of complications. The risk of complications is dependent on many factors including:

·  The size and location of the lesion: As a rule of thumb, larger lesions and lesions located in the deep parts of the brain, or in the brain stem carry higher treatment-related risks.

·  How the lesion presented at the time of treatment: For example, a patient with a metastatic brain tumor presenting with a large brain hemorrhage within the tumor bed may have a lower chance of a good outcome. The same can be said for a patient with a brain aneurysm who presents following rupture of the aneurysm. These outcomes are more dependent on the clinical condition of the patient prior to treatment, rather than the treatment itself.

·  The type of treatment offered: For a certain lesion in a certain patient, it may be deemed by the physician to be safer, in the short term at least, to treat the lesion with endovascular therapy or SRS, when appropriate, as opposed to surgery.

·  The age and general medical condition of the patient: In general, older patients, particularly over the age of 75, or patients with multiple medical problems such as active heart, lung or kidney disease, or diabetes mellitus, are at higher risks of post-treatment complications.

·  The experience of the neurosurgeon. The rate of complications “quoted” to a patient by his or her neurosurgeon should be his or her personal complication rates rather than those reflected in the literature, which may be higher or lower in comparison.

·  Previous treatment: A brain lesion treated by previous open surgery or SRS or endovascular therapy may be associated with higher complication rates following subsequent treatment.

 

For the majority of brain conditions coming to open surgery, radiosurgery, or endovascular surgery, there is a 90-95% or better chance that treatment will be without significant complication. However, the final percentages are subject to discussion between the patient and the surgeon, and should take into consideration the factors mentioned above.

What types of treatment complications can occur?

Any complication a patient can think of can occur with any treatment. However, the chances of such complications occurring are usually low. Some general points are as follows:

·  Open surgical complications: Certain complications apply to patients undergoing open surgery, as their treatment and postoperative care is usually more complex and prolonged compared with patients undergoing endovascular or radiosurgical treatment. General medical complications among patients undergoing open surgery include death under anesthesia from some very rare reaction to anesthetics. The chance of this is well under 1%. Other relatively rare complications include DVT, aspiration pneumonia, and PE. New seizures can also occur postoperatively. If any seizures do occur, they are usually temporary, lasting in the order of days to a few months. Major stroke or other brain tissue injury resulting in some permanent neurological disability such as impaired eyesight, double vision, speech and swallowing difficulty, facial and/or limb weakness or paralysis, incoordination and imbalance can also occur. A final and more specific discussion of the chances of any of these occurring is deferred to a patient’s treating physician.

·  Complications of endoscopic neurosurgery: Bleeding and infection are the main risks, but sometimes incomplete tumor removal occurs. In some instances, impairment of memory function can occur during navigation of the endoscope through the brain, with some form of injury to a structure known as the fornix. These risks should be discussed with the neurosurgeon.

·  WBRT and radiosurgical complications: These include early swelling and/or redness around soft tissues of the scalp and/or face tissue through which the radiation beams have passed. It does not mean that the brain itself is swelling. Soft tissue swelling occurs fairly commonly after SRS, and usually in the first few days to a week following radiosurgery. It is treated conservatively with over-the-counter anti-inflammatory medications, walking about, and ice-packs. This sort of swelling typically begins to settle within a few days. If a head frame was used for SRS, the pin sites can swell and become red too. These findings do not necessarily imply infection, and should settle within a few days with conservative treatment as indicated above. If pus oozes from the pin sites, a patient should see his or her doctor. Some patients also complain of nausea and headaches soon after SRS, but these symptoms tend to settle on their own within days. Hair loss is very rare with SRS unless the lesion being treated is very close to the scalp. It may be more common with WBRT. If hair loss does occur with SRS, it is usually in a patch and will typically grow back. Hair loss with WBRT, and especially if additional chemotherapy is given, tends to be more diffuse and hair regrowth slower. Delayed swelling within the brain, referred to as radiation necrosis, is a potentially serious complication that can occur several months after radiation therapy. It occurs in some patients following radiation and can present with signs of raised ICP and any type of neurological deficit. It is frequently treated with steroids and sometimes by open surgery. WBRT and SRS can also damage neighboring normal structures, including brain tissue and cranial nerves. For SRS, the radiation tends to taper off from the main target and into tissue in the vicinity of the radiation “field”, albeit at a lower dose than for the target itself. New neurological impairment, which is unlikely to occur but can occur, should be reported to the doctor. For example, there may be delayed visual or hearing problems, or facial weakness, if the nerves for vision and hearing or facial muscle movement were near the primary radiation target. WBRT can cause cognitive impairment and, whenever possible, is avoided in younger persons. The other main complication of WBRT or radiosurgery is that it may fail to control the pathology for which it is being administered. For example, an irradiated tumor or AVM may continue to grow and/or cause problems despite SRS. It may be radiation-resistant. In very rare instances, a second tumor can form that may be the result of the radiation itself.

·  Endovascular complications: These include infection and an expanding painful blood clot at the site of groin puncture, both of which are relatively uncommon. Other complications include a temporary neurological impairment or a permanent stroke at the time of catheter navigation and endovascular therapy. This can arise from an injury such as dissection or rupture of a vessel wall, or from unexpectedly extensive clot forming within the treated vessel territory, and sometimes breaking off to other parts of the brain circulation. In some cases, endovascular therapy may not fully treat the condition, and repeated endovascular surgery or open surgery may be required to complete the treatment.

·  Chemotherapy complications: There are many different side-effect profiles for chemotherapy agents used alone or in some combination. Some are tolerated better by certain patients than others. As chemotherapy medications tend to target rapidly dividing cells that are typical of high grade tumors or cancers, and because some of the body’s cells such as in the gut, hair and bone marrow are also rapidly dividing, chemotherapy agents also carry the potential to damage these normal cells. Relatively common side effects include nausea, vomiting, and gastrointestinal (GI) upset. There may be hair loss, particularly if the patient has both chemotherapy and radiation therapy. There is often some form of reduced white cell production referred to as leucopenia, and sometimes more generalized bone marrow impairment referred to as myelosuppression can occur. This can lead to reduced red blood cell production or anemia, and increased problems with infection and blood clotting. Chemotherapy agents can also damage organs in the body such as the kidney, liver, and heart. They may also damage the nerves of the limbs or peripheral nervous system, resulting in sensory and muscle or motor functional impairment from peripheral neuropathy. Rare severe toxic reactions to standard doses and combinations of chemotherapy agents have been reported. It is recommended that a chemotherapy patient’s physician regularly screen the patient’s blood for development of abnormalities in the complete blood count, and kidney and liver function tests. Finally, regarding brain chemotherapy implants such as Gliadel® wafers, brain swelling and local wound problems can occur with these, requiring their surgical removal.

·  Steroid complications: Steroid therapy complications include high blood pressure or hypertension, sodium and fluid retention or damming in the body, GI upset or frank GI system disease, confusion, and elevated mood referred to as euphoria. Cushing’s syndrome can also occur with long-term steroid use, usually in the order of months. This is associated with swelling of the face, increased facial and body hair, muscle wasting, weight gain, poor and bruised skin quality, hypertension, and so forth. Steroids can also cause suppression of the immune system, with increased likelihood of general infections, poorer wound healing and wound infections. In some instances, chronic steroid use can lead to muscle weakness and wasting known as steroid myopathy. The patient’s white cell count can also rise with steroid use. Finally, abrupt stopping of steroids, that is, without true tapering or gradual weaning, in a patient who has been on steroids for at least several days can cause a syndrome of steroid withdrawal which includes nausea, vomiting, a feeling of generalized weakness and unwellness, and depression.