BRAIN TUMOUR SURGERY: OVERVIEW
A brain tumour is characterized by an abnormal mass or growth of cells in the brain. While some tumours may be benign and non-cancerous, there are others which are significantly malignant and cancerous. Basically, there are two types of brain tumours – one that originates in the brain and are called primary tumours; and second are the ones that begin in any other part of the body but spread to the brain – these types of tumours are called secondary metastatic brain tumours. However, the intensity of the condition depends on the type of tumour, the location and the rate of growth. These options also determine the course of treatment for a brain tumour.
Diagnosis of Brain Tumour
Based on symptoms per case, the doctor might suggest a few diagnostic procedures to study the conditions. The diagnosis methods for brain tumour include:
- Neurological exam
- Imaging tests
- CT or PET scan
- MRI scanning
Post diagnosis, depending on the size, location and growth of the tumour – the doctor will suggest a treatment method including surgery, radiation therapy, radiosurgery, chemotherapy and targeted drug therapy. However, in most cases, surgery is the primary mode of treatment of brain tumour.
Brain Tumour Surgery
A brain tumour surgery might appear as a frightening procedure, but it is the most effective method to treat brain tumours while causing minimal damage. Brain tumour surgery is primarily used in treating malign tumours and in the case of malignant tumours – are used in combination with other treatment options such as radiation and chemotherapy. The basic goals of brain tumour surgery include:
- Remove all or most of the tumour
- Relieve symptoms caused by the tumour and enhance the quality of life
- Relieve the intracranial pressure created by the tumour
- Remove a part of the tumour to slow the growth
- Drain any build-up of fluid in the brain
- Make other treatments such as chemotherapy accessible
- Help diagnose a brain tumour
The type of surgery and surgical method varies per case. However, brain tumour surgery is performed only when the tumour is located in a place which is accessible easily. The basic surgery is performed to remove as much of the tumour as possible and relieve symptoms. This type of brain tumour surgery is called Craniotomy. ‘Crani’ implying skull and ‘otomy’ meaning cutting into; therefore a craniotomy involves cutting into the skull to remove the tumour.
The doctor will perform several tests before the surgery and would restrict all non-steroidal anti-inflammatory medicines, as well as blood thinners. Other lifestyle habits such as tobacco, alcohol, smoking, etc. also will be restricted. During the night before the surgery, the patient is asked to avoid eating or drinking anything.
A craniotomy is performed while keeping the patient under the influence of general anaesthesia. Then a portion of the scalp is shaved to make an incision to enter the skull and remove a piece of bone to access the area of the brain over the tumour. The surgeon opens the outermost layer of the brain tissue, locates the tumour and then removes/resects it. Once, the tumour is removed, the surgeon replaces the part of the brain or bone; this is called a flap which is secured with small metal brackets. Once, this is replaced, the surgeon stitches the scalp.
In a conventional craniotomy, the surgeon relied on pre-operative scans and their knowledge of anatomy to locate and treat the tumour. However, in stereotactic surgery, the surgeon relies on a computer to locate the tumour and guide them to it. A craniotomy involves using different tools to remove the tumour, such as:
- A scalpel
- An ultrasound to shrink the size of the tumour and then remove it through a suction process
- A microscope to differentiate between healthy cells and tumour
- A blue fluorescent light which enables the surgeon to clearly see the edges of the tumour
Craniotomies differ in size and complexity. In some cases, the surgeon may perform an awake craniotomy where the lesion is very close to a critical area of the brain such as speech. In this surgery, the patient is asleep till the bone opening but is awakened later to help the surgeon precisely map areas of risk. The patient is asked to read, talk or move a part of the body, while a probe is placed on the brain surface to detect the area correctly. This process is also called, Brain Mapping and helps to identify sensitive areas of the brain which need to be avoided and protected.
In some cases, the tumours are small and thus, can be easily removed from the brain tissue. But in many other cases, it is very difficult to separate the tumour from the surrounding tissue or they tend to be located in sensitive areas of the brain – which makes the surgery risky and complicated. In the latter case, the surgeon aims to remove as much a part of the tumour which is not risky and is relatively safe. Even removing a portion of the brain tumour helps to relieve symptoms. However, like other surgeries, even brain tumour surgery has risks associated with it.
Risks of a Brain Tumour Surgery
Some of the common risks linked to brain surgery, specifically a craniotomy include:
- Blood clots
- Anaesthesia reactions
- Swelling of the brain
- Nerve damage
- CSF leak
- Loss of some mental functions
Overall, a brain tumour surgery is highly effective and often the primary course of treatment; though the recovery period may extend up to 8 weeks with several follow-up appointments.