Preoperative tumour embolisation is a minimally-invasive procedure performed before selected brain or spinal tumour operations. Its purpose is to reduce the tumour's blood supply, so the surgeon may encounter less bleeding and have a clearer, safer operating field.
It is an additional treatment to surgery — not usually a replacement for removing the tumour.
What is Preoperative Tumour Embolisation?
Some tumours have many blood vessels supplying them. During surgery, these vessels may bleed significantly, making the operation more difficult. Embolisation blocks some of the arteries feeding the tumour before surgery.
A specially-trained doctor — an interventional neuroradiologist or neurointerventional specialist — guides a thin tube called a catheter through the blood vessels to the tumour. Small particles, medical glue, coils, or another approved material are then released to reduce blood flow to the tumour. The tumour is usually removed later by a neurosurgeon or spinal surgeon.
Embolisation is considered only when the tumour's blood supply can be safely reached and blocked without damaging normal brain, spinal cord, or nerve tissue. It is not suitable for every tumour — the decision is made jointly by the neurosurgical, oncology, and neurointerventional teams.
Symptoms
Symptoms usually come from the tumour itself rather than from the embolisation procedure.
Brain Tumour
- Headache — particularly if new or progressively worsening
- Seizures
- Weakness or numbness affecting one side of the body
- Difficulty speaking, understanding, or swallowing
- Changes in vision
- Problems with balance, coordination, or walking
- Personality, memory, or concentration changes
- Nausea or vomiting, especially with other neurological symptoms
Spinal Tumour
- Persistent back or neck pain
- Pain spreading into an arm, chest, abdomen, or leg
- Numbness, tingling, or altered sensation
- Limb weakness or heaviness
- Difficulty walking or poor balance
- Loss of bladder or bowel control
- Severe symptoms caused by pressure on the spinal cord or nerves
Symptoms vary according to the tumour's location, size, and effect on nearby nerves or the spinal cord.
Causes & Considerations
A tumour may arise from the brain, spinal cord, their coverings, or nearby tissues — or it may have spread from another part of the body.
Tumours sometimes considered for preoperative embolisation are highly vascular tumours, such as selected meningiomas, hemangioblastomas, paragangliomas, and certain spinal tumours or metastases. The exact type of tumour, its location, and its blood supply determine whether embolisation is possible.
Important factors considered before the procedure:
- Number and size of the tumour's feeding arteries
- Whether the feeding arteries also supply normal brain, cord, or nerves
- The tumour's location and accessibility
- Kidney function and ability to receive contrast dye
- Blood-thinning medicines or bleeding disorders
- Previous allergy to contrast material
- General health and ability to undergo anaesthesia or sedation
When to See a Doctor
Seek medical assessment for a new or worsening neurological symptom, especially:
- A seizure
- Sudden weakness, numbness, or difficulty speaking
- Progressive loss of vision
- New loss of balance or difficulty walking
- Persistent back pain with weakness or numbness
- Severe headache with vomiting, confusion, or drowsiness
After embolisation, seek urgent attention for:
- New weakness, numbness, facial drooping, or difficulty speaking
- New visual loss, severe confusion, or a seizure
- Sudden severe headache or repeated vomiting
- New or worsening leg weakness after spinal embolisation
- Loss of bladder or bowel control
- Heavy bleeding or swelling at the catheter-entry site
- Fever, severe pain, or coldness and colour change in the affected limb
Diagnosis & Planning
Before embolisation, the medical team needs to understand the tumour and map its blood supply. Tests may include:
- MRI of the brain or spine — shows the tumour's size, location, and relationship to the brain, spinal cord, and nerves.
- Contrast-enhanced MRI or CT — helps demonstrate tumour blood vessels and nearby structures.
- Digital Subtraction Angiography (DSA) — a catheter-based X-ray examination that shows the tumour's feeding arteries in detail and identifies arteries supplying normal brain or spinal cord.
- Blood tests — kidney function, blood count, and clotting tests.
- Clinical & neurological examination — checks strength, sensation, vision, coordination, and walking.
Treatment / Procedure
Before the Procedure
The treating team will review your imaging, explain the plan, and check allergies, kidney function, and medicines. They will advise when to stop eating and drinking and whether local anaesthesia with sedation or general anaesthesia will be used.
Important: Do not stop aspirin, clopidogrel, warfarin, apixaban, or any other blood thinner unless your treating doctor specifically instructs you to.
During the Procedure
- 1
The patient is monitored closely and receives anaesthesia or sedation.
- 2
A small tube is inserted into an artery, commonly in the groin or wrist.
- 3
The catheter is guided through the blood vessels to the arteries feeding the tumour.
- 4
Angiography confirms the tumour's blood supply and checks for vessels supplying normal tissue.
- 5
Embolic material — particles, liquid embolic, glue, or coils — is delivered through the catheter.
- 6
Repeat angiography confirms that blood flow to the intended part of the tumour has been reduced.
- 7
The catheter is removed and pressure or a closure device is applied to the entry site.
The procedure may take several hours, depending on the tumour's location and the complexity of its blood supply.
Benefits
- Less bleeding during tumour surgery
- Better visibility for the surgeon
- Easier separation of the tumour from nearby structures
- Shorter or more controlled surgery in selected cases
- Possible softening or partial shrinkage of the tumour before removal
These benefits are not guaranteed. Evidence of benefit varies by tumour type and location, so embolisation is used selectively.
After the Procedure
The patient is observed in a recovery or intensive-care setting, depending on the tumour and overall condition. The team checks strength, sensation, speech and vision (and leg function after spinal embolisation), the catheter-entry site, blood pressure, pulse, and kidney function. Mild headache, nausea, fatigue, or discomfort at the catheter site may occur temporarily. Surgery may be performed soon after embolisation or at a later planned time, depending on the treating team's plan.
Conclusion
Preoperative embolisation can make surgery safer and more controlled for selected brain and spinal tumours with a rich blood supply. It works by reducing blood flow to the tumour before surgery, but it does not usually remove the tumour or replace definitive tumour treatment. The procedure requires careful imaging, detailed artery mapping, and close coordination between the neurosurgeon, oncologist, anaesthetist, and neurointerventional specialist — always balancing the expected reduction in surgical bleeding against the small but serious risk of affecting normal brain, spinal cord, or nerve blood supply.