Treatment of brain aneurysm

Treatment to seal off a weakened, balloon-like bulge in a brain blood vessel (an aneurysm) to stop it bleeding, either from inside the vessel (coiling) or with an operation (clipping).

✓ Medically reviewed by a GMC-registered consultant · last reviewed September 2026 · next review September 2027 · how we review

In short

Treatment seals off a weakened bulge in a brain blood vessel so it cannot bleed, either from inside the vessel (coiling) or with an operation (clipping).
Not every aneurysm needs treating — many small, unruptured ones are monitored, because the procedure can carry more risk than leaving the aneurysm alone.
When an aneurysm has burst or is likely to, treatment is usually urgent; the choice between coiling and clipping is made by a specialist team for your specific aneurysm.
The procedure itself carries a real risk of stroke or bleeding, which must be weighed honestly against the risk of the aneurysm bursting.

A plain-English summary. The detail — including risks and recovery — is below.

At a glance

TypeBrain blood-vessel procedure (coiling) or operation (clipping)

AnaestheticGeneral anaesthetic

How long it takesOften around 1 to 3 hours, depending on the method and aneurysm

Hospital stayA short stay for planned coiling; longer, often with intensive care, after a bleed or clipping

Time off workFrom a couple of weeks after planned coiling to weeks or months after a bleed

When you'll see resultsThe aneurysm is sealed at the time; recovery depends on whether it had already bled

On the NHS?Almost always done on the NHS in a specialist neurosurgery/neuroradiology centre, often urgently

A general guide. Your surgeon will give you advice for your situation.

Best fit

Seals the aneurysm so it can no longer bleed, or bleed again

Pause if

Your aneurysm is small and low-risk, so monitoring with scans is safer than a procedure.

Main recovery point

You are watched closely, often in intensive care or a high-dependency unit, especially after a bleed or clipping. The team checks for any change in your...

Good aftercare

Close monitoring after the procedure, with clear written warning signs and an emergency plan (call 999 for a sudden severe headache).

First hours to days

You are watched closely, often in intensive care or a high-dependency unit, especially after a bleed or clipping...

First few weeks

After planned coiling, many people return to gentle activity within a couple of weeks. After a clipping or a...

Weeks to a few months

After a bleed, recovery of energy, concentration and any affected functions continues over this time. Wound...

Ongoing

You are usually followed up with scans to check the aneurysm stays sealed. Driving may be restricted for a period...

Medical line illustration of brain and neck blood vessels for Treatment of brain aneurysm. — Illustration only - not a diagnosis, medical advice or a promise of result. Your anatomy and treatment plan may differ. Vuemedics does not publish before-and-after photos.

What is treatment of a brain aneurysm?

A brain aneurysm is a weak, balloon-like bulge in the wall of a blood vessel in or around the brain. Most cause no symptoms and are found by chance. The danger is that an aneurysm can burst and bleed (a subarachnoid haemorrhage), which is a medical emergency. Treatment aims to seal the aneurysm off so blood can no longer enter it, preventing a bleed or a further bleed.

There are two main ways to do this. Endovascular coiling is done from inside the blood vessels: a fine tube is passed up from an artery (usually in the wrist or groin) to the aneurysm, and tiny platinum coils are packed inside it so blood clots and seals it off. Surgical clipping is an operation (a craniotomy) where the surgeon places a small metal clip across the neck of the aneurysm. Some aneurysms are treated with a flow-diverting stent or a small mesh device instead.

The most important point is that treatment is not always needed. Many small, unruptured aneurysms are simply monitored with scans, because the risk of the procedure can be higher than the risk of the aneurysm bursting. When an aneurysm has already burst, or is judged likely to, treatment is usually urgent. The decision is made by a specialist team weighing the risk of treating against the risk of leaving it.

The right method and the risks depend heavily on the size, shape and position of the aneurysm, whether it has bled, and your general health.

Types & techniques

There isn't one single operation. The right approach depends on you — which is something to discuss with your surgeon.

Endovascular coiling

Done from inside the blood vessels through a tube passed up from the wrist or groin. Tiny coils are packed into the aneurysm so it clots and seals off, without opening the skull.

Surgical clipping

An operation (craniotomy) where a small metal clip is placed across the neck of the aneurysm to stop blood entering it. Used when this is the safer or more durable option.

Flow-diverting stent

A fine mesh tube placed across the aneurysm's neck inside the vessel, which diverts blood flow past the aneurysm so it gradually seals. Usually needs blood-thinning medicines afterwards.

Mesh (WEB) device

A small mesh device placed inside certain wide-necked aneurysms to block flow into them, as an alternative to coils.

Monitoring (no procedure)

For many small, unruptured aneurysms, regular scans and blood-pressure control are chosen instead, because the risk of treatment may outweigh the risk of a bleed.

Coiling, clipping and monitoring compared

	Coiling	Clipping / monitoring
How	From inside the vessel	Open operation, or scans only
Opens the skull	No	Clipping yes; monitoring no
Often chosen for	Many ruptured and unruptured	Some shapes, or low-risk small ones
Needs retreatment	A little more often than clipping	Clipping rarely; monitoring as needed
Decision	Made with a specialist team	Made with a specialist team

Whether to coil, clip or monitor depends on the aneurysm's size, shape and position, whether it has bled, and your health. For ruptured aneurysms, large trials found coiling gave better recovery for many patients, but clipping is still better for some. A specialist team should explain the trade-offs.

Preparing for your surgery

Ask the specialist team why treatment is recommended now, or why monitoring is being suggested instead, and what the risks are either way.
Expect detailed scans of the blood vessels (such as CT or MR angiography, or a catheter angiogram) before a decision.
Tell the team about all medicines, especially blood thinners and blood-pressure medicines, and any allergies.
If a stent is planned, ask about the blood-thinning (antiplatelet) medicines you will need and for how long.
Discuss whether coiling or clipping is being recommended for your aneurysm, and why.
Arrange support at home and time off, which is short for planned coiling but longer after a bleed.
Ask about driving rules afterwards, as these can be affected, especially after a bleed or seizures.

What happens

Both coiling and clipping are usually done under general anaesthetic, so you are asleep. In coiling, a specialist passes a fine tube up through an artery in your wrist or groin and guides it to the aneurysm using X-ray imaging, then packs tiny coils (or places a stent or device) inside or across it so blood can no longer fill it. There is no cut on the head.

In clipping, the surgeon performs a craniotomy — temporarily removing a window of skull bone — and places a small metal clip across the neck of the aneurysm before replacing the bone. This is a bigger operation.

A planned coiling procedure often takes a few hours and may need only a short stay. After a burst aneurysm, or after clipping, you are usually looked after closely, often in intensive care for a time, and recovery is longer. The team monitors you carefully for any signs of bleeding or reduced blood flow to the brain.

Is this operation right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

May not be suitable if…

Your aneurysm is small and low-risk, so monitoring with scans is safer than a procedure.
The risk of treating outweighs the likely risk of the aneurysm bursting, given its size, shape and position.
Your general health makes a general anaesthetic or major surgery too dangerous.
One method (coiling or clipping) is unsuitable for your aneurysm's shape, so the other or monitoring is chosen.

Delay surgery if…

There is an active infection or another treatable problem to sort first, where the situation is not an emergency.
Blood-thinning or blood-pressure medicines need safe planning before a procedure.
Further scans (angiography) are needed to plan the safest method.
For a small unruptured aneurysm, more time is reasonable to weigh up treatment versus monitoring.

Alternatives to discuss

Monitoring with regular scans and blood-pressure control for many small, unruptured aneurysms.
Choosing coiling instead of clipping, or vice versa, depending on the aneurysm.
A flow-diverting stent or mesh device for certain aneurysm shapes.
Managing risk factors (blood pressure, smoking) to reduce the chance of a bleed.
A second specialist opinion before committing to a procedure.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

What matters most to me?

Think about symptoms, daily life, work, caring responsibilities, sport, fertility, travel, appearance and anxiety — the right choice depends on your priorities, not just the medical facts.

What are all my options?

Ask about waiting, monitoring, medicines, rehabilitation, a smaller or larger procedure, a different test, NHS referral, or a second opinion where that would help.

What would make me pause?

Active infection, pregnancy, unstable medical problems, smoking, medicines that increase bleeding, poor support at home, or feeling pressured are all reasons to slow down and get tailored advice.

What happens if I do nothing today?

For some problems, waiting is safe; for others, delay can make treatment harder. A good consultation should explain the trade-off in plain English.

Anaesthetic choices

The safest option depends on the operation, your health, the facility and your surgeon/anaesthetist. Ask what is planned and why.

General anaesthetic

Both coiling and clipping are usually done fully asleep under a general anaesthetic.

Benefits

Seals the aneurysm so it can no longer bleed, or bleed again
Coiling avoids opening the skull and often allows a quicker recovery for planned cases
Can be life-saving after an aneurysm has burst
Reduces the risk of a devastating brain bleed in carefully selected people
Allows a specialist team to choose the safest method for your specific aneurysm

Risks & complications

More common

Bruising or tenderness where the tube went in (wrist or groin) after coiling
Headache and tiredness in the early period
After clipping: swelling, bruising and a strange feeling around the wound for some weeks

Less common

A stroke-like problem during or after the procedure (weakness, numbness, speech, vision or balance changes), which may be temporary or lasting
The aneurysm not being fully sealed, or filling again later, needing further treatment
Seizures (fits), especially after clipping or a bleed
Infection, or a blood clot related to a stent

Rare but serious

The aneurysm bursting during the procedure
Serious bleeding or a major stroke
Serious complications that can be life-threatening; death is uncommon but possible and depends heavily on whether the aneurysm had already bled

The hardest part of this decision is that the procedure itself carries a real risk of stroke or bleeding, which has to be weighed against the risk of the aneurysm bursting if left alone — and both depend on the aneurysm's size, shape and position. Ask the team to be specific about your aneurysm's likely yearly risk of bleeding and the risk of the procedure, so you can weigh them together.

Published figures to discuss

Risk depends heavily on whether the aneurysm has already bled, and on its size, shape and position. The hardest comparison is between the risk of the procedure and the risk of the aneurysm bursting if left, which is why these decisions are made by specialist teams. The figures below come from research studies and are a guide to the scale of risk only; they vary between aneurysms and centres, and your team should give you numbers for your situation.

Figure	Reported range	How to interpret it	Source / confidence
Aneurysm bursting during treatment of an unruptured aneurysm	Around 1 in 100 in one study series	From research data; the risk is higher when an aneurysm has already bled.	ISAT — long-term outcomes of clipping versus coiling (PMC)ncbi.nlm.nih.govPublished figure
Serious complication (disability or death) from coiling a ruptured aneurysm	Around 6 in 100 in one large series	Much of the overall outcome after a bleed is driven by the bleed itself, not only the procedure.	ISAT — long-term outcomes of clipping versus coiling (PMC)ncbi.nlm.nih.govSource-linked context
Being dead or dependent one year after a burst aneurysm	Around 23 in 100 after coiling versus 31 in 100 after clipping in the ISAT trial	Reflects outcomes after a bleed; for unruptured aneurysms treated electively, outcomes are usually much better.	Guide sourcesClinical context
Aneurysm bleeding again in the long term after treatment	Around 0.5 in 100 after clipping and 1.5 in 100 after coiling in ISAT long-term follow-up	Why follow-up scans are arranged, especially after coiling.	ISAT — long-term outcomes of clipping versus coiling (PMC)ncbi.nlm.nih.govSource-linked context

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

Recovery — what to expect, and when

Recovery depends enormously on whether the aneurysm had already bled. After a planned coiling of an unruptured aneurysm, recovery is often quick. After a burst aneurysm, recovery can take weeks to months and may involve rehabilitation.

First hours to days

You are watched closely, often in intensive care or a high-dependency unit, especially after a bleed or clipping. The team checks for any change in your symptoms. After planned coiling, the wrist or groin site is checked and you rest before going home.

First few weeks

After planned coiling, many people return to gentle activity within a couple of weeks. After a clipping or a bleed, the wound heals, energy returns gradually, and some people need physiotherapy, speech therapy or other rehabilitation.

Weeks to a few months

After a bleed, recovery of energy, concentration and any affected functions continues over this time. Wound bruising fades over months. Any further treatment or monitoring is planned.

Ongoing

You are usually followed up with scans to check the aneurysm stays sealed. Driving may be restricted for a period, especially after a bleed or seizures, and you must follow the rules of the DVLA (in England, Scotland and Wales) or the DVA (in Northern Ireland). Blood pressure and lifestyle are managed to protect the vessels.

What's normal — and not a worry

Headache and tiredness in the early period
Bruising at the wrist or groin after coiling
After clipping: swelling, bruising and a numb or tight feeling around the wound
Emotional ups and downs, which are common, especially after a burst aneurysm

Aftercare

Take any blood-thinning (antiplatelet) or blood-pressure medicines exactly as prescribed and do not stop them suddenly.
After coiling, look after the wrist or groin site as advised and avoid heavy lifting at first.
After clipping, follow wound-care advice and keep the area clean and dry.
Rest at first and build up activity gradually as advised.
Do not drive until your team confirms it is allowed and you have followed the rules of the DVLA (in England, Scotland and Wales) or the DVA (in Northern Ireland), especially after a bleed or seizures.
Attend follow-up scans to check the aneurysm stays sealed.
Know the warning signs of a bleed and call 999 for a sudden, severe 'thunderclap' headache.

Before-surgery checklist

All medicines, including any blood thinners, collected and clearly understood
A list of warning signs and an emergency plan (call 999 for a sudden severe headache)
Someone to help at home in the early days
Transport sorted, knowing you may not be able to drive
Follow-up scan and clinic appointments noted
Blood-pressure plan understood
Questions written down for your follow-up

Scars and how they heal

After coiling there is usually just a small puncture site at the wrist or groin, which may bruise and settles over a couple of weeks, leaving little or no mark. After clipping there is a scar on the scalp, usually hidden within the hairline where possible, which fades to a thin pale line over months as hair grows back.

⚠ Get urgent help if…

A sudden, severe headache, often described as the worst ever — call 999 (possible aneurysm bleed)
New weakness, numbness, or problems with speech, vision or balance
A stiff neck, sensitivity to light, or repeated vomiting
A seizure (fit)
Drowsiness, confusion, or being difficult to wake
At the wrist or groin: a rapidly swelling, very painful or cold limb, or bleeding that won't stop
Increasing redness, swelling or discharge from a wound, or a high temperature

Who to contact: your surgeon or clinic first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your surgeon gives you.

Results & realistic expectations

A good result means the aneurysm has been sealed so blood can no longer enter it, reducing the risk of a bleed or a further bleed. After a planned procedure on an unruptured aneurysm, many people recover quickly. After a burst aneurysm, the result is also shaped by the effects of the bleed itself, and recovery can take longer.

Treatment cannot undo damage already caused by a bleed, and it cannot guarantee that an aneurysm will never reopen or that a new one will not form, which is why follow-up scans are important. The realistic goal is set with your specialist team and depends on whether the aneurysm had bled and on its size, shape and position.

How long it lasts

Most treated aneurysms stay sealed, but coiled aneurysms can sometimes fill again over time and may need further treatment, which is why follow-up scans are usual. Clipping is durable but is a bigger operation. People who have had one aneurysm have a somewhat higher chance of having or developing another, so monitoring and good blood-pressure control matter long term. Your team will explain how you will be followed up.

Combining with other procedures

Treatment is usually one part of a wider plan managed by a specialist neurovascular team. After a burst aneurysm, it is combined with careful monitoring for complications and often rehabilitation. Blood-pressure control, stopping smoking and managing other risk factors help protect the blood vessels. If a stent is used, blood-thinning medicines are part of the plan.

Follow-up & long-term care

You will be followed up by your neurovascular team, usually with scans to check the aneurysm stays sealed, and with monitoring of blood pressure and any other aneurysms. Rehabilitation may continue after a bleed. Any warning signs — especially a sudden severe headache, new weakness, a seizure or a stiff neck — should prompt urgent contact, and a sudden 'thunderclap' headache means calling 999.

Take blood-thinning or blood-pressure medicines exactly as prescribed.
Attend follow-up scans to check the aneurysm stays sealed and to monitor for any new one.
Keep blood pressure well controlled and stop smoking, to protect the blood vessels.
Follow the driving rules of the DVLA (in England, Scotland and Wales) or the DVA (in Northern Ireland), which may apply for a period after a bleed or seizures.
Report any sudden severe headache or new neurological symptoms urgently.

Revision and secondary surgery reality

Coiled aneurysms can fill again over time and may need further coiling or treatment.
An aneurysm sometimes cannot be fully sealed in one attempt, needing a further procedure.
People who have had one aneurysm may develop another, needing ongoing monitoring.
A stent or flow diverter needs blood-thinning medicines and carries its own small clot risk.

Ask your surgeon for their own revision rate, what counts as a revision, and what is included in the written aftercare policy.

What good aftercare looks like

Close monitoring after the procedure, with clear written warning signs and an emergency plan (call 999 for a sudden severe headache).
Follow-up scans to confirm the aneurysm stays sealed, and monitoring for any new aneurysm.
Clear advice on blood-thinning medicines if a stent is used, and on blood-pressure control.
Access to rehabilitation after a bleed, with support for you and your family.
Clear advice on driving, work and lifestyle, and a named team to contact.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

Brain aneurysm treatment is overwhelmingly an NHS service, so private cost questions arise rarely
Where private care applies: the surgeon's, interventional neuroradiologist's and anaesthetist's fees
The method used (coiling, clipping, stent or device) and the complexity of the aneurysm
Coils, stents or devices used
Hospital stay, including any intensive care, and imaging (angiography)
Blood-thinning medicines if a stent is used
Follow-up scans and any rehabilitation

Make sure your written quote includes

The named surgeon's or neuroradiologist's fee and the anaesthetist's fee
The hospital fee, including any intensive care stay
Imaging (angiography) and any coils, stents or devices
Blood-thinning medicines and follow-up scans included
What happens, and who pays, if a complication or readmission occurs
How retreatment would be arranged and funded if the aneurysm refills
Cancellation and rescheduling terms

On the NHS? Brain aneurysm treatment is almost always carried out on the NHS in specialist neurovascular centres, often urgently; private treatment is uncommon, though people may seek a private second opinion about an unruptured aneurysm.

You're entitled to your total cost in writing — including aftercare and any revision — before you decide.

Choosing a surgeon safely

Check your surgeon is on the GMC Specialist Register for this area.
Make sure they practise at a CQC-registered location, and look for membership of bodies like BAAPS or BAPRAS.
You're entitled to a two-stage consent process with time to reflect (a cooling-off period). The surgeon who will operate must consent you — not a salesperson.
Be wary of pressure: time-limited offers, discounts or deposits taken before you've had time to think are red flags, not bargains.
You're entitled to your total cost in writing — including aftercare and any revision — before you decide.

How Vuemedics verifies every consultant →

Questions to ask your medical professional

Take this to your consultation. A good surgeon will welcome every one of these.

What is my aneurysm's likely yearly risk of bleeding if left, and what is the risk of the procedure?
Are you recommending coiling, clipping or monitoring for me, and why?
If a stent is used, what blood-thinning medicines will I need and for how long?
What are my specific risks given the size, shape and position of my aneurysm?
How will I be followed up, and how likely is it to need treating again?
What are the rules for driving, blood pressure and daily life afterwards?
Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
Will you be the surgeon who carries out my operation, and who looks after me afterwards?
What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
What does a realistic result look like — and what can this operation not achieve?
What are my options, including waiting, doing nothing for now, or choosing a different approach?
Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Frequently asked questions

Does every brain aneurysm need treating?

No. Many small, unruptured aneurysms are simply monitored with scans and blood-pressure control, because the risk of the procedure can be higher than the risk of the aneurysm bursting. Treatment is usually for aneurysms that have bled or are judged likely to. A specialist team weighs this up with you.

What is the difference between coiling and clipping?

Coiling is done from inside the blood vessels through a tube, without opening the skull, by packing the aneurysm with tiny coils. Clipping is an operation that places a metal clip across the aneurysm's neck. Which is better depends on the aneurysm; your team will explain why one is recommended for you.

Is it done on the NHS or privately?

Brain aneurysm treatment is almost always carried out on the NHS in specialist centres, often urgently after a bleed. Private treatment is uncommon; people sometimes seek a private second opinion about whether to treat or monitor an unruptured aneurysm.

What happens if my aneurysm bursts?

A burst aneurysm causes a sudden, severe headache and is a medical emergency — call 999. It is treated urgently to stop further bleeding, usually by coiling or clipping, followed by close monitoring and often rehabilitation.

Will I need medicines afterwards?

If a stent or flow diverter is used, you will usually need blood-thinning (antiplatelet) medicines for a period to stop clots forming on it. Many people also need good blood-pressure control. Your team will explain exactly what you need and for how long.

Could the aneurysm come back after coiling?

Coiled aneurysms can sometimes fill again over time and may need further treatment, which is why follow-up scans are usual. Clipping is very durable. Your team will arrange the right monitoring for your situation.

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How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: NHS — Brain aneurysm: treatment NHS (UCLH) — Coil embolisation in the treatment of cerebral aneurysms Brain & Spine Foundation — Brain aneurysm ISAT — long-term outcomes of clipping versus coiling (PMC) Procedural complications of coiling of ruptured aneurysms (PMC) GOV.UK / DVLA — Health conditions and driving DVLA — Assessing fitness to drive (medical guidance) DVA Northern Ireland — Telling DVA about a driver medical condition

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.