What is the role
of surgery?
Surgery is offered to patients with a cSDH causing symptoms. It may also be offered to those with cSDH unlikely to resolve without surgery and felt to be very likely to cause symptoms in the future (this is often judged by how big the cSDH is in relation to the brain). Surgery is generally well tolerated; 8 in 10 people will recover to their baseline before the cSDH caused symptoms.
Surgery aims to wash clear the cSDH and allow the brain to re-expand. This can be readily achieved as a cSDH generally has the consistency of water. In the United Kingdom the commonest type of surgery is called ‘burr hole’ drainage. One or two holes are drilled through the skull to the subdural space, allowing the cSDH liquid to drain out. To help prevent the fluid returning, a soft plastic tube is left behind and connected to a bag at the bedside. This is taken out on the ward two days later.
What are the
risks of surgery?
However, there are some risks, including leading to an infection, or less commonly a stroke or seizures. Further in approximately 1 in 10 cases, the cSDH can reform and a repeat surgery may be required. Up to 2 in 10 people will therefore suffer a setback. The risk of death from the surgery directly is less than 1 in 100.
Do I need an anaesthetic?
Surgery can be done under general anaesthetic (where the patient is completely asleep) or using local anaesthetic to prevent discomfort, sometimes with a medicine to make the patient slightly sleepy but still able to talk with staff (sedation). Prior to the operation you will be reviewed by an anaesthetist who will help advise on an appropriate anaesthetic choice.
What are the
risks of a general anaesthetic?
Text to be provided
What can I expect from surgery?
Surgery is performed by Neurosurgeons. Neurosurgeons are only found in certain large hospitals. Most patients must therefore be transferred to such a hospital for surgery. This may take a few days depending on capacity and the severity of symptoms.
Once in the Neurosurgical centre, a Neurosurgeon will reconfirm that surgery could be of benefit. This involves checking the symptoms are related to the cSDH and if there are any specific reasons that might make surgery riskier and/or less likely to benefit. This information is then used to come to a shared decision with the patient.
Very often people with a cSDH requiring surgery will lose their ability to think for themselves and make their own decision. In these circumstances, where possible, relatives are contacted to help reach a decision that is in the best interests of the patient.
Once a decision has been made for surgery, various checks will take place to ensure the best conditions to undergo surgery. This might include having blood tests, a heart tracing (ECG) or receiving certain medication to improve the ability of the blood to clot. These procedures are overseen by both the Neurosurgeons and the Anaesthetist, a doctor who puts people to sleep during an operation.
In the UK, cSDH surgery is generally done asleep (General Anaesthetic, with a machine controlling breathing). The alternative is for the procedure to be performed under local anaesthetic (awake). This is sometimes preferred if the risks of a general anaesthetic are felt to be very high. It is worth noting that in many countries, the procedure is mainly performed with a local anaesthetic.
While these preparations are taking place, a time for surgery will be sought. Once surgery has been agreed, the aim is to offer it as soon as safely possible. In practice this can take a few days. This is mainly because other more pressing emergencies that Neurosurgeons also help treat may need to take priority. Such emergencies can arrive at any time, and this means that it may take several days to undergo surgery for cSDH once arriving in the Neurosurgical centre. As patients are ideally starved of food for 6 hours, and of water for 2 hours, prior to surgery these emergencies can lead to postponed cSDH operations and prolonged periods of starving. This is a common source of frustration. If you become aware of any worsening of symptoms these should be raised with the neurosurgical team.
The surgery is performed in an operating theatre and may require the surgeon to shave some hair on the side where the cSDH is present. This helps the surgeon see and reduces the risk of infection.
What happens
after surgery?
Once the surgery has been performed, the patient will return to the ward. Generally, there will be a plastic drain coming out of the wound. This helps to clear all of the cSDH and is normally removed after two days.
Following this it might be necessary to have input from rehabilitation professionals such as physiotherapists, who will start to help support recovery and allow safe discharge home. Some patients respond very quickly and are able to go home once the drain is removed. However, most patients take 1 to 2 weeks, with the average length of stay in hospital 10 days.
If the Neurosurgical centre is not the local hospital, this recovery will include transfer back to the original hospital. This can take a few days to occur, but is necessary as the local hospital is able to organise any home assistance or adaptations to allow safe discharge from hospital.
What are the alternatives?
The main alternative to surgery is to watch and wait, recognising that many cSDH will disappear on their own. This may include stopping medication, such as those that thin the blood, which might increase the risk of the cSDH growing. However this can increase the risk of other problems, such as blood clots. Whether or not such medication should be stopped is unclear, and is a conversation to have with your treating doctor. It is currently not possible to predict cases where a cSDH will disappear. Many believe large cSDH or those shown on imaging to be growing are less likely to disappear.
In some centres, a new technique called ‘middle meningeal artery emobilisation’ is being used, as there is some suggestion that it can help cSDH disappear. A clear understanding of how this treatment works, including its risks and benefits, is still missing and therefore most hospitals do not currently offer it.
Whilst it remains an area of research, there are currently no specific medicines to help a cSDH disappear. Historically, steroids were used but recent high-quality studies have shown they cause more harm than good.
Should I have surgery?
This decision must always be tailored to the individual circumstances.
Broadly, surgery is offered to all symptomatic cSDH and occasionally those cSDH likely to expand and cause symptoms. This is because overall, the majority benefit, few have setbacks, and without it, symptoms are not expected to resolve.
However, we do know that approximately 15 in every 100 cSDH patients treated with surgery will pass away within 1 year of having surgery. This is rarely attributed to the surgery itself, but instead reflects that cSDH often affect people in the later stages of their life who may have other health problems.
Establishing whether surgery is the right course of action must therefore be tailored to the individual circumstances.