Profile of the surgery performed
in the Unit
About acoustic neuromas
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What is an acoustic neuroma or vestibular schwannoma?
An acoustic neuroma is a benign tumour (NOT a cancer)
that grows on a branch of the acoustic nerve (called the eighth
cranial nerve). In most cases, the tumour grows on the vestibular
(balance) branch of the eighth nerve (see below). For this reason,
an acoustic neuroma is more correctly called a 'vestibular schwannoma'
because it arises from schwann cells (types of nerve sheath
cells) in the vestibular apparatus of the ear.
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What does the acoustic nerve do and where does it run?
The acoustic nerve has two functions: hearing and balance. The
nerve runs from the organs in the ear that control balance and
hearing to the brain through a tiny bony canal called the internal
auditory meatus. The facial nerve (called the seventh cranial
nerve) also runs through the internal auditory meatus. The facial
nerve controls the muscles of the face and contains some nerve
fibres that control taste and tear production, which is why
surgery in this area can affect these functions.
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What causes acoustic neuromas?
We don't know why some people develop acoustic neuromas,
but in many cases it arises spontaneously or from a genetic
alteration (mutation). We have no evidence that infections,
or other trauma to the head or ears cause the benign tumour
to start growing. If someone has had one, they are not more
likely to get another in the other ear, unless it is part of
a syndrome called neurofibromatosis type 2 (NF2), which is a
hereditary disease. Only 5% of acoustic neuromas are in people
who have NF2.
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How common are acoustic neuromas and who do they affect?
Acoustic neuromas affect one in every 100,000 of the population;
they affect women as often as men. Most acoustic neuromas are
detected between the ages of thirty to sixty years.
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How fast do acoustic neuromas grow?
These benign tumours usually grow very slowly, at a rate
of about 1 to 2 mm a year. This means it is usually safe to
plan surgery ahead of time. Sometimes, they do not grow for
many years or stop growing.
Symptoms and diagnosis of acoustic neuromas
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What symptoms do acoustic neuromas give?
The first symptoms of acoustic neuromas can be a loss of hearing
in one ear, tinnitus (or buzzing) in one ear or in the head
generally or general unsteadiness. Later symptoms include headaches,
facial numbness, a deterioration in sight and loss of co-ordination.
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Do acoustic neuromas affect both ears at the same time?
Acoustic neuromas usually affect only one ear. This means that
people usually only get symptoms on the affected side, and after
operations they only get complications on the same side.
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Where does the acoustic neuroma start growing?
Acoustic neuromas usually start growing in the nerves of balance
within the bony canal that houses the ear. When the tiny amount
of space in the ear is filled with the benign tumour, the tumour
then begins to grow along the nerve towards the brain. There
is little change in the symptoms experienced until the tumour
begins to push against the brainstem.
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How are acoustic neuromas usually detected?
Acoustic neuromas are usually detected by doctors following
a magnetic resonance imaging (MRI) scan; these can be arranged
for a patient by a general practitioner or hospital doctor.
Surgery for acoustic neuromas
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Why do acoustic neuromas need to be removed?
The area of the ear and brain in which the acoustic neuroma
grows is very small. Therefore, there is very little room for
the tumour to grow. Eventually, without treatment, the tumour
can press upon the brainstem and the nerves surrounding it.
This pressure can cause serious health problems such as headaches,
deterioration of sight, facial numbness and loss of co-ordination.
At surgery, the smaller the acoustic neuroma is, the easier
(and safer) it is to remove. Because the tumour grows so slowly,
this usually gives us a fairly generous time period to detect
it and plan surgery.
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What does the surgery entail?
Your surgeon will discuss the details of the surgery with you.
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Does surgery cure all acoustic neuromas?
Surgery cures almost all acoustic neuromas. The incidence of
tumours regrowing is very low: 0.5% (one in 200 patients).
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Will surgery for acoustic neuroma cure tinnitus in that
ear?
Some patients have tinnitus ('ringing in the ear') before surgery,
which is a symptom of acoustic neuromas. This symptom does not
always stop after surgery; approximately 40% of people will
be cured of the tinnitus, 47% will experience no change in symptoms
and 13% will experience worsening tinnitus.
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What are the side effects and risks of surgery?
You will need to have an operation on your leg at the same time
to provide tissue for the operation on your ear. It is likely
that you will lose any hearing in your affected ear - this will
be discussed with you before you decide to have the surgery
(see below). There is also a lesser risk of short/medium or
long-term weakness of the face (or inappropriate movement) on
the affected side, eye dryness or weeping and affected taste
(see below).
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Is it possible to save the hearing in my affected ear by
using a different type of surgery?
Most people who have acoustic neuroma have very poor or no hearing
before surgery. In a very small number of patients, it might
be possible to use a different surgical approach that can try
to save the hearing in the affected ear - but the chances of
saving the hearing are not high. This retrosigmoid approach,
is not performed through the mastoid bone but further back on
the head. However, your hearing tests must be good for this
to be considered. If the hearing is successfully preserved during
surgery, it is, however, rarely better than it was before surgery.
This type of surgery is not more risky than the other approach.
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Why will I have an operation on my leg too?
The brain is enclosed in a bag of fluid (cerebrospinal fluid,
CSF), which is opened during the surgery for acoustic neuromas
to enable the surgeons to access the neuroma. In order to seal
the bag and prevent the wound from leaking the CSF, during surgery
we take some tissue from your leg to patch the area. The tissue
is fat from the leg and the covering of the muscle (called fascia).
For this reason, after the surgery, you will have a wound the
outside part of the mid-thigh on your leg, which is closed with
stitches (sutures). An alternative to the leg is the abdomen
(tummy). Your surgeon will explain the details of the operation
to you.
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Where will I have scars?
We will need to shave part of your head and you will have an
inverted 'J' scar behind the ear (which will eventually be covered
with hair for most people). The scar on your upper leg will
be a straight line of approximately 10 to 15 cm in length. Both
of these scars will fade with time.
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Is it safe to decide NOT to have surgery?
Generally, if the tumour is larger than 10 mm, it will need
treatment - either by surgery or by stereotactic radiotherapy
('gamma knife'). If it is less than 10 mm in size, it is possible
to adopt a 'watch, wait and rescan policy'. Because the tumour
grows slowly, you and your surgeon have some time to decide
whether and when to have the surgery.
Side effects and complications of surgery
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Will I definitely lose my hearing in the affected ear?
Most people who have acoustic neuromas have poor or no hearing
in the affected ear. The commonly used approach for surgery
for acoustic neuromas involves destroying the hearing mechanism
in the affected ear, which means it is very unlikely that you
will have any hearing in the affected ear after the surgery.
If you have no hearing, therefore, it will not be helpful to
wear a hearing aid in this ear. Fortunately, after surgery,
many patients find that although they have lost hearing on the
affected side, the clarity of hearing with the unaffected ear
is improved because the distortion from the affected side has
been removed. There are also alternative forms of the surgery
that can preserve the hearing in a small proportion of patients
(see above).
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Why will the affected side of my face become weak after
surgery?
The nerve that controls the movement of part of one side of
the face (the facial nerve) runs through the same bony canal
as the acoustic nerve (see above). Usually, by the time of surgery,
the acoustic neuroma has grown large enough to stretch the facial
nerve over the tumour. During surgery, the facial nerve is treated
with great care, and its function is monitored throughout the
surgery. This tells us to what extent the nerve is working at
the end of the surgery. However, the nerve can sometimes become
bruised and swollen owing to the need to separate it from the
tumour. If this happens, the face on the affected side will
become weak at least in the short term. Many patients suffer
with a facial weakness on the affected side immediately after
the surgery - although, in most cases, the facial nerve is still
intact and should be functional in the longer term. As long
as the facial nerve remains in one piece at the end of surgery,
it will almost always recover to some degree (it can improve
for up to 18 months). However, we are unable to predict the
extent of the recovery of the facial movement in the early stages
after surgery (see below).
Treatment at Addenbrooke's
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What will happen at my first hospital appointment for treatment
of an acoustic neuroma?
A surgeon will ask you some questions (clinical history), examine
you, do some hearing and balance tests and then discuss things
with you in detail.
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How soon can surgery be arranged after my first hospital
appointment?
You will be sent a date for surgery after the appointment. There
might be several weeks delay because surgical scheduling is
done in 'batches' with all cases being discussed by the full
surgical team. The urgency of operation for each patient is
considered individually. The date given for surgery will depend
on the size of tumour and the symptoms it is causing. The waiting
time before surgery is generally around 2 to 4 months. No one
likes waiting for surgery, but because this type of tumour is
benign (not a cancer) and it grows very slowly, the wait should
not cause any additional medical problems. If you are worried
about the wait or your symptoms have changed, please return
to your general practitioner or contact Jean Hatfield the acoustic
neuroma nurse practitioner.
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Will I have another MRI scan before coming to hospital for
the surgery?
Acoustic neuromas grow very slowly, therefore, it is not
usually necessary to repeat a magnetic resonance imaging (MRI)
scan immediately before coming into hospital.
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What types of therapy will I have after surgery?
You will have some physiotherapy each day after surgery to help
improve your balance and help you walk again safely. This is
because the surgery affects the nerve controlling balance. You
might also be given some simple exercises to prevent the muscles
of the face from becoming too tight or too weak. The physiotherapist
will also give you some important exercises to continue with
at home, which will improve your balance and facial function.
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How long will I have to stay in hospital before and after
the surgery?
After surgery, you will be able to go home as soon as the doctors,
nurses and physiotherapists think you are ready, which is usually
about one week after surgery. It is important to get you moving
early on to avoid the side effects that patients can experience
if they stay immobile for extended periods.
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How can I leave hospital?
We will involve you in your plan for leaving hospital (the discharge
plan) so that you can ask a friend or relative to collect you
at a convenient time. If this is not possible, we might be able
to organise some hospital transport for you (further
information about hospital transport).
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What kind of follow up will I have after the surgery?
Your follow up after surgery will be at 3 months, one year and
finally two years when you will have a further MRI scan of your
head (postoperative scan). After you leave hospital, you will
be sent an outpatient appointment to review your progress after
surgery. The first appointment with the neurosurgeon in the
Unit is likely to be two months after the surgery and then about
six months after that. Around this time you might be discharged
from the surgical clinic. The neuro-otologist will see you in
their outpatient clinic around three months after your surgery,
then at one year and finally at two years. An MRI scan will
be performed at two years ensuring that your acoustic neuroma
has not re-grown. You will be discharged after two years; it
is extremely unlikely that the tumour will re-grow or that any
will have been left behind.
After surgery
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How will I feel after the operation?
There might or might not be weakness of the face or loss of
balance. It is quite common to feel dizzy and very tired immediately
after this type of surgery. Often people will have a headache
for two or three days immediately after the surgery. This is
because it is major surgery and also to your head.
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How will I know that I am ready to leave hospital after
surgery?
The medical staff will want to be sure that the wound in your
head and leg have healed, and that there is no leakage of cerebrospinal
fluid (CSF) from the head wound. The nurses will also want to
be sure that you will be able to manage at home with only minimal
assistance. The physiotherapists will want to be sure that your
balance has compensated enough to allow you to walk safely.
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Do I need to contact my GP after the surgery?
When you leave hospital, you will be given a hand-written letter
that summarises your stay at Addenbrooke's. Please deliver this
to your GP's surgery as soon as possible. A typed summary will
also be sent to your GP, which will inform them of any medications
that you have been prescribed and the details of your surgery.
You do not need to make an appointment to see your GP, unless
they have specifically asked you to do so or you have any problems
(eg eye problems, headaches, clear fluid leaking; see below).
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How long will I feel tired for, and what can I do about
it?
Towards the end of your stay at Addenbrooke's after surgery
for acoustic neuromas, the tiredness will have started to improve.
However, when you return home you might find that you again
become very tired. This is usually because there are more activities
to occupy yourself with at home. You might find it useful to
have short sleeps in the afternoon until your energy returns.
It is very important that you don't do too much when you get
home. A slow, and gradual increase in your activity level will
help you to recover, and will still avoid the side effects you
might experience because of immobility. If there is a particular
event or activity that you want to participate in, and you feel
able to, then do try. If you become tired, stop, rest and recuperate.
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Will I be able to drive after surgery?
There is no need to inform the Driving and Vehicle Licensing
Authority (DVLA in Swansea) that you have had surgery, unless
you are specifically instructed to do so by a member of the
medical team. The DVLA's general advice is that you do not return
to driving until 'fully recovered from the surgery'. The time
this takes varies enormously between patients, and depends on
your ability to perform an emergency stop, being able to glance
into your mirrors and being able to look right and left without
feeling nauseous and dizzy. When you feel able to do these confidently,
you should be able to return to driving safely. To begin with,
however, we recommend that you drive only for short distances
and gradually increase the distance.
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Can I travel by aeroplane after surgery?
It is best to avoid travelling by aeroplane after acoustic neuroma
surgery until at least three months after the surgery. This
is to prevent the patch that has been used after your surgery
from leaking CSF (see above) during changes in atmospheric pressure.
After three months, the patched area should be healed and flying
should not cause any problems.
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When can I go back to work or resume normal daily living?
When you can go back to work or resume your normal daily living
depends on the size of the tumour removed and your recovery.
We usually recommend that you convalesce and stay off work for
three months but this might be shorter or longer than you need.
It can take this long to build up your energy levels. Do not
be tempted to go back to work too early because you might become
very tired, very quickly. If you have a job that allows you
to resume work on a part-time basis, then do take this opportunity
and gradually build up to your usual hours. Only you will really
know when you feel able to go back to work, but a good rule
of thumb is around the time of your three-month appointment
in the neurotology clinic.
Things to look out for after leaving hospital
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If I have a headache after the operation, what should I
do?
It is common for patients to experience headaches immediately
after surgery because they have had major surgery to the head.
By the time you leave hospital, these headaches should have
started to at least resolve if not disappear completely. Some
people do suffer with nagging headaches after the surgery, which
can usually be relieved with simple pain killers (eg paracetamol).
If you have a persistent headache, which is not relieved by
simple pain killers, especially if you have one or more of the
following: (a) light hurts your eyes, (b) you have a stiff neck
(c) you also have nausea/vomiting, please contact your GP as
soon as possible.
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What should I do if I notice clear fluid coming from my
nose, ear or wound?
Cerebro-spinal fluid (CSF) is a clear fluid that surrounds the
brain and is prevented from leaking out by being enclosed in
a bag. During your surgery,we need to cut though this bag and
patch it afterwards with tissue from your leg. While you are
in hospital, the medical staff will check for leaks of CSF from
your nose, ear and your head wound. By the time you leave hospital,
it is unlikely that you will develop a leak of CSF. For the
first few days at home, do keep an eye out for clear fluid from
your nose, ear or wound and if you notice any please contact
your GP or the Unit nurse practitioner as soon as possible.
About problems arising from bruised or damaged facial nerves
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What will 'weakness of the face' mean to me?
Patients who have had surgery near their facial nerve experience
many differing degrees of facial weakness (also called palsy).
It is almost impossible for us to predict how much facial weakness
a particular patient will experience after surgery. For example
your mouth might droop on the affected side, your eye on that
side might not close properly (or at all), and your cheek on
that side might droop. However, you might not experience any
of these short to medium term effects. It is important to remember
that the surgery only affects the side of the face that has
been operated on - the other side has its own facial nerve supply
and should be unaffected.
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How will I know if I have weakness of the facial nerve?
The function of your face (and therefore the facial nerve) will
be assessed by the medical team on a regular basis after surgery.
This weakness can start to be experienced up to 15 days after
surgery, so you might only notice it after you have left hospital.
We will support you through this period as necessary.
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What are the other effects of a bruised or damaged facial
nerve?
Following surgery for acoustic neuromas, you might have one
or several of the following: a degree of facial weakness and
incomplete eye closure (see above). You might also experience
inappropriate facial movement such as spontaneous twitching
of one group of muscles. You might also have dryness or excess
tears in the eye because of the facial nerve weakness. You can
also experience an alteration of taste because the fibres of
the facial nerve, as they regrow, can do so down the nerve sheathes
of different nerves. These are because the facial nerve runs
very close to the acoustic neuroma. As you begin to make your
recovery from the surgery, these should slowly begin to improve.
The facial nerve can recover quite slowly, so please be patient.
We know that patients can continue to improve function for up
to about 18 months, and we will support you throughout this
time.
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If I experience symptoms in my eyes after surgery, how will
I be supported?
If you have a facial weakness after your surgery, you might
have difficulty in closing eye on your affected side or have
a dry or weeping eye on that side. Depending on the amount of
difficulty you experience, we might arrange for you to see an
eye specialist before you leave hospital. Even if you don't
see an eye specialist after your surgery, it is very important
that you take great care of the eye on the affected side. If
your eye does not close properly, it is more at risk of damage
from foreign objects and/or infection. It can also become sore
if enough tears are not being produced. If necessary, we will
prescribe eye drops and eye ointment for you to take home. Please
follow the instructions carefully (see below).
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If I am given eye drops, how should I use them?
Do follow any instructions you are given with the eye drops.
In general, eye drops should be used at regular intervals (every
15 minutes if the eye is particularly dry) to keep the eye moist
during the day and they should be used before retiring to bed.
If the eye stings when the eye drops are inserted, you might
be sensitive to the preservative used and you should obtain
some preservative-free drops from your general practitioner
(GP) or a chemist.
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If I am given eye ointment, how should I use it?
Do follow any instructions you are given with the eye ointment.
In general, eye ointment is used to lubricate a dry eye and
should be used regularly at night. It can be used during the
day but it might blur the vision. Put the ointment in after
the drops, otherwise the drops can wash the ointment out.
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If I am given an eye bubble, how should I use it?
An eye bubble is a clear 'bubble' that can be placed over
the eye to protect it if it is at particular risk. It should
be worn at night because you are unaware of foreign bodies coming
into contact with the eye when you are sleeping. Do not wear
it during the day because the warm, moist environment that is
produced under it can lead to eye infections.
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If my eyes are affected, what else should I do?
Your doctors will tell you to 'Think Blink' to remind you
to actively try to close your affected eye at least once an
hour. This will help the muscles around the eye recover and
also protect the eye. If the eye becomes red, sore or irritable
then seek early advice from your GP or an ophthalmologist -
this could be the start of an eye infection and might need to
be treated.
This information supplements the information given to you before
and after your surgery. Please do not hesitate to ask your medical
and nursing staff any questions you might have. Also on this website: |
