Excision of Acoustic Neuroma

Indications for surgery: Growth of a small tumour under observation, or larger tumours causing compression or symptoms.

Important considerations before surgery: Many small tumours will not grow over time and so can safely be ‘watched’…very carefully. If the tumour is small and not growing then no treatment may be suitable with a ‘watch..wait.. rescan plan scheduled. Small growing tumours are also suitable for radiosurgery evaluation. There are complex considerations when deciding in a small growing tumour which is the best treatment for each patient. I will discuss the options with you and if needed refer you to a radiation doctor with expertise in treatment of these tumours.

Evidence for surgery: For larger tumours there are usually no treatment options other then surgery. This is the only method of removing the tumour and taking away the compression. This is complex surgery which should only be performed by neurosurgeons with subspecialty training in removal of this tumour type.

Benefits of surgery: Removal of the tumour to stop growth and remove compression on the brainstem, which is one of the most sensitive and critical parts of the brain.

Risks of surgery: This is complex difficult surgery with serious, real risks from the surgery. Complications are minimised by treating this type of tumour in experienced specialist teams. Serious risks include death, stroke and major neurological disability. Thankfully performing surgery in expert teams has reduced the mortality from this surgery to ~2% though the risks are higher in large tumours. Most patients will lose hearing on the side where the tumour occurs following the surgery though ‘hearing preservation’ surgery may be attempted. The tumour wraps around the ‘facial nerve’, which has the function of innervating the muscles that move the face. After the surgery patients often experience weakness of these muscles. If the nerve is preserved and is working with electrical stimulation during the surgery, post operative weakness of the face is likely to be temporary, often improving or normalising over the year following the surgery. If weakness does not improve there are many surgical techniques to improve facial function and return function. Other nerve problems following this surgery include swallowing and speech disturbance which can be serious and disabling, facial numbness and double vision. Other more general complications include CSF leakage, infection, bleeding, wound pain, neck pain and ongoing headaches. All patients have a risk of medical and anaesthetic complications following surgery. Patients should note that tinnitus does not usually improve following the surgery.

Brief description of the surgery: Patients are given general anaesthesia. Hair behind the ear on the affected side is shaved and an incision is made behind the ear. Depending on the exact type of operation you are having bone will be either removed in front or behind a blood vessel called the sigmoid sinus. Removal of the bone allows access to the brain and the tumour. Brain and spine fluid is removed and the brain relaxed allowing the tumour to be seen. The tumour is then carefully and meticulously separated from the nerves, blood vessels cerebellum and brainstem surrounding the tumour. All of this surgery is performed using the operating microscope under great magnification. The tumour is removed from the inside out allowing the walls of the tumour to be ‘rolled in’ on themselves and the structures surrounding the tumour to be seen and protected. The balance nerves, which the tumour arises from, are divided but the facial nerve and sometimes the hearing nerve are preserved. The plan is typically to remove the whole tumour, which is usually possible. In cases where the tumour is very ‘stuck’ to nerves, arteries or the brainstem, a small amount of tumour may be left so as to preserve function. Once the tumour is removed the wound is closed. The wound closure may require removing some fat and tissue from the abdomen or the thigh, which requires another incision.

After the surgery (which usually takes all day) patients are monitored very closely in a high dependency environment with close attention from specialist nurses and doctors. After removal of this tumour the balance nerves have to re-adjust and patients often feel very sick and disorientated. This gets better over a few days. Patients are slowly mobilised once they start to feel more orientated. Specialist physiotherapists give the patient balance training exercises. This is a major operation and recovery is slow with patients usually spending 5-7 days in the hospital after surgery. Full recovery takes months but patients usually start feeling a lot less tired and stronger after about 6 weeks.

Dressings stay intact after the surgery for 10 days during which time the dressings must stay clean and dry. If the wound becomes wet or the dressings soaked they will need to be changed. Patients should see their GP or practice nurse after 10 days for a wound review. Any concerns should prompt you to contact me or my team at the hospital.

Driving and return to work should not take place during the 6 weeks following the surgery. I will review you after 6 weeks in the clinic and make a plan with you about returning to work and driving.