This page explains about an open muscle biopsy and what to expect when your child comes to Great Ormond Street Hospital (GOSH) to have this procedure.
What is an open muscle biopsy?
An open muscle biopsy is a short procedure to remove a small piece of muscle tissue through an incision (cut) in your child’s thigh. The sample of tissue can then be examined under a microscope and tested chemically in the laboratories.
Why does my child need this procedure?
An open muscle biopsy is usually suggested when a child has a muscle abnormality of some kind, which might show up as unusually tense or floppy muscles and/or there is suspicion of important energy producing structures called mitochondria are not working properly.
The doctors can tell a certain amount by examining your child’s blood but there are some diseases that can only be diagnosed by looking at a sample of muscle. The reason for your child’s biopsy will be discussed with you fully by your child’s doctors.
Which muscle is biopsied?
We normally biopsy muscles in the nondominant thigh, that is, the leg your child tends not to use when kicking a ball.
What happens before the biopsy?
If your child is taking medicines on a regular basis, usually, he or she can continue to take them. Exceptions are ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs), which need to be stopped three days before the muscle biopsy is due to take place.
Muscle biopsies are usually done as a day case, that is, your child will come to the ward on the morning of the procedure and go home again that evening, unless he or she needs any further investigations or treatment, and/or the admitting doctor had decided otherwise.
The doctors will explain the procedure you in detail and they will ask you to give permission for the biopsy by signing a consent form. This will either already have been discussed before your child is admitted, or when your child’s doctors see you when you arrive on the ward. If your child has any medical problems, including allergies, please tell the doctors.
An anaesthetist will also see you to discuss your child’s anaesthetic. Your child will need to have a general anaesthetic for the procedure. This means that he or she will not be able to have any food or milk for six hours before the procedure, although your child can have clear fluids up to four hours beforehand. Some children are at risk of low blood sugar levels when they do not eat or drink, so they will be given a glucose solution through a ‘drip’ (intravenously).
What does the biopsy involve?
The procedure will be done in theatre under a general anaesthetic. The operation takes around 45 minutes, but there is additional time spent in transporting your child to the operating theatre, waiting and in preparation.
While your child is under anaesthetic, the doctor will make a small incision in your child’s thigh and remove a tiny sample of muscle tissue. This will then be sent to the laboratories for detailed examination.
The incision site will be closed with stiches. Selfdissolving stitches are used beneath the skin, and non-dissolving stitches in the skin. A Steristrip® (strong sticky plaster), is then applied. You should let us know if your child is allergic to any types of plaster. The wound is then covered with a dressing. At the end of the procedure, local anaesthetic will be used to numb the area so it is not painful for the first few hours.
Are there any risks involved?
Every anaesthetic carries a risk of complications but this is very small. Your child’s anaesthetist is an experienced doctor who is trained to deal with any complications. Sometimes after a general anaesthetic, a child may feel sick and could actually vomit. Your child may also complain of a headache, sore throat and feeling dizzy and may be upset. These side effects are usually short lived.
The amount of muscle biopsy needed for the investigations is small and therefore will not raise any problems using that muscle after surgery. There might be some bleeding straight after the procedure, but this will stop when pressure is applied to the site. There is a certain risk for an infection around the surgical site. This risk is minimal, as the procedure takes place in theatre.
Unfortunately there is always the possibility that muscle may not be obtained or the muscle biopsy is unsatisfactory, for example, due to excessive disease or technical problems. Sometimes a further biopsy may be necessary. If this is apparent at the time of the operation, another muscle may be biopsied at that time, or it may be necessary to return on another occasion.
Your child might complain about some pain after it wakes up post surgery. Paracetamol or other pain medication appropriate for your child can be offered.
What happens after the biopsy?
Patients who have the biopsy are usually able to go home later the same day after a period of observation. Your child will be able to recover from the biopsy on the ward and may be sleepy for a few hours as the anaesthetic wears off. Your child’s blood pressure, pulse and breathing rate will be monitored frequently as your child recovers.
The local anaesthetic given during the procedure will start to wear off a few hours later but we will give your child pain medicines to keep them comfortable. After the biopsy your child should rest their leg for the first day if possible, and keep the wound dry for two days.
The wound will gradually heal. Sports and excessive exertion should be avoided for at least two weeks. The skin stitches should be removed 10 days after the operation at your local surgery.
What happens to the muscle biopsy?
The muscle biopsy is processed and looked at under a microscope. Different tests are performed depending on the suspected diagnosis. The processing may take at least one week, and full analysis leading to a full report usually takes four to six weeks, or longer in more complex cases.
The result is sent to the referring doctor, who will then explain the findings to you. Any sample remaining after this analysis is stored, in case further analysis or re-analysis is required in the future. The remaining muscle may also be used in research into diseases of muscle, and development of new techniques.
When your child goes home
- The biopsy site may feel uncomfortable for a day or two afterwards. Your child might need paracetamol or ibuprofen (unless asthmatic) regularly, given according to the instructions on the bottle. Before you go home, the doctor will advise you about re-starting your child’s regular medicines.
- Your child will only been discharged when we feel it is safe. Do not worry if your child is sleepier than usual over the next 24 hours. This is due to the anaesthetic, which remains within your child’s body for a little while following the biopsy. However, if your child is unduly sleepy or difficult to rouse, make sure that he or she is in a safe position on his or her side and ring your family doctor (GP).
- Due to the anaesthetic your child may seem to have unusual mood changes, which make him or her cross and irritable. This is temporary.
- Some children feel sick and vomit following an anaesthetic. If this is the case, do not give your child anything else to eat until he or she is able to keep a drink down.
Although not seen very often, your child may be uncomfortable walking or moving their leg and may need some support initially. For this reason, we usually suggest taking the day off school after the procedure.
They should not take part in any contact sports or strenuous activity like PE or swimming until the stitches dissolve or are removed and the wound has properly healed, usually within two weeks of the biopsy. If your child feels wobbly when putting weight on the affected leg, support them on that side. This will improve in the days following the procedure.
You should call the ward or your family doctor (GP):
- If the biopsy site is still painful more than three days after the biopsy was taken and/or pain relief does not work
- If the biopsy site is red or ‘angry’ looking
- If there is any oozing from the biopsy site
- If your child develops a high temperature
- If your child is not eating or drinking
Last reviewed by Great Ormond Street Hospital: October 2012
Ref: 2012F0340 October 2012
Compiled by the Neurology department and Kingfisher Ward in collaboration with the Child and Family Information Group.
This information does not constitute health or medical advice and will not necessarily reflect treatment at other hospitals. If you have any questions, please ask your doctor. No liability can be taken as a result of using this information.