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 that 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.

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 antiinflammatory 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 has 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 have to fast. 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 and the biopsy itself only takes a few minutes. 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 sutures and Steristrips® (strong sticky plasters), which are applied over the sutures, and 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 of infection around the surgical site. This risk is minimal, as the procedure takes place in theatre. Your child might complain about some pain when they wake up after the procedure. Paracetamol or other pain medication appropriate for your child can be offered.

What happens after the biopsy?

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 it comfortable.

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 be 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.
  • „„The wound is closed with stitches, usually the dissolvable type. You should make an appointment with the practice nurse at your family doctor (GP) surgery to check the wound site in three to five days time.
  • „„You should keep the biopsy site clean and dry until the stitches are removed or the GP or practice nurse has checked the site. You may cover the site with cling film when showering or give your child a sponge bath until it is healed. 
  • „„Although not seen very often, your child may be uncomfortable walking or moving his or her leg and may need some support initially. For this reason, we usually suggest taking the day off school after the procedure. He or she 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 him or her 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
Compiled by: 
Kingfisher Ward in collaboration with the Child and Family Information Group.
Last review date: 
April 2014


Please note this is a generic GOSH information sheet. If you have specific questions about how this relates to your child, please ask your doctor. Please note this information may not necessarily reflect treatment at other hospitals.