Patient education: Muscle biopsy (The Basics)

What is a muscle biopsy? — 

This is a procedure to check a small sample of a muscle. Doctors often use the muscle in the front of the thigh, upper arm, or shoulder for a muscle biopsy.

Some common reasons to have a muscle biopsy include:

●To learn about causes of muscle weakness and muscle disease

●To see if a mass on the muscle is caused by cancer

●To test for diseases that affect blood vessels or "connective tissues" (these are tissues that support the organs inside the body)

●To test for a muscle infection

●To help plan treatment for a medical problem

How do I prepare for a muscle biopsy? — 

The doctor or nurse will tell you if you need to do anything special to prepare.

Before the procedure, your doctor will do an exam. They might send you to get tests, like:

●An ultrasound, MRI, or other imaging test – These create pictures of the inside of the body.

●Nerve conduction studies – This records the electrical activity of nerves at rest and when stimulated.

●Electromyography, or "EMG" – This looks at the electrical activity of a muscle at rest and when it contracts.

Your doctor will also ask about your "health history." This involves asking about any health problems you have or had in the past, past surgeries, and any medicines you take. Tell them about:

●Any medicines you are taking – This includes prescription and "over-the-counter" medicines, plus any herbal supplements. It helps to write down and bring a list of your medicines, or bring a bag with all your medicines with you.

●Any allergies you have

●Any bleeding problems you have – Certain medicines, including some herbs and supplements, can increase the risk of bleeding. Some health conditions also increase this risk.

You will also get information about:

●Eating and drinking before the procedure – You might need to "fast" before the biopsy. This means not eating or drinking anything for a period of time. Or you might be allowed to have liquids until a short time before the procedure. Whether you need to fast, and for how long, depends on the type of biopsy.

●What help you will need when you go home – For example, you might need someone else to bring you home if you will get sedative medicines for the procedure.

Ask the doctor or nurse if you have questions or if there is anything you do not understand.

What happens during a muscle biopsy? — 

Depending on what the doctor is looking for, biopsies are done in different ways. Your doctor will recommend which type of biopsy to have, and where to have it, based on your health and medical problems.

When it is time for the procedure:

●You might get an "IV," which is a thin tube that goes into a vein. This can be used to give you fluids and medicines.

●You will get anesthesia medicines. This is to make sure you do not feel pain during the procedure. You might also get "sedative" medicines to help you relax.

●The main types of muscle biopsies are:

•Needle biopsy (also called percutaneous biopsy) – This might also be called a "fine-needle biopsy" or "core needle biopsy," depending on the size and type of needle used. The doctor will clean and numb your skin over the muscle. They might use an ultrasound or other imaging test to help them see where to place the needle. Then, they will use the needle to remove a small sample of your muscle. They might take more than 1 sample. When finished, they will remove the needle.

•Surgical biopsy (also called open biopsy) – This is usually done in an operating room, after you get sedation or general anesthesia. General anesthesia makes you unconscious so you can't feel, see, or hear anything during the procedure. The doctor will make a cut ("incision") over your muscle and take a small sample of tissue.

●The doctor will hold pressure or use stitches, skin glue, or medical tape to close any incisions and stop any bleeding. If needed, they will cover the area with clean bandages.

●The biopsy will be sent to the lab for testing.

●Most muscle biopsies take about 30 minutes to an hour.

What happens after a muscle biopsy? — 

If you had anesthesia, the staff will watch you closely as it wears off. Most people can go home the same day.

You will likely get the results of your biopsy in about a week. Your doctor will talk to you about what the results mean and what will happen next. If the results are not clear, your doctor will schedule another biopsy or procedure to get more information.

What are the risks of a muscle biopsy? — 

Your doctor will talk to you about all the possible risks, and answer your questions. Possible risks include:

●Pain at the biopsy site

●Bleeding or bruising

●Infection

●Injury to nearby organs or tissues

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