The procedure will take place on the Neurological Investigation Unit which is located on Ward 11 at the Royal Victoria Infirmary.
The muscle biopsy procedure takes around thirty minutes. In total about a 1cm cube sample is removed from the middle of the muscle. There are several techniques that can be used. The appropriate one depends on the specific tests required.
This is performed in theatre. A 4 cm cut is made through the skin, exposing the muscle underneath and the wound is closed with stitches.
Conchotome or needle biopsy
These are performed on the ward. A specially designed instrument is passed through a 1cm cut in the skin into the muscle. To obtain a piece of muscle, the conchotome uses small jaws on the end and the needle uses a small window into which the muscle is drawn by suction and then shaved off. Adhesive strips rather than stitches close the wound.
Will it hurt?
Local anaesthetic is injected to numb the skin and the outer surface of the muscle. The muscle is not injected as this would disrupt its structure, and so mild discomfort may be felt when the muscle is cut.
Most diseases affect all muscles, even though not all may appear involved. The quadriceps muscle on the outside of the thigh is the most commonly sampled. It is a large, easily accessible muscle with no major nerves or blood vessels.
This is a simple procedure with a low risk of complications. The amount of muscle removed is very small and so this does not cause any weakness. Often a small bruise might be mildly uncomfortable for a few days. In around one in a hundred cases this might take a few weeks to settle. It is possible that permanent weakness, infection or a patch of numbness might occur but these are rare.
Check your medication!
To reduce the risk of bleeding, it is vital that you inform us of any drugs that could affect blood clotting. These include anti-flammatory tablets (such as indomethacin, ibuprofen, voltarol), anti-platelet drugs (such as aspirin, dipyridamole or clopidogrel) and anti-thrombotic drugs such as warfarin or heparin. These may need to be stopped up to two weeks prior to the biopsy. If this has not been done then the biopsy may be cancelled.
Please contact us if you are concerned regarding your medication and a risk of bleeding or indeed any other aspect of the procedure at either 0191 282 4443 or 0191 282 5011 from 8.00am until 6.00pm, Monday to Friday.