This involves making an incision a few centimetres long but the size is kept to a minimum. Once the sample is taken, the incision is closed with stitches. The scar from this technique will be bigger than from the needle biopsy, but it allows a bigger specimen to be collected, which may be necessary in some cases, and makes the need for a second biopsy less likely. The technique may take about half an hour, but produces a larger sample, and allows direct vision of the muscle giving a more certain result.
Both types have their advantages and disadvantages, and the preferred method partly relates to the reason for the biopsy. Where both options are possible, patients may be asked their preference of procedure.