While very reliable, surgeons and patients alike became concerned about the potential problems with the abdominal donor site in terms of bulging or hernias. It became clear that taking a smaller portion of the muscle still retained enough blood vessels to supply the overlying skin but at the same time was less destructive to the muscles in the tummy wall.
Today, we now know that the majority of abdominal flaps can be taken using just the skin, fat and the blood vessels supplying them as the DIEP flap, leaving the muscle behind or perhaps taking just a few fibres around the vessels (pedicle). However, in a small number of ladies it is not safe to do this and then a surgeon may need to harvest a MS TRAM flap in order to safe guard the new breast reconstruction. Reasons for this include immediate reconstructions in smokers or after chemotherapy when the dissection can be more difficult. Also the natural variation between patients means that while some have small numbers of large vessels supplying their abdominal skin (ideal for DIEP flap) others have very many small blood vessels which are impossible to tease out separately and are better taken as group with a square of muscle (safer to use the MS-TRAM). The small patch of muscle taken is repaired using a square of prolene mesh typically.
Please go through the information below in your own time to help your understanding of the options available.