The TRAM flap can be transferred in two ways:
- The pedicled TRAM flap: The donor tissue is kept attached to the underlying rectus abdominis muscle. The muscle is divided at its lower end and rotated through a subcutaneous tunnel onto the chest wall. The origin of the muscle stays connected to the edge of the rib cage and therefore the blood supply to the tissue always remains intact.
- The free TRAM flap: In this procedure only part of the rectus abdominis muscle is sacrificed but its blood supply is completely disconnected. The deep inferior epigastric vessels are divided in the groin and then microsurgically reconnected to similar vessels in the chest wall or in the arm pit. It takes about 60 minutes to re-establish the blood supply.