If there is not enough tissue in the tummy area (abdomen) to perform the procedure, a similar technique can be used to take tissue from the upper buttock without damaging the muscle. Micro-surgery is then performed to reconnect the blood vessels of the flap to the existing blood vessels at the side of the sternum. A new breast is constructed from the transposed flap. Known as a free Superior Gluteal Artery Perforator flap, this procedure leaves a diagonal scar on the buttock.