A TDAP flap refers to the Thoracodorsal Artery Perforator flap, which is based upon the soft tissue of the lateral upper back overlying the latissimus dorsi muscle. It is often used as a pedicled flap to fill small contour defects left in the breast after prior surgery or small resections of breast tissue. The TDAP is usually not a flap that can create a full breast mound.