Fig. 1

The flap could be harvested using one of the following surgical approaches (based on the desired design): A Design Type A: The vascular pedicle of the skin paddles through the muscle segment, and the muscle segment is nourished by the descending branch of the TDA. No time-consuming intramuscular dissection is required in this type of design. Therefore, this type design was the ability to shorten operative time for dissection of the flap and reduce donor-site morbidity. B Design Type B: the muscle segment is associated with one independent vessels branch from the source vessel that could be rotated up to 180°. It has longer vascular pedicle between the paddles and provides a greater degree of spatial freedom to avoid the pedicle kinking and twisting, but time-consuming intramuscular dissection is needed and higher donor site morbidity was unavoidable. C Design Type C: multiple perforator vessels were dissected to nourish the large skin paddle whose area exceeds the maximum size of one perforasome. The muscle segment is located on a side branch of one skin paddle or a separate branch from one of skin flap, the vascular pedicle of this skin paddle does not require intramuscular dissection. The other perforator vessels also have enough length of vascular pedicles to be freely three-dimensionally inset into the defect