Cutaneous viability in a rat pedicled TRAM flap model.

Abstract

The transverse rectus abdominis musculocutaneous (TRAM) flap is widely used in breast reconstruction. However, morbidity with its pedicled form has resulted in a high incidence of complications. The authors conducted a study of the pedicled TRAM flap procedure in 35 female Wistar rats based on the left deep inferior epigastric vessel, which was nondominant. In all the rats, the flap was divided into four areas: area 1, the skin on the left rectus abdominis muscle pedicle; area 2, the skin contralateral to the midline, opposite of the left rectus abdominis muscle pedicle; and areas 3 and 4, the skin lateral to areas 1 and 2, respectively. The occurrence, percentage, and distribution of necrosis on the TRAM flap surface were determined. Necrosis was observed at four statistically distinct and significant levels, distributed in the four different areas as follows: area 1, 9 percent; area 2, 37 percent; area 3, 74 percent; and area 4, 100 percent (p < 0.001). The median proportion of necrosed flap surface was 15 percent (range, 2 to 42 percent). The determination of necrosis allowed us to identify three distinct levels of necrosis: area 4 with the highest scores, area 3 with intermediate scores, and areas 1 and 2 with the lowest scores (p < 0.001). Areas 1 and 2 of the TRAM flap surface had less incidence of necrosis, contrary to the lateral areas 3 and 4, in which cutaneous necrosis was found to be more significant.