Comparisons of the postoperative rectus abdominis muscle thickness and the biomechanical properties of donor sites among different subtypes of muscle-sparing transverse rectus abdominis myocutaneous flaps (MS0, MS1, MS2, MS3): a rat model.

Abstract

The primary presumed advantages of the deep inferior epigastric perforator flap over the other muscle-sparing (MS) transverse rectus abdominis myocutaneous flaps are the improved functional rectus abdominis muscle outcomes and decreased abdominal contour morbidities. The purpose of this study was to verify this viewpoint objectively and quantitatively using an animal model. Six rats were used in the pilot study and 40 rats were equally divided into a control group and 4 experimental groups (MS0, MS1, MS2, and MS3) according to the amount of rectus abdominis muscles harvested. At 3 and 6 weeks, 4 rats in each group were killed, then, the percentage of residual rectus abdominis muscle thickness compared with the control side and the ultimate load at failure of the abdominal wall were recorded and compared. All of the flaps survived completely without complications. Regarding the percentage of residual rectus abdominis muscle thickness compared with the control side, the results suggested MS3 > MS2 ≈ MS1 > MS0; concerning the ultimate load at failure of the abdominal wall, the results showed MS3 ≈ MS2 > MS1 > MS0. (≈: P > 0.05; >: P < 0.05). According to the findings of this study, we advocate the use of the deep inferior epigastric perforator flap when possible, and the MS2-transverse rectus abdominis myocutaneous flap can serve as a backup when the perforator anatomy does not meet the flap safety criteria for preservation of rectus abdominis muscle function.