Changes in the local morphology of the rectus abdominis muscle following the DIEP flap: an ultrasonographic study.

This study was undertaken to assess the changes in the local morphology of the rectus abdominis muscle following intramuscular dissection of the deep inferior epigastric artery perforators after harvesting of the deep inferior epigastric perforator (DIEP) flap. While the DIEP provides the well-known advantage of use of the lower abdominal tissue with preservation of the integrity of the abdominal wall musculature, postoperative problems such as abdominal asymmetry, bulges and reduced flexion capacity have been found. These changes may be due to rectus abdominis muscle damage from ischemia or denervation. We used ultrasonography to assess the changes in rectus abdominis muscle thickness and contractility, preoperatively, 1-month and 1-year postoperatively. The study group consisted of 17 rectus abdominis muscles in 14 patients subjected to intramuscular dissection of perforators. The control group consisted of 11 intact rectus abdominis muscles in 11 patients who had undergone unilateral DIEP flap elevation, the dissected muscles being part of the study group. We found that the resting muscle thickness in the study group was, significantly increased at 1-month postoperatively, resolving by 1-year follow-up. As these changes were not seen in the control group, the increased muscle thickness is attributed to postoperative oedema that resolves with time. All muscles in the study and control groups retained contractility showing no evidence of muscle denervation. Our date demonstrates that intramuscular dissection of perforator vessels in the DIEP flap leads to minimal changes in the local morphology and contractility of the rectus abdominis muscle.