Comparison of Abdominal Hernias in Superiorly- vs. Inferiorly-Based Pedicled Rectus Abdominis Flaps

The rectus abdominis muscle is a widely utilized flap for reconstructive surgeries. As a pedicle flap, it can be based either on the superior or the inferior epigastric vessels. The authors carried out a retrospective review of patients who underwent breast reconstruction with superiorly-based transverse rectus abdominis myocutaneous flaps and those who underwent proximal thigh reconstruction after sarcoma resection with inferiorly-based pedicled rectus abdominis myocutaneous or muscle-only flaps to determine the incidence of abdominal hernias and/or bulge formation with respect to which vessel was used.

Fifty-five patients were identified in the period between February 1998 and May 2005 (12 males, 43 females, mean age: 51.1 years). Thirty patients (F = 35) underwent superiorly-based pedicle TRAM breast reconstruction, and 20 patients (M = 12, F = 8) underwent proximal thigh reconstruction with inferiorly-based rectus abdominis after sarcoma resection. Marlex mesh was placed at the time of initial surgery in 2 patients with the TRAM reconstruction. No Marlex was used in the inferior pedicle group at the time of initial flap harvest. Thirty patients in the TRAM group had anterior rectus sheath plication at the time of closure. None of the inferiorly-based group underwent plication.

There was a significant difference (p = 0.0054) in hernia formation between the superior vs. inferior pedicle group. In the superior pedicle group, there were no hernias and 3 abdominal bulges. These 3 underwent further corrective surgery. In the inferior pedicle group, there were 4 hernias. All hernias were on the right. Two of the four had postoperative external radiation to the lower abdominal/superior thigh and one had immediate postoperative brachytherapy radiation. Three patients have had hernia repairs with either Marlex mesh or Alloderm. Two have had hernia recurrences after the repair (Marlex = 1, Alloderm = 1). There was no other correlation noted between hernia or bulge formation and age, sex, anterior rectus sheath plication, or mesh reconstruction.

The incidence of hernia formation is significantly higher when the pedicle rectus abdominis flap is based on the inferior epigastric vessels. Postoperative radiation was a factor in the development of hernia formation, and only the right side was involved. Due to the high rate of hernia formation in the inferiorly-based rectus abdominis flap, preemptive lower abdominal wall reinforcement may be indicated at the time of flap harvest.