Muscle-Sparing TRAM Flap Does Not Protect Breast Reconstruction from Postmastectomy Radiation Damage Compared with the DIEP Flap

Abstract

Irradiation to free flaps following immediate breast reconstruction has been shown to compromise outcomes. The authors hypothesized that irradiated muscle-sparing free transverse rectus abdominis musculocutaneous (TRAM) flaps experience less fat necrosis than irradiated deep inferior epigastric perforator (DIEP) flaps. The authors performed a retrospective study of all consecutive patients undergoing immediate, autologous, abdomen-based free flap breast reconstruction with muscle-sparing free TRAM or DIEP flaps over a 10-year period at their institution. Irradiated flaps (external-beam radiation therapy) after immediate breast reconstruction were compared with nonirradiated flaps. Logistic regression analysis identified potential associations between patient, tumor, and reconstructive characteristics and surgical outcomes. The analysis included 625 flaps: 40 (6.4 percent) irradiated versus 585 (93.6 percent) nonirradiated. Mean follow-up for the irradiated and nonirradiated flaps was 60.0 and 48.5 months, respectively (p = 0.02). Overall complication rates were similar for both the irradiated and nonirradiated flaps. Irradiated flaps (i.e., both DIEP and muscle-sparing free TRAM flaps) developed fat necrosis at a significantly higher rate (22.5 percent) than the nonirradiated flaps (9.2 percent; p = 0.009). There were no differences in fat necrosis rates between the DIEP and muscle-sparing free TRAM flaps in both the irradiated and nonirradiated groups. Both DIEP and muscle-sparing free TRAM flap reconstructions had much higher rates of fat necrosis when irradiated. Contrary to our hypothesis, the authors found that immediate breast reconstruction with a muscle-sparing free TRAM flap does not result in a lower rate of fat necrosis than reconstruction with a DIEP flap. Therapeutic, III.