Purpose: Attempts to limit the impact of autogenous breast reconstruction on the abdominal wall have led to the use of the muscle sparing free TRAM, the DIEP and more recently, the SIEA flap. These three procedures, at least in theory, exist along a continuum that trades off reliability and donor site morbidity. The free TRAM has been consistently the most reliable flap with the lowest flap related complications, however the incidence of abdominal hernia and bulge have caused practitioners to turn to the DIEP. Theoretically, this flap has a lower incidence of abdominal wall complications, but may have a higher rate of flap related complications including fat necrosis and flap loss. At the other end of the spectrum, is the superficial inferior epigastric artery flap, which theoretically has a hernia rate of zero, but appears to have a higher rate of flap related complications than its deep pedicle counterparts.

The purpose of this study is to compare these three methods across a spectrum of clinical outcomes to determine if risks of flap complications are outweighed by benefits in abdominal wall function.

Methods: The authors retrospectively reviewed 569 consecutive free TRAMs, 50 consecutive DIEPs and 72 consecutive SIEAs. Outcomes measured included abdominal hernia, fat necrosis, partial and total flap loss, vessel thrombosis, hematoma and seroma, mastectomy flap loss and wound infection. Statistical Analysis included the use of Chi-Squared Analysis and Fisher's Exact test for non-parameteric, dichotomous outcome variables.

Results: There was no difference in age, past medical history, length of follow-up or recipient vessels among groups. In the SIEA and DIEP groups, there were higher percentages of obese patients (p = 0.0001), bilateral cases (p = 0.0001), and immediate reconstructions (p = 0.001). In the DIEP group, there was a higher percentage of smokers (p = 0.0001). There was a higher flap loss rate in both the SIEA and DIEP groups compared to the free TRAM group (p = 0.05). There was a decreasing rate of vessel thrombosis going from the SIEA group (17%) to the DIEP group (10%) to the free TRAM group (6.0%) (p = 0.003). The hernia rate was 0% in both the SIEA and DIEP groups, and 2% in the free TRAM group.

Conclusion: The SIEA group has the highest rate of vessel thrombosis, followed by the DIEP group, and then the MS fTRAM group. Both the SIEA and DIEP groups have a lower hernia/bulge rate than the MS fTRAM group. These findings are in line with theoretical risks and benefits for each procedure. Because of these pros and cons of each, the authors have no preferred reconstructive technique. Instead, an anatomic algorithm is proposed. First the SIEA pedicle is identified. If an SIEA is greater than 1.5 mm in diameter, has a pulse and a good vein, proceed with this flap, as long as only one half the abdominal skin island is required. If SIEA criteria are not met, save the SIEV and look for a dominant perforator. If a perforator bundle is identified that has a diameter of 2 mm or more, has a single accompanying vein, and has a palpable pulse, proceed with a DIEP. If DIEP conditions are not met, include a group of perforators and perform a muscle sparing free TRAM. The preferred method is to enter into each case with the goal of making intraoperative decisions that balance flap survival with donor site impact. This flexible approach will help insure consistently successful results in free flap breast reconstruction