Background: The pedicled transverse rectus abdominis myocutaneous flap (PTRAM) remains the most commonly used method of autologous breast reconstruction. The PTRAM derives its blood supply from the superior epigastric artery, which has been shown to be the secondary blood supply to the tissue of the anterior abdominal wall. TRAM flaps subject a patient to significant abdominal wall morbidity because they require removal of all or part of the rectus abdominis muscle. A search for a less invasive technique of flap harvesting led to the development of the free deep inferior epigastric perforator flap (DIEP), which is based on the vascular territory of the deep inferior epigastric artery, the primary vascular conduit to the lower anterior abdominal wall. The technically more challenging DIEP flap harvests the deep inferior epigastric artery and veins that perfuse the lower abdominal wall skin and fat and minimizes damage to the rectus abdominis muscles. Studies comparing similar and sizable numbers of DIEP and PTRAM flap reconstructions are lacking. This study seeks to determine whether the DIEP flap truly has significant advantages to the PTRAM flap for breast reconstruction.
Methods: We retrospectively reviewed the records of women undergoing breast reconstruction after mastectomy over a nine-year period at a single institution. Patients were grouped according to type of reconstruction: DIEP or PTRAM. Only patients with unilateral breast reconstructions and at least three months of postoperative follow-up were included in this study. The PTRAM was used exclusively at this institution for the first six years studied, while only the DIEP was employed for breast reconstruction during the last three years reviewed. Complications were divided into flap or donor-site complications. Statistical analysis was performed on all of our collected data. The group rates and means were compared between the groups. The Chi-square statistic and Fishers Exact test were used to analyze the group rates for statistically significant differences. The one-way ANOVA was used to analyze the group means for significance.
Results: One hundred ninety women underwent unilateral breast reconstructions. Ninety-six women had DIEP flaps, while 94 women had PTRAM flaps. The patient groups were similar in terms of age, body mass index, preoperative medical illness, history of abdominal surgeries, cancer stage and history of preoperative chest wall irradiation. Median hospital stay was shorter for the DIEP (4 days) than for the PTRAM (5 days). Mean operative time for the DIEP (5:53 hours) was longer than for the PTRAM (4:46 hours). Fat necrosis rates were significantly higher for the PTRAM (58.5%) than for the DIEP (17.7 %). Abdominal wall hernias were significantly more common in the PTRAM (16.0%) patients than in the DIEP patients (1.0 %). Abdominal wall bulging rates were similar for both groups.
Conclusions: What is unique to this study is that once the DIEP was used for breast reconstruction at this institution, it was used exclusively. No TRAM flaps were performed during the time period in which the DIEP was performed. Since selection criteria were not used to screen the patients for either a DIEP or a TRAM flap reconstruction, this data set is less likely to have suffered from the selection bias that has plagued other studies comparing the DIEP to the TRAM. Patients receiving DIEP flaps experienced outcomes that were as good as or better than the PTRAM patients in every measure of surgical outcome. Specifically, the moderately increased operative time and complexity required for a DIEP flap reconstruction translated into shorter hospital stays, less fat necrosis, and fewer abdominal wall hernias than was seen in the PTRAM patients. This data supports the DIEP as the preferred option over the PTRAM for autologous breast reconstruction in the post-mastectomy patient.