Fat Necrosis in Deep Inferior Epigastric Perforator Flaps: Review of 202 Cases

Fat necrosis remains one of the complications after autologous breast reconstruction. The knowledge is limited, because previous studies used vague and diverse definitions, and were based on physical examination only. In this study, 202 deep inferior epigastric perforator (DIEP) flaps for breast reconstruction were evaluated with respect to fat necrosis. The findings on the prevalence of fat necrosis were not only based on a physical examination, but also on ultrasound imaging. Physical examination revealed a palpable mass or focal thickening of the flap in 28 patients (13.8%). Ultrasound examination added another 43 patients (21.2%) with formation of a firm area of scar tissue with a diameter ≥ 5 mm. However, 7.5% of patients underwent a surgical procedure to remove the area of fat necrosis, of which 2% were under general anesthesia and 5.5% were under local anesthesia. For the two findings, under clinical examination and untrasound imaging, the following explanatory variables were checked in logistic regression models: age, smoking, body mass index, timing of the reconstruction, and timing and extent of radiation therapy fields. In contrast to previous studies, none of these variables were statistically significant for the occurrence of fat necrosis. These results also suggested that there is no need for a delayed reconstruction in patients who need post-mastectomy radiation therapy.