Spontaneous Reinnervation of Deep Inferior Epigastric Perforator Flaps after Delayed Breast Reconstruction

Background The spontaneous reinnervation of free flaps, such as deep inferior epigastric perforator (DIEP) flaps, is not fully understood, and few publications have investigated this issue. The aim of this study was to examine spontaneous reinnervation following breast reconstruction with autologous DIEP flaps without an additional nerve transfer. Methods In a retrospective clinical study, 18 female patients were investigated for a mean of 49.59 months (range, 12-88 months) following breast reconstruction with a unilateral DIEP flap. Five sensory modalities were tested: pressure perception, dynamic two-point discrimination, sharp-blunt discrimination, hot and cold discrimination, and vibration perception threshold (VPT). The measurements were performed on the reconstructed breast, flap surrounding transition zone, healthy contralateral breast, and the donor site. For a more precise analysis all breasts have been divided into five different segments (mediocranial, laterocranial, mediocaudal, laterocaudal, and reconstructed nipple areola complex, if present). Additionally, tissue oxygen saturation and tissue hemoglobin were measured by laser Doppler spectroscopy. Results Spontaneous reinnervation of at least one modality tested was observed in all DIEP flaps (n = 18). This sensitive recovery increases over the postoperative period. The maximum difference between the controls and DIEP flaps was observed in cold perception, whereas the least difference was observed in the VPT. Regarding the different segments, we observed better sensitive recovery in the cranial parts of the DIEP flaps and the transition zone. Conclusion This study provides certain predictions for patients and surgeons, when and to which extent spontaneous reinnervation can be expected.