217 A RE-EVALUATION OF TISSUE VIABILITY OF TRANSVERSE RECTUS ABDOMINIS MUSCULOCUTANEOUS FLAPS DURING UNILATERAL MASTECTOMY BREAST RECONSTRUCTION.

Purpose One out of every eight women is diagnosed with breast cancer, making it the most prevalent type of cancer in women. A significant portion of women choose to undergo mastectomy; the subsequent deformities lead to the desire for breast reconstruction. The options for breast reconstruction include prosthetic implant, autologous tissue, or a combination of both. The transverse rectus abdominis musculocutaneous flap (TRAM) is a well-known technique that has been established as one of the mainstays of autogenous breast reconstruction. Evaluation of the TRAM flap viability is a highly desired criterion, but one that is clinically difficult to assess intraoperatively. A new technique which employs the novel device the ODISsey TM Tissue Oximeter (Optical Imaging and Diffusion Spectroscopy), which measures tissue oxygenation saturation at the capillary level, allows real-time evaluation of blood perfusion and therefore provides a tangible measurement of perfusion to each zone. Methods Three patients who had previously undergone a unilateral mastectomy desired reconstruction using autologous tissue and were felt to be good candidates for a TRAM flap reconstruction. Measurements for tissue oxygenation were taken with the ODISsey Tissue Oximeter prior to elevation of the flap and after ligation of the inferior epigastric artery in each of the four zones. Results The pre-ligation numbers were similar in all four zones as would be expected. However, the tissue oxygen saturation was consistently higher in zone III than in zone II. Conclusion In our studies the use of the ODISsey Tissue Oximeter was shown to be a quick and safe technique to reliably evaluate blood perfusion to a particular area of tissue. Our analysis shows that although Zone II has traditionally been thought to have better perfusion than zone III, we found that, in fact, Zone III had better perfusion after ligation of the inferior epigastric artery. This allowed us to preserve more tissue for breast reconstruction. Further studies are currently under way to re-define the perfusion zones.