Method for assessing the viability boundaries of a DIEP flap using near-infrared spectroscopy in breast reconstruction

Introduction. Breast reconstruction using a DIEP flap is associated with a risk of ischemic complications, requiring objective intraoperative perfusion control. Existing monitoring methods are either subjective or aimed at the postoperative period. The purpose of this study. To develop and evaluate the effectiveness of a method for intraoperative determination of the viability boundaries of a DIEP flap using near-infrared spectroscopy (INVOS). Materials and methods. A prospective study included 28 patients who underwent breast reconstruction with a DIEP flap. Intraoperatively, using the INVOS 5100C system, regional oxygen saturation (rSO₂) was measured in four zones of the flap before pedicle division (target values), as well as after reperfusion. A viability criterion was an rSO₂ value of ≥60 %. Areas with values below 60 % were resected. Research results and discussion. The mean rSO₂ values in zones I and II after reperfusion were 78,5±6,2 % and 72,1±8,4 %, respectively, which did not significantly differ from the target values. In zones III and IV, a decrease in rSO₂ below 60 % was observed in 11 (39,3 %) patients, requiring economical resection of the distal flap parts. The incidence of marginal necrosis in the postoperative period was 3,6 % (1 case). Conclusion. The use of INVOS spectroscopy with a threshold rSO₂ value of 60 % allows for an objective and non-invasive determination of the viable part of a DIEP flap intraoperatively, minimizing the risk of ischemic complications.