Evaluation of the Relationship Between Flap Tension and Tissue Perfusion in Implant-Based Breast Reconstruction Using Laser-Assisted Indocyanine Green Angiography

For implant-based breast reconstruction, inadequate tissue perfusion may cause devastating complications. Tissue tension by inadequate implant volume may reduce tissue perfusion by stretching and collapsing the capillaries. The SPY system is used to perform intraoperative fluorescence angiography with indocyanine green to assess visually the blood flow and evaluate tissue perfusion. However, there is no report yet about how mastectomy flap perfusion changes with the expander-filling volume. Therefore, to analyse the changes of tissue perfusion of the mastectomy flap according to the tension level, we used the SPY system and adjusted the filling volume of the tissue expander to change the tension on the skin flap. Ten breasts of ten patients who underwent immediate two-stage, implant-based breast reconstructions were included. The expander-filling volume just before mastectomy flap blanching was set as 100%. Based on this, the expander-filling volume was reduced to 50% and increased to 150%. Ingress and egress rates were evaluated using the SPY system at each condition and analysed by a linear mixed model using least square means. The mean ingression rates were 138, 100, and 65%, and the mean egression rates were 145, 100, and 66% at 50, 100, and 150% inflation, respectively. It was objectively proven that tissue perfusion deteriorates as the tension applied on the flap increases. On the basis of this finding, we can control the amount of inflation volume of the expander or remove the skin in the pre-ischaemic condition to reduce complications of implant-based breast reconstruction.