Indocyanine green angiography predicts postoperative volume changes in deep inferior epigastric artery perforator flap breast reconstruction.

[BACKGROUND] Deep inferior epigastric artery perforator (DIEP) flaps are commonly used in breast reconstruction due to their muscle-sparing nature. However, postoperative volume changes can impact long-term breast symmetry. This study evaluated the predictive value of intraoperative indocyanine green (ICG) angiography findings for postoperative volume changes in DIEP flaps.

[METHODS] This retrospective cohort study included 44 patients who underwent unilateral breast reconstruction with unipedicled DIEP flaps between September 2019 and February 2024. Intraoperative flap perfusion was assessed using ICG angiography, and the ICG flow inset ratio was calculated. Flap volume was measured intraoperatively and about one year postoperatively using MRI. Multivariable linear regression and receiver operating characteristic (ROC) analysis were performed to identify predictors of volume preservation.

[RESULTS] The average flap volume at one year was 85.2% of the initial volume. Higher ICG flow inset ratios were significantly associated with better volume preservation (β = 0.083, P = 0.047), while radiotherapy correlated with increased volume loss (β = -0.155, P < 0.001). The optimal ICG flow inset ratio cut-off for predicting above-average volume maintenance was 1.325 (area under the ROC curve = 0.700).

[CONCLUSIONS] Higher intraoperative ICG flow inset ratios predict improved long-term volume preservation in DIEP flap breast reconstruction. Targeting a ratio above 1.325 and careful flap design may support better symmetry, particularly in patients undergoing radiotherapy.Clinical relevance statement: ICG angiography can guide intraoperative decision-making to optimize postoperative volume outcomes in breast reconstruction.