Indocyanine Green Angiography Predicts Postoperative Volume Changes in DIEP Flap Breast Reconstruction

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

This retrospective cohort study included 44 patients who underwent unilateral breast reconstruction with unipedicled DIEP flaps between September of 2019 and February of 2024. Intraoperative flap perfusion was assessed using ICG angiography, and the ICG flow inset ratio was calculated. Flap volume was measured intraoperatively and about 1 year postoperatively using magnetic resonance imaging. Multivariable linear regression and receiver operating characteristic analysis were performed to identify predictors of volume preservation.

The average flap volume at 1 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); radiotherapy was correlated with increased volume loss (β = -0.155; P < 0.001). The optimal ICG flow inset ratio cutoff for predicting above-average volume maintenance was 1.325 (area under the receiver operating characteristic curve = 0.700).

ICG angiography can guide intraoperative decision-making to optimize postoperative volume outcomes in breast reconstruction. 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.