BACKGROUND: In free flaps with visible skin paddles, the skin color difference between the recipient and donor sites should be considered to improve the aesthetic outcomes. This study aimed to investigate whether the preoperative color difference, detected using colorimetric analysis, between the breast and abdomen affects the aesthetic result in unilateral breast reconstruction with free abdominal flap. METHODS: This study was designed as a cohort study. Average color samples of the skin paddle, ipsilateral breast, and preoperative abdomen were obtained. The group where the delta-E value between the breast and abdomen was >
4 preoperatively and the group where it was not compared (patients with clear difference vs. those without clear difference). Basic characteristics and delta-E values in both groups were compared preoperatively, 6 months postoperatively, and >
2 years postoperatively. RESULTS: The groups with and without clear differences included 102 and 46 patients, respectively. The group with clear differences had significantly high preoperative mean delta-E (6.75 ± 1.97 vs. 2.80 ± 0.76, P <
0.001). Although delta-E was not significantly different at 6 months postoperatively, it was significantly low in the group without a clear difference (3.83 ± 1.96 vs. 2.83 ± 1.47, P = 0.002) at >
2 years postoperatively. No significant differences in other characteristics were noted. The multivariate analysis revealed that preoperative delta-E (odds rate = 1.242, P = 0.003) was independently a significant predictor. CONCLUSIONS: In the long-term follow-up, cases without clear skin color differences preoperatively between the breast and abdomen showed good aesthetic outcomes. TAKE HOME MESSAGE: For breast reconstruction of a free abdominal flap with a visible skin paddle, cases without clear preoperative color differences between the breast and abdomen showed good aesthetic outcomes in >
2 years postoperatively when assessed using colorimetric analysis.