Visual Perception of Breast Free Flap Size Is Influenced by Radiation Changes of Surrounding Tissue.

Background:  Microsurgical reconstruction for bilateral mastectomy defects after unilateral radiation often results in asymmetry, despite both flap tissues never being radiated.

Methods:  Photos of 16 patients who received prior radiation to one breast and underwent bilateral abdominal free flap reconstruction were taken postoperatively. Layperson and expert assessment were attained via online crowdsourcing and a panel of attending surgeons and senior residents. Stratification by interflap weight differences was done for subanalysis.

Results:  A total of 399 laypersons responded, with the majority (57.3%) reporting that the radiated breast appeared smaller than the nonradiated breast. When the photos were stratified by interflap weight differences, the photos with the radiated side flap weight over 3% more than nonradiated side were significantly more likely to be perceived by laypersons as the same size (odds ratio [OR] = 2.7;  < 0.001) and of similar aesthetic (OR = 1.9;  < 0.001) when compared with photos with same-sized flaps. Of the expert responses ( = 16), the radiated side was perceived as smaller 72.3% of the time and the nonradiated side appeared more aesthetic 52.7% of the time. Contrary to layperson responses, the experts tend to report the radiated side as smaller despite varying flap weight. Interestingly, expert raters were significantly more likely to rate the flaps of equal aesthetics when the radiated side has a flap larger by 3% or more (OR = 3.6;  < 0.001).

Conclusion:  Higher aesthetic scores were noted when larger flaps were inset to the radiated envelope by both laypersons and experts, suggesting potential technical refinement in reconstructive outcomes.