PRELIMINARY EXPERIENCE WITH VOLUME ASSESSMENT IN BREAST ASYMMETRIES USING EXTERNAL 3D PRINTED SIZERS

Objective: Breast volume assessment is essential for surgical planning in patients with breast asymmetry. In search of a valuable method, we propose an external 3D printed breast sizer, which is accurate, easy to use, and acceptable for the patient. Methods: In collaboration with a 3D printing company, a set of breast sizers prototypes was developed with a reverse engineering process using anatomical MENTOR® CPGTM im- plants. The sizers were used for preoperative breast volume assessment in patients undergoing breast asymmetry cor- rective surgery. Breast resection volumes and breast im- plants volumes were also recorded. Patients’ satisfaction with breast symmetry pre- operatively and postoperatively was evaluated with a 10- point Visual Analogue Scale. At the six months follow-up, the authors re-evaluated breast symmetry using the 3D Sizers. Results: From 2019 to 2021, 35 patients were operated. Patients with Poland syndrome, unilateral amastia, chest wall deformities or requiring breast augmentation and contralateral reduction concurrently, were excluded. Twenty-eight patients were included, thirteen differential breast reduction, twelve differential breast augmentation and three unilateral breast reduction. The volume difference measured with the 3D Sizers preoperatively was compared to the differential volumes used to correct the breast asymmetry. Mann-Whitney U test showed no significant difference (p-value: 0.72). Mean preoperative satisfaction with breast symmetry was 3.79, while mean postoperative satisfaction was 8.79. T test showed significant difference (t = -15.22, p = < .00001). Postoperative re-evaluation with the 3D printed sizers at 6 months follow-up showed a perfect volume matching be- tween the breasts in all the patients. Conclusions: Our 3D printed sizers have proven to be accurate in volume difference measurement for breast asymmetries corrective surgery planning. They are non-in- vasive, easy to use and well accepted by the patients. Furthermore, the digital files for 3D printing can be made available for download and printed everywhere by other surgeons.