LAUSR

BACKGROUND For patients who are unable to undergo nipple-sparing mastectomy, reconstruction of the nipple-areolar complex (NAC) has been shown to promote greater satisfaction in cosmetic outcome, body image and sexual relationships. Although there have been a variety of techniques developed to optimize the shape, size, and mechanical properties of the reconstructed NAC, maintenance of sustained nipple projection over time remains a challenge for plastic surgeons. METHODS 3D-printed Poly-4-Hydroxybutyrate (P4HB) scaffolds were designed and fabricated then 1) filled with either mechanically minced or zested patient-derived costal cartilage (CC) 2) designed with an internal P4HB lattice (rebar) to provide interior structure to foster tissue ingrowth or 3) left unfilled. All scaffolds were wrapped within a CV flap on the dorsa of a nude rat. RESULTS One year after implantation, neo-nipple projection and diameter was well preserved in all scaffolded groups compared to non-scaffolded neo-nipples (p<0.05). Histologic analysis showed significant vascularized connective tissue ingrowth at 12 months in both empty and rebar scaffolded neo-nipples and fibrovascular cartilaginous tissue formation in mechanically processed CC-filled neo-nipples. The internal lattice promoted to more rapid tissue infiltration and scaffold degradation, and best mimicked the elastic modulus of the native human nipple after one year in vivo. No scaffolds extruded or caused any other mechanical complications. CONCLUSION 3D printed biodegradable P4HB scaffolds maintain diameter and projection while approximating the histologic appearance and mechanical properties of native human nipples after one year with a minimal complication profile. These long term pre-clinical data suggest that P4HB scaffolds may be readily translated for clinical application.