(M-503) A Novel Smooth Breast Implant Surface that Promotes Tissue Adherence and Implant Stability

Introduction:: The FDA's recommended voluntary recall of textured breast implants due to their association with Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL) has led to a loss of one of the major benefits of the textured surface: positional stability for anatomically shaped implants. Inspired by clinical observation of tissue ingrowth into cranioplasty plates with millimeter size pores to allow fluid egress, our group has engineered a novel soft gel-filled smooth breast implant surface that provides positional stability without texture, known as Positionally Stable Smooth Implants (PSSI). Our novel design promotes tissue ingrowth into the implant shell which contains cylindrical “wells” 1-4mm in diameter, thereby fixing the implant into position as the implant capsule forms. In this study, we report our early findings on the positional stability of this novel smooth implant design implant.


Materials and Methods:: Anatomically shaped miniature 2cc breast implants were fabricated using polydimethylsiloxane. 3D-printed molds designed using CAD modeling were casted. The implant shell design incorporates cylindrical invaginations/wells 1-4mm in diameter. Shells were designed with wells in the following variations in width (W), depth (D), total surface well count (P), and reported in millimeters: W1D2 22P, W2D2 11P, W2D2 22P, W2D3 22P, W4D2 11P (Fig. 1a). Control groups consisting of smooth and salt-imprinted textured surfaces topographically comparable to commercial implants were fabricated. Five sterilized implants per group were implanted into a tight subcutaneous pocket on the dorsa of Sprague-Dawley rats. Rotation was measured every 2 weeks for a total of 8 weeks to assess stability. Animals were sacrificed at 1 month, and implant-capsule unit was explanted en bloc for positional, histological, and micro-CT analysis.


Results, Conclusions, and Discussions:: Results/Discussions
All PSSI conditions demonstrated tissue ingrowth into well features by 1 month after implantation as demonstrated through hematoxylin and eosin staining and Micro-CT imaging. The ingrown tissue conformed completely to the shape of the well and tissue density was consistent among PSSI conditions. Two months post implantation, textured implants, W2D3 22P, and W4D2 11P demonstrated statistically significant greater stability compared to smooth implants (p< 0.05) (Fig. 1b). Lower stability was observed with decreased well width and depth. No significant differences were observed between groups in capsule thickness or collagen content upon histologic evaluation.

Conclusions
This novel breast smooth implant design with cylindrical well features significantly improved implant position stability without the use of traditional microtextured technology which is linked to BIA-ALCL. There was similar stability between PSSI and textured implants. These initial results suggest a promising alternative to microtextured surfaces for inducing positional stability in breast implants. Further studies, of longer duration and using larger implants, are ongoing to determine the optimal well configuration and density that maximizes implant stability.


Acknowledgements (Optional): :

References (Optional): :