Capsule histology in breast reconstruction: different materials lead to different tissue responses - a case series

Implant-based breast reconstruction currently offers a wide range of options due to the availability of different biomaterials; however, their biological impact on the peri-prosthetic tissue environment has not yet been fully clarified. This study aims to comparatively evaluate the tissue responses associated with different implant-tissue interfaces.

Tissue samples obtained from 11 patients who underwent breast reconstruction using various devices were analyzed, including tissue expanders, smooth and textured silicone implants, polyurethane (PU)-coated implants, acellular dermal matrices (ADM), acellular pericardial matrices (APM), and titanised polypropylene meshes (TCPM). Histological analyses performed using hematoxylin-eosin and Masson's trichrome staining evaluated inflammation, collagen organization, neovascularization, and foreign body response.

The findings demonstrated distinct tissue responses depending on the implanted material. ADMs were associated with minimal inflammation, organized collagen architecture, and evidence of neovascularization and tissue integration. In contrast, synthetic materials such as TCPM and PU induced chronic inflammation of varying intensity, foreign body granulomatous reactions, extensive fibrosis, and persistence of the material. APMs and both smooth and textured implants showed intermediate patterns, characterized by material persistence and variable chronic inflammatory infiltrates. Smooth implants were associated with more mature, organized, and less cellular fibrous capsules.

Overall, material composition, structural properties, and interface continuity appear to play a key role in modulating the behavior of the surrounding tissue. These findings indicate that implantable materials are not biologically equivalent and suggest that their selection should take into account not only mechanical aspects but also their biological profile. A better understanding of these interactions may help optimize reconstructive outcomes and reduce long-term complications, such as capsular contracture.