Histologic Features of Breast Capsules Reflect Surface Configuration and Composition of Silicone Bag Implants

Abstract

The fibrous capsules that develop around silicone gel breast implants may become excessively thickened and result in painful hardened breasts. This article examines the microscopic anatomy of 80 periprosthetic breast capsules removed during a 2-year period (1990-1992), and describes the histopathologic characteristics of capsules adjacent to the more recently modified implant types. Capsules were examined by routine light microscopy, with and without polarization. Several distinctive histologic patterns were recognized, and these unique patterns could be correlated with the implant type used. All capsules were lined by a cellular membrane resembling synovium. Capsules adjacent to smooth-surfaced implants were lined by an intact histiocytic membrane of uniform thickness. In contrast, the membrane adjacent to textured implants varied in thickness, and was disrupted along its length. In addition, the inner surface of capsules adjacent to textured implants was conspicuously festooned with small (.25 to .5 mm) knob-like projections that were not seen in capsules adjacent to smooth-surfaced implants. A variety of foreign materials also were observed either within or adjacent to the capsules, and included droplets of liquid silicone, irregular solid fragments of the bag envelope, geometric crystalline fragments of polyurethane, and talc. Thus, the microanatomic features of periprosthetic breast capsules reflect the composition and surface configuration of the corresponding silicone bag type.

Mice that lack the angiogenesis inhibitor, thrombospondin 2, mount an altered foreign body reaction characterized by increased vascularity

“…Nonporous biomaterials do not permit in-growth of connective tissue and vasculature and thus serve as excellent inducers of the FBR. The FBR to PDMS or silicone rubber is characterized by the formation of a collagenous capsule that can contract, often with undesirable effects on implants such as mammary prostheses (17). In its native state, PDMS is hydrophobic because of the sheath of methyl groups surrounding the -Si-O-backbone.…”

Reacción tisular a las prótesis mamarias: Contractura capsular periprotésica

“…Las células de cuerpo extraño son un tipo de células gigantes, y suelen tener gran cantidad de núcleos dispuestos irregularmente 7 . Son identificadas raramente en la reacción tisular a prótesis de silicona lisas 8 , excepto alrededor de materiales extraños procedentes de éstas, tales como gotas de gel de silicona 11 o partículas del elastóme-ro eliminadas 12 ( Fig. 2).…”

“…2). Las prótesis mamarias de silicona con superficie microporosa, como la texturada Biocell, promueven el crecimiento tisular dentro de la superficie, provocando una reacción inflamatoria crónica, con macrófagos y células gigantes, a menudo rodeando algunas partículas de silicona 12,13 . Una reacción similar se ha observado de forma significativa, formando granulomas, con prótesis de silicona asociadas a materiales biodegradables, como el poliuretano 12 .…”

“…En estudios clínicos se ha descrito el desarrollo de una metaplasia sinovial alrededor de prótesis mamarias, lisas o texturadas 12,[17][18][19][20] , similar a la observada en el tejido adyacente a prótesis articulares, tendinosas o de otros tipos 21 ( Fig. 3).…”

“…Tienen una superficie texturada de silicona microporosa, con proyecciones y cavidades irregulares. Las proyecciones tienen una altura de 500 a 800 µm, el diámetro de las cavidades oscila entre 300 y 800 µm y su profundidad entre 200 y 350 µm 3,5,12,27 (Fig. 5) texturadas.…”