Pillared‐surface microstructure and soft‐tissue implants: Effect of implant site and fixation

Abstract

Previous work with subcutaneous implants in a rat animal model has shown that pillarlike surface microstructure will reduce fibrosis and enhance blood vessel approximation to the implant surface when compared with nontextured controls. This study was designed to determine the effect of microtissue anatomy and implant site on the observed response, as well as the effect of implant fixation. The lateral posterior sites were found to contain a fat pad which produced a dramatically reduced fibrosis for the microstructured implants compared with smooth controls. Al-though significant differences between pillar-microstructured implants and controls were found for most sites, neither fascia nor muscle reduces the level of cellular response to the same degree as fat. Suture fixation of the implants did not produce a significantly different response in these tests. The occupation of the interpillar spaces by fat and moderation of interfacial shear forces is proposed as a mechanism to explain these results. 0 1996 John Wiley & Sons, Inc.

Percutaneous implants with porous titanium dermal barriers: An in vivo evaluation of infection risk

“…As seen in previous studies, tissue attachment to subcutaneous implants is increased when the implant is roughened or porous coated 10, 31, 53–55. In a study performed by Kim and colleagues, surfaces with varying roughness or grooves resulted in greater tissue attachment and less fibrous capsule formation compared to the smooth surfaces, which had a thick fibrous capsule formation, similar to the presented results.…”

“…Smooth surface implants have less surface area for tissue attachment, and the fibrous capsule which develops around the surface allows the implants to move within the soft tissue making it difficult for any soft tissue seal to form 53. It is generally believed that any “mechanical irritation” produced by stress and movement at an implant interface yields a thicker fibrous capsule formation 31, 53, which was observed in this study. The absence of soft tissue attachment to the smooth surfaces was seen during the histological processing as the tissue would separate from the implant; whereas, this was not observed with the porous implants.…”

“…The result is an incomplete barrier to preventing microbial migration and subsequent infection. Smooth surface implants have less surface area for tissue attachment, and the fibrous capsule which develops around the surface allows the implants to move within the soft tissue making it difficult for any soft tissue seal to form 53. It is generally believed that any “mechanical irritation” produced by stress and movement at an implant interface yields a thicker fibrous capsule formation 31, 53, which was observed in this study.…”

Pore size in implanted polypropylene filters is critical for tissue organization

“…The most probable source for the foreign body induction is the macrophages close to the filter surface. Surface characteristics of the filters then become more important, and a biomaterial with a surface structure that allows ingrowth of the surrounding tissue will likely make the initial inflammatory reaction subside and become incorporated into tissue 35, 36. An important factor in these events is most probably the mechanical stability2, 7 at the implant–tissue interface, where a persistence of interfacial shear will sustain the inflammatory reaction and foreign body capsule formation 22, 37…”

Cell and tissue behavior on micro-grooved surfaces

“…Accordingly, silicone implants provided with pillars and pits of 2 to 8 mm showed less mononuclear cell attachment, and resulted in a thinner capsule. Similarly, Picha and coworkers 81 found that large (500-mm) pillars reduced inflammation and capsule formation around silicone implants.…”