Marsupialization of percutaneous implants in presence of deep connective tissue

Abstract

The primary substratum for epithelial migration during marsupialization of percutaneous implants is adjacent connective tissue. The purpose of this investigation was to test the hypothesis that if the latter is composed of deep connective tissue or other deep tissue, it will inhibit this process. One-hundred-forty-two smooth-surfaced polyethylene implants of a simple geometric design were implanted in dorsal skin of 6-8-week-old male C57/BL/6 mice such that the stems passed through and deep to the panniculus carnosus (PC), which is a deep tissue. Animals were sacrificed in groups between 1 and 11 weeks, and the implants and surrounding tissue were harvested, embedded in historesin, and 3-microns thick step serial sections prepared. No implants were lost by extrusion and 133 were suitable for examination. Epithelial investment of the devices proceeded deep to PC around only five of the implants over the time course. In the remainder, the mean distance of the advancing epithelial edge from the upper border of the PC was 0.25 mm by 1 week and this did not change significantly thereafter (p = 0.647). Significant extrusion of all devices occurred (p = 0.0001). It was concluded that these results are consistent with the hypothesis that deep connective tissue, such as the fascia surrounding the PC or muscle tissue such as the PC itself, can act as a functional barrier to marsupialization, and that exfoliation of such devices is not an epithelial function.

In situ optical coherence tomography of percutaneous implant-tissue interfaces in a murine model

“…This non-contact optical technique enabled observation of the morphological changes due to, e.g., inflammation, without impairing the biological mechanisms. Repetitive measurements on the same animal were possible and allowed for the monitoring of the ongoing immune reaction, as the animals did not need to be killed like in previously published work [6].…”

“…To avoid inflammation, different implant designs and coatings were developed and tested in biocompatibility studies in animal models [19,20,24]. Morphological features such as epithelial downgrowth and the inflammatory response were analyzed in histological images obtained from tissue sections [6]. One drawback of the study protocol is the high animal consumption for the time-dependent monitoring of foreign body reaction.…”

“…One drawback of the study protocol is the high animal consumption for the time-dependent monitoring of foreign body reaction. Another limitation arises from the embedding and preparation artifacts during histological procedures, which limits the number of sections available for quantitative analysis [6]. Using non-contact in vivo imaging for postoperative monitoring of the implant-tissue interface would lead to a more efficient study protocol with reduced animal numbers.…”

Failed Tube Extrusion is Not a Random Event in Children or Their Siblings

“…Biocompatible materials resist extrusion by the formation of a surrounding tissue capsule 15 . By contrast, percutaneous implants undergo progressive epithelial investment that leads to extrusion driven by the forces of epithelial migration 16 …”

Collagen immobilization onto the surface of artificial hair for improving the tissue adhesion

“…However, conventional non-porous, polymeric materials that are percutaneously implanted are readily encapsulated by granulated tissue and then by a brous membrane generated de novo by the surrounding broblasts. This is followed by epidermal down-growth along the implant surface [2]. Such processes prevent rm bonding at the interface between the implant and the tissue.…”