A novel vacuum assisted closure therapy model for use with percutaneous devices

Abstract

Long-term maintenance of a dermal barrier around a percutaneous prosthetic device remains a common clinical problem. A technique known as Negative Pressure Wound Therapy (NPWT) uses negative pressure to facilitate healing of impaired and complex soft tissue wounds. However, the combination of using negative pressure with percutaneous prosthetic devices has not been investigated. The goal of this study was to develop a methodology to apply negative pressure to the tissues surrounding a percutaneous device in an animal model; no tissue healing outcomes are presented. Specifically, four hairless rats received percutaneous porous coated titanium devices implanted on the dorsum and were bandaged with a semi occlusive film dressing. Two of these animals received NPWT; two animals received no NPWT and served as baseline controls. Over a 28-day period, both the number of dressing changes required between the two groups as well as the pressures were monitored. Negative pressures were successfully applied to the periprosthetic tissues in a clinically relevant range with a manageable number of dressing changes. This study provides a method for establishing, maintaining, and quantifying controlled negative pressures to the tissues surrounding percutaneous devices using a small animal model.

Negative pressure wound therapy limits downgrowth in percutaneous devices

“…The control animals (Group 1 and 2) were singularly housed in standard rectangular cages (Model#1500 U Eurostand type IVS, Techniplast, East Goshen, PA) with top mounted water delivery systems and floor food bowls for unlimited access. The animals receiving NPWT regimen (Groups 3 and 4) were housed individually in custom designed cages (Figure A), which were previously used in a similar study . Briefly, they were transparent polycarbonate cylindrical cages that housed a side mounted water bottle and a feeding bowl.…”

“…Previously successful modular percutaneous devices were used for this study . This allowed the same implant system to be used for both One‐ and Two‐Stage surgical procedures.…”

“…This may be in part due to the lack of techniques for applying NPWT to percutaneous devices exit sites. Using a small animal model, methods were recently developed to reproducibly apply NPWT to PODS device exit sites and to maintain airtight dressings . This technique development now allows for more comprehensive and targeted percutaneous device related translational research strategies.…”

Influence of negative pressure wound therapy on peri‐prosthetic tissue vascularization and inflammation around porous titanium percutaneous devices

“…As described in previous studies, the implant exit site was covered with a sterile gauze and a semi‐occlusive base dressing in all the animals. Briefly, post‐surgery the skin was cleaned with sterile saline and gauze.…”

“…This tube allowed for the application of the negative pressure treatment directly to the gauze over the implantation site. To limit physical stress resulting from the NPWT delivery set‐up, custom designed cages based upon previously reported studies, were used [Figure (B)] . Briefly, the cages were designed with a rotary L‐fitting (Model RHL ¼‐N2U, PISCO Inc., Bensenville, IL) and a straight connector (Model PCF ¼‐N2U, PISCO Inc., Bensenville, IL), which allowed the animal unrestricted access to the entire cage.…”