Topical negative pressure therapy: does it accelerate neovascularisation within the dermal regeneration template, Integra? A prospective histological in vivo study.

Background: The use of topical negative pressure (TNP) dressings with dermal regeneration template (DRT), Integra, has improved outcomes and simplified aftercare. Previous clinical studies have suggested accelerated vascularisation; with a reduction in the duration of the 1st stage after the application of Integra, from 2 to 4 weeks to as little as 4 days, but with no histological evidence. However, histological studies, without TNP, have shown that vascularisation occurs between the second and the fourth week. This study set out to examine histologically the rate of DRT neovascularisation when combined with TNP.

Methods: Eight patients with nine reconstruction sites were enlisted. Unmeshed Integra and fibrin sealant to promote adherence were used. TNP was applied for the duration between the 1st and the 2nd stages. Patients underwent serial biopsies on days 7, 14, 21 and 28 post-application. The biopsies were stained with H&E and endothelial markers CD31 and CD34. Template vascularisation was assessed as a percentage of the template depth in which patent, canalised vascular channels could be demonstrated.

Results: The median percentage of the template depth which demonstrated canalised channels was 0%, 20%, 61% and 80% for days, 7, 14, 21 and 28, respectively.

Conclusion: The application of TNP dressings to dermal templates can reduce shearing forces, restrict seroma and haematoma formation, simplify wound care and improve patient tolerance. However, this study could not demonstrate that TNP accelerates neovascularisation as verified by the presence of histologically patent vascular channels.