Topical negative pressure therapy: Does it accelerate neovascularisation within the dermal regeneration template, Integra? A prospective histological in vivo study Naiem S. Moiemen a, *, Jeremy Yarrow a , Dia Kamel b , Daniel Kearns b , Derek Mendonca a a University Hospitals Birmingham NHS Foundation Trust, The Midlands Burn Centre, UK b Department of Histopathology, Birmingham University, Birmingham, UK 1. Introduction Integra (Life Sciences Corp., NJ) is a bilaminar dermal regeneration template (DRT). It consists of a temporary, superficial, silicone outer sheet and deep layer of bovine collagen and glycosaminoglycan. The deeper layer structure provides the ‘‘scaffold’’ for neodermis formation. Within the dermal template, host fibroblasts migrate, proliferate and then secrete a native collagen. Endothelial cells shortly follow the fibroblasts to form a vascular network within the neodermis [1]. The new ‘‘open’’ vascular channels provide the necessary metabolic support for the skin graft at the second stage. When vascularisation is sufficient to maintain and support an overlying split thickness skin graft, the silicon layer is burns 36 (2010) 764–768 article info Article history: Accepted 7 April 2010 Keywords: Integra Topical negative pressure Skin substitutes Histology, Vascularisation Dermal regeneration template abstract 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 vascu- larisation 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 neo- vascularisation as verified by the presence of histologically patent vascular channels. Crown Copyright # 2010 Published by Elsevier Ltd and ISBI. All rights reserved. * Corresponding author at: University Hospitals Birmingham NHS Foundation Trust, The Queen Elizabeth Medical Centre, Birmingham, UK. Tel.: +44 121 6278793. E-mail address: nmoiemen@aol.com (N.S. Moiemen). available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/burns 0305-4179/$36.00 . Crown Copyright # 2010 Published by Elsevier Ltd and ISBI. All rights reserved. doi:10.1016/j.burns.2010.04.011