EXPERIMENTAL Analysis of Nerve and Neuropeptide Patterns in Vacuum-Assisted Closure–Treated Diabetic Murine Wounds George Younan, M.D. Rei Ogawa, M.D., Ph.D. Michelle Ramirez, B.A. Douglas Helm, M.D. Pouya Dastouri, M.D. Dennis P. Orgill, M.D., Ph.D. Boston, Mass.; and Tokyo, Japan Background: Reestablishment of the peripheral nervous system occurs in parallel with wound healing. With accelerated wound healing seen with the vacuum-assisted closure device, the authors studied its effects on nerve fiber regeneration, nerve sprouting, and the stimulation of neuropeptides and neurotrophins. Methods: A vacuum-assisted closure device was applied to a full-thickness diabetic mouse wound using continuous or cyclical modes and compared with foam dressing or occlusive dressing controls, using 10 mice per group. Nerve fibers, substance P, calcitonin gene-related peptide, and nerve growth factor were analyzed using two-dimensional immunohistochemistry and real- time reverse-transcriptase polymerase chain reaction. Results: A significant increase in dermal and epidermal nerve fiber densities and in substance P, calcitonin gene-related peptide, and nerve growth factor expression was seen in vacuum-assisted closure–treated wounds. Cyclical treatment mode correlated with the largest increase in granulation tissue production, wound surface microdeformations, and a slightly faster wound closure rate. Conclusions: This study suggests that vacuum-assisted closure therapy can modulate nerve fiber and neuropeptide production in the wound. Optimized kinetics of vacuum-assisted closure application may provide an opportunity for clinicians to further improve wound healing in denervated wounds such as pressure sores and diabetic foot ulcerations. (Plast. Reconstr. Surg. 126: 87, 2010.) T he neurocutaneous axis is the communication link between the nervous system and the skin (Fig. 1) and has a critical role in directing normal wound healing. 1,2 Skin denervation, whether surgical, chemical, or pathologic, is linked directly to delayed wound healing in experimental animal studies. 3–5 Likewise, poor wound healing is observed clinically in patients with neurologic dysfunction, including pressure sores from spinal cord injuries. 1,6 Diabetic neuropathy is linked to chronic nonhealing ulcers. 3–5,7 Epidermal nerve fiber density, which is decreased in diabetics, is used to predict the level of peripheral neuropathy. 8,9 Several studies have previously correlated de- creased quantity of epidermal and dermal nerve fibers and the principal neuropeptides released from nerve terminals including substance P, cal- citonin gene-related peptide, and the neurotro- phin nerve growth factor (NGF) levels to wound healing. 10,11 Animal wound models show restitu- tion of the neurotransmitter factors reconstituting the wound repair pathway. Likewise, clinical ap- From the Division of Plastic Surgery, Brigham and Women’s Hospital, Harvard Medical School, and the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Med- ical School. Received for publication July 30, 2009; accepted January 6, 2010. Copyright ©2010 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0b013e3181da86d0 Disclosures: Dr. Orgill is the principal investigator on studies receiving research grants to the Brigham and Women’s Hospital by Kinetic Concepts, Inc., San Antonio, Texas, and is also an expert witness for Kinetic Concepts, Inc. The bioreactor used in this study, suction apparatus, and foam were provided by Kinetic Concepts, Inc. The other authors have no financial conflicts of interest and do not have any financial or business liaison to Kinetic Concepts, Inc. www.PRSJournal.com 87