title: The SNaP system: biomechanical and animal model testing of a novel ultraportable negative-pressure wound therapy system.
abstract: BACKGROUND
  Negative-pressure wound therapy is traditionally achieved by attaching an electrically powered pump to a sealed wound bed and applying subatmospheric pressure by means of gauze or foam. The Smart Negative Pressure (SNaP) System (Spiracur, Inc., Sunnyvale, Calif.) is a novel ultraportable negative-pressure wound therapy system that does not require an electrically powered pump.
  
  
  METHODS
  Negative pressure produced by the SNaP System, and a powered pump, the wound vacuum-assisted closure advanced-therapy system (Kinetic Concepts, Inc., San Antonio, Texas), were compared in vitro using bench-top pressure sensor testing and microstrain and stress testing with pressure-sensitive film and micro-computed tomographic scan analysis. In addition, to test in vivo efficacy, 10 rats underwent miniaturized SNaP (mSNaP) device placement on open wounds. Subject rats were randomized to a system activation group (approximately -125 mmHg) or a control group (atmospheric pressure). Wound measurements and histologic data were collected for analysis.
  
  
  RESULTS
  Bench measurement revealed nearly identical negative-pressure delivery and mechanical strain deformation patterns between both systems. Wounds treated with the mSNaP System healed faster, with decreased wound size by postoperative day 7 (51 percent versus 12 percent reduction; p < 0.05) and had more rapid complete reepithelialization (21 days versus 32 days; p < 0.05). The mSNaP device also induced robust granulation tissue formation.
  
  
  CONCLUSIONS
  The SNaP System and an existing electrically powered negative-pressure wound therapy system have similar biomechanical properties and functional wound-healing benefits. The potential clinical efficacy of the SNaP device for the treatment of wounds is supported.
authors.affiliation: Stanford and Sunnyvale, Calif. From the Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford University; the Department of Bioengineering, Stanford University; and Spiracur, Inc.
authors.forename: Kenton D
authors.initials: KD
authors.lastname: Fong
authors.forename: Dean
authors.initials: D
authors.lastname: Hu
authors.forename: Shaundra
authors.initials: S
authors.lastname: Eichstadt
authors.forename: Deepak M
authors.initials: DM
authors.lastname: Gupta
authors.forename: Moshe
authors.initials: M
authors.lastname: Pinto
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Gurtner
authors.forename: Michael T
authors.initials: MT
authors.lastname: Longaker
authors.forename: H Peter
authors.initials: HP
authors.lastname: Lorenz
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004867:Equipment Design; D006097:Granulation Tissue / Q000502:physiology; D054843:Negative-Pressure Wound Therapy / Q000295:instrumentation; D011312:Pressure; D051381:Rats; D014618:Vacuum; D014945:Wound Healing