title: In vivo assessment of the Combat Ready Clamp to control junctional hemorrhage in swine.
abstract: BACKGROUND
  Junctional wounds and associated hemorrhage have become more common and more lethal in the current war. The Combat Ready Clamp (CRoC) has been developed and deployed for treating junctional hemorrhage on the battlefield. This study examined the efficacy of CRoC and its acute effects in an animal model.
  
  
  METHODS
  Anesthetized pigs (n = 6) were subjected to laparotomy, splenectomy, and abdominal closure. Next, coagulopathy was induced in animals by hemodilution and hypothermia. The left femoral artery was isolated, punctured (6-mm hole), and allowed to bleed for 15 seconds. The groin wound was packed with gauze, and a CRoC applied and tightened until hemorrhage stopped. It was kept in place for 1 hour (treatment period) and then released for another hour or less (control-period) if animal exsanguinated. Fluid resuscitation was administered, and vascular blood flow was examined by Doppler and CT scans. After death, local tissues were collected for histology.
  
  
  RESULTS
  CRoC generated 800 to 900 mm Hg pressure on the wounds, which stopped the hemorrhage and prevented rebleeding during the first hour in all animals. Blood loss was minimal (≤137 mL), and mean arterial pressure remained at or higher than the target level (65 mm Hg) during this period. Removal of the clamp promptly led to rebleeding and exsanguination of five of six pigs during the second hour despite fluid resuscitation. Blood loss, survival, shock indices, and other measures were significantly (p < 0.01) different between the two periods. Doppler tests and CT scans showed no blood flow in the proximal, distal, and collateral arteries of the clamped leg. Minor inflammation was seen on blood vessels (endothelium) and nerves.
  
  
  CONCLUSIONS
  CRoC functioned as an effective hemostatic adjunct for compression and control of groin hemorrhage. Although no acute histological damages were seen in compressed tissues, the short- and long-term effects of CRoC application (e.g., total ischemia) on limb function remain unknown and warrant investigation.
authors.affiliation: US Army Institute of Surgical Research, Fort Sam Houston, Texas, USA. bijan.kheirabadi@amedd.army.mil
authors.forename: Bijan S
authors.initials: BS
authors.lastname: Kheirabadi
authors.forename: Irasema B
authors.initials: IB
authors.lastname: Terrazas
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Hanson
authors.forename: John F
authors.initials: JF
authors.lastname: Kragh
authors.forename: Michael A
authors.initials: MA
authors.lastname: Dubick
authors.forename: Lorne H
authors.initials: LH
authors.lastname: Blackbourne
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D058734:Exsanguination / Q000000981:diagnostic imaging / Q000628:therapy*; D005260:Female; D006119:Groin / Q000000981:diagnostic imaging / Q000293:injuries; D013552:Swine; D014057:Tomography, X-Ray Computed; D014111:Tourniquets; D016896:Treatment Outcome; D014463:Ultrasonography