title: Can contrast-enhanced ultrasonography improve Zone III REBOA placement for prehospital care?
abstract: BACKGROUND
  Torso hemorrhage is the primary cause of potentially preventable mortality in trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been advocated as an adjunct to bridge patients to definitive hemorrhage control. The primary aim of this study was to assess whether contrast-enhanced ultrasonography can improve the accuracy of REBOA placement in the infrarenal aorta (Zone III).
  
  
  METHODS
  A fluoroscopy-free "enhanced" Zone III REBOA technique was developed using a porcine cadaver model. A "standard" over-the-wire Seldinger technique was used, which was enhanced with the addition of a microbubble contrast medium to inflate the balloon, observed with ultrasonography. Following this, attending- and resident-level physicians were randomized into two groups. They were taught either the enhanced with ultrasonography guidance (Group A) or the standard measuring length of catheter insertion (Group B) technique as part of a human cadaver trauma skills course. Outcomes assessed included time (seconds) from insertion to inflation, accuracy, and missed targets. All results were benchmarked against three endovascular experts.
  
  
  RESULTS
  There were 20 participants who performed REBOA with Group A (51 [31]) being significantly faster than Group B (90 [63]) (p = 0.003) and more accurate (p = 0.023) with no missed targets. Group B had five missed targets, the most common error being inflation within Zone II.
  
  
  CONCLUSIONS
  For Zone III REBOA, contrast-enhanced ultrasonography technique is faster and more accurate than the standard technique. This may have value in time-critical and austere environments. Clinical studies are now required to evaluate this approach further.
authors.affiliation: From the Department of Surgery and Cancer (M.C., J.C., M.H.W., A.D.), Imperial College London; and Department of Trauma Surgery (D.B.), Kings College Hospital NHS Foundation Trust, London; and Department of Vascular Surgery (J.J.M.), New South Glasgow University Hospital, Glasgow, United Kingdom.
authors.forename: Muzzafer
authors.initials: M
authors.lastname: Chaudery
authors.forename: James
authors.initials: J
authors.lastname: Clark
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Morrison
authors.forename: Mark H
authors.initials: MH
authors.lastname: Wilson
authors.forename: Duncan
authors.initials: D
authors.lastname: Bew
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal; D021721:Balloon Occlusion / Q000295:instrumentation / Q000379:methods*; D002102:Cadaver; D002983:Clinical Competence; D003287:Contrast Media; D004635:Emergency Medicine / Q000193:education*; D057510:Endovascular Procedures / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D010743:Phospholipids; D013459:Sulfur Hexafluoride; D013552:Swine; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride