title: Thoracic aortic pulsatility decreases during hypovolemic shock: implications for stent-graft sizing.
abstract: OBJECTIVE
  To investigate the thoracic aortic pulsatility during hypovolemic shock in an experimental porcine model.
  
  
  METHODS
  The circulating blood volume of 7 healthy Yorkshire pigs was gradually lowered until the subjects had lost 40% of their normal blood volume. Intravascular ultrasound was used to assess the aortic pulsatility in normovolemic and hypovolemic state at the level of the ascending and descending thoracic aorta.
  
  
  RESULTS
  The mean aortic pulsatility at the level of the ascending aorta decreased from 15.9% ± 7.2% (range 6.3%-25.7%) in normovolemia to 6.2% ± 2.8% (range 2.9%-10.7%, p = 0.018) in hypovolemia. At the level of the descending thoracic aorta, the mean aortic pulsatility decreased from 8.7% ± 2.8% (range 4.4%-12.2%) at baseline to 5.6% ± 2.5% (range 1.5%-9.5%, p = 0.028) in hypovolemia. The maximum mean aortic diameter, obtained in cardiac systole, was significantly smaller as well at both evaluated levels during hypovolemic shock compared with the mean diameter in normovolemia.
  
  
  CONCLUSIONS
  The thoracic aortic diameter and pulsatility decreased significantly during hypovolemic shock in this porcine model, most impressively at the level of the ascending aorta. Electrocardiographically-gated imaging may not be necessary for hypovolemic patients with acute aortic disease requiring endovascular repair because of the minimal aortic pulsatility.
authors.affiliation: Section of Vascular Surgery, Maasstad Hospital, Rotterdam, The Netherlands.
authors.forename: Frederik H W
authors.initials: FH
authors.lastname: Jonker
authors.forename: Jasper W
authors.initials: JW
authors.lastname: van Keulen
authors.forename: Felix J V
authors.initials: FJ
authors.lastname: Schlosser
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Indes
authors.forename: Frans L
authors.initials: FL
authors.lastname: Moll
authors.forename: Hence J M
authors.initials: HJ
authors.lastname: Verhagen
authors.forename: Bart E
authors.initials: BE
authors.lastname: Muhs
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D001810:Blood Volume; D004195:Disease Models, Animal; D004548:Elasticity; D057510:Endovascular Procedures / Q000295:instrumentation*; D008297:Male; D011474:Prosthesis Design; D011673:Pulsatile Flow; D012769:Shock / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015607:Stents; D013552:Swine; D018084:Ultrasonography, Interventional