title: Vibrometry: a novel noninvasive application of ultrasonographic physics to estimate wall stress in native aneurysms.
abstract: Our objective was to test vibrometry as a means to measure changes in aneurysm sac pressure in an in vitro aneurysm model. Explanted porcine abdominal aortas and nitrile rubber tubes were used to model an aneurysm sac. An ultrasound beam was used to vibrate the surface of the aneurysm model. The motion generated on the surface was detected either by reflected laser light or by a second ultrasound probe. This was recorded at different aneurysm pressures. The phase of the propagating wave was measured to assess changes in velocity and to see if there was a correlation with aneurysm pressure. The cumulative phase shift detected by laser or Doppler correlated well with increasing hydrostatic pressure in both the rubber and the porcine aorta model. The square of the mean pressure correlated well with the cumulative phase shift when dynamic pressure was generated by a pump. However, the pulse pressure was poorly correlated with the cumulative phase shift. Noninvasive measurement of changes in aortic aneurysm sac tension is feasible in an in vitro setting using the concept of vibrometry. This could potentially be used to noninvasively detect wall stress in native aneurysms and endotension after endovascular aneurysm repair (EVAR) and to predict the risk of rupture.
authors.affiliation: Department of Vascular Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Gautam
authors.initials: G
authors.lastname: Agarwal
authors.forename: Geza
authors.initials: G
authors.lastname: Mozes
authors.forename: Randall R
authors.initials: RR
authors.lastname: Kinnick
authors.forename: Peter
authors.initials: P
authors.lastname: Gloviczki
authors.forename: Russell E
authors.initials: RE
authors.lastname: Bruhnke
authors.forename: Michele
authors.initials: M
authors.lastname: Carmo
authors.forename: Tanya L
authors.initials: TL
authors.lastname: Hoskin
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Bennett
authors.forename: James L
authors.initials: JL
authors.lastname: Greenleaf
mesh_terms: D000783:Aneurysm / Q000000981:diagnostic imaging*; D000818:Animals; D001011:Aorta / Q000000981:diagnostic imaging; D013677:Medical Laboratory Science / Q000295:instrumentation* / Q000379:methods*; D009573:Nitrites; D012408:Rubber; D013314:Stress, Mechanical; D013552:Swine; D014463:Ultrasonography; D014732:Vibration
chemical_list: D009573:Nitrites; D012408:Rubber