title: Role of Pulse Pressure and Geometry of Primary Entry Tear in Acute Type B Dissection Propagation.
abstract: The hemodynamic and geometric factors leading to propagation of acute Type B dissections are poorly understood. The objective is to elucidate whether geometric and hemodynamic parameters increase the predilection for aortic dissection propagation. A pulse duplicator set-up was used on porcine aorta with a single entry tear. Mean pressures of 100 and 180 mmHg were used, with pulse pressures ranging from 40 to 200 mmHg. The propagation for varying geometric conditions (%circumference of the entry tear: 15-65%, axial length: 0.5-3.2 cm) were tested for two flap thicknesses (1/3rd and 2/3rd of the thickness of vessel wall, respectively). To assess the effect of pulse and mean pressure on flap dynamics, the %true lumen (TL) cross-sectional area of the entry tear were compared. The % circumference for propagation of thin flap (47 ± 1%) was not significantly different (p = 0.14) from thick flap (44 ± 2%). On the contrary, the axial length of propagation for thin flap (2.57 ± 0.15 cm) was significantly different (p < 0.05) from the thick flap (1.56 ± 0.10 cm). TL compression was observed during systolic phase. For a fixed geometry of entry tear (%circumference = 39 ± 2%; axial length = 1.43 ± 0.13 cm), mean pressure did not have significant (p = 0.84) effect on flap movement. Increase in pulse pressure resulted in a significant change (p = 0.02) in %TL area (52 ± 4%). The energy acting on the false lumen immediately before propagation was calculated as 75 ± 9 J/m2and was fairly uniform across different specimens. Pulse pressure had a significant effect on the flap movement in contrast to mean pressure. Hence, mitigation of pulse pressure and restriction of flap movement may be beneficial in patients with type B acute dissections.
authors: California Medical Innovations Institute, San Diego, CA, USA.
authors: Srikara V
authors: SV
authors: Peelukhana
authors: California Medical Innovations Institute, San Diego, CA, USA.|Department of General Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, China.
authors: Yanmin
authors: Y
authors: Wang
authors: 3DT holdings LLC, San Diego, CA, USA.
authors: Zachary
authors: Z
authors: Berwick
authors: Cook Medical Inc., Bloomington, IN, USA.
authors: Jarin
authors: J
authors: Kratzberg
authors: Cook Medical Inc., Bloomington, IN, USA.
authors: Joshua
authors: J
authors: Krieger
authors: Cook Medical Inc., Bloomington, IN, USA.
authors: Blayne
authors: B
authors: Roeder
authors: Rachel E
authors: RE
authors: Clough
authors: Department of Radiology, UCSD, San Diego, CA, USA.
authors: Albert
authors: A
authors: Hsiao
authors: Cook Medical Inc., Bloomington, IN, USA.
authors: Sean
authors: S
authors: Chambers
authors: California Medical Innovations Institute, San Diego, CA, USA. gkassab@calmi2.org.
authors: Ghassan S
authors: GS
authors: Kassab
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000503:physiopathology*; D001019:Aortic Rupture / Q000503:physiopathology*; D001794:Blood Pressure; D008955:Models, Cardiovascular; D011674:Pulse; D013552:Swine
keywords: Axial dissection; Bench-models; Circumferential dissection; Depth of dissection; Pulse pressure