Your browser doesn't support javascript.
loading
Endograft exclusion of the false lumen restores local hemodynamics in a model of type B aortic dissection.
Birjiniuk, Joav; Oshinski, John N; Ku, David N; Veeraswamy, Ravi K.
Afiliação
  • Birjiniuk J; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga. Electronic address: joav.birjiniuk@nyulangone.org.
  • Oshinski JN; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga; Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga.
  • Ku DN; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Ga; Division of Vascular Surgery, Joseph B. Whitehead Department of Surgery, Emory University School of Medicine, Atlanta, Ga.
  • Veeraswamy RK; Division of Vascular Surgery, Department of Surgery, Medical University of South Carolina, Charleston, SC.
J Vasc Surg ; 71(6): 2108-2118, 2020 06.
Article em En | MEDLINE | ID: mdl-32446515
ABSTRACT

OBJECTIVE:

Endovascular intervention in uncomplicated type B dissection has not been shown conclusively to confer benefit on patients. The hemodynamic effect of primary entry tear coverage is not known. Endovascular stent grafts were deployed in a model of aortic dissection with multiple fenestrations to study these effects. It is hypothesized that endograft deployment will lead to restoration of parabolic true lumen flow as well as elimination of false lumen flow and transluminal jets and vortices locally while maintaining distal false lumen canalization.

METHODS:

Thoracic stent grafts were placed in silicone models of aortic dissection with a compliant and mobile intimal flap and installed in a flow loop. Pulsatile fluid flow was established with a custom positive displacement pump, and the models were imaged by four-dimensional flow magnetic resonance imaging. Full flow fields were acquired in the models, and velocities were extracted to calculate flow rates, reverse flow indices, and oscillatory shear index, the last two of which are measures of stagnant and disturbed flows.

RESULTS:

Complete obliteration of the false lumen was achieved in grafted aorta, with normal parabolic flow profiles in the true lumen (maximal velocity, 30.4 ± 8.4 cm/s). A blind false lumen pouch was created distal to this with low-velocity (5.8 ± 2.7 cm/s) and highly reversed (27.9% ± 13.9% reverse flow index) flows. In distal free false lumen segments, flows were comparable to ungrafted conditions with maximal velocities on the order of 7.0 ± 2.1 cm/s. Visualization studies revealed forward flow in these regions with left-handed vortices from true to false lumen. Shear calculations in free false lumen regions demonstrated reduced oscillatory shear index.

CONCLUSIONS:

Per the initial hypothesis, endovascular grafting improved true lumen hemodynamics in the grafted region. Just distally, a prothrombotic flow regimen was noted in the false lumen, yet free false lumen distal to this remained canalized. Clinically, this suggests a need for advancing endovascular intervention beyond sole entry tear coverage to prevent further false lumen canalization through uncovered fenestrations.
Assuntos
Palavras-chave

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Prótese Vascular / Stents / Aneurisma da Aorta Torácica / Implante de Prótese Vascular / Hemodinâmica / Dissecção Aórtica Tipo de estudo: Prognostic_studies Limite: Adult / Female / Humans Idioma: En Revista: J Vasc Surg Assunto da revista: ANGIOLOGIA Ano de publicação: 2020 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Prótese Vascular / Stents / Aneurisma da Aorta Torácica / Implante de Prótese Vascular / Hemodinâmica / Dissecção Aórtica Tipo de estudo: Prognostic_studies Limite: Adult / Female / Humans Idioma: En Revista: J Vasc Surg Assunto da revista: ANGIOLOGIA Ano de publicação: 2020 Tipo de documento: Article