Dissection Level Within Aortic Wall Layers is Associated with Propagation of Type B Aortic Dissection: A Swine Model Study

Baolei Guo; Zhihui Dong; Selene Pirola; Yifan Liu; Claudia Menichini; Xiao Yun Xu; Daqiao Guo; Weiguo Fu

doi:10.1016/j.ejvs.2019.02.026

Dissection Level Within Aortic Wall Layers is Associated with Propagation of Type B Aortic Dissection: A Swine Model Study

Eur J Vasc Endovasc Surg. 2019 Sep;58(3):415-425. doi: 10.1016/j.ejvs.2019.02.026. Epub 2019 Jul 20.

Authors

Baolei Guo¹, Zhihui Dong¹, Selene Pirola², Yifan Liu¹, Claudia Menichini², Xiao Yun Xu², Daqiao Guo³, Weiguo Fu⁴

Affiliations

¹ Department of Vascular Surgery, Zhongshan Hospital Fudan University, Shanghai, China.
² Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, UK.
³ Department of Vascular Surgery, Zhongshan Hospital Fudan University, Shanghai, China. Electronic address: guo.daqiao@zs-hospital.sh.cn.
⁴ Department of Vascular Surgery, Zhongshan Hospital Fudan University, Shanghai, China. Electronic address: fu.weiguo@zs-hospital.sh.cn.

PMID: 31337584
DOI: 10.1016/j.ejvs.2019.02.026

Abstract

Objective: Haemodynamic and geometric factors play pivotal roles in the propagation of acute type B aortic dissection (TBAD). The aim of this study was to evaluate the association between dissection level within all aortic layers and the propagation of acute TBAD in porcine aorta.

Methods: In twelve pigs, two models of TBAD were created. In model A (n = 6), the aortic wall tear was superficial and close to the intima (thin intimal flap), whereas in model B (n = 6) it was deep and close to the adventitia (thick intimal flap). Dissection propagation was evaluated using angiography or computed tomography scans, and the haemodynamic measurements were acquired using Doppler wires. Most pigs were followed up at 1, 3, 6, 12, 18, and up to 24 months; four animals were euthanised at three and six months, respectively (two from each group).

Results: Both models were successfully created. No statistical difference was observed for the median antegrade propagation distance intra-operatively between the two models (p = .092). At 24 months, the longitudinal propagation distance was significantly greater in model B than in model A (p = .016). No statistical difference in retrograde propagation was noted (p = .691). Over time, aortic wall dissection progressed most notably over the first three months in model A, whereas it continued over the first 12 months in model B. Flow velocity was significantly greater in the true lumen than in false lumen at the level of the primary tear (p = .001) and in the middle of the dissection (p = .004). The histopathological images at three and six months demonstrated the fibres were stretched linearly at the outside wall of false lumen in both models, while the depth of intimal tears developed to be superficial and similar at the distal dissection.

Conclusion: In this swine model of TBAD, a deeper intimal tear resulted in greater dissection propagation.

Keywords: Intimal tear; Propagation; Swine model; Type B aortic dissection.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Acute Disease
Animals
Aorta, Thoracic / diagnostic imaging*
Aorta, Thoracic / physiopathology
Aortic Aneurysm, Thoracic / diagnosis*
Aortic Aneurysm, Thoracic / physiopathology
Aortic Dissection / diagnosis*
Aortic Dissection / physiopathology
Blood Flow Velocity / physiology*
Computed Tomography Angiography / methods
Disease Models, Animal
Disease Progression
Female
Male
Prognosis
Severity of Illness Index
Swine
Ultrasonography, Doppler / methods