Retearing of type B blind cystic aortic dissection: computational fluid dynamics analysis

Area of Science:

• Cardiovascular Medicine
• Vascular Surgery
• Biomedical Engineering

Background:

• Aortic dissection (AD) is a critical vascular condition with insufficient research on type B blind cystic AD.
• This specific AD type features a single proximal intimal tear and a blind-ended false lumen (FL).

Purpose of the Study:

• To identify hemodynamic indicators of re-tearing in type B blind cystic AD.
• To pinpoint high-risk areas for FL rupture in these patients.

Main Methods:

• Analysis of pathological characteristics from 4 fatal type B blind cystic AD cases.
• Computational modeling using imaging data from 5 type B AD patients (1 deceased, 4 with multiple intimal tears).
• Comparison of pressure, velocity, time-averaged wall shear stress (TAWSS), and relative residence time (RRT) between models.

Main Results:

• Type B blind cystic AD patients exhibit high FL pressure, low TAWSS, and high RRT.
• Elevated TAWSS observed in the FL adjacent to the proximal intimal tear.
• Significant changes in true lumen (TL) blood flow velocity and pressure difference, exacerbated by aortic curvature.

Conclusions:

• High pressure is a primary driver of FL rupture in type B blind cystic AD.
• The FL region near the proximal intimal tear is a critical high-risk rupture zone.
• Blood flow alterations and pressure differentials may induce distal intimal re-tears; aortic tortuosity influences pressure changes.