Cine MRI Assessment of Aortic Aneurysm Dynamics before and after Endovascular Repair

Abstract

After EVAR, increased longitudinal translation of both the aneurysm and stent-graft was observed, indicating downward pulling forces at the proximal fixation site. Secondly, increased bending was seen at the site of maximal angulation, which implies a risk of metal fatigue and fabric damage at sites of stent-graft angulation.

Dynamic geometry and wall thickness of the aortic neck of abdominal aortic aneurysms with intravascular ultrasonography

“…[1][2][3][4][5][6] In fact, dynamic MRA has demonstrated that significant aortic neck area changes occur during the cardiac cycle both before and after EVAR. [15][16][17][18][19] Of note, both CTA and MRA have some limitations, including renal failure and radiation exposure with CTA and claustrophobia and nephrogenic fibrosing dermopathy in patients with chronic renal insufficiency with MRA. In addition, not all endografts can be evaluated with MRA.…”

Roentgen Stereophotogrammetric Analysis: An Accurate Tool to Assess Stent-Graft Migration

“…Based on the protocol published by Murphy et al, 16 a 2-mm margin of error has been reported by Hodgson et al 17 in an experimental static model that eliminated any pulsatile axial movement of the aorta relative to the spine. Flora et al 18 measured a pulsatile movement up to 1 mm in just 4 patients, 18 while Vos et al 14 reported craniocaudal movement of up to 1.99 mm in 7 patients, 14 indicating that a wider range of movement is likely. The measurement error in a static situation versus the pulsatile motion of the aorta-stent-graft complex could significantly impair the accuracy of stent-graft migration assessment with plain radiography.…”

“…Pulsatile changes in the aorta-stent-graft complex 14,15 will result in minimal measurement error due to this short acquisition time.…”

In-Vivo Imaging of Changes in Abdominal Aortic Aneurysm Thrombus Volume During the Cardiac Cycle

“…Previous studies using dynamic CTA and magnetic resonance angiography have shown 2D changes in AAA geometry during the cardiac cycle and addressed the possible impact of dynamic imaging on patient selection for endovascular aneurysm repair. [21][22][23] The current study focused on the potential of dynamic CTA to quantify 3D changes in thrombus volume (compressibility) and the possible impact on aneurysm biomechanics. This required a novel approach using dynamic CTA and advanced 3D volumetric analysis.…”