Ultrasound Velocimetry in the Abdominal Aorta Before and After Endovascular Aneurysm Repair

Summary

Rationale: An abdominal aortic aneurysm (AAA) is a common vascular disease with a high mortality in case of rupture. The underlying processes initiating aneurysmal degeneration and driving aneurysmal growth remain poorly understood. Local hemodynamics might play a key role in the pathogenesis of AAA, as it is associated with aneurysmal growth, intraluminal thrombus formation and rupture risk. Visualizing and quantifying local blood flow profiles could eventually provide more insight in the underlying mechanisms of aneurysm progression as well as identify smaller AAA with increased vulnerability or larger AAA with low risk of rupture. Consequently, this may improve risk assessment and provide patient-specific therapy guidance. Nowadays, endovascular aneurysm repair (EVAR) is the preferred treatment modality in most patients with an infrarenal AAA. However, EVAR is associated with a relatively high reintervention rate. It is hypothesized that the placement of a stent graft may alter local hemodynamics and subsequent recirculations or flow stagnations promote the onset of thrombosis or micro-emboli. These unfavourable flow conditions might be related to various complications after EVAR, such as limb occlusion, renal dysfunction, and the persistence of type II endoleaks. Visualizing local blood flow profiles after EVAR might provide insight in these (un)favourable conditions. In vivo blood flow quantification is a great challenge, particularly in the abdomen. Advanced ultrasound based techniques, incorporating ultrasound contrast agents and plane wave imaging, proved to be feasible in quantifying aortoiliac blood flow patterns in healthy volunteers.

Objective: The aim of this study is to determine the feasibility of ultrafast contrast-enhanced ultrasound particle image velocimetry (echoPIV) measurements to quantify spatiotemporal blood flow velocity profiles in the abdominal aorta of AAA patients before and after endovascular repair.

Secondary objectives are to determine the correlation between echoPIV and phase-contrast MRI (PC MRI) based measurements to ultimately validate the spatiotemporal velocity profiles obtained with echoPIV. Furthermore, changes in blood flow velocity profiles after placement of a stent graft will be evaluated.

Conditions

• Abdominal Aortic Aneurysm

Interventions

DIAGNOSTIC_TEST

EchoPIV

All patients will undergo an echoPIV measurement 6 to 8 weeks before and 6 to 8 weeks after endovascular aneurysm repair. These measurements will take place at the Vascular Center of Rijnstate Hospital. A venous cannula will be inserted to enable contrast administration. Ultrasound data will be collected at the caudal renal artery, infrarenal neck, aneurysm sac and both iliac arteries.

DIAGNOSTIC_TEST

4D flow MRI

A 4D phase-contrast magnetic resonance imaging (4D flow MRI) scan of the abdominal aorta will be obtained 6 to 8 weeks before and 6 to 8 weeks after endovascular aneurysm repair.

Sponsors & Collaborators

• University of Twente

  collaborator OTHER

• Rijnstate Hospital

  lead OTHER

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-07-06

Primary Completion

2023-08-22

Completion

2023-08-22

Countries

• Netherlands

Study Locations