Skip to main content
OpenTrials
Completed

NCT Number: NCT01907386

Abdominal Aortic Aneurysm Follow-up After Endovascular Repair by Non-invasive Vascular Elastography

Abdominal aortic aneurysm (AAA) is an abnormal dilatation of the aorta in the abdomen secondary to hypertension and atherosclerosis. Surgical treatment of AAA is increasingly being replaced by endovascular aneurysm repair (EVAR) using stent-grafts (SGs). However, the efficacy of this less invasive approach is often jeopardized by the incidence of persistent flow within the aneurysm, called endoleaks leading to aneurysm rupture if not properly detected and treated. Hence, a life long annual CT-scan surveillance is required increasing the cost of EVAR, exposing the patient to ionizing radiation and nephrotoxic contrast agent. The goal of this project is to adapt and test a new ultrasound technology called ultrasound elastography to improve patient follow-up after EVAR and ultimately avoid the use of CT-scans. This technique measures the deformation of the tissue secondary to blood pressure variation (quasi-static elastography) or to a shear wave generated by the ultrasound probe (dynamic elastography). The investigators will optimize 2 approaches to generate elastic maps of the AAA. One approach will be a quasi-static elastography (QSE-LSME) technique developed by our team giving an estimation of the deformation (strain) of the different components of the AAA by the blood pressure. The second is a dynamic elastography (SSWI) technique that will provide information on the elastic property of the AAA components.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Aortic Aneurysm Abdominal Aneurysm Aortic Aneurysm Aortic Aneurysm, Abdominal Aortic Diseases Cardiovascular Diseases Endoleak Endovascular Aneurysm Repair (EVAR) Hemorrhage Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Postoperative Hemorrhage Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Centre Hospitalier de l'Université de Montréal (CHUM)

Montreal, Quebec, H2L 4M1, Canada

About this study

Experimental protocol: Optimization and validation of these 2 techniques will be completed in 3 experimental phases:

  • Preclinical validation: Abdominal aortic aneurysm and EVAR without endoleak (n=6), with a type I (n=6) and a type II (n=6) endoleak will be created in 18 mongrel dogs. QSE-LSME and SSWI acquisitions will be acquired before SG insertion and at 48H, 1, 3 months and at sacrifice at 6 months. The 2 techniques will be optimized to generate strain (QSE-LSME) and elasticity (SSWI) measurements of the simulated thrombus and vessel wall. CT-scan with prospective gating will be acquired on the AAA at least 6 different cardiac phases then segmented to allow 2D/3D registration of CT and elastographic acquisitions. Strain (QSE-LSME) and elasticity (SSWI) measurements of sac thrombus and vessel wall will be compared in the three experimental groups and correlated to sac pressure measurements, CT segmentation of sac components and pathologic evaluation.
  • Clinical feasibility, reproducibility and correlation with CT-angiography. From our EVAR database, 3 groups of 15 patients will be selected based on clinical and CT-angiography evolution. Group 1 will include patients without endoleak and AAA volume decrease of more than 20% following EVAR, group 2 patients without endoleak and no more than 10% sac volume variation and group 3 patients with endoleak or endotension and more than 20% sac volume increase. Ultrasound B-mode RF acquisitions with QSE-LSME and SSWI techniques will be acquired by two independent investigators. We will compare strain values of the different AAA components in the three groups. Thresholds will be tested to detect endoleak. Then strain values will be correlated with diameter, volume and stretch index variation between baseline and contemporary CT scans.
  • Prospective study validation of strain elasticity thresholds for endoleak detection and characterization of thrombus organization. The goal of this second clinical feasibility study is to collect longitudinal strain and elasticity measurements in the early post EVAR period (before one-year). We will include 15 patients with AAA scheduled for EVAR. These patients will have a baseline CT and baseline QSE-LSME and SSWI examination. Doppler ultrasound with QSE-LSME and SSWI examinations will then be performed at 3 and 12 months. The variation of strain and elastic values over time frames will be analyzed and correlated volume progression and endoleak occurrence on CT scans.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients with at least one-year follow-up after EVAR
  • Willingness to comply with study follow-up requirements
  • Written informed consent

Exclusion criteria

  • Patients not clinically followed by CT-scans

Treatment and study plan

QSE-LSME - SSWI Ultrasound

Other

Doppler ultrasound (DUS) and elastographic examinations will be performed using a single probe (6-1 MHz, Super Curved, Vermon, Tours, France) with the clinical Aixplorer system (Supersonic Imagine, Aix-en-Provence, France), a new generation ultrasound scanner providing an outstanding B-mode and color-Doppler image quality, allowing exportation of RF images for QSE-LSME acquisition and integrating the shear wave elastography (SSWI) mode.

Primary outcomes

  1. QSE-LSME

    Time frame: Day 0: When the elastographic examinations (QSE-LSME, SSWI) and CT-scan will be completed

    We will compare strain values of the different AAA components in the three groups Then, we will test the best combination of strain criteria defined in the preclinical optimization and validation phase among three groups to evaluate if we can define a threshold to discriminate the 3 groups.

  2. SSWI

    Time frame: Day 0: When the elastographic examinations (QSE-LSME, SSWI) and CT-scan will be completed

    Elasticity values of the aortic wall and thrombus in systolic and diastolic phase will be compared in the 3 groups

Sponsors and collaborators

Lead sponsor

Centre hospitalier de l'Université de Montréal (CHUM)

Other

Collaborators

  • Canadian Institutes of Health Research (CIHR)

Registry information

Acronym: AAA-Elasto

Important dates

Study start
2014
Primary completion
2017
Study completion
2018
First posted
Jul 25, 2013
Registry last updated
Jul 20, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.