TransThoracic Ultrasound for Descending Aortic Aneurysms

Official title

Feasibility, Accuracy and Reproducibility of Ultrasound in Aneurysms of the Descending Thoracic Aorta

Overview

The goal of this observational study is to assess the applicability of non-invasive ultrasound in aneurysms of the descending thoracic aorta. The main question it aims to answer is: What is the feasibility of Ultrasound to visualise the Descending Thoracic Aorta, and can this imaging modality accurately measure the maximum size of aneurysms and residual sacs with acceptable reproducibility? Participants are having their diagnosis confirmed or excluded by conventional imaging techniques (CT scans). Participants receive exactly the same standard of care regardless of their participation. The study offers an additional ultrasound scan, and the results will be compared with previous imaging.

Detailed description

Aneurysms of the aortic artery are a significant public health issue. The number of newly diagnosed aneurysms of the thoracic aorta is on the rise, and aneurysm rupture is a catastrophic event associated with high mortality rates. The most proximal sections of the aorta (ascending and the aortic arch) are routinely scanned by echocardiography practitioners. The abdominal aorta is also easily visualised on transabdominal ultrasound, and there is a screening programme in the UK that is highly cost-effective and reduced the aneurysm-related number of deaths. However, the portion of the aorta in the chest (descending thoracic aorta) is not routinely assessed by ultrasound practitioners.

The diagnosis of descending thoracic aneurysms relies mostly on imaging techniques that use ionising radiation. In addition, these techniques are expensive and may not be widely available in some regions. In contrast, ultrasound is a non-invasive technique that allows visualisation of most parts of the body. Ultrasound machine suppliers have invested in better systems and transducers over the years and visualisation of the descending thoracic aorta may now be possible.

The main aims of this study are to assess the feasibility (Part 1), accuracy (Part 2) and reproducibility (Part 3) ultrasound in the diagnosis and monitoring of descending thoracic aortic aneurysms. Participants will be recruited from the vascular lab and outpatient clinics, and diameters of the descending thoracic aorta will be measured with non-invasive ultrasound. Data obtained from study measurements will be compared with computed tomography scans that patients had as part of their standard of care.

If the feasibility, accuracy and reproducibility of Ultrasound are clearly demonstrated, routine ultrasound scans of the descending thoracic aorta may be suggested.

Primary outcome measures

• Part 1 - Feasibility - Proportion of participants with successful ultrasound measurement of the diameter of the descending thoracic aorta [Time frame: Day 1 - At the single ultrasound study visit.]
• Part 1 - Feasibility - Length of the descending thoracic aorta by Ultrasound [Time frame: Day 1 - At the single ultrasound study visit.]
• Part 1 - Feasibility - Ultrasound Quality Score [Time frame: Day 1 - At the single ultrasound study visit.]
• Part 2 - Accuracy - Comparision between Transthoracic Ultrasound and CT [Time frame: Day 1 - At the single ultrasound study visit.]
• Part 3 - Reproducibility - Intraclass correlation coefficient [Time frame: Day 1 - At the single ultrasound study visit.]

Secondary outcome measures (3)

• Part 1 - Feasibility - Factors limiting visualisation of the Descending Thoracic Aorta [Time frame: Day 1 - At the single ultrasound study visit.]
• Part 1 - Feasibility - Duration of Ultrasound Examination [Time frame: Day 1 - At the single ultrasound study visit.]
• Part 1 - Feasibility - Patient Feedback Questionnaire [Time frame: Day 1 - At the single ultrasound study visit.]

Eligibility criteria

Inclusion criteria

• Patients with diagnosed AAA or other vascular condition attending the vascular scanning department for routine ultrasound and confirmed healthy DTA (Control group).
• Patients with known DTAA (including Type B dissection) or patients who had TEVAR previously (Case group).
• Patients who have had CT as part of their standard of care.
• Patients able to tolerate the scan (Lying in supine position).
• Adults aged 18 or over.
• Willing to provide consent.

Exclusion criteria

• Patient under 18 years of age.
• Previous thoracic surgery or body deformity (severe kyphosis, scoliosis, pleural effusion or chest wall trauma).
• Patients without previous imaging of the thoracic aorta.
• Life expectancy <2 years.
• Pregnant Women.
• Patients unwilling to provide consent or unable to comply with study requirements.
• Patients too frail to travel to routine outpatient appointments.
• Inability to attend the appointment due to time constraints or other commitments.
• Although rare, ultrasound contraindications as described in the scanning protocol are also exclusion criteria.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Observational model

Cohort

Study locations

United Kingdom · 1 center

• Imperial College Healthcare NHS Trust - St Mary's Hospital — London

Identifiers

NCT: NCT07752654 · 199470 · IRAS Project ID: 365629

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗