TransThoracic Ultrasound for Descending Aortic Aneurysms

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.

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.