Abdominal vascular compression syndromes are rare but clinically significant conditions resulting from the external compression of vascular structures, leading to altered haemodynamics and potential complications. This presentation provides an overview of the pathophysiology and ultrasound appearances of four key syndromes: left iliac compression syndrome (May-Thurner syndrome), median arcuate ligament syndrome (MALS), left renal vein compression syndrome (Nutcracker syndrome), and superior mesenteric artery (SMA) syndrome.

Through a review of the pathophysiology and ultrasound imaging, this presentation aims to enhance the recognition and diagnostic confidence of these syndromes.

References
• Biank, V. & Werlin, S. (2006). Superior mesenteric artery syndrome in children: A 20-year experience. Journal of Pediatric Gastroenterology and Nutrition, 42(5), pp.522-525.
• He, Y., Wu, Z., Chen, S., Tian, L., Li, D. & Li, M. (2014). Nutcracker syndrome—how well do we know it? Annals of Vascular Surgery, 28(6), pp.1550-1559.
• Poyyamoli, S., Mehta, P., Cherian, M., Anand, R. R., Patil, S. B., Kalva, S., & Salazar, G. (2021). May-Thurner syndrome. Cardiovascular diagnosis and therapy, 11(5), 1104–1111.
• Goodall R, Langridge B, Onida S, Ellis M, Lane T, Davies AH. Median arcuate ligament syndrome. J Vasc Surg. 2020 Jun;71(6):2170-2176.

Cardiac disease can cause changes to the normal abdominal waveforms. What should we be looking out for, as general Sonographers, to alert us that our patient possibly has underlying cardiac disease.

Introduction: Colour Doppler and power Doppler are both essential techniques used to assess blood flow in ultrasound imaging. Both provide real-time information and are invaluable in vascular studies, evaluation of organ perfusion and in characterisation of pathology. They each offer unique advantages which should be carefully considered before use to enhance diagnosis depending on the clinical scenario.
Method: Colour and power Doppler will be explained and compared using the “what, why, where, when and how” method of questioning. A simple and systematic approach will be presented for optimisation of Doppler operative settings.
Results: Colour Doppler effectively identifies the velocity and direction blood flow in vessels. It is expressly valuable for assessing larger vessels, detecting obstructions, stenosis and aneurysms and monitoring the effectiveness of interventions. Power Doppler demonstrates superior sensitivity and is valuable for detecting subtle blood flow in small vessels or low-flow regions. Use of power Doppler is ideal when information about perfusion is required and is more effective in identifying hyperaemia in inflammatory conditions and evaluating tumour vascularity. Power Doppler lacks directional information.
Conclusion: Colour Doppler is best for evaluating high-flow, directional vessels, while power Doppler excels in assessing slow or low-flow vascularity and inflammation. Selecting the appropriate mode and systematic optimisation of the Doppler settings will result in high quality and thorough ultrasound examinations.
Take home message: Guided by clinical indications, sonographers should leverage colour and power Doppler selectively to provide comprehensive vascular assessments and maximise diagnostic usefulness and efficiency.

Introduction: Endovascular Aneurysm Repair (EVAR) is a common procedure to treat aortic aneurysms. Ultrasound monitoring for endoleaks is common practice and often involves assessing for endoleaks via indirect methods such as interval growth of aneurysm sac size. The use of colour Doppler can be problematic for endoleak evaluation due to motion artefact and computed tomography (CT) has often been the modality of choice for further assessment. However, CT is only a snapshot in time and contrast pooling can often indirectly diagnose endoleak type.
Method: Patients who underwent an EVAR repair that showed sac size growth were referred for Contrast Enhanced Ultrasound (CEUS). Majority of these patients have had previous CT scans which were inconclusive, and CEUS was used to better define type of endoleak.
Results: Vast majority of patients who had an inconclusive CT scan had a conclusive diagnosis of type of endoleak via CEUS. Type 2 endoleaks were the most common diagnosis on CEUS due to the delayed filling of contrast into the aneurysm sac. CEUS allowed problem solving of uncertain diagnosis on CT scans.
Conclusion: Contrast Enhanced Ultrasound allows for real time diagnosis of EVAR leaks without the need for radiation or iodinated nephrotoxic contrast. It allows for more definitive diagnosis and should be used in cases where there has been an inconclusive colour Doppler or contrast CT.

Ultrasound is a useful tool in identifying and monitoring patients with non-aortic abdominal aneurysms. It can provide an accurate location, and measurements of the aneurysm's size, along with the aneurysm morphology. This information is useful for vascular surgeons when assessing these patients as it will determine whether they can be treated conservatively or require surgical intervention.

This talk will demonstrate a wide variety of non-aortic abdominal aneurysm case studies, providing you with the knowledge to find, examine, and document all the information the vascular surgeon will need when reviewing these patients.