Foundational Image Analyses for Ultrasonographic Screening of Abdominal Aortic Aneurysm

Objectives: With improved surgical outcomes for non-ruptured abdominal aortic aneurysm (AAA), the primary objective has shifted toward the detection of asymptomatic AAA. Since ultrasonographic visualization from the anterior abdominal wall is often obstructed by intestinal gas, utilizing additional bilateral posterior approaches via the retroperitoneal tissue may be beneficial. This study investigates the feasibility of assessment using three approaches through computed tomography (CT) data analyses. Methods: The study included 27 surgical patients with AAA (AAA group) and 37 patients with other atherosclerotic diseases (non-AAA group). CT data were analyzed to locate the infrarenal aorta relative to the navel, availability of acoustic window, depth of the aorta, and assessment of aneurysmal aorta using three approaches. Results: The "AAA area" for ultrasonographic screening may be set at 0-4 cm above the navel. An acoustic window was unavailable in 8.1% of AAA cases and 7.4% of non-AAA cases in the anterior approach; however, it was available in the posterior approach. Although the depth of the aorta was greater in obese patients, it remained within 20 cm. Conclusion: Ultrasonographic screening is feasible by incorporating posterior approaches in cases where anterior visualization is difficult, enhancing the detection of asymptomatic AAA.