Intraluminal morphometric analysis of abdominal aortic branches: spatial landmarks for interventional radiology and colorectal surgery.

PURPOSE: Precise knowledge of the spatial relationships of abdominal aortic branches is essential for safe colorectal surgery and interventional radiologic (IR) procedures. While most studies describe these vessels from an external or imaging perspective, intraluminal morphometric data relevant to catheter-based navigation remain limited. This study aimed to evaluate the positional relationships and morphometry of major abdominal aortic branches from an intravascular perspective. METHODS: Intravascular dissections were performed in 19 formalin-embalmed cadavers (12 males, 7 females; age range 50-96 years) after exclusion of one specimen with para-aortic pathology. Morphometric parameters of the celiac trunk (CT), superior mesenteric artery (SMA), inferior mesenteric artery (IMA), and left renal artery (LtRA) were measured relative to the aortic bifurcation (BA). Longitudinal, linear, and transverse distances, vessel diameters, and branching angles were obtained using calibrated instruments and analyzed statistically. RESULTS: The longitudinal distance between the CT and SMA was 19.48 ± 4.41 mm. The angle between the transverse aortic axis and the SMA-IMA trajectory was 89.03 ± 3.59°, demonstrating relative angular consistency. A strong positive correlation was identified between LtRA-CT and LtRA-SMA longitudinal distances (r = 0.846, p = 0.001). While the CT-SMA relationship was relatively stable, the SMA-IMA interval exhibited greater variability (p = 0.05). CONCLUSION: This morphometric study of the lumen provides quantitative spatial data of the major abdominal aortic branches. These findings suggest that the LtRA is a reliable intraluminal landmark and provide further evidence for stable angular relationships between mesenteric vessels. These findings might be helpful for vascular navigation, but their clinical use requires further validation in prospective studies.