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Aberrant renal vessels crossing the ureter and the ureteropelvic junction: A retrospective computed tomography-based analysis of non-obstructed population

Year: 2026

Type: article

Abstract: BACKGROUND: Crossing renal vessels are recognized as potential extrinsic contributors to ureteropelvic junction obstruction; however, their prevalence and morphological characteristics in adults without urinary tract obstruction remain incompletely characterized. AIM: To determine the prevalence, vascular composition, morphological patterns, and spatial relationship of renal vessels crossing the ureteropelvic junction (UPJ) or proximal ureter using contrast-enhanced computed tomography (CT). METHODS: A retrospective review of 197 adult patients (394 kidneys) with normal urological anatomy who underwent contrast-enhanced abdominal CT was conducted. Multiplanar and three-dimensional reconstructions were evaluated to document crossing vessel prevalence, etiology (arterial, venous, or combined), specific anatomical variations (early bifurcations or accessory vessels), spatial orientation (anterior/posterior), and exact intersection distance to the ureteropelvic. RESULTS: = 0.007). Presentations were unilateral in 69.8% and bilateral in 30.2% of cases. Arterial anomalies predominated (64.3%), mostly due to early main renal artery bifurcations, while combined arterio-venous crossings occurred in 25% of cases. The spatial orientation was overwhelmingly anterior (98.2%). Direct UPJ intersection (0 mm) was observed in 37.5% of cases, whereas distal ureteral intersections occurred at a mean distance of 16.2 ± 4.5 mm from the junction. CONCLUSION: Renal vessels crossing the UPJ or proximal ureter are not uncommon incidental anatomical findings on contrast-enhanced CT in adults without obstruction. Their baseline prevalence in an unobstructed cohort highlights that crossing vessels can exist without concurrent obstruction. Contrast-enhanced CT provides detailed anatomical mapping of the vascular course, which may support preoperative planning and help mitigate the risk of inadvertent vascular injury when surgical intervention is indicated. Nevertheless, functional assessment remains necessary when clinically significant obstruction is suspected.

Source: World Journal of Radiology

DOI: 10.4329/wjr.127348