Prediction of Right Renal Artery Take-off Level in Relation to Aortoiliac Bifurcation: A Computed Tomography Study

Abstract

Introduction: Several anatomical landmarks are used to approximately assess the renal artery (RA) take-off level. We aimed to evaluate the relationship between aortoiliac bifurcation (AIB) and the RA take-off levels. Patients and Methods: Overall, 113 patients (71 male; mean age, 42 ± 18 years) without a history of vascular disease and who had undergone cervico-thoraco-abdominal computed tomography (CT) scan were retrospectively studied. The corresponding spinal levels of AIB and the right RA take-off level were craniocaudally set at levels 1-4 (for AIB, L3, L3/4 intervertebral disc, L4, and distal to L4, respectively, and for right RA, T12/L1 intervertebral disc, L1, L1/2 intervertebral disc, and L2, respectively). The relationship between two levels was analyzed by correlation analysis. Results: The most prevalent level for AIB was L4 (level 3) and for right RA was L1 (level 2). The prevalences of levels 1-4 for right RA were 10.6%, 56.6%, 17.7% and 15%, respectively, and those for AIB were 6.2%, 18.6%, 47.8%, and 27.4%, respectively. There was a positive significant correlation between the levels of AIB and right RA [correlation coefficient (CC), 0.7; p< 0.001]. This correlation was slightly less in women (CC, 0.59; p< 0.001) and more in men (CC, 0.74; p< 0.001). The patients were divided into the following two groups according to their ages: young (< 60 years) and old (≥ 60 years). There was a similar positive significant correlation between the age groups (CC, 0.71 and 0.65, respectively; p< 0.001). Conclusion: The spinal level of right RA is positively and significantly correlated with the AIB level. Therefore, AIB can be used as a landmark for approximation of RA take-off level.