Abstract

Background: Differences in renal arterial anatomy, especially accessory renal arteries and early prehilar bifurcation are normal and have significant consequences in kidney transplantation, nephron-sparing surgery and minimally invasive urological surgery. This systematic review assessed the frequency of these anatomical variants and their clinical implication. Procedures: The review followed PRISMA 2020 guidelines and the Evidence-Based Anatomy framework. Cadaveric and angiographic studies published between 2020 and 2025 reporting accessory renal arteries were included. Pooled prevalence was estimated using a random-effects model with Freeman-Tukey double arcsine transformation, and heterogeneity was assessed using the I² statistic. Findings: Eight studies involving 4,617 participants met the inclusion criteria, of whom 1,257 had at least one accessory renal artery. The pooled prevalence of accessory renal arteries was 22.9% (95% CI: 15.5-31.2), with high heterogeneity (I² = 96.0%). Most accessory arteries originated from the abdominal aorta and supplied the lower pole or renal hilum. They were generally solitary and occurred slightly more frequently on the left side and in males. Early prehilar branching was reported in 5-17% of subjects. Although kidneys with multiple renal arteries required longer reconstruction and ischemia times, recent studies demonstrated comparable graft function, patient survival, and transplant outcomes to kidneys with a single renal artery. Conclusion: Accessory renal arteries are normal anatomical variants, which must be identified by preoperative CT angiography to optimize surgical planning and donor selection.

Keywords: Renal artery, Accessory renal artery, Anatomical variation, Kidney transplantation, Partial nephrectomy, CT angiography, Living donor