Maximiliano Vergara

Background: The radial artery (RA) is one of the terminal branches of the brachial artery, extending along the lateral forearm, crossing the anatomical snuffbox, and contributing to the palmar arches. Anatomical variations in the RA are of great clinical relevance due to their implications in procedures such as transradial catheterization, arterial cannulation, and bypass grafting. These variants may alter the course, branching pattern, or origin of the vessel, potentially increasing procedural complexity and the risk of iatrogenic injury. In critically ill patients and in surgical or interventional settings, accurate identification of RA anatomy is essential. The objective of this study was to systematically identify and describe RA variants reported in the scientific literature and to analyze their clinical relevance. Methods: A systematic search was conducted across six electronic databases: Medline, Scopus, Web of Science, Google Scholar, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Latin American and Caribbean Literature in Health Sciences (LILACS), covering publications up to July 2025. Eligible studies included anatomical, radiological, and surgical investigations reporting RA variants. Study quality was evaluated using the Assessment of Quality in Anatomical Studies (AQUA) tool. Quantitative synthesis was performed using a random-effects model to estimate the pooled prevalence of RA variants and subgroup differences. Twenty-three studies met the inclusion criteria, and eleven were included in the meta-analysis, encompassing a total of 6320 participants. Results: Radial artery variants were categorized into three main types: variations in origin, course, and branching pattern. The pooled global prevalence of RA variants was 12% (95% CI: 6–18%), with substantial heterogeneity (I² = 97.7%). Higher prevalence was found in imaging-based studies (14%) compared with donor-based studies (12%). Sex-based subgroup analysis revealed a higher prevalence in females (18%; CI: 9–28%) compared with males (3%; CI: 3–4%), with moderate heterogeneity (I² = 61.3%). Regionally, European populations demonstrated a higher prevalence (20%) than Asian populations (11%), both showing high heterogeneity (I² > 98%). Notably, only one study from the Americas and none from Africa or Oceania were identified, representing a major geographical limitation in the available data. The findings of this study highlight the considerable variability in RA anatomy across populations. Such variations hold significant clinical importance, particularly in the context of transradial interventions, arterial cannulation, and reconstructive procedures where vascular integrity is critical. The high degree of heterogeneity observed may reflect differences in population genetics, sample size, and imaging or dissection methodologies. The limited representation of certain regions underscores the need for further anatomical and radiological studies to obtain a more comprehensive understanding of global RA variability. Preoperative or pre-procedural imaging using Doppler ultrasonography or computed tomography angiography is recommended to identify anomalous patterns and minimize iatrogenic complications. Conclusions: Radial artery variants are frequent and diverse. Their recognition is fundamental for the safety and success of invasive and surgical procedures in the upper limb. A standardized approach to vascular evaluation, particularly through preoperative imaging, is essential to improve procedural outcomes and reduce the risk of arterial injury in clinical practice.