Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 0 0 2026 04 21 11880 11880 Babak Eslami Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. AND Anesthesia, Critical Care and Pain Management Research Center, Tehran University of Medical Sciences, Tehran, Iran. Alireza Montaseri Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Farhood Abassalipour Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Maryam Parnian Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Asghar Hajipour Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Maziar Maghsoudloo Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Mehrshad Namazi Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Kaveh Hedayati Emami Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Manouchehr Nasrolllahzadeh Saravi School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2025 11 08 2025 12 27 Establishing reliable intravenous access in patients with difficult peripheral veins is a common challenge in perioperative care. In such cases, central venous catheterization (CVC) is often used despite its invasive nature and associated risks. For short elective procedures, this may be excessive. Ultrasound-guided peripheral vein catheterization (US-PVC) has emerged as a safer, less invasive alternative that improves success rates. However, limited evidence exists comparing different anatomical sites for US-PVC in this population. This study aims to compare the efficacy and complication rates of ultrasound-guided IV access in the antecubital versus saphenous regions in adult surgical patients with difficult venous access. This single-center, parallel-group, randomized clinical trial was conducted on adult patients undergoing elective surgery with difficult peripheral venous access. Patients were randomized to receive US-guided catheterization in either the antecubital (Group A) or saphenous (Group B) region. All procedures were performed by an anesthesiologist experienced in ultrasound-guided vascular access. Primary outcomes included first-attempt success rate and catheterization time; secondary outcomes included complication rates and patient-reported satisfaction. Follow-up assessments were conducted at 24 hours and 72 hours post-procedure. The saphenous group demonstrated significantly higher first-attempt success rates (53.1% vs. 44.9%, P=0.04) and greater catheter durability (89.8% vs. 75.6%, P=0.03). However, this group also reported significantly more procedural pain based on VAS scores (4.94 vs. 2.24, P<0.001), as well as greater increases in mean arterial pressure and heart rate. Although complication rates such as hematoma and thrombophlebitis were slightly higher in the antecubital group, the differences were not statistically significant. Patient satisfaction was significantly higher in the saphenous group (95.8% vs. 77.6%, P=0.001), while staff satisfaction did not differ meaningfully between groups. Ultrasound-guided IV catheterization in both antecubital and saphenous regions is effective in patients with difficult venous access. The saphenous site offers higher first-attempt success and catheter longevity but is associated with more discomfort. These findings may aid anesthesiologists in selecting optimal access sites based on clinical needs and patient tolerance. This study was approved by the Tehran University of Medical Sciences Ethics Committee (Ethics Code: IR.TUMS.IKHC.REC.1402.418, IRCT Id: IRCT20230130057273N2). https://acta.tums.ac.ir/index.php/acta/article/view/11880 https://acta.tums.ac.ir/index.php/acta/article/download/11880/6027