A four-step protocol to overcome loops/tortuosity during transradial coronary interventions: introducing the ‘’Serpentine’’ technique

The radial artery access is frequently used in coronary interventions. However, anatomical variations, such as loops, can pose significant challenges, leading to an increased number of access site crossovers. This study presents a four-step protocol introducing the “Serpentine” technique, a novel approach based on specific maneuvers using the Tiger-II catheter to navigate radial artery loops. This was based on a prospective registry of patients who underwent transradial coronary angiography at our tertiary hospital between 2020 and 2022 and our predefined four-step protocol was applied. Procedural success was defined as the completion of coronary angiography without the need for access site crossover. The incidence of access site crossover was evaluated. A total of 2,389 patients underwent coronary angiography at our center during the study period, and 130 patients (5.44%) were found to have radial artery extreme tortuosity/loop, with a mean age of 74 years. Of these, 75 patients (58%) were men. Using our protocol, radial artery access was successfully achieved in 124 patients (95.4%) with a median total procedure time to successful initiation of coronary angiography of 60 s (IQR 30–120). Only 6 patients (4.6%) required crossover to an alternative access site, and no severe anatomical complications were observed. Success by protocol step was as follows: Step 1 in 48 (37%), Step 2 in 61 (47%), Step 3 in 10 (7.7%), and Step 4 in 5 cases (3.8%). The proposed four-step strategy represents a promising, safe, and effective algorithm for overcoming loops during transradial coronary angiography. Created in BioRender. Graidis, S. (2025) https://BioRender.com/z57kwul .