Radial approach for percutaneous coronary interventions on chronic total occlusions: technical issues and data review

Objective: To overview the scientific data and the technical details regarding percutaneous coronary interventions (PCI) on chronic total occlusions (CTO) by radial approach.

Background: Trans-femoral approach is commonly regarded as the standard for PCI on CTO.

Methods: A systematic search in Medline and in the main international websites was realized. Key data were extracted and analyzed using standard meta-analytic techniques. Bench test assessment of compatibility between different combinations of interventional devices (required for CTO recanalization techniques) and the following guiding catheters was performed: 5 Fr, Sheathless 6.5 Fr, 6 Fr, Sheathless 7.5 Fr and 8 Fr.

Results: No prospective randomized study was found, whereas 13 observational studies on 3,501 CTOs treated by radial approach were identified. Overall, the crossover to femoral access rate ranged between 0 and 5.8%. Access site complications were noted in <1% of cases and in-hospital major adverse events were reported in 0-3.8% of patients. PCI success was significantly influenced by the learning curve: In the five studies comparing the success rates between a first and a later period of practice, a significant improvement was observed (OR, 95% CI: 0.30, 0.39-0.51; P < 0.001). The technical details relevant to approach a CTO by transradial access are discussed, and the original results of bench tests provide details regarding the compatibility of various CTO recanalization techniques with specific guiding catheter sizes.

Conclusions: The transradial access represents a promising alternative to trans-femoral access to treat patients undergoing CTO PCI in high-volume transradial centres. The presented data may be useful to plan transradial PCI attempts on CTO lesions.