Interventional Rounds Radial Approach for Percutaneous Coronary Interventions on Chronic Total Occlusions: Technical Issues and Data Review Francesco Burzotta, 1 * MD, PHD, Maria De Vita, 2 MD, PHD, Thierry Lefevre, 3 MD, Antonella Tommasino, 1 MD, Yves Louvard, 3 MD, and Carlo Trani, 1 MD Objective: To overview the scientific data and the technical details regarding percutane- ous 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 stud- ies comparing the success rates between a first and a later period of practice, a signifi- cant 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 recana- lization 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. V C 2013 Wiley Periodicals, Inc. Key words: transradial approach; chronic total occlusion; percutaneous coronary inter- vention; vascular complications INTRODUCTION Chronic total occlusion (CTO) percutaneous coro- nary intervention (PCI) represents an evolving field of interventional cardiology [1–8]. According to the standard practice of the majority of CTO-dedicated centres and operators, PCI on CTO are attempted using large guiding catheters and trans-femoral approach (TFA). Yet, transradial approach (TRA) is a valuable 1 Institute of Cardiology, , Catholic University of Sacred Heart, Rome, Italy 2 Interventional Cardiology, Morgagni-Pierantoni Hospital, Forl  ı, Italy 3 Interventional Cardiology, Istitut Cardiovasculaire Paris Sud, Massy, France Conflict of interest: Nothing to report. *Correspondence to: Francesco Burzotta, MD, PhD; Institute of Car- diology, Catholic University of Sacred Heart, L.go Gemelli 1, 00168 Rome, Italy. E-mail: f.burzotta@rm.unicatt.it Revised 23 June 2013; Revision accepted 27 June 2013 DOI: 10.1002/ccd.25118 Published online 5 July 2013 in Wiley Online Library (wileyonlinelibrary.com). V C 2013 Wiley Periodicals, Inc. Catheterization and Cardiovascular Interventions 83:47–57 (2014)