RESUMO
Guiding catheter extensions (GCEs) have become indispensable tools in the modern approach to percutaneous coronary intervention (PCI). The support offered during complex PCI of uncrossable, or tortuous lesions is particularly valuable in the setting of chronic total occlusions (CTO), both for conventional anterograde wire escalation and for anterograde or retrograde dissection and re-entry techniques. This EuroCTO consensus document describes the use of GCE during CTO recanalization and provides a practical guide to anatomies and techniques in which these devices are applicable. We describe the peculiar features of the most-used device and the practical technique for GCE delivery in standard PCI; further specific indications for antegrade and retrograde CTO PCI are discussed in a specific section. In the antegrade approach, the GCEs may be useful to increase support or facilitate antegrade dissection and re-entry techniques, while in the retrograde approach for reverse controlled antegrade and retrograde tracking, to increase retrograde support for gear delivery, for treatment of CTO in bifurcation and ipsilateral externalization with a single guide catheter. The last section of the paper describes GCE-related complications, challenges, limitations, and future perspectives.