Further advancement in the percutaneous revascularization of coronary chronic total occlusions: the redefined "Minimalistic Hybrid Approach" algorithm.

A careful angiographic assessment of a chronic total occlusion (CTO) is essential for optimal procedural planning. In the classic Hybrid Approach, the insertion of two guiding catheters at the beginning of the intervention is recommended. This is fundamental to perform simultaneous double injection, to achieve complete visualization of the coronary circulation and to choose the best starting strategy between antegrade wire escalation (AWE), antegrade dissection and re-entry (ADR) and the retrograde techniques (retrograde wire escalation [RWE] and retrograde dissection and re-entry [RDR]). In the Hybrid Algorithm the set-up is the same, regardless of the chosen first strategy, and therefore routinely uses double access. Because revascularizations of CTOs commonly require large bore catheters (7-8 French) to ensure high back up support, the femoral arterial access is preferred by most of the operators. However, the use of a double access, large introducer sheaths and femoral approach are associated with a greater risk of access-related complications and even the occurrence of major adverse cardiovascular events. We have previously proposed an algorithm, called "Minimalistic Hybrid Approach", which aims to limit the routine use of dual injection, and to favour the use of trans-radial access and smaller (6-7 French) guiding catheters. In this algorithm the chosen starting strategy depends on the complexity of the lesion assessed by J-CTO score and on the presence of favourable contralateral interventional collateral circulation. However, this novel algorithm proved to have some limitations, such as the non-specific evaluation of CTOs with ipsilateral collateral circulation and the too arbitrary choice of the starting strategy based on a J-CTO score cut-off. These considerations led to the development of an "updated" Minimalistic Hybrid Approach algorithm that takes into account the type of collaterals (ipsilateral or contralateral) and the "a priori" choice of the hybrid technique, with the highest chance of success in that specific CTO lesion (independently from the J-CTO score). One important aspect that makes this algorithm unique is its "dynamicity": not only for the technique to be used, as in the classic hybrid algorithm (shifting between AWE, ADR, RWE and RDR), but also for the set-up, with access site and French size to be adapted during the PCI to the technique adopted. We believe that this novel approach could further improve the safety of CTO-PCI without losing its current efficacy.