Aspectos clínicos e técnicos atuais das abordagens anterógrada e retrógrada da interven？？o coronária percutanea para a oclus？o cr？nica

percutaneous coronary intervention for the treatment of chronic total occlusions (cto) has made remarkable progress in recent years. first of all, appropriate angiographic evaluation is essential to provide clear imaging of the coronary arteries and their branches. observe in detail the pattern, the length and the direction of the cto, the condition of the side branches, the pattern of vessels distal to the occluded segment, and the extent of calcification. evaluate each of the collateral pathways very carefully, and identify the course from the origin to the termination in the distal part of the occluded vessel. secondly, selecting adequate devices for treatment is very important. the antegrade approach, using conventional guidewire and microcatheters is always the first choice. progressively more rigid guidewires may be required, as well as special devices and techniques. the retrograde approach is indicated when the antegrade approach fails, in cases where the entry point of the occlusion is not identified or in patients with extremely calcified lesions. the optimal collateral access for this technique is a wide and straight septal branch, but such ideal vessel is rarely found. the retrograde approach is explained in details, as well as suggestions to overcome eventual obstacles during the procedure. the experience accumulated at our service, along with the different strategies and the use of adequate devices has led to a current procedure success rate in over 90% of the cases of cto.