Crossing Algorithm for Infrainguinal Chronic Total Occlusions: An Interdisciplinary Expert Opinion Statement.

A crossing algorithm was developed for the endovascular treatment of peripheral chronic total occlusive lesions (CTOs) to educate, guide, and appropriately influence clinical practice aiming at harmonization and standardization of endovascular procedures. The following steps are proposed: One, duplex sonography and if required computed tomography or magnetic resonance angiography for the selection of the optimal access site. Two, angiographic evaluation of the proximal/distal cap morphology, presence of collaterals at the origin of the proximal cap and at the distal vessel refilling site. In addition, evaluation of distal vessels, including their diameters and quality, and the presence of calcification or stents within the occlusion zone. Three, antegrade wiring strategies, guidewire (GW) and support catheter technology, as well as GW escalation strategies. Stop the antegrade attempt depending on clinical indication for peripheral artery disease treatment and the presence of retrograde options. Four, retrograde access site, support catheter, or sheath insertion and wiring technology from distally. Five, considering strategy change when progress cannot by achieved, using advanced bidirectional techniques and re-entry devices. Six, in case of successful GW passage from retrograde, GW externalization and treatment from antegrade. Management of the retrograde access by internal or external hemostasis at the end of the procedure. Alternatively, stop the procedure if no progress can be obtained within 3 hours or in case of specific complications. By establishing the algorithm in the daily routine of endovascular specialists, improvements in vessel- and patient-specific outcomes are anticipated. In addition, future research, and continuous collaboration between experts is warranted.