Developments in Coronary Chronic Total Occlusion PCIs
Balloon uncrossable CTOs are lesions that cannot be crossed with a balloon after successful guidewire crossing. These lesions are usually approached with a combination of lesion modification techniques (such as use of microcatheters and multiple balloons) and increased guide support (such as use of anchoring techniques and use of guide catheter extensions). Four 2013 publications provided novel insights in this area. Hu et al described the "wire-cutting" technique, in which 2 guidewires (A and B) are inserted into the distal true lumen, followed by advancing a balloon over guidewire A to the site of the occlusion abutting the proximal cap. The balloon is then inflated, pressing guidewire B between the balloon and the proximal cap, followed by rapid withdrawal of guidewire B, which "cuts" the proximal cap, facilitating balloon crossing. The weakness of this technique is the need to pass 2 wires into the distal true lumen. Michael et al described the "subintimal distal anchor" technique, in which a second coronary guidewire is advanced through the subintimal space distal to the occlusion site with a balloon subsequently inflated to "anchor" the guidewire that has crossed into the distal true lumen, thus facilitating balloon crossing on the initial wire. Kovacic et al reported that use of the Guideliner guide catheter extension (Vascular Solutions) was successful in 24 of 28 (85.7%) balloon uncrossable CTO cases. Finally, Fernandez et al reported successful crossing in 13 of 16 (81%) balloon uncrossable CTOs using excimer laser, without any significant complications; in some cases, procedural success was achieved with rotational atherectomy following laser application.
"Balloon Uncrossable" CTOs
Balloon uncrossable CTOs are lesions that cannot be crossed with a balloon after successful guidewire crossing. These lesions are usually approached with a combination of lesion modification techniques (such as use of microcatheters and multiple balloons) and increased guide support (such as use of anchoring techniques and use of guide catheter extensions). Four 2013 publications provided novel insights in this area. Hu et al described the "wire-cutting" technique, in which 2 guidewires (A and B) are inserted into the distal true lumen, followed by advancing a balloon over guidewire A to the site of the occlusion abutting the proximal cap. The balloon is then inflated, pressing guidewire B between the balloon and the proximal cap, followed by rapid withdrawal of guidewire B, which "cuts" the proximal cap, facilitating balloon crossing. The weakness of this technique is the need to pass 2 wires into the distal true lumen. Michael et al described the "subintimal distal anchor" technique, in which a second coronary guidewire is advanced through the subintimal space distal to the occlusion site with a balloon subsequently inflated to "anchor" the guidewire that has crossed into the distal true lumen, thus facilitating balloon crossing on the initial wire. Kovacic et al reported that use of the Guideliner guide catheter extension (Vascular Solutions) was successful in 24 of 28 (85.7%) balloon uncrossable CTO cases. Finally, Fernandez et al reported successful crossing in 13 of 16 (81%) balloon uncrossable CTOs using excimer laser, without any significant complications; in some cases, procedural success was achieved with rotational atherectomy following laser application.