Recent Progress of the Use of Interventional Therapy for Chronic Total Occlusion

Abstract

Chronic total occlusion (CTO) remains one of the most challenging lesion subsets for interventional cardiologists due to a low success rate and higher incidence of restenosis, especially with current use of bare metal stents (BMSs). However, successful CTO revascularization has a beneficial effect on long-term survival and relief of angina. With recent advances in technology (with the use of special techniques and devices), the initial success rate of recanalization of occlusions is quite high (approximately 90%). However, the long-term clinical outcome of the use of bare metal stents is not satisfactory due to a high restenosis rate. Recently, the introduction of the sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) has shown favorable clinical outcomes, such as a reduction in the restenosis rate in patients with CTOs. Consequently, the use of the new types of stents can reduce the incidence of major adverse cardiac events detected at follow-up. (Korean Circ J 2008;38:295-300)

Current status of percutaneous coronary intervention of chronic total occlusion

“…In a report of 31 CTO cases, most of which had had a previous failed attempt, re-canalization with this technique was successful in 21 patients. However, it carries a higher potential for perforation than most other techniques (Nakamura and Bae, 2008).…”

“…(3) The second wire can find the true lumen easier than the first wire, using the first wire as a landmark. In this situation, the tapered-tip wires are considered more adequately for the second wire than conventional wires as they can create a channel different from that created by the first wire, owing to their stiff and tapered tips (Nakamura and Bae, 2008).…”

“…After selection of the first guidewire, the wire has to penetrate the CTO lesion and advance to its core, while avoiding progress in a subintimal pathway, and then to cross to the distal edge of the lesion. If there are difficulties during this procedure, it may be necessary to change the guidewires and to use several special techniques to resolve the situation (Nakamura and Bae, 2008).…”

“…The guidewire should have "stiffness, steerability and slipperiness" inside the CTO lesion. However, as there is no perfect CTO guidewire, it is most important to select an appropriate wire for each CTO condition (Nakamura and Bae, 2008).…”

“…A non-lubricated wire is important, especially when attempting to penetrate the distal fibrous cap of a CTO. Thus, lower-force wires are generally used initially and if highly calcified lesions are encountered, they should be substituted with more powerful, stiffer guidewires that are suitable for each situation of a CTO lesion (Nakamura and Bae, 2008).…”