Conquering CTOs

I have no doubt the vast majority of the Journal’s readers would find CTO recanalization to be quite a familiar term. However, one would not need to go back that many years to be reminded that endovascular treatment of CTOs (chronic total occlusions) was one of the “holy grails” of endovascular therapy since its inception. CTO-related challenges abound: the tough fibrous cap (both at the entry and even the exit point) that can be quite difficult to penetrate and cross before recanalization is even possible; the ability to stay within the true vessel lumen as the lesion is crossed; and re-entering the true lumen beyond. Calcification and (on occasion) tortuosity can of course further expand on such challenges. Success rates have been less than optimal, and complications relatively frequent.

Now, let’s shift forward all the way to 2011: CTOs occupy center-stage, and the newly acquired capability to treat many such lesions successfully has added a whole new dimension to the power and reach of endovascular therapy. CTO-inspired technologies have proliferated in recent years, both to aid in traversing the totally occlusive lesion and to facilitate re-entry past the occlusion. Many older interventional specialists (such as yours truly) continue to rely on the time-tested simple approach based on the use of a Glidewire and support catheter for both crossing and re-entry. But this may not last much longer as newer technologies continue to prove their superiority.

This article by Staniloae et al¹ is quite interesting and of considerable practical value. The authors describe their experience using a relatively novel CTO-crossing device for endovascular recanalization of totally occlusive arterial lesions in the lower extremities. Bard’s Crosser catheter was designed specifically for rapid and safe penetration of CTOs, and to follow an intraluminal pathway to effect successful recanalization. It relies on the mechanical creation of a 0.014-inch guidewire-compatible channel across the total occlusion into the distal vessel lumen using ultrahigh-frequency vibrations. A re-entry device can be used adjunctively if the Crosser catheter fails to maintain intraluminal position past the lesion. Once guidewire crossing has been achieved, definitive endovascular treatment can be completed using standard interventional techniques (angioplasty, stenting, and the like). While the study was relatively small as only 56 patients were enrolled, the overall results were quite impressive. The majority of failures (n=17) related to re-entry issues — not unexpectedly. Predictably also, lesion length and calcification emerged as predictors of a higher failure rate. Most remarkably, the authors documented no perforations whatsoever. This represents an improvement over all other known methodologies and may well be related to this technology’s ability to differentiate between plaque and normal vessel wall according to their differing elastic properties. Such capabilities were particularly impressive in cases of tibial artery CTOs where the success rate was nothing short of phenomenal. Crosser outcomes for the SFA, on the other hand, were not spectacular attesting to the many acknowledged challenges facing devices and operators maneuvering within heavily diseased SFAs.

In the end, it would appear fair to predict that Bard’s Crosser CTO device is destined to occupy an important place in the armamentarium of those treating arterial CTOs, particularly in the tibial-artery territory where success rates have been phenomenal. The apparent excellent safety is another noteworthy feature of this device.

Reference

1. Staniloae CS, Mody KP, Yadav SS, Endoluminal treatment of peripheral chronic total occlusions using the Crosser^® Recanalization Catheter. J Invasive Cardiol 2011;23:359-362.   

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Dr. Frank J. Criado is a Board-Certified Vascular Surgeon and Endovascular Specialist
at the Union Memorial Hospital-MedStar Health in Baltimore, Maryland.
Disclosure: Dr. Criado has completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr. Criado is a member of the speaker’s bureau for Medtronic. He reports honoraria from and consultancy to Medtronic.
Address for correspondence: Frank J. Criado, MD, FACS, FSVM, Vascular Surgeon and Endovascular Specialist, Union Memorial Hospital-MedStar Health, 3333 N. Calvert St. Suite 570, Baltimore, Maryland 21218. Email: frank.criado@medstar.net