Crossing a chronic total occlusion (CTO) can be tricky, but it’s an important skill set, said Fadi A. Saab, MD, from Advanced Cardiac & Vascular Centers for Amputation Prevention in Grand Rapids, MI, given that CTO rates range from 50% to 60%, with the rate of failure in crossing CTOs lying somewhere between 20% and 40%.
Saab told attendees of AMP 2020 Virtual that most operators will not attempt retrograde tibiopedal access unless a traditional attempt to cross the CTO in antegrade fashion has been attempted.
“This traditional approach provides a false sense of security and could arguably be harmful in some instances given that after a failed antegrade attempt most physicians tend to stop and reschedule the patient for another procedure,” he said. “This, in our opinion, predisposes patients to another hospitalization, higher rate of complication rates and so on.”
Saab and colleagues, including Jihad Mustapha, MD, the director of the AMP course, published a paper in 2018 describing their CTOP classification. The CTOP (Chronic Total Occlusion Crossing Approach based on the Plaque Cap Appearance) was a retrospective analysis evaluating CTO cap morphology. Based on cap morphology determined by angiography and duplex ultrasonography, the classified CTOs into 4 types (I, II, III, or IV) based on the concave or convex shape of the proximal and distal caps.
The group found that Type I CTOs were the easiest to cross in an antegrade fashion and had a lower incidence of severe calcification, whereas type IV lesions were more likely to be crossed retrograde from a tibiopedal approach.
Access conversion, or need for an alternate access, was commonly seen in types II, III, and IV lesions, with lesion length and severe calcification upping the chances of needing access conversion.
“We found that the physicians had to convert the access from antegrade to retrograde access in about 25% of the cases,” said Saab. “And they started with dual access in about 30% of the cases, so for almost 60% or 65% of the cases dual access was required.”
“CTOP remains one of the most important trials to categorize CTOs in a simple, easy to apply process. Lesion length, calcium content and CTO types II and III are the major players for access conversion, and correct planning…saves time and increases the success rate,” said Dr Saab.
“Starting with pedal access may be potentially the standard of care as experience is gained among operators,” he concluded, adding that it saves the patient from the risks of a second procedure, saves the operator time, and offers a greater chance of overall success.