Study Evaluates CTO Crossing Approach Based on Plaque Cap Morphology

February 28, 2018—Online in Journal of Endovascular Therapy (JEVT), Fadi Saab, MD, et al published findings on an approach to crossing chronic total occlusions (CTOs) based on a plaque cap morphology, the CTOP classification system. The investigators assessed this approach's ability to predict successful lesion crossing.

As summarized in JEVT, the investigators conducted a retrospective analysis of imaging and procedure data from 114 consecutive symptomatic patients (mean age, 69 ± 11 years; 84 men) with claudication (Rutherford category 3) or critical limb ischemia (Rutherford category 4–6) who underwent endovascular interventions for 142 CTOs. CTO cap morphology was determined from a review of angiography and duplex ultrasonography and were classified into four types (CTOP types I, II, III, or IV) based on the concave or convex shape of the proximal and distal caps.

The investigators reported that statistically significant differences among groups were found in patients with rest pain, lesion length, and severe calcification.

CTOP type II CTOs were most common and type III lesions the least common. Type I CTOs were most likely to be crossed antegrade and had a lower incidence of severe calcification. Type IV lesions were more likely to be crossed retrograde from a tibiopedal approach. CTOP type IV was least likely to be crossed in an antegrade fashion.

Access conversion, or need for an alternate access, was commonly seen in types II, III, and IV lesions. Distinctive predictors of access conversion were CTO types II and III, lesion length, and severe calcification.

CTOP type I lesions were easiest to cross in an antegrade fashion and type IV the most difficult. Lesion length > 10 cm, severe calcification, and CTO types II, III, and IV benefited from the addition of retrograde tibiopedal access, concluded the investigators in JEVT.

In a commentary provided to Endovascular Today, Dr. Saab and Lead Investigator Jihad A. Mustapha, MD, stated, "The CTOP trial is the first trial that categorizes peripheral CTOs into four distinct simple types. Furthermore, by following the direction of crossing the CTO (antegrade, retrograde, dual), we created a simple algorithm that can help guide the clinician's decision to choose any type of arterial access (femoral or tibial). All patients enrolled had complex CTOs, with the majority being critical limb ischemia patients. The implications for daily practice are significant and will help save patients' limbs and, in certain instances, lives."