Complex CTOs

CTO REVASCULARIZATION Series: Part 2A

Before discussing how to cross a long or multilevel CTO, we need a more fundamental question: which vessel do we recanalize? The strategic framework of the 2019 Global Vascular Guidelines — Target Arterial Path, GLASS, and the role of the angiosome — defines everything that follows.

Long femoropopliteal CTOs (>15–20 cm) define a TASC II D / GLASS FP grade 4 lesion — the morphological hallmark of the second order of complexity in CLTI

Long Lesions and multilevel disease - The Strategic Question

💡

For a better reading experience — especially to view the figures and illustrations — click “View in browser” at the top of this email.

About Me | My Book | Previous posts | Manage Account

After our first article on severely calcified arteriopathy, we turn to the second order of complexity in CTO recanalization: long lesions and multilevel disease. This is, in my experience, the most frequent scenario in CLTI patients — and it is not uncommon for the two orders of complexity to overlap, with long, severely calcified CTOs representing some of the toughest cases we face at the angio-suite.

There is no universally accepted threshold for what makes a CTO long. TASC II and the GLASS classification proposed by the Global Vascular Guidelines (Conte et al., J Vasc Surg 2019) both consider a femoropopliteal occlusion exceeding 20 cm — or involving the distal popliteal artery — as the highest complexity grade (TASC II D, GLASS FP grade 4).

In practice, I tend to consider 15–20 cm the threshold beyond which the wire-handling complexity of the lesion changes qualitatively.

Multilevel disease, on the other hand, is the rule rather than the exception in CLTI: most patients present with multiple occlusions scattered along the infrainguinal tree, combining femoropopliteal and infrapopliteal segments in various permutations.

Which vessel to recanalize

Before discussing how to cross a long or multilevel CTO, we need to answer a more fundamental question: which vessel do we choose to recanalize? In multilevel CLTI, this decision is upstream of any technical consideration about wires, catheters or crossing techniques.

Side-by-side schematic of two crossing strategies for a long femoropopliteal CTO: subintimal (left), guidewire looping between plaque and wall; intraluminal (right), wire through the plaque.

CTO REVASCULARIZATION Series — Part 2B

Once the Target Arterial Path is chosen, the technical question becomes how to cross the CTO. In long femoropopliteal occlusions the relationship between intraluminal and subintimal recanalization is more nuanced than the textbook sequence suggests — three scenarios worth distinguishing.

CTO REVASCULARIZATION

Heavy calcification is not just a technical obstacle — it changes the rules of the game entirely. In this issue: why the subintimal approach often fails in the highly calcified pattern, and why staying endoluminal is both the harder and the smarter choice

What Does Infrainguinal “Complex Recanalization” Really Mean?

We use the term all the time. But complex recanalization is not an anatomical category — it’s a decision point. Here’s the operational definition that changes how you plan your next CTO case.

When to Use Antegrade Access in Infrainguinal Revascularization

Antegrade access is the default for infrainguinal revascularization — until proven otherwise. Two real exceptions, two false exceptions, and the one adjustment that changes everything.

Read more

CTO REVASCULARIZATION Series — Part 2B

CTO REVASCULARIZATION

What Does Infrainguinal “Complex Recanalization” Really Mean?

When to Use Antegrade Access in Infrainguinal Revascularization