CTO PCI has a technology problem, not an evidence problem.

The data supporting revascularization of chronic total occlusions is substantial and growing. Success rates at expert centers exceed 90%. Symptomatic improvement is documented across multiple registries and trials. The clinical case is strong.

Yet CTO PCI remains underutilized. Patients are referred to surgery that a third of them will never receive. Also, data from the old SYNTAX trial indicate that CTO is the strongest predictor of not receiving complete revascularization even in the CABG arm. They are left on medical therapy in territories with documented ischemia. The myths that justify inaction have been thoroughly debunked. Dr. Gregor Leibundgut, Head of Interventional Cardiology, recently assembled those counterarguments in a single LinkedIn graphic that earned nearly 500 reactions. He called the collection of anti-CTO arguments what they are: the Cherry-Picker Manifesto.

So if the evidence is there, why does the manifesto persist? Because the tools have not caught up to clinical logic. CTO crossing remains mainly a blind procedure. Operators advance wires through 100% occluded vessels guided by fluoroscopy and tactile feedback, unable to see where they are in the occlusion, if there are in front of unrecognized side branches, if they are within the plaque or the vessel wall. Success depends overwhelmingly on operator volume and experience. The gap between elite CTO programs and community practice is enormous. And the procedural burden of contrast and radiation excludes the patients who may need revascularization most.

At VerAvanti we are developing the Scanning Fiber Endoscope platform to change that equation. SFE provides forward optical visualization at a sub-millimeter profile using piezo-actuated resonant fiber scanning with RGB laser illumination. No distal chip. No semiconductor at the tip. A categorically different architecture from any chip-on-tip camera catheter on the market or in development. The platform is investigational. The IIR at UW Medicine under Dr. Lorenzo Azzalini is underway. But the clinical logic that connects each myth on Leibundgut’s list to a visualization solution is worth examining in detail.

Here is what the data says, myth by myth, and where technology fits.

Myth 1: “Good Collaterals Protect the Myocardium”

The core point: Collaterals create a false sense of security that delays revascularization. When the decision is finally made to intervene, the operator crosses blind. Forward visualization could change both sides of that equation.

Good collaterals are equivalent to roughly 90% stenosis. They do not provide normal perfusion. Multiple studies using invasive pressure measurements have confirmed that even Rentrop grade 3 collaterals deliver fractional flow reserve values that would qualify as physiologically significant. The territory looks fed on angiography. The physiology says otherwise. This gap between appearance and reality is what sustains the myth. And the myth sustains inaction.

When intervention proceeds, the operator must cross a lesion that is by definition 100% occluded. Today that crossing relies on fluoroscopy and tactile feedback. That is what the SFE platform is designed to do.

A skeptical interventionalist will immediately ask: we already have IVUS and OCT. The answer is that SFE is not another cross-sectional modality. IVUS and OCT look at the vessel wall in a radial plane after the wire has crossed. They are indispensable for stent sizing and optimization. SFE provides forward visualization. It looks ahead of the wire tip, before crossing has occurred. IVUS and OCT are the rearview mirror and side mirrors. SFE is the windshield. They are complementary, not competitive.

Myth 2: “The Vessel Is Already Totally Occluded. It Can’t Get Worse”

The core point: Untreated CTOs are not benign. They are on observational studies independently associated with worse outcomes, but there is a lack of RCT evidence that opening them improves hard clinical outcomes. If we accept the clinical imperative to treat, then the barrier is technical. Any technology that increases crossing probability on first attempt changes the risk-benefit calculus.

The PROGRESS-CTO registry has tracked more than 21,000 CTO PCI procedures across 60 centers globally. Patients with untreated CTOs are far worse than matched patients without them. The occluded vessel is a source of ongoing ischemic burden, electrical instability, and reduced ventricular function

The immediate objection to introducing a new visualization device here is procedure time and cost. That assumes visualization adds a step. In practice, it is designed to replace multiple steps. Consider a failed antegrade wire escalation: the operator switches wires repeatedly, contrast injections increase, and if antegrade fails, retrograde access is attempted. Each escalation adds time, contrast, radiation, and complication risk. If forward visualization enables first-pass crossing through identified microchannels, the net procedure time could decrease. We have built a hospital economics model for this scenario. Math works at current pricing assumptions when you account for avoided escalation, reduced contrast-associated AKI, and shortened lab time. But the model needs clinical validation.

Myth 3: “Treat Other Vessels and Reduce Overall Ischemic Burden”

The core point: Incomplete revascularization produces worse outcomes. The SFE’s sub-millimeter profile is designed to access vessels that no chip-on-tip camera catheter can reach. That is not an incremental size advantage. It is a categorical one that could make complete revascularization possible in cases that are currently abandoned.

The logic of treating other vessels while leaving a CTO untouched sounds pragmatic. In practice it creates a revascularization gap. Patients with incomplete revascularization have higher rates of repeat intervention, more angina, and worse long-term prognosis. The EuroCTO trial found significant improvements in symptoms including dyspnea, angina, and quality of life when CTOs were treated. These are not soft endpoints. They are the outcomes that matter to patients.

A fair challenge: what about heavily calcified caps where optical imaging adds limited value? This is a legitimate concern. SFE uses reflected light optics. It is not designed to image through calcium the way IVUS penetrates tissue ultrasonically. However, pathological studies of CTO morphology have consistently identified heterogeneous composition within the same lesion: dense fibrous tissue, microchannels, foam cells, and calcium deposits. The clinical utility of SFE does not require imaging through the entire cap. It requires identifying and navigating the softest path through heterogeneous tissue.

That is a surface visualization task, not a penetration imaging task. Will there be cases so densely calcified that SFE adds limited value? Almost certainly. Those cases may still require atherectomy or advanced plaque modification. SFE is not positioned as a universal solution for every CTO morphology. It is designed to expand the toolbox for the substantial majority of cases where microchannel architecture exists.

Myth 4: “Send the Patient for CABG Instead”

The core point: CABG is not the reliable fallback it is assumed to be. One-third of referred CTO patients never receive a graft on the CTO vessel. SVG patency data is sobering 50% open at 10 years. If surgery is not the safety net, then improving the percutaneous pathway is not optional. It is essential.

A Circulation review of SVG failure rates reported that 3% to 12% of grafts occlude before hospital discharge, 8% to 25% fail within the first year, and long-term patency at a decade sits at 50–60%. The VA Cooperative Studies Trial found 10-year SVG patency of 61% compared to 85% for internal mammary artery grafts. For vessels 2.0 mm or smaller, SVG patency dropped to 55%. A significant proportion of CTO patients referred for CABG are turned down by cardiothoracic surgery due to anatomy, comorbidities, or perceived risk.

These patients return to the cath lab or receive no revascularization at all. And post-CABG CTO PCI success rates are notably lower: RECHARGE registry data showed 71.9% success in post-CABG patients versus 88.7% without prior CABG.

I can already hear the response: every pre-commercial device company claims they will change everything, and most fail. True. I have been in medical devices long enough to have seen it firsthand. The graveyard of promising technology is large. So here is what I would ask a skeptic to evaluate. Is the unmet need real? The data in this blog post comes from PROGRESS-CTO, the VA Cooperative Study, Circulation, and the Journal of Invasive Cardiology. We did not manufacture the need. Is the engineering differentiated? SFE uses piezo-actuated resonant fiber scanning with RGB laser illumination. No distal chip. No semiconductor at the tip. No chip-on-tip catheter can match a sub-millimeter form factor.

The physics do not allow it. Skepticism is warranted. Dismissal without evaluating the specifics is not skepticism. It is reflex.

Myth 5: “No Hard Evidence Supports CTO PCI”

The core point: The absence of a definitive RCT does not mean the absence of evidence. The data is substantial. And new visualization technology creates a unique opportunity to generate the controlled data this field has been missing.

The lack of a landmark randomized trial has been the single most effective weapon in the cherry-picker’s arsenal. It is also a red herring. CTO PCI makes blind randomization extraordinarily difficult. You cannot sham a coronary intervention. The ORBITA-CTO pilot trial is attempting a placebo-controlled design, but enrollment remains challenging.

Meanwhile, the PROGRESS-CTO registry has generated a decade of prospective data from 40 centers. The EuroCTO trial demonstrated symptomatic benefit. 2026 literature review confirmed success rates above 90% at expert centers with declining radiation exposure.

The evidence is not perfect. It is substantial.

The SFE platform has not been tested in a randomized trial. It has not been cleared by the FDA. Making claims about clinical outcomes at this stage would be irresponsible and we will not do it. The SFE technology was originally developed at the University of Washington and has been demonstrated in preclinical settings. VerAvanti holds the exclusive commercial license. Every device that is now standard of care was once pre-clinical. The question is not whether data exists today. It is whether the clinical hypothesis is sound and whether the evidence plan is credible. We believe both are true. We intend to prove it.

Myth 6: “CTO PCI Is Risky with Low Success Rates”

The core point: Success rates at expert centers are excellent. The problem is that “expert centers” describes a ballpark of 20-30 in the US, and probably less than 10 per country in the EUof programs. The gap between elite operators and the broader interventional community is the single largest barrier to CTO PCI adoption. Visualization technology could narrow that gap and expand the treatable population dramatically.

The PROGRESS-CTO registry documented a climb from 81.6% technical success in 2016 to 88.1% in 2021. High-volume centers routinely exceed 90%. A 2026 literature review confirmed these numbers with concurrent reductions in radiation exposure. But those figures come with a critical qualifier: at experienced centers. A UK non-surgical center reported 50% success among general interventional cardiologists versus 90.1% among dedicated CTO operators in the same institution. An Indian tertiary center reported 75% overall success with dramatically higher complication rates in failed cases: 34% coronary dissection, 17% perforation, and 9.4% cardiac tamponade in unsuccessful procedures versus 5%, 2.5%, and 2.5% in successful ones. The gap between elite programs and community practice determines who gets treated.

An experienced CTO operator will rightly point out that success is about operator skill, not technology. Absolutely true. Wire handling, collateral anatomy, decision-making under pressure, and the judgment to know when to stop are irreplaceable. But consider the parallel. Laparoscopic surgery did not replace surgical skill. It gave skilled surgeons better visual access. Robotic surgery did not eliminate experienced operators. It extended their precision. In both cases, technology amplified existing expertise and made complex procedures accessible to a broader base of qualified practitioners. Those general interventionalists reporting 50% success are not unskilled. They are experienced cardiologists who perform complex PCI every day. What they lack is the volume-driven pattern recognition that comes from doing 100+ CTO cases per year. Visualization could partially compensate for that experience gap. Not eliminate it. Narrow it.

There is another limitation to address honestly. The current SFE PRIME IV configuration is designed for antegrade use. It does not address retrograde crossing via collateral channels, which accounts for a meaningful percentage of contemporary CTO PCI. Two responses.

First, antegrade wire escalation remains the initial strategy in most cases. PROGRESS-CTO data shows 55% of successful crossings were achieved with antegrade wire escalation. If SFE improves antegrade success, fewer cases require retrograde escalation. The best retrograde case is the one you never need.

Second, the SFE platform architecture is inherently flexible. Future iterations could potentially address retrograde navigation, but that is beyond our current scope. We are focused on proving the antegrade application first. One indication. One evidence base. One clearance at a time.

The Dimension Nobody Is Discussing: Contrast and Radiation

The core point: Every myth on the list focuses on whether to treat. None addresses the procedural burden of how we treat. Patients with advanced CKD are excluded from CTO PCI because the contrast risk exceeds the perceived benefit. Direct visualization is designed to reduce that burden and reopen the door for the patients who need it most.

Complex CTO cases involve prolonged fluoroscopy and heavy contrast loads. Truong et al. published a landmark 2025 study in Circulation: Cardiovascular Interventions examining ultra-low contrast PCI in severe renal failure. The observed rate of contrast-induced AKI was 1.2% versus a Mehran-predicted rate of 21.2%. That gap represents a population who could benefit from CTO revascularization if the contrast burden could be managed.

Direct forward visualization is designed to reduce reliance on fluoroscopy and contrast injection. If an operator can see the vessel lumen optically, each contrast injection provides confirmation rather than primary navigation. Fluoroscopy time drops because the guidewire is not being advanced blindly. For the interventional community, this is not a peripheral benefit. It may be the most practical argument for optical visualization in the cath lab.

The Manifesto Deserves a Technology Response

I have tried to lead each section of this piece with the point before the proof. Where technology has limitations, I have named them. Where the data does not yet exist, I have acknowledged it. The interventional community does not need another sales pitch. It needs a credible plan to close the gaps that keep patients from being treated.

The Cherry-Picker Manifesto persists because the tools make it convenient. Change the tools and you change the math. That is what we are building at VerAvanti. Not a better version of what exists. A fundamentally different approach to seeing inside the coronary artery.

The Cherry-Picker Manifesto is wrong. Dr. Leibundgut is right to say so. And the SFE platform is designed to make it irrelevant.

Disclosure: The VerAvanti SFE platform is investigational and has not been cleared or approved by the FDA. Forward-looking statements regarding clinical capabilities reflect the intended design of the technology and are not claims of current performance. All clinical data cited in this post are from published, peer-reviewed sources and publicly available registries.