MedTech Strategist | Mary Stuart

Intravascular ultrasound has been proven to make endovascular interventions safer, and good outcomes more durable, but only a minority of clinicians use it.

Two device imaging start-ups—Provisio Medical and Evident Vascular—are innovating to address barriers to the use of IVUS, with an initial focus on peripheral vascular disease, the largest potential endovascular market, and the one most in need because of the complexity of the anatomy and disease.

In early January 2024, the Journal of the Society for Cardiovascular Angiography & Interventions (JSCAI) published a report advocating for the use of intravascular ultrasound (IVUS) in peripheral arterial and deep venous interventions, the work of a multidisciplinary expert round table. Across interventional cardiology, interventional radiology, and vascular surgery, 15 physicians representing six professional societies weighed in on the value of IVUS. This was in recognition of both two decades of evidence that IVUS helps reduce adverse events during percutaneous coronary interventions (PCIs) and contributes to better outcomes, and the significant underutilization of this valuable tool in coronary and peripheral endovascular procedures.

IVUS yields far more information about vessels than conventional angiography, and two-dimensional C-arm fluoroscopy. With a cross-sectional view of the vessel, IVUS is excellent at showing stenosis, plaque burden, plaque morphology, reference vessel diameter, lesion length and eccentricity, dissections, and extrinsic and dynamic compression. It helps clinicians properly size vessels for the correct choice of pre-therapy vessel dilation strategies, stents and angioplasty balloons, to identify suitable landing zones and the presence of calcium that might need removal before stenting, to confirm the apposition of those devices to the vessel walls, and to reveal the not uncommon dissections that encourage restenosis and doom interventions to failure.

In addition, because the use of IVUS cuts down on the need to use angiography and fluoroscopy for vessel sizing, it reduces radiation exposure and minimizes iodinated contrast media, the latter an important benefit for patients with renal impairment.

Speaking with MedTech Strategist, the study’s lead author, interventional cardiologist Eric A. Secemsky, MD (Beth Israel Deaconess Medical Center and Harvard Medical School) noted, “In the coronary space, with the advent of drug-eluting stents, we see good outcomes for years after our procedures. But we haven’t gotten there yet in the peripheral space.” Indeed, peripheral vascular disease is a challenging space where vessels vary in diameter and mechanical stresses, and diseased segments are prone to be longer and more calcified. “We have gotten much better at acute technical success, but even with all the amazing technology that has come out, we are still looking for answers to give patients durable outcomes.” That’s why Secemsky believes IVUS is so important. “We are looking for more tools to augment what we can do for the patient, because we haven’t seen the same evolution here as in the coronary space.”

In deep venous disease, particularly in the iliofemoral region, where stents are placed to relieve extrinsic compression, IVUS also plays a valuable role in increasing the safety of procedures. “The risks of poor stent placement are much higher in the venous system,” says Secemsky, noting that the potential consequences of stent misplacement—embolization to the heart and lungs, and open surgery to address that event—are even less tolerable in younger, otherwise healthy patients with venous disease.

Vascular surgeon Paul Gagne, MD (Vascular Care Connecticut) was among the first investigators to validate the role of IVUS in improving the outcomes of endovascular venous interventions, as lead author on the VIDIO trial published in 2017. The study demonstrated that venous stenting was more successful when IVUS was used to evaluate patients and guide the procedure as compared to venography. Yet, Gagne says, “We still see stents embolizing to the heart and lungs, which means interventionalists aren’t getting the information they need from IVUS, because stents are undersized.”

According to Gagne, he has often said from the podium, “You can’t fix what you can’t see.” IVUS, he adds, gives clinicians vision that they don’t get with angiography.

A preponderance of data, largely on the coronary side, suggests that the advantages associated with using IVUS to guide interventional therapies result in lower rates of periprocedural adverse events and superior long-term clinical outcomes, in part because clinicians have enough information to choose the right treatment for the patient. At the ESC Congress in August 2023, interventional cardiologist Gregg Stone, MD (Icahn School of Medicine at Mount Sinai, New York) presented a meta-analysis of 20 randomized clinical trials to compare results of percutaneous coronary interventions guided by angiography to those guided by intravascular imaging. The study arms were randomized across angiography (5,390 patients), IVUS (3,120 patients), optical coherence tomography (OCT; 2,826 patients), and either IVUS or OCT (1,092 patients). The procedures guided by intravascular imaging benefitted from significant reductions in all the following negative outcomes: target lesion failure (31% reduction), cardiac death (cut by 46%), target lesion revascularization (down by 29%), and stent thrombosis (down by 52%).