New advances offer hope to patients with CLI
LAS VEGAS — While critical limb ischemia presents many challenges, numerous new technologies and techniques are being developed to help this population, Peter Schneider, MD, said at VIVA 19.
“It’s not just that we have a critical mass of people coming together to solve the problem of CLI, but we’re also getting to the point where the field is maturing and the recognition is getting clearer that we need more tools and new tools to solve some of these problems. Not all of it is fancy new stuff,” Schneider, professor of surgery at the University of California, San Francisco, said during a presentation.
Schneider highlighted several innovations that could improve interventions for CLI, including:
- Assessment of tissue oxygen using an injectable microsensor (Lumee, Profusa). “Injecting the microsensor means the patient could be followed during a procedure to prompt questions about whether enough has been done,” Schneider said.
- Remote monitoring technologies, including a stent that can be remotely monitored (LivMor) and a digitized wound evaluation system (eKare), which could help solve “the discordance of all the different kinds of specialists involved with the patient’s care,” he said.
- Pedal access for crossing difficult lesions. “It gives us an ability where, if we can’t get through from above, we can get through from below, which cuts the rate of inability to cross,” Schneider said. “At multiple institutions around the world, this is being looked at and developed.”
- Serratoplasty (Cagent Vascular), which Schneider said is “a modification of the concept of scoring” and treats heavily calcified arteries.
- Lithoplasty (Lithotripsy System, Shockwave Medical), “which is intended to help you with those difficult lesions,” Schneider said. “We know that balloons alone [are] probably not the answer for patients with heavily calcified lesions.”
- Post-angioplasty dissection repair (Tack Endovascular System, Intact Vascular).
- Drug-coated balloons for treatment of below-the-knee lesions. The Lutonix system (BD) was shown to be effective for that indication, although FDA approval has not yet been granted, and other companies are developing similar products, Schneider said.
- A DCB designed to prevent arterial trauma (Chocolate Touch, QT Vascular/Trireme Medical).
- Sirolimus-eluting balloons, which have generated interest following concerns about a long-term mortality signal associated with paclitaxel-coated devices. “The key thing about sirolimus is that it absorbs very slowly,” Schneider said. “Delivering it by balloon in the peripheral arteries is a big challenge. We are a few years away from having these in our practice, but I think there will be a role for some of them.”
- Delivery of dexamethasone into adventitial tissue (Bullfrog, Mercator Medsystems).
- Below-the-ankle angioplasty. “Around 10% of patients in my practice need this,” Schneider said. “Now there are some data around it, especially from Japan. It has not shown improved limb salvage, but it did show faster wound healing.”
- Deep venous arterialization (LimFlow) in patients with so-called desert foot who are otherwise considered to have no options. “In these patients, there is essentially nothing going on in the foot,” he said. “The idea is that you puncture a vein, go into an artery, and cross into another vein. Then you have to lyse the valves to get blood flow and cover everything with an endovascular stent graft. There was a 75% limb salvage rate in patients who would otherwise have undergone amputation.”
“There is a dire sense of a pressing need [for patients with CLI], but at the same time there is a lot to look forward to,” Schneider said. “We’re going to have new options for these patients.” – by Erik Swain
Schneider P. Defining the CLI epidemic. Presented at: VIVA 19; Nov. 4-7, 2019; Las Vegas.
Disclosure: Schneider reports he received honoraria from Cardiovascular Systems Inc., Medtronic and Silk Road Medical and consulted for Boston Scientific, Cagent Vascular, Cardiovascular Systems Inc., LimFlow, Intact Vascular, Medtronic, Philips, Profusa, Silk Road Medical and Surmodics.