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Role of atherectomy in endovascular interventions up for debate
NEW ORLEANS — Atherectomy appears to have its place in practice, but experts remain somewhat divided over how judiciously the procedure should be used in endovascular interventions.
At the American College of Cardiology Scientific Session, Sanjum S. Sethi, MD, FACC, assistant professor of medicine at the Center for Interventional Vascular Therapy, Columbia University Irving Medical Center and NewYork-Presbyterian Hospital, argued that atherectomy is needed for vessel preparation and is appropriate in most femoropopliteal interventions.
In contrast, Mark C. Wyers, MD, FACS, program director of vascular fellowship and vascular residency in the division of vascular and endovascular surgery at Beth Israel Deaconess Medical Center, contended that atherectomy should be used sparingly and only in select patients, especially in an era of better stent performance.
Both speakers, though, noted that they are not completely on opposites of the fence. Rather, Sethi and Wyers harbor different viewpoints about when atherectomy is appropriate.
Use in calcified lesions
Heavily calcified lesions present operators with significant challenges, including the potential for acute and late recoil after stenting, high incidence of dissection and stent compression or under-expansion. Further, the drug technologies used in endovascular interventions may not be as efficacious going through a calcified wall, according to Sethi.
In this case, atherectomy has several potential benefits, he said. It can increase luminal diameter, decrease plaque burden and reduce calcification. The question is, however, whether the procedure is worth the time, risk for embolization and contrast radiation, among other issues.
“That’s ultimately what we’re trying to answer,” he said.
In looking at other technologies that can help facilitate calcium fracture without dissection, stents are a good option for bailout after dissection, according to Sethi. The primary patency rate hovers around 70% to 80% at 1 year, depending on the stent type, but when stents fracture, the primary patency drops to 40% at 1 year.
“We’ve all encountered patients who have a stent fracture, which puts them at risk for restenosis or thrombosis. This is because in the femoropopliteal segment, the stents are under incredible mechanical torsion, flexion and compression, so the thought may be that, with atherectomy, there may be a way to treat these lesions without stenting,” Sethi said.
Although there are a lot of registry and observational data, data from randomized trials are limited, according to Sethi. The DEFINITIVE AR and COMPLIANCE 360 trials, he noted, showed less dissection with atherectomy plus angioplasty vs. angioplasty alone. There were no other significant differences in outcomes between treatment groups in DEFINITIVE AR, but there was more freedom from target lesion revascularization in COMPLIANCE 360 with atherectomy plus angioplasty. However, both studies were small and underpowered, he said.
“We also know that drug delivery is very important to reduce the restenotic cascade. Once you have vessel injury, you have an inflammatory response and smooth muscle migration. Our drug technology does help restenosis, but we know that calcium reduces drug-coated balloon efficacy,” Sethi said.
For instance, he noted that in a study of 60 patients with superficial femoral artery stenosis or occlusion treated with drug-coated balloons, greater calcification was associated with lower patency, lower ankle brachial index, greater lumen loss and a higher target lesion revascularization rate at 1 year.
“If you have calcification, you’re going to inhibit the drug from going where it needs to go and will potentially have greater restenosis if you’re using a non-stent strategy,” he said.
In light of these data, one question is when to use atherectomy, according to Sethi.
“We use it in lesions that won’t dilate, when there’s heavy calcium, in long bulky disease and in ‘no’ stent zones,” he said. “Let’s say you’re doing a CFA intervention and the patient doesn’t want surgery for whatever reason. You may really want to limit dissection and therefore you may want to choose an atherectomy strategy with a balloon and potentially get away with less dissection.”
Sethi noted, however, that operators must consider a number of factors before forging ahead with atherectomy.
“In our practice, we try to assess how bad the calcium is and consider using IVUS liberally. We also believe in embolic protection and drug delivery and use atherectomy aggressively when we’re able to get a true lumen,” he said.
More judicious use
Wyers, who was tasked with arguing against liberal use of atherectomy, opened his presentation by noting that “there is no proof that it works.”
“Atherectomists talk a lot about vessel preparation — the necessity to beat the artery into submission before you apply the definitive treatment. They talk about low-pressure angioplasty being the goal and, although they agree low-pressure angioplasty is useful, it’s not really. You’re not being gentle to the artery. There is a lot of force by sanding the surface of the plaque or carving strips off that still injury the vessel,” he said. “Furthermore, more efficient drug delivery, which is a whole separate topic these days, may translate to even higher late mortality.”
Stent avoidance is also often cited as a reason for use of atherectomy, but Wyers said that argument may be less relevant now than it was in previous years when stents were shown to be “miserable performers.” Stent fracture remains a real issue, but stents have improved recently.
“Also, the strategy of ‘leave nothing behind’ is really designed to make your next intervention a little bit easier. That just belies the point. If you’re going to do that, no matter what we do, we’re going to be back,” Wyers said.
In terms of efficacy, one meta-analysis of four studies showed no difference in patency rates at 6 or 12 months with atherectomy vs. angioplasty. Additionally, data from Zilver PTX and In.PACT showed good patency data at 12 months with angioplasty alone.
“We’re doing pretty well, even without atherectomy based on these data,” he said.
Moreover, in DEFINITIVE LE, a trial that included 600 patients with claudication and 200 patients with critical limb ischemia, patency rates were lower at 1 year than in Zilver PTX and In.PACT, Wyers noted.
For the most part, according to Wyers, operators championing the use of atherectomy are “putting a lot of hope” into its use in combination with DEB technology. However, in DEFINITIVE AR, although the success rate was better in the atherectomy group, it came at a price.
“There was about a 6% incidence of distal embolization, which can be very unforgiving and hard to recover from. There was also about a 4% incidence of vessel perforation, so the technical success rate without a real patency benefit comes at the price of these complications,” he said.
There are also data that suggest that atherectomy may be associated with an increased risk for amputation, he added.
Financial incentives
Finally, the cost of atherectomy is extremely high, according to Wyers. After all, he noted, it is not just the cost of the device, but it’s the cost of an embolic protection device along with definitive treatment with a DCB or stent.
“The return on investment is in question here in terms of applying the technology that includes both an expensive device and an embolic protection device, without any real benefits in terms of lower reintervention rates and, I think, a higher risk of complications,” he said.
Wyers also discussed “the elephant in the room,” meaning financial incentives for performing atherectomy.
“If you look at the pricing of atherectomy and reimbursement, there’s a strong motivation because there is higher reimbursement in the outpatient vascular lab, so there may be a push to move these cases from non-atherectomy strategies to atherectomy strategies for financial reasons,” he said, noting that the number of atherectomy procedures recently increased significantly in outpatient labs but there has been minimal increase in its use in hospital or inpatient settings. “I would suggest that atherectomy would not be alive today were it not for the fact that it’s well-reimbursed in the outpatient vascular lab.”
However, Wyers noted he is not completely against the use of atherectomy.
“I use it as a tool to improve the initial technical success in very selected patients who are at high operative risk,” he said. – by Melissa Foster
Reference:
Sethi S. Great Debates in Vascular Intervention.
Wyers M. Great Debates in Vascular Intervention. Both presented at: American College of Cardiology Scientific Session; March 16-18, 2019; New Orleans.
Disclosures: Sethi and Wyers report no relevant financial disclosures.