1. Why choose an endovascular first strategy for patients with peripheral artery disease?
For patients with peripheral arterial disease, the mainstay of initial treatment is always risk factor modification, ambulation, and compliance with guideline-based medical therapies. However, for patients who have lifestyle limiting claudication or have progressed to critical limb ischemia (CLI), intervention is warranted.
Today, regardless of the specialty of the treating physician, endovascular management can be a suitable approach in almost all patients. As we well know, minimally invasive catheter-based therapies are associated with fewer complications, shorter recovery, and less discomfort than surgical bypass, with similar outcomes. We have a wide armamentarium of tools, improved short and long-term results compared to just a few years ago, and can treat increasingly smaller vessels in CLI patients. Catheter-based minimally invasive revascularization provides extraordinarily satisfying results and can routinely treat patients who are not surgical candidates.
2. Describe some of the challenges of endovascular procedures.
These patients often have multi-level disease, extraordinarily dense calcification, or long segment occlusions. Consequently, the mere physical act of passing our tools across these lengthy, complex, long-standing, and tortuous obstructions can be difficult and require unique skills and strategies for success
3. How does atherectomy help?
Atherectomy is used for patients with occlusive atherosclerotic disease in peripheral arteries and can help open their arteries by removing atherosclerotic plaque. Atherectomy is a major part of what we do to provide the best outcomes for our patients. The reason atherectomy is so important is that if you have areas of dense calcification, lesions may be difficult to cross, and balloons get constrained during inflation and may overstretch adjacent to calcified plaque, resulting in a “sausage-shaped” appearance during expansion. That often results in dissection and vessel failure, which occur more commonly at the margins of calcified lesions.
Atherectomy for vessel preparation allows us to make the vessel overall more uniform, so you get fewer dissections and better laminar flow and vessel caliber.
4. How is atherectomy different than other specialty balloons, such as scoring balloons or lithotripsy?
Atherectomy, unlike balloon angioplasty, has a unique ability to reduce intimal calcium. In addition, pulsatile waves and other forces generated in the media help to disrupt deeper calcium—which you simply can’t do with a specialty balloon. A specialty balloon, whether it be a scoring balloon, caged balloon, or some other design, may have advantages in controlling the balloon inflation and the interface with the vessel wall. But specialty balloons don’t impact the deeper calcium and the deeper disease within the vessel wall. These devices definitely have a role but don’t replace atherectomy.
5. What clinical data supports atherectomy as a treatment option for peripheral artery disease?
Each atherectomy device has its own body of evidence. Concerning the CSI® Diamondback 360® Peripheral Orbital Atherectomy System, the most recent study has been LIBERTY, which was actually three studies and included patients with claudication, Rutherford 4 and 5 patients with ischemic rest pain and minor tissue loss, and Rutherford 6 patients with major tissue loss or gangrene, which is the worst presentation of CLI.
Very few datasets have looked at Rutherford category 6, and these datasets are often excluded from evaluation in other trials. What’s amazing with the LIBERTY dataset is that a great majority of those patients—more than 80%—had successful revascularization and avoided major amputation.¹ Obviously, there is higher mortality in that group overall. But the fact is, in LIBERTY, the most complex disease pattern was shown not to be a factor that should dissuade interventionalists from proceeding with appropriate endovascular intervention.
6. Is atherectomy a cost-effective treatment option?
The idea of cost is always a complex one. Obviously, as physicians, we’re focusing on what’s best for the patient. We try not to let cost control our clinical decisions. But we understand the realities of the current medical climate. Drs. Mustapha and Shammas and others have done a deep dive and shown that atherectomy devices don’t actually cost more ²𝄒³. In fact, they may end up costing less because the biggest driver of cost to a patient, from a societal point of view, is either amputation—which is the costliest intervention and far more costly than any endovascular therapy—or reintervention.²
From a societal perspective, by utilizing atherectomy as part of an optimized angioplasty revascularization paradigm, we have the ability to get optimized results, a lower need for re-intervention and reduced amputations, all of which are extraordinarily cost-effective. Clearly, the best long-term outcomes for patients, regardless of initial expense, ultimately cost patients and payors the least.
¹ Mustapha JA, et al. One-Year Results of the LIBERTY 360 Study: Evaluation of Acute and Midterm Clinical Outcomes of Peripheral Endovascular Device Interventions. J Endovasc Ther. 2019 Apr;26(2):143-154.
² Mustapha JA, et al. Propensity Score-Adjusted Comparison of Long-Term Outcomes Among Revascularization Strategies for Critical Limb Ischemia. Circ Cardiovasc Interv. 2019 Sep;12(9):e008097.
³ Shammas NW, et al. Hospital cost impact of orbital atherectomy with angioplasty for critical limb ischemia treatment: a modeling approach. J Comp Eff Res. 2018 Apr;7(4):305-317.
Dr. Rundback is a paid consultant of CSI.
Brief Statement: The Diamondback 360® Peripheral Orbital Atherectomy System is a percutaneous orbital atherectomy system indicated for use as therapy in patients with occlusive atherosclerotic disease in peripheral arteries and stenotic material from artificial arteriovenous dialysis fistulae. Contraindications for the system include for use in coronary arteries, bypass grafts, stents, or where thrombus or dissections are present. Although the incidence of adverse events is rare, potential events that can occur with atherectomy include: pain, hypotension, CVA/TIA, death, dissection, perforation, distal embolization, thrombus formation, hematuria, abrupt or acute vessel closure, or arterial spasm.
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