Residency · Residency · Interventional Radiology

Atherectomy: Devices, Indications, and Evidence

Overview

Atherectomy is the mechanical removal or modification of atherosclerotic plaque from the arterial wall. The rationale behind the technique is to debulk plaque before angioplasty or stenting, thereby improving acute lumen gain and potentially reducing restenosis. Multiple device categories exist, each operating through a different mechanism of action. Despite decades of use, atherectomy remains one of the most controversial topics in interventional radiology and vascular surgery.

Device Categories

Directional Atherectomy

Directional atherectomy works by excisional cutting of plaque using a rotating blade housed in a windowed catheter. The primary devices in this category are the SilverHawk, TurboHawk, and HawkOne (Medtronic). The catheter is advanced across the lesion, the blade is activated and slowly withdrawn, shaving plaque into a nosecone collection chamber. Multiple passes at different orientations are performed to achieve circumferential debulking. The advantages include tissue removal (specimens can be sent for pathology), effectiveness for eccentric lesions, and good results for in-stent restenosis. The disadvantages are a risk of perforation, especially with aggressive passes, and distal embolization, which necessitates the use of a distal embolic protection device such as the Spider or Emboshield. This device is best applied to eccentric plaque, in-stent restenosis, and lesions at the popliteal artery or common femoral artery where stenting is undesirable.

Rotational Atherectomy

Rotational atherectomy uses a rotating burr or crown that sands plaque into microparticles. The Peripheral Rotablator features a diamond-coated burr on a drive shaft that generates particles smaller than 10 microns, which pass harmlessly through the capillary bed. The Pathway PV (Phoenix) uses a rotating cutting element with aspiration and collects debris. The Jetstream (Boston Scientific) is a rotating, aspirating atherectomy catheter effective for both thrombus and plaque. Rotational devices work well for heavily calcified lesions, and the microparticles are less likely to cause clinically significant distal embolization. However, drawbacks include vessel spasm, thermal injury to the vessel wall, and limited plaque removal volume per pass.

Orbital Atherectomy

Orbital atherectomy uses an eccentrically mounted diamond-coated crown that orbits within the vessel, preferentially sanding hard calcified tissue through a principle known as differential sanding. Softer, compliant tissue deflects away from the crown rather than being abraded. The primary device is the Diamondback 360 (CSI), which creates microparticles similar to rotational atherectomy. Its advantages include compliant tissue preservation and effective calcium modification, while its disadvantages include limited data in peripheral arteries, slow plaque removal, and a risk of hemolysis.

Laser Atherectomy

Laser atherectomy employs an excimer laser that delivers ultraviolet light at a 308 nm wavelength, photoablating tissue through photothermal, photochemical, and photomechanical mechanisms. The Turbo-Elite and Turbo-Tandem devices (Philips) are the principal platforms. The laser catheter is advanced slowly at approximately 1 mm per second through the lesion, with energy delivered in a pulsed fashion and a saline flush required to prevent thermal injury. Laser atherectomy is particularly effective for in-stent restenosis, where it ablates neointimal tissue, and can also assist in crossing some chronic total occlusions and debulking thrombus. However, it is expensive, carries a risk of perforation especially in small vessels, removes limited plaque volume, and requires special training. Its unique applications include treatment of failed PTFE bypass graft stenosis and CTO crossing.

Embolic Protection Devices

Distal embolization occurs in 2 to 10 percent of atherectomy procedures at a clinically significant level. Filter-based devices such as the Spider (Medtronic) and Emboshield NAV6 are deployed distal to the lesion to capture embolic debris. Their use is recommended with directional atherectomy and is required at many institutions. Deployment is not always feasible in infrapopliteal vessels or when the distal landing zone is limited.

Evidence and the Controversy

Arguments FOR Atherectomy

Plaque modification prior to drug-coated balloon (DCB) therapy may improve drug uptake and distribution, a concept explored in the DEFINITIVE AR study. Atherectomy can reduce the need for stenting in femoropopliteal disease, helping to avoid placing metal in the superficial femoral artery. It is especially useful in anatomic locations where stenting is undesirable, such as the common femoral artery, the popliteal region, and across the knee joint. For in-stent restenosis, atherectomy combined with DCB may outperform DCB alone, as suggested by the EXCITE ISR trial, which showed a benefit for laser plus PTA over PTA alone.

Arguments AGAINST Atherectomy

No randomized controlled trial has demonstrated superior long-term patency of atherectomy over PTA alone or PTA with stenting. Procedural costs are higher due to device cost, embolic protection device use, and longer procedure times. Complication rates, including distal embolization and perforation, tend to be higher compared with PTA alone. The DEFINITIVE LE study showed reasonable patency but lacked a PTA-only control arm, limiting its conclusions. Concerns about overutilization driven by financial incentives are significant, as atherectomy carries higher reimbursement. Medicare data analyses have shown dramatic increases in atherectomy use without corresponding improvements in amputation rates.

Key Studies

The DEFINITIVE LE study was a single-arm evaluation of directional atherectomy that showed 78 percent primary patency at 12 months in femoropopliteal lesions, but the absence of a control arm limits the conclusions that can be drawn. The DEFINITIVE AR study showed that atherectomy prior to DCB improved angiographic outcomes compared with DCB alone, though it was a small, hypothesis-generating study. The EXCITE ISR trial randomized patients with femoropopliteal in-stent restenosis to laser atherectomy plus PTA versus PTA alone and found that the laser group had higher freedom from target lesion revascularization at six months (73.5 percent versus 51.8 percent). The COMPLIANCE 360 study demonstrated that orbital atherectomy for calcified femoropopliteal disease improved subsequent balloon angioplasty outcomes through calcium modification.

Atherectomy in Specific Settings

Common Femoral Artery

The common femoral artery is traditionally surgical territory, with endarterectomy being the standard approach. However, directional atherectomy is gaining acceptance as a less-invasive alternative for CFA stenosis. TASC D CFA disease is still likely best treated surgically, and this remains an active area of research, with the ACTA trial ongoing.

Popliteal Artery and Across the Knee

Stenting across the knee joint is problematic due to the risk of stent fracture. Atherectomy combined with DCB is an attractive option for avoiding metal in this location. Data is limited but clinical experience is growing.

Infrapopliteal Arteries

Infrapopliteal vessels are small, typically 2 to 4 mm in diameter, making atherectomy technically feasible but high-risk. Orbital and directional atherectomy can be used for calcium modification before PTA, though the evidence base consists mostly of small case series.

In-Stent Restenosis

Directional atherectomy and laser atherectomy are the most commonly used devices for in-stent restenosis. Debulking neointimal hyperplasia before DCB application is a logical strategy. Some data, including the EXCITE ISR trial, supports this approach, but larger trials are needed.

<image>Comparison illustration of four atherectomy device mechanisms. Four panels: (1) Directional atherectomy (HawkOne) showing a windowed catheter with a rotating blade excising plaque into a nosecone collection chamber, with arrows indicating blade direction and plaque collection; (2) Rotational atherectomy showing a diamond-coated burr spinning at high speed and creating microparticles; (3) Orbital atherectomy (Diamondback 360) showing an eccentrically mounted diamond crown orbiting within the vessel, preferentially sanding calcified plaque; (4) Excimer laser atherectomy showing ultraviolet light pulses photoablating tissue with a saline medium. Each panel includes a cross-sectional inset showing the plaque before and after treatment.</image>

<image>Illustration of directional atherectomy with distal embolic protection for a superficial femoral artery lesion. Sequential panels showing: (1) Pre-procedural angiogram with eccentric calcified plaque; (2) Distal filter-type embolic protection device (Spider) deployed downstream; (3) HawkOne catheter making multiple passes at different clock positions to debulk plaque; (4) Magnified view of the filter basket containing captured plaque debris after retrieval; (5) Post-atherectomy angiogram with improved lumen followed by drug-coated balloon angioplasty. Labels highlight the filter, catheter window, cutting blade, and nosecone.</image>

<image>Bar graph comparing 12-month primary patency and complication rates across different atherectomy modalities and standard PTA. The graph shows grouped bars for directional, rotational, orbital, and laser atherectomy alongside plain PTA and DCB. Patency rates and rates of distal embolization, perforation, and target lesion revascularization are displayed. A cost comparison row at the bottom shows relative procedural costs. Data is annotated with references to key trials (DEFINITIVE LE, EXCITE ISR, COMPLIANCE 360).</image>

Clinical Pearls

No atherectomy device has proven superiority over PTA with stenting in rigorous randomized controlled trials, so the technology should be used judiciously and for specific indications. The best indications include CFA disease where stenting should be avoided, in-stent restenosis, popliteal and across-the-knee lesions, and calcium modification before DCB application. Distal embolic protection should always be used with directional atherectomy in the femoropopliteal segment. Atherectomy is a tool rather than a standalone therapy; it should be combined with DCB or PTA for definitive treatment. The financial incentives controversy is important to understand, as high reimbursement may drive overuse. Ultimately, the best outcomes come from thoughtful patient and lesion selection rather than device selection alone.

References

• McKinsey JF et al. Optimal endovascular treatment for femoropopliteal disease: DEFINITIVE LE results. J Vasc Surg 2014
• Dippel EJ et al. Randomized controlled study of excimer laser atherectomy for treatment of femoropopliteal in-stent restenosis (EXCITE ISR). JACC Cardiovasc Interv 2015
• Defined by the Defined by the SIR Position Statement on Atherectomy. J Vasc Interv Radiol 2019
• Defined by the ESVS Guidelines on the Management of PAD 2024
• Defined by the CMS Medicare claims analysis of atherectomy utilization trends

Read this lecture as Markdown