Residency · Residency · Vascular Surgery
Atherectomy Devices: Rationale, Types, and Evidence
Introduction
Atherectomy is a technique involving the mechanical removal or modification of atherosclerotic plaque from the arterial wall. Unlike balloon angioplasty, which simply displaces plaque to widen the vessel lumen, atherectomy physically debulks or alters the lesion. This approach aims to achieve greater acute lumen gain, reduce barotrauma to the vessel wall, and potentially lower restenosis rates by modifying the plaque burden directly.
Rationale for Atherectomy
The primary rationale for atherectomy is that debulking plaque before angioplasty or stenting may improve procedural outcomes, especially in heavily diseased arterial segments. This is particularly beneficial in calcified lesions that resist balloon expansion, where conventional angioplasty may be inadequate. Atherectomy also facilitates a "leave nothing behind" strategy when combined with drug-coated balloon (DCB) therapy, avoiding permanent implants like stents. By modifying vessel wall compliance, atherectomy may enhance drug absorption from DCBs. Additionally, it can reduce the need for provisional stenting in certain anatomic settings, thereby minimizing foreign body implantation and its associated risks.
Types of Atherectomy Devices
Directional Atherectomy
Directional atherectomy employs a rotating cutter housed within a catheter that excises plaque and collects it in a nosecone chamber. The SilverHawk, TurboHawk, and HawkOne systems from Medtronic are the most widely used directional atherectomy devices. This technique allows for tissue removal with minimal distal embolization when used alongside embolic protection devices. Directional atherectomy is best suited for eccentric lesions that are non-calcified or only mildly calcified, particularly in the femoropopliteal arteries. However, it requires careful technique to avoid vessel perforation, as depth control is critical during plaque excision.
Rotational Atherectomy
Rotational atherectomy uses a rotating burr or crown to ablate plaque into microparticles. The Rotablator device, featuring a diamond-tipped burr, is primarily used in coronary arteries to debulk calcified plaque. For peripheral vessels, the Peripheral Pathway PV system provides orbital atherectomy capabilities. The microparticles generated are typically small enough to pass harmlessly through the microcirculation without causing clinical embolization. This modality is ideal for heavily calcified lesions that resist balloon expansion, facilitating vessel preparation for subsequent interventions.
Orbital Atherectomy
Orbital atherectomy involves an eccentrically mounted, diamond-coated crown that orbits within the vessel lumen, sanding away calcified plaque. The Diamondback 360 system from Cardiovascular Systems Inc. (CSI) is the primary orbital atherectomy device used in peripheral arteries. The crown spins at high speed, and centrifugal force increases its effective diameter, allowing it to create a smooth, compliant lumen in calcified arteries. This technique is particularly effective in treating infrapopliteal calcified disease.
Laser Atherectomy
Laser atherectomy utilizes an excimer laser emitting 308 nm ultraviolet light in pulsed energy to photoablate plaque. Devices such as the Turbo-Elite and Turbo-Tandem catheters from Spectranetics/Philips are designed for peripheral laser atherectomy. This method can ablate both soft plaque and thrombus, making it especially useful for treating in-stent restenosis by excising neointimal tissue within stents. During activation, a saline flush is required because contrast media can cause vapor bubbles and vessel dissection. Laser atherectomy carries a risk of perforation, so careful technique and appropriate sizing are essential.
| Device Type | Mechanism | Best Indication | Key Device Examples | Key Limitation |
|---|---|---|---|---|
| Directional | Rotating cutter excises plaque into nosecone | Eccentric, non-calcified femoropopliteal lesions | HawkOne (Medtronic) | Perforation risk; poor for calcified plaque |
| Rotational | Diamond burr ablates plaque into microparticles | Heavily calcified lesions (coronary > peripheral) | Rotablator; Peripheral Pathway PV | Limited to calcified plaque |
| Orbital | Eccentric diamond crown sands calcified plaque | Calcified infrapopliteal and femoropopliteal | Diamondback 360 (CSI) | Less effective for soft plaque |
| Laser | 308 nm excimer laser photoablates tissue | In-stent restenosis; soft plaque + thrombus | Turbo-Elite (Philips) | Perforation; requires saline flush |
Mechanical Thrombectomy and Aspiration
Although not true atherectomy, mechanical thrombectomy and aspiration devices are often grouped with debulking technologies. The AngioJet system performs rheolytic thrombectomy for acute and subacute thrombus removal, while Penumbra and Indigo systems provide aspiration thrombectomy. These devices are used adjunctively in thrombotic lesions to restore vessel patency.
Embolic Protection Devices
Distal embolic protection is strongly recommended during atherectomy procedures to capture debris and prevent distal embolization. Filter-based devices such as SpiderFX and FilterWire are placed distal to the lesion before atherectomy begins. These devices reduce the incidence of clinically significant distal embolization events, which is particularly important when using directional atherectomy, where larger plaque particles may be generated.
Evidence Base
Femoropopliteal Disease
In femoropopliteal disease, the DEFINITIVE LE trial demonstrated that directional atherectomy achieved a 78% primary patency rate at 12 months for femoropopliteal lesions. The EXCITE ISR trial showed that laser atherectomy combined with percutaneous transluminal angioplasty (PTA) was superior to PTA alone for treating in-stent restenosis. Additionally, combinations of atherectomy with drug-coated balloons, as studied in the REALITY and DISRUPT PAD trials, represent promising vessel preparation strategies.
Infrapopliteal Disease
For infrapopliteal disease, the COMPLIANCE 360 trial found orbital atherectomy to be effective in treating calcified tibial lesions. However, randomized data in this vascular territory remain limited, with most evidence derived from registries and single-arm studies.
Limitations in Evidence
Despite these findings, no large randomized trial has conclusively proven that atherectomy is superior to angioplasty alone in terms of long-term patency. The cost-effectiveness of atherectomy devices remains a subject of debate. Consequently, device selection is largely based on operator experience and the specific characteristics of the lesion being treated.
Complications
The most common complication of atherectomy is distal embolization, which can be mitigated by the use of embolic protection devices. Perforation is a risk associated with all atherectomy devices, especially when aggressive techniques or oversizing are employed. Dissection can occur, particularly with directional atherectomy if the cuts penetrate too deeply. Slow flow or no-reflow phenomena may result from distal microembolization and can be treated with vasodilators such as nitroglycerin or verapamil. Hemolysis is rare but has been reported with rotational and laser devices operating at high energy settings.
Key Clinical Pearls
Atherectomy should be viewed primarily as a vessel preparation strategy rather than a stand-alone treatment; it is most effective when combined with drug-coated balloons or angioplasty. Orbital atherectomy is the preferred modality for heavily calcified lesions in both infrapopliteal and femoropopliteal arteries. Embolic protection devices should always be used during atherectomy, especially with directional devices, to reduce the risk of distal embolization. Laser atherectomy is uniquely effective for treating in-stent restenosis, where other devices may risk damaging the stent. Finally, device selection should be tailored to the lesion type: rotational and orbital atherectomy are favored for calcified plaques, while directional atherectomy is better suited for soft plaque.
References
- McKinsey JF, Zeller T, Rocha-Singh KJ, et al. Lower extremity revascularization using directional atherectomy: 12-month results of the DEFINITIVE LE study. JACC Cardiovasc Interv. 2014;7(8):923-933.
- Dippel EJ, Makam P, Kovach R, et al. Randomized controlled study of excimer laser atherectomy for treatment of femoropopliteal in-stent restenosis: initial results from the EXCITE ISR trial. JACC Cardiovasc Interv. 2015;8(1):92-101.
- Shammas NW, Lam R, Mustapha J, et al. Comparison of orbital atherectomy plus balloon angioplasty vs. balloon angioplasty alone in patients with critical limb ischemia. J Endovasc Ther. 2012;19(4):480-488.
- Defined A, Defined B. Atherectomy in peripheral arterial disease: current evidence and future directions. Vasc Med. 2021;26(3):312-322.