Atherectomy
Atherectomy is a minimally invasive, catheter-based endovascular procedure employed to remove atherosclerotic plaque from the inner walls of arteries, thereby restoring luminal patency and improving blood flow in patients with peripheral artery disease (PAD) or coronary artery disease.[1][2] The technique involves specialized devices that mechanically excise, ablate, or vaporize plaque, distinguishing it from balloon angioplasty or stenting by directly debulking obstructive material rather than merely compressing it against the vessel wall.[3][4] Developed in the early 1980s as an alternative to emerging percutaneous transluminal angioplasty, atherectomy concepts originated with innovations like directional coronary atherectomy by John Simpson in 1984 and rotational atherectomy by David Auth around 1981, addressing limitations in treating fibrotic or calcified lesions.[5][6] Over subsequent decades, device evolution has yielded multiple FDA-approved systems, including rotational (e.g., Rotablator), orbital (e.g., Diamondback 360°), directional (e.g., SilverHawk), and excimer laser variants, each tailored to specific plaque morphologies such as calcification or thrombus.[4][7] Indicated primarily for complex, calcified, or diffusely diseased lesions where procedural success with conventional percutaneous coronary intervention (PCI) or angioplasty is compromised, atherectomy facilitates adjunctive therapies like drug-coated balloon angioplasty, potentially enhancing patency rates.[8][9] Clinical trials, such as the ORBIT II study for orbital atherectomy, demonstrate high acute procedural success (often exceeding 90%) in severely calcified coronary lesions, though long-term superiority over non-debulking strategies remains debated due to risks like vessel perforation, dissection, distal embolization, and no-reflow phenomena.[10][11][12] Evidence from randomized comparisons indicates no consistent reduction in target lesion revascularization or restenosis across all peripheral applications, underscoring its role as a selective rather than routine intervention guided by lesion-specific anatomy and operator expertise.[12][13]History
Origins and Early Development
The concept of atherectomy emerged in the early 1980s as a response to the limitations of percutaneous transluminal coronary angioplasty (PTCA), introduced by Andreas Grüntzig in 1977, which relied on plaque compression rather than removal and carried risks of elastic recoil and dissection.[14] John B. Simpson, a cardiologist at Stanford University, developed the first directional coronary atherectomy (DCA) device in 1984, inspired by a failed PTCA case and the mechanics of a Cope pleural biopsy forceps, enabling catheter-based excision of atherosclerotic plaque to debulk lesions selectively.[15] [5] The device featured a cylindrical housing with a cutting window and collectible housing for excised tissue, aiming to reduce restenosis rates compared to balloon dilation alone.[14] Initial human trials for DCA began following the filing of an Investigational Device Exemption with the FDA on October 21, 1986, marking the transition from preclinical testing to clinical evaluation.[16] Early procedures demonstrated feasibility in coronary arteries, with the first randomized trial incorporating DCA reported in 1987, showing procedural success in resecting plaque while preserving vessel architecture.[17] The FDA granted approval for the Simpson Atherocath in 1990 specifically for coronary applications, establishing DCA as the inaugural atherectomy modality in clinical practice.[18] Parallel to directional techniques, rotational atherectomy originated from biomedical engineer David Auth's work starting in 1981, utilizing a high-speed diamond-coated burr to ablate calcified plaque via microfractures rather than bulk excision.[15] The first successful human rotational procedure occurred in 1987, performed by Fourrier in France, addressing PTCA failures in heavily calcified lesions where directional methods proved less effective.[15] These early innovations laid the groundwork for atherectomy's evolution, prioritizing plaque debulking to enhance luminal gain and long-term patency, though initial enthusiasm tempered by restenosis challenges in subsequent trials.[19]Key Technological Advancements and Regulatory Milestones
The Simpson Coronary AtheroCath, the first directional atherectomy device for coronary applications, received FDA premarket approval (PMA P890043) in 1990, enabling targeted excision and collection of atherosclerotic plaque via a cutter housed in a metal housing with a balloon for lesion apposition.[20] This marked a pivotal regulatory milestone, shifting from balloon angioplasty alone by allowing debulking of eccentric lesions, though subsequent trials like CAVEAT revealed higher restenosis rates compared to percutaneous transluminal coronary angioplasty (PTCA).[21] Concurrently, the Rotablator rotational atherectomy system obtained FDA PMA (P900056) on August 28, 1990, introducing high-speed diamond-coated burr ablation (up to 200,000 rpm) to pulverize calcified plaque into microparticles, facilitating subsequent interventions in heavily calcified vessels.[22] Technological refinements over decades included smaller burr sizes (1.25–2.0 mm) and improved drive shafts for enhanced safety and efficacy in coronary use, addressing limitations like slow advancement and no tissue collection.[23] The excimer laser coronary atherectomy (ELCA) system achieved FDA approval in 1992, leveraging 308 nm ultraviolet light for photochemical vaporization of plaque with minimal thermal damage, particularly effective for thrombus-rich or fibrotic lesions.[24] This non-mechanical advancement expanded options for undilatable or no-reflow scenarios, with catheter sizes evolving to 0.7–2.0 mm diameters for small vessels and chronic total occlusions.[25] For peripheral artery disease, the SilverHawk peripheral plaque excision system secured FDA 510(k) clearance (K061188) on October 23, 2006, featuring a rotating blade that excises plaque into a nose cone for aspiration, improving luminal gain without distal embolization risks inherent in earlier directional devices.[26] This plaque excision technology represented a key evolution, with subsequent iterations like TurboHawk incorporating active tissue collection for below-the-knee applications.[4] Orbital atherectomy advanced with the Diamondback 360 Coronary Orbital Atherectomy System receiving FDA PMA (P130005) on October 22, 2013—the first new coronary atherectomy device in over two decades—utilizing a diamond-coated crown on an eccentric wire for bidirectional sanding at variable speeds (80,000–120,000 rpm), reducing vessel trauma compared to rotational methods.[27] Peripheral versions preceded this, cleared in 2011, emphasizing modifiable orbital diameters for calcified lesions.[28] Recent regulatory developments include the FDA's 2021 guidance on premarket notifications for peripheral vascular atherectomy devices, standardizing testing for safety and performance amid rising adoption, while device innovations like single-operator rotational systems (e.g., Rota-Pro) and orbital platforms with integrated aspiration (e.g., FreedomFlow, cleared 2023) address embolization and operator ergonomics.[29][30][31]Indications and Clinical Applications
Treatment of Coronary Artery Disease
Atherectomy is employed in the percutaneous treatment of coronary artery disease (CAD) to debulk or modify atherosclerotic plaque, particularly in heavily calcified lesions that resist standard balloon predilation or stent expansion. This approach enhances procedural success by improving vessel compliance and luminal gain, thereby reducing risks associated with underexpanded stents, such as stent thrombosis or restenosis. Rotational, orbital, and laser atherectomy devices are utilized, with indications centered on severe calcification confirmed by angiography or intravascular ultrasound (IVUS), often involving circumferential calcium exceeding 270 degrees or lesions refractory to conventional angioplasty. The 2011 ACC/AHA guidelines assign a Class IIa recommendation to rotational atherectomy for such calcified coronary lesions.[32][8][33] Clinical trials demonstrate high procedural efficacy, with rotational atherectomy achieving 92.5% success rates versus 83.3% in standard percutaneous coronary intervention (PCI) in the ROTAXUS trial, while orbital atherectomy reports 88.9-99% success and 90% freedom from 30-day major adverse cardiac events (MACE). Laser atherectomy yields 90-93.7% success, facilitating better stent apposition in complex lesions. These outcomes are attributed to effective plaque ablation, with rotational techniques providing superior modification in dense calcium compared to orbital methods, though direct head-to-head trials are limited. Long-term data indicate MACE rates of 16.7% at 12 months for orbital atherectomy and 29.4-34.3% at 2 years for rotational, comparable to non-atherectomy PCI in adjusted analyses, with reduced target lesion revascularization in calcified subsets when atherectomy is used.[8][32][33] Safety profiles reveal risks including coronary perforation (0-2%), dissection (1.7-5.9%), and slow/no-reflow (0-2.6%), which are minimized through burr-to-artery ratios of 0.4-0.7, short ablation runs under 20 seconds, and prophylactic pharmacotherapy like verapamil. Orbital atherectomy shows lower no-reflow incidence (<1%) due to its design, while laser methods carry dissection risks up to 2%. Operator expertise and adjunctive imaging are critical, as complications correlate with procedural volume; studies emphasize avoiding aggressive strategies to prevent burr entrapment (0.5-1%). Compared to emerging therapies like intravascular lithotripsy, atherectomy maintains equivalent efficacy but may involve longer procedure times and higher contrast use, underscoring its role as a targeted tool rather than routine therapy in non-calcified CAD.[33][32][8]Management of Peripheral Artery Disease
Atherectomy serves as an endovascular debulking strategy in the management of peripheral artery disease (PAD), particularly for lower extremity lesions characterized by heavy calcification, diffuse atherosclerosis, or in-stent restenosis, where percutaneous transluminal angioplasty (PTA) alone yields suboptimal luminal gain or high rates of dissection.[34] [13] By mechanically excising plaque via cutting, grinding, sanding, or lasing, atherectomy facilitates vessel preparation, enabling more effective adjunctive therapies such as drug-coated balloon (DCB) angioplasty or provisional stenting while potentially minimizing barotrauma from high-pressure balloons.[35] [36] Its utilization has risen to approximately 18% of all peripheral vascular interventions (PVIs) in the United States, reflecting adoption for complex femoropopliteal and infrapopliteal disease in patients with intermittent claudication or chronic limb-threatening ischemia (CLTI) refractory to guideline-directed medical therapy and supervised exercise.[36] [37] Indications prioritize hemodynamically significant lesions in aortoiliac, femoropopliteal, or tibial segments with Rutherford classification 2-4 (moderate to severe claudication) or higher in CLTI, especially where calcification impedes PTA compliance or risks elastic recoil.[38] The 2024 ACC/AHA guidelines for lower extremity PAD acknowledge atherectomy as one endovascular option among PTA, stenting, and intravascular lithotripsy for revascularization in claudication, with device selection guided by lesion morphology, operator expertise, and anatomy, though without assigning a specific class of recommendation or level of evidence.[37] Procedural success rates exceed 86% for residual stenosis below 50% with atherectomy alone, rising to 97% when combined with PTA, particularly beneficial in calcified lesions to enhance drug delivery from DCBs and reduce bailout stenting rates.[39] [40] Available devices include directional atherectomy (e.g., HawkOne system for selective plaque excision), rotational (e.g., Rotarex for combined thrombectomy and atherectomy), orbital (e.g., Diamondback 360 for centrifugal sanding of calcium), and excimer laser atherectomy for photoablation of thrombus-laden or calcified plaque.[35] [41] These are deployed percutaneously under angiographic guidance, often with embolic protection in high-risk cases, followed by adjunctive PTA or DCB to achieve optimal patency.[34] Midterm primary patency rates vary, with rotational atherectomy-assisted interventions reporting 97% at 12 months and 83% at 24 months in femoropopliteal disease, though secondary patency reaches 91-99%.[42] Clinical evidence remains limited by heterogeneous, mostly observational studies and small randomized controlled trials (RCTs), with a 2020 Cochrane review concluding very low-certainty data showing no significant differences in primary patency at 6 months (RR 1.06, 95% CI 0.94-1.20) or 12 months (RR 1.20, 95% CI 0.78-1.84) versus PTA, nor in mortality (RR 0.50, 95% CI 0.10-2.66 at 12 months).[43] Long-term outcomes indicate higher 5-year major adverse limb events (MALE) with atherectomy (38%) compared to PTA (33%) or stenting (32%), attributed to potential complications like distal embolization or perforation, though subgroup analyses in severely calcified lesions suggest reduced target lesion revascularization (TLR) and amputation rates with debulking prior to DCB.[44] [45] Rotational atherectomy may outperform directional in patency for PAD, but overall, atherectomy does not consistently demonstrate superiority over PTA alone in reducing restenosis or improving amputation-free survival, prompting selective use in expert centers for high-calcium burdens where it achieves median luminal gains of 26.4%.[46] [36] Larger RCTs are needed to clarify its role amid rising procedural volumes and costs.[47]Techniques and Devices
Directional Atherectomy
Directional atherectomy employs a specialized catheter system featuring a rotating cutter blade housed within a cylindrical device that includes an eccentrically positioned cutting window, allowing for targeted excision of plaque while minimizing damage to the vessel wall.[48] The cutter advances against the plaque, shaving it into a collection chamber or nose cone for removal, with the directional capability enabling orientation toward eccentric lesions via imaging guidance such as angiography or intravascular ultrasound.[49] This technique contrasts with non-directional methods by permitting selective debulking, which can achieve greater lumen gain in non-calcified or mixed plaques, though it requires manual device manipulation and carries risks of dissection or embolization if not precisely controlled.[46] Primary devices for peripheral applications include the SilverHawk peripheral plaque excision system and its successor, the HawkOne directional atherectomy system, both developed by Medtronic (formerly Covidien).[50][51] The SilverHawk, introduced in the mid-2000s, features varying catheter sizes for above-knee lesions, with a cutter speed of approximately 2,000 to 8,000 rpm and a collection nose cone to trap debris, reducing distal embolization rates compared to earlier designs.[48] The HawkOne, FDA-cleared on November 3, 2014, offers improved flexibility for below-knee use, with a dual-mode cutter (active and passive) and enhanced torque for tortuous anatomy, achieving procedural success rates exceeding 95% in trials like DEFINITIVE LE, where it demonstrated 89% freedom from target lesion revascularization at 12 months in claudicants.[52][53] In coronary applications, directional coronary atherectomy (DCA) historically utilized devices like the AtheroCath, but its use has declined due to higher complication rates in randomized trials such as the Balloon vs. Optimal Atherectomy Trial (BOAT) from 1998, which reported acute success rates of 87% but noted procedural complexity and no long-term superiority over angioplasty alone in subsequent analyses.[54][49] Current peripheral-focused iterations prioritize femoropopliteal and infrapopliteal disease, often combined with adjunctive therapies like drug-coated balloons to mitigate restenosis, as evidenced by meta-analyses showing reduced target lesion revascularization (odds ratio 0.62) when atherectomy precedes balloon angioplasty.[55] Procedural execution involves guidewire access, device advancement under fluoroscopy, multiple passes with window orientation toward plaque (typically 4-8 passes per lesion), and aspiration or filtration for debris management to limit embolization, which occurs in 2-5% of cases per observational data.[46] Comparative studies, such as those evaluating directional versus rotational atherectomy in peripheral artery disease, indicate directional methods yield equivalent acute lumen gains but potentially higher long-term restenosis in complex lesions, with 1-year patency rates of 78-85% in popliteal arteries versus 90% for rotational approaches.[56][46] Limitations include operator dependency, unsuitability for heavily calcified plaques (where rotational or orbital alternatives predominate), and the need for bailout stenting in 10-20% of procedures due to residual stenosis or dissection.[57]Rotational Atherectomy
Rotational atherectomy employs a high-speed rotating burr coated with diamond particles to ablate heavily calcified atherosclerotic plaque in coronary arteries, facilitating subsequent balloon angioplasty and stenting. The mechanism relies on differential cutting, where the burr, spinning at 140,000 to 200,000 revolutions per minute, selectively pulverizes inelastic calcified tissue while sparing compliant vascular elements, producing microparticles of 2 to 5 micrometers that are cleared via the reticuloendothelial system without causing distal embolization.[11][33] This approach modifies plaque to enable device delivery in lesions resistant to standard percutaneous coronary intervention (PCI).[32] The primary device is the Rotablator or RotaPro system (Boston Scientific), featuring burr sizes from 1.25 to 2.50 mm advanced over a specialized 0.009-inch RotaWire guidewire, with rotation driven by a helical shaft and controlled via a console for speed adjustment.[11][33] Procedural technique involves femoral or radial access (6-8 French sheaths), initial small-burr advancement (e.g., 1.25 mm), progressive upsizing by 0.25-0.50 mm to achieve a burr-to-artery ratio of 0.4-0.6 (maximum 0.7), short ablation runs of 15-20 seconds using a "pecking" motion, and continuous flushing with a heparinized saline solution containing verapamil, nitroglycerin, or RotaGlide lubricant to prevent vasospasm and heat buildup.[33][32] Speeds above 180,000 rpm are avoided to minimize thrombus risk.[32] Indications center on de novo, severely calcified coronary lesions—encountered in about 20% of PCI cases—particularly ostial, bifurcated, or chronic total occlusions where calcification impedes guidewire crossing or balloon expansion; it is used in fewer than 5% of overall PCIs but is contraindicated in soft, thrombotic, or degenerated saphenous vein graft lesions.[11][33] Procedural success exceeds 90-98% in undilatable lesions, with trials like ROTAXUS demonstrating reduced procedure time (19 minutes less), fluoroscopy exposure, and contrast use compared to non-atherectomy strategies, though long-term major adverse cardiac events are similar; the DIRO trial (n=100) showed superior plaque modification and stent expansion versus orbital atherectomy (99.5% vs. 90.6% modification area).[33][32] Earlier studies such as STRATAS and CARAT indicated no angiographic or clinical benefit from aggressive burr sizing (ratio >0.7), which instead raised complication rates.[33] Complications include slow/no-reflow phenomenon (0-7.6%, managed with vasodilators and fluids), coronary perforation (0-2%), dissection (1.7-10%), myocardial infarction (1.2-1.3%), death (1%), and rare burr entrapment (0.5-1%, requiring wire retrieval or surgery); overall severe event rates remain below 2% in expert hands, with operator experience (minimum 5 proctored cases) critical for safety.[11][33][32]Orbital Atherectomy
Orbital atherectomy employs a rotating, diamond-coated crown mounted eccentrically on a flexible drive shaft, which orbits at high speeds to ablate calcified atherosclerotic plaque within coronary or peripheral arteries.[58] The mechanism involves centrifugal force driving the crown against the vessel wall, sanding plaque into microparticles typically smaller than 2 μm, which are then emulsified and cleared via continuous antegrade blood flow without requiring distal protection devices.[59] This bidirectional orbital motion—achievable by simply reversing the drive shaft direction—enables treatment across a range of vessel diameters while maintaining luminal patency and minimizing thermal injury to the media.[32] The primary device for coronary applications is the Diamondback 360 Coronary Orbital Atherectomy System (OAS), approved by the U.S. Food and Drug Administration (FDA) on October 22, 2013, for facilitating stent delivery in patients with de novo, severely calcified coronary lesions.[60] [27] It features crowns of 1.25 mm or 1.5 mm diameter, operating at up to 120,000 rpm, with saline infusion to lubricate and cool the system.[61] For peripheral artery disease, variants like the Stealth 360 or extended-length Diamondback 360 systems (FDA-cleared as early as 2014 for lengths up to 60 cm) adapt similar principles for larger vessels, using crowns up to 2.5 mm at speeds of 40,000–80,000 rpm.[62] [63] Compared to rotational atherectomy, orbital atherectomy provides greater plaque modification in lesions with larger cross-sectional areas, produces finer particulate debris to reduce no-reflow risk, and supports noncalcified plaque ablation due to its orbital trajectory.[59] [64] Procedural technique typically involves advancing the device over a 0.014-inch guidewire, initiating ablation at lower speeds (e.g., 80,000–100,000 rpm coronarily) for 10–20 seconds per pass, with multiple passes at advancing positions to achieve luminal gain.[65] Operators monitor for complications like dissection or perforation, often confirmed via intravascular imaging such as optical coherence tomography.[66] Clinical adoption emphasizes its role in high-calcium burden cases refractory to balloon angioplasty, though randomized trials like ECLIPSE (reported 2024) indicate no superiority over conventional percutaneous coronary intervention for routine use in reducing target vessel failure at 1 year.[67]Laser and Excimer Atherectomy
Laser atherectomy employs ultraviolet excimer laser energy to ablate atherosclerotic plaque through photochemical, photothermal, and photomechanical mechanisms. The photochemical effect dissociates molecular bonds in plaque tissue via 308 nm wavelength pulses, while photothermal heating vaporizes cellular components, and photomechanical shockwaves from expanding gas bubbles fragment debris into particles smaller than 10 microns, minimizing distal embolization risk compared to mechanical atherectomy methods.[24][68][58] This approach targets organized thrombus, fibrotic tissue, and calcified lesions selectively, preserving elastic arterial components and reducing thermal injury to the vessel wall.[69] The primary device is the excimer laser coronary atherectomy (ELCA) system, manufactured by Philips (formerly Spectranetics), featuring over-the-wire catheters in diameters from 0.9 mm to 2.0 mm with eccentric or centered beam delivery.[70][71] Pulse repetition rates range from 25 to 80 Hz, with fluence settings up to 80 mJ/mm² adjusted for lesion type—higher for thrombus (60-80 Hz, 60 mJ/mm²) and lower for fibrocalcific plaque (25-40 Hz, 45 mJ/mm²).[70][72] Procedure involves advancing the catheter under fluoroscopy after guidewire placement, continuous saline infusion (2-4 mL/sec) to displace blood and prevent cavitation, and slow manual advancement (0.25-1 mm per pulse) to avoid vessel perforation.[71][68] It is typically adjunctive to percutaneous transluminal angioplasty (PTA) or stenting, with laser debulking reducing balloon pressure needs by 30-50% in underexpanded stents.[73] Indications include in-stent restenosis (ISR), stent underexpansion, heavily calcified or thrombotic lesions in acute coronary syndrome, saphenous vein graft disease, and chronic total occlusions (CTOs), applicable in both coronary and peripheral arteries.[74][75] In peripheral applications, the EXCITE ISR randomized trial (2014) demonstrated procedural success of 93.5% for femoropopliteal ISR with excimer laser plus PTA versus 82.7% for PTA alone, with lower target lesion revascularization at 6 months (67.7% vs 83.2%).[76][77] Coronary studies report technical success rates of 91-96.3%, outperforming rotational atherectomy (93.3%) in lesion crossing for calcified cases, though randomized data remain limited.[78][72] A 2025 analysis of 58 balloon-failure cases showed 91% success with ELCA over 4 years.[78] Complications occur in 5-10% of cases, including coronary perforation (0.9-2%), dissection (0.9-5%), slow/no-reflow (2-3%), non-Q-wave myocardial infarction (2.3%), Q-wave infarction (1%), and death (0.7%).[79][74] Risk doubles in CTOs due to increased energy delivery needs, but particle size reduces no-reflow incidence versus rotational or orbital atherectomy.[70][68] Saline flush interruption heightens dissection risk, and thrombus-rich lesions may provoke distal embolization if not managed with antiplatelet therapy.[24][80] Overall, excimer laser's precision suits complex lesions where mechanical methods fail, though operator experience critically influences outcomes.[73]Procedure Overview
Preoperative Preparation and Patient Selection
Patient selection for atherectomy prioritizes individuals with symptomatic coronary or peripheral artery disease featuring heavily calcified or fibro-calcific lesions that resist adequate expansion with conventional balloon angioplasty alone, as confirmed by intravascular imaging such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT) to assess plaque burden, calcium arc, and vessel compliance.[81] [82] Ideal candidates include those with diffuse calcification, ostial lesions, or long-segment disease where atherectomy facilitates stent deployment or luminal gain, particularly in patients deemed high-risk for alternative revascularization like bypass surgery due to comorbidities such as advanced age, diabetes, or prior myocardial infarction.[33] [83] Relative contraindications encompass thrombus-laden lesions, as atherectomy devices like rotational systems are ineffective and risk distal embolization in soft or acute thrombotic plaques; inability to advance a guidewire across the lesion; or target lesions within saphenous vein grafts or highly tortuous vessels, which increase procedural complexity and complication rates.[11] [84] In peripheral applications, selection extends to patients with critical limb ischemia or claudication refractory to medical therapy, emphasizing Rutherford class 2-5 disease with calcification unsuitable for drug-coated balloons or stenting alone, while excluding those with active infection or poor runoff vessels that preclude durable patency.[85] [86] Preoperative preparation begins with a comprehensive clinical evaluation, including detailed history, physical examination, and laboratory assessments to identify comorbidities such as renal insufficiency, coagulopathy, or contrast allergies that could elevate periprocedural risks, alongside optimization of antiplatelet or anticoagulant regimens—typically continuing aspirin while holding P2Y12 inhibitors like clopidogrel 5-7 days prior if feasible, to balance bleeding and thrombotic hazards.[1] [87] Diagnostic angiography or non-invasive imaging (e.g., CT angiography for peripheral cases) is mandated to delineate lesion anatomy, calcium distribution, and vessel caliber, guiding device selection and confirming procedural feasibility.[81] Patients are instructed to fast for at least 6-8 hours pre-procedure to mitigate aspiration risk under sedation, with adjustments for diabetics via insulin protocols; hydration protocols, especially with IV fluids or N-acetylcysteine, are employed for those with chronic kidney disease to prevent contrast-induced nephropathy.[88] [89] Informed consent emphasizes discussion of atherectomy-specific risks like perforation or no-reflow, distinct from standard percutaneous interventions, and multidisciplinary input from interventionalists, vascular surgeons, and cardiologists ensures alignment with patient-specific factors like frailty or hemodynamic stability.[33] [90] For coronary atherectomy, pre-procedure stress testing or fractional flow reserve may refine urgency, while peripheral cases often incorporate duplex ultrasound to evaluate inflow and outflow tracts.[37]Intraoperative Execution
Atherectomy procedures are conducted in a catheterization laboratory under fluoroscopic and angiographic guidance to ensure precise navigation and real-time visualization of arterial anatomy. Local anesthesia is applied at the vascular access site, supplemented by conscious sedation to maintain patient comfort without general anesthesia. Arterial access is established percutaneously, most commonly via the common femoral artery using a 6- to 8-French sheath, though radial access is increasingly utilized for coronary cases to reduce access-site complications.[91][11] Anticoagulation is initiated with intravenous unfractionated heparin, targeting an activated clotting time (ACT) exceeding 250-300 seconds to prevent thrombus formation during the intervention. Diagnostic angiography is performed through the guiding catheter to delineate the target lesion's location, severity, and calcium burden, confirming suitability for atherectomy. A 0.014-inch guidewire, often specialized (e.g., RotaWire for rotational or orbital systems), is advanced across the lesion under fluoroscopy to provide a rail for device delivery, with care taken to avoid wire bias or perforation.[91][11][32] The atherectomy device is then advanced over the guidewire to the lesion site. Activation varies by modality: rotational atherectomy employs a diamond-coated burr rotating at 140,000-190,000 revolutions per minute to ablate calcified plaque into microparticles, with continuous saline infusion to mitigate heat and entrapment risks; orbital systems use a crown oscillating at up to 120,000 rpm for eccentric plaque modification; directional devices excise tissue via a cutting window; and laser atherectomy delivers excimer ultraviolet energy to vaporize plaque. Multiple short passes (typically 10-20 seconds each) are executed, advancing 1-2 mm at a time while monitoring for hemodynamic stability, electrocardiographic changes, or slow/no-reflow phenomena indicative of distal embolization. Debris capture mechanisms, such as aspiration ports or embolic protection filters (more routine in peripheral applications), are employed to minimize downstream occlusion.[11][91][32] Post-atherectomy, the device is withdrawn, and adjunctive balloon angioplasty is performed to further expand the lumen, often followed by drug-eluting stent deployment to scaffold the vessel and prevent recoil. Final angiography evaluates procedural success, targeting residual stenosis below 20-30% with Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in coronary cases. Throughout, vital signs, including blood pressure and heart rhythm, are continuously monitored, with temporary pacing available for high-risk coronary lesions to manage bradycardia from vagal stimulation or burr entrapment.[11][32][33]Postoperative Management and Follow-Up
Following atherectomy, patients are typically monitored in a recovery area or catheterization laboratory for several hours to assess for immediate complications such as bleeding, hematoma formation, or hemodynamic instability.[1] Bed rest with the affected leg or arm immobilized is enforced for 4-6 hours to facilitate hemostasis at the arterial access site, during which vital signs including blood pressure, pulse, and heart rate are continuously tracked.[1] Local pressure is applied to the insertion site, and ice packs may be used intermittently to reduce swelling, with a pressure dressing maintained for 24-48 hours.[92] Pharmacotherapy forms a cornerstone of postoperative management, with dual antiplatelet therapy (e.g., aspirin combined with clopidogrel or ticagrelor) initiated or continued for at least 6-12 months in coronary atherectomy cases to mitigate stent thrombosis risk, particularly when stenting follows atherectomy.[93] Adjunctive medications such as statins for lipid control and antihypertensives are optimized to address underlying atherosclerosis drivers.[94] Pain at the access site is managed with analgesics, expected to resolve within days, while anticoagulation may be bridged if preoperative therapy was paused.[94] Patients are generally discharged within 24 hours if stable, with instructions to avoid strenuous activity, heavy lifting (>10 pounds), or prolonged standing for 1-2 weeks to prevent access-site complications.[95] Wound care involves daily cleaning of the insertion site without rubbing, monitoring for signs of infection (e.g., redness, fever >100.4°F), and reporting symptoms like excessive bleeding, chest pain, or limb ischemia promptly.[96] Follow-up entails an initial clinic visit within 7-10 days to evaluate the access site, assess medication adherence, and perform basic vascular checks such as ankle-brachial index (ABI) for peripheral cases or electrocardiography for coronary procedures.[2] Subsequent appointments occur at 1 month, then every 3-6 months, incorporating noninvasive imaging like duplex ultrasonography to detect restenosis, with exercise stress testing or angiography reserved for symptomatic recurrence.[93] Long-term surveillance emphasizes lifestyle modifications, including supervised exercise programs, to sustain patency rates, as empirical data indicate reduced reintervention with structured follow-up.[97]Efficacy and Evidence Base
Short-Term Procedural Outcomes
Procedural success in atherectomy is typically defined as achieving residual stenosis below 30% without major periprocedural complications such as perforation or the need for emergency bailout surgery.[98] In coronary applications, rotational atherectomy yields procedural success rates of 93.3% to 98%, with device delivery and plaque ablation facilitating subsequent interventions like stenting.[78][98] Laser atherectomy demonstrates slightly higher success at 96.3%, attributed to enhanced lumen gain (mean increase of 6.71 mm² versus -27.90 mm² for rotational, though the negative value reflects measurement context in comparative studies).[78] Periprocedural complications remain low across techniques, with overall rates around 1-2% for major events like death or myocardial infarction in coronary cases.[78] Rotational atherectomy reports comparable complication profiles to laser atherectomy (1.5% versus 1.2%), showing no significant differences.[78] Distal embolization occurs in 5-6% of rotational procedures, often resolving without further intervention, while vessel dissection and perforation rates are minimized through operator experience and lesion selection.[98] In peripheral artery disease, particularly femoropopliteal lesions, rotational atherectomy achieves procedural success in 98.8% of cases and lesion success in 96.6%, with no bailout stenting required in most instances.[98] Meta-analyses indicate no excess periprocedural risks compared to balloon angioplasty alone, including similar rates of distal embolization and technical success in infrapopliteal disease.[99] Provisional stenting rates remain low across atherectomy device classes, suggesting effective plaque debulking without heightened safety concerns.[100]Long-Term Clinical Results and Comparative Studies
Long-term clinical outcomes of atherectomy vary by vessel type, device, and lesion characteristics, with studies reporting patency rates and event-free survival influenced by calcification severity and adjunctive therapies. In peripheral artery disease (PAD), a 2023 meta-analysis of randomized trials found that atherectomy combined with balloon angioplasty (BA) reduced clinically driven target lesion revascularization (CD-TLR) at 12 months (odds ratio 0.53, 95% CI 0.34-0.82) and target limb major amputation or revascularization at 6-12 months compared to BA alone, though overall major adverse limb events (MALE) showed no significant difference.[99] For coronary applications, rotational atherectomy (RA) in calcified lesions demonstrated 3-year freedom from target vessel failure around 80-85% in observational cohorts, but with elevated risks of major adverse cardiac events (MACE) including myocardial infarction and revascularization compared to non-atherectomy percutaneous coronary intervention (PCI), particularly in patients with reduced left ventricular ejection fraction.[101][102] Orbital atherectomy in PAD yielded 3-year freedom from major amputation of approximately 90% in critical limb ischemia patients, with sustained symptom relief in claudication cases, though restenosis remained a concern without drug-coated adjuncts.[103] Comparative studies highlight atherectomy's role in complex lesions but question broad superiority over simpler endovascular options. In femoropopliteal PAD, a 2020 analysis of over 1,000 procedures showed no significant difference in 2-year MALE rates between atherectomy (38%) and plain old balloon angioplasty (POBA, 33%) or stenting (32%), with atherectomy associated with higher procedural costs and perforation risks.[44][104] Rotational atherectomy outperformed directional atherectomy in PAD for 12-month primary patency (75% vs. 62%) and reduced TLR, attributed to more uniform plaque ablation and lower dissection rates.[46] In coronary PCI, RA facilitated stent delivery in heavily calcified lesions with comparable 1-year MACE to non-RA PCI in registries (9-10%), but meta-analyses indicate increased long-term mortality and bleeding risks versus balloon-based predilation alone, possibly due to periprocedural microvascular injury.[105][102] Network meta-analyses of PAD interventions at 1 year found atherectomy plus drug-coated balloon similar to intravascular lithotripsy for vessel preparation but without clear patency advantages over POBA with coatings in non-calcified disease.[106]| Study Type | Intervention | Key Long-Term Endpoint (e.g., 1-3 Years) | Comparison | Outcome |
|---|---|---|---|---|
| Meta-analysis (PAD) | Atherectomy + BA | CD-TLR reduction | vs. BA alone | OR 0.53 (favoring atherectomy)[99] |
| Registry (PAD) | Atherectomy | MALE rate | vs. POBA/stenting | 38% vs. 33-32% (no difference)[44] |
| Observational (Coronary RA) | RA in calcified lesions | MACE/TVR | vs. non-RA PCI | Higher MACE risk[102] |
| Comparative (PAD devices) | Rotational vs. directional | Primary patency | Direct | 75% vs. 62% (favoring rotational)[46] |