Atherectomy, Thrombectomy, and Distal Protection Devices

Karim M. Al-Azizi, MD

Aaron Kugelmass, MD

ATHERECTOMY, THROMBECTOMY, AND DISTAL PROTECTION DEVICES

Coronary artery disease is traditionally treated using balloon angioplasty and stenting. However, as the complexity of the disease increases, additional equipment may be needed to ensure success and minimize complications. This may include lesion modification, thrombus removal, or trapping lesion debris produced during the intervention to prevent distal embolization (FIGURE 19.1).

Atherectomy

Atherectomy has been a growing technique and is used primarily for lesion modification and debulking to improve stent delivery and expansion. The following section outlines the different atherectomy devices and techniques available with cases (FIGURES 19.2, 19.3, 19.4, 19.5, 19.6, 19.7, 19.8, 19.9, 19.10 and 19.11).

Thrombectomy

Myocardial infarction is most often the result of plaque rupture and subsequent intracoronary thrombus formation. Attempting percutaneous coronary intervention (PCI) on vessels with large thrombi has been associated with embolization, no-reflow phenomenon, and abrupt vessel closure. The following section outlines available thrombectomy techniques (FIGURES 19.12, 19.13, 19.14 and 19.15).

Embolic Protection

During coronary interventions, fragments of plaque or thrombus may embolize into the distal circulation resulting in no reflow and increased periprocedural myocardial injury. The following section outlines the use of embolic protection devices during PCI (FIGURES 19.16 and 19.17).

FIGURE 19.1 Atherectomy, thrombectomy, and distal protection devices. The figure illustrates the equipment that may be used in treating complex coronary artery disease. A, Medtronic Export AP aspiration thrombectomy catheter is seen in the left panel. B, Boston Scientific Rotablator System is seen in the right panel. C, A SpiderFX filter is seen in the bottom panel. A and C, Used with permission by Medtronic ©2018; B, Image provided courtesy of Boston Scientific. ©2018 Boston Scientific Corporation or its affiliates. All rights reserved.

FIGURE 19.2 A and B, Calcified coronary lesions. This figure illustrates significant coronary calcification (arrow) that can be encountered during cardiac catheterization and PCI. Atherectomy can modify the arterial wall compliance in heavily calcified vessels. This is accomplished both by plaque removal and micro fracturing of the vessel calcification. The net result is improved stent delivery and expansion.¹

FIGURE 19.3 Types of atherectomy devices and device characteristics. Atherectomy is indicated to facilitate stent delivery and improve stent expansion in patients with coronary artery disease who are acceptable candidates for coronary stenting owing to de novo, severely calcified coronary lesions. There are currently 2 types of atherectomy devices used in coronary interventions. A and B, The Boston Scientific Rotablator, which functions as rotational atherectomy. C and D, The Cardiovascular Systems, INC (CSI) Diamondback 360 is another device, which is a coronary orbital atherectomy system (seen in the bottom panel). These systems have a different atherotome shapes and drive systems. The Boston Scientific RotaLink catheter consists of an elliptical, nickel-coated burr, with a distal surface embedded with 20 µm diamond chips, protruding 5 µm from the surface. The CSI Diamondback device consists of a diamond-coated 1.25 mm crown, mounted on an asymmetric platform. A and B. Image provided courtesy of Boston Scientific. ©2018 Boston Scientific Corporation or its affiliates. All rights reserved; C and D. ©2018 Cardiovascular Systems, Inc. CSI®, Diamondback 360®, GlideAssist®, ViperWire Advance® and ViperSlide® are registered trademarks of Cardiovascular Systems, Inc., and used with permission.

FIGURE 19.4 Rotational atherectomy. Rotablator system burr mounted on a drive shaft and sheath. The burr size is usually selected based on a vessel to burr ratio of approximately 0.7, as demonstrated in the CARAT study (Coronary Angioplasty and Rotablator Atherectomy Trial).² In that study, there were higher rates of acute complications if higher burr to artery ratios were used, with no clear benefit or change in target vessel revascularization.

FIGURE 19.5 Rotational atherectomy. The RotaWires are designed specifically for the use with the rotational atherectomy system. They are made of a 0.009″ stainless steel core with tapered distal ends for varying degrees of burr support. A 0.014″ distal platinum coil prevents the burr from traveling beyond the tip of the wire. Image provided courtesy of Boston Scientific. ©2018 Boston Scientific Corporation or its affiliates. All rights reserved.

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