Embolic Protection DevicesEmbolic Protection Devices

Sripal Bangalore, M.D., M.H.A.and

Deepak L. Bhatt, M.D., M.P.H., F.A.H.A.

OverviewOverview

Embolic Protection Devices (EPDs) Rationale for use

Types of EPDs

Indications Vein graft intervention

Other indication

Equipment

Technique

Rationale for UseRationale for Use Manipulation of atherosclerotic lesions (with wires, balloons,

atherectomy catheters and stents) releases plaque debris

Plaque debris leads to no/slow flow as a result of: Obstruction of macro and microvascular channels

Promotion of local platelet adhesion/thrombosis (by releasing tissue factors)

Promotion of microvascular spasm (by releasing thromboxane)

Clinical manifestation of distal embolization depends on the amount of debris, size of particles and sensitivity of perfused organ

Coronary circulation (especially vein grafts): Ischemia/infarction

Cerebral circulation: TIA/stroke

EPDs prevent/reduce plaque debris from reaching the distal bed and have the potential to reduce adverse clinical events

Rationale for UseRationale for Use

Magnified photographs of the FilterWire device after the procedure (scale bar=1 cm) showing plaque debris collected in the filter basket

Reproduced with permission from Choudhury, R. P. et al. Circulation 2004;109:803-804.

According to mechanism of operation: Distal occlusion aspiration system: occlusion balloon passed distal

to lesion and inflated, before intervention, to occlude flow so as to create a column of stagnant blood which collects plaque debris that is subsequently removed with an aspiration catheter [Ex: PercuSurge GuardWire (Medtronic, Minneapolis, MN) and TriActiv system (Kensey Nash Corp., Exton, PA)]

Distal filter: uses a filter basket as opposed to a balloon, traps debris but maintains distal perfusion and ability for contrast imaging during the procedure (Ex: Spider, FilterWire, etc.)

Proximal occlusion aspiration system: inflow balloon occlusion proximal to the lesion (Ex: Proxis, Parodi, Gore flow reversal, Mo.Ma Ultra proximal cerebral protection device, etc.)

Types of EPDsTypes of EPDs

EPD Types: Strengths and LimitationsEPD Types: Strengths and LimitationsDistal

OcclusionDistal Filter Proximal Occlusion

Embolization on wiring / pre-dilatation/device crossing

+ + -

Failure to capture debris < 100μm

- + -

Failure to capture soluble mediators

- + -

Ischemia during balloon occlusion

+ - +

Limited contrast opacification

+ - +

Unlimited debris capture + - +

Shunting of debris into proximal side branches

+ - -

Major Trials of EPDs in SVG InterventionMajor Trials of EPDs in SVG Intervention

Trial Device No. of Patients

30-Day MACE, %

P-Value

Design

Distal occlusion deviceSAFER GuardWire vs. Conventional guidewire 801 9.6 vs. 16.5 0.004 Superiority

PRIDE TriActiv vs. GuardWire 631 11.2 vs. 10.1 0.02 Non-inferiority

Distal filter deviceFIRE FilterWire vs. GuardWire 651 9.9 vs. 11.6 0.0008 Non-inferiority

CAPTIVE CardioShield vs. GuardWire 652 11.4 vs. 9.1 NS Non-inferiority

TRAP TRAP vs. Conventional guidewire 358 12.7 vs. 17.3 0.24 Superiority

SPIDER SPIDER vs. FilterWire or GuardWire 732 9.1 vs. 8.4 0.012 Non-inferiority

AMEthyst Interceptor PLUS vs. FilterWire or GuardWire

797 8.0 vs. 7.3 0.025 Non-inferiority

Proximal occlusion devicePROXIMAL Proxis vs. FilterWire or

GuardWire594 9.2 vs. 10 0.006 Non-inferiority

Major Trials of EPDs in Native Coronary STEMIMajor Trials of EPDs in Native Coronary STEMITrial Device No. of

PatientsPrimary Endpoint Result, % P-

Value

Distal occlusion device

EMERALD GuardWire Plus vs. Conventional guidewire

501 ST-segment resolution at 30 mins

Infarct size

63.3 vs. 61.9

12.0 vs. 9.5

0.78

0.34

Tahk et al.* GuardWire Plus vs. Conventional guidewire

116 TIMI grade-3 flowTMP grade-3Hyperemic Average Peak Velocity

96 vs. 8165 vs. 38

39.2 ± 16.7 vs. 30.6 ± 10.8 cm/s

0.0160.0010.014

MICADO GuardWire Plus vs. Conventional guidewire

167 No-reflowTIMI grade-3 flowTMP grade-3

4 vs. 380 vs. 7658 vs. 44

0.730.1820.054

Ochala et al. GuardWire Plus vs. Abciximab

120 TIMI grade-3 flow 89 vs. 89 NS

ASPARAGUS GuardWire Plus vs. Conventional guidewire

329 TIMI grade-3 flow 77 vs. 78 0.73

Major Trials of EPDs in Native Coronary STEMIMajor Trials of EPDs in Native Coronary STEMITrial Device No. of

PatientsPrimary Endpoint Result, % P-

Value

Distal filter device

PROMISE FilterWire EX vs. Conventional guidewire

200 Maximum adenosine-induced flow velocity

34±17 vs. 36±20 cm/s

0.46

UpFlow MI FilterWire EZ vs. Conventional guidewire

100 TIMI grade-3 flowBlush score-3ST-segment resolution at 60 mins

88.2 vs. 93.968.1 vs. 669.4 vs. 10.7

NSNSNS

DEDICATION FilterWire vs. Conventional PCI

626 ST-segment resolution at 90 mins

72 vs. 76 0.29

PREMIAR SpiderRX vs. Conventional PCI

140 ST-segment resolution at 60 mins

60 vs. 60 0.99

Proximal occlusion devices

PREPARE Proxis vs. Conventional PCI 284 Complete ST-segment resolution at 60 mins

80 vs. 72 0.14

Class I Distal embolic protection devices be used with PCI to saphenous

vein grafts when technically feasible

IndicationsIndications

Smith SC Jr, et al. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention. Available at: http://www.acc.org/clinical/guidelines/percutaneous/update/index.pdf.

Carotid artery stenting

Data to date do not support the routine use of EPDs for native coronary artery PCI (either stable CAD or acute MI setting)

Other vascular beds - EPDs have been studied for renal artery stenting and other peripheral stenting. There are no robust data to attest to their efficacy at present

Other IndicationsOther Indications

Avoid distal EPDs in vessels with excessive tortuosity

Do not deploy EPDs in the region of stent

Do not over- or under-size the EPD

Contraindications / CautionContraindications / Caution

EquipmentEquipment

Distal filter device (FilterWire EZ)FilterWire device is composed of a protection wire and a delivery and a

retraction catheter

Protection wire - composed of a nitinol mesh filter with a distal radiopaque spring tip, mounted on a 190 cm or a convertible 300/190 cm cm PTFE-coated 0.014 inch stainless steel wire

Reproduced with permission from Boston Scientific Corporation

EquipmentEquipment

Distal filter device (SpiderFX® Embolic Protection Device )SpiderFX device is composed of a Capture wire and a SpiderFX Catheter

Capture wire - composed of a nitinol mesh filter with a distal floppy tip, mounted on a 190 cm or a convertible 320/190 cm PTFE-coated 0.014 in stainless steel wire pre-loaded through the delivery end of the SpiderFX catheter

Reproduced with permission from eV3 Inc.

EquipmentEquipment SpiderFX Catheter - dual-ended catheter, with a delivery end (green)

and a recovery end (blue) at the opposite end of the catheter

Reproduced with permission from eV3 Inc.

TechniqueTechnique

Antiplatelet: Aspirin and thienopyridine as per institutional practice

Anticoagulation: bivalirudin or heparin (with or without GP2b3a) as per routine clinical practice

6F guide catheter to engage the coronary ostium

Standard 0.014 inch guidewire to cross the lesion (with the Spider)

Identify the location where the filter will be deployed, preferably 2.5 to 3 cm distal to the lesion site

Measure the vessel diameter in this location and choose the appropriate filter diameter size

Do not undersize (inadequate vessel wall apposition resulting in embolization of debris) or oversize (vessel wall damage and or slow/no-flow)

TechniqueTechnique

Preparing the device Under sterile conditions, remove the EPD device components with the

hoop from the packaging Hold the catheter at the distal tip and submerge only the filter in

heparinized saline to wet and remove air. Pull the capture wire proximally until the filter portion stops in the clear segment of the catheter

Flush through the distal tip with heparinized saline until all air is removed and saline passes from the primary wire exit port

Gently apply pressure to the primary wire exit port and continue flushing until all air is removed and saline passes from the capture wire exit port

TechniqueTechniqueDeploying the device After crossing the lesion with a standard 0.014 in guidewire, load the distal

tip of the EPD catheter (green) on to the proximal part of the guidewire Gently bend the catheter at the primary wire exit port to allow the primary

guide wire to exit easily Advance the catheter over the primary guidewire, past the lesion until the

radiopaque marker at the distal tip of the delivery end is at least 4-5 cm beyond the distal edge of the lesion

Fix the catheter in this position and now withdraw the primary guidewire, leaving the delivery catheter with the capture wire in place

With the catheter fixed with one hand, gently advance the capture wire until the distal radiopaque marker band on the filter aligns with the radiopaque marker on the catheter distal tip

Under fluoroscopy ensure that the proximal radiopaque marker band is at least 2 cm distal to the lesion treated. If not, advance the unit as a whole until the desired position is reached

Fix the capture wire with one hand and gently pull back the catheter to expose and deploy the filter. Remove the catheter from the patient

TechniqueTechniqueRecovery and removal of the device After completion of PCI using the capture wire as the primary guidewire, use

the recovery end of the catheter to remove the filter Flush the distal tip of the recovery end (blue) to remove all air, until saline

passes from the capture wire exit port Load the recovery end of the catheter and advance until the distal tip

radiopaque marker aligns with the proximal radiopaque marker band on the filter

Gently advance the recovery end over the filter until the proximal portion of the filter is inside the catheter (partial enclosure recovery) or until all radiopaque markers on the filter are within the catheter (full enclosure recovery)

Carefully remove the catheter and the capture wire together as a unit Open the hemostasis valve on the guide catheter to allow the EPD catheter to

exit and also to flush any thrombus which may have escaped into the guide catheter

TechniqueTechniqueFilterWire The deployment of FilterWire is similar, except the protection wire serves as

the guidewire and a conventional guidewire is not used prior to deployment of the FilterWire

Submerge the filter and distal tip of the delivery sheath in heparinized saline and capture the filter by pulling it into the sheath

Place the peel-away introducer sheath over the spring tip and insert into the hemostasis valve of the guiding catheter and advance

Peel the sheath introducer off and advance both the wire and delivery sheath together to the end of the guide catheter

Now attach a torquer to the protection wire and steer the wire using the torquer with one hand while advancing the sheath with the second

Advance the filter and deploy minimum 3.0 cm distal to the lesion. Advance the torquer to the hemostasis valve and tighten

Holding this in place, pull back and remove the delivery sheath by peeling it away. The filter is now ready for use

Retrieval is similar to the description above

Short flexible catheter attached to a hypertube catheter shaft (7F)

Short distal circumferential balloon at the tip

Proximal balloon within guide

Proximal end of the catheter has a built in standard Y-adaptor with a hemostasis valve for guidewire and device entry, a luer connection for aspiration and an additional luer connection for the sealing balloon inflation device

Deployed in proximal vessel (needs at least 10mm landing zone)

Balloon inflated at 2/3 atm, causing stasis of flow

Proximal EPD - Proxis Device*Proximal EPD - Proxis Device*

Proxis(tm) is a trademark of St. Jude Medical.  Reprinted withpermission from St. Jude Medical, (c) 2010 all rights reserved

Distal balloon

*currently not in production in the US

Proximal vs. Distal ProtectionProximal vs. Distal Protection

Ideal case for proximal protection Distal lesion with <4-5 cm

length of vessel beyond the lesion

Minimal proximal atherosclerosis

Ideal case for distal protection Lesion with at least 4-5 cm

length of vessel beyond the lesion as a landing zone

Minimal landing zone atherosclerosis

Distal protection - GuardWireDistal protection - GuardWire

Reproduced with permission from Baim, D. S. et al. Circulation 2002;105:1285-1290.