Chronic Total OcclusionPCI – Strategies

Dr Arun

CTO-DEFINITION

100% luminal diameter obstruction without flow in that segment of 3 or more months duration

Presence of TIMI 0 flow within an occluded segment with an estimated occlusion duration of >/= to 3months

Eurointerven 2007 :30:43Heart 2012;98:822-828

A lesion with TIMI 0 flow within the occluded segment

that is judged to be at least 3 months in duration

WHY TO OPEN UP A CTO ?

Significant clinical problem (JACC intvn 2009;2:489 –97)

Similar risk to non CTO PCI (JACC intvn 2009;2:489 –97)

Angina relief (FACTOR TRIAL-2010)

Improved L V function JACC 2006;47:721–5

Improved tolerance of a future ACS JACC intvn 2009;2:1128 –34

Potentially better survival with successful PCI AmHeart J 2010;160:179-87

Avoidance of CABG AmHeart J 2010;160:179-87

IMPROVED REGIONAL & GLOBAL LV FUNCTION - ESV EF

Limited or no late enhancement on Gd MRI is an excellent

predictor of late left ventricular recovery after CTO

recanalisation

Indication

Aim – To improve symptoms and/or prognosis

Currently reopening of a CTO Presence of symptoms OR

Objective evidence of viability/ischaemia in territory of

occluded artery of more than 10% is fully sanctioned by the

current guidelines on myocardial revascularisation

EuroIntervention 2012;8:139-145

Histopathological insights

Healing total occlussionFibrin-red, proteoglycan-bluishgreen Vascular channels- asterisks

Asterisks- vascular channelsYellow- collagen rich matrix

EuroInterv.2006;2:382-388

Histopathological progression – not clearly understood

Belief –once occlusion occurs thrombus formation upto sidebranch

Important components of occlusion Proximal cap, Calcification microvessels ,loose tissue, distal cap

EuroInterv.2006;2:382-388

Microchannels Often extend to smallside branch & to adventitia

Extravascular microchannels in early phase of occlusion More mature CTO –intravascular channels increase Matured CTO - both fewer Longitudnal continuity – 85% of entire lenghth of CTO

J Am Coll Cardiol Intv 2011;4:941–51

Continuous loose tissue segments frequently in tapered entry CTO

Majority of CTO autopsy specimen were not totally occluded

Non occluded lesions were not related to the age

Histopathological subintimal space after failed procedure

Sumitsuji et alJACC intvn sep 2 0 1 1 : 9 4 1 – 5 1

Preprocedure planningParamount importance – planning mistakes difficult to circumvent half way through the procedure

Spend time examining diagnostic films & decide on

Approach ,vascular access, guide shape & size dedicated equipment availability

Discourage routine adhoc CTO PCI

Occluded & contralateral vessel reviewed in multiple projection frame by frame to understand complete anatomy identify proximal & distal cap vessel course & sidebranch calcification details of collateral circulation

Contrast volume defined prior to procedure - 4xGFR(ml)

EURO CTO club;2012 consensus

Role of dual injection

Critical for performing CTO PCI–in all case of contralateral collateral

Allows for optimal visualization of CTO vessel

Crucial for determining lesion length, size & location of distal target vessel

To asses any bifurcation at distal cap

Assess presence, size & tortuosity of collateral vessel

Best performed At low magnification ,prolonged imaging exposure No table panning - allows for optimal delineation of CTO segment collateral vessel location & course

JACC intrvn2012;5:367-79

First inject donor – then occluded vessel – minimize radiation

Septal collaterals best visualized –RAO cranial OR straight RAO

Epicardial collaterals need tailored view

more often from diagonal ,LCX or PLV

LAO & RAO cranial – Best to image distal lateral wall collaterals(OM-PLV, diagonal to diagonal/OM connections)

RAO & AP caudal- proximal OM collaterals and those in AV groove

JACC intrvn2012;5:367-79

Repeat procedures – when to stop Repeat procedures – More common with CTO

failure of a specific recanalization strategy staging of otherwise progressing procedure

Parameters to consider before repeat procedure

First attempt complete ?

contemporary technique & materials properly employed

reason for failure recognized ? clear alternative strategy for reattempt ?

General rule- two attempts at a CTO

Know when to stop key issue in CTO PCI dissection of distal lumen – Better to abandon procedure

Access route

Depend on individual patient situations

Operator preference & experience

Femoral artery - usual and preferred access in most labs(90% - Europe)

Trans radial PCI for CTO - increased

AnticoagulationUFH – ease of use & available antidote

Avoid bivaluridin &gp 2b 3a inhibitor

Brilakis et al,2012Korean Circ J 2010;40:209-215

Bifemoral approach - characteristic of CTO PCI

Side hole guide catheters >/= 7F - both antegrade & retrograde Long femoral sheaths (>/=30cms) - further support (tortuous arteries)

Back up support & sidehole - essential in guide selection

IVUS guided PCI - 8 F guide catheter to accommodate 2 catheters (IVUS catheter and microcatheter)

Simultaneous double contrast injection is mandatory

Yamane M. Rev Esp Cardiol. 2012.

Successful CTO PCI require attention to subtle techniques

Guide wire crossing of CTO –most difficult & important

Guidewire selection & manipulation tactics – key issues

Successful guidewire manipulation requires adequate preparation, guide selection & angiographic techniques

DEVICES

Guide catheter selection

For effective guide wire manipulation : coaxial orientation of guide catheter important stability& back up force

Guide catheter stability insufficient or unable to achieve

May use Anchor technique for guide catheter stabilization

First key to success

RCA - AL1/0.75 with sideholesShepared crook RCA - AL1or2Prox RCA lesion - JR ( avoid ostial damage)LCA - Extraback up (XB,EBU,BL)LCX (short leftmain) - AL1 or2 (better support & co-axial)

Korean Circ J 2010;40:209-215

AL from different companies

Anchoring techniquefor guide stabilization

EuroInterv.2006;2:375-381

OTW baloon inserted in a small sidebranch inflated at low pressure (2mm @ 8atm here)

Guide wiresCrossing the lesion with GW – very important step in CTO PCI

Floppy wire- initial choice

Exchange to a stiffer dedicated guide wire

Polymer coated wires – poor tactile feedback, lack of resistance more chance of subintimal passage

Majority favour – step up approach – moderately increased stiffness(miracle-3) – switch to greater stiffness &penetration ability, taperd (conquest pro wires)

Some believe –use of stiffer wires initially to cross hard occlusion cap Rationale: risk of initial dissection minimized, procedure shortened & simplified with this approach

Kcj 2010

Most common reason for failed CTO PCI- failure of GW to cross

Four wire strategy

Hydrophillic &/or polymerjacket Antegrade microchannel/ 0.014 inch,low gram force with soft tissue probingtapered tip knuckle technique

Eg : Fielder XT wire (Asahi Intecc) tip-0.009 Runthrough taper wire (Terumo – 0.008

Nontapered ,polymer jacket collatrel channel crossingHydrophillic,0.014 inch GW in retrograde procedures

Eg: Fielder FC wire(Asahi Intecc) Pilot 50 wire (Abbott Vascular)

JACC intrvn2012;5:367-79

Moderately high gram force(4-6) complex lesion crossingPolymer jacket,nontapered long lesion,knuckle technique0.014 inch GW Dissection /rentry tortuous lesion with ambigous course

Eg: Pilot-200 GW(Abbott Vascular) High gram force ,0.014GW Penetration techniquestapered,0.009 Cap punctureNonjacketed tip Complex lesion crossing Lumen reentry techniques Eg: Confianza Pro 12 wire (Asahi Intecc)

JACC intrvn2012;5:367-79

Guidewires for micro channel tracking

CTO LIVE 2007

JACC intrvn2012;5:367-79

JACC intrvn2012;5:367-79

Guide wire strategies for approaching total occlusions

Indian heart journal:2009;61:178-85

Guide wire selection & Microcatheter based on PCI strategy

KEY ELEMENTS TO RECOGNIZE a) Tapered (0.009 in) or not b) Polymer jacket or not c) Stiffness d) Trackability

IVUS guided reentry from subintimal space to true lumen

Tapered High gram stiff wire

Soft polymer jacket wire + microcatheter has improved chance of antegrade recanalization in first attempt

Initial microchannel tracking - soft tapered polymer jacket wire

Microcatheters

Low profile,trackable OTW microcath - indispensable tool for CTO PCIAllow ease of wire exchange ,floppy for dedicated stiffer wire

Facilitates transmission of torque to tip & improve feedback

Allows primary & secondary curve adjustment

Modulates tip stiffness of guide wire

Dedicated microcatheters – better tip flexibility > OTW balloonsUseful for CTO immediately distal to a bend

Larger inner lumen – reduces friction during wire manipulation

Disadvantage : rarely able to cross occlusion to be exchanged with OTW baloons

Tips for use

For wire exchange – inject saline to lumen- avoids introducing airTrapping technique

Finecross microcath

terumois.com

Tornus

Rotate anticlockwise to advance

Clockwise to remove

Screw pitch

Tornus -1.1mm

Tornus 88Flex - 1.7mm

Require exchange length wire for removal

Corsair Tapered soft tipNegotiate tortuous channelsPlatinum markerDistal 60 cm- hydrophilic coating

Tungsten braiding +10 elliptical stainless steel braidsSHINKA-Shaft

Excellent pushability and flexibility due to unique construction

Enables contrast injection and wire exchange

Superb manoeuvrability due to excellent hydrophilic coating

Kink resistant soft radiopaque tapered tip

135cm (antegrade) or 150cm (retrograde) lengths available 

Corsair Features

OTW Balloons

STRATEGIES FOR PCI OF CTO

DUAL WIRE SINGLE WIRE

Soft tapered polymer jacket wire

Middle weight spring coil wire

High gram tapered wire

Parallel wire technique

Bilateral retrograde approach

IVUS guided approach

Yamane M Rev Esp Cardiol. 2012.

Attempted in this order chance of successful recanalization - 90%

Clinical background & situation dictates - onetime or a staged procedure

2nd or 3rd attempt in case if unsuccessful procedure

Yamane M Rev Esp Cardiol. 2012

Antegrade approach

Guide wire Tip shaping

Wire tip shaped as short as possible <45º

Second milder curve - improve maneuverability of wire

Exception - a sharp (>60º) angle with 1 to 2 mm bend based on lumen size, to navigate the wire from subintimal space back to true lumen( Parallel wire technique or IVUS guided wiring)

Confianza Pro or Pilot 200 - best suited to this purpose

EuroInterv.2006;2:375-381

How short tip can be bent – depends on length of soldering of spring coil at tip

Usually -1mm, fielder XT -<1mm

Korean Circ J 2010;40:209-215

Shaping the wire

1ºbend of 30-45º1-2mm from tipFind softest part

2ºbend-10-15º@3-6mmWork as a navigator to orient tip

Tip curve should be just larger than lumen diameter

CTO, the lumen diameter = 0 mm

For CTO lesion - Guidewire-tip curve should be very small

Larger curve may hurt the vessel wall during direction control

Hermiller ,SCAI Fellows Course 2009

Guide wire handling

Different methods Sliding AT proximal cap Drilling inside CTO Penetration Distal cap

Short, focal, straight noncalcified lesion – any method

Long tortuous calcified occlusion – wiring tailored to lesion characteristics

Hard fibrocalcific plaque and tortuosity in CTO- major obstacle

Combination of penetration and sliding over a microcatheter

watching the wire tip in relation to lumen in at least 2

orthogonal views

Yamane M Rev Esp Cardiol. 2012

Simultaneous rotation & probing of lesion High chance of entering to subintimal space ( tactile response - nil )

SLIDING

Relatively recent occlusion with predominance of microchannels

Extremly low friction wires for picking microchannels used

Recent total, subtotal occlusion ,ISR attempted with this strategy

Long duration – Microchannels replaced by fibrotic tissue

Indian Heart J. 2009; 61:275-280

BEWARE bridging collaterals masquerading as microchannel

Polymer sleeved wires NOT forced against resistance, small tip bend, probing with mild rotation

Soft wires with polymer sleeve – Fielder series/ Whisper/ PT II

Drilling Strategy

If discrete entry point present

Technique short curve(2mm) @45-60º to distal tip

sometimes a secondary curve given proximally

wire advanced with rapid rotational tip and gentle probing

start with MOD stiffness – progressive increase in stifness

Entry to false lumen judged by tactile feel on pulling stiff wire

Reserved for the most skilled and experienced operator

Ineffective with Blunt entry ,heavily calcific & resistant lesions

Indian Heart J. 2009; 61:275-280

Penetration

TechniquePushing stiff wire slowly& gradually – minimum rotation to target direction

Tapered tip wires Softer tip intially progressively stiffer wires Route determined – various angio or CT findings not by tactile feel

Useful for blunt ,heavily calcific or resistant lesions

Not for CTO with tortuous angulated or bridging collaterals because of higher chance of perforation

Drilling & penetration – guide support & tipload important

Tip load - success - chance of perforation

Penetration power = tipload/tiparea

May use to redirect in conjunction with parallel wire technique

Parallel wire technique or Seesaw wiring

1st wire in false channel

left in situ

2nd stiffer wire advanced parallel to first wire in same path

redirected to enter distal true lumen

main pitfall is wire twisting each other

Support catheter use, appropriate wire selection& handling –essential to avoid wire twisting

Main purpose : - redirecting a wire inside body of a cto & puncturing distal fibrous cap

Important prerequisite – distal vessel visualization

Korean Circ J 2010;40:209-215

Visualization of 1st GW & its relative position to 2nd GW using orthogonal view is essential for success of technique

Adopt the technique before a large subintimal dissection

Chance of successful recanalization by 2nd wire decreases proportionally to the extent of subintimal dissection inducedby the first guidewire

2nd wire –stiffer with superior torquabilityEg:Miracle12 or Conquest Pro

Check in multiple angiographic views

Advantagesa)Decreased fluro timeb) Reduced contrast

See-saw wiring technique

Modification of parallel wire technique

Uses 2 microcatheters or OTW baloons

When first wire fails , 2nd wire with microcatheter or OTW baloon is inserted

Risk – false lumen may enlarge – procedure failure

Japanese operators demonstrated ability to improve wire crossing over time with this technique(Nakamura& Bae 2008)

IVUS Navigated Wiring

IVUS – Depict cross sectional view of coronary tree

IVUS focus on plaque distribution, calcification, reference vessel size & side branch anatomy

Applicability of IVUS in CTO PCI

1)Side branch method to navigate CTO wire into true lumen from proximal cap 2)Subintimal rentry from the proximal true lumen

IVUS guided subintimal rentry – Last resort for getting a subintimal wire into distal true lumen

Applicable even after losing site of distal vascular bed on angio

1.5-2mm baloon dilatation in presumed subintimal space

IVUS is advanced into the space monitored to orient 2nd wire to true lumen

Key points a) Ability to translate crosssectional image into 3D needed

b) 2nd stiff tapered wire over microcatheter - 8f guide mandatory

c) Rentry point should be closer to proximal cap

d) Contrast injection should be withheld esp after small ballon dilatation

Importance of wire crossing from true lumen to true lumen

If Subintimal wire crosses without many side branch compromise

Subintimal stenting practical

CTO PCI should be planned to minimize subintimal wiring

Subintimal wiring & stenting – unavoidable in some

Eg: severe fibrocalcific occlusion over a negatively remodelled segment

Larger distal vascular bed – higher chance of TIMI-3 flow

STAR Technique - Subintimal tracking and rentry technique

Used when attempts to recanalize true lumen failed

0.014 hydrophillic wire with J configration used(whisper,pilot)

Hydrophillic wire pushed through subintimal dissection plane

When pushed distal to occlusion J tip directed to truelumen

In an attempt to reenter

Successful in those with previous attempt failed

High chance of perforation

Catheter Cardiovasc Interv 2005;64:407–411

Dissection reentry techniques

Knuckle wire technique

Similar to wire loop technique used in long SFA occlusion

Polymer jacket wire (fielder XT or pilot-200)manipulated

to create wire loop – advanced subintimally-across CTO –

OTW system advanced to this area- rentry to true lumen with a stiffer wire or pilot 200

Cross Boss catheter

Metal OTW microcatheter with rounded tip to prevent vessel exit

Device rotated rapidly in either direction using fast spin

Can advance through the CTO without a wire in the lead

Subintimal position- true lumen reentry performed

Smaller subadventitial space – less likely to accumulate blood

bostonscientific.com

Sting ray balloon & guidewire system

1mm flat balloon with 3 exit ports connected to the same lumen

Distal exit port – for balloon positioning

Other 2 180º opposed to each other

Uses guidewire with extreme tapered tip (0.0025) for rentry

Distal true lumen entry confirmed by contralateral injection

bostonscientific.com

RETROGRADE APPROACH

Initially used after a failed antegrade approach

Now used as initial strategy in challenging cases 1) Ostial occlusion 4) Large side branch at proximal cap 2) Long occlusion (>30mm) 5) Severe tortuosity or calcification 3) Without stump 6) Visible continuous collatrels Dual femoral arterial access preffered

Long sheaths for additional passive support

Anticoagulation – heparin ,ACT at least every 30min - >350 sec

Use of short guide allow long reach

Collateral selection

Preference - Bypass graft > septal > epicardial

Selective injection of collateral

Surfing technique for crossing invisible septal collateral

Wiring collateral – achieved with OTW system or dedicated septal dialator(corsair)

Entering septal collaterals large bend or 2 small bend in a work horse wireContrast injection to assess best connection

Before injection – aspirate to remove air in microcatheter

Dripping saline over hub during insertion& removal of guidewire

Hydrophillic polymer jacket wire with <1mm 30-45º tip used to cross recipient artey

Fielder FC,Pilot-50,Whisper, Choicept,Runthrough

Wiring done in diastole

Wire should move freely - difficulty to advance – perforation?

PVC or whipping of wire - RV or LV entry (rarely pericardium)

Of no consequence if recognized before advancing OTW system

Collateral dilatation using 1.5 mm balloon @ 1-2 atm or Corsair

Epicardial collaterals size most important factor in wiring success should never be dialated

Antegrade crossing

Simplest form of retrograde technique

Retrograde wire advanced to distal cap

Acts as a marker of distal true lumen

Serves as a target for antegrade wire

Saito, Catheterization and Cardiovascular Interventions 71:8–19 ,2008

Kissing wire

Manipulation of both antegrade and retrograde wires in CTO until they meet

Antegrade wire follow channel made by retrograde wire in true lumen of distal vessel

Retrograde true lumen puncture

Most pure form of retrograde technique(only in 40% retro tech)Hydrophillic wire advanced to the lesion

Advancment of microcatheter or OTW baloon – additional support

CTO crossed retrogradely using hydrophillic wire or stiffer wire

Manuevers to enhace chance of crossing

Inflating retrograde baloon - coaxial anchor

Stiffer tapered tip or hydrophillic wires

IVUS facilitation of retrograde wire to proximal true lumen

Controlled antegrade & retrograde subintimal tracking

C A R T

Basic concept –create subintimal dissection with limited extension only at the site of a CTO

Antegrade wire advanced into CTO then to subintimal space.

Retrograde wire through collatrel with microcatheter to distal end of CTO - into the CTO- then to subintimal space

Baloon inflation inside CTO using small balloon over the retrograde wire to subintima

Balloon inflated inside CTO

To keep inflated space open deflated baloon left in subintimal space

Surmely Jf et alnJ Invasive Cardiol 2006;18:334–338

Two subintimal dissection provide reentry space for antegrade wiring

Antegrade wire advanced along deflated retrograde balloon into the distal true lumen

Limited subintimal tracking (dissection) only in CTO segment

Avoids difficulty of reentering distal true lumen

Dilatation and stent implantation after successful recanalization

CART - steps

Use closest sized baloon inside CTO to create sufficient wire reentry space

Access to distal CTO mainly via septal collatrels, by polymer jacket wire over microcatheter or otw baloon

Septal channel dilatation at 1.25mm baloon at low pressure

Major limitationsLimited access of collatrel channels to target CTO

Empiric estimation of retrograde baloon size

Overall unpredictable procedure time

Reverse CART technique

Engage a guidewire retrogradely in the distal cap of the CTO

Another wire anterogradely in the proximal cap of the CTO Retrograde wire advanced in subintimal space into CTO lesion

Subintimal channel is enlarged by anterograde balloon

Plaque dissection and modification of the lesion

Retrograde wire advanced to cross the dissection

Link up with the anterograde wire in proximal true lumen

Wire externalized (Exchange length)

Anterograde PCI done

KNUCKLE WIRE TECHNIQUE

Best suited for long segment of occlusion

Retrograde wire usually a polymer jacket wire manipulated to form a loop at wire tip advanced in subintimal space across CTO

Eg: Fielder XT or Pilot-200

Rounded wire loop advanced in subintimal space across CTO without causing perforation

OTW system advanced to this area followed by attempt to reenter

true lumen using a stiffwire with short bend or hydrophillic wire Eg: Confianza Pro 12 or Pilot 200

Treating lesion after crossing

CTO crossed by antegrade wiring (kissing wire, just marker,CART

Antegrade CTO PCI can be done

Retrograde balloon can trap antegrade wire to facilitate procedure

Retrograde wire crosses to true lumen

Options : Antegrade wiring Retrograde wire externalization Retrograde stent delivery

DES is preferred in CTO PCI

Antegrade wiring

Retrograde baloon angioplasty

Antegrade wire crosssing - stenting Double anchoring technique for supportFacilitated by

Antegrade micro catheter probing technique

Bridge or Rendezvous method

Reverse wire trapping

Viper advance wire preffered for retrograde wire externalisation

Retrograde stent delivery – risk of stent entrapment & dislodgment

Complications

Thrombosis and dissection of donor artery

Collateral perforation & occlusion treated with coil embolization injection of autologus subcutaneous fat tissue/thrombus emergency CABG

Entrapment of pci equipment in septal collaterals

Radiation skin injury/CIN/

Subintimal stenting – late coronary aneurysm & stent fractures

THANK YOU

GUIDEWIRES

Penetration force

Runthrough N S

Fielder-XT

Cross-it 100XT

Tip load-1.7gm Tapered tip coil design (0.014” to 0.010” at distal 3 cm) Hydrophilic coating over distal 30 cm PTFE coating over proximal portion Stainless steel core

Abbot vascular

0.010

Abbot vascular

HI-TORQUE PILOT 50 Guide WireTip load: 1.5gRadiopaque length: 3 cmOutside diameter: 0.014"Tip Outside diameter: 0.014" Coating: HydrophilicTip style: Core to tipPolymer cover: Full Polymer CoverCore Material: DURASTEEL Stainless Steel

Also available150-2.7g200- 4.1g

       HI-TORQUE WHISPER LS Guide Wires

Tip load: 0.8gRadiopaque length: 3 cmOutside diameter: 0.014"Tip Outside diameter: 0.014"Coating: HydrophilicTip style: Core to tipPolymer cover: Full Polymer CoverCore Material: DURASTEEL Stainless Steel                                                         

RCA with down ward take off- JR or AL Male asian patients - Brite tip-(deeper 2º curve)Female asian patients - Launcher SAL-1 Prox LAD Judkins short tip LAD & circumflex- EBU or Voda

guideliner