Chronic Total Occlusion PCI – Strategies Dr Arun

CTO-DEFINITION Eurointerven 2007 :30:43 100% 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 A lesion with TIMI 0 flow within the occluded segment that is judged to be at least 3 months in duration Eurointerven 2007 :30:43 Heart 2012;98:822-828

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 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 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 EuroIntervention 2012;8:139-145

Histopathological insights Healing total occlussion Fibrin-red, proteoglycan-bluishgreen Vascular channels- asterisks Asterisks- vascular channels Yellow- 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 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 EuroInterv.2006;2:382-388 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 al JACC intvn sep 2 0 1 1 : 9 4 1 – 5 1

Preprocedure planning Paramount importance – planning mistakes difficult to circumvent half way through the procedure Discourage routine adhoc CTO PCI Spend time examining diagnostic films & decide on Approach ,vascular access, guide shape & size dedicated equipment availability 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 UFH – ease of use & available antidote Anticoagulation UFH – ease of use & available antidote Avoid bivaluridin &gp 2b 3a inhibitor 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 Korean Circ J 2010;40:209-215 Brilakis et al,2012

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 First key to success For effective guide wire manipulation : coaxial orientation of guide catheter important stability& back up force RCA - AL1/0.75 with sideholes Shepared crook RCA - AL1or2 Prox RCA lesion - JR ( avoid ostial damage) LCA - Extraback up (XB,EBU,BL) LCX (short leftmain) - AL1 or2 (better support & co-axial) Guide catheter stability insufficient or unable to achieve May use Anchor technique for guide catheter stabilization Korean Circ J 2010;40:209-215

AL from different companies Anchoring technique for guide stabilization OTW baloon inserted in a small sidebranch inflated at low pressure (2mm @ 8atm here) EuroInterv.2006;2:375-381

Guide wires Crossing the lesion with GW – very important step in CTO PCI Most common reason for failed CTO PCI- failure of GW to cross 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

Four wire strategy Hydrophillic &/or polymerjacket Antegrade microchannel/ 0.014 inch,low gram force with soft tissue probing tapered tip knuckle technique Eg : Fielder XT wire (Asahi Intecc) tip-0.009 Runthrough taper wire (Terumo – 0.008 Nontapered ,polymer jacket collatrel channel crossing Hydrophillic,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 crossing Polymer jacket,nontapered long lesion,knuckle technique 0.014 inch GW Dissection /rentry tortuous lesion with ambigous course Eg: Pilot-200 GW(Abbott Vascular) High gram force ,0.014GW Penetration techniques tapered,0.009 Cap puncture Nonjacketed 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 Initial microchannel tracking - soft tapered polymer jacket wire 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

Microcatheters Low profile,trackable OTW microcath - indispensable tool for CTO PCI Allow 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 balloons Useful 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 air Trapping technique

Finecross microcath terumois.com

Rotate anticlockwise to advance Clockwise to remove Screw pitch 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 tip Negotiate tortuous channels Platinum marker Distal 60 cm- hydrophilic coating Corsair Features Tungsten braiding +10 elliptical stainless steel braids SHINKA-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  

OTW Balloons

STRATEGIES FOR PCI OF CTO SINGLE WIRE DUAL WIRE Soft tapered polymer jacket wire Parallel wire technique Middle weight spring coil wire Bilateral retrograde approach High gram tapered wire 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 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 EuroInterv.2006;2:375-381

Shaping the wire 1ºbend of 30-45º 1-2mm from tip Find softest part Work 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

SLIDING Relatively recent occlusion with predominance of microchannels Extremly low friction wires for picking microchannels used Simultaneous rotation & probing of lesion High chance of entering to subintimal space ( tactile response - nil ) 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 Technique Useful for blunt ,heavily calcific or resistant lesions Technique Pushing 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 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 Important prerequisite – distal vessel visualization Main purpose : - redirecting a wire inside body of a cto & puncturing distal fibrous cap main pitfall is wire twisting each other Support catheter use, appropriate wire selection& handling –essential to avoid wire twisting 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 induced by the first guidewire 2nd wire –stiffer with superior torquability Eg:Miracle12 or Conquest Pro

Check in multiple angiographic views Advantages a)Decreased fluro time b) 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 Ability to translate crosssectional image into 3D needed 2nd stiff tapered wire over microcatheter - 8f guide mandatory Rentry point should be closer to proximal cap 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 Larger distal vascular bed – higher chance of TIMI-3 flow CTO PCI should be planned to minimize subintimal wiring Subintimal wiring & stenting – unavoidable in some Eg: severe fibrocalcific occlusion over a negatively remodelled segment

Dissection reentry techniques 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

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 wire Contrast 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

C A R T Controlled antegrade & retrograde subintimal tracking 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 Dilatation and stent implantation after successful recanalization Limited subintimal tracking (dissection) only in CTO segment Avoids difficulty of reentering distal true lumen

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 limitations Limited 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 support Facilitated 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

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GUIDEWIRES

Penetration force

Runthrough N S

Fielder-XT

Cross-it 100XT 0.010 Abbot vascular 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 HI-TORQUE PILOT 50 Guide Wire Tip load: 1.5g Radiopaque length: 3 cm Outside diameter: 0.014" Tip Outside diameter: 0.014"  Coating: Hydrophilic Tip style: Core to tip Polymer cover: Full Polymer Cover Core Material: DURASTEEL Stainless Steel Also available 150-2.7g 200- 4.1g

HI-TORQUE WHISPER LS Guide Wires Tip load: 0.8g Radiopaque length: 3 cm Outside diameter: 0.014" Tip Outside diameter: 0.014" Coating: Hydrophilic Tip style: Core to tip Polymer cover: Full Polymer Cover Core 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