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
A lesion with TIMI 0 flow within the occluded segment
that is judged to be at least 3 months in duration
Heart 2012;98:822-828
Eurointerven 2007 :30:43
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
Improved tolerance of a future ACS
JACC 2006;47:721–5
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
Indication
Aim – To improve symptoms and/or prognosis
Currently reopening of a CTO
Presence of symptoms
OR
IMPROVED
GLOBAL
Objective evidence ofREGIONAL
viability/ischaemia in&
territory
of
LV
FUNCTION
ESV
occluded
artery of more than10% is fully
sanctioned by theEF
current guidelines on myocardial revascularisation
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
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
Guide catheter selection
First key to success
For effective guide wire manipulation :
coaxial orientation
of guide catheter important
stability& back up force
RCA
Shepared crook RCA Prox RCA lesion
LCA
LCX (short leftmain)
-
AL1/0.75 with sideholes
AL1or2
JR ( avoid ostial damage)
Extraback up (XB,EBU,BL)
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
Four wire strategy
Hydrophillic &/or polymerjacket
0.014 inch,low gram force with
tapered tip
Antegrade microchannel/
soft tissue probing
knuckle technique
Eg : Fielder XT wire (Asahi Intecc) tip-0.009
Runthrough taper wire (Terumo – 0.008
Nontapered ,polymer jacket
Hydrophillic,0.014 inch GW
collatrel channel crossing
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)
Polymer jacket,nontapered
0.014 inch GW
complex lesion crossing
long lesion,knuckle technique
Dissection /rentry
tortuous lesion with ambigous
course
Eg: Pilot-200 GW(Abbott Vascular)
High gram force ,0.014GW
tapered,0.009
Nonjacketed tip
Penetration techniques
Cap puncture
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
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
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
Soft tapered polymer
jacket wire
DUAL 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
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
2ºbend-10-15º
@3-6mm
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
Different methods
Sliding
Drilling
Penetration
AT
proximal cap
inside CTO
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
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
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
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
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
CART
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
THANK YOU
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
Also available
150-2.7g
200- 4.1g
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
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
Female asian patients
Prox LAD
LAD & circumflex-
-
Brite tip-(deeper 2º curve)
Launcher SAL-1
Judkins short tip
EBU or Voda
guideliner