The document discusses strategies for percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs). It describes: 1. The antegrade approach is the most commonly used, with success rates of 60-80%. Tapered guidewires are first-choice to probe microchannels. 2. A four-wire strategy is recommended, starting with a polymer-coated wire and progressing to stiffer wires if needed. 3. Advanced techniques like parallel wiring or antegrade dissection and reentry may be used if initial wiring fails.

2. Introduction
 CTO are present in about 20% of patients with relevant CAD,
 History of remote myocardial infarction (MI) could be found in 42−68% of CTOs.
 Many patients with single or multivessel disease is referred for CABG because
extremely difficult and time-consuming task of addressing CTO by PCI.
 Thanks to specific wires and sophisticated techniques continuously evolving
since the early 1990s but, even more importantly, owing to a few strenuously
enthusiastic CTO PCI advocates like O Katoh, H Tamai and T Suzuki, who are
pioneers in the field of CTO intervention.
 Also, there is a shift in long-term patency from less than 50% to more than 90%
due to DES.

3. “Every interventionist
dreams of expertise in
CTO intervention which is
last niche in the field of
interventional cardiology”

4. Definition
 CTO is defined as a complete occlusion of a coronary artery
with TIMI 0 flow, for more than 3 months duration.
 The arbitrary duration of 3 months is used due to the
changes that ensue in the occluded segment during this
period (fibrosis, calcification, development of micro-
channels and bridging collaterals).
 These changes directly influence the success rate of PCI of
these lesions.
 Functional CTO unlike true chronic CTO shows antegrade
contrast filling of distal vessel in the absence of bridging
collaterals and without visible intraluminal contrast filling
of the occluded segment (TIMI I flow).

5. Pathology of CTO lesions
 CTO characterized by heavy atherosclerotic plaque- and thrombus .
 A tough, fibrous cap is often present at the proximal and distal margins of
the CTO.
 The density of the proximal fibrous cap is higher than that of the distal cap.
These obstructions are thus more likely to deflect guidewires into the
subintimal area, creating dissection planes.
 Hard plaques are more prevalent with increasing CTO age (>1-year-old). The
extent and severity of calcification increase with occlusion duration.

6.  Autopsy studies demonstrated neovascular
microchannels within CTO lesions—some
extending from the proximal to the distal lumen,
but others, leading to small side branches or vasa
vasorum in the vessel wall.

10. 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

11. Presentation
 Most patients p/w stable angina, a change in anginal
status, silent ischemia or heart failure of ischemic origin.
 More than 50% of patients with CTOs have well-
preserved LV function and more than 80% have no Q-
waves in the CTO territory, suggesting that the
dependent myocardium is viable.
 CTOs are one of the commonest reasons for referral for
CABG and many are left untreated because of
uncertainty regarding the procedural success and long-
term benefit.

13. Expertise and Financial burden
Broader access to operators performing CTO PCI is needed—the
safety and effectiveness of the more complex strategies are related
to operator volume and the ascension of a learning curve.
Adequate training programs and CMEs will need to continue to
be developed to broaden the pool of CTO operators.
Very few health-care and reimbursement systems value the time
and resource use that can be required for a successful CTO PCI
program.
The financial burden of performing CTO intervention is
high, particularly in our country where reimbursement
for CTO is equaled as simple angioplasty. CTO
intervention requires multiple devices with a chance of
failure. This situation creates problems when there is a
failure of recanalization of CTO.

14.  Japanese-CTO investigators have improvised the
techniques and innovations which lead to the safety
and effectiveness of CTO PCI.
 On the basis of the collective emerging data, it seems
that success rates of 80–90% with the contemporary
strategies and techniques are consistently achievable
in experienced hands with a safety profile comparable
to standard risk-adjusted PCI.

15. J-CTO Score

16.  The most common failure mode of CTO interventions
remains the inability to successfully cross the
occlusion with a guidewire.
 The retrograde approach through collateral channels
has been introduced to cross complex CTOs.
 Older occlusions, greater CTO length, a non-
tapered stump, the origin of a side branch of
the occlusion site, and calcification negatively
affect the ability to successfully cross a CTO.

22. Preprocedural planning
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 & side branch
calcification
details of collateral circulation
EURO CTO club;2012 consensus

23. 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

24. First inject donor – then occluded vessel – minimize
radiation
Septal collaterals best visualized –RAO cranial OR straight
RAO
LAO & RAO cranial – Best to image distal lateral wall
collaterals
(OM-PLV, diagonal to OM connections)
JACC intrvn2012;5:367-79

25. Repeat procedures – when to stop
Repeat procedures – More common with CTO
failure of a specific recanalization strategy
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

26. 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
Anticoagulation
UFH – ease of use & available antidote
Avoid bivaluridin &gp 2b 3a inhibitor
Brilakis et al,2012Korean Circ J 2010;40:209-215

27. Hardware for CTO

28. 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
Prox 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

29. Guide wires
Crossing 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
Most common reason for failed CTO PCI- failure of GW to cross

37. Microcatheters

38. Low profile,trackable OTW microcath - indispensable tool for CTO PCI
Allow ease of wire exchange
Facilitates transmission of torque to tip & improve feedback
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

42. Finecross microcath
terumois.com

43. Penetration Catheter
 Corsair microcatheter:
 This is a 2.7-F catheter with a lubricious outer
coating, a bidirectional wire braiding for torque
transmission, and an inner polymer lumen with a
soft tip for optimal wire control

45. Penetration catheter

48. Guideliner(Guidezilla)
 Known as guide extension catheter
 A GuideLinerTM catheter (mother and child technique):
 The “mother and child” technique is a powerful
technique used to provide additional backup force to
conventional guiding catheters.
 After crossing the lesion with a conventional guidewire,
the GuideLinerTM is used as an inner catheter and
inserted inside the 6 Fr.
 Guiding catheters, creating a “mother and child” system,
and can be used to intubate the coronary artery.

49. STRATEGIES AND
WIRING TECHNIQUES

50. 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;2:375-381Korean Circ J 2010;40:209-215

52. 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

53. 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

54. 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

56. Penetration
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
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

57. Penetration power = tip load/tip area
May use to redirect in conjunction with parallel wire technique

59. Approaches for CTO PCI

60. ALGORITHM FOR CROSSING CHRONIC
TOTAL OCCLUSIONS
After the dual coronary injection is performed, four
angiographies parameters are assessed:
1. Clear understanding of the location of the proximal cap using
angiography or IVUS.
2. Lesion length: Lesions more than 20 mm in length tends to have
lower success rates and longer procedure times.
3. Presence of branches, as well as size and quality of the target vessel
at the distal cap.
4. Suitability of collaterals for retrograde techniques: Optimal
collateral vessels for retrograde CTO PCI is sourced from a healthy
(or repaired) donor vessel.

61. GUIDEWIRE SELECTION AND
UTILIZATION
There are four important features regarding CTO wires:
1. Polymer covers: Plastic sleeves of flexible but solid material
that are applied directly over the core or over spring coils
covering the tip of the wire.
2. Wire coatings: There are two types, hydrophilic and
hydrophobic. There is an inverse relationship between
lubricity and tactile feedback related to the presence or
absence of coatings over coils and polymers at wire tips.
3. Core materials and tapering: The majority of CTO wires
has a stainless steel core.
4. Tip stiffness: This range from 0.5 g to 20 g. Tip tapering
strongly affects penetration power as the force is applied over
a smaller cross-sectional area in tapered wires.

62. Four-Wire Strategy
 Hydrophilic and/or polymer-jacket 0.014 inch guidewire, low
gram-force, with tapered 0.009 inch tip, for antegrade
microchannel or soft tissue probing—Fielder XT
 Nontapered, polymer-jacket hydrophilic 0.014 inch guidewire
for collateral channel crossing in retrograde procedures—
Fielder FC/Pilot 50
 Moderately high gram-force (4‒6g), polymer-jacket, non-
tapered 0.014 inch guidewire for complex lesion crossing, long
lesions—Pilot 200
 High gram-force 0.014 inch guidewire, with a tapered 0.009
inch nonjacketed tip for penetration techniques, cap
puncture—Confianza Pro 12 wires.

65. Antegrade Approach
 most used approach with success rates of 60–80% during the last 20 years.
 Tapered guidewires are first choice for this approach, including the Fielder XT.
 Recently, new tapered wires, such as the Gaia 1st have been developed and are
gaining acceptance. These tapered guidewires are not intended for intentional
crossing of the CTO by wiring and are designed for microchannel tracking,They
are not used to treat a CTO without microchannels and are unlikely to pass
through tortuous or kinked microchannels
 If the affected artery is tortuous, a tapered guidewire should be switched to an
immediate type of wire. The Miracle 3g, 4.5g, and 6g guidewires are
representative wires for this purpose.
 The Gaia 2nd guidewire (0.011 inch, Lifeline) was developed recently and it has
attracted the attention of leading interventional cardiologists. Because of its
excellent torque transmission, the Gaia 2nd is particularly efficient at passing
along tortuous arteries and entering fine channels.

66.  To rationalize a CTO in a relatively straight artery, a stiff wire can be
used to begin with. The Conquest Pro is a representative stiff guidewire
with better penetration than the other guidewires in this class.
 Increased risk of coronary artery injury, so the operator must make all
possible efforts to keep the guidewire within the vessel lumen and should
not choose this wire if the course of the vessel is difficult to visualize or
predict
 If the CTO is too dense to cross, the guidewire should be exchanged for
one with a stiffer tip such as a Conquest Pro 12 g or 20 g23
 The operator should not rotate the guidewire excessively as this may
enlarge the subintimal space. If a guidewire enters a subintimal space,
the wire will feel ‘‘trapped’’ and this can be confirmed by frequently
performing alternating withdrawal/advancement
 The operator should not forget to check multiple views of the CTO while
attempting to cross the lesion. It is important to check the CTO in two
views so as to keep the guidewire within the intimal space

67. Advance wiring techniques
for Antegrade approach

68.  In case of failure of the guidewire to enter the CTO
segment; many advanced techniques can be used.
 These should be used by either experienced
operators or under their supervision.
 These techniques include -
(1) parallel wire technique,
(2) antegrade subintimal dissection and reentry
(3) antegrade intentional intimal plaque tracking

72. Retrograde Chronic Total Occlusion
 Retrograde wiring is performed with a dedicated,
microcatheter-supported slippery guidewire from the
collateral-supplying vessel through the collaterals into
the distal vessel.
 Important modifications of the retrograde technique
have occurred since earlier descriptions, notably the
advent of the channel dilator (Corsair). Then, the
retrograde guidewire is steered proximally through the
CTO to the antegrade guiding catheter (retrograde wire
crossing technique).
 If the retrograde guidewire enters a false lumen,
controlled antegrade and retrograde subintimal
tracking (CART) technique can be used.

73. Stepwise approach for the retrograde
recanalization for CTO:
 Retrograde collateral channel access and crossing:
Nontortuous septal collaterals are preferentially used for the
retrograde approach, whereas epicardial and/or tortuous
collaterals are at higher risk of procedure-related vessel trauma
 Crossing the CTO: Successful channel crossing of the catheter
was achieved in 96.8%, and the channel dilator successfully
advanced into the occlusion reversely during retrograde wiring in
94.4%.
 Wiring the antegrade guide, snaring, and
externalization: Of the several available retrograde wiring
techniques, the reverse CART technique has become the most
commonly used technique in the Corsair era because retrograde
balloon access is not required

74. ADVANCE WIRING
TECHNIQUES FOR
RETROGRADE APPROACH

75.  However, still retrograde approach is not considered
as first-line approach and is reserved for prior failed
attempts of antegrade approach.

76.  Three possible routes to reach distal cap of a CTO:
 (1) through arterial or venous grafts anastomosed to the
distal vessel;
 (2) through epicardial collaterals and
 (3) through septal collateral channels.
 Septal collaterals are the preferred collaterals owing to
their shorter, less tortuous route and feasibility of
balloon dilation for facilitating device passage without
significant risk of perforation and tamponade.

80.  Hydrophilic soft-tipped floppy guidewires are ideal for negotiating these collateral channels.
 Use of microcatheter is mandatory to provide support to these floppy guidewires and allow precise
guidewire control by preventing flexion, kinking and prolapse.
 Various microcatheters such as Terumo FineCross ,however, the recently introduced Corsair
microcatheter (ASAHI Intecc Co. Ltd, Aichi, Japan) is more widely in use.
 Corsair microcatheter is a hydrophilic OTW system composed of eight thin wires wound along two
large wires. The narrow flexible tip and extreme lubricity of this microcatheter supported by a
strong metal shaft allows for gradual advancement along with simultaneous dilation of the septal
channel, obviating the need of balloon predilation.
 This microcatheter allows for rapid wire exchanges so that various guidewires can be tried, crucial
for procedural success.
 Corsair is slowly “screwed” through the collateral channel under the fluoroscopic guidance to reach
the distal bed of occluded vessel.
 Once the distal coronary bed is reached, the soft-tipped hydrophilic guidewire can be exchanged
for a stiffer guidewire to attempt penetration of distal fibrous cap.

82.  Retrograde strategies can be classified into four
major types :
1. Retrograde wire cross
2. Kissing wire cross
3. Controlled Antegrade and RetrogradeTracking
(CART)
4. Reverse CART.

86. Retrograde wire cross:
 Direct penetration of the distal fibrous cap may be easier than penetrating the more
resistant proximal cap .
 Once the microcatheter reaches the distal coronary bed, its tip is positioned as close
to the distal cap as possible.
 The choice of guidewire for penetrating distal cap is similar to that in the antegrade
approach. Initially a soft tapered wire (Fielder XT®, Runthrough NS® tapered) is
tried, if unsuccessful then dedicated recanalization wires like Miracle series with
gradual increase in tip stiffness can be tried.
 Due to the long course followed by the retrograde wire via a tortuous collateral
channel, its maneuverability is poor, and it is difficult to lead it through the CTO
lesion.
 As such the success rate of direct retrograde wire cross is relatively low and this
technique has been largely discontinued.

87. Kissing wire cross:
 Also known as marker wire technique,
 utilizes simultaneous combined use of the antegrade and retrograde approaches .
 The retrograde guidewire in the distal vessel serves as a marker of the distal CTO
location and aids in maneuvering of the antegrade guidewire until both meet (kiss)
each other.
 The retrograde guidewire can also help in antegrade wire cross by creating
intraluminal channel in the distal CTO portion. As the distal wire acts as an effective
marker, no additional contrast injection is needed during the manipulation of
antegrade wire; as such this technique is suited for patients with renal dysfunction
in whom contrast dose is limited.
 However currently this technique has fallen out of favor against the now preferred
CART technique, and is used only when CART cannot be performed due to failure of
bringing an OTW balloon catheter through the intercoronary channel.

93. Controlled antegrade and retrograde
tracking(CART):
 combines the simultaneous use of both antegrade and retrograde
approaches.
 A guidewire is advanced antegradely from the proximal lumen into
the subintimal space at the CTO site.
 After successfully crossing the collateral channels retrogradely, the
OTW balloon or the microcatheter is placed in distal true lumen.
 A selective contrast injection is made in distal lumen to define
anatomy of the distal cap. Depending on the anatomy of the distal
cap, either the same polymer-coated wire which was used to
negotiate the collateral channel or a stiffer wire is used to penetrate
into the distal CTO subintimal space.

94.  A balloon is advanced in retrograde fashion into the CTO subintimal
space and inflated to enlarge the subintimal space. The antegrade
wire is maneuvered ahead to seek this enlarged subintimal space
and subsequently cross to the distal true lumen .
 Over this antegrade wire the lesion is dilated and stented to
complete the revascularization procedure. Inability to negotiate
OTW balloons across the long and tortuous collateral channel is
main reason for procedural failure of this approach.
 Serial dilations of collateral channel or recently the use of Corsair
dilation catheter have obviated this problem to a certain extent. In
cases when there is inability to pass OTW balloons retrogradely
even after dilating the collateral channel, reverse CART technique is
utilized

98. Reverse CART:
 This technique is similar to the CART procedure, except that
the balloon dilation is done over antegrade wire to increase
subintimal space at proximal CTO site.
 The retrograde wire is then negotiated subintimally to seek
the proximally created subintimal space and thus cross to the
proximal lumen.
 Unlike CART procedure where subsequent balloon and stents
are delivered over the antegrade wire, this is not possible in
reverse-CART because of long and tedious course taken by the
retrograde wire.
 As such this technique involves an additional step of wire
externalization, so as to pass balloons and stents antegradely.

102. Intravascular ultrasound (IVUS) guided
reverse CART:
 Use of IVUS guidance can increase success of reverse
CART procedure. After dilating the balloon over the
antegrade wire in proximal CTO subintimal space, an
IVUS catheter is advanced antegradely in the subintimal
space. This IVUS catheter is used to assess the subintimal
space, visualize the connecting channel and aid the
guided crossing of retrograde wire into the proximal true
lumen.
 Confluent balloon technique: In confluent balloon
technique, balloon dilation is simultaneously performed
over both antegrade and retrograde wires to create a
common subintimal space, which facilitates easy wire
crossing to the true lumen.