Coronary CTO is characterized by heavy atherosclerotic plaque burden within the artery, resulting in complete (or nearly complete) occlusion of the vessel. Although the duration of the occlusion is difficult to determine on clinical grounds, a total occlusion must be present for at least 3 months to be considered a true CTO. Patients with CTO typically have collateralization of the distal vessel on coronary angiography, but these collaterals may not provide sufficient blood flow to the myocardial bed, resulting in ischemia and anginal symptoms. CTO is clinically distinct from acute coronary occlusion, which occurs in the setting of ST-segment–elevation myocardial infarction, or subacute coronary occlusion, discovered with delayed presentation after ST-segment–elevation myocardial infarction. Clinical features and treatment considerations of these entities differ considerably from CTO. Among patients who have a clinical indication for coronary angiography, the incidence of CTO has been reported to be as high as 15% to 30%. Patients with CTO are referred for angiography because of anginal symptoms or significant ischemia on noninvasive ischemia testing. Patients who are symptomatic will have stable exertional angina resulting from a limitation of collateral vessel flow to meet myocardial oxygen demand with stress. Of patients referred for PCI in clinical trials of CTO PCI, only 10% to 15% of patients are asymptomatic. It is likewise uncommon for patients with CTO to present with an acute coronary syndrome caused by the CTO itself.

1. Chronic total occlusion of
coronary artery
Durga Pavan
Nizam’s Institute of Medical Sciences, India

2. For a layman

3. DEFINE
• >99% stenosed
• Duration >3 months
• TIMI 0-1

4. Histopathology
• Organized thrombus.
• Fibrotic plaque
• Calcified lesions.
• Proximal/ distal fibrous cap
• Micro channel in the occlusion segment

8. Micro channel inside the occlusion
• Often extend to small side branch & to
adventitia
• Extravascular micro channels in early phase of
occlusion
• More mature CTO –intravascular channels
increase
• Matured CTO - both fewer
• Longitudinal continuity – 85% of entire length
of CTO

10. Benefits of CTO-PCI
▫ Symptom relief,
▫ Improvement in left ventricular function,
▫ Improve tolerance of a future acute coronary
syndrome
▫ Reduce the need for coronary artery bypass graft
surgery
▫ Better long-term survival.

11. Symptom relief
• TOAST-GISE (Total Occlusion
An-gioplasty Study–Società
Italiana di Cardiologia Invasiva)
trial, CTO-PCI success - 86%,
CTO-PCI failure - 70% ,
angina-free survival (p=0.008)
• Cheng et al. Demonstrated
that 76% of patients with CTO
who were treated with PCI
experienced an improved
angina classification, whereas
17% of patients who were not
treated with PCI improved
(p<0.05).

13. • A 3.8% to 8.4% absolute reduction in mortality
was associated with successful versus failed
CTO-PCI.
Survival advantage

15. • Symptoms
▫ A CTO with well developed collaterals is hemodynamically
similar to 90% coronary stenosis without collaterals –
significant recovery of ventricular function is expected
• Viable myocardium
▫ Recovery of LV function depends on the presence of
hibernating viable myocardium
• Success
▫ If the likelihood of success is moderate to high (>60%)
and the likelihood of complications less, PCI is
encouraging.
Patient selection

16. Barriers
• Complications
• Failure rates
• Economic burden
• CIN

17. Complications
• Impairment of collateral flow
▫ spasm, shearing off side-branches and collateral by
dissection, distal embolization
• Dissection with branch occlusion & Perforation
▫ intra-wall balloon expansion, side-branch dilatation,
damage of neochannels connecting vasa vasorum
• Guidewire entrapment
• Subacute vessel reocclusion
▫ 8% of total occlusion within 24hr Vs. 1.8% of non total
occlusion
• CIN
• Radiation

18. Reasons
• Not able to cross guidewire – 63%
• Long intimal dissection – 24%
• Dye extravasation – 11%
• Balloon did not cross or dilate – 2%
• Thrombus – 1.2%
Kinoshita I, et al. JACC 1995;26:409-411

19. Predictors
• Clinical-
▫ Duration - >3-6 monthS
▫ CRF
• Angiographic
▫ Calcification(at entry point/at distalcap)
▫ Blunt stump
▫ >45 angulation of target vessel
▫ Length of occlusion >15-20mm
▫ Vessel <3mm
▫ Multiple lesions in target art
▫ Lack of distal vessel filling
▫ Bridging collaterals and side branch

20. Predictors of success or failure in PCI of CTO
Predictors of success
Duration < 3 months
Antegrade flow +
Tapered morphology +
Bridging collaterals –
Side branch –
lesion length < 15 mm
Single vessel disease
Predictors of failure
Duration > 3 months
Antegrade flow –
Tapered morphology –
Bridging collaterals +
Side branch +, ostial lesion
lesion length > 15 mm
Multi vessel disease
Vessel & lesion tortuosity &
calcification
Bridging collaterals are more common
in lesions > 3 months old. Extensive
bridging collaterals that form caput
medusae around the occluded vessel
are generally not suitable for PCI

21. Predictors of Procedural SuccessTOAST - GISE

22. PROCEDURAL SUCCESS

23. Economic burden
• 2 procedure
• Fluoroscopy
• Hardware more

24. 4 angiographic parameters
• Location of the proximal cap using
• Length
• Side branches
• Target vessel at the distal cap
• Collaterals for retrograde techniques.

26. Two injection same time
• Collaterals to the distal target vessel.
• Lesion length and the size and location of the
distal target vessel, evaluating whether there is a
significant bifurcation at the distal cap, and for
deciding on the optimal CTO PCI strategy

27. Collaterals Assessment
• CAG
▫ Visible collaterals of 0.3-0.5mm
▫ <100 micro m are not visualized
▫ Selective using micro catheters

28. Collaterals grade[Rentrop]
0 1 2 3
Visible filling of
any collateral
channel
Filling of the side
branches of the
occluded artery,
with no dye
reaching the
epicardial
segment
Partial filling of
the epicardial
vessel
Complete filling of
the epicardial
vessel by
collaterals

29. Collaterals -Levine etal
▫ Septal
▫ Intra arterial (bridging)
▫ Epicardial
 Proximal take off
 Distal takeoff

30. Collaterals

31. Werner et al
• 3 grades
▫ CC0-no continues connection
▫ CC1 - continuous , threadlike
▫ CC2 – continuous , small side branch like

32. CT angiogram
• Procedural success
• Distal vessel
• Collateral
• Best angle for PCI approach

33. IVUS
• Entrance
• Subintimal vs true lumen

34. Guide catheter
• First key to success
• For effective guide wire manipulation :
▫ coaxial orientation of guide catheter important
▫ stability& back up force
• RCA - AL1/0.75 with side holes
• Shepard crook RCA - AL1or2
• Prox RCA lesion - JR ( avoid ostial damage)
• LCA - Extra back up(XBU,EBU,)
• LCX (short left main) - AL1 or2 (better support
& co-axial)

35. Guide catheter
• 7F or 8F guide catheter
▫ Superior backup support (needed in CTO)
▫ Inter twining is less common while using parallel wires
▫ Switching over to devices like rotablator is easy
▫ Permit better contrast injection.
So, radial approach is not preferred for CTO.
• Side hole guide catheter is useful for RCA
▫ Maintains perfusion to the sinus node artery & conus
branch

36. CTO wires

38. Fielder XT wire (Asahi Intec, Nagoya, Japan) and Run-
through taper wire (Terumo Corporation, Tokyo,Japan)
▫ A hydrophilic and/or polymer-jacket
▫ 0.014-inch guide wire,
▫ Low gram-force
▫ Tapered 0.009-inch tip
• Antegrade micro channel or soft tissue probing
and also for knuckle techniques.

39. Fielder FC wire (Asahi Intecc) and Pilot 50 wire (Abbott
Vascular,Santa Clara, California)
▫ Polymer-jacket hydrophilic
▫ Non tapered
▫ Low stiffness
▫ 0.014-inch guide wire.

40. Pilot 200 guidewire (Abbott Vascular).
▫ Polymer-jacket
▫ Moderately high– gram-force (4 to 6 g),,
▫ Non tapered
▫ 0.014-inch guide wire.
• For complex lesion crossing, long lesions,
knuckle technique, and dissection/re-entry.
• Performs well in very tortuous segments with an
ambiguous course

41. Confianza Pro 12 wire (Asahi Intecc).
▫ High– gram-force
▫ Non jacketed tipped
▫ 0.014inch guidewire,tapered 0.009-inch guide
wire.
• Penetration techniques, cap puncture, complex
lesion crossing, and lumen reentry techniques.
• Best used when the vessel pathway and location
target coronary segment are well understood.

42. Hydrophilic wires
• Slippery upon contact
with blood
• Useful in lesions with
visible channels.
• Excellent for markedly
tortuous lesions
• Can easily find way in
to a false lumen with
less tactile feed back 
intimal dissection &
proceedural failure or
even perforation &
tamponade
• They are less steerable
 Asahi Fielder (Abott
Vascular)
 Asahi Prowater (Abott
Vascular)
 Whisper – Guidant
 Pilot – Guidant
 Shinobi – Cordis
 Choice PT (Boston
scientific)

43. Stiff guide wires
• Non hydrophilic coil tip
designed to facilitate
the penetration of
distal or proximal cap.
• Stiff guide wires are
particularly useful
when proximal fibrous
cap is hard. (esp. the
tapered tip wires)
• Gradual step up
approach using wires
with increasing
stiffness is useful.
• Cross-IT
• Conquest
• Miracle

44. Tapered tip

45. Tapered guide wire
• Technical success: 76%
• Success rate in visible micro channel
▫ Incomplete micro-channel: 81%
▫ Micro-channels with distal filling: 100%
Buettner HJ, et al. JACC
2002;39:30A

47. Micro catheters
• Wire exchange[floppy to dedicated stiffer]
• Torque to tip & improve feedback
• Tip stiffness of guide wire

48. Corsair micro catheter (Asahi Intecc)
• 2.7-F catheter with OTW hybrid catheter
• Both micro catheter and support
• Bidirectional wire braiding for torque
transmission, and an inner polymer lumen with
soft tip for optimal wire control
• Cross collateral channels and provides the
primary basis for conventional retrograde
procedures.
• Super selective injection for collaterals
• Antegrade direction for wire support.

49. The Corsair catheter is advanced by rotation in either direction.
The Corsair should not be over-rotated (10 consecutive turns without
release) as over-rotation could cause catheter kinking

50. Tornus micro catheter (Asahi Intecc)
• Braided-wire mesh OTW microcatheter with left-
handed thread allowing for channel preparation and
lesion crossing in resistant occlusions.
• Advanced using counterclockwise rotation and
removed using clockwise rotation.
• Guidewire should remain within the Tornus inner
lumen during manipulations, and over-rotation
should be avoided to minimize the risk of kinking.
• Contrast injections should not be performed
through the Tornus, as the contrast escapes through
the wire braid.

52. Lesion crossing and lumen re-entry
technologies
• CrossBoss catheter (BridgePoint Medical,
Plymouth, Minnesota)
• Stingray balloon and Stingray guidewire systems
(BridgePoint Medical).

53. Precautions
▫ Covered stents
▫ Embolization coils
▫ Pericardiocentesis trays
▫ Thrombectomy devices

54. STRATEGIES
Antegrade approach
Retrograde approach
▫ SINGLE WIRE
▫ DOUBLE WIRE
 Parallel wiring
 Seesaw wiring
 Subintimal tracking and
reentry
 IVUS guided approach
 Retrograde wire crossing
 Kissing wire technique
 Knuckle wire technique
 CART
 Reverse CART

55. Next wire
• 1. Floppy wire as the 1st wire
• 2. Intermediate or MIRACLE 3
• 3. MIRACLE 6
• 4. MIRACLE 12 or Conquest Family

56. Stepwise
• 1.Atraumatic, tapered, hydrophilic FIELDER XT
• 2.Stiffer, tapered wire like CONFIANZA9/
MIRACLE6
• 3.Step down to softer wire

57. • Wire shaping
1ºbend of 30-45º
1-2mm from tip
Find softest part
2ºbend-10-15º
@3-6mm
Work as a navigator
to orient tip

58. Tip curve should be just larger than lumen diameter
CTO, the lumen diameter = 0 mm
For CTO lesion – Guide wire-tip curve should be very small
Larger curve may hurt the vessel wall during direction control

59. Guide wire negotiation
• Different methods
• Sliding AT proximal cap
• Drilling inside CTO
• Penetration Distal cap
• Micro channel tracking

60. •Simultaneous rotation & probing of lesion
•High chance of entering to subintimal space ( tactile
response - nil )
SLIDING
•Recent occlusion
•Predominance of micro channels
•Extremely low friction wires for picking micro channels
used
• Recent total, subtotal occlusion ,ISR attempted with this
strategy
•Long duration – Micro channels replaced by fibrotic
tissue

61. 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

62. 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 stiffness
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

64. 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

65. Penetration power = tipload/tiparea

66. • Tactile sensations
▫ Feeling of the dimple at the entry point,
especially in the abrupt type of CTO entry
▫ Feeling of strong resistance when pulling back
the wire inside the CTO body, such as when
the guide catheter is drawn into it—in this situation,
the
wire tip has most likely migrated into the subintima
▫ Feeling of no resistance the wire tip moves
freely—this most likely means that the wire tip is
either in the true lumen or in the extravascular space

67. Anchoring wire technique
▫ Guiding catheter is unstable
▫ One wire is positioned in a prox side branch
▫ Other wire for crossing of the occlusion

68. Anchoring wire
• Side branch protection
▫ Occlusion is long/ distal to side branch
• Correction of tortuousities
▫ Proximal tortuousities
• Buddy wire technique
▫ Facilitate passage of stent in complex leisions
▫ Serves as rail

69. Double wire
• Parallel wire technique

70. 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

71. See-Saw Wiring

72. See-Saw Wiring
• 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

73. Side branch technique

74. Success
• (1) Angle between direction in which the wire
lies and the bifurcating side branch is less than
90°;
• (2) Side branch less than 1mm;
• (3) No diffuse plaque build-up about the true
lumen in the distal portion of the CTO
• (4)True lumen to the ostium of the side branch,
the wire must be just to the side of the true
lumen in the distal part of the CTO

75. Open sesame technique
• Hard plaque
• Failed even with conquest pro 8-20
• Side branch just in front of proximal cap
• Pass stiff guide wire and/ or a balloon into side
branch.
• Distortion of geometry
• Enables guide wire to advance into true lumen.

78. Dissection reentry techniques
• STAR -Uncontrolled
• LAST - Somewhat controlled
• Dedicated systems -Controlled

79. • 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
STAR Technique

82. Knuckle wire technique
•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

83. Cross Boss catheter
• Metal OTW micro catheter 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

85. Sting ray balloon & guide wire system
1mm flat balloon with 3 exit ports connected to the same lumen
Distal exit port – for balloon positioning
Uses guide wire with extreme tapered tip (0.0025) for reentry
Distal true lumen entry confirmed by contralateral injection

87. RETROGRADE APPROACH
• Initially used after a failed antegrade approach
• Now used as initial strategy in challenging cases
▫ Ostial occlusion
▫ Large side branch at proximal cap
▫ Long occlusion (>30mm)
▫ Severe tortuosity or calcification
▫ Without stump
▫ Visible continuous collaterals

88. 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

89. Hydrophillic polymer jacket wire with <1mm 30-45º tip used
to cross recipient artey
Fielder FC,Pilot-50,Whisper, Choicept,Runthrough
Wire should move freely - difficulty to advance – perforation?
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

90. 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

91. 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

92. 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

94. • 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 collateral 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
C A R T Controlled antegrade & retrograde subintimal tracking

95. 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

97. 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

98. 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

100. 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

105. Antegrade vs retrograde

106. 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

107. APPROACH

110. 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

111. •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 cross sectional image into 3D needed
b) 2nd stiff tapered wire over micro catheter - 8f guide mandatory
c) Reentry point should be closer to proximal cap
d) Contrast injection should be withheld esp after small ballon
dilatation

114. Farword looking IVUS

115. Farword looking IVUS

116. Farword looking IVUS

117. Optical coherence reflectometry

121. n

130. Debulking of calcific lesion
• Rotational atherectomy
• Directional atherectomy
• Silverman plaque excision system

131. Collagenase plaque digestion

132. Magnetic navigation
• Magnetic navigation wire
• Stereo taxis Magnetic Radio Frequency Guide
wire
• Magnetic navigation micro robot

135. Complications

136. CTO=CIN

137. Into pocket diary
CTO-PCI IS SAFE

138. This Diwali -2014
NO CRACKER