1. Approach to CHRONIC TOTAL OCCLUSION
MODERATOR: Dr. P J BHATTACHARYYA, Dr. F Iqbal
PRESENTED BY: DR. S S. GARDE
Department Of Cardiology, GMCH

2. INTRODUCTON
• Clinically, a CTO imitates a lesion with a fractional flow reserve
(FFR) of .80 or less.
• Drug-eluting stent patency rates are approximately 90% at 1
year
• The essential challenge of CTO PCI lies in the initial traversing
of the lesion with a guidewire
• Success rate in current era is greater than 90%
Brilakis ES, Grantham JA, Rinfret S, et al: A percutaneous treatment algorithm for crossing coronary chronic total occlusions.
JACC Cardiovasc Interv 5:376–379, 2012.

3. Definition
• A CTO is most often defined as an occlusion known to be
present for 3 or more months or a newly documented
occlusion not attributable to a similarly recent ischemic event
with TIMI 0 FLOW.
Dangas, Mario, Kipshidze, Barlis, Addo:
Interventional Cardiology: Principles and Practice, 2nd Edition

4. Prevalence
• Fefer et al - 18% in Canadian registries
• Swedish Registry – 16 %

5. When to do CTO PCI?
• Evidence of Ischemia is must.(the primary indication for CTO PCI in the setting of single-
vessel CAD is the relief of ischemic symptoms that persist despite anti-ischemic medical therapy.)
• Clinically evident ischemia, reversible ischemia in non invasive testing
• Territory: myocardial supply at least 10% of the entire myocardium /viable
territory
• When the probable success rate is >60 % and and anticipated major
complication i.e MI<5% and Death <1%
Circulation 2003;107:2900-7

6. LEVEL OF RECOMMENDATION
• “The American College of Cardiology (ACC)/American Hospital
Association (AHA)/Society for Cardiovascular Angiography and
Interventions (SCAI) guidelines state that “(CTO PCI) in patients
with appropriate clinical indications and suitable anatomy is
reasonable when performed by operators with appropriate
expertise” (class IIa, level of evidence B) but do not further
define appropriateness.

7. Approach in various situations
• In stable angina with multivessel – CTO lesion should be
attempted first.
• In general when the CTO represents the only significant lesion
in the coronary tree , PCI is warranted.

8. IMAGING
• CORONARY ANGIOGRAPHY; simultaneous assessment of feeder
and recipient vessel.
• Coronary CT Angiography: lesion length, toruosity, vessel course,
stump morphology, presence of side branches, and presence of
bridging collaterals
• Intravascular ultrasonography: IVUS provides an axial spatial
resolution of 80–150 μm and therefore precise visualization of
lumen and vessel wall is possible

9. SIMULTANEOUS/DUAL ANGIOGRAPHY
• Dual-injection collateral analysis is best performed using low
magnification, so that the entire coronary tree is visualized without
panning.
• Careful study of the collaterals provides important information
– 1. in choosing the most appropriate collateral
– 2. alert the operator to the risk of ischemia and hemodynamic or electrical
instability if the wired collateral becomes occluded.
Brilakis ES, Grantham JA, Rinfret S, et al: A percutaneous treatment algorithm for crossing coronary chronic total occlusions.
JACC Cardiovasc Interv 5:367–379, 2012.

10. Views
• 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

11. Transseptals are the most commonly used
collaterals for retrograde chronic total
occlusion techniques and can
serve to access an occluded dominant RCA
or dominant LCX from the LAD, or in the
opposite direction, to access an occluded
LAD from a dominant right or left
circumflex artery.
Because transseptal collaterals are
generally contained within septal
myocardium, their rupture rarely poses a
hazard with respect to tamponade

12. large, dominant, tortuous, trans
pical epicardial collateral supplies
the right posterior descending
artery from the distal left anterior
descending artery.
This collateral is likely to become
kinked when instrumented with a
guidewire or microcatheter,
resulting in loss of visualization of
the distal target and creating the
potential for acute intraprocedural
ischemia.
Collaterals of this configuration are
rarely helpful as conduits for
retrograde access.

13. • Two typical atrioventricular
groove epicardial collaterals
from the circumflex artery to
the righ posterolateral
branch. Arrowheads indicate
a straight connection

14. CT ANGIOGRAPHY
• Most important use is to evaluate lesion length.
• Characterization of plaque.
• VESSEL anatomy within the occluded segment.
• Decreases time of radiation and contrast exposure.
Catheter Cardiovasc Interv.2006;68:1-7

15. IVUS
• ANTEGRADE APPROACH
– Identification of proximal cap location(IVUS CATHETER in side branch)
– Confirm the wire penetration in the prox cap
– Redirect wire into true lumen after penetrating subintimal space
– Optimizing stent placement
• RETROGRADE APPROCH
– Guiding wire into proximal lumen of the CTO.
Catheter Cardiovasc Interv. 2004;61:381-6

16. PREDICTORS OF CHRONIC TOTAL OCCLUSION-PERCUTANEOUS
CORONARY INTERVENTION SUCCESS

17. • Patients are classified into four difficulty groups:
– easy (J-CTO score of 0)
– Intermediate (a score of 1)
– difficult (a score of 2)
– very difficult (a score of 3 or higher)
• The J-CTO score correlated well with the probability of successful
guidewire crossing within 30 minutes (87.7%, 67.1%, 42.4%, and
10.0%, respectively) and was recently validated in an independent
single-center Canadian cohort

18. CTO SCORES
• The predictability of antegrade wire crossing success was
demonstrated to be marginally better with the W-CTO score as
compared to the J-CTO score .
• These CTO score helps in assessing the success rate and should
be applied by operators
Nombela-Franco L, Urena M, Jerez-Valero M, et al: Validation of the J-chronic total occlusion score for chronic total occlusion
percutaneous coronary intervention in an independent contemporary cohort. Circ Cardiovasc Interv 6:635–643, 2013.

19. Preprocedure planning
• Paramount importance – planning reduces difficulties half way
through the procedure
• Spend time examining diagnostic films or angiogram & 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
• Contrast volume defined prior to procedure - 4xGFR(ml)
• EURO CTO club;2012 consensus

20. RULES
• Coaxial hooking of the Guiding catheter
• Absolute sure position of G/W
• Advancing guide wire with support of microcatheters, and step up
approach.
• Adequate Support from guiding catheter
• Right – AL1
• LAD- XB, EBU
• PROX LCX- AL2 OR 3
• Larger G/C- 8F
• Ostial Lesion – Large diameter with less aggressive shape

21. There are three major techniques for crossing CTO
lesion:
• (1) antegrade wire escalation
• (2) antegrade dissection re-entry
• (3) retrograde approach.
• According to the angiographic characteristics of occlusion the
type of approach can be selected .

22. ALGORITHM

23. PROCEDURAL ANTITHROMBOTIC THERAPY
• WITH HEPARIN
– ANTEGRADE : ACT >300 seconds
– RETROGRADE : ACT >350 seconds

24. GUIDE WIRES AND MICROCATHETERS
• Penetrating proximal cap > traversing body > penetrating distal fibrous cap.
• 1. polymer coated g/w(hydrophilic) 2. Non polymercoated(non hydrophilic)
• HYDROPHILIC G/W – MANUEVERABILITY, cost of dissection
• NON HYDROPHILIC GUIDE WIRES – stiffer, better tactile feel, control, less dissection
• MICROCATHTERS or OTW balloon cathters : OTW, low profile(1.2 or 1.25 mm), (
support and exchangeing wires)
– TORNUS
– CORSAIR (most commonly used in retrograde PCI), NAVIGATE THROUGH VERY ANGULATED AND
SMALL CALIBER COLLATERALS.
Indian Heart Journal 68 (2016) 450–463

26. Indian Heart Journal 68 (2016) 450–463

27. Guidewire Strategies For Approaching Occlusion
• A) Micro channels
– Crosswire, whisper/pilot, shinobe, ChoICE PT/PT ES
– PT graphix, PT2
• B) Drillling
– Persuader, Miracle Bros, Cross-2
• C) Penetrating
– Cross IT, Conquest Pro, Liber 8, confianza pro
• D) Retrograde
– Fielder XT/FC, X treme, Whisper, ChoICE PT2, Runthrough,
Hypercoat

28. Indian Heart Journal 68 (2016) 450–463

29. STRATEGIES
• ANTEGRADE
• ANTEGRADE DEVICE ASSITED DISSECTION REENTRY
• HYBRID
• RETROGRADE TECHNIQUES
– CART( controlled antegrade and retrograde subintimal tracking)
– REVERSE CART

30. ANTEGRADE WIRE TECHNIQUE
• most common approach worldwide
– Parallel wire technique
– STAR (subintimal tracking)
• over-the-wire catheter is delivered to the proximal cap on a
workhorse wire, and then CTO-specific techniques and wire
shaping are applied( angle <30 deg, 1 mm from tip)
• approach of gradually escalating wire stiffness to achieve
crossing
Cardiovascular Intervention; Deepak L bhatt ; 2ND EDITION

31. • starting the wiring procedure with a soft tapered tip wire like Fielder XT/
XTR and changing to an intermediate-stiffness guidewire like Fielder XTA or
Gia 1 or Gia 2
• tapered tip wire is more likely to enter loose connective tissue and once
entered an intermediate wire will automatically track the tissue with low
resistance rather than penetrating into the hard atherosclerotic plaque.
• This concept is supported by the PIKACHU trial (Prospective Multicenter
Registry of IKAzuchi-X for Chronic Total OcclUsion) where approximately
70% of CTOs could be crossed with an intermediate-stiffness 0.010 inch
hydrocoated wire.
PIKACHU registry. Catheter Cardiovasc Interv. 2010;75:1006-12

32. ANTEGRADE WIRE TECHNIQUE
• once G/W access the distal true lumen, the CTO-crossing wires
should be exchanged for workhorse wires to avoid distal
plaque disruption/dissection and in particular to prevent
inadvertent distal perforation of small vessels, causing delayed
tamponade

33. ANTEGRADE WIRE TECHNIQUE
• In the parallel wire method, a wire which enters the subintimal
space is left there, and a second wire is inserted alongside to find a
new channel.
• When this technique is successful, the following findings are often
noted:
• (1) the second wire crosses over the first inside the CTO;
• (2) the second wire shows more acute curve than the first wire;
• (3) the second wire penetrates the lesion from the outer curvature of the coronary
artery and then is advanced along the same curvature of the vessel

34. ANTEGRADE DISSECTION/REENTRY(device assisted)
• CrossBoss catheter, Stingray balloon, and Stingray reentry
guidewire (Boston Scientific, Natick, MA) have addressed mode
of failure when recanalizing a chronically occluded vessel (failure
of the wire to enter the distal true lumen and to instead reside within plaque or
within the subintimal plane)

36. RETROGRADE APPROACH(15-20%)
• CART AND REVERSE CART
• Dual angiography
• CHOOSING collateral is the first key step.
• usually of small caliber (100–200 μm) and often present a tortuous
course making them fairly vulnerable.
• Crossing collaterals with Sion, Fielder or Pilot 50 G/W (soft tipped)
and corsair microcatheter
• RETROGRADE lesion crossing
• Using of subintimal space for balloon inflation.
Catheter Cardiovasc Interv. 2007;69:826-32

37. • Controlled antegrade-retrograde tracking (CART).
Through directed penetration or knuckling, antegrade
and retrograde guidewires are brought into overlap
within the occluded segment
• [1]; wires may be on opposite sides of the internal
elastic lamina (one subintimal, the other within the
occluded true lumen [1a]; both within the occluded
true lumen [1b]; or both in a subintimal plane [1c]).
• Regardless, a balloon is advanced over one of the
wires [2];
• it is inflated and deflated [3];
• and it is then withdrawn, leaving behind iatrogenic
dissection that often includes breaches of the internal
elastic lamina within the occluded segment [4] that
allow the retrograde wire to be moved into a plane
common with the antegrade wire and then advanced
into the patent proximal true lumen [5] and ultimately
externalized.
• CART was originally described with the balloon
positioned on the retrograde wire; the term reverse
CART refers to the now common practice of
positioning the balloon on the antegrade wire.

38. REVERSE CART
This tears (dissects) together the two spaces occupied by antegrade and retrograde equipment to
create a single, common space that is in continuity with the proximal true lumen; the retrograde
wire can then be advanced into the true lumen.
The most common reason for failure of this technique is use of undersized balloons, a problem
overcome with experience and use of IVUS for optimal balloon sizing and positioning

39. HYBRID APPROACH
• Switching over from antegrade to retrograde and vice versa
• Hybrid method; CTO PCI success >90% (Am J Cardiol 112:488—492, 2013)
• The hybrid approach limits the variablity and standardizes
based on the following lesion characteristic
– Lesion length >20 mm
– Proxmal CTO cap ambiguity
– Presence of interventional collaterals
– Suitability of the distal vessel for targeted entry

40. “Wire Crossed Balloon Not Crossed”—What Next?
• often observed in chronic calcific CTOs.
• usually approached with a combination of lesion modification
techniques (such as use of microcatheters and multiple balloons) and improving guide
support, (use of anchoring techniques and use of guide catheter extensions).
• Other techniques include advancing a microcatheter or Tornus
antegradely which creates a small channel over which a small size
(1.2 mm × 6 mm) balloon could then advance.
J Am Coll Cardiol Intv. 2009;2: 479-86

41. “Wire Crossed Balloon Not Crossed”—What Next?
Balloon intervention
• the initial step is to advance and inflate to high pressure a small
(1.2 to 1.5 mm in diameter, 14 to 16 atm) balloon as deeply as
possible within the lesion to modify the proximal cap.
• When using small balloons, it is important to use longer balloons
(15 to 20 mm) because the largest profile of these balloons is at the
midshaft marker, and thus the balloon tip will often penetrate the
occlusion more readily.
• If this fails to allow passage of larger balloons, the next maneuver is
to intentionally rupture the small balloon so as to modify with
barotrauma the morphology of the proximal vessel and cap.

42. 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
J Am Coll Cardiol Intv. 2009;2: 479-86

43. COMPLICATIONS OF CHRONIC TOTAL OCCLUSION-
PERCUTANEOUS CORONARY INTERVENTION
• death 0.2%,
• emergent CABG surgery 0.1%
• stroke less than 0.01%
• MI 2.5%
• coronary perforation 2.9%
• tamponade 0.3%
• contrast nephropathy 3.8%
• in a series by Patel et al. compared with successful procedures, unsuccessful
procedures had higher rates of death (0.42% vs. 1.54%; p <0.001)
Patel Y, Depta JP, DeMartini TJ. Complications of chronic total occlusion
percutaneous coronary intervention. Interv. Cardiol. 2013;5(5):567-75

44. When Not to do Chronic Total Occlusion?
1. if two or more major vessels have a CTO
2. CTOs are present in sequence in same vessel
3. a small vessel with CTO is not worth the effort
4. a very long CTO with heavy calcification
Dangas, Mario, Kipshidze, Barlis, Addo:
Interventional Cardiology: Principles and Practice, 2nd Edition

45. 5. very tortuous CTO anatomy with heavy calcification of vessel
6. a CTO from ostium of artery
7. CTOs distal to complex proximal vessel lesions, e.g., CTO of
LAD beyond a severe/moderate LM bifurcation stenosis or
CTO of CX/OM beyond an ostial CX calcific stenosis.
8. Retrograde approach to do CTO-PCI should not be used if
donor artery is heavily calcified or with mild or moderate long
segment disease which otherwise would not need anything to
be done or would risk donor artery closure.
When Not to do Chronic Total Occlusion?
Dangas, Mario, Kipshidze, Barlis, Addo:
Interventional Cardiology: Principles and Practice, 2nd Edition