Chronic Total Occlusion (CTO) - Dr Hafeesh Fazulu - Pushpagiri - May 2021

1. CHRONIC TOTAL OCCLUSION
(CTO)
Dr Hafeesh Fazulu
PUSHPAGIRI CARDIOLOGY
Pushpagiri Institute of Medical Sciences
Thiruvalla, Kerala.
+91 9995706688

2. Theory Exam Questions

3. Books to read

4. Websites
• www.progresscto.org
• www.ctomanual.org

5. 2019
Circulation

6. How does it look like on an angio?
With collaterals

7. Walking in the dark with a lamp

8. Definition of CTO
• Coronary occlusion (>99%) known to be present for 3 or more months
• OR
• A newly documented occlusion NOT ATTRIBUTABLE to a similarly
RECENT ischemic event
• Term OCCLUSION
• No visible continuous LUMEN
• No visible antegrade flow (TIMI grade 0)

10. Diagnosing CTO ?
• Collaterals
• Vs
• Acute occlusion

11. Stages

13. CTO vs STO (Sub total occlusion)

14. Histopathology of CTO
• Vessel architecture is preserved
• Favaouring revascularisation with CTO techniques

15. Negative remodelling Dystrophic calcium deposition

16. Indications for revascularisation in CTO
• Eg SVD with CTO
• KEY INDICATION IS TO IMPROVE SYMPTOMS
• If symptomatic with maximum medical therapy
• REVASCULARISATION is indicated

17. FACTORS TO CONSIDER for CTO
• Patient related factors
• Significant Symptoms
• LV Dysfunction with viable myocardium
• Co morbidities- general condition, renal function
• Lesion specific factors
• Single vs. multivessel
• Distal vessel
• Diameter of the vessel
• Main vessel vs. branch

18. • Operator dependent factors
• Exposure
• Experience
• Enthusiasm
• Energy
• Emotions

19. • Factors related to people around
• Radiation, Radiation, Radiation
• Colleagues –Availability of a colleague around who is free to help you
in need
• Lab time – arrange the procedure according to others convenience
too

20. • Financial Factors
• Patient related
• Hospital related – use of costly hardware

23. How difficult is it to do?
SCORING SYSTEMS

24. J-CTO Score
• Japan
• To predict the difficulty for CTO intervention
• Predicts the likelihood of successful wire crossing within 30 min..

26. Which scoring is ideal for me to do first ?
OPERATOR
Beginner Intermediate Advanced

28. PROGRESS-CTO SCore

29. https://www.progresscto.org/cto-scores

30. Other scores

31. Reading ANGIOGRAM
for CTO

32. • Most important factor in procedural success
• Selection of patient
• Selection of strategy
• Selection of guide catheter
• Selection of guide wire
• Identification of distal vessel and possible collateral channels for
retrograde approach

33. POINTS TO SEE in ANGIOGRAM
• Micro channels
• Entry point
• Side branch
• Island inside occlusion
• Calcium
• Tortuosity of occluded segment. - MS-CT helps.
• Exit angle

36. Collaterals

37. Sources of Collaterals

38. Which collaterals are better ?

39. Werner Classification

41. Favourable Collaterals

42. Collaterals can be DYNAMIC

43. Contralateral Injection (Dual injection)
• Do routinely
• Visualize distal vessel
• Assess occlusion length
• Assess possible collaterals in case of an
immediate switch to retrograde
technique
• Tip to reduce dye in renal impairment:
use selective injection through contra lateral micro
catheter

44. How to do ?
• First inject the DONOR vessel
• Wait for dye to reach the collaterals
• Then inject the CTO Vessel
• Cine until the contrast clears

45. Dual injection

46. Illustration of using two 4 Fr diagnostic catheters through an 8 Fr sheath (A) and a
dual angiogram obtained using this technique

47. Benefits of Dual injection – BEFORE PCI
CTO Characteristics
Injection of the left main coronary artery demonstrates a proximal circumflex CTO (A), but the characteristics of the lesion
remained unknown. Using dual injection (B) the characteristics of the CTO (proximal cap ambiguity, lesion length, bifurcation
at distal cap, quality of distal vessel, and presence of collaterals) were clarified.

48. Benefits of Dual injection – BEFORE PCI
CTO Characteristics - MICROCHANNEL
Injection of the right coronary artery revealed a distal right coronary artery occlusion (A), but the length of the occlusion and
the quality of the distal vessel could not be determined. Dual injection (via the right coronary artery and the left internal
mammary graft that supplied collaterals to the right posterior descending artery) demonstrated a microchannel (B) at the
occlusion site, very short occlusion length, and diffusely diseased distal vessel.

49. Benefits of Dual injection – DURING PCI
POSITION OF GUIDE WIRE
The guidewire appeared to be in the right posterior descending artery (PDA; A), but was actually in a proximal side branch
(B). Dual injection allowed correction of guidewire position before balloon inflation and stent deployment.

50. TIMING of the procedure

51. ANTICOAGULATION

52. ACCESS
• 2 access usually required
• Femoral – Radial
• Femoral – Femoral
• Radial - Radial

53. Triple access
• Rarely
• Eg
• RCA CTO with distal filling via the LAD, which
is supplied by a LIMA graft

54. EQUIPMENT

55. • Sheaths
• Guide Catheter
• Guide Catheter extensions
• Microcatheters
• Dual Lumen Catheters
• Wires
• Crossboss / Stingray System
• Snares

56. • CTO Balloons
• IVUS, OCT
• Rota, Laser, IVL, OPN Balloons
• Mechanical Circulatory Support – IABP, ECMO, Impella, Tandem Heart
• Access Closure Devices

57. • Managing Complications
• ECHO
• Covered Stents
• Coils, Gelfoams, Thrombin
• CVTS Surgeon and his team.

58. CTO Cart

61. SHEATH

62. • Large LONG Sheath
• B/L femoral 45 cm long sheaths
• Long sheaths straighten iliac vessel tortuosity
• Long sheaths reach till the tip of diaphragm
• Longer sheaths cause thrombosisd

63. • RADIAL ACCESS
• 6 F
• 7 F
• 8 F

64. GUIDE CATHETER

65. GUIDE CATHETER
• Dual 8F Catheters – most commonly used
• DONOR VESSEL – 6F
• Reduces trauma and risk of dissection
• Antegrade – 8F
• Retrograde – 6F

66. Short Guide Catheter. Why ???
• Retrograde catheter should be short
• Reduces the distance that a retrograde wire need to cover to be
externaliseddd

67. Shortening the Guide
catheter manually

68. Y Connectors

69. • Hemostatic valves
• To prevent blood loss

70. GUIDE CATHETER
Extensions

71. Uses of a Guide extension
1. Equipment delivery
2. Coronary engagement
3. Thrombectomy
4. Retrieval of entrapped equipment
5. Revert CART
6. Antegrade Dissection & reentry
7. KAM Snare / Homemade snare

72. • Consists of
• Push Rod
• Distal Cylinder
• Guideliner 25 cm
• Trapliner 13 cm
• Inner diameter is approximately 2 Fr smaller than guide catheter

73. Guideliner

74. Trapliner

75. Guidezilla II

77. Guidion

79. Microcatheters

82. Corsair and Corsair PRO
(A) Overview
(B)construction of the Corsair
microcatheter.
(C) The flexibility of the Corsair
catheter distal tip

83. • Corsair PRO
• Radioopaque marker removed for better trackability
• Tip flexibility increased

85. Caravel

86. Finecross

87. Micro 14

90. GUIDEWIRES

91. • Extensive list
• But must have ….

92. Algorithm for guidewire selection

93. Fielder
• FC – nontapered tip
• XT – tapered tip

94. Fielder XT-A and Fielder XT-R
• A – slightly stiffer 1.0 gm
• R – slightly softer 0.6 gm

95. Fighter
• Even stiffer – TIP LOAD 3gm

96. MIRACLEbros 3

97. ULTIMTEbros 3

98. CONFIANZA

99. Astato XS

100. GAIA Wire

101. Pilot

102. Sion

103. SAMURAI

104. Dissection and Retentry
EQUIPMENTS

105. Crossboss catheter

106. Stingray catheter & guidewire

107. SNARE

108. • “to capture the retrograde guidewire into the antegrade wire”
• Ensnare – 3 loop
• Atrieve – 3 loop
• Amplatz Goozeneck – 1 loop

111. ANCHOR TECHNIQUES

112. X 3
• 1. Sidebranch
• 2. Coaxial
• 3. Distal

113. TECHNIQUES of CTO

114. WIRING
MOST IMPORTANT

115. Walking in the dark with a lamp

116. • Antegrade approach
• Retrograde approach
• Hybrid approach

117. In short !!

118. Preparation
• Make an echo machine available in the lab
• Have a pericardiocentesis set ready
• Tell your cardiology colleagues and have them somewhere around
• Inform your cardiac surgeon and cardiac anesthesiologist

119. Wiring Strategy – Antegrade or Retrograde ?

121. ANTEGRADE WIRING

123. Don’t cause injury !! BEND IT WELL

125. Reach using a soft tipped guidewire

126. Excahnge with a CTO crossing wire

127. A tapered, polymer-jacketed wire (such as the Fielder XT, Fielder XT-A
or Fighter) is usually used first to track a microchannel (which may
sometimes be invisible).s

129. Shaping the guidewire tip
• SMALL DISTAL BEND
• a. Enhances the penetrating capacity of
the guidewire.
• b. Facilitates entry into microchannels.
• c.Reduces the likelihood of deflection
outside the vessel architecture or into
branches arising within the occlusion.
• d. Improves steerability within tight
spaces, such as the CTO segment, which
would normally straighten larger bends.

130. Advancing techniques
• Sliding
• Drilling
• Penetration

131. Wire crossed. But where is it ?
• Contralateral injection – BEST METHOD
• Sudden SPONTANEOUS FREEDONE OF WIRE Tip  TRUE distal lumen
• Exchange with workhorse wire  it moves freely

132. Wire crossed. But where is it ?
• In TRUE Distal Lumen ?  Proceed balloon and stenting
• In Distal subintimal space ?
• 1. Directed penetration – by bringing a microcatheter into subintimal space
and position its TIP adjacent to a well seen segment of TRUE DISTAL LUMEN
• 2. Subintimal crossing and reentry techniques – Crossboss and Stingray
• 3. PARALLEL WIRE TECHNIQUES
• 1. Parallel wire
• 2. See-Sae
• 3. Dual lumen MICROCATHETER

133. Parallel wire

134. See Saw technique

135. Dual lumen Microcatheter

136. ANTEGRADE DISSECTION
and Reentry

137. Classification

138. Subintimal Space !!!
• Typically no intimal layer within the atheroma of a totally occluded artery
• Rather, subintimal in CTO percutaneous coronary intervention (PCI) has
evolved as a general term that refers to a tissue plane within or beyond
the occlusion that may be
• (1) sub-intimal, (2) intraplaque, (3) intraadventitial, or (4) combinations
thereof, where the location of a tissue plane is related to disease
morphology and position along the length of the artery.

139. Antegrade Disseciton strategies
• 1. Wire based – KNUCKLE WIRE (not recommended)
• 2. Catheter based – CROSS BOSS CATHETER (recommended)

140. WIRE BASED - KNUCKLE WIRE
• Push the wire further until it forms a knuckle
• Faster
• Safer
• Less likely to enter branches

141. Limit the diameter of the knuckle, LARGE knuckle enlarges the
subintimal space and hinders RENTRY

142. CATHETER BASED
• Crossboss Catheter
• Stingray if it enters the subintimal space

148. Crossboss torque attachment

149. Fast spin
rotated using the index finger and thumb of both hands
Faster spinning decreases friction and increases the likelihood of advancement and
crossing.

150. Cross boss fails to advance

162. Non-stingray Reentry techniques
• Subintimal tracking and reentry (STAR)
• Limited STAR
• Carilino technique
• Modified Carilino

163. RETROGRADE WIRING

166. RETROGRADE WIRING and
DISSECTION

168. Wiring unsuccessful ?

170. BALLOON

171. Balloon not crossing ?

172. Balloon not dilating ?

173. STENTING

174. • Tired !!!
• If you stent fast – Restenosis/Thrombosis
• OPTIMISE first
• Use IVUS

175. COMPLICATIONS
during CTO Intervention

178. PERFORATION

179. STOP THE PROCEDURE IF
• No wire success in 60 minutes of procedure time or 30 minutes of
fluoro time
• No balloon success in 2 hours of procedure time or 1 hour of fluoro
time
• Dye limit crosses . Usually 400 ml in normal renal function patients

180. FAILED CTO. What Next ??
• Reattempt after 2 – 4 weeks
• Reattempt with retrograde technique after 2 weeks
• Immediate switch to retrograde technique
• Make use of higher expertise

181. Trials on CTO

182. Conclusions – SEVEN Key Principles

183. THANK YOU