1. Patrick T. Siegrist, MD
Interventional Cardiologist
HerzZentrum Hirslanden
Switzerland
in close collaboration with
Satoru Sumitsuji, MD, FACC
Department of Cardiology for International
Education and Research
Osaka University Graduate School of Medicine
Japan
CT guidance for CTO Revascularization
EURO CTO CLUB
Florence, September 17/18, 2020

2. Concept of Imaging Guided PCI
Complex/CTO PCI
Planning → CT
Procedure → IVUS
NOT CALIBRATED

3. Commonly used imaging methods
Unfamiliar image for interventional cardiologists.
Curved MPR

4. “Sliding Slab MIP” Method
Recommended MSCT imaging method
for interventional cardiologists

5. Definition of “slab”

6. Slab MIP image
Maximum Intensity Projection (MIP) is a volume rendering technique which is used to visualize
high-intensity structures within a volumetric data. At each pixel, the highest data value, which is
encountered along a corresponding viewing ray is depicted.

7. Slab Thickness
Maximum intensity projection (MIP) is a method for 3D data that projects in the visualization plane the voxels
with maximum intensity that fall in the way of parallel rays traced from the viewpoint to the plane of projection.
MIP: Maximum Intensity Projection

8. Angiogram
MIP
Ptifall in MIP Imaging: Eccentric Lesion

9. • Move slab back and forth
• Rotate heart
• Change slab thickness
Only 3 actions:
Simple Navigation

10. 1st Action: Move Slab Back and Forth

11. • Move slab back and forth
• Rotate heart
• Change slab thickness
Only 3 actions:
Simple Navigation

12. 2nd Action: Rotate Heart

13. • Move slab back and forth
• Rotate heart
• Change slab thickness
Only 3 actions:
Simple Navigation

14. 3rd Action: Change Slab Thickness

15. Slab MIP and CAG image

16. Integrated imaging

17. Slab MIP Images of Normal Coronary Arteries
LAO CRA
RCA

18. RAO 50
CAU 10
RAO 51.2
CAU 11.8
RAO 40
A B C
Siegrist PT, Sumitsuji S. Cardiovascular Medicine 2014;17(12):347-56
Determine optimal projection

19. Case 1: RCA CTO

20. Case 1: antegrade approach

21. RCA CTO

22. RCA CTO

23. RCA CTO

24. RCA CTO

25. RCA CTO

26. RCA CTO

27. RCA CTO

28. Case 2 How to Predict Subintimal Tracking

29. Case 2: How to Predict Subintimal Tracking

30. Case 2: How to Predict Subintimal Tracking
3.0mm
Sigmoid shape can be a sign of subintimal
tracking.
Compare the width of the “S” to the vessel size.
3.0mm
3.0mm

31. RAO CRA LAO CRA
Case 3: Calcium as Landmark

32. Case 3: Calcium as Landmark

33. Landmark calcification
Case 3: Calcium as Landmark

34. Landmark calcification
Case 3: Calcium as Landmark

35. Case 3: Calcium as Landmark

36. Case 3: Calcium as Landmark

37. Case 3: Calcium as Landmark

38. Plaque characterization on CT –
Cross Sectional View
(Color mapping)
-1000-0
1-50
51-250
251-350
700-2000
Thin slice,
cross-sectional view
CT value (HU)

39. Assessment of Calcified Plaques by MSCT
bean stone rock
C-type ring
multi
full moon
Predictive of PCI
procedural difficulty
(provided by Yamasaki K MD;
Osaka University)

40. Classification of calcium
Center/Full Moon
Difficult
Partial
Depends on size
Outside
Depends on thickness
PCI

41. Classification of calcium
Partial
Depends on size
Outside
Depends on thickness
Center/Full Moon
Difficult
PCI

42. Live Case 5 EuroCTO Club 2020
Gerald Werner, Youssef Abdelwahed

43. Live Case 5 EuroCTO Club 2020
Gerald Werner, Youssef Abdelwahed

44. Case 4: antegrade success with CT support
NOT CALIBRATED

45. Case 4: antegrade success with CT support
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Case 4: antegrade success with CT support

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Case 4: antegrade success with CT support

48. The RCA was occluded from the mid segment (J-CTO score: 3)
Unique collateral channel: originating from sinus node artery, running along the
left atrium, descending to the AV-groove and then connecting to
the distal RCA.
Case 5: channel visualization

49. Case 5: Unique collateral channel

50. Case 5: Unique collateral channel
Unique collateral channel: originating from sinus node artery, running along the
left atrium, descending to the AV-groove and then connecting to the distal RCA.

51. Case 5: Antegrade approach
An antegrade approach using wires
with increasing stiffness failed.
Rotational fluoroscopy showed an
unnatural course of the wire. The
course of the RCA remained unclear

52. Case 5: Retrograde approach – channel negotiation
After a Finecross microcatheter was not able to follow the tortuous channel it
was exchanged to the new Caravel. Finally a SUOH guidewire followed by the
Caravel microcatheter could cross the channel and reach the distal CTO entry
point at the RCA bifurcation.

53. Case 5: Final angiogram
Final angiogram displayed successful revascularization of the right coronary
artery and no significant vascular complications.
Procedure time: 3 hrs 50 min, Contrast: 260 ml
Fluoro time: 102 min, Air kerma: 4164.57 mGy, DAP: 32.9 mGy.m2

55. J-CTO Score: Predict complexity (successful guidewire crossing within 30’)

56. J-CTO score
• Predicts quick guidewire crossing
- Nombela-Franco L et al. Circ Cardiovasc Interv 2013;6:635-43
• Predicts the need for advanced crossing techniques
- Wilson WM et al. Heart 2016;102:1486-93
- Christopoulos G et al. Circ Cardiovasc Interv 2015;8:e002171
• Predicts mid- and long-term outcomes
- Tanaka H et al. EuroIntervention 2016;11:981-8
- Galassi AR et al. JACC 2015;65:2388-400
• Ability to predict technical/procedural success was not consistent
- Galassi AR et al. JACC Cardiovasc Interv 2016;9:911-22
- Wilson WM et al. Heart 2016;102:1486-93
- Nombela-Franco L et al. Circ Cardiovasc Interv 2013;6:635-43

57. J-CTO Score by CT
Fujino A et al. JACC Cardiovasc Imaging 2018;11:209-217

58. Comparison CT-derived vs Angio-derived J-CTO Score
Fujino A et al. JACC Cardiovasc Imaging 2018;11:209-217

59. Predicting Performance (ROC)
Fujino A et al. JACC Cardiovasc Imaging 2018;11:209-217

60. Conclusions
CT is an ideal tool for preparation of CTO PCI because it…
• … shows the entire course of occluded vessel
• … provides information on plaque characteristics/calcification pattern
• … helps to find landmarks
• … helps to predict subintimal tracking
• … helps to find the best view/projection
• … predicts complexity

61. Thank you
Patrick T. Siegrist, MD
Interventional Cardiologist
HerzZenztrum Hirslanden Zurich
Switzerland
Email: siegrist@herzzentrum.ch