12th Experts Live CTO The annual Euro CTO meeting September 11th –12th, 2020 - Berlin, Germany

1. CT guided CTO PCI
EURO CTO CLUB
Berlin, September 11/12, 2020
Patrick T. Siegrist, MD
Andreas Grüntzig Heart Catheterization Laboratories
University Hospital Zurich and
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

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.
Operator dependent presets.
Curved MPR

4. The Present Commonly Used
Imaging Methods
Volume Rendering
Time-consuming computation required.
Limited to a superficial observational view.

5. A Recommended MSCT Coronary
Angiography Imaging Method
for Interventional Cardiologists
“Sliding Slab MIP”
method

6. Sliding Slab MIP method

7. 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.

8. MIP; Maximum Intensity
Projection
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.

9.  Move the slab back and forth.
 Rotate the Heart.
 Change the slab thickness.
Only “3 Actions” !!

10. Move the slab back and forth
Find out the
intended coronary
tree.

11.  Move the slab back and forth.
 Rotate the Heart.
 Change the slab thickness.
Only “3 Actions” !!

12. Rotating the Heart
Visualizes any
intended projection
of the coronary tree.

13. Slab MIP image
Visualizes any intended
projection of the coronary
arteries

14.  Move the slab back and forth.
 Rotate the Heart.
 Change the slab thickness.
Only “3 Actions” !!

15. Changing the Slab Thickness
Excludes the extra
enhanced structures
of less interest around
the vasculature.

16. Slab MIP and CAG image

17. Integrated imaging

18. Slab MIP Images of
Normal Coronary Arteries
RCA
(LAO) (CRA)

19. 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

20. Case 1: RCA CTO

21. Case 1: antegrade approach

22. RCA CTO

23. RCA CTO

24. RCA CTO

25. RCA CTO

26. RCA CTO

27. RCA CTO

28. RCA CTO

29. Case 2 How to Predict Subintimal Tracking

30. Case 2: How to Predict Subintimal Tracking

31. 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

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

33. Case 3: Calcium as Landmark

34. Landmark calcification
Case 3: Calcium as Landmark

35. Landmark calcification
Case 3: Calcium as Landmark

36. Case 3: Calcium as Landmark

37. Case 3: Calcium as Landmark

38. Case 3: Calcium as Landmark

39. 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)

40. 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)

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

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

43. Case 4: antegrade success with CT support
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44. Case 4: antegrade success with CT support
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Case 4: antegrade success with CT support

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

47. 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

48. Case 5: Unique collateral channel

49. 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.

50. 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

51. 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.

52. 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

53. Novel Angio-CT (XACT)
Toshiba INFX-8000C/AquilionONE Vision Edition
Treat and verify in the same room – on a single system

54. CT Fusion
Baseline CT scan
(i.c. contrast)
Wire position CT scan
Non-rigid
image registration
Fusion image
radiopaque wire tip
guiding catheter
LAD
LAD

55. Color Coded Cross Sectional Images
-3000 - 0
1 - 50
51 - 250
> 251
Color code CT value (HU)
Low density (e.g. fatty tissue)
Low-intermediate desity (e.g.fatty-fibrous)
Intermediate density (e.g. fibrous)
High density (e.g. contrast, calc, metal)
LAD
CT gray scale
Cross sectional view
(gray scale)
Cross sectional view
(color coded)
Fusion image
cross section superimposed wire

56. Case example 1: Subintima (RCA CTO)
Initial Angiogram Antegrade Wiring
The wire could be advanced into the
CTO, however the course of the RCA
was unclear.
The RCA was occluded from the mid
segment (J-CTO score: 3).
Ipsilateral collateral channel

57. Case example 1: Subintima (RCA CTO)
CT Fusion
①
①
②
②
③
③
④
④
⑤
⑤
⑥ ⑥
The CT revealed, that the wire runs in the center of the vessel up to position ①.
After that the wire migrates off the center (position ②) and circles the vessel
border clockwise (position ③ー⑥); i.e. a sign of subintimal tracking.
Cross Section

58. 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
• … helps to find landmarks
• … helps to predict subintimal tracking
• … helps to find the best view/projection

59. Thank you
Patrick T. Siegrist, MD
Attending Physician / Interventional Cardiologist
Andreas Grüntzig Catheterization Laboratories
University Hospital Zurich
and
HerzZenztrum Hirslanden Zurich
Email: patrick.siegrist@usz.ch