This document proposes teaching chronic total occlusion (CTO) percutaneous coronary intervention (PCI) as a modular system to improve learning. It identifies several CTO techniques that could each be considered a module, such as collateral passage, subintimal techniques, parallel wires, and reverse controlled antegrade and retrograde tracking (CART). The document hypothesizes that breaking down CTO PCI teaching into these individual modules would make the techniques and components easier to understand compared to observing complex full cases. It then provides a detailed example of how the reverse CART technique could be taught as its own module. In conclusion, teaching CTO PCI in modular form may facilitate learning techniques, and modules are suitable for both conference presentations and online learning.

1. Teaching CTO
as a Modular System
Achim Büttner
EUROCTOCLUB Krakow, 30. September / 1. October 2016
Germany

2. No disclosures to declare

3. Why is CTO PCI fun?
• Technically challenging
• Contemporary recanalisation techniques allow for success
rates >90%
• Choice of different modules / techniques / materials
at certain points of the intervention
• Room for individualisation and technical refinement

4. Why is CTO PCI difficult to learn?
• Largely standardised recanalisation techniques are developed
from „consolidated knowledge“
• There is limited detailled information on appropriate techniques
from the literature
• During CTO conferences beginners are confronted with:
- a hughe CTO glossary
- complex interventions with many technical components
- application of tools beyond any reimbursement

5. Teaching that concentrates on CTO modules
would improve learning and getting familiar with
techniques
Hypothesis

6. Module = one of a set of parts
that can be connected or combined
to build or complete something
www.merriam-webster.com/dictionary

7. Collateral
passage
Subintimal
technique
Parallel
wires
Wire
escalation
Antegrade RetrogradeConnection
Retrograde
CTO wiring
Side-branch
technique
Subintimal
technique
Tip-in
Marker
wires
Reverse
CART
Externalisation

8. Reverse CART: Balloon dilatation from antegrade
Modified from M. Ochiai
Retrograde wire enters
after balloon deflation

9. Module: Reverse CART
• Localisation: - Relatively straight CTO segment mid vessel
- also possible more proximal or distal
- may be repeated at different levels
- not at ostium or bifurcation
• Close proximity of antegrade and retrograde wires in
estimated vessel course
• Sufficient wire overlap (> 1cm)
• Balloon from antegrade: 2.0 – 2.5mm / 15 – 20mm
(eventually pre-dilatation with smaller balloon)

11. Reverse CART: Retrograde wires
Wire from retrograde has to penetrate tissue..
Steerability
through microcatheter
Penetration
force
Intermediate non-tapered (Ulimate 3g) +++ +
Intermediate tapered (Gaia 2nd, 3rd) +++ ++
Hard tapered (ConfianzaPro12/Progress200T) + +++
Hard polymeric (Pilot 200)* ++ ++(+)
*useful in subintimal position

12. Reverse CART
From antegrade:
2.5mm balloon
Retrograde wire subintimal:
Pilot 200

13. Reverse CART: Retrograde passage towards antegrade guide
Modified from M. Ochiai
1. Retrograde wire has entered
lumen after balloon deflation
2. Then microcatheter follows
3. Additional proximal balloon
dilatations to facilitate wire
passage from retrograde

14. Reverse CART: Retrograde wire entry into antegrade guide
• If wire entry into antegrade guide is difficult:
- exchange to standard wire with bigger tip curve
- manipulate guide to coaxial position or different heights at ostium
• Follow with retrograde microcatheter (if microcatheter gets stuck →
wire trapping manoeuver or rendez-vous in antegrade guide)

15. Reverse CART: Additional devices
• IVUS for unclear antegrade / retrograde wire course (€/$)
• Retrograde wire enters at ostium into ascending aorta:
→ snaring manoeuver (€/$) after exchange of retrograde
wire to RG3
• Guiding catheter extension (e.g. Guideliner) to facilitate
retrograde wire entry into antegrade guide (€/$)
Eventually necessary or helpful…

16. Collateral
passage
Subintimal
technique
Parallel
wires
Wire
escalation
Antegrade RetrogradeConnection
Retrograde
CTO wiring
Side-branch
technique
Subintimal
technique
Tip-in
Marker
wires
Reverse
CART
Externalisation

17. Exchange to long wire (RG3 330cm)
and externalisation

18. Collateral
passage
Subintimal
technique
Parallel
wires
Wire
escalation
Antegrade RetrogradeConnection
Retrograde
CTO wiring
Side-branch
technique
Subintimal
technique
Tip-in
Marker
wires
Reverse
CART
Externalisation

19. „Tip-in“ manoeuvre in guiding catheter
Retrograde microcatheter
in antegrade guide
Antegrade wire
Meeting point in outer guide curve

21. Limitations
• Definition of modules
• Agreement on recommendations in an expert panel
• Continous improvements in material and techniques
• Price versus advantage of tools difficult to define;
dependent on situations and alternatives
• Practical training of a certain module that is only part of a
CTO intervention (simulator training?)

22. Conclusions
• Teaching CTO as a modular system might faciltate learning
of CTO techniques
• A break down on CTO modules during CTO conferences
(e.g. ten minutes for „Reverse CART“) could parallel the
typical presentation of „crazy“ cases
• CTO modules are appropriate for internet based learning
(e.g. on homepage of the EuroCTO Club)