CTO Flashcards
What is the principle indication for CTO PCI?
Improve angina and quality of life
What is the TIMI score of CTO?
0 with a duration of at least 3 months
CTO PCI can improve? (3)
Capacity to exercise
Increase anaerobic threshold
Alleviate depression
What are the risks of CTO PCI? (6)
-Acute MI
-Perforation
-CABG emergency
-Death
-Restenosis
-Stent Thrombosis
CTO should be considered in patients with what? (2)
Angina resistant to medical therapy or large areas of ischemia of the occluded vessel
What should be used and is critical for the success and safety of CTO PCI? (2)
Dual Angiography unless collateral circulation is originating from the CTO vessel
How do you do dual angiography for CTO that the collaterals are not originating from the CTO vessel? (3)
-Donor vessel is injected first
-Followed by injection of the CTO vessel 2 to 3 seconds later with lower magnification
-Avoid panning to result degradation of image quality
What are the four main anatomy focuses of CTO angiography?
-Proximal cap morphology
-Occlusion length, course, and composition (eg calcium)
-Quality of distal vessel
-Collateral circulation
What are some CTO strategies to find the proximal cap and its type? (4)
-Dual injection
-Selective contrast injection through a microcatheter
-intravscular ultrasound (IVUS)
-Real time CCTA
If the location of the proximal cap remains unclear, what should be done? (3)
A retrograde approach
Move the cap dissection
Reentry techniques
What can lead to overestimation of the lesion length due to under filling and poor opacification of the distal vessel?
Antegrade only injections
What guide wire is preferred when the vessel course is unclear or highly tortuous due to low risk of perforation?
Knuckled J tipped wire
How should determining the feasibility of retrograde approach with high quality dual angiography be done?
Obtained during breath hold and no panning
Retrograde crossings can be attempted by going through?
Collaterals or Bypass grafts
The size of the collaterals is often assessed using what classification? (4)
Werner:
CC0: No continuous connection
CC1: Threadlike connection
CC2: Side branch like connection
What technique is used to cross invisible septal collaterals?
Surfing technique (advancement of the guide wire with simultaneous rotation
Why should previous angiograms be reviewed for potential collateral pathways because of change before or during the procedure?
Shifting collaterals
What helps selective contrast tip injections that can help collateral anatomy?
Microcatheter
Why are aorotcoronary bypass grafts favorable retrograde conduits? (3)
Absence of side branches
Predictable course
Large caliber
Why are septal collaterals preferred over epicardial collaterals?
Lower risk of perforation that can cause tamponade.
What wire is typically safe and easier to navigate through septal collaterals?
Soft tip polymer jacketed guidewires
What can be used to safely dilate septal collaterals to facilitate microcatheter or device crossings?
Small balloons
What is the oldest and most commonly used score for CTOs?
J-CTO
What does J-CTO score developed to estimate?
Likelihood to successfully cross antegrade guidewire within 30 minutes based on 5 criteria
What are the 5 criteria for J-CTO
1: At least 1 bend of >45 degrees in CTO entry or body
2: Occlusion length > 20 mm
3: Calcification
4: blunt proximal stump
5: Previously failed attempt.
What are some other CTO scores? (4)
PROGRESS
RECHARGE
CASTLECT-RECTOR
CTO CT
What is used to assess the risk of CTO PCI?
Progress CTO complications score
What are the 3 variables in Progress CTO complications Score?
-Length >23 mm
-Use of Retrograde approach
-age > 65 years old
Why do you want to use micro catheters routinely for CTO crossings? (3)
Supporting guide wire
Facilitating guide wire exchanges
Tip reshaping
Micro catheters can help cross what and protect from what?
-Retrograde collateral channels
-Wire induced trauma
What are the four CTO crossing techniques?
-Antegrade wiring
-Antegrade dissection and re entry
-Retrograde wiring
-Retrograde dissection and re entry
What can help determine guide wire position during crossing attempts?
Contralateral injections
Orthogonal Angiographic Projections
When the guidewire enters the true distal lumen, what should be done next? (2)
-Microcatheter is advanced into the distal true lumen
-CTO guide wire is exchanged for a workhorse guide wire to minimize risk of distal vessel injury
Why should subintimal guide wires not be advanced to the distal cap?
To prevent hematoma formation that can cause luminal compression and hinder guide wire crossing
How does the STAR technique work (Subintimal Tracking and Reentry)
Uses non targeted reentry into the distal lumen by pushing a knuckled wire distally through the occluded segment until it reenters the true lumen distally
What does the STAR technique often assiociate with? (2)
High rates of in stent restenosis
Reocclusion
What is the STAR technique currently only used for?
Bailout without stent implantation for preparation of a repeat CTO attempt.
What is the most commonly used retrograde crossing technique?
Reverse controlled antegrade and retrograd tracking (reverse CART)
How does reverse CART work for retrograde approach?
The ballon is inflated over the antegrade guidewire
Followed by retrograde guide wire advancement through the space from the ballooon
When should you stop CTO PCI? (5)
-High radiation dose (>5 gray air kerma dose)
-Complications
-High contrast volume
-Exhaustion of crossing options
-Fatigue of patient or doctor
What should CTO lesions be before stent implantation?
Fully expanded and pre dilated with balloons/artherectomy.
What is the average risk of complications?
3%
To facilitate risk of donor vessel thrombosis, the goal for ACT is? (2)
-300 for antegrade cases
350 for retrograde cases
