From Challenge to Mastery: Managing Difficult Scenarios in CTO
Dr. Mihajlo Kovačić
Head of the Interventional Cardiology and Internal Medicine Departments at the County Hospital Čakovec, Croatia

Basic Information/Patient History
Gender: Male
Age: 64 years old
Past Medical History: Hypertension,Dyslipidemia,Peripheral Vascular Disease,Smoker
Cardiac History: 2014:Underwent PCI of the mid RCA due to stable angina pectoris.
2024:Coronary Angiography confirmed CTO of the RCA (in-stent and proximal segment). Attempted Antegrade Recanalization of the RCA CTO was unsuccessful.
Laboratory Results:
Complete Blood Count: Normal
Renal Function: Normal
Case challenges
Complex Septal Collateral Crossing
MC Switch strategy
Challenging Antegrade Guide Engagement & Ambiguous Proximal Cap
Highly Restricted R-CART at Proximal RCA Curve (Near Old Stent)
Wire Trapping & Externalization
Benign Aortic Cusp Hematoma (Retrograde Extraplaque Origin)
Techniques Used
Anterograde and retrograde wiring
Complex septal collaterals selective crossing with Suoh03 wire
S-BASE
R-CART Guide extension facilitated
Externalization
WALPO technique was used to protect ostium of the RCA, and to define precise ostial stent placement
Procedure Process
Angiography Results
A 0.014” Sion Blue guidewire was delivered to the distal LAD as protection wires and another Sion Blue wire into conus branch of the RCA as protective wire, and after for S-BASE maneuver RCA. Dual contrast injection cine was made in several projections.
LAD: diffuse disease, with 50% stenosis at the mid to distal level,TIMI 3.
LCX: without significant stenosis, TIMI 3.
RCA: CTO of the proximal, almost ostial level, ambiguous cap, TIMI 0%
a)Ambiguous cap with side branches, conus branch
b)P-RCA CTO
c)Old stent with ISR in the beginning of the mid RCA
Treatment Strategy:
Septal Collateral Crossing in retrograde
In PCI
Complex Septal Collateral Crossing
The extremely tortuous septal collaterals with 180-degree bends required careful navigation using a Suoh03 wire and Turnpike LP 150 microcatheter, but crossing was hindered by severe resistance.
Hard Microcatheter Passage & Switch
Due to friction in the tortuous bends, the Turnpike LP 150 could not advance further, necessitating a switch to the TrueCross 1.9 microcatheter, which successfully traversed the collateral and reached the distal CTO cap.
Collateral Visualization & Retrograde Puncture
Selective contrast injection revealed multiple small side branches distally.
Failed retrograde puncture with GladiusEX; antegrade Gaia3 also failed initially.
Repeated attempts: S-Base 1.5mm balloon facilitated Gaia3 wire advancement.
Retrograde-Antegrade Connection (R-CART Technique)
Limited R-CART performed at the stent’s proximal bend using Seigla Liquid 7F GEC.
Retrograde Gaia Next3 wire connected after multiple attempts.
Gaia Next3 trapped to propagate TrueCross Pro into the Liquid GEC system.
Final Steps
RG3 wire externalization completed.
Ballooning
IVUS
WALPO technique (wire in aorta for localization and protection of the ostium) guided precise stent placement.
DCB for in stent restenosis part
Complication management:
Hematoma from retrograde wiring was compressed toward the aortic root by stent deployment (1st attempt).
Second stent (Bioadaptor Dynamix) + DCB deployed for in-stent restenosis (ISR).
Final result with 2x Bioadaptor Dynamix and 1x DCB with benign aortic cusp retrograde hematoma
Post PCI
No procedural or postprocedural complications.
Patient was released 2 days after the procedure.
Key Learnings
This case highlights:
1. How to cross septal complex collaterals with precise movement of the Suoh03 wire. Detailed knowledge about structure of the devices is needed.
2. How to cross septal collaterals with microcatheter, how to rotate each device. What to do when microcatheter doesn’t cross collaterals. How to trap and replace microcatheters. What options of microcatheters do we have.
3. How to solve proximal cap ambiguity – with retrograde wire, /wire knuckle.
4. Hot to do S-BASE (one of the “move the cap” technique)
5. How to do contemporary Guide extension assisted R-CART
6. How to do externalization technique.
7. How to treat in stent restenosis, and diffuse disease.
8. Usage of Bioadaptor stents



