Why Ikari Left is Preferred Over Ikari Right for RCA Intervention
The Ikari left catheter is preferred over Ikari right for RCA intervention because it provides superior backup support by utilizing the reverse side of the aorta as its primary attachment site, which generates stronger mechanical force compared to the Ikari right's attachment at the brachiocephalic artery. 1
Mechanism of Superior Backup Support
Primary Attachment Site Differences
The Ikari left catheter achieves its "power position" by engaging the reverse side (contralateral wall) of the aorta as its primary attachment site, which is fundamentally different from other catheter designs. 2
This contralateral aortic wall engagement occurs both in transfemoral and transradial approaches, providing consistent mechanical advantage regardless of access site. 2
In contrast, the Ikari right catheter's primary attachment site is the brachiocephalic artery in transradial intervention, which generates less backup force. 2
Mechanical Advantage in Complex Anatomy
For RCA interventions requiring increased backup support—particularly in patients with dilated aortic roots or anterior/"shepherd's crook" RCA origins—the Ikari left (3.5 or 4.0) is specifically recommended by the American Heart Association as a preferred guide catheter shape. 1
The Ikari left's unique three-dimensional curve compensates for unfavorable angles between the innominate artery and proximal RCA, achieving coaxial engagement with strong support. 3
When slight backward motion occurs during device advancement (a common occurrence during stent delivery), the Ikari left maintains its attachment at the reverse aortic wall, preserving backup force. 2
Clinical Performance Data
Single-Catheter Versatility
The Ikari left 3.5 can successfully engage both right and left coronary arteries, achieving device success (good backup at both coronaries) in 96.6% of cases, making it highly effective as a single transradial guiding catheter. 4
In a prospective study of 621 patients, the Ikari left achieved 98.2% procedure success for both diagnostic and interventional cases, with only 0.48% catheter-induced RCA dissection rate. 4
The Ikari left's design allows it to function as a dedicated TRA catheter that can engage either coronary ostium with options for passive or active support depending on engagement technique. 1
Comparison to Standard Approaches
The Ikari left demonstrates equal or superior performance compared to transfemoral approaches, with fluoroscopy times of 14.5±9.5 minutes and contrast volumes of 153±53 ml in transradial intervention. 5
Standard Judkins right catheters frequently provide insufficient support for RCA intervention, accounting for 7-17% of TRA PCI failures due to inadequate backup. 1
Practical Application
When to Choose Ikari Left
Immediately select Ikari left when encountering dilated aortic root, anterior RCA takeoff, or shepherd's crook anatomy rather than persisting with inadequate Judkins right support. 1, 6
For time-sensitive primary PCI in STEMI, consider becoming familiar with Ikari left as part of a single-guide catheter technique to avoid catheter exchanges. 1
The Ikari left is particularly valuable when coaxial engagement is critical—positioning the RCA catheter anterior to the left main catheter improves coaxiality (median angle 27.0° vs 53.7°). 7
Technical Considerations
Most interventions can be performed with 6F Ikari left catheters; for larger equipment needs, sheathless guide techniques or thin-walled 7-in-6F sheaths may be used. 1, 6
Exchange-length wires should be used for all catheter exchanges once safely seated in the ascending aorta, particularly with significant subclavian tortuosity. 1, 6
Common Pitfalls to Avoid
Persisting with Judkins right when inadequate support is evident leads to prolonged procedure time and increased complication risk—early recognition and switching to Ikari left prevents this. 6
Forceful attempts to engage difficult RCA ostium with inadequate catheter shape increases dissection risk; gentle technique with appropriate Ikari left selection is safer. 6
The primary failure mode for Ikari catheters is tortuous brachiocephalic arteries (accounting for all failures in one series), which can be addressed with balloon-assisted or catheter-assisted tracking techniques. 1, 5