Successful Crossing of an Angulated Lesion Using a New Deflectable-Tip Guidewire (Steer-IT‚Ñ¢)

Case Report

A 73-year-old diabetic male with prior CABG (1987) and re-do CABG (1999) presented with 3 months of escalating angina on effort. A thallium scan demonstrated inducible ischemia in the anterior myocardial wall and apex. Diagnostic angiography revealed an occluded left internal mammary artery graft to the LAD with a severe stenosis in the left main bifurcation and LAD arising at an acute angle from the left main (LM) artery (Figure 1A). The left circumflex artery (LCx) was occluded beyond the proximal segment with a patent vein graft maintaining perfusion in this territory.
Using a 6 Fr Extra Back-Up 4.0 Launcher guide (Medtronic), multiple guidewires (Balance Middleweight Universal, Pilot 50, Whisper; Guidant Corp., Indianapolis, Indiana) were used with various primary/secondary curves at the tip, but even if the tip engaged the vessel, gentle pushing with and without rotation did not advance the wire and resulted in immediate prolapse into the LCx. Balloon support was unsuccessful. A Steer-IT deflectable-tip wire was advanced into the LCx immediately distal to the LAD origin and the tip was deflected and steered in the LAD with a combination of gentle pushing and progressive straightening of thedistal curve (Figure 1B). The wire was disconnected from the handle governing tip deflection and used throughout the procedure (predilatation, stent implantation of a 3.5 x 13 mm sirolimus-eluting stent [Cypher Select, Cordis] and postdilatation with a 4.0 mm balloon] (Figure 1C).

Discussion

Prior attempts to develop deflectable-tip guidewires^3,4 have been met with poor steerability and torqueability, thereby precluding a more widespread use. The SteerIT device has recently become available for commercial use in Europe and the United States andincorporates a 0.014 inch nitinol Teflon-coated wire. The distal 7 mm tip of the wire can be manipulated to deflect in 2 planes using a detachable handle containing the actuator (Figure 1D). The tip can be directed to negotiate acute angles and tortuosity while maintaining many of the properties intrinsic to modern interventional guidewires including steerability, trackability and torque control (Figure 1E). Such features may also be advantageous in crossing jailed stent struts in bifurcation lesion interventions.
Other than deflecting tip guidewires, catheter-based systems such as the Venture catheter (St. Jude Medical, Inc., St. Paul, Minnesota) may offer better support to a wire crossing angulated and tortuous vessels, preventing wire prolapse. Such a device also leaves the decision of which guidewire to use up to the operator.^5,6 Flexible over-the-wire catheters can also support the wire, but they are unlikely to track if only the very tip of the wire can be engaged.
Devices that aid in negotiating difficult segments of a patient’s vasculature can improve the chances of a successful outcome. The device used in this report has the advantage of being bidirectional with its novel deflectable tip, while maintaining many of the properties an interventional cardiologist would expect from a guidewire. Such a device is therefore a useful contributor to the armamentarium of the modern interventional cardiologist.

References

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