January 29, 2015

RXi Communication Summary

Topic / “Maintaining wire position while measuring FFR
in a patient with difficult-to-cross lesions”
RXi Case Study Series, No. 3
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Description / RXi case studyNo. 3 has been provided by Prof Dr. med Thomas Münzel and Dr. med Eberhard Schulz, University Hospital Mainz, Germany. This case highlights the benefits our catheter-based FFR technology provides when obtaining FFR measurements in a diffusely diseased circumflex artery with ISR (in-stent restenosis).
Key Takeaways / The 90-degree take-off made it difficult to advance the PCI wire (HI-TORQUE® Balance Middleweight Elite). The PCI wire was not able to cross the ISR. In order to maintain wire position, a FineCross™ catheter was advanced and the PCI wire exchanged for a Cross-it 100XT wire. This wire crossed the ISR and was advanced beyond the lesion. The FineCross catheter was then removed. The Navvus® Rapid Exchange MicroCatheter was introduced, equalized and advanced beyond all of the lesions.

  • WHAT TO SAY: RXi’s rapid exchange technologywas able to take advantage of utilizing the already positioned Cross-it 100XT wire to advance the Navvus MicroCatheterbeyond all of the lesions in this challenging, diffusely diseased circumflex anatomy. It is unlikely a pressure wire would have been able to advance across these lesions and most likely not with the efficiency experienced when using the Navvus MicroCatheter.
The pre-intervention FFR measurement was 0.78 after IV adenosine was administered. Implantation of a new-generation Absorb™ stent was attempted, but the stent did not cross the mid-circumflex lesion. Two 2.75 X 15.00mm Xience stents were implanted, one in the distal ISR and the other in the mid-circumflex lesion. A pull-back measurement was performed to confirm whether the proximal lesion was clinically significant. The FFR measurement was found to be near normal when the sensor approached the proximal lesion.
  • WHAT TO SAY: Maintaining guide wire position made it easy to do a pull-back assessment and measure FFR post-intervention. This was important to the clinician as it helped determine that the proximal lesion was not clinically significant.
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Conclusions / Both physicians involved in this case believed it would not have been productive to attempt to use a pressure wire in this anatomy. The RXi rapid exchange technology may allow clinicians to expand FFR utilization in more complex and challenging anatomies.
Order Info / Titled: Mainz Case Study, No. 3