The excellent case reports in this issue of CLD demonstrate the use of deep intubation using the GuideLiner guide extension system (Teleflex) to facilitate complex coronary intervention in the mid and distal right coronary artery (RCA). Indeed, most interventional cardiologists, and especially those who engage in complex, higher-risk, and indicated PCI (CHIP), understand the power of guide extension to facilitate stent delivery through tortuous vessels. Guide extension has become a workhorse device for coronary intervention, because of its ability to facilitate device delivery. Current data suggests that approximately 18% of percutaneous coronary interventions (PCIs) are now done with guide extension (Fischell et al, unpublished data, July 2020). This has become even more crucial as we move to radial interventions, with less guiding catheter backup support. In most cases, the guide extension is used to provide additional backup by advancing the tip of the blunt-ended tubular guide extension system into the proximal to mid portion of a coronary artery, but usually not distally.
Although most operators appreciate the power of deep intubation in complex cases, performing deep intubation with the current guide extension systems can be technically challenging or not possible, and potentially dangerous. Even when one delivers the guide extension over the shaft of a balloon catheter or stent delivery system, the blunt-edged tubular structure (Figure 1) can catch on fibrous lesions, calcium, or stent struts, lift up plaque, embolize material, or cause coronary dissection. The inability to deliver the guide extension catheter distally enough results in failure of guide extension in ~20% of cases.1 Coronary dissection has been reported in ~3% of cases, even without deep intubation.1
Delivering the GuideLiner, Guidezilla (Boston Scientific), or other current guide extension devices distally often requires continued manipulation with balloon inflations to anchor or balloon inflations at the distal end of the guide extension in order to “inchworm” slowly, millimeter by millimeter, down the coronary artery. The current case reports demonstrate the successful use of these techniques to deliver the GuideLiner to the mid or distal RCA.
There is newer technology on the horizon that may facilitate distal delivery of guide extension systems. A next-generation guide extension system called the CrossLiner features a flexible, low profile, monorail, inner microcatheter that facilitates a seamless (no edge) transition as one moves the guide extension structure down a tortuous coronary artery. After delivery to a distal target site, the monorail inner catheter is removed and a balloon catheter or stent delivery catheter is then delivered to the target lesion. Images of this new device are shown in panels B and C of Figure 1. It is expected that this device may be available commercially in the early part of 2021. Once the CrossLiner becomes available, it is possible that atraumatic “deep intubation” to facilitate device delivery can be accomplished more easily, and importantly, more safely, in the future.
Disclosure: Dr. Fischell is a founder, shareholder, and the CEO of CrossLiner, Inc.
Dr. Fischell can be contacted at firstname.lastname@example.org.
- Waterbury TM, Sorajja P, Bell MR, et al. Experience and complications associated with use of guide extension catheters in percutaneous coronary intervention. Catheter Cardiovasc Interv. 2016;88(7):1057-1065.