Chief Medical Editor's Page
Treatment of Total Occlusions
ATreatment of chronic total occlusions remains one of the more vexing problems for coronary and peripheral vascular interventionists. It has been said that one third of all patients undergoing diagnostic cardiac catheterization are found to have total occlusion of one of their coronary arteries. Approximately 10% to 20% of all percutaneous coronary interventions are for total occlusions. In the peripheral circulation, total occlusions are also quite common. Total occlusion of the superficial femoral artery is present in up to 50% of patients presenting with symptoms of peripheral arterial occlusive disease. For the patient with critical limb ischemia, multilevel disease with occlusion of some or all of the tibial arteries is characteristic.
Traditionally, successful passage of a guidewire through the occlusion was the major determinant of acute procedural success. For that reason, a number of specialty guidewires were developed to try and optimize the chances of crossing success. Vibrating guidewires, laser guidewires, guidewires with special tips, hydrophilic guidewires, and enhanced-force guidewires have all been evaluated with varying degrees of success. Even when the occlusion could be crossed and procedural success achieved, high rates of restenosis and/or reocclusion have discouraged operators from treating CTOs. CTOs in the coronary arteries or long peripheral arterial occlusions have been a common indication for referral of patients for bypass surgery. Now, with the improved results seen with new stent designs and drug-eluting stents, there is renewed interest in treating CTOs.
In this issue of Endovascular Today, we will review some of the exciting new modalities for treating CTOs. Matt Selmon, MD, will describe the concept of controlled blunt microdissection and provide an overview of the experience to date with the LuMend Frontrunner Catheter. Mark Wholey, MD, will review the results with the Intraluminal Therapeutics Safe-Cross Radiofrequency Total Occlusion Crossing System. The Safe-Cross system couples the enhanced diagnostic capability provided by Optical Coherence Reflectometry (OCR) with RF energy to facilitate guidewire passage through difficult occlusions. OCR provides the capability to differentiate plaque from vessel wall and thereby increase one’s chances of remaining intraluminal during guidewire passage through the occlusion. If one should get subintimal, there are new ways to re-enter the true lumen of the artery and salvage what would otherwise be an unsuccessful procedure. The CrossPoint TransAccess Catheter combines intravascular ultrasound imaging and steerable catheter technology to provide such capability. Jim Joye, DO, will review the potential applications of this innovative technology.
There has been a resurgence of interest in laser technology for the treatment of peripheral arterial occlusive disease, particularly for the treatment of long occlusions and complex multilevel disease. Tony Das, MD, will provide his perspective on the potential advantages of excimer laser angioplasty for the treatment of CTOs. Results will also be presented from the recently completed LACI (Laser Angioplasty for Critical Limb Ischemia) trial.
I think this issue will convince you that progress is being made in the battle against CTOs. In the future, even more patients will have the opportunity for a less invasive treatment for their arterial disease.