Contributions to the art and technique of chronic total occlusion percutaneous coronary intervention (CTO-PCI) have been growing at an astounding rate in the last 10 years. CTO-specific wires, the parallel-wire technique, IVUS-guided side-branch access, subintimal tracking and the re-entry technique (STAR),1-4 microchannel technique and limited antegrade subadventitial tracking (LAST) (personal communication, Craig Thompson) have all been introduced and proven to be useful antegrade strategies for opening CTOs. Despite these techniques, at least 20% of CTOs require more advanced retrograde techniques, as first suggested by Hartzler5 and later championed by Japanese operators.6 The use of retrograde PCI for recanalization of CTOs is gaining acceptance as a necessary technique to improve success rates. The procedure involves five key steps: 1) wiring of the collateral from the donor artery into the distal bed of the recipient artery, usually with the use of hydrophilic jacketed guidewires; 2) delivery of over-the-wire microcatheters or balloons to allow an exchange for a CTO-specific guidewire; 3) crossing the total occlusion with the CTO guidewire and dilating the CTO with the retrograde balloon; 4) placing an antegrade guidewire into the distal bed through the recanalized CTO; and 5) stenting the lesion. In this issue of the Journal, Wu et al7 describe another modification of the retrograde techniques8 that may further improve success rates by facilitating wire crossing of CTOs. This technique, referred to as confluent ballooning, can be executed after both the retrograde and antegrade wire fail to cross the CTO. Both wires are parked in the subintimal space, and simultaneous inflation of antegrade and retrograde balloons is performed to facilitate enlargement of the subintimal space so that a continuous channel between each side is created. The confluent ballooning technique essentially equates to simultaneous controlled antegrade and retrograde subintimal tracking (CART) and reverse CART maneuvers. Whether this modification of the retrograde technique results in better procedural success, shorter procedure times or better procedural safety remains to be seen. At the very least, this technique represents another example of the continuing expression of creativity and ingenuity possessed by a very select group of CTO-specific operators whose commitment to advancing the case for and improving success rates of CTO-PCI is gaining momentum. Despite these advances, two disparities in CTO-PCI practice patterns suggest that continued technical advances in and education about these advances are desperately needed. First, CTO-PCI attempt rates between low- and high-volume operators are vastly different (10% vs. 18%).9 Second, success rates among dedicated CTO operators have reached 90%, while the general population of operators reflected in the National Cardiovascular Disease Registry (NCDR) achieve success rates of only 70%. Hopefully, continued technical advances like the one described by Wu et al will translate into greater procedural success and/or shortened procedure times and result in better access to revascularization therapy for patients with CTO. With the ability of many operators to now achieve a > 90% success rate with use of the myriad of recently developed techniques, the interventional community will be left with the difficult task of increasing the adoption of this necessary but challenging procedure. It is difficult to train interventional fellows with limited wire skills, angiographic skills and clinical experience to be expert in this complex procedure at such an early stage of their career. For this procedure to gain wider adoption in the United States and elsewhere, it will require dedicated interventional operators willing to invest the time and effort required to cultivate the skill set coupled with longitudinal educational programs with proctors and mentors who can assist with “hands-on” experience in a controlled setting. Lastly, CTO education requires persistence, patience and practice for an interventionalist to escalate the learning curve of approximately 200–300 CTO-PCI procedures, and the numerous failures along the way, to achieve a high success rate despite anatomic challenges. Given the benefit of this procedure on quality of life, left ventricular function and potentially on long-term survival, more operators should develop this unique skill set to improve patient outcomes and ensure complete revascularization. Only by doing this will the coronary interventionalist be able to truly compete with coronary artery bypass graft surgery and improve outcomes in patients with stable coronary artery disease.
From North Cascade Cardiology and St. Joseph Hospital, Bellingham, Washington.
Disclosure: The author has received speaker honoraria from Medtronic and is a paid consultant to Medtronic, Abbott Vascular, and Bridgeport Medical.
Address for correspondence: William L. Lombardi, MD, FACC, FSCAI, North Cascade Cardiology, Director Cardiac Catheterization Laboratories, St. Joseph Hospital, 2979 Squalicom Parkway, Suite 101, Bellingham, WA 98225. E-mail: wllombardi@hinet.org
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9. Grantham JA, Marso SP, Spertus J, et al. Chronic total occlusion angioplasty in the United States. J Am Coll Cardiol Intv 2009;2:479–486.
