Subadventitial techniques for chronic total occlusion percutaneous coronary intervention: The concept of “vessel architecture”

Abstract

Despite improvements in guidewire technologies, the traditional antegrade wire escalation approach to chronic total occlusion (CTO) recanalization is successful in only 60-80% of selected cases. In particular, long, calcified, and tortuous occlusions are less successfully approached with a true-to-true lumen approach. Frequently, the guidewire tracks into the subadventitial space, with no guarantee of distal re-entry into the true lumen. The ability to manage the subadventitial space has been a key step in the tremendous improvement in success rates of contemporary CTO percutaneous coronary intervention (PCI), whether operating antegradely or retrogradely. A modern approach to CTO PCI involves understanding the concept of "vessel architecture," which is based on the distinction between coronary structures (occlusive plaque, comprising the disrupted intima and media, and the outer adventitia) and extravascular space. The vessel architecture represents a safe work environment for guidewire and device manipulation. This review provides an anatomy-based description of the concept of vessel architecture, along with a historical perspective of subadventitial techniques for CTO PCI, and outcome data of CTO PCI utilizing the subadventitial space. © 2017 Wiley Periodicals, Inc.

Antegrade fenestration and re‐entry: A new controlled subintimal technique for chronic total occlusion recanalization

“…Second, as with any ADR technique, true lumen re‐entry might be particularly challenging in small or severely diseased vessels, regardless of the extent and number of fenestrations created between the false and true lumen. In addition, in such cases, any subintimal technique might create significant outflow disruption that will compromise runoff, which has been associated with risk of reocclusion during follow‐up . Third, if balloon dilatation is unable to create sufficient fenestrations to perform re‐entry, a large subintimal hematoma will develop and compress the true lumen, making further attempts at creating fenestrations and performing re‐entry very challenging.…”

“…Wire‐based re‐entry (STAR, LAST, etc. ) still represent valuable tools in the CTO operator toolkit. However, these should be considered as last resorts, due to little control over exact re‐entry location, significant dependence on operator's skills and experience, and inferior success rates and outcomes on follow‐up compared with a CrossBoss/Stingray‐based ADR .…”

“…Following the introduction of the CrossBoss/Stingray system (Boston Scientific, Marlborough, MA), the adoption and success rates of ADR‐based CTO PCI has increased . However, such approach is limited by high procedural costs, a steep learning curve, need for dedicated proctored training, and a non‐negligible rate of failure secondary to inability to re‐enter into the true lumen with the Stingray system (usually due to compressive subintimal hematoma).…”

Contrast modulation in chronic total occlusion percutaneous coronary intervention

“…Furthermore, it introduced the feasibility of using the subintimal space for CTO crossing, which was previously considered a forbidden territory that, when entered, often signaled the end of the procedure. The STAR technique had, however, some major limitations, such as high rates of restenosis, need for significant operator expertise and, if performed improperly, non‐negligible risk of perforation …”

“…At a median follow‐up of 209 days, the incidence of target‐lesion revascularization using first‐generation drug‐eluting stents was 29%. Contrast‐guided STAR was later abandoned, mainly due to the unpredictability of the site of true lumen re‐entry, which often led to long total stent lengths (which in turn were associated with high rates of restenosis), and loss of side branches . These factors in turn often contributed to compromising vessel runoff, which has also been associated with risk of restenosis on follow‐up …”