A New Algorithm for Crossing Chronic Total Occlusions From the Asia Pacific Chronic Total Occlusion Club

Abstract

Although the hybrid chronic total occlusion (CTO) algorithm had many excellent recommendations, there has been infrequent adoption in the Asia Pacific region. The Asia Pacific CTO club propose an algorithm for case selection based on the Japan-CTO score and a new CTO algorithm, which is applicable globally. This algorithm allows for differing skill sets and equipment availability and contains practical teaching for CTO percutaneous coronary intervention. Similar to the hybrid algorithm there are 3 main questions that determine whether the primary approach is antegrade or retrograde: 1) is there proximal cap ambiguity; 2) is the distal vessel of poor quality; and 3) are there interventional collaterals present. In contrast to the hybrid algorithm occlusion length alone does not determine the choice of either a wire escalation strategy or a dissection re-entry strategy. Rather a combination of factors including ambiguity of the vessel course, severe calcification, tortuosity, length, and previous failure are used to determine this. The role of intravascular ultrasound-guided entry to overcome proximal cap ambiguity and the CrossBoss catheter in occlusive in-stent restenosis are highlighted in the algorithm. Both the parallel wire technique and dissection re-entry with the Stingray system have been included as options when the initial antegrade wire passage fails. Intravascular ultrasound-guided wiring along with limited subintimal tracking and re-entry are included as final options in the algorithm. Finally, the algorithm incorporates guidance on when to stop the procedure. It is hoped that this algorithm will serve as the basis for future CTO percutaneous coronary intervention proctoring and training.

Procedure failure of chronic total occlusion percutaneous coronary intervention in an algorithm driven contemporary Asia‐Pacific Chronic Total Occlusion Club (APCTO Club) multicenter registry

“…This can be achieved despite high mean J‐CTO score (2.9) with >65% very difficult (> = 3) cases and high prevalence of reattempt lesions (>38% cases). Our cohort has high prevalence of IVUS guided CTO wiring (37%) in resolving proximal cap ambiguity, IVUS guided reverse CART, and IVUS guided antegrade reentry in line with the algorithm from the Asia Pacific Chronic Total Occlusion Club …”

“…In these registries, procedural failure was due to the inability to cross the lesion with a guidewire in 70% of cases, or less commonly in 30% of cases, due to a complication . Examination of failed cases and mode of failure can inform and improved our success rates further, therefore, we examined the failed cases in an algorithm driven approach contemporary multicenter CTO registry …”

Assessment of reattempted percutaneous coronary intervention strategy for chronic total occlusion after prior failed procedures: Analysis of the Japanese CTO‐PCI Expert Registry

“…We suggest that it is very important to determine the strategy for a reattempt CTO‐PCI with reference to information learned from the initial failed procedure, the expansion of the subintimal space, and the possible complications. Recent reports suggest that a strategy can be determined from algorithms, but we do not recommend this approach. The present study does not evaluate the details and operator experiences of previously failed procedures.…”

“…The development of techniques and devices has improved the initial success rate of CTO‐PCI . Recently, the adaptation of algorithms based on angiographical classifications promotes the standardization of strategies in CTO‐PCI procedures . It is widely known that operator's experience and expertise greatly influence the success of CTO‐PCI procedures .…”

Antegrade fenestration and re‐entry: The legacy continues

“…Antegrade techniques are usually favored because retrograde crossing carries higher risk for complications . The hybrid algorithm to CTO crossing favors use of ADR, especially the Stingray system, whereas the Asia Pacific algorithm favors use of parallel wiring . Re‐entry using the Stingray is preferred over STAR or other wire‐based techniques, because it is more predictable and limits the extent of dissection, whereas STAR is only used as a last resort due to extensive loss of side branches, resulting in high restenosis and re‐occlusion rates.…”