A computed tomography algorithm for crossing coronary chronic total occlusions: riding on the wave of the proximal cap and distal vessel segment

Figures

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  Fig. 1. a–h Coronary computed tomography angiography (CTA) for clarification of proximal cap ambiguity and guiding recanalisation of the occluded venous graft for retrograde access to a chronic total occlusion. Three-dimensional CTA volume-rendered reconstruction showing the exact location of the proximal cap of a chronically occluded left anterior descending coronary artery (LAD) arising proximal to and above the septal (S) branch in the right anterior oblique (RAO) view (arrow). The exact course of the ostial LAD occlusion traversing between the septal and intermediate branch (IB) is displayed (a). Invasive coronary angiography failing to show the origin of the chronically occluded LAD (b). Advancement of the PILOT 200 guidewire (Abbott Vascular, Santa Clara, CA, USA) into the false lumen along the IB (c). Based on CTA images, the PILOT 200 guidewire was retracted and redirected pointing upwards and proximal to the septal branch, tracking the course of the LAD between the septal and IB (d). Three-dimensional CTA volume-rendered reconstruction depicting the exact location of the short stump (black arrow) as well as the course of the occluded venous graft to the chronically occluded LAD…

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  Fig. 2. a–c Coronary computed tomography angiography (CTA) for guiding balloon-assisted subintimal entry. Colour-coded CTA multiplanar reconstruction showing the exact course of severely calcified and tortuous chronic total occlusion of the right coronary artery (RCA) with adequate length of the proximal segment of the RCA for balloon-assisted subintimal entry. The coronary segments are displayed in green (no foreshortening) or red (substantial foreshortening) (a). Based on CTA reconstructions aligned with the angulation of the C‑arm, a 3.0 × 15 mm balloon was inflated in the proximal RCA, and a Fielder XT‑A guidewire (Asahi Intecc, Nagoya, Japan) was advanced into the subintimal space (b). After balloon deflation, the Turnpike Spiral microcatheter (Teleflex, Wayne, PA, USA) was advanced, and a knuckled Fielder XT‑A guidewire was pushed into mid-RCA (c). LAO left anterior oblique

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  Fig. 3. a–d Coronary computed tomography angiography (CTA) for guiding the knuckle wire technique. Colour-coded CTA multiplanar reconstructions demonstrating the exact course of a severely calcified and tortuous CTO of the right coronary artery (RCA) with clear delineation of the uptake of the right ventricular branch in right anterior oblique (RAO) 30° projection. The coronary segments are displayed in green (no foreshortening) or red (substantial foreshortening) (a, b). Based on CTA reconstructions aligned with the angulation of the C‑arm, the knuckled Fielder XT‑A guidewire (Asahi Intecc, Nagoya, Japan) supported by the Turnpike Spiral microcatheter (Teleflex, Wayne, PA, USA) was intentionally advanced along the course of the RCA, and not into the right ventricular branch (c, d). LAO left anterior oblique

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  Fig. 4. Calculation sheet for the CT-RECTOR (Computed Tomography Registry of Chronic Total Occlusion Revascularization) score with definitions of each variable and listing of the difficulty groups (reprinted with permission from [25]). CTO chronic total occlusion, PCI percutaneous coronary intervention

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  Fig. 5. Computed tomography angiography (CTA)-based hybrid algorithm for crossing a chronic total occlusion (CTO). The algorithm is based on a meticulous review of coronary CTA and dual-injection invasive angiography. Based on the premise that coronary CTA enables clear visualisation of the CTO entry relative to the further course of the occlusion site, the proximal cap does not determine the choice of either an antegrade or a retrograde strategy. Thus, only two CTO features determine whether the primary strategy is antegrade or retrograde: (1) the quality of the distal vessel; and (2) interventional collaterals. Also, occlusion length alone does not determine the choice of either a wire escalation strategy or a dissection and re-entry strategy, but rather a combination of factors including multiple occlusion sites, severe calcification (≥50% vessel cross-sectional area (CSA)), bending (≥45°), and occlusion length ≥20 mm. Swift changes of strategies are encouraged in case of failure in order to boost procedural efficiency. AFR antegrade fenestration and re-entry, LAST limited antegrade subintimal tracking, STAR subintimal tracking and re-entry

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  Fig. 6. a–g Antegrade wire escalation strategy of a chronically occluded left anterior descending coronary artery (LAD). Coronary computed tomography angiography (CTA) multiplanar reconstruction revealing a tapered proximal cap, a short non-calcified occlusion site without bending and a good distal target (a). Colour-coded CTA multiplanar reconstruction displayed in the catheterisation laboratory for guidance of antegrade wiring. The coronary segments are displayed in green (no foreshortening) or red (substantial foreshortening) (b). Baseline dual invasive angiography demonstrating a chronic total occlusion (CTO) of the ostial LAD with distal filling via collaterals from the right coronary artery (c, d). Based on the CTA-based hybrid algorithm, antegrade wiring was chosen as the primary recanalisation strategy, and the CTO was successfully crossed with a Fielder XT‑A guidewire (Asahi Intecc, Nagoya, Japan) (e). Final angiographic result after the implantation of multiple drug-eluting stents with restoration of antegrade thrombolysis in myocardial infarction grade 3 flow (f). The CTA-based hybrid algorithm for the presented case (g). AFR antegrade fenestration and re-entry, CRAN cranial,…

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  Fig. 7. a–i Antegrade dissection and re-entry strategy of a chronically occluded right coronary artery (RCA). Coronary computed tomography angiography (CTA) multiplanar reconstructions revealing short and tapered proximal cap, long and severely calcified double occlusion site (stars) with bending and a relatively good distal target with multiple calcium spots. The white arrows indicate the favourable re-entry sites within the distal RCA (a, b). Baseline dual invasive angiography demonstrating a complex chronic total occlusion of the RCA with distal filling via collaterals from the left anterior descending coronary artery supplied by the left internal mammary artery (c). Based on the CTA-based hybrid algorithm, an antegrade dissection and re-entry strategy was selected as the primary recanalisation approach, and a knuckle Fielder XT‑A guidewire (Asahi Intecc, Nagoya, Japan) was advanced to the mid-RCA (d). After antegrade insertion of a GuideLiner (Teleflex, Wayne, PA, USA), the CrossBoss catheter (Boston Scientific, Boston, MA, USA) crossed the occlusion subintimally into the distal RCA (e). Subsequently, the CrossBoss catheter was exchanged for a Stingray balloon (Boston Scientific,…