PMC5424196_01
Profile of chronic total occlusion (CTO) of the patient. (a) CTO of the proximal right coronary artery (RCA) (right anterior oblique projection). Coronary angiography revealed an anomalous origin of RCA with high anterior take-off from the aorta. (b) CTO of the proximal RCA (left anterior oblique projection). Epicardial collateral channels via the apex from the left anterior descending artery to RCA [right anterior oblique projection (c) and spider projection (d)].
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To note, there were no interventional collateral channels from the septal arteries to the distal RCA (Figure 1).
The calcified plaque blocks the entry of chronic total occlusion.
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Intecc, Aichi, Japan) and 7-Fr CLS 3.5 (Boston Scientific, Natick, MA, USA) with side holes were utilized to engage RCA and the left main coronary artery, respectively. Intravascular ultrasound (IVUS) examination from the right ventricular artery revealed that the heavily calcified plaque blocked entry of the CTO, suggesting difficulty in any guidewires penetrating into the CTO lesion (Figure 2).
The intravascular ultrasound revealed that the retrograde guidewire (white arrow) was in the subintimal space at the proximal right coronary artery past the chronic total occlusion.
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Intecc). It was advanced retrogradely into the subintimal space past CTO ostium (Figure 3).
(a) A chronic total occlusion (CTO) in the right coronary artery. (b) A Gaia Third guidewire (Asahi Intecc) is retrogradely advanced into the subintimal space past the CTO ostium. (c) An antegrade balloon-assisted subintimal reentry is performed, which is created proximally to the occluded segment using a large balloon. (d) The retrograde guidewire successfully penetrated the proximal true lumen.
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Third guidewire was entered, successfully penetrating the proximal true lumen (Figure 4) and reaching the aorta in a retrograde manner (Movie 3).
Intravascular ultrasound (IVUS) examination. IVUS was performed after guidewire externalization. Serial IVUS images of right coronary artery (RCA) show the ostial RCA (a), the guidewire entering into the true lumen from the false lumen at the proximal RCA (b), and the guidewire passing the chronic total occlusion (CTO) segment through the subintimal space, avoiding the severely calcified plaque at the proximal segment of CTO ((c)-(e)). Images are viewed in a proximal (a) to distal (e) direction.
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The Corsair Pro was advanced similarly, followed by retrograde guidewire externalization with an RG3 300 cm guidewire (Asahi Intecc). The IVUS showed that the externalized guidewire traversed the CTO lesion, avoiding the heavily calcified plaque of the ostium (Figure 5).
A final angiogram reveals an acceptable outcome. Serial intravascular ultrasound images of right coronary artery (RCA) after stenting show the ostial RCA (a), RCA proximal to chronic total occlusion (CTO) (b), and the CTO segments ((c)-(e)). Images are viewed in a proximal (a) to distal (e) direction. Adequate stent expansion is achieved throughout the lesion, except elliptical stent expansion limited by a superficial calcified lesion at the calcified proximal cap of CTO (c).
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Afterwards, four drug-eluting stents were sequentially deployed from the distal to proximal RCA, and the final angiogram provided assurance, thereby allowing the procedure to be completed without any complications (Figure 6).