Response to ‘coronary bifurcation stenting: selection of technique, side-branch protection, and prognostically relevant side branch’

We thank Guner et al. for their comments on our case report describing intravascular ultrasound (IVUS)-guided tip-detection antegrade dissection and re-entry (TD-ADR) as a bailout strategy for calcification-induced side-branch occlusion during complex percutaneous coronary intervention (PCI).^1,2 We agree that the value of this discussion lies not in retrospective justification of a single procedural decision, but in clarifying how important side-branch compromise may be anticipated, interpreted, and managed during calcified bifurcation PCI.

First, angiographic identification of the target branch to be protected is essential. In our case, considering the perfusion territory, D2 was the side branch that should have been protected. However, guidewire manipulation was directed easily towards D1, whereas selective wiring into D2 was difficult. At the time of the procedure, D1 and D2 were interpreted as arising from a common take-off, leading to the assumption that securing D1 would also protect D2. However, the subsequent course suggested that D1 and D2 originated from different ostia, and antegrade flow was lost in D2. Although angiographic assessment remains fundamental for anatomical understanding, intracoronary imaging can reinforce that assessment. Intravascular ultrasound or optical coherence tomography may provide information regarding side-branch take-off anatomy, plaque eccentricity, carina–plaque relationships, and side-branch ostial morphology, thereby refining procedural planning.³

Second, the mechanism of side-branch occlusion in this case appears to differ from previously reported predictors. Contemporary imaging-based studies suggest that side-branch compromise is associated with geometric and morphologic features of the bifurcation, including side-branch size, the configuration of the bifurcation core, and the spatial relationship between the carina and side-branch ostium.⁴ In our case, however, IVUS suggested that D2 occlusion was related not simply to these factors, but to displacement of fractured calcific plaque after lesion debulking and subsequent dilation with a modified balloon.¹ This observation may have practical relevance, because operators should remain aware that, after calcium modification, altered calcific components may obstruct an adjacent side branch during further lesion preparation.

Third, once the side-branch guidewire had entered the false lumen and angiography-guided recrossing proved unsuccessful, the procedural objective changed from protection to restoration of true-lumen access. In such a situation, IVUS-guided TD-ADR should be recognized as a bailout option. Recent expert consensus and case-based experience suggest that IVUS-guided re-entry strategies may be useful when conventional angiographic recrossing is not feasible after subintimal passage.^5,6

Finally, the final stenting technique should be tailored pragmatically according to the bifurcation anatomy, the wire position achieved after rescue, procedural feasibility, and operator familiarity with the available techniques.^3,5 In our case, once true-lumen access to D2 had been restored, culotte stenting was selected as a reasonable and anatomically suitable reconstructive strategy.

We therefore believe that the educational message of this case is threefold: accurate angiographic identification of the target side branch is essential and may be reinforced by intracoronary imaging; side-branch occlusion after calcium modification may occur through mechanisms not fully captured by previously recognized predictors; and, when false-lumen passage makes angiography-guided recrossing unsuccessful, IVUS-guided TD-ADR may serve as a useful bailout option.

Author contributions

Kei Kawai (Writing—original draft [lead]) and Kazuhiro Ashida (Writing—review & editing [supporting])

Funding

None declared.

Data availability

No new data were generated or analysed in support of this correspondence.