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Subintimal Shift at the Bifurcation: A Cause of Side Branch Occlusion in Chronic Total Occlusion Intervention
Lorenzo Azzalini1, Francesco Moroni2, Ricardo Santiago3
1Division of Cardiology, VCU Health Pauley Heart Center, Richmond, VA, USA; Virginia Commonwealth University, Richmond, VA, USA.
Insights
A new mechanism called subintimal shift can cause side branch loss during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Understanding this mechanism is crucial for CTO PCI success and preventing complications like side branch loss.
Area of Science:
- Interventional Cardiology
- Cardiovascular Research
- Medical Device Technology
Background:
- Bifurcation lesions are common in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).
- These lesions are linked to reduced procedural success and increased complications, such as side branch loss.
Observation:
- A poorly understood mechanism, termed subintimal shift, contributes to side branch loss in CTO PCI.
- This occurs when a dissection plane extends from the main vessel's subintimal space into the side branch ostium.
- Subintimal shift can lead to the side branch becoming excluded during vessel preparation or stent deployment.
Findings:
- Subintimal shift is distinct from carina shift seen in non-CTO bifurcation interventions.
- This mechanism appears to be under-recognized among interventional cardiologists.
- Technical interventions like ballooning the side branch are often ineffective in restoring flow once subintimal shift occurs.
Implications:
- CTO PCI operators must be aware of subintimal shift to prevent side branch loss.
- A two-stent strategy is recommended to preserve the bifurcation when subintimal shift is suspected or occurs.
- Recognizing and addressing subintimal shift can improve procedural outcomes and reduce complications in CTO PCI.
Abstract:
Bifurcation lesions are frequently found in chronic total occlusion (CTO) percutaneous coronary intervention and are associated with lower procedural success and higher rates of complications, including side branch loss. In this report, we describe a poorly understood mechanism for side branch loss in CTO PCI: subintimal shift. This involves the extension of a dissection plane caused by subintimal (extraplaque) crossing in the main branch at the level of the side branch ostium, causing exclusion of the latter upon vessel preparation or stent placement. Subintimal shift (as compared to carina shift in non-CTO bifurcation intervention) appears to be under-recognized, and CTO operators should be aware that, from a technical standpoint, ballooning of the side branch is unlikely to restore and maintain flow, and a two-stent strategy is indicated to preserve the bifurcation.
