Is it okay to stent in the intramyocardial (within the muscle of the heart) branches?

Stenting Intramyocardial Coronary Branches

Stenting of intramyocardial branches is generally not recommended due to increased technical challenges, higher complication rates, and limited evidence supporting its routine use.

Rationale for Caution with Intramyocardial Branch Stenting

Intramyocardial branches present unique challenges for percutaneous coronary intervention (PCI) due to their:

• Smaller vessel caliber
• Increased tortuosity
• Location within the myocardium (making them more susceptible to compression)
• Limited evidence base for intervention

Technical Considerations

When approaching coronary bifurcations and branches, guidelines recommend a provisional approach:

• Stent implantation in the main vessel only, followed by provisional balloon angioplasty with or without stenting of the side branch, is recommended for PCI of bifurcation lesions 1
• Provisional side-branch stenting should be the initial approach when the side branch is not large and has only mild or moderate focal disease at the ostium 1

When Stenting Intramyocardial Branches Might Be Considered

Elective double stenting (including the intramyocardial branch) may be reasonable only in specific circumstances:

• Complex bifurcation morphology involving a large side branch
• High risk of side-branch occlusion
• Low likelihood of successful side-branch reaccess 1

Side-branch occlusion after PCI occurs in 8-80% of unselected patients and is associated with both Q-wave and non-Q-wave MI 1. Therefore, preservation of physiologic flow in significant branches is important.

Procedural Approach If Stenting Is Necessary

If stenting an intramyocardial branch becomes necessary:

1. Use drug-eluting stents (DES) over bare-metal stents (BMS) for any PCI regardless of clinical presentation or lesion type 1
2. Consider using IVUS for better assessment of vessel size and lesion characteristics 1
3. Ensure adequate vessel sizing to avoid undersizing or oversizing
4. Consider final kissing balloon inflation after elective double stenting 1
5. Be vigilant about the risk of perforation or dissection in these smaller vessels

Antiplatelet Therapy Considerations

Dual antiplatelet therapy (DAPT) is essential after stenting:

• DAPT consisting of clopidogrel in addition to aspirin is generally recommended for 6 months after stent implantation in stable coronary artery disease 1
• For acute coronary syndromes, DAPT is recommended for 12 months 1

Potential Complications

Stenting intramyocardial branches carries higher risks of:

• Perforation
• Dissection
• Stent thrombosis
• Restenosis (due to smaller vessel diameter)
• Incomplete stent expansion
• Difficulty with future reaccess if needed

Key Takeaway

While technically feasible in some cases, stenting of intramyocardial branches should be approached with caution and reserved for situations where the potential benefit clearly outweighs the risks. A provisional approach (stenting the main vessel with balloon angioplasty of the branch) is generally preferred when intervention on these vessels is necessary.