Beyond Fluoroscopy: How 3D TEE Guides Coronary Sinus Cannulation in Structural Heart Interventions

Introduction

The coronary sinus (CS) has become a critical anatomical structure in modern cardiology, especially in:

• Cardiac resynchronization therapy (CRT)
• Arrhythmia ablation
• Percutaneous mitral interventions (e.g., CARILLON annuloplasty)

However, coronary sinus cannulation can sometimes be challenging using:

• Fluoroscopy
• 2D transesophageal echocardiography (TEE)

This is where real-time three-dimensional TEE (3D TEE) offers a major advantage.

📄 Original Research Article (PubMed)

Read the original publication here:
👉 https://pubmed.ncbi.nlm.nih.gov/25231878/

🎥 Watch: How to Image the Interatrial Septum (RATLe-90 Maneuver)

Since coronary sinus cannulation depends heavily on accurate interatrial septum (IAS) orientation, mastering IAS imaging is essential.

👉 Watch this open-access CIC lecture:
https://ciceg.net/courses/online-advanced-echocardiography-course/lessons/how-to-image-the-inter-atrial-septum-using-3d-tee-ratle-90-maneuver/

🎯 This lecture shows:

• How to obtain an anatomically oriented IAS view
• How to apply the RATLe-90 maneuver
• Practical steps for real cath lab guidance

Clinical Case Overview

A 78-year-old female with severe symptomatic mitral regurgitation underwent:

👉 Percutaneous CARILLON mitral annuloplasty

🔴 Problem:

• Multiple failed attempts at CS cannulation
• Despite:
  • Fluoroscopy
  • 2D TEE guidance

The Solution: Real-Time 3D TEE

Using 3D TEE zoom mode:

• The dataset included:
  • Interatrial septum
  • SVC
  • IVC
  • Eustachian valve
• The volume was rotated to obtain:
  👉 En face view of IAS from right atrial perspective

📌 As clearly shown in the images on page 2, this view allowed direct visualization of the CS ostium adjacent to the eustachian valve

Step-by-Step Cannulation Strategy

1. Identify Anatomical Landmarks

• SVC (superior)
• IVC (inferior)
• Eustachian valve
• Coronary sinus ostium

2. Orient the View Anatomically

➡️ Keep:

• SVC → superior
• IVC → inferior

(This is exactly the concept taught in the RATLe-90 maneuver)

3. Catheter Navigation

• Advance catheter from SVC → RA
• Direct toward eustachian valve
• Move anteriorly → align with CS opening
• Advance inferiorly → successful cannulation

📌 Demonstrated in Figures 2 & 3, showing catheter movement into the CS

Why 3D TEE Was Superior

❌ Limitations of Fluoroscopy & 2D:

• Limited anatomical detail
• Loss of catheter tracking outside plane
• Multiple failed attempts

✅ Advantages of 3D TEE:

1. En Face Anatomical View

• True spatial orientation

2. Direct Visualization of CS Ostium

• No guesswork

3. Real-Time Catheter Tracking

• Continuous guidance

4. Reduced Radiation Exposure

• Less dependence on fluoroscopy

Key Insight: The Importance of IAS Imaging

This case highlights a crucial concept:

👉 Successful CS cannulation starts with proper IAS visualization

Using techniques like:

• RATLe-90 maneuver
• 3D en face orientation

You create:

✔️ A shared spatial understanding
✔️ Better communication with interventionist
✔️ Faster, safer procedures

Clinical Applications

This approach is valuable in:

• CARILLON annuloplasty
• CRT lead placement
• Ablation procedures
• Structural heart interventions

From Technique to Standard Practice

Although this is a single case, the implications are significant:

💡 3D TEE should be considered when:

• Cannulation is difficult
• Anatomy is complex
• Fluoroscopy is insufficient

🎓 Learn Advanced 3D TEE & Structural Echo

If you want to master:

• IAS imaging
• Coronary sinus anatomy
• Transseptal & catheter guidance
• Structural heart procedures

👉 Explore CIC Online Echocardiography Courses:
🔗 https://ciceg.net/cic-courses/

✔️ Real clinical cases
✔️ Practical step-by-step training
✔️ On-demand access
✔️ Designed for cardiologists worldwide

Conclusion

This case demonstrates the incremental value of real-time 3D TEE in guiding coronary sinus cannulation.

By providing a true anatomical en face view, 3D TEE:

• Improves procedural success
• Reduces radiation exposure
• Enhances safety

It reinforces a key principle:

👉 “If you see anatomy correctly… you guide intervention correctly.”