Complex anatomy surrounding the left atrial posterior wall: analysis with 3D computed tomography

Area of Science:

• Cardiology
• Radiology
• Anatomy

Background:

• Esophageal injury is a risk during atrial fibrillation (AF) ablation.
• Understanding the topographic anatomy of the esophagus, left atrium (LA), and associated fat pads is crucial for prevention.
• Multidetector computed tomography (MDCT) offers detailed visualization of these structures.

Purpose of the Study:

• To investigate the anatomical relationship between the esophagus, posterior left atrium (LA), and fat pads using MDCT.
• To identify esophageal routes and their association with LA size and fat pad thickness.
• To inform strategies for preventing esophageal injury during AF ablation.

Main Methods:

• MDCT scans were performed on 110 patients undergoing AF ablation.
• Esophageal routes were classified as leftward (Type A) or rightward (Type B).
• LA size and fat pad thickness were measured and correlated with esophageal route type.

Main Results:

• A leftward esophageal route (Type A) was identified in 90% of patients; a rightward route (Type B) in 10%.
• Type A routes were associated with larger mean LA size compared to Type B.
• Fat pads were present in 91% of patients; thinner fat pads were observed in patients with dilated LA (>42 mm).

Conclusions:

• The majority of patients exhibit a leftward esophageal route, with a significant association between LA dilatation and reduced fat pad thickness.
• Dilated LA may predispose the esophagus to thermal injury during AF ablation due to proximity and thinner protective fat.
• MDCT-based anatomical assessment can aid in mitigating esophageal injury risk during AF ablation procedures.