Anatomic relations between the esophagus and left atrium and relevance for ablation of atrial fibrillation.
BACKGROUND
Esophageal injury is a potential complication after intraoperative or percutaneous transcatheter ablation of the posterior aspect of the left atrium. Understanding the spatial relations between the esophagus and the left atrium is essential to reduce risks.


RESULTS
We examined by gross dissection the course of the esophagus in 15 cadavers. We measured the minimal distance of the esophageal wall to the endocardium of the left atrium with histological studies in 12 specimens. To measure the transmural thickness of the atrial wall, we sectioned another 30 human heart specimens in the sagittal plane at 3 different regions of the left atrium. The esophagus follows a variable course along the posterior aspect of the left atrium; its wall was <5 mm from the endocardium in 40% of specimens. The posterior left atrial wall has a variable thickness, being thickest adjacent to the coronary sinus and thinnest more superiorly. Behind is a layer of fibrous pericardium and fibrofatty tissue of irregular thickness that contains esophageal arteries of 0.4+/-0.2-mm external diameters.


CONCLUSIONS
The nonuniform thickness of the posterior left atrial wall and the variable fibrofatty layer between the wall and the esophagus are risk factors that must be considered during ablation procedure. Esophageal arteries and vagus nerve plexus on the anterior surface of the esophagus may be affected by ablative procedures.
Sánchez-Quintana
Damian
D
Departamento de Anatomía Humana, Facultad de Medicina, UEX, Badajoz, Spain.
Cabrera
José Angel
JA
Climent
Vicente
V
Farré
Jerónimo
J
Mendonça
Maria Cristina de
MC
Ho
Siew Yen
SY
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects* / Q000706:statistics & numerical data; D004699:Endocardium / Q000033:anatomy & histology; D004937:Esophageal Fistula / Q000209:etiology / Q000517:prevention & control; D004947:Esophagus / Q000033:anatomy & histology* / Q000293:injuries*; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006325:Heart Atria / Q000033:anatomy & histology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000033:anatomy & histology; D011183:Postoperative Complications / Q000517:prevention & control; D012307:Risk Factors