Posterior wall thickness of the confluent inferior pulmonary veins
measured by left atrial intracardiac echocardiography: Implications for
Backgrounds. Fusion of the left and right inferior pulmonary
veins (PV) (confluent inferior PV, CIPV) is a rare variation. Using
intracardiac echocardiography (ICE) from the left atrium (LA), we
measured the posterior wall thickness (PWT) of CIPV adjacent to the
esophagus and compared it with LA posterior wall thickness (LAPWT) in
non-CIPV cases. Methods. Of the consecutive 986 patients
undergoing atrial fibrillation (AF) ablation from July 2020 to June
2022, seven (0.7%) had CIPV with a common trunk connecting to the LA
diagnosed by 3-dimentinal contrast-enhanced computed tomography.
Twenty-five AF patients without CIPV served as control. ICE was done
from LA to measure PWT of CIPV and LAPWT of non-CIPV cases at the level
of the left inferior PV. For ablation in CIPV patients, each superior PV
was individually isolated, and BOX isolation of CIPV without ablating
CIPV posterior wall was added. Results. CIPV PWT was 0.7±0.1
mm, while LAPWT of non-CIPV was 2.0±0.4 mm (P<0.001). In CIPV
group, the upper and lower portions of CIPV were both apart from the
esophagus (mean distances, 6.7±3.4 mm and 7.9±2.7 mm, respectively).
Individual superior PV isolation and BOX CIPV isolation resulted in
complete isolation of all PVs. There were no complications. All CIPV
patients but one remained free from AF recurrence for 376±52 days.
Conclusions. Although CIPV frequency is low (0.7%), CIPV PWT
is very thin and a special care is needed in ablation. The present
ablation strategy is effective for complete PV isolation with a less
risk of the esophageal injury.