Left atrial appendage and pulmonary artery anatomic relationship by cardiac-gated computed tomography: Implications...

Delayed pulmonary artery (PA) perforation and tamponade caused by implantable left atrial appendage (LAA) closure devices has been reported in patients with close proximity between these structures. The LAA and PA anatomic relationship (LAA-PAar) has not been analyzed systematically.

The purpose of this study was to identify LAA-PAar variants potentially susceptible to this complication using cardiac-gated computed tomography angiography.

We studied 100 consecutive patients with atrial fibrillation undergoing cardiac-gated computed tomography angiography of the left atrium. The LAA-PAar was classified into 3 types on the basis of the location, length, and thickness of the segment of contact between the PA and/or its branches and the LAA: type 1, no contact; type 2, contact involving the proximal LAA (defined as the proximal 15 mm extending into the LAA from its ostium, or the LAA proximal to the first major bend arising <15 mm from the ostium); and type 3, contact limited to the distal LAA.

LAA-PAar types 1, 2, and 3 were present in 7 (7%), 28 (28%), and 65 (65%) patients, respectively. For LAA-PAar type 2, the mean contact segment thickness and length were 0.6 ± 0.3 and 18.1 ± 10.6 mm, respectively. For LAA-PAar type 3, the distance between the LAA orifice and the segment of contact was <30 mm in 52 patients (80%).

In this series, the LAA came in direct contact with the main PA in the majority of patients. Contact involved the proximal LAA (where the fixation components of most LAA closure devices are positioned) in 28% of patients, posing potential vulnerability to PA perforation.