Anatomical Variations in Pulmonary Arterial Branches in Patients Undergoing Evaluation for Chronic Thromboembolic...

Catheter-based interventions have emerged for both acute and chronic pulmonary thromboembolic disease. With this development and the need for segmental cannulation, anatomic understanding of pulmonary arterial segmental branch origination is important. We aim to describe the prevalence of different pulmonary arterial segmental branch origination patterns.

This study included 179 consecutive patients who underwent bilateral nonselective invasive pulmonary angiography for the evaluation of chronic thromboembolic pulmonary hypertension.

In our study population (age, 59.0 ± 14.8 years, 55.3% female, 71% White), we found several anatomic variations of branches to the different lobes. These included 7 branching patterns in the right upper lobe, 3 in the right middle lobe, and 10 in the right lower lobe (4 patterns for the origin of the superior segmental artery and 6 for the origin of the basilar segmental arteries). On the left side, we found 8 patterns in the left upper lobe, with 5 involving lingular branches, and 9 in the left lower lobe (5 for the origin of the superior segmental artery and 4 for the basilar segmental pulmonary arteries). Although there were many variations, only 2-3 variations for each individual lobe accounted for >90% of the angiograms.

Up to 3 anatomic branching patterns per lobe were noted to account for >90% of pulmonary artery branching variations in this study. This knowledge is not only useful for the interventionalist performing catheter-directed therapies but also for future research efforts that aim to standardize reporting of pulmonary angiographic findings.