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

Unique segmental branching of right pulmonary artery in association with patent ductus arteriosus and anomalous carotid origin of left vertebral artery

“…The posterior segmental artery (A2) arises distal to the truncus anterior 1 . However, in the current case, there is a separate origin of all the segmental arteries of right upper lobe from the RPA, consistent with the type‐3 branching pattern which is rare 2 . To the best of our literature search, we did not find any association between the aberrant branching pattern of RPA and patent ductus arteriosus, although an angiocardiographic study has highlighted the importance of RPA branching patterns in various cardiovascular anomalies such as situs inversus, tetralogy of Fallot, aortopulmonary window, double outlet right ventricle, single ventricle, and so on 3 .…”

“…1 However, in the current case, there is a separate origin of all the segmental arteries of right upper lobe from the RPA, consistent with the type-3 branching pattern which is rare. 2 To the best of our literature search, we did not find any association between the aberrant branching pattern of RPA and patent ductus arteriosus, although an angiocardiographic study has highlighted the importance of RPA branching patterns in various cardiovascular anomalies such as situs inversus, tetralogy of Fallot, aortopulmonary window, double outlet right ventricle, single ventricle, and so on. 3 It is imperative to note that the pulmonary arteries and the ductus arteriosus are both embryologically derived from the left sixth aortic arch, which could explain the co-existence of variant pulmonary arterial anatomy and patent ductus arteriosus in our case.…”

“…(A) Three‐dimensional volume reconstructed image (left anterolateral view) and (B) oblique sagittal maximum intensity projection image showing the patent ductus arteriosus (asterisks), between the descending thoracic aorta and main pulmonary trunk. The aorta showed normal branching pattern with origin of the left vertebral artery (white line arrows) from the left common carotid artery 2 . 1‐Right brachiocephalic trunk, 2‐ Left common carotid artery, 3‐ Left subclavian artery.…”

“…Accessory nonazygous fissure of the right upper lobe is also very rare, and is mentioned in a few case reports. Although these findings may be incidental, knowledge of such anatomic variations is important, in the background of congenital cardiovascular diseases and for planning catheter‐based therapies 2 …”

Status and Future Directions for Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Disease With and Without Pulmonary Hypertension: A Scientific Statement From the American Heart Association

“…It has a variable branching pattern and does not divide like its counterpart on the right and merely runs in the interlobar fissure on the left side. 14,15 Each lung is divided into 10 segmental zones, with the main segmental origin coming from either the superior or inferior trunk on the right side and the left main pulmonary artery interlobar trunk on the left side. Segmental anatomy is similar in both lungs with a few caveats:…”