# Anomalous Systemic Arterial Supply to the Basal Segments with an Aneurysmal Aberrant Artery Showing Advanced Wall Fragility: A Case Report and Literature Review

## TL;DR

A rare case of anomalous systemic arterial supply to the lungs was safely treated with a two-step approach involving TEVAR and lobectomy, preventing potential rupture.

## Contribution

This is the first reported case of ASABS with aneurysmal aberrant artery where histopathological findings confirmed rupture risk and TEVAR-first strategy was successfully applied.

## Key findings

- TEVAR-first strategy enabled safe pulmonary resection in ASABS with aneurysmal aberrant artery.
- Histopathology confirmed aneurysmal degeneration and increased rupture risk in the aberrant artery.
- Postoperative imaging confirmed no complications like endoleak or stump aneurysm.

## Abstract

Anomalous systemic arterial supply to the basal segments (ASABS) is a rare congenital pulmonary anomaly. Considering the associated complications of pulmonary hypertension or hemoptysis, surgical lung resection is recommended. However, there is a lack of standardized surgical management guidelines. We report a case of ASABS with an aneurysmal aberrant artery, in which imaging findings suggested an increased risk of rupture. Thoracic endovascular aortic repair (TEVAR) was first performed to achieve inflow control; this strategy provided a secure setting for subsequent pulmonary resections.

A 56-year-old woman presented with an abnormal chest shadow. Contrast-enhanced chest CT revealed an aberrant artery arising from the descending aorta supplying the left basal segment with an irregular aneurysm measuring 33 mm. Non-contrast chest CT demonstrated intraluminal hyperattenuation consistent with acute thrombosis, raising concerns regarding an increased risk of rupture. The absence of a normal pulmonary arterial supply to the basal segment and normal bronchial and pulmonary venous anatomy confirmed the diagnosis of ASABS. Given the radiologic findings suggestive of an increased risk of rupture of an aberrant artery, preoperative TEVAR was performed to control the inflow to the aberrant artery. After 18 days, video-assisted left lower lobectomy with division of the aberrant artery was performed safely. The postoperative course was uneventful, and the patient was discharged 10 days after surgery. Pathology revealed disruption of the elastic fibers and thinning of the media, supporting aneurysmal degeneration at the risk of rupture. Contrast-enhanced CT performed 6 months after surgery confirmed the absence of an endoleak or stump aneurysm.

The TEVAR-first approach for inflow control enabled safe pulmonary resection in ASABS with an aneurysmal aberrant artery. To the best of our knowledge, this is the first reported case for this condition where histopathological findings suggested an increased risk of rupture. Further investigation is needed to determine which patients benefit the most from this strategy and to understand the long-term outcomes.