A Case of Anomalous Systemic Arterial Supply to the Posterior Basal Segment of Normal Lung in a Patient with Dextrocardia.

[INTRODUCTION] Dextrocardia, a condition characterized by the heart's anomalous positioning to the right, is frequently associated with venous abnormalities, but arterial anomalies are rare. In particular, systemic arterial supply to the posterior basal segment of a normal lung in dextrocardia is an exceedingly rare finding, with only one previously reported case.

[CASE PRESENTATION] A 72-year-old female with a history of colorectal and gastric cancer surgeries presented with an abnormal chest X-ray showing a left lung shadow. She was asymptomatic, with no hemoptysis, cough, or dyspnea. Contrast-enhanced chest CT revealed dextrocardia and a thick anomalous artery branching from the aorta, running as the 9th intercostal artery, and supplying the S10 region of the left lung. Venous drainage was through a hypertrophic V10 branch of the pulmonary vein, with no evidence of sequestration or arteriovenous fistulas. Bronchoscopy excluded bronchial anomalies, confirming the diagnosis of anomalous systemic arterial supply to the posterior basal segment of a normal lung. Due to the patient's carotid arteriosclerosis and risk of fatal hemoptysis, video-assisted thoracoscopic surgery was performed. The anomalous artery was transected, and visibly engorged pleural regions were partially resected. The procedure was completed in 46 min with minimal blood loss. Histopathology showed normal lung tissue with vascular wall thickening. Follow-up imaging after 2 years revealed no vascular abnormalities, and the patient remains healthy 7 years postoperatively, with no aneurysmal changes at the surgical site.

[CONCLUSIONS] We experienced a pulmonary artery originating from the aorta with perfusion only in a part of the basal segment of the lung complicated by a right thoracic heart. When preoperative angiography showed only segmental stain, it is considered safe and sufficient to resect only to the extent of the surface vasodilatation grossly during surgery.