Large anomalous systemic arterial supply to basal segments of the left lung.

A 29-year-old man with a large anomalous systemic arterial supply to basal segments of the lower lobe was reported here. Pulmonary arteriography showed the absence of blood flow to basal segments. Aortography verified the anomalous artery from the descending thoracic aorta. Lobectomy was performed because the anastomosis between the anomalous and pulmonary arteries was anatomically difficult and segment 6 was small. The resected specimen showed that the anomalous artery had findings of pulmonary hypertension equivalent to grade V in the classification of Heath and Edwards. If the anastomosis between the anomalous and pulmonary arteries is anatomically feasible, pathological examination of open lung biopsy specimen is necessary to determine the operative procedures in this disease and two-staged operation is desirable.