診断に苦慮した末梢型肺動脈瘤破裂による大量の気道内出血に対しV–V ECMO下での肺葉切除術が奏功した1例(Diagnostically challenging ruptured peripheral pulmonary artery aneurysm presenting with massive airway hemorrhage treated with V–V ECMO–supported lobectomy: a case report)