In the other two cases,right aortic arch coexisted withleft retro-esophageal subclavian a.or left dorsal ao rta separation.

• 左锁骨下动脉或左背主动脉经动脉导管连接或发自左肺动脉，可形成先天性肺动脉-锁骨下动脉窃血症。