Objective: To study the method of treating congenital choanalatresia.
目的：探讨治疗先天性后鼻孔闭锁的手术方法。
2
Objective: To study a new method for the treatment of congenital membranous choanalatresia.
目的：探讨治疗先天性后鼻孔膜性闭锁的新方法。
3
Objective TO evaluate the clinical effect of treatment of choanalatresia after radiotherapy in the patients with nasopharyngeal carcinoma by transnasal endoscopic surgery.