Performing posterior nostril atreoplasty is an effective method for its radical cure. Removal of the atretic septum by surgical means can be done by four routes: transnasal, transpalatal, transnasal septum, and transmandibular sinus, which should be determined by the age of the child, the degree of symptoms, the nature and thickness of the septum, and the general condition. For safety, tracheotomy can be done first. 1.Nasal approach is suitable for those whose nasal cavity is wide enough to see the atretic septum, those with thin membranous septum or bony septum, newborns or children with poor general condition who urgently need to restore compound nasal breathing. (1) General anesthesia for children and local surface anesthesia for adults. (2) Incision Make a “shaped incision” for the left nasal septum and a “shaped incision” for the right nasal septum to separate the mucosa and expose the bone surface. (3) Removal of the septum The septum is removed with a bone chisel, scraper or electric drill, preserving the mucosa behind the septum (pharyngeal side) to cover the lateral bone trauma. The posterior end of the nasal septum must be excised to allow for the foramen to pass through both sides. The size of the orifice should be such that it can pass through the index finger. A rubber or plastic tube of the appropriate size is then placed or fixed by compression with a balloon, and the duration of retention depends on the nature of the septum, from two weeks for membranous septum to 4-6 weeks for bony septum. To prevent restenosis, dilatation may be performed periodically over a year. This procedure is more convenient if performed under a nasal endoscope. In newborns, a small papillary scraper is used to scrape along the base of the nose, and the septum is removed by rotary scraping at the septum to a sufficient size, while the mucosa behind must be preserved. A cross-shaped incision is made and a rubber tube is pulled out retrograde from the nasopharynx to fix the mucosal flap on the bony surface. With the nasal approach, care should be taken to avoid damage to the descending palatine artery, skull base and cervical vertebrae during the operation. 2.Transpalatal approach The advantage is that the surgical field is well exposed, the lesion can be seen directly, the septum can be completely removed, and the mucosa can be fully used to cover the trauma, which is suitable for those with thick atretic septum. (1) Position and anesthesia The child is placed supine with the head extended backward, and 0.1% epinephrine cotton is inserted into the anterior wall of the deep atretic septum of the nasal cavity, and then a small amount of 1% procaine with epinephrine is injected at the junction of the hard and soft palate to reduce intraoperative bleeding, and general anesthesia is given through the tracheotomy. (2) Incision A semicircular incision of the Owens hard palate is made, and the mucosa is incised, with the ends of the incision reaching posteriorly to the maxillary ramus. The mucoperiosteal flap is separated to the edge of the hard palate. (3) After the posterior edge of the hard palate is revealed, a thick silk thread is passed through the freed mucoperiosteal flap for posterior traction. (4) Removal of the atretic septum The mucosa of the nasal floor behind the hard palate (nasal floor surface) is separated, and part of the bone wall of the posterior margin of the affected palate is removed with biting forceps, so that the septum can be found obliquely toward the body of the butterfly bone, the mucosa behind the septum is separated, the septum is chiseled away, and then part of the pear bone is removed at the posterior margin of the pear bone according to the method of submucoperiosteal resection of the nasal septum, so that the posterior nostril is enlarged as much as possible to ensure patency. The mucosa before and after the septum and the posterior end of the nasal septum can be used to cover the bone surface. (5) Suture the incision The mucoperiosteal flap of the hard palate incision is turned back into position and tightly sutured with fine silk thread, and if there is a tear in the hand side near the soft palate, it should also be tightly and properly sutured to avoid postoperative perforation. Finally, a rubber tube or plastic tube is placed through the anterior nostril to fix the revised intranasal mucosa, and the rubber tube is removed after 4 weeks, and regular follow-up appointments are made. If there are postoperative adhesions in the posterior nostril, they should be treated promptly and dilated if necessary. 3.Transseptal approach This method is only applicable to treat posterior nostril atresia in adults. It can be used unilaterally, bilaterally, membranous and bony. (1) Position and anesthesia Same as submucoperiosteal resection of nasal septum. (2) Incision Use a killan incision, or make an incision slightly posteriorly. (3) Dissection of the mucoperiosteum The scope should be as wide as possible, especially the upward and downward dissection, which can include the mucosa of the bilateral nasal base in order to expand the view posteriorly. (4) Incise the septal cartilage and peel the mucoperiosteum of the contralateral nasal septum, and the scope should be as wide as possible. When stripping to the posterior side, part of the septal cartilage and the vertical plate of the sieve bone can be removed, and the bony septum is removed with a bone chisel when found until the anterior wall of the pterygoid sinus can be seen. Finally, a rubber or plastic tube is inserted through the anterior nostril to prevent posterior nostril adhesions. Periodic postoperative dilation is performed if necessary. 4.Transmaxillary sinus approach This method is only applicable to unilateral posterior nostril atresia in adults, and is performed by using de Lima procedure to open the posterior group of septal sinuses from the maxillary sinus to reach the posterior nostril area and perform resection of the atretic septum.