Funnel chest is the most common thoracic deformity, which compresses the heart in severe cases, reduces lung capacity and affects cardiopulmonary function; at the same time, it affects aesthetics and may cause psychological barriers to patients, and requires surgery for correction. The Nuss procedure is a minimally invasive treatment of funnel chest first reported by Nuss in 1998, and has been highly recommended at home and abroad, mainly for the correction of pediatric funnel chest. Since the ossification and cognitive characteristics of youth and adolescent funnel chest are different from those of pediatric patients, we have partially modified the Nuss procedure since 2007 to adapt to the correction of adolescent funnel chest, and achieved good results. The patient’s mid-axillary line distance was measured with a soft ruler before surgery, and an orthopedic plate of the appropriate size was selected. The operation was performed under general anesthesia with double-lumen tracheal intubation. The patient was placed in the supine position with both upper limbs abducted at 90°. Two small 2.5 cm incision marks were made at slightly higher levels of the most concave part of the sternum in the mid-axillary line on each side, and also at the highest intercostal area at this level (this was used as the site for penetration and exit of the orthopedic plate), and the orthopedic plate was bent and shaped along the anterior chest wall. Single-chamber ventilation was ordered to collapse the right lung, and a 30° thoracoscope was placed 1-2 intercostal spaces below the small incision on the right side to observe the thoracic cavity. A tunnel was made along the gap between the pectoral muscle and subcutaneous tissues at both sides of the small incision separated to the mark of the highest point of the rib cage. The penetrator was placed into the right thoracic cavity along this tunnel, and the posterior aspect of the sternum was carefully separated under the surveillance of the thoracoscope, and the penetrator was passed through the posterior aspect of the sternum and then passed out at the mark of the highest point of the intercostal space on the opposite side and tunneled out on the opposite side. The deformed chest wall is corrected by tying the shaped orthopedic plate to the penetrator with the arch facing posteriorly and returning the penetrator along the original path, i.e., placing the orthopedic plate on both sides of the thoracic cavity, turning the plate so that the arch faces upward and jacking up the sternum. After thoracoscopic observation, the orthopedic plate was satisfactorily positioned and there was no active bleeding behind the sternum. The orthopedic plate was fixed with a small steel plate with grooves on the right side, and on the left side, the orthopedic plate was sutured and fixed to the muscle tissue, and the orthopedic plate was sutured to the ribs between the bilateral orthopedic plate entry and exit points of the chest cavity and the end fixation points. A closed chest drain was placed through the thoracoscopic observation hole. The tracheal intubation was removed after awakening from anesthesia. The patient was routinely given an analgesic pump. Postoperative management: review chest radiographs (frontal and lateral) to observe the condition of the chest cavity, the position of the orthopedic plate, and to measure the postoperative sternal depression. Generally, the chest drain was removed on the first day after surgery; attention was paid to strengthening analgesia; strenuous exercise was avoided for 3 months; if needed, the orthopedic plate could be removed after 3 years, or left in place for a long time. The results were graded into four levels: complete normalization of the thorax without residual sternal depression was considered excellent; the presence of mild funnel chest was considered good; the presence of moderate funnel chest was considered fair; and the apparent presence of funnel chest or recurrence was considered poor. Results: All patients completed the surgery successfully and the placement of orthopedic plates was satisfactory. The operative time ranged from 100 to 210 min, with an average of 145 min, with the two cases of recurrent funnel chest having the longest operative time. Intraoperative bleeding was low, and the total amount of drainage fluid was less than 100ml before the drainage tube was removed; postoperative hospitalization time was 6-19d, with an average postoperative hospitalization day of 8.8d. There were no complications such as pneumothorax, no cardiac or pericardial injury in the whole group of patients, and no displacement or collapse of the orthopedic plate was found to occur. 3 cases with pain for more than 1 week, the pain was mainly in the position where the orthopedic plate was fixed on both sides; 1 case was a poorly healed wound on the right side, which was One case was a poorly healed wound on the right side, which healed after re-suturing. All patients were followed up for 2-19 months, with excellent orthopedic results in 6 cases and good results in 2 cases; all patients had no significant discomfort and normal activities; no orthopedic plate displacement or collapse, and no injurious events occurred. Discussion: Adolescent ossification characteristics and the modified method of Nuss surgery. Since the ossification of the sternum and ribs in adolescents is close to adult or completely ossified and set, the degree of difficulty in shaping is much higher than in pediatric patients, and the orthopedic surgery for funnel chest requires significantly higher support and fixation of the orthopedic plate, and the possibility of displacement and collapse of the placed orthopedic plate increases. kim [3] performed a retrospective analysis of the results of patients undergoing Nuss surgery in different age groups and concluded that Nuss surgery is effective in correcting pediatric However, in adolescent and adult patients, cases need to be selected with caution, mainly because of the long operation time and the number of complications. The need for reoperation was 3.7% (1/27) in the pediatric group, 16.6% (2/12) in the adolescent group, and 41.7% (5/12) in the adult group. Therefore, we modified the surgical approach and postoperative management to accommodate adolescent patients, reduce complications, and aim to improve orthopedic outcomes. The placement of the orthopedic plate was slightly adjusted during surgery, not at the lowest point of the sternal depression (because the lowest point of the ossified or nearly ossified sternum is very hard and can easily make the orthopedic plate slip out), but at its slightly higher, relatively flat position of the sternum, so that the stability is good and the possibility of displacement is small, and from the postoperative observation of the whole group, there was no case of displacement or depression of the orthopedic plate. In addition to fixation of the orthopedic plate on the right side, we also fixed the orthopedic plate with sutures to the ribs between the entry and exit points of the thoracic cavity and the end fixation points of the orthopedic plate on both sides. There are reports of cases where double orthopedic plates or even three orthopedic plates were used to correct severe funnel chest in order to prevent displacement of the plates, with satisfactory results. We have adjusted the time of removal of the orthopedic plate, suggesting that it should be removed 3 years after surgery, and that it should not be removed in patients with complete development or basic stereotypes without special circumstances, because no adverse effects have been reported after long-term placement of the orthopedic plate. Prevention and management of complications: The general complications of Nuss surgery include pain, pneumothorax, pleural effusion, and pneumonia. The main complication in this group was pain, and the location of the pain was mainly at the bilateral orthopedic plate fixation. Most patients had pain relief within 1 week, and one patient had pain for more than 2 weeks, which affected sleep and rest and led to significant weight loss, which was relieved by symptomatic treatment. Pleural effusion is a common complication, and many authors believe that the procedure does not require the placement of a chest tube, but we feel that the placement of a chest tube in the thoracoscopic observation hole facilitates 24-h postoperative observation of the chest cavity and is safer and more reliable, and all patients in the group were removed on the first postoperative day, which had no major impact on early postoperative activities and prevented the occurrence of postoperative pneumothorax, subcutaneous emphysema, and pleural effusion. Special complications of the Nuss procedure, including collapse and displacement of the orthopedic plate, as well as penetration of the heart and lungs, have been reported in the literature. Collapse and displacement of the orthopedic plate is the most important reason for the failure or poor outcome of Nuss surgery, and is related to the selection of the orthopedic plate, its placement, and fixation method, etc. Croitoru reported 26 cases (8.6%) of collapse and displacement of the orthopedic plate in 302 surgeries. Therefore, we made improvements in the stability of the orthopedic plate, and no complications regarding the orthopedic plate were seen in all patients during the follow-up period, with good orthopedic results. Penetration of the heart and lungs is a serious complication of this procedure, so the procedure of penetrating the posterior sternal tissue is one of the key steps of the procedure and should be done with care, and the chance of this complication is significantly reduced with thoracoscopic observation. To avoid this complication, a small incision can be made under the glabella to first separate the posterior sternal tissues to create conditions for the penetrator to pass through the posterior sternum without damaging the heart, which is also a good option.