Minimally invasive surgical treatment of special types of funnel chest includes recurrent funnel chest, large flat chest plus funnel chest, asymmetric funnel chest, postoperative cardiac funnel chest, and severe funnel chest plus obese patients as special types of funnel chest, but not funnel chest combined with other diseases requiring surgery (such as combined congenital heart disease, lung or mediastinal tumors, etc.) because the former is more difficult to operate, more complex in technique, and requires more equipment and experience. The reason is that the former is more difficult, technically complex, and requires more surgical equipment and operator experience. Preliminary clinical results show that the improved funnel chest surgery has the advantages of less damage, easier operation, more accurate results, and fewer complications than the previous NUSS surgery, and is suitable for patients with various types of funnel chest, especially for patients with special types of funnel chest. Its application in the special type of funnel chest is reported as follows. Abstract: Objective: To apply the ultra-minimally invasive funnel chest correction plate and surgical method to special types of funnel chest surgery in order to simplify surgical operation, reduce surgical injury, improve surgical results, and reduce complications and patient’s pain. Patients and methods: 1. Patients: 48 patients with special types of funnel chest were admitted, including 13 cases of recurrent funnel chest, 11 cases of large flat chest with funnel chest, 16 cases of asymmetric funnel chest, 5 cases of severe funnel chest with obesity, and 3 cases after cardiac surgery. 2.Ultra-minimally invasive funnel chest orthopedic plate fixation piece and spacer (designed by Li Guoqing and Mei Ju, Department of Cardiothoracic, Xinhua Hospital, Shanghai Jiaotong University School of Medicine). 3.Ultra-minimally invasive funnel chest orthopedic surgery method. 4.Special methods: A）Partial osteotomy: amputate the deformed healed ribs protruding into the chest beside the sternum on the path of the steel plate. B）Intercostal muscle strengthening: bind the adjacent ribs on the outside at the entry and exit of the steel plate with steel wire to avoid excessive pressure on the ribs to tear the intercostal muscle. C）Separation of adhesions by small incision under the saber or simple thoracoscopic guidance. D）Use of traction band: in case of difficulty in penetrating the chest wall with the guide head (E) Dissection of partially attached ribs at the lower end of the sternum: the ribs that are partially deformed and severely affected by chest wall lifting are dissected to obtain better lifting results. Results: 2 plates were used in 5 of the 11 patients with large flat chest plus funnel chest, and only 1 plate was used in the remaining 6. 2 of the 16 patients with asymmetric funnel chest had unilateral thickened spacers, 1 had bilateral thickened spacers, and the remaining 13 were treated as usual. 2 of the 5 patients with obese severe funnel chest weighing >85 kg had a guide head with retractor cord, and the other 3 were treated as usual. In 2 of the 13 recurrences, only thoracoscopic assistance was used to separate the adhesions, and in the other 11 and 3 post-operative cardiac patients, a small subxiphoid incision was added. 3 of the recurrences underwent intercostal muscle strengthening, 1 underwent bilateral resection of the crestal augmentation of the rib cartilage, and 1 underwent bilateral partial healing rib dissection near the lower end of the sternum. In one case, a plate embedded in the bone was removed, and in the latter case, a sawing of the lower sternum was performed during cardiac surgery. The postoperative bed position was not limited and the chest radiograph showed good position of the plate. hospitalization time was 3-21. follow-up was 3-20 months and none of the cases had serious cases of complications and plate displacement. Conclusion: The improved plate and surgical method of funnel chest correction is more effective for the special type of funnel chest, and the patient can obtain a more perfect chest shape. Since the NUSS surgery was performed in 1986, the treatment results of funnel chest have been significantly improved, the recurrence rate has decreased significantly, and the operation has become easier and safer. However, the NUSS procedure is still not perfect and there is still room for improvement, especially in the treatment of special types of funnel chest. The complexity and individual differences of the special type of funnel chest pose a serious challenge to each treating surgeon, the current surgical methods and surgical equipment. We propose a new design theory of funnel chest plate, based on which we can improve the plate and surgical method, and apply the new concept, equipment and surgical method to the treatment of special types of funnel chest to obtain better treatment results. Based on a large amount of clinical data collected, orthopedic steel plates with specific curvature were designed by computer-aided design, which made it possible to produce orthopedic plates without reworking in a factory. Based on the theory that the funnel chest is a deformity of the anterior chest wall, we designed a plate that is shorter than the NUSS plate, and the application of the plate is limited to the anterior chest wall, which will not restrict the growth and development of the chest wall and cause postoperative chicken chest-like changes in the anterior chest wall, nor will it affect the patient’s sleep in the lateral position after surgery. One end of the plate, designed in a specific arc, is fused to the fixation plate and the other end is snapped to the guide head or matching fixation plate. The guide head can be removed once the guide plate is in place. The other fixation plate can be directly attached to the plate, which not only shortens the operative time, but also allows the plate to be installed under direct vision, ensuring that the plate is placed at the lowest point of the sternum and therefore ensuring efficacy. The lower edge of the fixation plate is curved, which directly transfers the force point of the plate from the intercostal muscle to the adjacent upper and lower ribs, which not only obtains more support, but also does not limit the growth of the lower ribs, so the patient’s postoperative pain is lighter and the plate is less likely to sink and flip. There are two types of spacers: thickened spacers and widened spacers. If the plate needs to be elevated on one or both sides, thicker shims can be used on one or both sides; if the length of the fixation piece on one or both sides is not long enough to make the plate stand on the two adjacent ribs, longer (symmetrical or asymmetrical) shims can be used on one or both sides. The support of steel plate is strong and stable: large steel plate is thick and wide, the support force is mainly dispersed to the adjacent two ribs, the support force is strong and stable, the recurrence, the deep depression of overweight people, the depression chest wall pressure on the steel plate is huge, with NUSS steel plate because the pressure of the steel plate on the intercostal muscle is too large, it often leads to tearing of the intercostal muscle or sinking of the steel plate, which affects the effect of surgery or leads to failure of surgery. In this case, the advantages of our plate’s strong and stable support are fully demonstrated, and none of the patients in this group had the above-mentioned results. Intraoperative plate without reversal: Intraoperative plate reversal in recurrent, overweight patients often leads to intercostal muscle tears. The use of a plate without reversal reduces intercostal muscle damage and thus greatly reduces the potential for intercostal muscle tears. Plating under direct lumpectomy ensures that the plate is positioned at the lowest point of the sternum, which ensures the therapeutic effect and eliminates the blindness during plate flipping and positioning during NUSS surgery. Slightly anterior incision: Slightly anterior incision has little effect on the concealment of the incision. The incision is moved slightly forward to avoid the distance between the lumpectomy and the operating port, which makes the lumpectomy easier to operate for the separation of intrathoracic adhesions. Intercostal muscle strengthening: Based on clinical experience or intraoperative sensation of pressure changes on the intercostal muscles during the gradual travel of the plate and reaching the maximum lifting height, if it is believed that the pressure on the intercostal muscles is too great and may lead to intercostal muscle tears or has already led to intercostal muscle tears, a wire should be applied to bind the adjacent ribs with appropriate gaps to strengthen the intercostal muscles, with the size of the gap matching the width of the plate. Subxiphoid small incision to separate adhesions and sawing of the lower sternum: The indications for subxiphoid small incision are for reoperation and heavy posterior sternal or intrathoracic adhesions. The advantage is that there is little damage, but the disadvantage is that the field is not well exposed. If there is a history of cardiac surgery and the sternum is densely adherent to the pericardium or the heart, the lower part of the sternum needs to be sawed to avoid damage to the heart or to repair the damaged heart. The treatment of asymmetric funnel chest has been controversial. Some people try to treat asymmetric funnel chest with a seagull-shaped plate, which is a plate corresponding to the lower side of the chest wall bent more curved and deeper in an attempt to make the chest wall on that side lift higher and solve the problem of chest wall asymmetry. However, the results are not satisfactory because the plate on the side with greater curvature is under greater pressure and sinks deeper, which does not achieve the expected results. In our clinical practice, we found that lifting the sternum higher is the most effective way to treat asymmetric funnel chest under current conditions, and it is easy to do so with our curved steel plate, which is designed to increase the lifting height, and the bilateral fixation piece frames the plate on the two adjacent ribs to avoid sinking of the plate and ensure the expected lifting height. If the lifting height is still insufficient on one or both sides, thicker shims can be added. Extraction of steel plate embedded in bone: the steel plate sunk into the chest cavity is mostly embedded in the bone of chest and ribs, for the steel plate embedded in the bone cannot be extracted by hard pulling, but must be rotated around until the steel plate is loosened before extraction. In conclusion, the improved steel plate and surgical method of funnel chest correction according to the new theory of funnel chest treatment have better effect on the correction of special types of funnel chest, and the patient can obtain a more perfect chest shape. Preoperative CT film Preoperative photo Postoperative lateral chest film Postoperative orthopantomogram Postoperative photo Preoperative photo Postoperative photo Postoperative photo Postoperative photo Postoperative photo