Several modern surgical approaches to funnel chest are available, and good results can be obtained regardless of which approach is used, but there are still many people who believe that surgery is not necessary. They believe that: cardiopulmonary abnormalities or limitations are very mild; surgery does not necessarily improve these abnormalities significantly, and in general, surgery does not improve cardiopulmonary abnormalities at all; and without surgical treatment, we do not know if and to what extent cardiopulmonary abnormalities will deteriorate further. This view makes some patients with funnel chest miss the best time for surgery and remain uncorrected until adulthood with severe thoracic deformities. With increased psychological distress, advanced Internet information, and the widespread use of minimally invasive surgery, more and more adult patients with funnel chest are seeking surgical correction. There is evidence that true physical abnormalities develop with age. Some asymptomatic patients also develop symptoms as they age. Therefore, if an adult patient with a funnel chest actively requests surgical correction, it suggests that some aspect of the patient’s life must be troubled by the funnel chest or that psychological distress exists, so we recommend surgical correction for this group of patients. Although several studies have shown that pathophysiological changes do not correlate with symptoms, slight or segmental limitation of thoracic motion and impaired oxygen delivery may cause changes in respiratory intensity. Sternal recesses may reduce thoracic volume, which can result in decreased venous oxygen saturation, physical tolerance, tidal volume, and spirometry. Reduced tidal volume may cause subjective dyspnea, decreased physical tolerance, and compensatory shortness of breath during activity. Surgically treated adult patients with funnel chest should have severe anatomic deformities and symptoms associated with funnel chest. The two most widely used surgical procedures are the modified Ravitch procedure and the Nuss procedure. The advantages of the modified Ravitch procedure are: lower cost, shorter hospital stay and less postoperative pain. It is an ideal procedure for patients with a funnel chest that is associated with a corpus cavernosum, significant asymmetry, or involvement of the superior ribs and rib cartilage. The advantages of the Nuss procedure are: short operative time, minimal bleeding, no scarring of the anterior chest, and no need to remove rib cartilage or sever the sternum. With the aid of a thoracoscope, the plate becomes visualized as it passes between the sternum and the heart, making the procedure safer. The main issues that need to be emphasized regarding the treatment of adult funnel chest are: (1) whether surgical correction can improve the appearance of the chest; (2) whether surgical correction can improve cardiopulmonary function; (3) what is the better result of the modified Ravitch or Nuss procedure. The Nuss procedure has been performed in adult patients with funnel chest, but the upper age of the procedure is not known. In adults, it is often necessary to place two plates to achieve good orthopedic results and adequate elevation of the sternum. Two plates spread the pressure from the sternum, so the risk of plate displacement is low. Up to 14% of patients require a second plate to elevate the upper sternal depression that occurred after the initial surgery or to correct plate displacement. In patients with symmetric funnel chest, the Nuss procedure achieves 100% chest wall orthopedic results. Most patients have more than 80% correction of the chest wall depression and excellent postoperative results have been reported in 85-95% of adult patients. Long-term follow-up results and risk of recurrence have not been reported. Although the traditional Ravitch procedure has satisfactory orthopedic results, the procedure is more invasive, bleeds more, takes longer, and leaves a significant surgical scar on the anterior chest wall, which makes more people choose the Nuss procedure over the Ravitch procedure. the Nuss procedure was originally designed for the treatment of pediatric funnel chest, however, we have seen that many older patients with chronic lung disease also show thoracic remodeling from a normal to a barrel-shaped chest, suggesting that there is still some plasticity in the adult thorax, and thus this procedure has been performed in adult patients with funnel chest. Although the adult thorax is stiffer and requires more force for correction, the Nuss procedure can still be successfully applied to adults with appropriate modifications, such as placement of two plates, thickened plates, and 5-point fixation. According to relevant reports, the excellent rate of thoracic appearance in adult patients with funnel chest after surgery is >90%, and the satisfaction rate of patients is also greater than 90%. 2.Improvement of physiological function in adult funnel chest after surgery Whether surgery can improve physiological function is controversial in pediatric funnel chest and unclear in adult patients. The most convincing evidence is that adult patients feel significant relief of symptoms after surgery. Reports of postoperative improvement in adults with funnel chest are limited to quality-of-life surveys, reports of subjective satisfaction, and descriptions of postoperative relief of cardiac compression in small numbers of patients. Both the modified Ravitch procedure and the Nuss procedure have shown varying degrees of symptom relief, as well as improvement in mitral valve prolapse and chest wall invagination. There is no evidence that the Nuss procedure is inferior to conventional surgery in improving physiologic function. The ideal age for Nuss surgery in adults is up to 18 years, when the thorax is more malleable and flexible, and Nuss and others suspect that the sternum is less likely to bend in older patients, so it is presumed that postoperative pain may be more pronounced and complications more frequent. There is a significant learning curve for the Nuss procedure in adult patients, with a higher incidence of complications and recurrence reported in the early years. Complications include plate displacement, plate torsion, abscess formation, pneumothorax, pleural effusion, pericarditis, and hemorrhage. In the limited number of reports of funnel chest in adults, the rates of infection, plate displacement, and recurrence are higher than in pediatric patients. With the aid of thoracoscopy, the plate becomes visualized as it passes between the sternum and the heart, making the procedure safer in all age groups. The use of more than one plate, the addition of lateral chest wall fixators and longer postoperative plate retention (>2 years) significantly reduce the chance of complications. The Nuss procedure has been reported to have a recurrence rate of 2-5% in adult patients, but the number of patients followed up is small and the follow-up time is limited. The true recurrence rate may not be known until further follow-up results are obtained, which may be close to that of the modified Ravitch procedure. When Esteves et al. used the Nuss procedure to treat adult patients over 20 years of age, they overbent the plate to achieve the desired result because intraoperatively some patients had to reshape the plate due to excessive sternal pressure. They later thickened the middle 2/3 of the plate by 30% and enlarged the fixation holes at both ends to allow for better sternal elevation and fixation. Some patients were fixed with bilateral chest wall fixators. It was later found that thickening the plate was easier to perform and the operation time was shorter. The plate rotation counterclockwise caused less intercostal injury when viewed from the right side of the patient. There was no difference in operative time, complications and length of hospital stay when comparing the group of patients >20 years old with the group of patients <20 years old. The plates were removed 3 years after surgery, and patients <20 years old were more likely to recur. 4. treatment recommendations The level of treatment for adult funnel chest has been improving with the accumulation of data and advances in surgical techniques. both the Nuss and modified Ravitch procedures have achieved symptomatic relief, improved cardiovascular function, and good cosmetic results. Based on the limited data available, the Nuss procedure is more acceptable to patients and has fewer complications than the Ravitch procedure. Despite the limited data available, we recommend that adult patients with symptomatic or impaired cardiopulmonary function undergo surgery. Surgical correction is still recommended if the sternal recess is significant and has long-term psychic implications.