Surgical correction of pectus excavatum and carinatum

The author presents three decades of experience in the management of anterior chest wall deformities. During this period more than 800 operations were performed on patients with pectus excavatum and carinatum. In this series, there was no death and serious complications were rare. The author believes that the principles on which surgical treatment of pectus excavatum should be based are as follows: (1) bilateral removal of the "culprit" costal cartilages, (2) adequate mobilization of the sternum and correction of the sternal positional deformity by transverse osteotomy, (3) stabilizing the corrected position of the sternum with a substernal "hammock" support. Using this technique the author developed new surgical techniques for the correction of different varieties of chest wall deformities: Pectus excavatum, asymmetric pectus excavatum, pectus carinatum with xiphoid angulation, horizontal pectus excavatum, asymmetric pectus carinatum, chondrosternal prominence with chondrogladiolar depression, and recurrent pectus excavatum. The present method applied for correction of pectus excavatum utilizes the above principles and a substernal Marlex mesh support with bilateral muscle coverage. For carinatum repair, the author routinely uses positional correction of the sternum and sternal shortening. Patients who have significant pectus deformities should undergo surgical repair, preferably between one and eight years of age.     

Management of a floating sternum after repair of pectus excavatum

PURPOSE: The aim of this study was to examine the authors' experience with patients who have floating sternum after correction of pectus excavatum via the classical Ravitch procedure. A floating sternum is defined as a sternum in which the only attachment to the chest wall is its superior (cranial) border, and in which the body is secured only by the manubrium and whatever lateral and inferior fibrous bands are present. Typically, a floating sternum is caused by either extensive resection of the costal cartilages and perichondrium during correction of pectus excavatum or failure of proper regrowth of these cartilages. METHODS: The authors retrospectively assessed the charts of all patients diagnosed with a floating sternum noting age at original correction of pectus excavatum, time from original correction of pectus excavatum to diagnosis of floating sternum, age at correction of floating sternum, complaints before stabilization of the sternum, methods of repair, and postoperative complications. RESULTS: Between July 1993 and June 1999, floating sternum was diagnosed in 7 patients. The mean age of patients who underwent operative correction of a floating sternum was 28.9 years (range, 16 to 42 years). The mean time interval between original correction of pectus excavatum, or "redo," and diagnosis of a floating sternum was 9.9 years (range, 2 to 20 years). Complaints before correction of the floating sternum included sternal pain and instability, exercise intolerance, and difficulty breathing. Operative repair consisted of mobilizing the lateral and inferior edges of the sternum, detaching the fibrous perichondrium, performing anterior sternal osteotomies, and finally supporting the sternum with substernal Adkins struts. All 7 patients had successful stabilization of the sternum. Two of 7 patients underwent 2 procedures to successfully stabilize the sternum. One patient has Adkins struts still in place because of hematopoetic malignancy. Six of 7 patients are now without symptoms. CONCLUSIONS: A floating sternum is a morbid phenomenon that may manifest many years after the original procedure. It can cause significant sternal pain, chest wall instability, and respiratory dysfunction, which are the hallmark indications for correction. Repair of a floating sternum can be accomplished successfully.     

Modified Ravitch procedure: using a pectus bar for posttraumatic pectus excavatum

Guidelines for surgical management of posttraumatic pectus excavatum have not been established due to the variable clinical manifestations and limited number of cases. A 34-year-old man who was involved in a truck-mixer vehicle crash 6 months previously complained of a depressed anterior chest wall deformity. The patient had successfully undergone subperichondral resection, sternal osteotomy, and pectus bar insertion placed under the depressed sternum, followed by bar rotation for elevation of the chest wall. This case illustrates that a modified Ravitch procedure, using a pectus bar, may be an alternative for posttraumatic pectus excavatum.     

Anterior chest wall deformities and congenital heart disease

Pectus excavatum and pectus carinatum usually exist as isolated abnormalities. Only 19 cases of associated congenital heart defects have been reported. Significant complications related to uncorrected pectus excavatum have been described either during or after cardiac operations. Therefore we reviewed our experience with these coexisting lesions to assess the risk of surgical repair of chest wall deformities before and after correction of congenital cardiac anomalies. Among 20,860 infants and children with congenital heart disease seen at our institution, 36 (0.17%) had associated anterior thoracic deformities, 22 of whom underwent surgical correction of pectus excavatum or pectus carinatum. Ten of these 22 patients had pectus repair after a cardiac operation. Pleural or pericardial entry was avoided in all and none required a blood transfusion. Ten other patients had pectus repair either before cardiac repair (five patients) or without a subsequent cardiac operation. Another patient had a cardiac operation performed through a median sternotomy both before and after pectus repair, and the remaining patient, early in the series, had simultaneous banding of the main pulmonary artery and repair of pectus excavatum complicated by chest wall instability and a lethal intrathoracic hemorrhage. The experience indicates that congenital chest wall deformities can be safely and effectively repaired after early correction of congenital heart defects through a median sternotomy, although repair of the chest wall deformity after cardiac surgery also gives good results. However, in children who require an extracardiac conduit for repair of their congenital heart defect, we recommend initial repair of the pectus excavatum followed at 6 weeks or later by repair of the cardiac lesion to eliminate possible extrinsic compression of the conduit by the depressed sternum. We avoid simultaneous cardiac and pectus excavatum repair because of potential associated major complications.     

Repair of pectus excavatum deformities: 30 years of experience with 375 patients

OBJECTIVE: To review the surgical experience with pectus excavatum chest deformities at UCLA Medical Center during a 30-year period. BACKGROUND: Pectus excavatum is a relatively common malformation that is often symptomatic; however, children's physicians often do not refer patients for surgical correction. METHODS: Hospital records from 375 patients who underwent repair of pectus excavatum deformities between 1969 and 1999 were reviewed. Decrease in stamina and endurance during exercise was reported by 67%; 32% had frequent respiratory infections, 8% had chest pain, and 7% had asthma. The mean pectus severity score (width of chest divided by distance between posterior surface of sternum and anterior surface of spine) was 4.65 (normal chest = 2.56). All patients had marked cardiac deviation into the left chest. Repair was performed with subperiosteal resection of the abnormal cartilages, transverse wedge osteotomy of the anterior sternum, and internal support with a steel strut for 6 months. Repair was performed on 177 children before age 11 years; 38 adults with severe symptoms underwent repair. RESULTS: The mean hospital stay was 3.1 days. With a mean follow-up of 12.6 years, all patients with preoperative respiratory symptoms, exercise limitation, and chest pain experienced improvement. Vital capacity increased 11% (mean) within 9 months in 35 patients evaluated. There were no deaths. Complications included hypertrophic scar formation (35), atelectasis (12), pleural effusion (13), recurrent sternal depression (5), and pericarditis (3). More than 97% had a very good or excellent result. CONCLUSION: Pectus excavatum deformities can be repaired with a low rate of complications, a short hospital stay, and excellent long-term physiologic and cosmetic results.     

Improved chest wall fixation for correction of pectus excavatum.

Pectus excavatum, the most common congenital chest wall abnormality, is manifested by deformity of the costal cartilages resulting in a depressed and often rotated sternum. Although there are conflicting data to support and reject the concept that physiologic improvement can be a consequence of surgical repair, correction is frequently indicated for aesthetic improvement alone. The most popular current repair involves resection of abnormal costal cartilages, sternal osteotomy and mobilisation, followed by fixation of the sternum in the corrected position. Improved fixation techniques have evolved, but generally have not employed current concepts of rigid fixation. The correction of pectus excavatum using reconstruction plates incorporates the benefits of rigid fixation, while allowing custom chest wall contouring and sternal reorientation. Reconstruction plate fixation of the sternum should be considered during correction of pectus excavatum in adult and adolescent patients.     

Technical considerations in the surgical management of pectus excavatum and carinatum

During the past 25 years, 650 operations have been performed on 608 patients for anatomically significant pectus excavatum or carinatum deformities of the anterior chest wall. There were no deaths in this series, and serious complications were very rare.We conclude that repair of pectus excavatum and carinatum deformities should include the following operative steps: (1) adequate mobilization of the sternum and correction of its abnormal angulation by transverse osteotomy; (2) adequate bilateral removal of the involved costal cartilage; and (3) securing the corrected position of the sternum with the patient's own living tissue, retaining its blood supply and using it as an internal support.Using these principles, new surgical procedures were developed for the correction of: symmetrical pectus excavatum, asymmetrical pectus excavatum, pectus carinatum with xiphoid angulation, pectus carinatum without xiphoid angulation, asymmetrical pectus carinatum, chondromanubrial prominence with chondrogladiolar depression, and recurrent pectus excavatum.We recommend surgical correction for patients in whom the deformity is significant and no contraindication exists. The ill effects of this condition should not be underestimated.     

Surgical correction of pectus excavatum and carinatum.

This paper contains an analysis of the long-term results in 85 patients who had pectus excavatum or carinatum deformities repaired at the North Middlesex Hospital between 1951 and 1977. Seventy-seven patients had operations for correction of pectus excavatum and eight for pectus carinatum. A variety of surgical techniques was used. In the excavatum deformities the best results were obtained by the extensive resection of all deformed cartilages, the correction of the sternal deformity by a simple transverse wedge osteotomy, and by stabilising the chest with a stainless steel plate. For pectus carinatum, the involved cartilages were resected and an osteotomy of the sternum was performed. We preferred in most cases to stabilise the chest wall with a metal strut in this deformity as well. The best cosmetic results were achieved by the use of a stainless steel plate passed beneath the sternum and left for not more than six months.     

Surgical correction of pectus carinatum

Pectus carinatum is an infrequent but eminently correctable chest wall deformity. It is encountered much less frequently than pectus excavatum. In 12 years, from 1973 to 1985, 152 pectus carinatum (16.7%) and 758 pectus excavatum deformities (83.3%) were corrected. It occurs more frequently in boys (119 patients) than girls (33 patients). The majority, 89 cases, were symmetric, while 49 were asymmetric, and 14 were mixed deformities (ipsilateral carinatum, contralateral excavatum). In almost half the patients the deformity was not identified until after the 11th birthday. A family history of chest wall deformities was present in 26%, and of scoliosis in 12%. Associated musculoskeletal abnormalities were identified in 34 patients (scoliosis 23, Poland's syndrome 4, neurofibromatosis 2, Morquio's disease 2, vertebral anomalies 1, hyperlordosis 1, and kyphosis 1). Surgical correction required bilateral resection of the third through seventh costal cartilages in 143 patients, and unilateral resection in nine patients with an isolated abnormality. A single osteotomy was used in 88 patients and a double osteotomy in 53 patients. In 11 cases no osteotomy was required. Mixed deformity with posterior angulation of the sternum was managed by osteotomy and anterior displacement. The remaining cases had sternal osteotomy and fracture of the posterior cortex to correct anterior angulation. The operation was completed with a low complication rate 3.9% (pneumothorax 4, wound infection 1, atelectasis 1, and local tissue necrosis 1). Three patients required revision with additional unilateral lower cartilage resection for persistent malformation of the costal arch. All patients ultimately had a satisfactory result.     

Scoliosis in children with pectus excavatum and pectus carinatum

Between 1974 and 1985, 461 patients with pectus excavatum and 135 patients with pectus carinatum underwent operative repair of their anterior chest wall deformities. Twenty-one percent of patients with anterior chest wall deformity had mild scoliosis by clinical and radiographic examination. The average lateral spinal deformity was 15 degrees (range 6-78 degrees) for pectus excavatum patients and 16 degrees (range 5-57 degrees) for pectus carinatum patients. Eighteen percent of the pectus excavatum patients with scoliosis and 14% of the pectus carinatum patients with scoliosis required therapeutic intervention of bracing and/or arthrodesis.     

Coronary artery bypass via resternotomy after pectus excavatum repair

Pectus excavatum is a chest wall deformity that commonly warrants pediatric surgical correction for cosmesis or respiratory impairment via sternotomy. The repair typically consists of sternal wedge osteotomy and subsequent placement of a Steinman pin across the sternum with fixation to the ribs bilaterally. Coronary artery bypass grafting (CABG) after surgical repair of the sternum with a metal implant poses an intriguing surgical challenge. Literature review reveals only one such previously described case. We present a case of coronary revascularization in an adult who previously underwent pectus excavatum repair with ligation of the internal mammary arteries. Our coronary revascularization was accessed through a resternotomy after surgical removal of the metal implant previously placed during the pectus excavatum repair. Autologous greater saphenous vein was used as a conduit for bypass. The patient did well postoperatively and was discharged on postoperative day 4. The pectus repair remained intact even after the median sternotomy was performed. This was confirmed at the 1-year follow-up for the patient. Resternotomy after pectus excavatum repair with a prosthetic implant poses a challenge to cardiothoracic surgeons. Many such repairs have been described in the pediatric population. As our society ages and coronary artery disease becomes more prevalent, this unique situation may be more commonly encountered. We present an approach to coronary artery bypass grafting via median resternotomy after pectus excavatum repair.     

Long-term observation in 68 patients operated on for pectus excavatum: surgical repair of funnel chest

BACKGROUND: Recurrence after correction of pectus excavatum may sometimes occur, but its origin is not clear. The type of deformity, surgical technique, and patient lifestyle after operation can all affect the final shape of the thorax. The purpose of the present study was to compare the short-, medium-, and long-term cosmetic results of funnel chest repair. METHODS: Sixty-eight patients (mean age, 12.1+/-5.4 years; 48 male) were operated on for pectus excavatum using the same surgical technique: subperichondrial resection of the abnormal costal cartilages and stabilization of the elevated anterior chest wall with Kirschner's wires. The patients were followed up every year (1 to 10 years) after operation, and the anterior chest wall contour was checked by physical examination and x-ray film. RESULTS: Excellent to good cosmetic results 1 year after operation were achieved in 66 patients (97.1%). During the later follow-up period, a mild or moderate degree of recurrent sternal depression was noted in 6 patients (8.8%), teenagers only, 3 to 9 years after primary repair. CONCLUSIONS: Our technique for correction of pectus excavatum yields good short-term cosmetic results. Late recurrence of the deformity occurs during pubertal growth and does not appear to depend on surgical technique or length of follow-up.     

Open repair of pectus excavatum with minimal cartilage resection

OBJECTIVE: To summarize the clinical experience with a new open repair for pectus excavatum (PE), with minimal cartilage resection. SUMMARY BACKGROUND DATA: A wide variety of modified techniques of the Ravitch repair for PE have been used over the past 5 decades, with the complications and results being inconsistent. Extensive subperiosteal costal cartilage resection and perichondrial sheath detachment from the sternum may not be necessary for optimal repair. METHODS: During a 12-month period, 75 consecutive patients with symptomatic PE underwent open repair using a new less invasive technique. After exposing the deformed costal cartilages, a short chip was resected medially adjacent to the sternum and laterally at the level where the chest had a near normal contour, allowing the cartilage to be elevated to the desired level with minimal force. A transverse anterior sternal osteotomy was used on most patients. A substernal support strut was used for 66 patients; the strut was placed anterior to the sternum in 9 patients under age 12 and over age 40 years. The strut was routinely removed within 6 months. RESULTS: With a mean follow-up of 8.2 months, all but 1 patient regarded the results as very good or excellent. Mean operating time was 174 minutes; mean hospitalization was 2.7 days. There were no major complications or deaths. CONCLUSIONS: The open repair using minimal cartilage resection is effective for all variations of PE in patients of all ages, uses short operating time, provides a stable early postoperative chest wall, causes only mild postoperative pain, and produces good physiologic and cosmetic results.     

Reactive pectus carinatum in patients treated for pectus excavatum

Purpose

The Ravitch and minimally invasive Nuss procedures have brought widespread relief to children with pectus excavatum, chest wall deformities, over the last half century. Generally accepted long-term complications of pectus excavatum repair are typically limited to recurrence of the excavatum deformity or persistent pain. This study examines the authors' experience with patients who develop a subsequent carinatum deformity within 1 year of pectus excavatum repair.

Methods

The authors retrospectively assessed the charts of all patients diagnosed as having a carinatum deformity subsequent to treatment for pectus excavatum at a tertiary urban hospital. We noted age at original correction of pectus excavatum, time from original correction to diagnosis of carinatum deformity, age at correction of carinatum deformity, complaints before correction, methods of repair, postoperative complications, and we reviewed relevant radiography.

Results

Three patients who underwent pectus excavatum repair between January 2000 and August 2007 developed a subsequent carinatum deformity. Two patients initially underwent minimally invasive Nuss correction of pectus excavatum; 1 patient underwent the Ravitch procedure. Within 1 year of original correction and despite intraoperative achievement of neutral sternal position, a protruding anterior chest deformity resembling de novo pectus carinatum emerged in each patient; we term this condition reactive pectus carinatum. The mean age of patients undergoing initial pectus excavatum repair was 13 years (range, 11-16 years). The pathophysiology of this reactive lesion is not well understood but is thought to originate from reactive fibroblastic stimulation as a result of sternal manipulation and bar placement. Patients who underwent Nuss correction initially were managed with early bar removal. Two of the patients eventually required surgical resection of the carinatum deformity at a time interval of 3 to 6 years after initial excavatum repair. In one patient, the carinatum deformity resolved spontaneously. Neutral chest position and absence of dyspenic symptoms were achieved in all patients.

Conclusions

Reactive pectus carinatum is functionally encumbering and a poor cosmetic complication of either the Ravitch or minimally invasive Nuss procedures. Our experience with reactive pectus carinatum introduces the importance of postoperative vigilance even in patients without underlying fibroelastic disease. Examination of the chest with attention to the possibility of an emerging carinatum deformity, particularly in the first 6 postoperative months, is paramount. A telephone call to the patient at 3 months may be a useful adjunct to clinic visits. An optimal long-term result may be achieved through a combination of early Nuss bar removal or postpubertal pectus carinatum repair.     

Repair of pectus excavatum and carinatum deformities in 116 adults

OBJECTIVE: To determine the feasibility of surgically correcting pectus excavatum and carinatum deformities in adult patients. SUMMARY BACKGROUND DATA: Although pectus chest deformities are common, many patients progress to adulthood without surgical repair and experience increasing symptoms. There are sparse published data regarding repair of pectus deformities in adults. METHODS: Since 1987, 116 patients over the age of 18 years with pectus excavatum (n = 104) or carinatum (n = 12) deformities underwent correction using a highly modified Ravitch repair, with a temporary internal support bar. The ages ranged from 19 to 53 years (mean 30.1). Eighty-six patients sought repair after reviewing information regarding pectus deformities available on the Internet. Each patient experienced dyspnea with mild exertion and decreased endurance; 84 had chest pain with activity; 75 had palpitations and/or tachycardia. Seven patients underwent repair for symptomatic recurrent deformities. The mean severity score (chest width divided by distance from sternum to spine) was 4.8. The sternal bar was removed from 101 patients 6 months after the repair without complications. RESULTS: Each of the patients with reduced endurance or dyspnea with mild exercise experienced marked improvement within 6 months. Chest discomfort was reduced in 82 of the 84 patients. Complications included pleural effusion (n = 7), pneumothorax (n = 2), pericarditis (n = 2), dislodged sternal bar (n = 3), and mildly hypertrophic scar (n = 12). Mean hospitalization was 2.9 days; mean blood loss was 122 mL. Pain was mild and of short duration (intravenous analgesics were used a mean of 2.1 days). There were no deaths. With a mean follow-up of 4.3 years, 109 of 113 respondents had a very good or excellent result. CONCLUSIONS: Although technically more difficult than in children, pectus deformities may be repaired in adults with low morbidity, short hospital stay, and very good physiologic and cosmetic results.     

Cardiopulmonary resuscitation in patients with a Nuss bar--a case report and review of the literature

Pectus excavatum (PE) is a common chest wall deformity that may produce a variety of physiological and psychological effects in children and adolescents. In addition, some of these patients have associated cardiac diseases (ie, mitral valve prolapse and Marfan syndrome). Recently, a minimally invasive surgical repair of PE that requires sternal bar placement has become increasingly frequent to enhance patients' cardiopulmonary functioning as well as their self-esteem. However, despite this innovative technique, it is possible for such patients to have a cardiac arrest while their sternal bar is in place. Whether the presence of a metal bar on the underside of their sternum may hinder resuscitative chest compressions (cardiopulmonary resuscitation) is an issue that concerns us, our patients, and their families; the answer requires further investigation. We present a 21-year-old man with PE who underwent a minimally invasive pectus repair but had a fatal cardiac event before bar removal. Paramedics conducting cardiopulmonary resuscitation on the patient later reported that they were unable to deliver effective cardiac compressions and that the sternal bar may have contributed to this.     

A 26-year review of pectus deformity repairs, including simultaneous intracardiac repair

BACKGROUND: We reviewed our operative experience and long-term results with repair of pectus excavatum and carinatum deformities through a vertical midline approach, including those cases with simultaneous intracardiac repair. METHODS: From 1972 through 1998, 120 children underwent pectus deformity repair. Operative technique used a vertical midline incision with subperichondrial resection of deformed cartilages and an anterior sternal osteotomy. Thirty-five patients had a temporary metal bar for retrosternal support for 6 months; 85 underwent repair without a bar. Patients and parents were asked to assess the outcome after pectus repair as poor, fair, good, or excellent. RESULTS: There were 94 male and 26 female patients (mean age, 8.4 years; range, 3 to 21 years). There were 111 cases of pectus excavatum and 9 of pectus carinatum. Fourteen children (11.5%) had an associated congenital heart defect; 9 patients had simultaneous pectus and intracardiac repair. One patient was referred for emergent open heart repair and pectus repair after attempted "Nuss" repair resulted in a perforated right atrium, perforated right ventricle, and partially disrupted tricuspid valve apparatus. There were no deaths and only one significant complication, which required a return to the operating room for bleeding. Morbidity was not higher in patients with simultaneous intracardiac repair. Long-term follow-up was established in 83% of patients. Results were classified as excellent in 64 patients (64%), good in 25 (25%), fair in 8 (8%), and poor in 3 (3%). Thirty (86%) of 35 patients with a sternal bar had excellent results versus 34 (52%) of 65 without a bar (p = 0.004); 97% of patients who underwent repair with a sternal bar classified the result as excellent or good. CONCLUSIONS: Long-term results of pectus excavatum and carinatum repair through a vertical midline approach are excellent. Outcome with a temporary sternal bar is superior to outcome without a bar. Concomitant repair of congenital heart defects and pectus deformity may be performed successfully without additional morbidity.     

改良胸骨上举术治疗漏斗胸

目的探讨改良胸骨上举术治疗漏斗胸以取得操作简便、创伤小、不易复发的手术方法。方法通过松解剑突后牵拉纤维束、矫正胸肋软骨反向关节畸形、胸骨前板V形截骨钢丝固定、斜形切除部分软骨牵拉固定等改进胸骨上举术方法治疗漏斗胸。结果1997年3月以来，治疗8例漏斗胸患儿，其中4例术前心率快者术中解除胸骨压迫后心率立即减缓。术中出血少，术后胸部形态恢复正常，活动能力明显改善。未出现气胸、感染等并发症。随访6个月～1年，未见畸形复发。结论改良胸骨上举术治疗漏斗胸畸形是安全有效的治疗方法。     

Repair of pectus excavatum and carinatum in adults

BACKGROUND: There is sparse published information regarding the repair of pectus chest deformities in adults. This report summarizes our clinical experience with the surgical repair of pectus excavatum and carinatum deformities in 25 adults. METHODS: During the past 11 years, 25 patients 20 years of age or older (mean 31) with symptomatic pectus excavatum (23) or carinatum (2) deformities underwent surgical repair using a temporary internal sternal support bar. RESULTS: Each of the patients with decreased stamina and endurance or dyspnea with exercise experienced marked clinical improvement within 4 months postoperation. Exercise-induced asthma was improved in 6 of 7 patients; chest pain was reduced in each of 9 patients. Postoperative complications included pneumothorax (1), keloid (2), and discomfort from sternal bar (2). The sternal bar was removed 7 to 10 months postoperation in 19 patients; there has been no return of preoperative symptoms or recurrent depression in any patient with a mean follow-up of 4.8 years. CONCLUSIONS: For adults who have symptoms and activity limitations related to uncorrected pectus chest deformities, surgical repair can be performed with low morbidity, low cost, minimal limitation in activity, and a high frequency of symptomatic improvement. The operation in adults is more difficult than in children, although the results are similar.     

Simultaneous repair of cardiovascular disorders and pectus deformity in a patient with Sprintzen-Goldberg syndrome: A case report.

We report a 12-year-old girl with Sprintzen-Goldberg syndrome (SGS) who was complicated with annuloaortic ectasia with aortic regurgitation, mitral valve prolapse with mitral regurgitation, and a severe pectus excavatum. In this patient, aortic root replacement, mitral valve replacement, and sternal elevation were simultaneously performed, and a version of Ravitch's procedure that was technically modified to support the sternum was used for sternal elevation. This modified sternal elevation technique gave excellent operative exposure, and maintained chest wall stability after the operation.