Impact of delayed removal of pectus bar on outcomes following Nuss repair: a retrospective analysis.

BACKGROUND: Usually, pectus bars are removed 3 years after the Nuss procedure in patients with pectus excavatum. However, the optimal timing for postoperative pectus bar removal remains undefined. Our study investigated the effects of delayed pectus bar removal after Nuss repairs. METHODS: Retrospective data were collected on patients who underwent Nuss procedures for pectus excavatum and had their bars removed from August 2014 to December 2020. Patients with correction periods > 3 years were divided into group A (< 6 years) and group B (≥ 6 years). Propensity score matching was used to compare complications and radiological outcomes associated with bar removal. RESULTS: Of the 542 patients who underwent bar removal, 451 (Group A: 419 patients, Group B: 32) had correction duration > 3 years. The average correction duration was 4.5 ± 1.4 years. After propensity score matching analysis, group B [median duration: 8.0 (6.0-16.2) years] exhibited significantly longer median operative times (85 vs. 55 min; P = 0.026), higher callus formation rates (68.8% vs. 46.9%; P = 0.029), and greater median intraoperative blood loss (35 vs. 10 mL; P = 0.017) than group A [median duration: 4.2 (3.0-5.9) years]. However, following bar removal, the groups showed no statistical differences in the surgical complication rates (group A: 6.3% vs. group B: 9.4%; P = 0.648) or median ratio of radiological improvement (an improvement on the Haller index on chest radiography; 21.0% vs. 22.2%; P = 0.308). CONCLUSIONS: Delaying pectus bar removal after Nuss repair presents certain challenges but does not compromise overall outcomes. These findings suggest that a longer correction period may be unnecessary. However, further multicenter studies with long-term follow-up are warranted to assess long-term outcomes.

Body measurement changes in adults with pectus excavatum after the Nuss procedure: a study of 272 patients.

BACKGROUND: Pectus excavatum (PE) is the most common congenital abnormality of the chest wall. Most patients with PE have slim bodies. Some studies have been conducted on the physical growth of children and adolescents who underwent the Nuss procedure. This study aimed to evaluate body measurement changes in adult patients with PE after the Nuss procedure. METHODS: A total of 272 adult PE patients, who underwent the Nuss procedure and pectus bars removal from August 2014 to December 2020, were evaluated retrospectively. Body measurement [body height (BH), body weight (BW), and body mass index (BMI)] of the patients were collected before Nuss repair and after bar removal. We used the interquartile range (IQR) to identify and exclude outliers. Associations between changes in body measurement and clinical and radiological features were evaluated. RESULTS: The BH, BW and BMI showed significantly increased after pectus bar removal, compared to pre-Nuss procedure parameters (BH 173.8 ± 5.9 cm vs. 173.9 ± 5.9 cm, P < 0.001; BW 60.3 ± 8.1 kg vs. 61.1 ± 8.8 kg, P = 0.005; BMI 19.9 ± 2.2 kg/m2 vs. 20.1 ± 2.4 kg/m2, P = 0.02). The same result were observed in the male subgroup, the HI ≥ 4 group and the male subgroup within the HI ≥ 4 group. CONCLUSIONS: The BH, BW and BMI were significantly increased after completing surgical correction of PE using the Nuss procedure, particularly in young males and patients with more pronounced deformities.

Machine Learning: Using Xception, a Deep Convolutional Neural Network Architecture, to Implement Pectus Excavatum Diagnostic Tool from Frontal-View Chest X-rays.

Pectus excavatum (PE), a chest-wall deformity that can compromise cardiopulmonary function, cannot be detected by a radiologist through frontal chest radiography without a lateral view or chest computed tomography. This study aims to train a convolutional neural network (CNN), a deep learning architecture with powerful image processing ability, for PE screening through frontal chest radiography, which is the most common imaging test in current hospital practice. Posteroanterior-view chest images of PE and normal patients were collected from our hospital to build the database. Among them, 80% were used as the training set used to train the established CNN algorithm, Xception, whereas the remaining 20% were a test set for model performance evaluation. The performance of our diagnostic artificial intelligence model ranged between 0.976-1 under the receiver operating characteristic curve. The test accuracy of the model reached 0.989, and the sensitivity and specificity were 96.66 and 96.64, respectively. Our study is the first to prove that a CNN can be trained as a diagnostic tool for PE using frontal chest X-rays, which is not possible by the human eye. It offers a convenient way to screen potential candidates for the surgical repair of PE, primarily using available image examinations.

Co-existing obstructive sleep apnea reduces Nuss surgery efficacy in pectus excavatum.

Nuss surgery is effective in correcting pectus excavatum (PE), with a recurrence rate of 1.2-27%. Re-do surgery is successful but still has a 6% failure rate. Patients with obstructive sleep apnea (OSA) experience repetitive PE-associated sternal depression during sleep. As the prevalence of OSA among PE patients is higher than the average, co-existing OSA in PE patients might negatively affect the efficacy of Nuss surgery. This study aimed to evaluate the impact of co-existing OSA on Nuss surgery in patients with PE. In total, 20 adult patients with PE only and 9 patients with PE and OSA were analyzed. Polysomnography was performed before Nuss surgery to evaluate OSA. Sternovertebral distance (SVD) and radiographic Haller index (RHI) were recorded before surgery and at 3, 6, and 24 months postoperatively. The results showed that percentage changes in SVD in patients with PE only at 3, 6, and 24 months postoperatively were significantly increased compared with those in the patients with PE and OSA (31.1% vs. 14.1% at 3 months; 37.5% vs. 21.4% at 6 months; 42.5% vs. 19.2% at 24 months). Meanwhile, percentage changes in RHI were significantly lower in patients with PE alone than in the patients with PE and OSA (-22.9% vs. -9.3% at 3 months; -27.9% vs. -18.7% at 6 months; -30.6% vs. -16.7% at 24 months). This study showed that co-existing OSA might reduce the efficacy of Nuss surgery for patients with PE. We recommend that patients with PE should be evaluated and treated for OSA before surgery to prevent surgical failure after bar removal.

Autonomic nervous system dysregulation in response to postural change in patients with pectus excavatum in Taiwan: a pilot study.

BACKGROUND: Pectus excavatum (PE) negatively impacts psychological function, but its effect on autonomic nervous system (ANS) function has not been investigated. We evaluated ANS function following postural changes in patients with PE. METHODS: The participants were 14 healthy men (control group) and 20 men with PE (study group). Psychological function was assessed using the visual analog scale for pain, Brief Symptom Rating Scale-5, and Beck Depression Inventory-II. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). ANS regulation in response to postural change was measured in the supine position and immediately after sitting. All measurements were compared between the control and study groups at baseline and between the study groups before and after Nuss surgery. RESULTS: At baseline, upon postural change, symptomatic activity increased in the control group (50.3-67.4%, p = 0.035) but not in the study group (55.0-54.9%, p = 0.654); parasympathetic activity decreased in the control group (49.7-32.6%, p = 0.035) but not in the study group (45.1-45.1%, p = 0.654); and overall ANS regulation increased in the control group (1.02-2.08, p = 0.030) but not in the study group (1.22-1.22, p = 0.322). In response to postural change after Nuss surgery in the study group, sympathetic activity increased (48.7-70.2%, p = 0.005), parasympathetic activity decreased (51.3-29.8%, p = 0.005), and overall ANS regulation increased (0.95-2.36, p = 0.012). CONCLUSION: ANS function in response to postural change is dysregulated in patients with PE, which improved after Nuss surgery. Trial registration ClinicalTrials.gov, ID: NCT03346876, November 15, 2017, retrospectively registered, https://register. CLINICALTRIALS: gov/prs/app/action/SelectProtocol?sid=S0007KGI&selectaction=Edit&uid=U0003JZU&ts=2&cx=cstxeg.

A retrospective study on the impact of bar flipping on the recurrence of pectus excavatum after the Nuss procedure.

BACKGROUND: The Nuss procedure is widely used to correct pectus excavatum. Bar displacement is a common complication associated with this procedure. How the flipping of the bar affects pectus excavatum recurrence has not been reported. In our study, we discuss this and also offer an easier method to determine bar flipping. METHODS: This retrospective study analyzed pectus excavatum patients who underwent primary Nuss repair from August 2014 to December 2018. The preoperative and postoperative Haller indices were measured on chest radiographs (cxrHI). The slope angle of bar flipping (α) was measured on lateral chest radiographs. The improvement index after surgical repair was calculated by: ([preoperative cxrHI-postoperative cxrHI]/preoperative cxrHI × 100). The impact of α on the improvement index was analyzed using one-way analysis of variance and receiver operating characteristic tests. RESULTS: In this study, 359 adult and adolescent patients with an average age of 23.9 ± 7.7 years were included. We formed four subgroups based on the α value: α ≤ 10° (n = 131), α = 11-20° (n = 154), α = 21-30° (n = 51), and α > 30° (n = 23). The mean improvement indices in these groups were 27%, 28%, 26%, and 13%, respectively. Patients with α > 30° were associated with a significantly poorer improvement index than those from the other subgroups (p < 0.001). CONCLUSIONS: The α value is an alternative measurement method for presenting the radiological outcomes after the Nuss procedure. An α > 30° indicates a possible recurrence of pectus excavatum after the Nuss repair. Surgical revision may be considered in patients with an α > 30°, while monitoring should be considered in the other patient groups.

The Nuss procedure for pectus excavatum: An effective and safe approach using bilateral thoracoscopy and a selective approach to use multiple bars in 296 adolescent and adult patients.

The Nuss procedure is a minimally invasive repair used to treat pectus excavatum. A bilateral thoracoscopy-assisted approach has been reported as a safe method for Nuss repair. The aim of this observational cohort study is to evaluate the application of the bilateral thoracoscopy-inspection to assist in the selection of the number of bars for correction of the pectus deformity in adolescents and adults. A retrospective chart review was performed on all adolescent and adult patients (296 patients: 257 male, 39 female; aged of 23.9 ± 7.7 years) with pectus excavatum primarily corrected with the modified Nuss repair from August 2014 to January 2018. The patients were divided into three age groups (A: 12 years ≦ age < 19 years, n = 73; B: 19 years ≦ age < 30 years, n = 175; C: age ≧ 30 years, n = 48). Advanced repair of deformed chest walls using more than one bar depended on the change detected via gross and perioperative thoracoscopy-inspection. The results showed that two or three pectus bars were used in 268 patients (90.5%). The overall complication rate after a postoperative follow-up of 28.6 ± 11 months was 6.8% (20/296), without mortality, major bleeding, or serious infectious complications. A multivariate logistic regression analysis showed that the complications were only associated with Haller index (adjusted OR = 1.2935, p = 0.0317) under controlling confounding factors. The postoperative sternovertebral distance was significantly improved from 7.3±1.6 to 10.1± 2.8 cm (p<0.001). The thoracoscopy-assisted approach of Nuss repair for correction of pectus excavatum was safe and effective approach and could also be used as an alternative approach for the selection of placed bars in adolescent and adult patients. Further studies regarding long-term outcomes are required.

Minimization of the complications associated with bar removal after the Nuss procedure in adults.

BACKGROUND: Pectus bar removal after Nuss repair is associated with the risk of major complications that are underreported. Of these, surgical bleeding is the main concern. Old age and placement of more than one bar are reported risk factors for pectus bar removal. In this study, we presented our experience regarding the modified skills required to minimize complications during bar removal, especially in adult patients. METHODS: Consecutive patients who underwent pectus bar removal as the final stage of Nuss repair between August 2014 and December 2018 were included. The patients were positioned in the supine position. The bar(s) was (were) removed from the left side via the bilateral approach using the previous surgical scars after full dissection of the ends of the bar lateral to the hinge point and after straightening the right end of the bar. Bleeding was carefully checked after removal. An elastic bandage was wrapped around the chest after wound closure to prevent wound hematoma/seroma formation. RESULTS: A total of 283 patients (260 male and 23 female), with a mean age of 22.8 ± 6.6 years at the time of the Nuss repair were included. The mean duration of pectus bar maintenance interval was 4.3 years (range: 1.9 to 9.8 years). A total of 200 patients (71%) had two bars. The mean estimated blood loss was 11.7 mL (range: 10 mL to 100 mL). Nine patients (3.1%) experienced complications, six had pneumothorax and three had wound hematoma. No major bleeding occurred. Adults and the use of more than one bar were not associated with a significantly higher rate of complications (P = 0.400 and P = 0.260, respectively). CONCLUSIONS: Adult patients and removal of multiple bars were not risk factors for complications in our cohort. Skill in preventing intraoperative mediastinal traction, carefully controlling bleeding, and reducing the effect of dead space around the wounds could minimize the risk of bleeding complications. A multicentric study or case accumulation is needed to further evaluate the risk factors of removal pectus bar(s).

Improved Dynamics of Thoracic Cage and Exercise Capacity after Nuss Repair for Pectus Excavatum.

BACKGROUND: Pectus excavatum (PE) reduces the dynamics of the thoracic cage, with a negative impact on exercise capacity. We aimed to evaluate the effects of Nuss repair for PE on the dynamics of the thoracic cage and exercise capacity in adults. METHODS: This was a prospective observational study of 46 adults (mean age, 26.2 years) who underwent PE correction using the Nuss procedure between September 2016 and August 2017. Cirtometry was used to obtain measures of thoracic cage circumference at two levels (axillary level [AL] and xyphoid level [XL]), at the end points of inspiration and expiration. Circumference measures were obtained before surgery and at 1, 3, and 6 months after surgery. Exercise capacity was also evaluated using the 6-minute walk test (6MWT). The association between the 6MWT data and cirtometry measures was evaluated using Pearson's correlation. RESULTS: The circumference at maximum inspiration increased from baseline to 3 months after surgery (p < 0.01), at both the AL (84.5 ± 4.9 vs. 88.5 ± 5.1 cm) and XL (80.1 ± 4.8 vs. 83.7 ± 5.1 cm). The 6MWT also significantly improved from baseline to 3 months after surgical correction (544.7 ± 64.1 vs. 637.3 ± 59.4 m, p < 0.01), with this improvement being correlated to the increase in thoracic circumference on maximal inspiration at both the AL and XL (0.8424 and 0.7951, respectively). CONCLUSION: Improved dynamics of the thoracic cage were achieved after Nuss repair for PE in adults. This increase in thoracic circumference at maximum inspiration was associated with an improvement in exercise capacity at 3 months after surgery.

Improvement in Polysomnographic Objective Sleep Quality in Adults with Pectus Excavatum After the Nuss Procedure.

BACKGROUND: Patients with pectus excavatum have a poorer subjective sleep quality and quality of life than the general population. The Nuss procedure has been shown to improve these patients' quality of life, but data regarding their postoperative sleep quality are lacking. We aimed to evaluate the objective sleep quality of adults with pectus excavatum before and after the Nuss procedure. METHODS: Twenty-eight participants completed this study. Epworth Sleepiness Scale (ESS) scores for daytime sleepiness, Pittsburgh Sleep Quality Index (PSQI) scores for subjective sleep quality, and overnight polysomnography for objective sleep quality were evaluated before and 6 months after the Nuss procedure. RESULTS: Subjective sleep quality improved after the Nuss procedure. The median PSQI score decreased from 7 [interquartile range (IQR): 5; 9] to 5 (IQR: 4; 7, p = 0.029); the median percentage of poor PSQI sleep quality decreased from 64.3 to 35.7% (p = 0.048). The median percentage of rapid eye movement sleep significantly increased after surgery [15.6% (IQR: 12.2%; 19.8%) vs. 20.4% (IQR: 14.5%; 24.9%), p = 0.016]. Sleep interruptions also improved, with the median arousal index decreasing from 9.5 (IQR: 4.8; 18.2) to 8.2 (IQR: 4.3; 12.1; p = 0.045). However, there was no significant change in ESS scores after surgery (p = 0.955). CONCLUSIONS: Pectus excavatum may be associated with poor subjective and objective sleep quality in adults, and the condition may improve after the Nuss procedure. For adults with pectus excavatum who report poor subjective sleep quality, polysomnography should be considered to assess their preoperative and postoperative sleep condition.

Poorer sleep quality among adult patients with pectus excavatum in Taiwan: A pilot study.

OBJECTIVES: Patients with pectus excavatum have a poorer quality of life than the general population. Sleep quality is a critical component of quality of life. This pilot study compared the sleep quality of adult patients with pectus excavatum with that of the general population in Taiwan. METHODS: Participants comprised 30 healthy adults, 21 adult outpatients with pectus excavatum, and 33 adults with pectus excavatum receiving Nuss surgery. The Pittsburgh Sleep Quality Index measured subjective sleep quality; the Visual Analog Scale for Pain, Brief Symptom Rating Scale-5, Beck Depression Inventory II, and 36-Item Short Form Survey measured quality of life; and the Epworth Sleepiness Scale measured excessive daytime sleepiness. Outcome measurements were obtained at baseline for all groups and 6 months after Nuss surgery for inpatients. RESULTS: Patients with pectus excavatum had poorer sleep quality and worse quality of life than controls. Poorer sleep quality was not related to the severity of pectus excavatum per se, but to psychologic issues (beta = 0.18, P < .001 in multiple linear regression analysis). Measurement time had no effect on sleep quality (beta = 0.31, P = .594 for outpatient group; beta = 0.27, P = .665 for inpatients). Sleep quality of patients with pectus excavatum improved after Nuss surgery (Pittsburgh Sleep Quality Index: 4 vs 7, P = .002). CONCLUSIONS: Our findings suggested an association between poor sleep quality and pectus excavatum; thus, sleep quality should be evaluated before and after the Nuss procedure.

Increased prevalence of obstructive sleep apnea in patients with pectus excavatum: A pilot study.

OBJECTIVE: Laryngomalacia is the most common congenital laryngeal anomaly and is associated with pectus excavatum (PE). Patients with laryngomalacia and patients with obstructive sleep apnea (OSA) both experience upper airway obstruction, and patients with laryngomalacia had been found to have a higher prevalence of PE. However, no studies have established the prevalence of OSA in patients with PE. We conducted this pilot study to evaluate the prevalence of OSA in patients with PE. MATERIALS AND METHODS: A total of 42 patients ≥20 years old with PE who were admitted for Nuss surgery to correct PE in Taipei Tzu Chi Hospital between October 2015 and September 2016 were invited to participate in the study; 31 of the 42 patients agreed. All 31 patients completed an Epworth sleepiness scale questionnaire to evaluate excessive daytime sleepiness (EDS) and underwent overnight polysomnography to evaluate OSA before Nuss surgery. RESULTS: The prevalence of snoring in the study participants was 100%. Ten of 31 patients (32.3%) reported EDS. The overall prevalence of OSA with an apnea/hypopnea index ≥5/h was 25.8%, and all patients with OSA were men. CONCLUSIONS: The prevalence of OSA in patients with PE seemed to be higher than that previously reported in the general population, implying that OSA might be a potential etiology or, at least, an aggravating factor for the development or progression of PE or might be responsible for the postoperative recurrence of PE in some patients. Further studies are needed to clarify this relationship.

Molecular Regulation of Bone Metastasis Pathogenesis.

Distant metastases are the major cause of mortality in cancer patients. Bone metastases may cause bone fractures, local pain, hypercalcemia, bone marrow aplasia, and spinal cord compression. Therefore, the management of bone metastases is important in cancer treatment. Normal bone remodeling is regulated by osteoprotegerin ligand (OPGL), receptor activator of NF-κB ligand (RANKL), parathyroid hormone-related protein (PTHrP), and other cytokines. In the tumor microenvironment, tumor cells induce a vicious cycle that promotes osteoblastic and osteolytic lesions. Studies support the idea that distant metastases may occur due to the immunosuppressive function of myeloid-derived suppressor cells (MDSCs). These cells inhibit T cells and natural killer (NK) cells and differentiate into tumor-associating macrophages (TAMs), monocytes, and dendritic cells (DCs). In this review, we summarize studies focusing on the role of MDSCs in bone metastasis and provide a strong foundation for developing anticancer immune treatments and anticancer therapies, in general.

Current Mechanistic Concepts in Ischemia and Reperfusion Injury.

Ischemia-reperfusion injury is associated with serious clinical manifestations, including myocardial hibernation, acute heart failure, cerebral dysfunction, gastrointestinal dysfunction, systemic inflammatory response syndrome, and multiple organ dysfunction syndrome. Ischemia-reperfusion injury is a critical medical condition that poses an important therapeutic challenge for physicians. In this review article, we present recent advances focusing on the basic pathophysiology of ischemia-reperfusion injury, especially the involvement of reactive oxygen species and cell death pathways. The involvement of the NADPH oxidase system, nitric oxide synthase system, and xanthine oxidase system are also described. When the blood supply is re-established after prolonged ischemia, local inflammation and ROS production increase, leading to secondary injury. Cell damage induced by prolonged ischemia-reperfusion injury may lead to apoptosis, autophagy, necrosis, and necroptosis. We highlight the latest mechanistic insights into reperfusion-injury-induced cell death via these different processes. The interlinked signaling pathways of cell death could offer new targets for therapeutic approaches. Treatment approaches for ischemia-reperfusion injury are also reviewed. We believe that understanding the pathophysiology ischemia-reperfusion injury will enable the development of novel treatment interventions.

New Insights into the Immune Molecular Regulation of the Pathogenesis of Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome is an inflammatory disease characterized by dysfunction of pulmonary epithelial and capillary endothelial cells, infiltration of alveolar macrophages and neutrophils, cell apoptosis, necroptosis, NETosis, and fibrosis. Inflammatory responses have key effects on every phase of acute respiratory distress syndrome. The severe inflammatory cascades impaired the regulation of vascular endothelial barrier and vascular permeability. Therefore, understanding the relationship between the molecular regulation of immune cells and the pulmonary microenvironment is critical for disease management. This article reviews the current clinical and basic research on the pathogenesis of acute respiratory distress syndrome, including information on the microenvironment, vascular endothelial barrier and immune mechanisms, to offer a strong foundation for developing therapeutic interventions.

Delayed massive hemothorax complicating simple rib fracture associated with diaphragmatic injury.

Traumatic hemothorax is potentially life threatening. Rib fractures are the commonest injury after chest trauma, which accounts for 10% of patients after trauma. A delayed massive hemothorax after simple rib fracture is rare. The possibility of delayed sequelae after chest trauma should be considered, and patients should be informed of this possibility. We present a case of this uncommon situation with delayed massive hemothorax caused by simple fracture of the lower ribs. Admission should be considered for close observation when presenting with fracture of the lower ribs because of the possibility of diaphragmatic injury or intra-abdominal injury, even if a simple rib fracture is found initially.

Complex regional pain syndrome following the Nuss procedure for severe pectus excavatum.

Complex regional pain syndrome (CRPS) is not an uncommon complication after surgery, but has never been reported after the Nuss procedure for repairing pectus excavatum. A 22-year-old man with pectus excavatum had type I CRPS that developed 2 weeks after the Nuss procedure. He complained of persistent pain, hyperalgesia, weakness, edema, and color and temperature changes on right upper extremity. Following intensive rehabilitation, the degree of pain, weakness and edema were ameliorated. He recovered 6 months after surgery and the pectus bars were removed uneventfully 3 years after the repair.

Pleural effusion complicating after Nuss procedure for pectus excavatum.

PURPOSE: The Nuss procedure is a minimally invasive method for the correction of pectus excavatum (PE). Pleural effusion complicating following the Nuss procedure was uncommon but may be critical. We evaluated the risk factors of postoperative pleural effusion after Nuss repair. METHODS: We included all patients with PE primarily corrected by Nuss procedure from July 2005 to December 2011. The clinical features, treatment and outcomes of these patients with pleural effusion were analyzed retrospectively. RESULTS: 390 patients (338 men, 52 women) with a mean age of 23.9 years (5-44 years) were included. Postoperative pleural effusion occurred in 10 patients (2.6%). The time of occurrence of pleural effusion was on a mean of 16.6 days (8-32 days) after operation presenting with progressive dyspnea. All of these patients were adults, and 9 patients (90%) were repaired by two pectus bars (p <0.001). Six patients with massive pleural effusion received thoracocentesis (400 ml-1000 ml). All of the effusions were exudative. These patients took short-term indomethacin or steroids without removal of bars and all recovered well after a mean of 40 months (12-72 months) follow-up. CONCLUSIONS: Pleural effusion complicating after Nuss procedure was uncommon. It occurred most on adult patients with placement of double bars. Close follow-up in adults after more than one bar insertion is recommended. Administration of temporary medications of indomethacin/steroid and/or thoracocentesis could obtain a satisfying result. Early administration of indomethacin/steroid in adult patients repaired by two bars with mild pleural effusion for preventing pooling of effusion could also be considered.