New Computerized Planning Algorithm and Clinical Testing of Optimized Nuss Bar Design for Patients with Pectus Excavatum

BACKGROUND Computer-aided design (CAD) has been used in the Nuss procedure to determine the bar length and shape. Despite computer aid, the shape and design remain quite intuitive. We tested a new algorithm to determine the optimal bar shape. MATERIAL AND METHODS The normal sterno-vertebral distance was defined on computed tomography (CT) scans of patients without pectus excavatum (PEx) at the same level where the deepest depression was found on CT scans of 97 patients with PEx. Four points were marked on the CT scan of 60 patients with PEx at the deepest deformity: P1: edge of the vertebra; P2: edge of the deformity; P3: the expected contact point of the bar and the rib; and P4: the expected end of the bar. The algorithm generated 3 circles upon these points, and the fusion of the arcs drew the line of the ideal bar. Corrected and normal sterno-vertebral distance values were compared with the Mann-Whitney U test. Ten bars were bent manually guided by a 1: 1 printout of the designed bar and were implanted in 10 adolescents. RESULTS The shortest sterno-vertebral distance was 3 cm below the intermammillary line in PEx patients. The normal mean sterno-vertebral distance at this level was 10.16±1.35 cm in non-PEx patients. The mean virtually corrected sterno-vertebral distance was 10.28±1.27 cm. No significant difference was found (P=0.44). The bars were seamless and were successfully implanted. No bar needed adjustment, the operation time was shorter, and the patient satisfaction score was 9.4/10. CONCLUSIONS With our new algorithm, an optimal Nuss bar can be designed.

A preliminary study on the normal values of the thoracic Haller index in children

OBJECTIVES

The Haller index (HI) is widely utilized as a quantitative indicator to assess the extent of the pectus excavatum (PE) deformity, which is the most common chest wall abnormality in children. Both preoperative correction planning and postoperative follow-up need to be based on the standard of normal thoracic growth and development. However, there is currently no established reference range for the HI in children. Consequently, the goal of this study was to conduct a preliminary investigation of normal HI values among children to understand thoracic developmental characteristics.

METHODS

Chest computed tomography images obtained from January 2012 to March 2022 were randomly selected from the imaging system of the Children's Hospital of Chongqing Medical University. We divided the images of children into a total of 19 groups: aged 0-3 months (1 group), 4-12 months (1 group) and 1 year to 17 years (17 groups), with 50 males and 50 females, totaling 100 children in each group. HI was measured in the plane where the lowest point of the anterior thoracic wall was located and statistically analysed using SPSS 26.0 software.

RESULTS

A total of 1900 patients were included in the study. Our results showed that HI, transverse diameter and anterior-posterior diameter were positively correlated with age (P < 0.05). Using age as the independent variable and HI as the dependent variable, the best-fit regression equations were HI-male = 2.047 * Age0.054(R2 = 0.276, P<0.0001) and HI-female = 2.045 * Age0.067(R2 = 0.398, P<0.0001). Males had significantly larger thoracic diameters than females, and there was little difference in the HI between the 2 sexes.

CONCLUSIONS

The HI rapidly increases during the neonatal period, slowly increases during infancy and stops increasing during puberty, with no significant differences between the sexes.

Sternal cleft and pectus excavatum: an overlooked congenital association?

BACKGROUND

Sternal cleft (SC), a rare thoracic malformation, is associated with pectus excavatum (PE) in 2.6-5% of cases. It remains unclear if these conditions are congenitally linked or if SC repair triggers PE. To investigate the potential higher frequency of PE in SC cases, we conducted a retrospective study of our SC patients.

METHODS

We assessed PE incidence, progression, and management in SC patients treated at our institute from 2006 to 2022. When available, we collected pre-SC repair CT scan data, calculating the Haller Index (HI) and Correction Index (CI) and compared them to a selected control group.

RESULTS

Among 8 SC patients, 7 had concomitant PE (87.5%), varying in severity. PE management ranged from observation to thoracoplasty, depending on its degree. We observed a significant pre-operative CI difference between SC and control group patients (p < 0.00001). In the last two SC repair cases, we attempted concurrent PE prevention or treatment.

CONCLUSION

Our findings suggest an underestimated association between PE and SC in the existing literature. SC patients may exhibit a predisposition to PE from birth, which may become more apparent with growth after SC repair. Consequently, PE prevention or treatment should be considered during SC repair procedures.

Evaluating Skeletal Maturity at Time of Surgical Correction of Pectus Excavatum Based on Medial Clavicle Epiphyseal Ossification

BACKGROUND

Surgical correction of pectus excavatum (SCOPE) is dependent upon chest wall pliability with optimal timing prior to complete skeletal maturation. Measures of skeletal maturity are not readily available for operative planning; therefore, surgeons use age as proxy despite patient-specific rates of skeletal maturation. We aimed to determine whether preoperative skeletal maturity is associated with postoperative pain as surrogate for chest wall pliability.

METHODS

Children ≤18 years who underwent SCOPE from 2020 to 2022 were retrospectively identified. Preoperative CT within 3 months of procedure was reviewed by 2 radiologists and 1 surgeon. Skeletal maturity was determined by Schmeling-Kellinghaus classification which stages secondary epiphyseal ossification of the medial clavicle. Inter-rater reliability was evaluated. Schmeling-Kellinghaus stage and postoperative pain were compared.

RESULTS

Of twenty-eight records reviewed, 57% were Schmeling-Kellinghaus stage 1. High inter-rater reliability was identified (inter-radiologist: kappa = .95, P < .001, all raters: kappa = .78, P < .001). Median age at operation was 15.5 years (interquartile range: 14.8-16.0) and increased with skeletal maturity (P < .001). When comparing stage 1 (n = 16) to >1 (n = 12), stage 1 had lower maximum pain scores (P < .001), total morphine equivalents (P < .001), and benzodiazepine use (P < .001) after surgery.

CONCLUSIONS

The Schmeling-Kellinghaus classification system is a valid proxy of skeletal maturity that can be applied with high inter-rater reliability. SCOPE during stage 1 was found to have less postoperative pain and narcotic use than more mature stages. This is proof of concept that skeletal maturity should be considered when determining optimal timing of surgical correction. Future research will evaluate the impact of skeletal maturity on postoperative outcomes.

Use of Transesophageal Echocardiography for Enhanced Safety During Bar Removal Procedures After Minimally Invasive Repair of Pectus Excavatum

Background: Minimally invasive repair of pectus excavatum involves placement of retrosternal support (Nuss) bars. Hardware removal has been rarely associated with life-threatening hemorrhage from the heart, aorta, internal mammary arteries, and/or lung. There is no accepted standard intraoperative monitoring technique used during removal. We hypothesized that the use of transesophageal echocardiography (TEE) during Nuss bar removal would enhance safety of the procedure and be cost-effective. Methods: IRB-approved retrospective review of patients who underwent Nuss bar removal with intraoperative TEE monitoring over a 4-year period, from March 2013 to May 2017, was completed. Bar removal procedures were performed supine, under general anesthesia. TEE images were monitored and any distortion of the cardiac silhouette, new pericardial effusion, and/or cardiac arrhythmias would be considered evidence of possible bar adherence, triggering possible conversion to sternotomy or thoracotomy. Results: In total, 87 consecutive patients, mean age of 20 years, were identified. Bars had been in place for a mean of 30 months. Average procedure time was 67 minutes. No patients experienced arrhythmias, cardiac injury, or significant hemorrhage during removal. TEE gave excellent visualization of the cardiac silhouette and pericardium in all cases. No patient required insertion of an arterial line, a postoperative chest X-ray, or overnight hospitalization. Patients were discharged from the recovery room an average of 89 minutes postprocedure. Conclusion: TEE offers a minimally invasive safe way to visualize the pericardium and its contents during Nuss bar removal. Significant cardiac/mediastinal injuries should be immediately visible. The use of TEE is cost-effective and allows safe discharge the day of surgery.

A novel in silico Nuss procedure for pectus excavatum patients

The purpose of this study is to suggest a novel in silico Nuss procedure that can predict the results of chest wall deformity correction. Three-dimensional (3D) geometric and finite element model of the chest wall were built from the 15-year-old male adolescent patient's computed tomography (CT) image with pectus excavatum of the mild deformity. A simulation of anterior translating the metal bar (T) and a simulation of maintaining equilibrium after 180-degree rotation (RE) were performed respectively. A RE simulation using the chest wall finite element model with intercostal muscles (REM) was also performed. Finally, the quantitative results of each in silico Nuss procedure were compared with those of postoperative patient. Furthermore, various mechanical indicators were compared between simulations. This confirmed that the REM simulation results were most similar to the actual patient's results. Through two clinical indicators that can be compared with postoperative patient and mechanical indicators, the authors consider that the REM of silico Nuss procedure proposed in this study is best simulated the actual surgery.

Pectus Arcuatum: A Pectus Unlike Any Other

BACKGROUND

Pectus arcuatum is often mistaken for a type of pectus carinatum. However, pectus arcuatum is a unique clinical form of pectus caused by premature obliteration of the sternal sutures (manubrial sternum, four sternebrae and xiphoïd process), whereas pectus carinatum is due to abnormal growth of the costal cartilage. In order to better describe pectus arcuatum, we analysed the files of patients with pectus arcuatum followed in our centers.

METHODS

Multicenter retrospective study of young patients' files diagnosed with pectus arcuatum.

RESULTS

The clinical diagnosis of pectus arcuatum was made in 34 patients with a mean age at diagnosis of 10.3 years (4-23 years). A chest profile X-ray or a CT scan was performed in 16 patients (47%) and confirmed the diagnosis of PA by the presence of a sternal fusion. It was complete in 12 patients. A malformation was associated in 35% of cases (Noonan syndrome 33%, scoliosis 25% or cardiopathy 16%). 11 patients (32%) had a family history of skeletal malformation. Orthopedic treatment was initiated in 3 patients without any success. 11 patients underwent surgical correction, which was completed in 7 of them.

CONCLUSION

The diagnosis of pectus arcuatum is based on clinical experience and if necessary, on a profile chest X-ray showing the fusion of the sternal pieces. It implies the search for any associated malformations (musculoskeletal, cardiac, syndromic). Bracing treatment is useless for pectus arcuatum. Corrective surgery, based on a sternotomy associated with a partial chondro-costal resection, can be performed at the end of growth.

LEVEL OF EVIDENCE

IV.

Pectus excavatum in motion: dynamic evaluation using real-time MRI

OBJECTIVES

The breathing phase for the determination of thoracic indices in patients with pectus excavatum is not standardized. The aim of this study was to identify the best period for reliable assessments of morphologic indices by dynamic observations of the chest wall using real-time MRI.

METHODS

In this prospective study, patients with pectus excavatum underwent morphologic evaluation by real-time MRI at 3 T between January 2020 and June 2021. The Haller index (HI), correction index (CI), modified asymmetry index (AI), and modified eccentricity index (EI) were determined during free, quiet, and forced breathing respectively. Breathing-related differences in the thoracic indices were analyzed with the Wilcoxon signed-rank test. Motion of the anterior chest wall was analyzed as well.

RESULTS

A total of 56 patients (11 females and 45 males, median age 15.4 years, interquartile range 14.3-16.9) were included. In quiet expiration, the median HI in the cohort equaled 5.7 (4.5-7.2). The median absolute differences (Δ) in the thoracic indices between peak inspiration and peak expiration were ΔHI = 1.1 (0.7-1.6, p < .001), ΔCI = 4.8% (1.3-7.5%, p < .001), ΔAI = 3.0% (1.0-5.0%, p < .001), and ΔEI = 8.0% (3.0-14.0%, p < .05). The indices varied significantly during different inspiratory phases, but not during expiration (p > .05 each). Furthermore, the dynamic evaluation revealed three distinctive movement patterns of the funnel chest.

CONCLUSIONS

Real-time MRI reveals patterns of chest wall motion and indicate that thoracic indices of pectus excavatum should be assessed in the end-expiratory phase of quiet expiration.

KEY POINTS

• The thoracic indices in patients with pectus excavatum depend on the breathing phase. • Quiet expiration represents the best breathing phase for determining thoracic indices. • Real-time MRI can identify different chest wall motion patterns in pectus excavatum.

Stiffness reduction of the rib cage to perform a minimally invasive pectus excavatum repair: biomechanical evaluation

OBJECTIVES

To study the influence of sternal transection and costal chondrotomies on the stiffness and stresses in the rib cage of adult patients undergoing Nuss pectus excavatum procedure.

METHODS

Four pectus excavatum models with different Haller indexes were created by parameterizing a 3D model of a rib cage obtained based on a computed tomography scan of a patient with no pectus deformity. Using the finite element method, insertion of intrathoracic bars into all models was simulated in 3 conditions, namely, non-intervened, transverse sternal section and costal chondrotomies. Stiffness, stress distribution and maximum stresses for each case were obtained and compared.

RESULTS

Transverse sternotomy provided a reduction of 44% to 54% in the stiffness of the rib cage, depending on the Haller index analysed, while chondrotomies promoted a stiffness reduction of 70%. Stress distribution in the rib cage followed similar pattern for all the tested Haller index, but the maximum stress decreased by 36% when performing a transverse sternotomy, whereas when performing costal chondrotomies, it decreased by 47%.

CONCLUSIONS

Computational results report that transverse sternotomy reduces appreciably the stiffness of the rib cage, while costal chondrotomies promote even a higher stiffness reduction. Thus, these surgical procedures could improve the clinical outcomes of adult patients undergoing a pectus excavatum repair.

Prevalence and prognosis of pericardial effusion in patients affected by pectus excavatum: A case-control study

BACKGROUND

The presence of pectus excavatum(PEX) has been occasionally associated with pericardial effusion. Aim of the present study was to compare incidence and prognosis of pericardial effusion in a group of unselected patients with PEX vs a control group.

METHODS

From a prospective registry of consecutive patients who underwent chest CT for cardiovascular disease, subjects with a radiological diagnosis of PEX were retrospectively identified (cases); from the same registry patients (controls) without rib cage abnormalities were randomly selected, until a 1:2 ratio was reached. The presence of pericardial effusion at CT was quantified. Follow-up was obtained for a composite end-point: cardiac tamponade, need for pericardiocentesis, need for cardiac surgery for relapsing pericardial effusion.

RESULTS

A total of 43 patients with PEX (20 females) and a control group of 86 cases (31 females) without rib cage abnormalities were identified. Pericardial effusion evaluated at CT was significatively more prevalent in patients with PEX vs control group, 37.2% vs 13.9% (p < 0.001), respectively; four patients with PEX (9.3%) had at least moderate pericardial effusion vs no subjects among the controls (p = 0.004). PEX diagnosis was significantly associated to pericardial effusion at multi-variate analysis (OR95%CI 10.91[3.47-34.29], p < 0.001). At a mean follow-up of 6.5 ± 3.4 years no pericardial events were recorded.

CONCLUSION

Our findings support the higher prevalence of pericardial effusion in patients with PEX when compared to a control group. The absence of adverse pericardial events at follow-up suggest the good prognosis of these effusions, that in the appropriate clinical setting might not be considered "idiopathic".

Customized Two-Dimensional Computed Tomography-Guided Preoperative Pectus Bar Shaping

INTRODUCTION

Successful minimally invasive repair of pectus excavatum relies on a pectus bar that closely conforms to the desired shape of the sternum and ribs to produce optimal elevation and remodeling. However, the present method of empirical intraoperative bar shaping is tedious and risks trauma to surrounding structures. To overcome this, we devised a technique using a life-sized computed tomography (CT) printout of the patient's chest wall to guide preoperative bar bending.

METHODS

A 5-cm-wide polymethylmethacrylate block placed on the sternum as the patient underwent chest CT was used as a marker to guide scaling of an axial screenshot of the patient's chest to life-size. This life-size image was printed and the planned correction of the patient's chest wall was traced onto it. The pectus bar was bent according to this template. Patient demographics, Haller index, surgical indications, operative technique, complications, aesthetic and functional improvements, and overall satisfaction were assessed.

RESULTS

Thirty patients (4 women) underwent primary minimally invasive repair of pectus excavatum with a single pectus bar shaped preoperatively over an 8-year period. The average age and Haller index was 20.6 years and 5.4, respectively. The mean operative time was 66.4 minutes. Satisfactory sternal elevation was attained with a single attempt at bar insertion in all cases. Two patients had pneumothoraxes that resolved without intervention. The mean follow-up period was 50.1 months. There were no cases of bar migration or recurrence of deformity after bar removal. On a 5-point Likert scale, all patients indicated an improvement in aesthetic appearance (4.6), and patients with physical symptoms (10) reported an improvement in function (4.4). The overall satisfaction score was 4.7.

CONCLUSIONS

This technique of CT-guided preoperative pectus bar shaping is straightforward, eliminates the need for intraoperative revisions to bar shape, and achieves effective correction of the pectus excavatum deformity. All patients were satisfied with the aesthetic, functional, and overall outcomes.

What Can Proton Beam Therapy Achieve for Patients with Pectus Excavatum Requiring Left Breast, Axilla and Internal Mammary Nodal Radiotherapy?

AIMS

Exposure of the heart to radiation increases the risk of ischaemic heart disease, proportionate to the mean heart dose (MHD). Radiotherapy techniques including proton beam therapy (PBT) can reduce MHD. The aims of this study were to quantify the MHD reduction achievable by PBT compared with volumetric modulated arc therapy in breath hold (VMAT-BH) in patients with pectus excavatum (PEx), to identify an anatomical metric from a computed tomography scan that might indicate which patients will achieve the greatest MHD reductions from PBT.

MATERIALS AND METHODS

Sixteen patients with PEx (Haller Index ≥2.7) were identified from radiotherapy planning computed tomography images. Left breast/chest wall, axilla (I-IV) and internal mammary node (IMN) volumes were delineated. VMAT and PBT plans were prepared, all satisfying target coverage constraints. Signed-rank comparisons of techniques were undertaken for the mean dose to the heart, ipsilateral lung and contralateral breast. Spearman's rho correlations were calculated for anatomical metrics against MHD reduction achieved by PBT.

RESULTS

The mean MHD for VMAT-BH plans was 4.1 Gy compared with 0.7 Gy for PBT plans. PBT reduced MHD by an average of 3.4 Gy (range 2.8-4.4 Gy) compared with VMAT-BH (P < 0.001). PBT significantly reduced the mean dose to the ipsilateral lung (4.7 Gy, P < 0.001) and contralateral breast (2.7 Gy, P < 0.001). The distance (mm) at the most inferomedial extent of IMN volume (IMN to heart distance) negatively correlated with MHD reduction achieved by PBT (Spearman's rho -0.88 (95% confidence interval -0.96 to -0.67, P < 0.001)).

CONCLUSION

For patients with PEx requiring left-sided breast and IMN radiotherapy, a clinically significant MHD reduction is achievable using PBT, compared with the optimal photon technique (VMAT-BH). This is a patient group in whom PBT could have the greatest benefit.

Does chest wall conformation influence myocardial strain parameters in infants with pectus excavatum?

PURPOSE

To investigate the possible influence of chest wall conformation on myocardial strain parameters in a consecutive population of infants with pectus excavatum (PE), noninvasively assessed by modified Haller index (MHI).

METHODS

Sixteen consecutive PE infants (MHI >2.5) and 44 infants with normal chest shape (MHI ≤2.5) entered in this prospective case-control study. All infants underwent evaluation by neonatologist, transthoracic echocardiography implemented with two-dimensional speckle tracking echocardiography (2D-STE) analysis of both ventricles and MHI assessment (ratio of chest transverse diameter over the distance between sternum and spine), at two time points: within 3 days and at about 40 days of life.

RESULTS

At 2.1 ± 1 days of life, compared to controls (MHI = 2.01 ± 0.2), PE infants (MHI = 2.76 ± 0.2) were diagnosed with significantly smaller cardiac chambers dimensions. Biventricular contractile function and hemodynamics were similar in both groups of infants. Left ventricular (LV) global longitudinal strain (GLS) (-16.0 ± 2.8 vs. -21.7 ± 2.2%), LV-global circumferential strain (GCS) (-16.3 ± 2.7 vs. -24.0 ± 5.2%), LV-global radial strain (GRS) (24.2 ± 3.0 vs. 31.5 ± 6.3%), and right ventricular free wall longitudinal strain (RVFWLS) (-16.0 ± 3.2 vs. -22.3 ± 4.4%) were significantly reduced in PE infants versus controls (all p < 0.001). A strong inverse correlation between MHI and the following parameters: LV-GLS (r = -0.92), LV-GCS (r = -0.88), LV-GRS (r = -0.87), and RVFWLS (r = -0.88), was demonstrated in PE infants, but not in controls, in perinatal period (all p < 0.001). Analogous results were obtained at 36.8 ± 5.2 days after birth.

CONCLUSIONS

Abnormal chest anatomy progressively impairs myocardial strain parameters in PE infants. This impairment might reflect intraventricular dyssynchrony due to compressive phenomena rather than intrinsic myocardial dysfunction.

Presumed acquired dynamic pectus excavatum in a cat

An 11-year-old, spayed female American domestic shorthair cat was presented with open-mouth breathing and dyspnea due to respiratory tract disease. Radiographically, there was thickening of the retropharyngeal soft tissue and soft palate, focal pulmonary change, and severe pectus excavatum (PE), best seen on the left lateral view. Repeat thoracic radiographs 4 months later showed persistent PE, but only on the right lateral view; PE was absent on the left lateral view. The dynamic component of the observed PE was presumably acquired secondary to chronic upper respiratory disease and/or concurrent increased pliability of the thoracic wall from prolonged prednisolone treatment.

Automatic assessment of Pectus Excavatum severity from CT images using deep learning

Pectus excavatum (PE) is the most common abnormality of the thoracic cage, whose severity is evaluated by extracting three indices (Haller, correction and asymmetry) from computed tomography (CT) images. To date, this analysis is performed manually, which is tedious and prone to variability. In this paper, a fully automatic framework for PE severity quantification from CT images is proposed, comprising three steps: (1) identification of the sternue's greatest depression point; (2) detection of 8 anatomical keypoints relevant for severity assessment; and (3) measurements' geometric regularization and extraction. The first two steps rely on heatmap regression networks based on the Unet++ architecture, including a novel variant adapted to predict 1D confidence maps. The framework was evaluated on a database with 269 CTs. For comparative purposes, intra-observer, inter-observer and intra-patient variability of the estimated indices were analyzed in a subset of patients. The developed system showed a good agreement with the manual approach (a mean relative absolute error of 4.41%, 5.22% and 1.86% for the Haller, correction, and asymmetry indices, respectively), with limits of agreement comparable to the inter-observer variability. In the intrapatient analysis, the proposed framework outperformed the expert, showing a higher reproducibility between indices extracted from distinct CTs of the same patient. Overall, these results support the feasibility of the developed framework for the automatic, accurate and reproducible quantification of PE severity in a clinical context.

Recurrence of pectus excavatum in long-term follow-up after the Nuss procedure in young children based on the radiographic Haller index

BACKGROUND/PURPOSE

To show the changes of the thorax after bar removal in young children with pectus excavatum in long-term postoperative follow-up.

METHODS

A total of 173 patients who underwent Nuss procedure under the age of 10 years from January 2005 to December 2013 and underwent bar removal were retrospectively reviewed. Then, Patients who were followed-up for more than 5 years after bar removal were selected and assessed. All patients were evaluated with the Haller index (HI) by chest computed tomography before the Nuss procedure. Follow-up after bar removal was done by two-view radiography. Radiographic HI (rHI) change was evaluated from before bar removal, to immediately after bar removal, and 3 years and 5 years after bar removal.

RESULTS

Forty-two patients (35 boys, 7 girls) were followed-up for more than 5 years after bar removal. The average age at the Nuss procedure was 6.1 ± 1.3 years, and the average HI was 5.07 ± 1.54. The average age at bar removal was 8.5 ± 1.2 years. The average rHI was 2.47 ± 0.33 before bar removal, 2.75 ± 0.50 immediately after bar removal, 3.24 ± 0.64 at 3 years after bar removal, and 3.46 ± 0.91 at 5 years after bar removal. The rHI value increased significantly between all periods.

CONCLUSIONS

The Nuss procedure for young children may have the risk of recurrence during growth after bar removal.

LEVEL OF EVIDENCE

Level IV.

Thoracoscopic Costal Cartilage Excision Combined with the Nuss Procedure for Patients with Asymmetrical Pectus Excavatum

Background and Aims: We performed thoracoscopic costal cartilage excision (TCCE) combined with the Nuss procedure to correct asymmetrical pectus excavatum (PE). We reviewed the efficacy of combined TCCE and Nuss procedure for asymmetric PE. Patients and Methods: Overall, 8 patients with asymmetrical PE underwent TCCE with the Nuss procedure. The Haller index, asymmetry index, and angle of sternal rotation were calculated using preoperative computed tomography. The procedure was performed using bilateral 2.5-cm incisions at the same level of the deepest chest wall depression. The most depressed three to four costal cartilages were partially resected through a right mini-thoracotomy. Subsequently, one or two titanium bars were implanted and secured with stabilizers. The cosmetic outcome was evaluated on the following four ratings: excellent, good, fair, and failure ( = recurrence). Results: The median age at surgery was 14.5 years (8-20 years). The number of bars was one in 3 cases and two in 5 cases. The preoperative Haller index, asymmetry index, and angle of sternal rotation were 4.3 (3.5-5.9), 1.15 (1.04-1.26), and 21.5° (15°-31°), respectively; 2 patients had scoliosis before the Nuss procedure. Complications included surgical site infection and hemothorax. Median follow-up time was 25.5 months (3-63). Bars were removed in 3 patients, 3 years postoperatively. Cosmetic results were excellent, 4; good, 2; fair, 1; failure, 1. Both patients with scoliosis had poor outcomes (fair, 1; failure, 1). Conclusions: Combined TCCE with Nuss procedure is considered safe and effective for patients with asymmetrical PE. Careful long-term follow-up is required, especially in cases with scoliosis.

False-positive electrocardiographic changes during exercise test in a patient with pectus excavatum

Exercise-induced ST-segment changes simulating myocardial ischemia have been described in otherwise normal subjects during hyperventilation. We present the case of a 60-year-old man with pectus excavatum showing significant exercise-induced "pseudo-ischaemic" ST-segment changes with neither coronary artery disease nor anxiety-induced hyperventilation. We found no report of the possible causative role of a narrow antero-posterior chest diameter in inducing "pseudo-ischaemic" ST-segment changes during exercise stress test in the literature.

Outpatient monitoring of Pectus Excavatum: a Neural Network-based approach

Pectus Excavatum (PE) is a congenital anomaly of the ribcage, at the level of the sterno-costal plane, which consists of an inward angle of the sternum, in the direction of the spine. PE is the most common of all thoracic malformations, with an incidence of 1 in 300-400 people. To monitor the progress of the pathology, severity indices, or thoracic indices, have been used over the years. Among these indices, recent studies focus on the calculation of optical measures, calculated on the optical scan of the patient's chest, which can be very accurate without exposing the patient to invasive treatments such as CT scans. In this work, data from a sample of PE patients and corresponding doctors' severity assessments have been collected and used to create a decision tool to automatically assign a severity value to the patient. The idea is to provide the physician with an objective and easy to use measuring instrument that can be exploited in an outpatient clinic context. Among several classification tools, a Probabilistic Neural Network was chosen for this task for its simple structure and learning mode.

Prevalence of pectus excavatum in an adult population-based cohort estimated from radiographic indices of chest wall shape

BACKGROUND

Pectus excavatum is the most common chest wall skeletal deformity. Although commonly evaluated in adolescence, its prevalence in adults is unknown.

METHODS AND FINDINGS

Radiographic indices of chest wall shape were analyzed for participants of the first (n = 2687) and second (n = 1780) phases of the population-based Dallas Heart Study and compared to clinical cases of pectus (n = 297). Thoracic computed tomography imaging studies were examined to calculate the Haller index, a measure of thoracic axial shape, and the Correction index, which quantitates the posterior displacement of the sternum relative to the ribs. At the level of the superior xiphoid, 0.5%, 5% and 0.4% of adult Dallas Heart Study subjects have evidence of pectus excavatum using thresholds of Haller index >3.25, Correction index >10%, or both, respectively. Radiographic measures of pectus are more common in females than males and there is a greater prevalence of pectus in women than men. In the general population, the Haller and Correction indices are associated with height and weight, independent of age, gender, and ethnicity. Repeat imaging of a subset of subjects (n = 992) demonstrated decreases in the mean Haller and Correction indices over seven years, suggesting change to a more circular axial thorax, with less sternal depression, over time.

CONCLUSIONS

To our knowledge, this is the first study estimating the prevalence of pectus in an unselected adult population. Despite the higher reported prevalence of pectus cases in adolescent boys, this study demonstrates a higher prevalence of radiographic indices of pectus in adult females.

Prevalence of pectus excavatum (PE), pectus carinatum (PC), tracheal hypoplasia, thoracic spine deformities and lateral heart displacement in thoracic radiographs of screw-tailed brachycephalic dogs

Pectus excavatum, thoracic spine deformities, tracheal hypoplasia and lateral heart displacement are frequently described in brachycephalic dog breeds. Pectus carinatum is described sporadically, although the authors' observations demonstrate that it may occur in certain brachycephalic dog breeds. It was hypothesised that dogs of screw-tailed brachycephalic breeds carry a greater risk of these anomalies than normal-tailed brachycephalic breeds, and that there could a relation between the presence of pectus excavatum or pectus carinatum and thoracic spine deformities, tracheal hypoplasia and lateral heart displacement. During retrospective studies, these anomalies were identified in lateral and dorso-ventral radiographs of the thorax in brachycephalic dog breeds. A statistical analysis revealed that the frequency of pectus excavatum occurrence in screw-tailed and normal-tailed brachycephalic dog breeds is similar. The greatest risk of pectus excavatum occurrence is carried by two breeds: Maltese (60%) and English Bulldog (58%), while for pectus carinatum: Pug (41%) and French Bulldog (18%). Dogs of screw-tailed brachycephalic breeds carry a greater risk of kyphosis (p < 0.0001), tracheal hypoplasia occurrence (p < 0.0001), compared to "normal-tailed" breeds. The hypothesis concerning a relation between the presence of pectus excavatum or pectus carinatum and the other anomalies studied was not confirmed (p > 0.05). It was demonstrated that in dogs of brachycephalic breeds there was a greater risk of co-incidence between kyphosis of the thoracic spine and lateral heart displacement (p = 0.038), as well as kyphosis of the thoracic spine and tracheal hypoplasia (p = 0.003).

[Inferior vena cava compression in children with pectus excavatum]

INTRODUCTION

In severe cases of pectus excavatum (PE) the sternal depression may cause distortion of the cardiac chambers and great vessels. The aim of our study was to determine if the sternal impingement causes significant inferior vena cava (IVC) compression.

METHODS

Retrospective study of patients with severe PE assessed between 2015-2017. The antero-posterior (AP) and transverse diameters of the suprahepatic IVC were measured on a cardiac-MRI at the level of the diaphragmatic hiatus. Results were compared with patients that had a thoracic image study performed for other causes, adjusting for age and sex.

RESULTS

Among the 81 patients, 28 cases and 53 controls, 63% were males and had a mean age of 12.9±0.5 yrs. Significant differences were found between groups in both AP and transverse diameter of the IVC: 13.3±0.75 mm vs. 15.8±0.76 mm (p=0.001) and 28.8±1.34 mm vs. 27.1±0.89mm (p=0.045) respectively. After adjusting for age and sex, these differences were only statistically significant for AP IVC diameter in males 12.7±0.5 mm (95% CI 11.66-13.79 mm) vs. 16.6±0.5 mm (95% CI 15.69-17.56 mm) (p=0.000). The Pearson correlation coefficient for the Haller index was r=0.471 (p=0.01).

CONCLUSION

Male patients with severe sternal depression show changes in the IVC diameter that may correspond to compression. These changes are correlated with the severity of the deformity and can justify certain clinical symptoms and cardiac function abnormalities in patients with severe PE.

Characteristics of mitral valve leaflet length in patients with pectus excavatum: A single center cross-sectional study

The mitral valve morphology in patients with pectus excavatum (PE) has not been fully investigated. Thirty-five patients with PE, 46 normal controls, and patients with hypertrophic cardiomyopathy (HCM) who underwent 2 leaflet length measurements of Carpentier classification P2 and A2 using a transthoracic echocardiography were retrospectively investigated. The coaptation lengths and depths, papillary muscle tethering length, and mitral annular diameters were also measured. The P2 and A2 lengths were separately compared between 2 groups: older than 16 years and 16 years or younger. Furthermore, the correlations between actual P2 or A2 lengths and Haller computed tomography index, an index of chest deformity, were investigated in patients with PE exclusively. Among subjects older than 16 years, patients with PE had significantly shorter P2, longer A2, shorter copatation depth, and longer papillary muscle tethering length compared with normal controls. Similarly, patients with PE had significantly shorter P2 and shorter coaptation depth even compared with patients with HCM, while no significant difference was found in A2 length and papillary muscle tethering length. The same tendency was noted between 4 normal controls and 7 age- and sex-matched patients with PE ≤ 16 years old. No significant difference regarding A2/P2 ratio was found between patients with PE older and younger than 16 years. No significant correlation between the Haller computed tomography index and actual mitral leaflet lengths in patients with PE older than 16 years was noted; the same was observed for A2/P2 in all patients with PE. In conclusion, the characteristic features of the shorter posterior mitral leaflet, the longer anterior mitral leaflet, the shorter coaptation depth, and the longer papillary muscle tethering length in patients with PE was demonstrated. This finding might provide a clue regarding the etiology of mitral valve prolapse in PE at its possible earliest form.

[Reliability of the correction index in the surgical indication for pectus excavatum]

OBJECTIVE

The Haller index (HI) is widely used to indicate surgical intervention in patients with pectus excavatum (PE). However, in patients with an atypical thoracic morphology, the severity of the defect can be incorrectly estimated. We propose comparing this index with the correction index (CI).

MATERIAL AND METHODS

We analyzed clinical data and CT scans of 50 patients who consulted for PE in our center between 2010 and 2017. Haller index (HI), Correction index (CI) and ideal thoracic index (ITI) were calculated for each patient. The ITI allowed dividing the sample into two groups based on the thoracic morphology by excluding the PE component, therefore separating those with thorax too wide or too narrow from the standard patients. A standard group (36 patients) and a non-standard group (14 patients) were generated, among which the HI and the CI were correlated.

RESULTS

The mean HI and CI of all patients were 3.99 and 27%, respectively. 31 of the 50 patients (62%) underwent intervention, 8 of them with an HI below 3.25. When comparing both groups, there was a moderate correlation between HI and CI in the standard group (Spearman r 0.799, p <0.01) and a greater correlation in the non-standard group (Spearman r 0.858, p <0.01).ween the scale and the presence of foreign body, except for SCORE 1, which was 57% what we attribute to an information bias. If the foreign body were not nuts, inorganic or bone, its aspiration was very unlikely, that is why we included it in the SCORE with -1.

CONCLUSION

In our cohort, correlation of HI and CI was not different between both groups of patients. The CI did not prove its superiority when compared to HI in the surgical indication of patients with PE.

Paroxysmal Atrial Fibrillation in Patients Successfully Treated by Radiofrequency Catheter Ablation with Severely Compression, Lateral Displacement, and Clockwise Rotation of Their Hearts due to Severe Pectus Excavatum

Two cases with severe pectus excavatum and symptomatic atrial fibrillation (AF) underwent radiofrequency catheter ablation (RFCA). Their chest X-ray and computed tomography (CT) findings revealed lateral displacement and clockwise rotation of their hearts, and severe right atrial and mild right ventricular compression against the sternum, but no left atrium compression against the spinal column. The procedure was therefore carefully performed under guidance with CT, intra-cardiac echography, atriography, and a three-dimensions mapping system. Finally, the AF was successfully treated by RFCA without any complications. These findings underscore the importance of understanding cases of abnormal anatomy and carefully designing a strategy before performing any procedure.

Thoracic outlet syndrome (TOS): A case report of a rare complication after Nuss procedure for pectus excavatum

RATIONALE

The Nuss procedure has become a major alternative operation for patients with pectus excavatum (PE).

PATIENT CONCERNS

We report a case of 27-year-old man with PE who developed thoracic outlet syndrome (TOS) after the Nuss procedure. The patient showed clinical symptoms of brachial plexus compression.

DIAGNOSES

Further evaluation demonstrated a narrowed space between the first rib and the anterior scalene muscle and compressing the brachial plexus and vessels.

INTERVENTIONS

Nerve nourishing medicine and rehabilitation exercising were taken to restore the muscle strength.

OUTCOMES

Several months later, the clinical symptoms disappeared.

LESSONS

Medicine and rehabilitation exercising may benefit the functional recovery of impaired nerve in TOS in the early stage of TOS.

[Application of cameral-type three-dimensional scan in assessment of funnel chest]

OBJECTIVE

To evaluate the application of cameral-type three-dimensional (3D) scan in the assessment of funnel chest.

METHODS

Eighty children with funnel chest were collected from the Children's Hospital, Zhejiang University School of Medicine during June 2016 and December 2017. All patients underwent routine CT scan. In the same selected mediastinal window, the lowest point of the depression to the front of the spine was the anteroposterior diameter (A₁), and the maximum left to right diameter was B₁ (which was perpendicular to A₁). The ratio B₁/A₁ was calculated to get CT Haller index (CT-HI). In the same period, the chest wall scan was performed by EinScan-Pro 3D scanner, and the image was analyzed by GeoMedic image software. On the plane of the most concave point of the sternum, the distance from the lowest point of the skin to the back skin was the anteroposterior diameter (A₂), the maximum plane diameter was measured on the same plane (B₂), and the ratio B₂/A₂ was the 3D-Haller index (3D-HI). Pearson correlation analysis was used to analyze the consistency of the two measurements. Kappa test was used to analyze the consistency of surgical indication based on cutoff value of CT-HI and 3D-HI.

RESULTS

All children were able to cooperate with CT and 3D chest wall surface scan. The mean value of CT-HI was 3.82±0.96, and that of 3D-HI was 1.82±0.23. Pearson correlation analysis showed that the correlation coefficient between CT-HI and 3D-HI was 0.823 (P<0.01). When CT-HI > 3.2 and 3D-HI > 1.7 were set as cutoff values for indication of operation, the sensitivity and specificity of 3D-HI were 90.48% and 100.0%, respectively. 3D-HI was well consistent with CT-HI in surgical indication (Kappa=0.801).

CONCLUSIONS

s 3D scan can be used to assess the funnel chest in children, and 3D-HI>1.7 can be used as the cutoff value for surgical indication.

Occult RV systolic dysfunction detected by CMR derived RV circumferential strain in patients with pectus excavatum

Aims

To investigate the right ventricular (RV) strain in pectus excavatum (PE) patients using cardiac magnetic resonance tissue tracking (CMR TT).

Materials and methods

Fifty consecutive pectus excavatum patients, 10 to 32 years of age (mean age 15 ± 4 years), underwent routine cardiac magnetic resonance imaging (CMR) including standard measures of chest geometry and cardiac size and function. The control group consisted of 20 healthy patients with a mean age of 17 ± 5 years. RV longitudinal and circumferential strain magnitude was assessed by a dedicated RV tissue tracking software.

Results

Fifty patients with images of sufficient quality were included in the analysis. The mean right and left ventricular ejection fractions were 55 ± 5% and 59 ± 4%. The RV global longitudinal strain was -21.88 ± 4.63%. The RV circumferential strain at base, mid-cavity and apex were -13.66 ± 3.09%, -11.31 ± 2.79%, -20.73 ± 3.45%, respectively. There was no statistically significant decrease in right ventricular or left ventricular ejection fraction between patients and controls (p > 0.05 for each). There was no significant difference in RV global longitudinal strain between two groups (-21.88 ± 4.63 versus -21.99 ± 3.58; p = 0.93). However, there was significant decrease in mid-cavity circumferential strain magnitude in pectus patients compared with controls (-11.31 ± 2.79 versus -16.19 ± 2.86; p < 0.001). PE patients had a significantly higher basal circumferential strain (-13.66 ± 3.09% versus -9.76 ± 1.79; p < 0.001) as well as apical circumferential strain (-20.73 ± 3.45% versus -12.07 ± 3.38) than control group.

Conclusion

Mid-cavity circumferential strain but not longitudinal strain is reduced in pectus excavatum patients. Basal circumferential strain as well as apical circumferential strain were increased as compensatory mechanism for reduced mid-cavity circumferential strain. Further studies are needed to establish clinical significance of this finding.

Pectus Excavatum: A Review of Diagnosis and Current Treatment Options

Osteopathic medicine places a special emphasis on the musculoskeletal system, and understanding how chest wall structure may influence function is critical. Pectus excavatum is a common congenital chest wall defect in which the sternum is depressed posteriorly. Patients may present with complaints of chest wall discomfort, exercise intolerance, and tachycardia. The medical implications, diagnosis, and treatment options for patients with pectus excavatum are reviewed.

Does an external chest wall measurement correlate with a CT-based measurement in patients with chest wall deformities?

BACKGROUND

Measurements in chest wall deformities are typically conducted using a thorax caliper or a CT scan of the chest wall. This paper focuses on the possible correlation between these two methods to validate the reliability of the thorax caliper, minimize radiation exposure, and limit the usage of expensive imaging techniques.

METHODS

We evaluated 95 consecutive patients (77 pectus excavatum (PE), 17 pectus carinatum (PC), 1 mixed deformity) who received surgical correction of the anterior chest wall. The results of the external chest wall measurements and the CT-based measurements were statistically compared.

RESULTS

A significant correlation between the two measurements was observed in PE and PC at the highest point of the deformation. The strongest correlation was noted in PE. We also noted a correlation between the transverse diameter of the external measurement and the inner thoracic diameter of the CT scan but not for the sagittal diameters in the upper parts of the sternum.

CONCLUSIONS

Thorax caliper measurements are suitable for determining the sagittal thoracic diameter at the maximum level of the deformity and the transverse diameter with an accuracy comparable to that of CT measurements. Since these values key, the thorax caliper is reliable for monitoring and documenting chest wall malformations.

LEVEL OF EVIDENCE

Study of diagnostic test. Testing previously developed diagnostic criteria in a consecutive series of patients and a universally "gold" standard-Level I.

[Benefits of magnetic resonance for the study of pectus excavatum in children: initial experience]

INTRODUCTION/AIM OF THE STUDY

In patients with PE, cardiovascular alterations ensue as a result of the mediastinum compression caused by sternum impingement and is responsible of many of the symptoms. Anatomical and functional assessment is of the utmost importance for a comprehensive understanding of the disease and an adequate treatment plan. Our aim was to describe the use of magnetic resonance image (MRI) in the study of PE and whether it is comparable to imaging techniques.

PATIENTS AND METHODS

A retrospective study of the first 10 patients in which an MRI was performed as part of PE assessment within august 2015-2016. PE indexes were evaluated: Haller, correction, asymmetry, as well as sternal rotation. An analysis of right ventricular function was carried out comparing echocardiogram and MRI.

RESULTS

MRI scan on 10 patients showed the following findings: Haller index: inspiration: 3.75 (3.5-7.3) and expiration 4,9 (3.9-10.8), correction index of 24% (5-37%) and a sternal rotation of 12º (0-31º). The cardiovascular study showed a median ejection fraction of the right ventricle (EFRV) of 50% (38-64%), with 9 of the 10 patients under the normal value of 61% (54-71%). Echocardiographic findings underestimated functional alterations in all of the patients.

CONCLUSION

This initial study suggests that the use of MRI as a test of choice in the evaluation of PE subject to surgical correction is feasible. Absence of radiation offers the capacity of a complete and dynamic anatomical as well as cardiovascular study.

Minimally invasive repair of pectus excavatum in children: Results of a modified Nuss procedure

INTRODUCTION

Pectus excavatum (PE) is the most common deformity of the anterior thoracic wall. The Nuss technique allows the thorax to be reshaped with the aid of a retrosternal metallic bar. The aim of this study is to evaluate and compare the complication rate between the original Nuss technique and a lightly modified approach.

MATERIAL AND METHOD

We performed a retrospective single-center observational study based on the medical files of patients operated for PE in the Pediatric Surgery Unit between July 2004 and July 2015. We divided two patient groups according to the operating technique employed: the Nuss group (NG) and the modified Nuss group (MNG) with supplementary subxiphoid incision and bilateral thoracoscopy.

RESULTS

Twenty-seven patients were included: sixteen in the NG and eleven in the MNG. No significant differences were found between the two groups for all kinds of complications: total complication rate (50% for the NG versus 54% for the MNG, P>0.05), early (31% vs 46%, P>0.05), late (19% vs 9%, P>0.05), non-serious (37% vs 36%, P>0.05) or serious (13 vs 18%, P>0.05). There was no life threatening complication in the MNG, contrary to the NG. In the two groups, a significant difference was found (P=0.029) regarding the operating time: longer operating times (80±25min) were correlated with a higher complication rate.

CONCLUSION

The modified Nuss technique does not cause more complications than the original technique described by Nuss and it has the advantage to minimize the risk of heart damage.

Pectus Excavatum: More Than a Matter of Aesthetics

Pectus excavatum (PE) is the most common congenital chest abnormality, and affects males 5 times more frequently than females. PE results from improper fusion of the ribs with the sternum during embryologic development. The cardinal presenting sign is chest depression. Evaluation includes serial measurement of the chest deformity defect. Additional evaluation of cardiopulmonary function, including arrhythmias and pulmonary function tests, should be done as well. Computed tomography scans are used to determine the Haller index, a measure of deformity severity, with a measurement of greater than 3.2 deemed severe. The main indication of repair is decreased cardiopulmonary capacity, not cosmetic. Surgical repair should be timed such that it occurs after the pediatric growth spurt. Generally, the Nuss procedure, which is minimally invasive, is the first-line surgical repair. Ravitch, or open repair, is used for more complex or asymmetric deformities. [Pediatr Ann. 2016;45(11):e403-e406.].

Evaluation of thoracic factors after scoliosis surgery in patients with both scoliosis and pectus excavatum

PURPOSE

Pectus excavatum can negatively impact cardiac function during scoliosis surgery. Several authors reported severe hypotension associated with the prone position during scoliosis surgery in children that had both scoliosis and pectus excavatum. However, we could find no studies that evaluated the change in the thoracic factors, such as sternal tilt angle and Haller index after scoliosis surgery in patients with both scoliosis and pectus excavatum. The purpose of this study is to evaluate the change in thoracic factors after surgical treatment for scoliosis associated with pectus excavatum.

METHODS

We performed a retrospective review on 20 patients (10 males and 10 females) who underwent surgical treatment for scoliosis associated with pectus excavatum from August 2004 to April 2014 in our hospital. We investigated the scoliosis diagnosis, preoperative and postoperative Cobb and thoracic kyphosis (TK) angles, the change in TK after surgery and thoracic factors, including the AP and transverse diameters of the chest, the sternal tilt angle, and Haller index.

RESULTS

Patient mean age was 13.2 years old (4-27 years old) at surgery. Types of scoliosis were idiopathic in 8 patients, syndromic in 10, and neuromuscular in 2. The mean Cobb angles were 72.1° preoperatively and 19.0° postoperatively. Curve locations were thoracic in 13 patients, thoracolumbar in 4, and lumbar in 3. Surgical treatment of pectus excavatum was performed in 9 patients (45 %) before scoliosis treatment. Mean sternal tilt angles were 11.5° preoperatively and 11.1° postoperatively. Mean Haller indices were 4.8 preoperatively and 5.3 postoperatively. This was especially true for syndromic or neuromuscular scoliosis and thoracolumbar/lumbar curve type patients in which scoliosis surgery tended to worsen the Haller index.

CONCLUSION

The Haller index increased postoperatively in 11 of 20 patients, which means sternal depression deteriorated after scoliosis surgery in about 50 % of patients. We suggest that surgeons fully assess the thoracic factors in patients with scoliosis and pectus excavatum prior to performing scoliosis surgery and carefully monitor their patient's general condition during surgery.

Cardiac and arterial elastance and myocardial wall stress in children with pectus excavatum

OBJECTIVES

Pectus excavatum (PE) is one of the most common skeletal deformities of childhood. The study was undertaken to assess cardiac functions in children with PE.

METHODS

Echocardiography was performed on 32 children with PE and 40 age-matched healthy controls. The following parameters were monitored: meridional left ventricular (LV) wall stress (WSM), arterial elastance (Ea), LV elastance at end-systole derived by single beat (Ees(sb)), LV circumferential end-systolic wall stress (ESWSc), midwall shortening fraction (SFmid), predicted midwall fiber shortening for a measured fiber stress (midwall VCFc), myocardial fiber stress (MFS), LV end-systolic dimension (LVES), LV end-diastolic dimension (LVED) and end-systolic blood pressure (Pes), LV wall thickness at end-systole (hes). To assess the severity of PE, Haller index (HI) was calculated by computed tomography of the thorax.

RESULTS

SFmid, ESWSc, midwall VCFc and MFS were lower in PE children than in controls. The degree to which the parameters SFmid, ESWSc, midwall VCFc and MFS were altered in PE children was 14.9, 27.5, 20.3 and 20.3%, respectively. The minimum HI value of children with PE was 2.00, the maximum value was 4.93 and the arithmetic mean was 2.62 ± 0.56. Of the 32 children, 14 (43.75%) demonstrated mild deformity, 15 (46.88%) showed moderate and only 3 (9.37%) had severe deformity. In children with PE, there was no statistically significant correlation between the cardiac data (ESWSc, midwall VCFc, MFS, Ea, Ees(sb), LVES, LVED, Pes, hes) and HI.

CONCLUSION

We found ESWSc, MFS, midwall VCFc and SFmid to be lower in children with PE than in controls. We concluded that the myocardial contractility and afterload is affected in children with PE.

Costal Cartilages Do Not Overgrow in Patients with Pectus Excavatum

OBJECTIVE

The purpose of this study was to determine whether or not patients with pectus excavatum (PE) exhibit costal cartilage overgrowth compared to normal subjects.

MATERIALS AND METHODS

The computed tomography acquisitions of 32 patients with PE and 35 normal controls were analyzed. On axial images the length of the 4th-7th costal cartilages was measured to calculate the Haller index. The ratio between the length of the cartilages and the median of the transverse and longitudinal thorax diameters were recorded to account for anatomical variability. The length of the cartilages was compared between the PE and control subjects using the independent-samples t test. For patients with asymmetric PE the length of the 4th-7th costal cartilages was compared between the rotated and nonrotated sides.

RESULTS

The mean transverse and coronal thorax diameters were 233.29 ± 24.47 and 231.69 ± 22.47 mm for PE patients and 252.67 ± 37.25 and 238.64 ± 27.40 mm for controls, respectively, with no significant differences between the two groups (p = 0.816 and 0.145). The mean sagittal diameter (59.30 ± 14.21 mm) and Haller index (4.02 ± 1.34) in the PE group were significantly different from the controls (107.34 ± 19.59 and 2.2 ± 0.54 mm, respectively; p = 0.00). Actual and relative lengths of costal cartilages were similar in both PE subjects and controls for all 4 costal cartilages measured. In subjects with asymmetric PE, both relative and absolute costal cartilage lengths were similar on the rotated and nonrotated side.

CONCLUSIONS

The length of the 4th, 5th, 6th and 7th costal cartilages was similar in PE patients and the control subjects. These was also similar between the rotated and nonrotated sides of the sternum in patients with asymmetric PE.

Chest modeling and personalized surgical planning for pectus excavatum

Pectus excavatum is among the most common major congenital anomalies of the chest wall whose correction can be performed via minimally invasive Nuss technique that places a pectus bar to elevate the sternum anteriorly. However, the size and bending of the pectus bar are manually modeled intraoperatively by trial-and-error. The procedure requires intense pain management in the months following surgery. In response, we are developing a novel distraction device for incremental and personalized PE correction with minimal risk and pain, akin to orthodontic treatment using dental braces. To design the device, we propose in this study a personalized surgical planning framework for PE correction from clinical noncontrast CT. First, we segment the ribs and sternum via kernel graph cuts. Then costal cartilages, which have very low contrast in noncontrast CT, are modeled as 3D anatomical curves using the cosine series representation and estimated using a statistical shape model. The size and shape of the correction device are estimated through model fitting. Finally, the corrected/post-surgical chest is simulated in relation to the estimated shape of correction device. The root mean square mesh distance between the estimated cartilages and ground truth on 30 noncontrast CT scans was 1.28 +/- 0.81 mm. Our method found that the average deformation of the sterna and cartilages with the simulation of PE correction was 49.71 +/- 10.11 mm.

Engineering-aided treatment of chest deformities to improve the process of breathing

In this paper, the application of new visualization technologies in correction of funnel chest is presented. Often, such defects cause problems with breathing, and therefore, to improve the cardiorespiratory efficiency, a correction is required. The virtual model of chest was formulated to determine the strains and stresses after correction of deformation with using the stabilizing plate. From biomechanical point of view, the knowledge of the load-affecting stabilizer is necessary to select optimal parameters of the plate. The force-affecting plate that was used in the correction of chest deformation by Nuss method was determined on the basis of finite element model of funnel chest. The main aim of this work was to select the optimal thickness of plate. Calculations were conducted for three alternative constraints.

[Management of pectus excavatum]

Management of pectus excavatum Congenital chest wall deformities are considered to be anomalies in chest wall growth related to excessive or insufficient growth (aplasia or dysplasia) of the osseous or cartilaginous structures or the rib cage. These deformities are associated in 95% to overgrowth leading into depression (pectus excavatum) or protuberance of the sternum (pectus carinatum). Pectus excavatum may lead to cardiopulmonary disorder or impact on patient's self-esteem. The management of pectus excavatum has evolved this last decade with minimal invasive repair.

Correlation of asymmetric chest wall deformity and growth in patients with pectus excavatum

PURPOSE

Pectus excavatum involves wide range of chest wall depression. The degree of depression or asymmetry varies between young and adolescent patients. It has not been clear how the deformity progresses as patients grow. To elucidate the change of asymmetric deformity, preoperative computed tomography (CT) scan was evaluated according to different age groups.

METHODS

Preoperative CT scans of 154 patients with pectus excavatum were collected and analyzed using Haller's CT index, asymmetric index and sternal rotation angle. Patients were divided into 5 age groups as follows; group 1: 4-6 y (n=53), group 2: 7-9 y (n=25), group 3: 10-12 y (n=25), group 4: 13-15 y (n=23), group 5: 16-23 y (n=28). The degree of asymmetric chest wall deformity was expressed using sternal rotation angle as follows; symmetrical (-5º to +5º), left-mild (-5º to -15º), right-mild (+5º to +15º), right-moderate (+15º to +25º) and right-severe (over +25º).

RESULTS

As the age of patients increased, asymmetric index increased from 1.025±0.065 in group 1 to 1.124±0.111 in group 5 and sternal rotation angle also increased from 6.11±8.61 in group 1 to 15.41±11.98 in group 5. In these two parameters, significant difference was seen between group 1 and 4, group 2 and 4, group 1 and 5 and group 2 and 5. However, average CT index revealed no significant difference in any age groups. In group 1, 83% of patients were classified in symmetrical or left- and right-mild. The incidence of right-moderate plus right-severe was 17% in group 1, 20% in group 2, 40% in group 3, 52.1% in group 4 and 50% in group 5.

CONCLUSIONS

The degree of chest depression did not show any change in all age groups. Asymmetric deformity on the right side progressed around the age of 10 to 12. Half of patients over the age of 13 showed moderate or severe asymmetry. These results were suggestive to consider the optimum age for the correction of pectus excavatum.

Treatment of left sided breast cancer for a patient with funnel chest: volumetric-modulated arc therapy vs. 3D-CRT and intensity-modulated radiotherapy

This case study presents a rare case of left-sided breast cancer in a patient with funnel chest, which is a technical challenge for radiation therapy planning. To identify the best treatment technique for this case, 3 techniques were compared: conventional tangential fields (3D conformal radiotherapy [3D-CRT]), intensity-modulated radiotherapy (IMRT), and volumetric-modulated arc therapy (VMAT). The plans were created for a SynergyS® (Elekta, Ltd, Crawley, UK) linear accelerator with a BeamModulator™ head and 6-MV photons. The planning system was Oncentra Masterplan® v3.3 SP1 (Nucletron BV, Veenendal, Netherlands). Calculations were performed with collapsed cone algorithm. Dose prescription was 50.4 Gy to the average of the planning target volume (PTV). PTV coverage and homogeneity was comparable for all techniques. VMAT allowed reducing dose to the ipsilateral organs at risk (OAR) and the contralateral breast compared with IMRT and 3D-CRT: The volume of the left lung receiving 20 Gy was 19.3% for VMAT, 26.1% for IMRT, and 32.4% for 3D-CRT. In the heart, a D(15%) of 9.7 Gy could be achieved with VMAT compared with 14 Gy for IMRT and 46 Gy for 3D-CRT. In the contralateral breast, D(15%) was 6.4 Gy for VMAT, 8.8 Gy for IMRT, and 10.2 Gy for 3D-CRT. In the contralateral lung, however, the lowest dose was achieved with 3D-CRT with D(10%) of 1.7 Gy for 3D-CRT, and 6.7 Gy for both IMRT and VMAT. The lowest number of monitor units (MU) per 1.8-Gy fraction was required by 3D-CRT (192 MU) followed by VMAT (518 MU) and IMRT (727 MU). Treatment time was similar for 3D-CRT (3 min) and VMAT (4 min) but substantially increased for IMRT (13 min). VMAT is considered the best treatment option for the presented case of a patient with funnel chest. It allows reducing dose in most OAR without compromising target coverage, keeping delivery time well below 5 minutes.

[Lady Windermere syndrome]

We describe the case of a 68 year old lady with a pectus excavatum, chronic cough, dyspnoea, and fever. The CT scan showed fibronodular infiltrates and bronchectases. Bacterial culture revealed a Mycobacterium avium-intracellulare infection. A tritherapy was initiated and, 10 months later, the patient had greatly improved.

Chest wall kinematics in young subjects with Pectus excavatum

Quantifying chest wall kinematics and rib cage distortion during ventilatory effort in subjects with Pectus excavatum (PE) has yet to be defined. We studied 24 patients: 19 during maximal voluntary ventilation (MVV) and 5 during MVV and cycling exercise (CE). By optoelectronic plethysmography (OEP) we assessed operational volumes in upper rib cage, lower rib cage and abdomen. Ten age-matched healthy subjects served as controls. Patients exhibited mild restrictive lung defect. During MVV end-inspiratory and end-expiratory volumes of chest wall compartments increased progressively in controls, whereas most patients avoided dynamic hyperinflation by setting operational volumes at values lower than controls. Mild rib cage distortion was found in three patients at rest, but neither in patients nor in controls did MVV or CE consistently affect coordinated motion of the rib cage. Rib cage displacement was not correlated with a CT-scan severity index. Conclusions, mild rib cage distortion rarely occurs in PE patients with mild restrictive defect. OEP contributes to clinical evaluation of PE patients.

An unusual presentation of Kartagener's syndrome

Kartagener's syndrome is a rare disorder which is seen in nearly half of the cases of primary ciliary dyskinesia. We report an unusual case of Kartagener's syndrome where the patient had associated ventricular septal defect, pectus excavatum and was fertile.

The search for stability: bar displacement in three series of pectus excavatum patients treated with the Nuss technique

OBJECTIVES

To compare bar displacement and complication rates in three retrospective series of patients operated on by the same surgical team.

METHOD

A retrospective medical chart analysis of the three patient series was performed. In the first series, the original, unmodified Nuss technique was performed. In the second, we used the ''third point fixation'' technique,and in the last series, the correction was performed with modifications to the stabilizer and stabilizer position.

RESULTS

There were no deaths in any of the series. Minor complications occurred in six (4.9%) patients: pneumothorax with spontaneous resolution (2), suture site infection (2), and bar displacement without the reoperation need (2). Major complications were observed in eight (6.5%) patients: pleural effusion requiring drainage (1), foreign body reaction to the bar (1), pneumonia and shock septic (1), cardiac perforation (1), skin erosion/seroma (1), and displacement that necessitated a second operation to remove the bar within the 30 days of implantation (3). All major complications occurred in the first and second series.

CONCLUSION

The elimination of fixation wires, the use of shorter bars and redesigned stabilizers placed in a more medial position results in a better outcome for pectus excavatum patients treated with the Nuss technique. With bar displacement and instability no longer significant postoperative risks, the Nuss technique should be considered among the available options for the surgical correction of pectus excavatum in pediatric patients.