Effects of Pectus Excavatum on the Spine of Pectus Excavatum Patients with Scoliosis

Novel techniques and future developments in minimally invasive pectus repair

After the paradigm shift in the treatment of excavated deformities caused by the introduction of the Nuss technique in 1998, several innovative technical modifications and new treatment modalities have radically changed the surgical approach of pectus excavatum in the last couple of years. These new trends attain different topics. On one hand, the use of three-dimensional (3D) printing and implant customization surge as a possibility for a wider audience as 3D printers become available with lower costs. They provide the surgeon with new elements that enable precise planning, simulation, and customized prostheses amidst a tendency to abandon standardization and incorporate personalized medicine. Another topic comprises mandatory sternal elevation, in the continuous search for safety first always. Complete thoracic remodeling as a goal of repair instead of addressing only focal depressions, leaving the upper chest or focal protrusions unresolved. Finally, although the current surgical approach has evolved significantly, many groups still use lateral stabilizers or direct implant fixation with sutures or wires to the ribs. These systems continue to prove unreliable in preventing implant displacement. Fortunately, the bridge technique, described in this review, has come to address this sometimes fatal issue with encouraging results. We provide an updated overview of the latest developments regarding these concepts, related to the current state-of-the-art of the treatment of pectus excavatum.

Correlation of anterior chest wall anomalies and spinal deformities: a comprehensive descriptive study

PURPOSE

To investigate the association and evaluate the characteristics between different types of anterior chest wall and spinal deformities.

METHODS

A total of 548 patients with anterior chest wall deformities were included in this study. Clinical and radiological examinations were performed to determine spinal deformities. The type and severity of the spinal deformities were evaluated and their relationships with chest wall deformity subtypes were statistically analyzed.

RESULTS

Spinal deformities were identified in 93 (16.97%) patients. The patients were subdivided into 71 (76.3%) male and 22 (23.7%) female patients. A spinal deformity was detected in 57 (13%) of 418 pectus excavatum (PE) patients, in 23 (19%) of 117 pectus carinatum (PC) patients, and in all patients with mixed pectus deformity (PE + PC), syndromic deformity and rib anomalies. In the PE group, scoliosis, and kyphosis were observed at 57.9 and 31.6%, respectively. In the PC group, these rates were 43.5 and 47.8%, respectively. Idiopathic scoliosis was observed in 42 (77.7%) and constituted the most common scoliosis subgroup. The main thoracic curvature was the most common curve pattern, which was observed in 15 (35.7%) patients with idiopathic scoliosis.

CONCLUSIONS

Idiopathic scoliosis with main thoracic curvature is the most common deformity in patients with anterior chest wall deformity. Spinal deformities are more common in male patients with chest deformities. Kyphosis is found in a significant number of PE and PC patients. Patients with mixed PE and PC, rib anomalies, and syndromic disease are more likely to have spinal deformities.

Automatic implant shape design for minimally invasive repair of pectus excavatum using deep learning and shape registration

Minimally invasive repair of pectus excavatum (MIRPE) is an effective method for correcting pectus excavatum (PE), a congenital chest wall deformity characterized by concave depression of the sternum. In MIRPE, a long, thin, curved stainless plate (implant) is placed across the thoracic cage to correct the deformity. However, the implant curvature is difficult to accurately determine during the procedure. This implant depends on the surgeon's expert knowledge and experience and lacks objective criteria. Moreover, tedious manual input by surgeons is required to estimate the implant shape. In this study, a novel three-step end-to-end automatic framework is proposed to determine the implant shape during preoperative planning: (1) The deepest depression point (DDP) in the sagittal plane of the patient's CT volume is automatically determined using Sparse R-CNN-R101, and the axial slice containing the point is extracted. (2) Cascade Mask R-CNN-X101 segments the anterior intercostal gristle of the pectus, sternum and rib in the axial slice, and the contour is extracted to generate the PE point set. (3) Robust shape registration is performed to match the PE shape with a healthy thoracic cage, which is then utilized to generate the implant shape. The framework was evaluated on a CT dataset of 90 PE patients and 30 healthy children. The experimental results show that the average error of the DDP extraction was 5.83 mm. The end-to-end output of our framework was compared with surgical outcomes of professional surgeons to clinically validate the effectiveness of our method. The results indicate that the root mean square error (RMSE) between the midline of the real implant and our framework output was less than 2 mm.

Factors reducing psychological satisfaction after the Nuss procedure in pediatric patients

PURPOSE

We examined patient satisfaction with postoperative chest appearance after Nuss procedure and analyzed the factors for postoperative low satisfaction.

METHODS

We retrospectively reviewed data of 133 patients who underwent the Nuss procedure from 2000 to 2016. Their medical records, X-rays, and computed tomography scans were evaluated. Haller index and concave rate were used as objective indices of the deformity. The questionnaires were used to evaluate satisfaction with the chest appearance by a linear scale including five markers (1: dissatisfaction, 5: satisfaction). The patients were divided into two groups: the low satisfaction (score = 1, 2) and the high satisfaction (score = 3-5).

RESULTS

The median age during the Nuss procedure was 7.6 (interquartile range, 5.8-12.8) years. Out of 133, 65 patients replied, and the mean postoperative satisfaction score was 3.8 ± 0.2. Out of the 65 respondents, 16 patients (24.6%) were classified as low satisfaction group. Haller index and concave rate were significantly higher and the previous instances of chest operation history were more frequent in the low satisfaction group than in the high satisfaction group, although there was no significant intergroup difference in terms of the postoperative concave rate.

CONCLUSIONS

Severe deformity and previous chest operation history were considered to be factors for low satisfaction.

Clinical significance of concomitant pectus deformity and adolescent idiopathic scoliosis: systematic review with best evidence synthesis

BACKGROUND

A misbalance in forces is proposed for causing adolescent idiopathic scoliosis (AIS). AIS is therefore correlated to adjacent musculoskeletal pathologies. Its concomitance with idiopathic pectus deformities (PD) is underexposed. This systematic review analyzes the clinical significance and predictive factors of PD-associated AIS.

METHODS

A search was performed in PubMed, UpToDate, Embase, and Cochrane. A study was included if it: assessed the association between PD and scoliosis (category I), reported a prevalence of scoliosis in PD patients (category II), or addressed other topics about PD-associated AIS (category III). Studies in category I discussing predictive factors were appraised using the Quality in Prognosis Studies tool. Because of heterogeneity among the studies, predictive factors were analyzed according to a best evidence synthesis. A mean prevalence of scoliosis in PD patients was calculated using category I and II. Category III was narratively reviewed.

RESULTS

Forty-eight studies were included (I:19, II:21, III:8). Category I comprised 512 patients with PD-concomitant scoliosis. Thirteen studies reported predictive factors, of which 15 concerned the prevalence of scoliosis in PD patients and 12 Cobb Angle (CA) change after PD correction. Compared with AIS, PD seems to develop earlier in adolescence, and PD with concomitant AIS was more frequently reported in older patients. Evidence remained conflicting regarding the association between the severity of PD and that of scoliosis. As opposed to at a younger age, late PD correction is not associated with a postoperative increase of CA. Limited evidence showed that patients with a high CA undergoing PD correction do not experience an increase in CA, though, strong evidence indicated that it would not lead to a decrease in CA. The mean probable prevalence of AIS in PD patients was 13.1%.

CONCLUSION

Current literature confirms the association between PD and AIS in patients with an indication for PD correction.Level of evidence: III.

The Epidemiology behind Pectus Excavatum: Clinical Study and Review of the Literature

INTRODUCTION

 Pectus excavatum (PE) is a funnel-shaped indentation of the sternum and is the most common deformity of the chest wall. It is associated with syndromic diseases but can occur as an isolated form. Familial occurrence is assumed in up to 40% of cases, but large-scale studies are lacking. Most of the data are obtained from case reports which postulate autosomal recessive, dominant with reduced penetrance, X-linked, and multifactorial patterns of inheritance. No monogenetic cause has been identified to date. This study was designed to provide basic information on the epidemiology, family history, and comorbidity for a large cohort of isolated PE and to show that there is an inheritance pattern for PE that indicates a genetic background.

MATERIALS AND METHODS

 A retrospective study was done using a paper-based questionnaire for all PE patients attending two specialized centers for chest wall deformities. Patients with isolated PE were included and asked to provide information on family history and comorbidities.

RESULTS

 Family history was available for 78 patients. A positive family history was found in 42 patients (54%) with a total of 53 affected family members.

CONCLUSION

 The described family histories indicate an underlying genetic cause for PE. Identification of the genetic factors may contribute to characterize patients who are at risk of inheriting isolated PE.

[Correction of pectus excavatum and long-term outcome in adult]

Pectus excavatum is the most common congenital chest malformation characterized by symmetrical or asymmetric depression of the chest with deformation of the sternocostal complex. Pectus excavatum is often associated with other dysplastic diseases of connective tissue. Ravitch thoracoplasty and Nuss minimally invasive correction are the most common today. The authors report surgical correction of PE in a 50-years-old male who underwent Ravitch modified thoracoplasty with implantation of shape memory plate. Long-term treatment outcomes and technical properties of the plate after removing are analyzed.

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.