The Severity of Pectus Excavatum Defect Is Associated With Impaired Cardiopulmonary Function

Pectus Disorders: Excavatum, Carinatum and Arcuatum

This article reviews pectus excavatum, carinatum, and arcuatum. Topics covered include etiology, epidemiology, associated syndromes, physiologic impact, workup, indications for treatment, surgical and nonsurgical therapy, results, complications, and emerging therapies. Pectus excavatum is an inward deformation of the sternum and/or anterior chest wall. Pectus carinatum is ether an outward protrusion or tilt of the sternum with potential psychological impact, but no demonstrated physiologic impact. Nonoperative compression bracing is successful in carinatum patients with chest wall flexibility who are compliant with a bracing program. Pectus arcuatum is an abnormally short, fully fused sternum with a high anterior protrusion.

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.

(F)utility of preoperative pulmonary function testing in pectus excavatum to assess severity

PURPOSE

The utility of pulmonary function testing (PFT) in pectus excavatum (PE) has been subject to debate. Although some evidence shows improvement from preoperative to postoperative values, the clinical significance is uncertain. A high failure-to-completion rate for operative PFT (48%) was identified in our large institutional cohort. With such a high non-completion rate, we questioned the overall utility of PFT in the preoperative assessment of PE and sought to evaluate if other measures of PE severity or cardiopulmonary function could explain this finding.

METHODS

Demographics, clinical findings, and results from cardiac MRI, PFT (spirometry and plethysmography), and cardiopulmonary exercise tests (CPET) were reviewed in 270 patients with PE evaluated preoperatively between 2015 and 2018. Regression modeling was used to measure associations between PFT completion and cardiopulmonary function.

RESULTS

There were no differences in demographics, symptoms, connective tissue disorders, or multiple indices of pectus severity and cardiac deformation in PFT completers versus non-completers. While regression analysis revealed higher RVEF, LVEF, and LVEF-Z scores, lower RV-ESV/BSA, LV-ESV/BSA, and LV-ESV/BSA-Z scores, and abnormal breathing reserve in PFT completers vs. non-completers, these findings were not consistent across continuous and binary analyses.

CONCLUSIONS

We found that PFT completers were not significantly different from non-completers in most structural and functional measures of pectus deformity and cardiopulmonary function. Inability to complete PFT is not an indicator of pectus severity.

An Aggregate Sternal Force-Deflection Model

Understanding the force-deflection behavior of the sternum is an important element in designing devices for implants for chest wall deformity repair. Human growth and variability makes a single measure of the stiffness difficult to determine. This work takes empirical data from the literature to develop aggregate sternal force-deflection models. Statistical methods were used to determine possible groupings based on patient age and the effect of gender. It was found that three age groups could be used, representing childhood (4-10 years), adolescence (11-19 years), and adulthood (26-53 years). Gender was found to have a statistical p-value of 0.068, 0.0611, and 0.012, respectively, in the proposed age groups. Jittering of the data was used to account for human variability and assumptions made in data comparisons. The jittered results followed that of the initial dataset. Childhood force-deflection behavior follows a relatively constant stiffness, adolescence experiences a growth period of increasing stiffness, and adulthood stiffnesses again begin to stabilize around a relatively constant value.

Description of a new clinical syndrome: thoracic constriction without evidence of the typical funnel-shaped depression-the "invisible" pectus excavatum

Pectus excavatum (PE) is a congenital malformation with a funnel-shaped depression of the sternum that can lead to cardiac symptoms. However, there are patients with thoracic constriction (defined as elevated Haller-Index > 3.25 determined by cardiac magnetic resonance imaging (CMR)) without visible evidence of PE, leading to similar complaints. Between January 2004 till June 2020, patients who underwent CMR for further evaluation of the heart, due to cardiac symptoms were enrolled and compared to controls. Biventricular global strain analysis was assessed using feature tracking (CMR-FT). ECG and/or Holter recordings were performed to detect rhythm events. Cardiac symptoms were evaluated in detail using a questionnaire. Finally, 88 patients (male 35, female 53) with elevated Haller-Index (3.9 ± 0.8) were included and compared to CMR data from 25 individuals with confirmed PE and 25 healthy controls (HC). Mean age at time of CMR was 35 ± 16 years. The most common symptoms at presentation were palpitations (41%), followed by dyspnea (24%) and atypical chest pain (14%). Three patients (3%) had atrial fibrillation or atrial flutter. Concomitant phenomena were pericardial effusion in 39% and mitral valve prolapse (MVP) in 27% of the study cohort. While there were no differences in left ventricular function or volumes, right ventricular function (RVEF) was significantly lower in patients with internal PE compared to HC (RVEF (%) 50 ± 5 vs 59 ± 4, p < 0.01). Strain analysis revealed only discrete changes in RV strain, implying a purely mechanical problem in the absence of structural changes. RV dimensions were negatively correlated with the size of thoracic indices (r = 0.41), reflecting the extent of thoracic constriction. MVP was more prevalent in patients with greater thoracic indices (r = 0.24). The described cohort, referred to as internal PE because of the absence of external changes, showed similar CMR morphologic findings as patients with real PE (especially altered dimensions of the right heart and a lower RVEF). In addition, there was a high incidence of rhythm disturbances, such as extrasystoles or arrhythmias. In one-third of the study cohort additional abnormalities such as pericardial effusion or MVP were present, with MVP being found more frequently in patients with larger thoracic indices, suggesting a possible common pathogenesis.Trial registration: ISRCTN registry, ISRCTN15355937, retrospectively registered 03.06.2022, https://www.isrctn.com/ISRCTN15355937?q=15355937&filters=&sort=&offset=1&totalResults=1&page=1&pageSize=10 .

Modified bar bending method of thoracoscopic nuss procedure on pectus excavatum: a retrospective single-center study

BACKGROUND

Pectus excavatum (PE) is the most common disease of chest wall deformity, with an incidence of 1 in 300-400 births. Nuss procedure has proved to be the best surgical treatment method and has been widely used after clinical use for 30 years. We aimed to review the clinical data of pectus excavatum (PE) of thoracoscopic Nuss procedure adopted the Modified bar bending method of the six-point seven-section type, and compare it with the traditional curved bar bending method to explore the clinical application effect.

METHODS

Forty-six cases of clinical data were summarized of children with PE who adopted the treatment of the Modified bar bending method of the six-point seven-section type from January 2019 to December 2021, and 51 cases were compared of PE children who adopted the treatment of traditional curved bar bending method from January 2016 to December 2018, including the data of age, gender, preoperative symptoms, symmetry, Haller index, operation time, bar bending time, intraoperative bleeding, postoperative complications, bar migration, postoperative effect evaluation, etc. RESULTS: The Procedure duration (P = 0.008), bar bending time (P < 0.001), and duration of postoperative pain (P < 0.001) were reduced significantly, and the incidence of bar migration after surgery was reduced as well by the modified bar bending method. There was no difference compared with traditional Nuss produce, like the incidence of evaluation of postoperative effects (Excellent, P = 0.93; Good, P = 0.80; Medium, P = 1.00; Poor, P = 1.00), bar migration (P = 1.00), postoperative complications (P = 1.00), Clavien- Dindo classification of surgical complications (I = 0.165; II = 1.00; IIIa = 1.00; IIIb = 1.00; VI = 1.00; V = 1.00), operative safety, and operative validity.

CONCLUSION

Modified bar bending method of the six-point seven-section type, which is a kind of surgical method worth applying and popularizing, and the advantages of minimally procedure duration, bar bending time, and duration of postoperative pain, compared with the traditional bar bending method.

Evaluating Cardiac Lateralization by MRI to Simplify Estimation of Cardiopulmonary Impairment in Pectus Excavatum

BACKGROUND

The severity of pectus excavatum is classified by the Haller Index (HI) and/or Correction Index (CI). These indices measure only the depth of the defect and, therefore, impede a precise estimation of the actual cardiopulmonary impairment. We aimed to evaluate the MRI-derived cardiac lateralization to improve the estimation of cardiopulmonary impairment in Pectus excavatum in connection with the Haller and Correction Indices.

METHODS

This retrospective cohort study included a total of 113 patients (mean age = 19.03 ± 7.8) with pectus excavatum, whose diagnosis was verified on cross-sectional MRI images using the HI and CI. For the development of an improved HI and CI index, the patients underwent cardiopulmonary exercise testing to assess the influence of the right ventricle's position on cardiopulmonary impairment. The indexed lateral position of the pulmonary valve was utilized as a surrogate parameter for right ventricle localization.

RESULTS

In patients with PE, the heart's lateralization significantly correlated with the severity of pectus excavatum (p ≤ 0.001). When modifying HI and CI for the individual's pulmonary valve position, those indices are present with greater sensitivity and specificity regarding the maximum oxygen-pulse as a pathophysiological correlate of reduced cardiac function (χ² 10.986 and 15.862, respectively).

CONCLUSION

The indexed lateral deviation of the pulmonary valve seems to be a valuable cofactor for HI and CI, allowing for an improved description of cardiopulmonary impairment in PE patients.

Academic performance in children with pectus excavatum: a real-world research with propensity score matching

BACKGROUND

The optimal timing of surgery for pectus excavatum (PE) is controversial. A large proportion of children will not undergo surgery before puberty. However, untimely surgery may lead to a decline in the children's social adaptation and competitiveness because the children have already developed psychological and physiological impairments due to PE at an early age. The study retrospectively compared the academic performance in PE children undergoing the Nuss procedure versus nonsurgical observation.

METHODS

This retrospective real-world research study included 480 PE patients with definite surgical indications, in whom it was first recommended that they undergo surgery between the ages of 6 and 12 years old. Academic performance was collected at baseline and 6 years later. A generalized linear regression was calculated to screen the factors affecting the performance. A propensity score matching (PSM) analysis was conducted to reduce the potential for confounding factors between surgical and nonsurgical PE patients.

RESULTS

Haller index (HI) and pulmonary function were recognized as factors affecting baseline performance according to the generalized linear regression. For PE children with surgical indications, their academic performance significantly declined after 6 years of nonsurgical observation (52.1% ± 17.1% versus 58.3% ± 16.7%, p = 0.042). The academic performance in the surgery group was better than that in the nonsurgery group 6 years after PSM (60.7% ± 17.7% versus 52.1% ± 17.1%, p = 0.008).

CONCLUSIONS

The severity of PE will affect the academic performance of children.For PE children with definite surgical indications between the ages of 6 and 12 years old, surgical intervention rather than nonsurgical observation is more conducive to the development of children's academic performance.

Does age matter? Cardiopulmonary profiles of adolescents versus adults with pectus excavatum presenting for surgical evaluation

PURPOSE

We sought to analyze differences in presentation and cardiopulmonary function between those referred for surgical consultation as adolescents (11-17 years) versus adults (18 + years).

METHODS

Presenting symptoms, past medical history, and results from cardiac MRI (CMR), pulmonary function testing (PFT), and cardiopulmonary exercise testing (CPET) were reviewed in 329 patients evaluated preoperatively between 2015 and 2018. Adjusted regression modeling was used to measure associations between pectus indices and clinical endpoints of cardiopulmonary function.

RESULTS

Our sample included 276 adolescents and 53 adults. Adults presented more frequently with chest pain (57% vs. 38%, p = 0.01), shortness of breath (76% vs. 59%, p = 0.02), palpitations (21% vs. 11%, p = 0.04), and exercise intolerance (76% vs. 59%, p = 0.02). Their Haller indices (5.2 [4.2, 7.0] vs. 4.7 [4.0, 5.7], p = 0.05) and cardiac asymmetry (1.8 [0.5] vs. 1.6 [0.5], p = 0.02) were also higher. In continuous outcome analysis, adolescents had higher FEV1/FVC on PFT and higher work on CPET (p < 0.01).

CONCLUSIONS

Adults with pectus excavatum were more symptomatic than adolescents with deeper, more asymmetric deformities, decreased FEV1/FVC and exercise capacity. These findings may support earlier versus later repair to prevent age-related decline. Further studies are warranted.

The Safety and Efficacy of the Modified Single Incision Non-thoracoscopic Nuss Procedure for Children With Pectus Excavatum

BACKGROUND

This study described and evaluated the safety and efficacy of a modified single incision non-thoracoscopic Nuss procedure in pectus excavatum (PE) children.

METHODS

PE patients undergoing the non-thoracoscopic Nuss procedure at the Children's Hospital of Chongqing Medical University between January 2017 and December 2020 were retrospectively enrolled. The patients were divided into two groups according to operation procedures: the double incision Nuss (DN) group and the modified single incision Nuss (SN) group. Propensity score matching (PSM) was applied before evaluation of operative and postoperative characteristics to reduce selection bias.

RESULTS

Of the 502 patients included, 261 were enrolled in the DN group, and 241 in the SN group. The operation time [35.0 (30.0-40.0) vs. 50.0 (40.0-55.0) minutes, P < 0.001] and postoperative inpatient stay [7.0 (6.0-8.0) vs. 7.0 (7.0-8.0) days, P < 0.001] of the patients in the SN group after PSM were significantly shorter than those of the patients in the DN group after PSM. Moreover, median blood loss was significantly less in the SN group after PSM than that in the DN group after PSM [2.0 (1.0-5.0) vs. 5.0 (2.0-5.0) ml, P < 0.001]. There were no significant differences in the incidence of complications between the two groups (P > 0.05). Bar removal was performed in 85 patients in the SN group within 24-42 months after surgery. Additionally, the SN group patients had a significantly lower Haller index (HI) after bar removal [2.36 (2.15-2.55) vs. 3.76 (3.18-4.26), P < 0.001] compared to the initial HI.

CONCLUSIONS

The modified procedure is safe and effective for children with PE and is worthy of clinical application.