Pectus excavatum: historical background, clinical picture, preoperative evaluation and criteria for operation

Effect of Narrow Chest on Minimally Invasive Mitral Valve Surgery via Right Minithoracotomy

BACKGROUND

The effect of a narrow chest on minimally invasive mitral valve surgery (MIMVS) is unclear.

METHODS AND RESULTS

We enrolled 206 MIMVS patients and measured anteroposterior diameter (APD) between the sternum and vertebra, transverse thoracic diameter (TD), right and left APD of the hemithorax (RD and LD, respectively), and the Haller index (HI; TD/APD ratio) on computed tomography. Preoperative characteristics and operative outcomes were compared between patients with a narrow chest (Group N; HI >2.5; n=53) and those with a normal chest (control [C]; HI ≤2.5; n=153), and the correlations of these measurements with operation time were evaluated in 133 patients undergoing an isolated mitral procedure. Groups N and C differed significantly in APD (89.4 vs. 114.3 mm, respectively; P<0.001), TD (251.5 vs. 240.3 mm, respectively; P=0.002), RD (152.5 vs. 172.5 mm, respectively; P<0.001), LD (155.0 vs. 172.4 mm, respectively; P<0.001), and HI (2.84 vs. 2.12, respectively; P<0.001). Procedural characteristics were comparable, except for a longer aortic cross-clamp time (ACCT) in Group N (118.7 vs. 105.8 min; P=0.047). Rates of surgical death, re-exploration, cerebral infarction, and prolonged ventilation were comparable between the 2 groups. TD was significantly correlated with ACCT (R2=0.037, P=0.028) in patients undergoing an isolated mitral procedure.

CONCLUSIONS

Early MIMVS outcomes in patients with narrow chests are satisfactory. TD prolongs ACCT during MIMVS.

Long term results in children underwent nuss procedure preschool with pectus excavatum: Real-world study with propensity matching

Background

It is controversial when surgery should be performed for pectus excavatum (PE). The study retrospectively compared the long-term prognosis in PE children undergoing the Nuss procedure at the age of 4-6 versus those performing surgery at the age of 12-14.

Methods

178 patients were included in the retrospective real-world research. Clinical Characteristics were collected at baseline. The endpoint of the study was set as the last follow-up at the age of 18 in outpatient services. Satisfaction and complication rate were set as the primary outcome and were collected at the endpoint. Hospital stay post-surgery and analgesia dosage were regard as the secondary outcome. To reduce potential bias between two different age groups, propensity score matching (PSM) analysis was analysized.

Results

The oral analgesic dosage of children in the 4-6 years old age group is significantly lower than that of the 12-14 years old group (0.70/kg, 0.30-1.50/kg versus 1.50/kg, 0.90-2.30/kg, P < 0.001), and children in the younger age group are discharged earlier. There was no difference in overall satisfaction (89.1 %, versus 88.20 %, P = 0.99) and recurrence rate (7.2 %, versus 6.8 %, P = 0.99) between the two groups of when they reach the age of 18.

Conclusions

Performing Nuss procedure at the age of 4-6 does not affect the overall long-term satisfaction of the child or increase the long-term recurrence rate. Surgical intervention in children with pectus excavatum preschool can provide a better postoperative experience in hospital compared with intervention in adolescent.

Questionnaire-based subjective evaluation and analysis of factors influencing the effectiveness of treatment with the vacuum bell in children with pectus excavatum: a cross-sectional observational study

Background

Vacuum bell (VB) is a technique to treat pectus excavatum in children. Its effectiveness and influencing factors, however, remain under investigated. The aim of this study was to examine the therapeutic effect and its influencing factors of VB in children with pectus excavatum.

Methods

A cross-sectional observational study was conducted. Parents of children with pectus excavatum who underwent treatment with a VB between January 2018 and December 2019 were recruited. A survey was designed based on previously related studies and delivered to the parents in September-October 2021. The therapeutic effect was analyzed using subjective experiences by parents. Factors related to effectiveness were analyzed through univariate analysis and multivariate logistic regression.

Results

Of the 77 surveys distributed, 65 (84%) were returned. The mean duration of VB was 23.20 (SD 9.86) months. Caregivers rated the effect of VB treatment as moderate (41.5%), good (46.2%), excellent (12.3%). There were 39 children (60%) who had at least one pause of using VB for more than two weeks. Univariate analysis showed no significant difference between age, height, weight, duration of VB (months) and the effectiveness of VB therapy as defined by caregivers (p > 0.05) and significant difference were observed of the variables "complication of petechiae" (p = 0.034) and "device returned to manufacturer for repair" (p = 0.011). The multivariate logistic regression showed that the occurrence of complication petechiae (p = 0.046) was an influential factor for the effectiveness of VB.

Conclusions

The evaluations reported by the parents suggested that the VB treatment was effective, although with varying degrees. The complication of petechiae seems an influencing factor to successful VB treatment in children with pectus excavatum. Further studies are needed to assess the long-term outcome and effect of VB and to improve the device and to reduce complications in order to enhance compliance and improve effectiveness.

'Short Bars Crossed' to Remodel the Entire Chest Wall in Children and Adolescents with Pectus Excavatum

BACKGROUND

The cross-bar technique of minimally invasive pectus excavatum (PE) correction remains underreported, which is especially true of pediatric patients. We therefore reviewed the experience of a Turkish and an Austrian center. An additional novelty characterizing both pediatric cohorts was the use of short bars.

METHODS

In a retrospective study, pediatric PE corrections involving 'short bars crossed' were analyzed for complications and intra-/postoperative outcomes. Cases with two or three bars were included, given that a horizontal third bar was placed whenever considered useful for upper-chest elevation. All bars were fitted with a single stabilizer near the surgical entry point. In the Austrian center, intercostal nerve cryoablation was used for pain management. Descriptive statistics are presented.

RESULTS

Seventy-eight patients ≤18 years old were evaluable at the Turkish (n = 56) and Austrian (n = 22) centers. Total median values were 16.2 (IQR: 15.1-17.4) years for age and 4.60 (IQR: 3.50-6.11) for Haller index. Ten mild or moderate complications (12.8%) were observed, including just one revision requirement due to bar migration (1.28%). Intercostal nerve cryoablation (n = 13) was associated with longer surgical procedures at 150 (IQR: 137-171) versus 80 (IQR: 60-100) minutes but with shorter hospital stays, given an IQR of 3-4 days versus 4-5 days.

CONCLUSION

'Short bars crossed'-with a single stabilizer in a ventral position close to the surgical entry point-ensure a wide distribution of forces, protect against bar migration, are safe and effective, and offer stability at an age characterized by growth and physical activity.

LEVEL OF EVIDENCE

IV.

Utility of White Light Scanning as an Alternative to Computed Tomography to Evaluate Severity of Pectus Excavatum Deformity

BACKGROUND

Pectus excavatum (PE) severity and surgical candidacy are determined by computed tomography (CT)-delineated Haller Index (HI) and Correction Index (CI). White light scanning (WLS) has been proposed as a non-ionizing alternative. The purpose of this retrospective study is to create models to determine PE severity using WLS as a non-ionizing alternative to CT.

METHODS

Between November 2015 and February 2023, CT and WLS were performed for children ≤18 years undergoing evaluation at a high-volume, chest-wall deformity clinic. Separate quadratic discriminate analysis models were developed to predict CT HI ≥ 3.25 and CT CI ≥ 28% indicating surgical candidacy. Two bootstrap forest models were trained on WLS measurements and patient demographics to predict CT HI and CT CI values then compared to actual index values by intraclass correlation coefficient (ICC).

RESULTS

In total, 242 patients were enrolled (86.4% male, mean [SD] age 15.2 [1.3] years). Quadratic discriminate analysis models predicted CT HI ≥ 3.25 with specificity = 91.7%, PPV = 97.7% (AUC = 0.91), and CT CI ≥ 28% with specificity = 92.3%, PPV = 93.5% (AUC = 0.84). Bootstrap forest model predicted CT HI with training dataset ICC (95% CI) = 0.91 (0.88-0.93, R2 = 0.85) and test dataset ICC (95% CI) = 0.86 (0.71-0.94, R2 = 0.77). For CT CI, training dataset ICC (95% CI) = 0.91 (0.81-0.93, R2 = 0.86) and test dataset ICC (95% CI) = 0.75 (0.50-0.88, R2 = 0.63).

CONCLUSIONS

Using noninvasive and nonionizing WLS imaging, we can predict PE severity at surgical threshold with high specificity obviating the need for CT. Furthermore, we can predict actual CT HI and CI with moderate-excellent reliability. We anticipate this point-of-care tool to obviate the need for most cross-sectional imaging during surgical evaluation of PE.

LEVEL OF EVIDENCE

Level III.

STUDY TYPE

Study of Diagnostic Test.

Is chest radiography a valid alternative to computed tomography in evaluation of pectus excavatum?

BACKGROUND

Current pectus excavatum management includes a computed tomography scan to evaluate the correction index, whose superiority to the Haller Index in terms of specificity and sensibility is still under debate. Furthermore, several studies report interchangeability between the Haller Index as measured by computed tomography and as measured by X-radiograph; however, it is not clear whether this correlation also exists for the correction index. The aim of our study was to evaluate the correlation between measurements of the Haller Index and the correction index obtained by Computed Tomography and by X-radiograph.

METHODS

This prospective study included 31 patients with pectus excavatum (who underwent preoperative chest computed tomography and X-radiograph) and a control group of 31 patients (who presented no chest deformity and underwent the same exams for other unrelated causes). We measured Haller Index and correction index on both exams for both groups. To demonstrate any correlation between computed tomography scans and X-radiographs for the two indexes, the Pearson R correlation test, Bland-Altman analysis, and ANOVA nested test were performed.

RESULTS

Pearson's coefficient (0.829 with P<0.0001) and ANOVA nested test showed a significant correlation and similar results between the Haller Index and the correction index on computed tomography and on X-radiograph.

CONCLUSIONS

Significant correlation and similar results are shown in our study in the measurement of CI and HI on computed tomography and X-radiograph. Further studies including a larger number of patients may be warranted.

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

BACKGROUND

Usually, pectus bars are removed 3 years after the Nuss procedure in patients with pectus excavatum. However, the optimal timing for postoperative pectus bar removal remains undefined. Our study investigated the effects of delayed pectus bar removal after Nuss repairs.

METHODS

Retrospective data were collected on patients who underwent Nuss procedures for pectus excavatum and had their bars removed from August 2014 to December 2020. Patients with correction periods > 3 years were divided into group A (< 6 years) and group B (≥ 6 years). Propensity score matching was used to compare complications and radiological outcomes associated with bar removal.

RESULTS

Of the 542 patients who underwent bar removal, 451 (Group A: 419 patients, Group B: 32) had correction duration > 3 years. The average correction duration was 4.5 ± 1.4 years. After propensity score matching analysis, group B [median duration: 8.0 (6.0-16.2) years] exhibited significantly longer median operative times (85 vs. 55 min; P = 0.026), higher callus formation rates (68.8% vs. 46.9%; P = 0.029), and greater median intraoperative blood loss (35 vs. 10 mL; P = 0.017) than group A [median duration: 4.2 (3.0-5.9) years]. However, following bar removal, the groups showed no statistical differences in the surgical complication rates (group A: 6.3% vs. group B: 9.4%; P = 0.648) or median ratio of radiological improvement (an improvement on the Haller index on chest radiography; 21.0% vs. 22.2%; P = 0.308).

CONCLUSIONS

Delaying pectus bar removal after Nuss repair presents certain challenges but does not compromise overall outcomes. These findings suggest that a longer correction period may be unnecessary. However, further multicenter studies with long-term follow-up are warranted to assess long-term outcomes.

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

BACKGROUND

Pectus excavatum (PE) is the most common congenital abnormality of the chest wall. Most patients with PE have slim bodies. Some studies have been conducted on the physical growth of children and adolescents who underwent the Nuss procedure. This study aimed to evaluate body measurement changes in adult patients with PE after the Nuss procedure.

METHODS

A total of 272 adult PE patients, who underwent the Nuss procedure and pectus bars removal from August 2014 to December 2020, were evaluated retrospectively. Body measurement [body height (BH), body weight (BW), and body mass index (BMI)] of the patients were collected before Nuss repair and after bar removal. We used the interquartile range (IQR) to identify and exclude outliers. Associations between changes in body measurement and clinical and radiological features were evaluated.

RESULTS

The BH, BW and BMI showed significantly increased after pectus bar removal, compared to pre-Nuss procedure parameters (BH 173.8 ± 5.9 cm vs. 173.9 ± 5.9 cm, P < 0.001; BW 60.3 ± 8.1 kg vs. 61.1 ± 8.8 kg, P = 0.005; BMI 19.9 ± 2.2 kg/m2 vs. 20.1 ± 2.4 kg/m2, P = 0.02). The same result were observed in the male subgroup, the HI ≥ 4 group and the male subgroup within the HI ≥ 4 group.

CONCLUSIONS

The BH, BW and BMI were significantly increased after completing surgical correction of PE using the Nuss procedure, particularly in young males and patients with more pronounced deformities.

The effect of surgical repair of the chest on postural stability among patients with pectus excavatum

Pectus excavatum is the most encountered of chest wall deformities. It may produce respiratory and cardiovascular symptoms, hence surgical repair of this defect is performed. The procedure involving the insertion of metal bars under the sternum (the Nuss procedure) usually brings significant improvement to patients. However, the effect of the repair on the postural stability of patients has not been studied so far. To investigate the problem of patients' stability in the postoperative period male patients with pectus excavatum (n = 21) and healthy controls (n = 22) were included in the study. Using posturography methods, we showed a negative impact of the pectus excavatum repair surgery on patients' postural stability in the first postoperative phase. The centre of pressure displacement parameters used to measure postural stability were lower after the repair for both, the frontal and sagittal plane as well as for the velocity of displacements in the sagittal plane in the double stance with eyes open. Poorer postural stability was also found in patients with pectus excavatum when compared to healthy controls. Our findings may be useful for functional monitoring in the evaluation and surgical management of pectus excavatum patients and also when designing the rehabilitation of patients undergoing the Nuss procedure.

Overview of chest wall deformities

Chest wall deformities are congenital disorders characterized by abnormal development and appearance of the thoracic wall. The most common form is the pectus excavatum deformity, known as shoemaker's chest. Pectus carinatum, known as pigeon chest, is the second most common deformity. In general, most patients are asymptomatic, but cardiopulmonary problems may accompany the disease. The indication for treatment is mostly cosmetic. Treating patients before they reach adulthood increases the chance of success. Surgical treatment can be open or minimally invasive.

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 .

Pectus Excavatum: Consensus and Controversies in Clinical Practice

BACKGROUND

Pectus excavatum is the most common congenital anterior chest wall deformity. Currently, a wide variety of diagnostic protocols and criteria for corrective surgery are being used. Their use is predominantly based on local preferences and experience. To date, no guideline is available, introducing heterogeneity of care as observed in current daily practice. The aim of this study was to evaluate consensus and controversies regarding the diagnostic protocol, indications for surgical correction, and postoperative evaluation of pectus excavatum.

METHODS

The study consisted of 3 consecutive survey rounds evaluating agreement on different statements regarding pectus excavatum care. Consensus was achieved if at least 70% of participants provided a concurring opinion.

RESULTS

All 3 rounds were completed by 57 participants (18% response rate). Consensus was achieved on 18 of 62 statements (29%). Regarding the diagnostic protocol, participants agreed to routinely include conventional photography. In the presence of cardiac impairment, electrocardiography and echocardiography were indicated. Upon suspicion of pulmonary impairment, spirometry was recommended. In addition, consensus was reached on the indications for corrective surgery, including symptomatic pectus excavatum and progression. Participants moreover agreed that a plain chest radiograph must be acquired directly after surgery, whereas conventional photography and physical examination should both be part of routine postoperative follow-up.

CONCLUSIONS

Through a multiround survey, international consensus was formed on multiple topics to aid standardization of pectus excavatum care.

Two Types of Management for the Noninvasive Treatment of Pectus Excavatum in Neonatal Puppies-Case Reports

Pectus excavatum is a deformity of the thorax characterized by ventrodorsal narrowing of the sternum bone and costal cartilages, which can lead to compression and cardiopulmonary alterations in dogs, presenting a high prevalence in brachycephalic breeds. The aim of this report was to describe two types of management for the noninvasive treatment of pectus excavatum in newborn puppies of the breeds French Bulldog and American Bully. The puppies presented dyspnea, cyanosis and substernal retraction during inspiration. The diagnosis was performed by physical examination and confirmed by chest X-ray. Two types of splints were performed (a circular splint with plastic pipe and a paper box splint on the chest), aiming at thoracic lateral compression and frontal chest remodeling. The management was effective for the conservative treatment of mild-grade pectus excavatum, resulting in the repositioning of the thorax and improvement of the respiratory pattern.

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.

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.

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.

Development of Prediction Models for Cardiac Compression in Pectus Excavatum Based on Three-Dimensional Surface Images

In pectus excavatum, three-dimensional (3D) surface imaging provides an accurate and radiation-free alternative to computed tomography (CT) to determine severity. Yet, it does not allow for cardiac evaluation since 3D imaging solely captures the chest wall surface. The objective was to develop a 3D image-based prediction model for cardiac compression in patients evaluated for pectus excavatum. A prospective cohort study was conducted including consecutive patients referred for pectus excavatum who received a thoracic CT. Additionally, 3D images were acquired. The external pectus depth, its length, craniocaudal position, cranial slope, asymmetry, anteroposterior distance and chest width were calculated from 3D images. Together with baseline patient characteristics they were submitted to forward multivariable logistic regression to identify predictors for cardiac compression. Cardiac compression on CT was used as reference. The model's performance was depicted by the area under the receiver operating characteristic (AUROC) curve. Internal validation was performed using bootstrapping. Sixty-one patients were included of whom 41 had cardiac compression on CT. A combination of the 3D image derived external pectus depth and external anteroposterior distance was identified as predictive for cardiac compression, yielding an AUROC of 0.935 (95% confidence interval [CI]: 0.878-0.992) with an optimism of 0.006. In a second model for males alone, solely the external pectus depth was identified as predictor, yielding an AUROC of 0.947 (95% CI: 0.892-1.000) with an optimism of 0.0002. We have developed two 3D image-based prediction models for cardiac compression in patients evaluated for pectus excavatum which provide an outstanding discriminatory performance between the presence and absence of cardiac compression with negligible optimism.

Patient-Controlled Intravenous Analgesia with or without Ultrasound-Guided Bilateral Intercostal Nerve Blocks in Children Undergoing the Nuss Procedure: A Randomized, Double-Blinded, Controlled Trial

Background

Two analgesic strategies have been described for pain treatment after the pectus excavatum surgery: the patient-controlled intravenous analgesia (PCIA) and ultrasound-guided intercostal nerve block. In this prospective, randomized and double-blinded trial and the short and long-term outcomes were compared in patients after surgery.

Methods

The children were randomized to either the intercostal or control group. Ultrasound-guided intercostal nerve block was with 0.25% ropivacaine and 5 mg dexamethasone in the intercostal group, while the control group was with 0.9% normal saline. The block was performed in the intercostal space corresponding to the lowest depression of the sternum and repeated bilaterally in the spaces above and below. Postoperatively, the children in the two-groups received PCIA with fentanyl for 48 hours. The primary outcome was a pain score on the postoperative day 1, as measured by the Visual Analogue Scale (VAS).

Results

Sixty children undergoing the Nuss procedure were enrolled in the trial. The mean differences in VAS scores between the two groups were 3.2 in the PACU (p < 0.001), 1.7 on postoperative day 1 (p < 0.001) and 0.7 on postoperative day 2 (p=0.015). The opioid consumption was significantly lower in the intercostal group during the postoperative 48 hours (p < 0.05). The anxiety and QOL scores in the intercostal group were significantly improved on some points of time (p < 0.05). The incidence of adverse events was markedly lower in the intercostal group during the postoperative 48 hours (p < 0.05).

Conclusions

Our results suggest ultrasound-guided intercostal nerve block with PCIA may be more effective than PCIA alone in children who underwent the Nuss procedure.

Pectus excavatum, kyphoscoliosis associated with thoracolumbar spinal stenosis: a rare case report and literature review

Background

Pectus excavatum is the most common congenital chest wall defect. Thoracolumbar spinal stenosis and kyphoscoliosis was seen in patients with pectus excavatum. It can be caused by ossification of the ligamentum flavum, which is rare in patients with pectus excavatum.

Case presentation

We reported a 26-year-old woman presented bilateral lower extremities weakness and numbness for two months, progressive worsening. She was diagnosed as thoracolumbar spinal stenosis with ossification of the ligamentum flavum, thoracolumbar kyphoscoliosis associated with pectus excavatum. The posterior instrumentation, decompression with laminectomy, and de-kyposis procedure with multilevel ponte osteotomy were performed. Her postoperative course was uneventful and followed up regularly. Good neurologic symptoms improvement and spinal alignment were achieved.

Conclusions

Pectus excavatum, kyphoscoliosis associated with thoracolumbar spinal stenosis is rare, and thus her treatment options are very challengeable. Extensive laminectomy decompression and de-kyphosis procedures can achieve good improvement of neurologic impingement and spinal alignment.

Nuss Technique for Pectus Excavatum in Adult Patients: Cosmetic Satisfaction and Improvement of Quality of Life in a Single-Center Experience

Objectives

Since its introduction, the Nuss minimally invasive procedure for pectus excavatum (PE) repair (MIRPE) has become the method of choice. The current study describes our experience of PE correction in adults, with particular focus on postoperative outcomes, pain, quality of life, and patients’ satisfaction.

Methods

We enrolled for this observational study n = 93 adult patients from 2011 to 2018. The Haller index was used to quantify PE severity. Pulmonary function tests and cardiac examinations were performed preoperatively; we developed a standardized surgical technique and postoperative treatment, including follow-up at 3, 12, and 24 months after surgery and 6 months after bar removal. We also evaluated the quality of life and the satisfaction with the cosmetic result after the procedure with standardized questionnaires.

Results

No operative or perioperative deaths occurred nor life-treating complications. Thirteen complications occurred in 12 patients, with a total complication rate of 14% (n = 13/93). Pain intensity decreased in the follow-up [pain score visual analog scale at 3 months: median 1 (0–8); 12 months: median 1 (0–5); and 24 months: median 1 (0–4)]. Better or much better quality of life after the Nuss procedure was observed: n = 79 (84.1%) at 3 months, n = 80 (86%) at 12 months, and n = 85 (91.4%) at 24 months. After 2 years of observation, more than 90% of patients described improvement in their quality of life and satisfaction with the cosmetic results. Only a very small group of patients suffered from pain in the follow-up.

Conclusion

Our results demonstrate that the MIRPE procedure is safe and can be performed with excellent results in adults both for improvement of quality of life and for satisfaction with cosmetic results.

Postoperative management of pediatric patients undergoing minimally invasive repair of pectus excavatum: Where are we now?

PURPOSE

Minimally invasive repair of pectus excavatum (MIRPE) often leads to a painful and challenging recovery period. This study aims to describe the postoperative management of pediatric patients undergoing MIRPE and compare postoperative outcomes between patients using different routes of postoperative analgesia.

METHODS

Retrospective chart review of pediatric patients who underwent MIRPE from July 2003 to September 2019 at a single pediatric tertiary care center. Data on pain management and course of hospital stay were ascertained. Descriptive statistics, Mann-Whitney U and Pearson Chi-Square tests were used to analyze data. A p-value <0.05 was considered significant.

RESULTS

Of the 115 patients identified, 58 (50.4%) managed pain postoperatively using thoracic epidural and 57 (49.6%) used intravenous patient-controlled analgesia (IVPCA). The transition from the predominant use of epidural to IVPCA for MIRPE occurred between 2012 and 2013. Higher pain scores were reported by the IVPCA group at 6 h (p<0.001) and 12 h (p<0.001) postoperative. Patients using IVPCA had lower postoperative opioid consumption (p<0.001) and switched to oral opioids sooner than the epidural group (p<0.001). Fewer patients in the IVPCA group required urinary catheterization (p<0.001). Patients using IVPCA had a shorter hospital stay (4 days [IQR 4-5]) compared to the epidural group (5.5 [IQR 5-6]; p<0.001). Readmission was comparable at 3.48% in the total sample.

CONCLUSION

Patients using intravenous patient-controlled analgesia reported higher pain scores however, this route of analgesia was associated with shorter hospital stay. Prospective studies designed to address moderator variables are required to confirm findings and develop standardized recovery protocols.

Current Development of Minimally Invasive Repair of Pectus Excavatum (MIRPE)

For decades, open surgical repair was the only available method to treat congenital and acquired chest wall deformities (CWDs). In 1998, D. Nuss described a minimally invasive procedure for surgical repair of Pectus excavatum (PE). Today, the Nuss procedure is performed with increasing frequency worldwide and considered as the “gold standard”. After its introduction, the method experienced numerous modifications such as routine thoracoscopy and/or sternal elevation, increasing safety of the procedure. Placement of multiple bars and/or the so called cross-bar technique were introduced to correct complex CWDs. Standardized pain management, the introduction of cryo-analgesia and a standardized postoperative physiotherapy program including deep breathing exercises facilitate the establishment of an enhanced recovery after surgery (ERAS) process. However, the widespread use of the minimally invasive repair of pectus excavatum (MIRPE) procedure has been associated with a significant number of serious complications. Furthermore, several studies report near-fatal complications, not only during bar placement, but also during bar removal. This review focuses upon the most relevant modifications, including recent published surgical techniques of MIRPE, in order to describe current developments in the field.

Pulmonary function, exercise capacity and dyspnea in patients 7 ​years after Nuss surgery

PURPOSE

Pectus excavatum is a frequent thoracic malformation increasingly treated with minimally invasive methods (MIRPE), which are performed for cardio-respiratory problems and in some centers also for esthetic considerations. Theoretically, MIRPE may increase thoracic elastic recoil, work of breathing and cause emphysema. The aim of the present study was to determine whether teenagers who underwent MIRPE may expect normal thoracic cage development, cardio-respiratory function, exercise capacity and asymptomatic functioning.

MATERIAL AND METHODS

Fifty five patients (21.1 ​± ​3.0 years) who underwent MIRPE between 2000 and 2010 were assessed 6.8 (±2.4) years after surgery. Controls were matched for sex, age and height to the intervention participants. Spirometry, body plethysmography, diffusion capacity and the 6 ​min walking test (6MWT) were performed. Anteroposterior (AP) and transverse chest diameters were measured.

RESULTS

Participants who underwent MIRPE had normal pulmonary function, and exercise capacity. After adjustment for potential confounders, the intervention group had lower mean BMI [-1.88 ​± ​0.56 (kg/m²); p ​= ​0.001] and chest AP diameter [-2.79 ​± ​0.57 (cm); p ​< ​0.001], but higher residual volume (RV%) [12.98 ​± ​5.31 (%); p ​= ​0.001], RV% total lung capacity (TLC) [5.56 ​± ​0.92 (%); p ​< ​0.001], forced expiratory volume in 1 ​s/forced vital capacity (FEV₁/FVC) [2.64 ​± ​1.28 (%); p ​= ​0.039] and 6MWT distance [29.10 ​± ​13.02 (m); p ​= ​0.025].

CONCLUSIONS

Young adults who undergo MIRPE may expect normal pulmonary function and exercise capacity. Observed differences in air trapping require further assessment in terms of emphysema development risk.

Visual diagnosis of pectus excavatum: An inter-observer and intra-observer agreement analysis

BACKGROUND/PURPOSE

Among patients suspected of pectus excavatum, visual examination is a key aspect of diagnosis and, moreover, guides work-up and treatment strategy. This study evaluated the inter-observer and intra-observer agreement of visual examination and diagnosis of pectus excavatum among experts.

METHODS

Three-dimensional surface images of consecutive patients suspected of pectus excavatum were reviewed in a multi-center setting. Interactive three-dimensional images were evaluated for the presence of pectus excavatum, asymmetry, flaring, depth of deformity, cranial onset, overall severity and morphological subtype through a questionnaire. Observers were blinded to all clinical patient information, completing the questionnaire twice per subject. Agreement was analyzed by kappa statistics.

RESULTS

Fifty-eight subjects with a median age of 15.5 years (interquartile range: 14.1-18.2) were evaluated by 5 (cardio)thoracic surgeons. Pectus excavatum was visually diagnosed in 55% to 95% of cases by different surgeons, revealing considerable inter-observer differences (kappa: 0.50; 95%-confidence interval [CI]: 0.41-0.58). All other items demonstrated inter-observer kappa's of 0.25-0.37. Intra-observer analyses evaluating the presence of pectus excavatum demonstrated a kappa of 0.81 (95%-CI: 0.72-0.91), while all other items showed intra-observer kappa's of 0.36-0.68.

CONCLUSIONS

Visual examination and diagnosis of pectus excavatum yields considerable inter-observer and intra-observer disagreements. As this variation in judgement could impact work-up and treatment strategy, objective standardization is urged.

LEVELS OF EVIDENCE

III.

Current Concepts in the Etiology and Pathogenesis of Pectus Excavatum in Humans-A Systematic Review

Pectus excavatum (PE) is the most common deformity of the chest wall and is characterized by the posterior depression of the sternum and the lower costal cartilages. To date, the etiology of PE in humans remains enigmatic. Several etiologic hypotheses have been proposed over the past two centuries. However, most of them have been scientifically dismissed and now have only historic value. In this systematic review, we assess scientific publications of the past two centuries addressing the issue of the origin of PE in humans. We present and discuss the histologic, genetic, biomechanical, and experimental scientific achievements that contributed to the clarification of its etiology and pathogenesis. With no clear consensus over the exact mechanism, most recent studies agree that the primordial defect leading the deformation of the anterior chest wall in PE is related to the costal hyaline cartilage structure and function. Further studies on this subject must be carried out. Genetic studies seem to be the most promising way to understand the exact mechanism of PE's origin and pathogenesis.

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.

Pectus cross bars increase hospital readmission rates due to serous pleural effusion

OBJECTIVE

Pectus Excavatum's (PE) surgical treatment should be patient specific. In this article, we aimed to compare parallel and cross bar variations of the Nuss method and analyze if there is any difference in results.

METHODS

In this study, a total of 891 patients treated with the Nuss method between August 2005 and February 2018 were considered. These were retrieved from a prospectively recorded PE database. Of these, 276 double-bar patients were included in the study. Patients with parallel bars (225 cases) and patients with crossed bars (51 cases) were compared in terms of age, gender, symmetry, family history, additional anomalies, mean operation time, postoperative hospital stay (days) and hospital readmission rate.

RESULTS

The mean age was measured at 20.7 for parallel bar patients and 20.1 for crossed bars patients. There was no statistically significant difference in terms of age, gender, and mean operation time between two groups. On the other hand, statistical significance was found between two groups when analyzing the deformities' symmetry, patients' family history and additional anomalies. The statistically significant difference of postoperative hospital stay between two groups is clinically negligible. Postoperative hospital readmission rates due to serous pleural effusion were found to be significantly increased in patients with crossed bars (p < 0.001).

CONCLUSION

While pleural effusion requiring readmission was statistically more frequent in cross bars, in centers where thoracentesis can be managed, Nuss method can still be applied safely, even in cases with difficult, complex deformities.

LEVEL OF EVIDENCE

III. Treatment study.

Modified Nuss procedure with a novel steel bar in patients with pectus excavatum post-congenital heart surgery

 

OBJECTIVES

Pectus excavatum (PE) can be secondary in patients who underwent sternotomy for cardiac surgery. Retrosternal adhesions increase the complexity and risk of traditional Nuss repair. Thus, we summarized the outcomes of our modified Nuss procedure using a newly designed bar.

METHODS

A retrospective analysis was performed on 35 patients who underwent modified PE repair after open heart surgery from January 2011 to July 2019. The surgery was performed using a novel bar with no need for intraoperative reshaping and rotation, assisted by thoracoscopy and subxiphoid incision when necessary.

RESULTS

There were 19 males and 16 females with a median age of 5.3 years (interquartile range, 4.1–10.9) at PE repair. All patients underwent the modified procedure uneventfully with no death. The median operating time was 70 min. Twenty-nine (82.9%) patients required subxiphoid incision assistance. There was 1 case (2.8%) with unexpected sternotomy due to intraoperative bleeding. The median length of postoperative hospital stay was 4 days. During the median 3.5 years of follow-up, no bar dislocation was found and 30 (85.7%) patients had their bars removed with no recurrence recorded. After PE repair, the Haller index improved significantly (2.6 ± 0.4 vs 4.9 ± 1.3, P < 0.05) and further decreased till the time of bar removal (2.5 ± 0.4 vs 2.6 ± 0.4, P < 0.05). All patients were satisfied with the cosmetic outcome.

CONCLUSIONS

The novel bar can be placed and removed easily with a low rate of adverse events. This modified Nuss procedure seems to be a safe, effective and convenient approach for the management of PE after cardiac surgery.

Correlation of anthropometric index and cardiopulmonary exercise testing in children with pectus excavatum

BACKGROUND

Cardiopulmonary exercise testing (CPET) is a method used to evaluate functional impairment of patients with various diseases.

OBJECTIVE

The objective was to use CPET to estimate the usability of anthropometric index (AI) in patients with pectus excavatum (PE) as a marker of functional impairment caused by chest deformity.

METHODS

The study included 32 paediatric patients (28 males) with PE. Patients underwent CPET using a breath-by-breath exhaled gas analysis method and continuous monitoring of cardiac parameters.

RESULTS

In both groups, two (overall four) patients met criteria for cardiogenic limitation (low VO₂ and low O₂Pulse). Mean VO₂/WR was below two standard deviations (2SD) in patients with less severe PE; other observed parameters were within normal limits (Z-score ± 2 SD). The AI had no observed correlation with peak ventilation, VO₂peak and peak workload.

CONCLUSION

The obtained CPET data do not correlate well with the severity of chest deformity expressed with AI. There were similar physical activity limitations in both examined groups of patients and they did not depend on the severity of the deformity.

Surface topography index: a novel deformity severity assessment index for pectus excavatum

BACKGROUND

The surface topography index (STI) has great potential in both routine computed tomography (CT) scan and emerging optical imaging systems. However, the diagnostic accuracy and stability of the STI as a deformity severity assessment index has not been fully confirmed. Therefore, the aim of the present study was to determine the diagnostic performance of the STI as a novel deformity severity assessment index for pectus excavatum.

METHODS

The present study consisted of 722 chest CT images from a single center. The standard CT index (CTI) and STI were calculated for all patients. The between-group difference and the level of compliance between the CTI and STI was analyzed by t-test and Pearson correlation. The diagnostic value and optimum discriminatory values of the CTI and STI were calculated by a receiver-operating characteristic (ROC) curve and DeLong's test.

RESULTS

The distributions of the CTI and STI were similar and showed a slight overlap between the pectus excavatum (PE) and non-PE groups. Both the CTI and STI significantly differed between the 2 groups (P<0.001). The STI demonstrated a strong Pearson correlation with the CTI (r=0.91, 95% confidence interval: 0.88-0.91, P<0.001). The ROC curves showed that STI =1.58 (sensitivity: 0.93, specificity: 0.95) could be considered equivalent to CTI =2.72 (sensitivity: 0.93, specificity: 0.97) as the optimum discriminatory values. DeLong's test showed no significant difference in the ROC curve results between the CTI and STI (Z=0.90, P=0.37).

CONCLUSIONS

The STI has comparative discrimination ability in PE diagnosis and deformity severity assessment when used with the standard CTI. The STI as a novel index is not only an ideal evaluation metric of PE deformity but also an objective trait for PE patients just as weight and height for everyone.

The Automatic Quantification of Morphological Features of Pectus Excavatum Based on Three-Dimensional Images

Visual examination and quantification of severity are essential for clinical decision making in patients with pectus excavatum. Yet, visual assessment is prone to inter- and intra-observer variability and current quantitative methods are inadequate. This study aims to develop and evaluate a novel, automatic and non-invasive method to objectively quantify pectus excavatum morphology based on three-dimensional images. Key steps of the automatic analysis are normalization of image orientation, slicing, and computation of the morphological features encompassing pectus depth, width, length, volume, position, steepness, flaring, asymmetry and mean cross-sectional area. A digital phantom mimicking a patient with pectus excavatum was used to verify the analysis method. Prospective three-dimensional imaging and subsequent surface analysis in patients with pectus excavatum was performed to assess clinical feasibility. Verification of the developed analysis tool demonstrated 100% reproducibility of all morphological feature values. Calculated parameters compared to the predetermined phantom dimensions were accurate for all but four features. The pectus width, length, volume and steepness showed an error of 4 mm (4%), 2 mm (2%), 12 mL (5%) and 1 degree (3%), respectively. Prospective imaging of 52 patients (88% males) demonstrated the feasibility of the developed tool to quantify morphological features of pectus excavatum in the clinical setting. Mean duration to calculate all features in one patient was 7.6 seconds. We have developed and presented a non-invasive pectus excavatum surface analysis tool, that is feasible to automatically quantify morphological features based on three-dimensional images with promising accuracy and reproducibility.

Transesophageal echocardiography during pectus excavatum correction in children: What happens to the heart?

OBJECTIVES

Cardiac compression in pectus excavatum remains difficult to evaluate. We describe the findings with intraoperative transesophageal echocardiography during pectus excavatum correction in pediatric patients.

METHODS

We studied right heart changes during surgical correction of pectus excavatum by transesophageal echocardiograph. Four-D echo was associated to assess morphology of the tricuspid annulus.

RESULTS

Twenty patients were included, mean age 13.5 (+/- 2.9). Mean preoperative Haller Index was 6.3 (+/- 2.63) and mean Correction Index 47.63% (+/- 12.4%). Preoperative transthoracic echocardiography at rest showed mild right heart compression in 6. Correction was gained by Nuss technique in 19, and Taulinoplasty in one. Initial transesophageal echocardiography showed compression of the right heart and deformation of the tricuspid annulus in all. During the sternal elevation, diameters of right atrium, ventricle and tricuspid annulus significantly improved: mean augmentation of right ventricle was 5.78 mm (+/- 3.56 p < 0.05), right atrium 6.64 mm (+/- 5.55 p < 0.05) and tricuspid annulus 6.02 mm (+/- 3.29 p < 0.05). The morphology of the tricuspid annulus in 4D normalized.

CONCLUSIONS

Preoperative transthoracic echocardiography at rest underestimates right chamber compression in pediatric patients with pectus excavatum. Surgical correction improves diameters of the right ventricle, right atrium and tricuspid annulus and normalizes the morphology of the tricuspid annulus (4D).

LEVEL OF EVIDENCE

Level III.

Preoperative resource utilization prior to minimally invasive repair of pectus excavatum

BACKGROUND

Preoperative testing to assess the physiologic impact of pectus excavatum is sometimes ordered to meet third-party payor preauthorization requirements. This study describes the utility of physiologic testing prior to minimally invasive repair of pectus excavatum (MIRPE).

METHODS

We retrospectively reviewed patients that underwent MIRPE from 1/2012-7/2016 at two academic children's hospitals. Data collected included demographics, insurance, Haller Index (HI), pulmonary function tests (PFTs) and echocardiograms (ECHO) obtained, and preauthorization denials.

RESULTS

A total of 360 patients (mean age 15.7 ± 2.0 years; mean HI 4.5 ± 1.5) underwent MIRPE (Hospital 1: 189, Hospital 2: 171). Commercial insurers covered 84% of patients. Hospital 1 obtained more frequent preoperative testing (PFTs: 73% vs 6%, p < 0.0001). Overall, 72% of PFTs were normal with abnormal studies limited to mild findings. Similarly, 85% of ECHOs were normal. Third-party payors more frequently denied preauthorization for MIRPE at Hospital 2 (11% vs. 5%, p = 0.03).

CONCLUSIONS

More frequent preoperative testing may decrease initial preauthorization denials for MIRPE; however, this increased utilization of resources may not be necessary as the majority of test results are normal.

The effectiveness of double-bar correction for pectus excavatum: A comparison between the parallel bar and cross-bar techniques

Purpose

To compare the effectiveness between parallel bar and cross-bar techniques for treating pectus excavatum.

Methods

A total of 80 patients who underwent parallel bar insertion (group 1) or cross-bar insertion (group 2) were evaluated retrospectively. From the pre- and post-operative chest CT images, vertebral-level-specific pectus indices were defined as the ratio of the maximum transverse diameter to the anteroposterior diameter of the thoracic cavity at a specific vertebral level and measured at 3 levels up (3Up-PI, 2Up-PI, 1Up-PI) and 1 vertebral level down (1Down-PI) from the narrowest point. The effectiveness of double-bar correction was compared between the 2 groups using postoperative vertebral level-specific pectus index changes.

Results

A total of 44 patients were enrolled in group 1, and 36 patients were enrolled in group 2. Preoperative pectus index values were not different between the 2 groups (4.5 ± 1.0 vs. 4.9 ± 1.5, P = 0.135). After double-bar correction, pectus index significantly decreased in both groups. There were no differences in postoperative pectus indices between the 2 groups (2.7 ± 0.4 vs. 2.6 ± 0.3, P = 0.197). Postoperative changes in 3Up-PI, 2Up-PI, and 1Up-PI were not significantly different between the 2 groups (P > 0.05). However, postoperative changes at the narrowest level and at 1Down-PI were significantly greater in group 2 than in group 1 (1.78 ± 0.85 vs. 2.32 ± 1.44, P = 0.009; 1.21 ± 0.70 vs. 1.70 ± 1.20, P = 0.009, respectively).

Conclusions

Double-bar correction appears to be effective for treating pectus excavatum. The cross-bar insertion technique might be superior to the parallel bar insertion technique for correcting a wider range of deformities, especially at the lower part of the depression.

Rat Animal Model of Pectus Excavatum

Background: pectus excavatum (PE) is the most common congenital deformity of the thoracic wall. Lately, significant achievements have been made in finding new, less invasive treatment methods for PE. However, most of the experimental work was carried out without the help of an animal model. In this report we describe a method to create an animal model for PE in Sprague-Dawley rats. Methods: We selected 15 Sprague-Dawley rat pups and divided them into two groups: 10 for the experimental group (EG) and 5 for the control group (CG). We surgically resected the last four pairs of costal cartilages in rats from the EG. The animals were assessed by CT-scan prior to surgery and weekly for four consecutive weeks. After four weeks, the animals were euthanized and the thoracic cage was dissected from the surrounding tissue. Results: On the first postoperative CT, seven days after surgery, we observed a marked depression of the lower sternum in all animals from the EG. This deformity was present at every CT-scan after surgery and at the post-euthanasia assessment. Conclusions: By decreasing the structural strength of the lower costal cartilages, we produced a PE animal model in Sprague-Dawley rats.

TINAG mutation as a genetic cause of pectus excavatum

To investigate the possible involvement of germline mutations in pectus excavatum (PE). We investigated a four-generation pedigree with PE. Whole-exome sequencing (WES)was performed to identify potential mutations for PE formation. Sanger sequencing was used to validate these mutations. hFOB1.19 cell proliferation was measured with a Celigo imaging cytometry system. There were four PE patients in this four-generation pedigree. In the four patients, we identified a novel heterozygous stop-gain variant in Tubulointerstitial Nephritis Antigen (TINAG) through exome sequencing: c.G2A, p.W2*. This mutation was validated by Sanger sequencing. Knockdown of TINAG inhibited the proliferation of hFOB1.19 cells. Based on these results, we hypothesize that the TINAG c.G2A mutation is a loss-of-functionmutationthat reduces TINAG expression. Increasing TINAG warrants further investigation as a potential novel anabolic mechanism of PE treatment.

Successful cardiopulmonary resuscitation following minimally invasive pectus excavatum repair: A case report

INTRODUCTION

Pectus excavatum is the most common congenital chest wall deformity. The minimally invasive repair of pectus excavatum (MIRPE) is the most commonly practiced method of surgical treatment and there is concern that the pectus bar will prevent effective CPR. There are no recorded cases of successful cardiopulmonary resuscitation with pectus bars in place.

PRESENTATION OF CASE

A 17-year-old male with pectus excavatum underwent MIRPE. Two years later, he experienced out-of-hospital cardiac arrest and underwent successful cardiopulmonary resuscitation (CPR) in the field with a pectus bar in place.

DISCUSSION

Successful CPR is possible after MIRPE. Clear identification of patients who have undergone MIRPE and education of CPR providers in providing effective chest compressions and defibrillation for this patient population is necessary.

CONCLUSION

This is the first documented case of successful CPR in a patient with a pectus bar in place who experienced out-of-hospital cardiac arrest.

The medial breast margin sign: A new sign of pectus excavatum in adult females and comparison with classic signs

INTRODUCTION

Pectus excavatum (PX) denotes a concavity of the sternum and is the most common chest wall deformity. Many characteristic signs have been described on frontal chest radiographs including increased density of the inferomedial right lung, blurring of the right heart border, steeply angled anterior ribs, horizontal posterior ribs, straight or convex left heart border and loss of silhouette of the descending thoracic aorta. These signs are often subtle and rarely all present in any individual. We describe a further sign in women with PX, the medial breast margin sign. This sign consists of more sharply defined and more vertically oriented medial breast borders on frontal chest radiographs than in those of women with normal chest wall morphology. This study aims to document the sensitivity, specificity and inter-observer reliability of the new sign, and compare with that of the previously described signs in patients with varying degrees of PX.

METHODS

The frontal chest radiographs of 185 women with PX and 50 women with normal chest wall morphology were assessed by two reviewers for the presence of the new sign and previously described signs. All the signs had their sensitivity, specificity and inter-observer reliability calculated.

RESULTS

The new sign had a sensitivity of 0.48, a specificity of 0.96 and inter-observer reliability of κ = 0.79, ranking third, second and first among all other signs, respectively.

CONCLUSION

The medial breast margin sign is useful in diagnosing PX and is comparable to the previously described classic signs.

Behavioural disorders in children with pectus excavatum in China: a retrospective cohort study with propensity score matching and risk prediction model

OBJECTIVES

Surgical repair of pectus excavatum is typically carried out immediately prior to puberty. However, at the time of surgery, some psychosocial issues, such as behavioural disorders may already have developed and the likelihood of these psychosocial disorders resolving after surgery is unclear. For this reason, some surgeons choose to perform surgical repair at an earlier age in some children. The study retrospectively compares the rate of behavioural disorders in children undergoing the Nuss procedure at 4 vs. 10 years of age. We also attempted to develop a model to predict the risk of behavioural disorders in 10 year-old patients.

METHODS

The current study included children receiving Nuss procedure for pectus excavatum at either 4 or 10 years of age. The presence/absence of behavioural disorder was assessed preoperatively, and in the third year, after removal of the bar. A propensity score matching (PSM) analysis was conducted to reduce the potential for confounding by baseline factors. Multivariable logistic regression was conducted to establish a model to predict the risk of behavioural disorders in the third year after the removal of the bar. The model was accessed by discrimination and calibration. A formula and a nomogram were developed based on the results.

RESULTS

The number of patients in each group was 45 after PSM. The rate of behavioural disorders at the baseline was significantly higher in the children undergoing Nuss procedure at 10 years of age [36% vs 20%, odds ratio (OR) 2.21, 95% confidence interval (CI) 0.85-5.72; P = 0.157]. The rate of behavioural disorders in the third year after the removal of the bar was 36% and 18% in children undergoing surgery at 10 and 4 years of age, respectively (OR 2.55, 95% CI 0.96-6.79; P = 0.094). The rate of persistent behavioural disorders, defined as continuing to have behavioural disorders in the third year after the removal of the bar in those with behavioural disorders at the baseline, was 88% vs 56% (OR 3.47, 95% CI 0.56-21.36; P = 0.204). Two patients (4%) relapsed in each group. A risk prediction model by variables of gender, Haller index, pulmonary function and score of Child Behaviour Checklist at the baseline was provided.

CONCLUSIONS

The rate of behavioural disorders was considerably lower in children who underwent the Nuss procedure at 4 years of age than at 10 years of age. Behavioural disorders may not readily resolve after surgery. Performing surgery at an early age rather than just before puberty may be better for psychosocial development. Psychosocial aid is necessary in addition to surgery to address behavioural disorders.

Comparison of magnetic resonance imaging and computed tomography to measure preoperative parameters of children with pectus excavatum

IMPORTANCE

Pectus excavatum (PE) is the most common thoracic wall deformity in children, we need a method which could be used to evaluate pulmonary functions and effects on development.

OBJECTIVE

To evaluate the use of 3D T1-weighted (3DT1) and mDIXON magnetic resonance imaging (MRI) sequences for measuring the thoracic parameters and morphology of children with PE, comparing the measurements with those made on computed tomography (CT).

METHODS

This is a retrospective study of children with thoracic deformities who were hospitalized at the Department of Thoracic Surgery of the Heart Center, Beijing Children's Hospital, between June 2014 and June 2015. Chest CT was performed first, with the MRI scanning then being performed 0-3 days later. The mDIXON sequences were obtained in inspiratory and expiratory phases and the 3DT1 sequences were obtained during free breathing. Thoracic volume was measured using the acquired images.

RESULTS

The lung volumes measured on mDIXON MRI and CT were highly correlated, with the Haller index not being significantly different between the two methods. Bland-Altman analyses showed that lung, cardiac, and retrosternal parameters were similar between the two methods. Pulmonary parameters were higher with the end-inspiratory phase mDIXON images than with the end-expiratory phase images, as expected, while cardiac parameters were unaffected by the respiratory phase.

INTERPRETATION

Thoracic volumes measured on mDIXON MRI in combination with held respiration could reflect lung volume functions and help in observing the movement functions of the lungs and heart. The method could be used instead of CT, avoiding subjecting the patient to potentially harmful radiation.

An Open, Prospective Study to Evaluate the Effectiveness and Safety of Hyaluronic Acid for Pectus Excavatum Treatment

Background

Pectus excavatum (PE) is sometimes associated with psychological and physiological difficulties influencing a patient’s quality of life. Treatment with a hyaluronic acid (HA)-based gel may benefit patients and be an alternative to other more invasive treatments.

Objectives

The authors sought to evaluate the effectiveness in terms of satisfaction, duration, and safety of HA gel treatment for PE including impact on quality of life.

Methods

Males ≥18 years having PE without functional problems received HA gel injections (50 – 150 mL) at the site of deformity and in some cases at the medial pectoralis muscle borders to optimize the aesthetic result. Follow-up visits were performed after 1, 3, 6, 12, and 24 months with optional retreatment at the 24-month visit including a 1-month follow-up. Evaluations included Pectus Excavatum Evaluation Questionnaire, patient satisfaction, magnetic resonance imaging, and safety assessments.

Results

The treatment significantly improved patients’ self-esteem (P < 0.001) and psychosocial function (P ≤ 0.038) throughout the study, as assessed by Pectus Excavatum Evaluation Questionnaire. Patients were satisfied with the aesthetic outcome and considered the treatment mild in terms of level of pain during injection. Treatment effects were maintained up to 24 months and 58% of the HA gel remained at this visit, shown by Magnetic Resonance Imaging measurements. The treatment was well tolerated.

Conclusions

Treatment of PE with HA gel improved patient quality of life related to self-esteem and psychosocial functioning including aesthetically pleasing results. The treatment may also offer benefits in terms of safety and tolerability compared with other treatments.

Level of Evidence: 4

Incremental value of three-dimensional transthoracic echocardiography over the two-dimensional modality in the assessment of right heart compression and dysfunction produced by pectus excavatum

The usefulness of two-dimensional transthoracic echocardiography (2DTTE) in the assessment of right heart compression and dysfunction produced by pectus excavatum chest wall deformity has been well described in the literature by several investigators. However, there is a paucity of reports describing incremental value of live/real time three-dimensional transthoracic echocardiography (3DTTE) over the two-dimensional technique in the evaluation of right heart function in these patients. We present a severe case of pectus excavatum chest wall deformity in a young male, in whom 3DTTE provided incremental value over standard 2DTTE in assessing compression of the right heart before surgery and marked improvement in right heart function parameters following surgical repair. In addition, an updated summary of salient features of this deformity, including 2D and 3DTTE findings as well as right heart echocardiographic parameters by both 2D and 3DTTE in normal/healthy subjects summarized from the literature have been provided in a tabular form for comparison.

Changes in thoracic cavity dimensions of pectus excavatum patients following Nuss procedure

Background

Using a simple and intuitive method, we evaluated changes in the dimensions of the thoracic cavity of pectus excavatum (PE) patients following the Nuss procedure.

Methods

We performed a retrospective review of 141 patients who had undergone the Nuss procedure. The thoracic cavity was visualized using computed tomography (CT) scans and its dimensions determined by measuring the anteroposterior (AP) and transverse (T) diameters at three anatomical landmarks (the jugular notch, and manubriosternal and xiphisternal joints). The Wilcoxon signed-rank test was used to compare differences between preoperative and postoperative parameters. Kruskal-Wallis tests were performed to compare differences among groups in patient age, type of PE, and number of inserted bars.

Results

Of the 141 patients (115 men, 26 women), 87 had symmetric and 54 had asymmetric defects. The postoperative AP diameters at the manubriosternal and xiphisternal joints were significantly higher than their preoperative values, whereas the Haller indices and T diameters at the three anatomical landmarks were significantly lower than their preoperative values. In the multiple bars group, the postoperative AP diameters increased significantly compared with their preoperative values. In the multiple bars group, and in patients aged above 13 years, the postoperative T diameters at all three anatomical landmarks decreased significantly compared with their preoperative values.

Conclusions

Correction of anterior depression of the sternum and compensatory narrowing of the chest width were observed in PE patients following the Nuss procedure. Further research will be necessary to determine the relationship between these observations and postoperative changes in chest volume.

Nuss procedure in the adult population for correction of pectus excavatum

Minimally invasive repair of pectus excavatum has been successfully modified for use in adult patients. Many patients present in adulthood with progression of symptoms as the chest wall becomes less compliant with age. A thorough workup is completed including echocardiogram and chest CT to evaluate for anatomic abnormalities. Cardiopulmonary exercise testing is done to quantify the physiologic impact. Modifications of the original Nuss procedure required to allow for successful adult repair include the use of forced sternal elevation, the use of multiple bars, medial bar fixation, and interspace support to prevent bar rotation and migration. Occasionally, fractures may occur that require an open procedure and osteotomy or cartilage resection and hybrid approach incorporating the principals of intrathoracic support and osteotomy with bar stabilization.

[Costal cartilage structural and functional changes in children with a funnel or keeled chest]

Congenital chest wall deformities (CCWDs) in children are severe diseases leading to cosmetic defects and diseases of the respiratory and cardiovascular systems. The most common of these deformities are funnel-shaped (pectus excavatum, FD) and keeled (pectus carinatum, KD) ones. The pathogenesis of CCWDs and the role of costal cartilage structural and functional changes in their pathogenesis have now been not well studied, which makes it difficult to elaborate pathogenetic approaches to correcting these diseases. Analysis of the literature has shown that structural and functional changes occur in the matrix and chondrocytes from the costal cartilage in FD. Similar costal cartilage changes are observed in KD. It is still unknown exactly which pathological processes are present in the costal cartilage and how they result in the development of one or other type of CCWDs. The role of amianthoid transformation (AT) of costal cartilages in these processes is also unknown. It is not improbable that it is AT drastically changing the native cartilage matrix, which is one of the key mechanisms leading to changes in its properties and to the subsequent development of FD or KD.