Bronchial tree of the human embryo: Examination based on a mammalian model.

The symmetry of the right and left bronchi, proposed in a previous comparative anatomical study as the basic model of the mammalian bronchial tree, was examined to determine if it applied to the embryonic human bronchial tree. Imaging data of 41 human embryo specimens at Carnegie stages (CS) 16-23 (equivalent to 6-8 weeks after fertilization) belonging to the Kyoto collection were obtained using phase-contrast X-ray computed tomography. Three-dimensional bronchial trees were then reconstructed from these images. Bronchi branching from both main bronchi were labeled as dorsal, ventral, medial, or lateral systems based on the branching position with numbering starting cranially. The length from the tracheal bifurcation to the branching point of the labeled bronchus was measured, and the right-to-left ratio of the same labeled bronchus in both lungs was calculated. In both lungs, the human embryonic bronchial tree showed symmetry with an alternating pattern of dorsal and lateral systems up to segmental bronchus B9 as the basic shape, with a more peripheral variation. This pattern is similar to that described in adult human lungs. Bronchial length increased with the CS in all labeled bronchi, whereas the right-to-left ratio was constant at approximately 1.0. The data demonstrated that the prototype of the human adult bronchial branching structure is formed and maintained in the embryonic stage. The morphology and branching position of all lobar bronchi and B6, B8, B9, and the subsegmental bronchus of B10 may be genetically determined. On the other hand, no common structures between individual embryos were found in the peripheral branches after the subsegmental bronchus of B10, suggesting that branch formation in this region is influenced more by environmental factors than by genetic factors.

Characterization of the Hyperintense Bronchus Sign as a Fetal MRI Marker of Airway Obstruction.

Background Fetal MRI-based differential diagnosis of congenital lung malformations is difficult because of the paucity of well-described imaging markers. Purpose To characterize the hyperintense bronchus sign (HBS) in in vivo fetal MRI of congenital lung malformation cases. Materials and Methods In this retrospective two-center study, fetal MRI scans obtained in fetuses with congenital lung malformations at US (January 2002 to September 2018) were reviewed for the HBS, a tubular or branching hyperintense structure within a lung lesion on T2-weighted images. The frequency of the HBS and respective gestational ages in weeks and days were analyzed. Areas under the curve (AUCs), 95% CIs, and P values of the HBS regarding airway obstruction, as found in histopathologic and postnatal CT findings as the reference standards, were calculated for different gestational ages. Results A total of 177 fetuses with congenital lung malformations (95 male fetuses) and 248 fetal MRI scans obtained at a median gestational age of 25.6 weeks (interquartile range, 8.9 weeks) were included. The HBS was found in 79% (53 of 67) of fetuses with bronchial atresia, 71% (39 of 55) with bronchopulmonary sequestration (BPS), 43% (three of seven) with hybrid lesion, 15% (six of 40) with congenital cystic adenomatoid malformation, and 13% (one of eight) with bronchogenic cyst at a median gestational age of 24.9 weeks (interquartile range, 9.7 weeks). HBS on MRI scans at any gestational age had an AUC of 0.76 (95% CI: 0.70, 0.83; P = .04) for the presence of isolated or BPS-associated airway obstruction at histopathologic analysis and postnatal CT. The AUC of HBS on fetal MRI scans obtained until gestational age of 26 weeks (AUC, 0.83; 95% CI: 0.75, 0.91; P < .001) was significantly higher (P = .045) than that for fetal MRI scans obtained after gestational age 26 weeks (AUC, 0.69; 95% CI: 0.57, 0.80; P = .004). Conclusion The hyperintense bronchus sign is a frequently detectable feature at fetal MRI and is associated with airway obstruction particularly before gestational age 26 weeks. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Dubinsky in this issue.

Bronchial tree of the human embryo: Categorization of the branching mode as monopodial and dipodial.

Some human organs are composed of bifurcated structures. Two simple branching modes-monopodial and dipodial-have been proposed. With monopodial branching, child branches extend from the sidewall of the parent branch. With dipodial branching, the tip of the bronchus bifurcates. However, the branching modes of the human bronchial tree have not been elucidated precisely. A total of 48 samples between Carnegie stage (CS) 15 and CS23 belonging to the Kyoto Collection were used to acquire imaging data with phase-contrast X-ray computed tomography. Bronchial trees of all samples were three-dimensionally reconstructed from the image data. We analyzed the lobar bronchus, segmental bronchus, and subsegmental bronchus. After calculating each bronchus length, we categorized the branching mode of the analyzed bronchi based on whether the parent bronchus was divided after generation of the analyzed bronchi. All lobar bronchi were formed with monopodial branching. Twenty-five bifurcations were analyzed to categorize the branching mode of the segmental and subsegmental bronchi; 22 bifurcations were categorized as monopodial branching, two bifurcations were not categorized as any branching pattern, and the only lingular bronchus that bifurcated from the left superior lobar bronchus was categorized as dipodial branching. The left superior lobar bronchus did not shorten during the period from CS17 or CS18, when the child branch was generated, to CS23. All analyzed bronchi that could be categorized, except for one, were categorized as monopodial branching. The branching modes of the lobar bronchus and segmental bronchus were similar in the mouse lung and human lung; however, the modes of the subsegmental bronchi were different. Furthermore, remodeling, such as shrinkage of the bronchus, was not observed during the analysis period. Our three-dimensional reconstructions allowed precise calculation of the bronchus length, thereby improving the knowledge of branching morphogenesis in the human embryonic lung.

The bronchial tree of the human embryo: an analysis of variations in the bronchial segments.

A classical study has revealed the general growth of the bronchial tree and its variations up to Carnegie stage (CS) 19. In the present study, we extended the morphological analysis CS by CS until the end of the embryonic period (CS23). A total of 48 samples between CS15 and CS23 belonging to the Kyoto Collection were used to acquire imaging data by performing phase-contrast X-ray computed tomography. Three-dimensionally reconstructed bronchial trees revealed the timeline of morphogenesis during the embryonic period. Structures of the trachea and lobar bronchus showed no individual difference during the analyzed stages. The right superior lobar bronchus was formed after the generation of both the right middle lobar bronchus and the left superior lobar bronchus. The speed of formation of the segmental bronchi, sub-segmental bronchi, and further generation seemed to vary among individual samples. The distribution of the end-branch generation among five lobes was significantly different. The median branching generation value in the right middle lobe was significantly low compared with that of the other four lobes, whereas that of the right inferior lobe was significantly larger than that of both the right and left superior lobes. Variations found between CS20 and CS23 were all described in the human adult lung, indicating that variation in the bronchial tree may well arise during the embryonic period and continue throughout life. The data provided may contribute to a better understanding of bronchial tree formation during the human embryonic period.

Differential expression of foxo genes during embryonic development and in adult tissues of Xenopus tropicalis.

The forkhead-box transcription factors of O subfamily (FOXO) play important roles in regulation of various biological functions. We cloned foxo1, foxo3, foxo4, and foxo6 from Xenopus tropicalis (hereafter X. tropicalis), and examined their expression in embryos and adult tissues. Maternal transcripts of foxo1 and foxo3 genes are detected within the animal half of the early embryo, their zygotic transcripts show distinct patterns. At late tailbud stages, foxo1 expression is observed mainly in eye, brain, branchial arches, and pronephros. In addition to eye, brain, branchial arches and pronephros, foxo3 expression is also evident in heart and somites. Foxo4 expression was not detected in oocytes. At late tailbud stages, foxo4 is mainly expressed in eye, brain, branchial arches and otic vesicle. Foxo6 expression was not detectable until stage 36, with a specific expression in nasal pits. Obvious expression of foxo1, foxo3 and foxo4, but not foxo6, is detected by RT-PCR both in oocytes and in embryos at examined stages. The expression of foxo1, foxo3 and foxo4 is observed in all tested adult tissues including heart, muscle, liver, lung, stomach and small intestine, while foxo6 is only detectable in stomach and small intestine. The differential expression pattern of foxo genes suggests that they exert distinct functions during embryonic development and in various organs of X. tropicalis.

Z scores of the fetal trachea and bronchial dimension.

OBJECTIVE: To develop Z scores for the trachea and main bronchi in normal fetuses. METHODS: This was a prospective cross-sectional study in 823 normal singleton fetuses. The tracheal diameter immediately proximal to the bifurcation and the left and right main bronchial diameters were measured from their inner to inner edge in the coronal view. Z scores were created for the trachea and main bronchial diameters using gestational age (GA), femur length (FL), and biparietal diameter (BPD) as independent variables. RESULTS: Between gestational weeks 20 and 40, the inner diameters of the trachea, left principal bronchi (LPB), and right principal bronchi (RPB) increased from 1.8 to 4.7 mm, 0.8 to 2.2 mm, and 0.9 to 2.3 mm, respectively. A simple linear regression equation was fitted to model the mean of each diameter. There was however significant heteroscedasticity of the standard deviation (SD) with increasing GA, FL, or BPD. Eventually, the following formula was used to calculate Z scores for the diameters: [measured value - equation for mean]/equation for SD. CONCLUSION: We have developed Z scores for the fetal trachea and main bronchi by applying standard statistical methods. These Z scores may be useful to evaluate the early development of the respiratory system.

Congenital tracheobronchial stenosis.

Congenital tracheobronchial stenosis is a rare disease characterized by complete tracheal rings that can affect variable lengths of the tracheobronchial tree. It causes high levels of morbidity and mortality both due to the stenosis itself and to the high incidence of other associated congenital malformations. Successful management of this complex condition requires a highly individualized approach delivered by an experienced multidisciplinary team, which is best delivered within centralized units with the necessary diverse expertise. In such settings, surgical correction by slide tracheoplasty has become increasingly successful over the past 2 decades such that long-term survival now exceeds 88%, with normalization of quality of life scores for patients with non-syndrome-associated congenital tracheal stenosis. Careful assessment and planning of treatment strategies is of paramount importance for both successful management and the provision of patients and carers with accurate and realistic treatment counseling.

Prenatal Diagnosis and Evaluation of Sonographic Predictors for Intervention and Adverse Outcome in Congenital Pulmonary Airway Malformation.

OBJECTIVE: To describe antenatal findings and evaluate prenatal risk parameters for adverse outcome or need for intervention in fetuses with congenital pulmonary airway malformation (CPAM). METHODS: In our retrospective study all fetuses with a prenatal diagnosis of CPAM detected in our tertiary referral center between 2002 and 2013 were analyzed. Sonographic findings were noted and measurements of mass-to-thorax-ratio (MTR), congenital pulmonary airway malformation volume-ratio (CVR) and observed to expected lung-to head-ratio (o/e LHR) were conducted and correlated to fetal or neonatal morbidity and mortality and/or need for prenatal intervention. RESULTS: 67 fetuses with CPAM were included in the study. Hydropic fetuses were observed in 16.4% (11/67) of cases, prenatal intervention was undertaken in 9 cases; 7 pregnancies were terminated. The survival rate of non-hydropic fetuses with conservatively managed CPAM was 98.0% (50/51), the survival rate for hydropic fetuses with intention to treat was 42.9% (3/7). 10 (18.2%) children needed respiratory assistance. Fetuses with a CVR of <0.91 were significantly less likely to experience adverse outcome or need for prenatal intervention with sensitivity, specificity and positive/negative predictive value of 0.89, 0.71, 0.62 and 0.93, respectively. A MTR (mass-to-thorax-ratio) of < 0.51 had a positive predictive value of 0.54 and a negative predictive value of 0.96 of adverse events with a sensitivity of 0.95 and a specificity of 0.63. The negative predictive value for o/e LHR of 45% was 0.84 with sensitivity, specificity and positive predictive value of 0.73, 0.68 and 0.52, respectively. CONCLUSIONS: The majority of cases with CPAM have a favorable outcome. MTR and CVR are able to identify fetuses at risk, the o/e LHR is less sensitive.

Tracheobronchial Branching Abnormalities: Lobe-based Classification Scheme.

Boyden's nomenclature, which was based on postmortem specimens and published in 1955 prior to the advent of computed tomography (CT), is commonly used to describe the normal segmental bronchial anatomy and various abnormalities. However, several additional anomalies have been recognized since that time, and there is some confusion over the names used to describe these anomalies. Several congenital branching anomalies affecting the trachea, main bronchi, and intermediate bronchus have been reported, all of which can be recognized at chest CT but are often overlooked. These anomalies, which probably occur early in fetal life, can be either supernumerary, with defects occurring at 29-30 days gestation, or displaced, with defects occurring later. Tracheobronchial positional anomalies are often associated with other congenital abnormalities but may be isolated. They often are asymptomatic but can be responsible for pulmonary symptoms such as dyspnea, recurrent pneumonia, and hemoptysis. It is essential that these anomalies are recognized prior to lung resection to avoid complications, especially when video-assisted thoracoscopic surgery is performed. In addition, bronchoscopists should be aware of these anomalies before performing diagnostic or therapeutic bronchoscopic procedures. Awareness of a few key bronchial anatomic principles and use of a lobe-based classification scheme will facilitate recognition of tracheobronchial positional anomalies.

[Role of the Sonic Hedgehog pathway in thoracic cancers]. / Rôle de la voie Sonic Hedgehog dans les cancers thoraciques.

INTRODUCTION: Sonic Hedgehog (Shh) pathway is physiologically activated during embryogenesis and development. It plays a role in idiopathic lung fibrosis and is also activated in several solid cancers. STATE OF THE ART: Shh pathway is reactivated in thoracic cancers, as small cell lung carcinoma, non-small cell lung carcinoma and malignant pleural mesothelioma. Shh pathway is associated with cancer stem cells and seems to have a crucial role in tumor proliferation, aggressiveness and chemoresistance in these cancers. This review describes the activation mode of Shh pathway in thoracic cancers and its role in small cell lung carcinoma, non-small cell lung carcinoma and malignant pleural mesothelioma, using in vitro and in vivo models. Notably, data from literature show that inhibition of Shh pathway has an antitumor action and sensitizes to chemotherapy. PERSPECTIVES: These results incite to develop targeted therapies against Shh pathway in the treatment of thoracic cancers.

Two nested developmental waves demarcate a compartment boundary in the mouse lung.

The lung is a branched tubular network with two distinct compartments--the proximal conducting airways and the peripheral gas exchange region--separated by a discrete boundary termed the bronchoalveolar duct junction (BADJ). Here we image the developing mouse lung in three-dimensions (3D) and show that two nested developmental waves demarcate the BADJ under the control of a global hormonal signal. A first wave of branching morphogenesis progresses throughout embryonic development, generating branches for both compartments. A second wave of conducting airway differentiation follows the first wave but terminates earlier, specifying the proximal compartment and setting the BADJ. The second wave is terminated by a glucocorticoid signalling: premature activation or loss of glucocorticoid signalling causes a proximal or distal shift, respectively, in BADJ location. The results demonstrate a new mechanism of boundary formation in complex, 3D organs and provide new insights into glucocorticoid therapies for lung defects in premature birth.

Novel patterns for the growing main bronchi in the human fetus: an anatomical, digital and statistical study.

PURPOSE: Intensive progress in prenatal medicine results in performing airway management in the fetus affected by life-threatening congenital malformations. This study aimed to examine age-specific reference intervals and growth dynamics for length, proximal and distal external transverse diameters, and projection surface areas of the two main bronchi at varying gestational ages, including their relative growth in length and projection surface area. MATERIALS AND METHODS: Using anatomical dissection, digital image analysis and statistics, length, proximal and distal external transverse diameters, and projection surface areas of the right and left main bronchi were examined in 73 human fetuses (39 males, 34 females) aged 14-25 weeks, derived from spontaneous abortions and stillbirths. RESULTS: Statistical analysis showed no sex differences. Between the 14 and 25th week of gestation, the lengths of the right and left main bronchi increased from 1.43 ± 0.18 to 3.18 ± 0.39 mm, and from 2.97 ± 0.16 to 7.58 ± 1.95 mm, in accordance with the functions: [Formula: see text], respectively. The proximal external transverse diameters of the right and left main bronchi varied from 2.13 ± 0.41 to 4.24 ± 0.20 mm, and from 1.84 ± 0.06 to 3.67 ± 0.66 mm, following the logarithmic models: [Formula: see text], respectively. The distal external transverse diameter rose from 2.09 ± 0.47 to 4.24 ± 0.20 mm, as [Formula: see text] for the right main bronchus, and from 1.85 ± 0.04 to 3.67 ± 0.66 mm, like [Formula: see text] for the left one. On either side, there were no statistically significant differences between values of the proximal and distal transverse diameters of the main bronchus. The projection surface areas of the right and left main bronchi ranged from 2.95 ± 0.19 to 13.34 ± 2.12 mm(2), and from 5.57 ± 0.21 to 28.52 ± 5.24 mm(2), as [Formula: see text] and [Formula: see text]. The two main bronchi revealed a proportionate increase in both length and projection surface area, since the right-to-left bronchial length ratio and the right-to-left bronchial projection surface area ratio were stable, 0.41 ± 0.07 and 0.47 ± 0.08, respectively, throughout the analyzed period. CONCLUSIONS: The main bronchi show no sex differences. The right and left main bronchi grow logarithmically in length and external transverse diameter, and linearly in projection surface area. The right and left main bronchi evolve proportionately, with the right-to-left bronchial ratios of 0.41 ± 0.07 for length, and 0.47 ± 0.08 for projection surface area.

Establishment of smooth muscle and cartilage juxtaposition in the developing mouse upper airways.

In the trachea and bronchi of the mouse, airway smooth muscle (SM) and cartilage are localized to complementary domains surrounding the airway epithelium. Proper juxtaposition of these tissues ensures a balance of elasticity and rigidity that is critical for effective air passage. It is unknown how this tissue complementation is established during development. Here we dissect the developmental relationship between these tissues by genetically disrupting SM formation (through Srf inactivation) or cartilage formation (through Sox9 inactivation) and assessing the impact on the remaining lineage. We found that, in the trachea and main bronchi, loss of SM or cartilage resulted in an increase in cell number of the remaining lineage, namely the cartilage or SM, respectively. However, only in the main bronchi, but not in the trachea, did the loss of SM or cartilage lead to a circumferential expansion of the remaining cartilage or SM domain, respectively. In addition to SM defects, cartilage-deficient tracheas displayed epithelial phenotypes, including decreased basal cell number, precocious club cell differentiation, and increased secretoglobin expression. These findings together delineate the mechanisms through which a cell-autonomous disruption of one structural tissue can have widespread consequences on upper airway function.

Apical constriction initiates new bud formation during monopodial branching of the embryonic chicken lung.

Branching morphogenesis sculpts the airway epithelium of the lung into a tree-like structure to conduct air and promote gas exchange after birth. In the avian lung, a series of buds emerges from the dorsal surface of the primary bronchus via monopodial branching to form the conducting airways; anatomically, these buds are similar to those formed by domain branching in the mammalian lung. Here, we show that monopodial branching is initiated by apical constriction of the airway epithelium, and not by differential cell proliferation, using computational modeling and quantitative imaging of embryonic chicken lung explants. Both filamentous actin and phosphorylated myosin light chain were enriched at the apical surface of the airway epithelium during monopodial branching. Consistently, inhibiting actomyosin contractility prevented apical constriction and blocked branch initiation. Although cell proliferation was enhanced along the dorsal and ventral aspects of the primary bronchus, especially before branch formation, inhibiting proliferation had no effect on the initiation of branches. To test whether the physical forces from apical constriction alone are sufficient to drive the formation of new buds, we constructed a nonlinear, three-dimensional finite element model of the airway epithelium and used it to simulate apical constriction and proliferation in the primary bronchus. Our results suggest that, consistent with the experimental results, apical constriction is sufficient to drive the early stages of monopodial branching whereas cell proliferation is dispensable. We propose that initial folding of the airway epithelium is driven primarily by apical constriction during monopodial branching of the avian lung.

A role for mesenchyme dynamics in mouse lung branching morphogenesis.

Mammalian airways are highly ramified tree-like structures that develop by the repetitive branching of the lung epithelium into the surrounding mesenchyme through reciprocal interactions. Based on a morphometric analysis of the epithelial tree, it has been recently proposed that the complete branching scheme is specified early in each lineage by a programme using elementary patterning routines at specific sites and times in the developing lung. However, the coupled dynamics of both the epithelium and mesenchyme have been overlooked in this process. Using a qualitative and quantitative in vivo morphometric analysis of the E11.25 to E13.5 mouse whole right cranial lobe structure, we show that beyond the first generations, the branching stereotypy relaxes and both spatial and temporal variations are common. The branching pattern and branching rate are sensitive to the dynamic changes of the mesoderm shape that is in turn mainly dependent upon the volume and shape of the surrounding intrathoracic organs. Spatial and temporal variations of the tree architecture are related to local and subtle modifications of the mesoderm growth. Remarkably, buds never meet after suffering branching variations and continue to homogenously fill the opening spaces in the mesenchyme. Moreover despite inter-specimen variations, the growth of the epithelial tree and the mesenchyme remains highly correlated over time at the whole lobe level, implying a long-range regulation of the lung lobe morphogenesis. Together, these findings indicate that the lung epithelial tree is likely to adapt in real time to fill the available space in the mesenchyme, rather than being rigidly specified and predefined by a global programme. Our results strongly support the idea that a comprehensive understanding of lung branching mechanisms cannot be inferred from the branching pattern or behavior alone. Rather it needs to be elaborated upon with the reconsideration of mesenchyme-epithelium coupled growth and lung tissues mechanics.

[Tracheobronchial and pulmonary parenchymatous congenital abnormalities requiring surgical treatment in adults]. / Malformations trachéobronchiques et parenchymateuses pulmonaires de l'adulte relevant d'un traitement chirurgical.

Most tracheobronchial and parenchymatous congenital abnormalities of the respiratory system are diagnosed in early life. However, some lesions may be initially silent and diagnosed only in adulthood. These cases included congenital abnormalies of the tracheobronchial tract (tracheal and/or bronchial stenosis, bronchogenic cysts, bronchial atresia, oesotracheal fistula, oesobronchial fistula, and tracheal diverticulum), and lung parenchyma itself (pulmonary sequestration, congenital cystic adenomatoïd malformation, lobar emphysema, lobar or lung hypoplasia). To avoid dreadful complications, these rare cases deserve surgical management, and must be known by chest physicians and surgeons.

mSmile is necessary for bronchial smooth muscle and alveolar myofibroblast development.

Disrupted lung alveolar myofibroblast and bronchial smooth muscle (BSM) cell development may lead to pulmonary disorders such as bronchopulmonary dysplasia. The molecular mechanisms that regulate BSM and alveolar myofibroblast development are not fully understood. Here we show that mSmile (murine Smile), a novel transmembrane protein with tetratricopeptide repeats, functions in lung alveolar myofibroblast and BSM cell development. mSmile mutant mice exhibit early neonatal lethality with few mice surviving up to 3 weeks. Mutant lungs display both airway branching morphogenesis defect during fetal lung development and alveolarization defect after birth. These defects are associated with reduced numbers of BSM cells in the peribronchial subepithelial region and clefts and myofibroblasts in alveolar septae. Expression of fibroblast growth factor-10 and its down stream target Bmp-4, which are important for BSM formation, is decreased. In vitro, mSmile mutant embryonic fibroblasts show reduced receptor activation and induction of myofibroblast formation in response to Transforming growth factor-ß (Tgf-ß), indicating that mSmile may mediate myofibroblast development through modulation of Tgf-ß signaling. These studies identify mSmile as a novel gene specifying both the BSM and lung alveolar myofibroblast lineages, contributing to our understanding of the biological control of the development of these cells, and may provide insights into the aberrant smooth muscle and alveolar myofibroblast development that occur in pathological conditions.

Pre-hatch lung development in the ostrich.

We studied development of the ostrich lung using light microscopy as well as electron microscopy techniques. At E24, the lung comprised a few epithelial tubes, interspersed with abundant mesenchyme with scattered profiles of incipient blood vessels. Between E24 and E39, the epithelial thickness was reduced by 90% from 13.5 ± 0.41 µm to 1.33 ± 0.014 µm (mean ± SD, respectively). Atria were evident at E32, and by E35, the first portions of the blood-gas barrier (BGB) measuring 3.41 ± 1.12 µm were encountered. Gas exchange tissue was well formed by E39 with atria, infundibulae, air capillaries and a mature blood-gas barrier (BGB). BGB formation proceeded through the complex processes of secarecytosis and peremerecytosis, which entailed decapitation of epithelial cells by cutting or pinching off respectively and by E39, the BGB was thin at 2.21 ± 1.21 µm. Vascular remodeling by intussusceptive angiogenesis was a late stage process mediated by intraluminal pillars in the pulmonary vasculature.

[Relationship between congenital heart disease and bronchial dysplasia].

OBJECTIVE: To study the relationship of the incidence of bronchial dysplasia (bronchial anomalous origin and bronchial stenosis) with congenital heart disease. METHODS: A total of 185 children with congenital heart disease or bronchial dysplasia were enrolled. Bronchial dysplasia was identified by the 64-MSCT conventional scanning or thin slice scanning with three-dimensional reconstruction. RESULTS: Forty-five children (25.3%) had coexisting bronchial dysplasia and congenital heart disease. The incidence rate of bronchial dysplasia in children with congenital heart disease associated with ventricular septal defect was higher than in those without ventricular septal defect (33.7% vs 15.0%; P<0.05). There were no significant differences in the incidence rate of bronchial dysplasia between the children with congenital heart disease who had a large vascular malformation and who did not. CONCLUSIONS: Bronchial dysplasia often occurs in children with congenital heart disease. It is necessary to perform a tracheobronchial CT scanning with three-dimensional reconstruction to identify tracheobronchial dysplasia in children with congenital heart disease, especially associated with ventricular septal defect.

Bronchomegaly as a complication of fetal endoscopic tracheal occlusion. A caution and a possible solution.

Fetal medicine is developing rapidly and aims to improve the outcome for fetuses with congenital anomalies. Fetal endoscopic tracheal occlusion (FETO) has been developed for fetuses with congenital diaphragmatic hernia to counterbalance the compression of the lung by the abdominal viscera, preserving the pulmonary maturation. Because the perinatal morbidity and mortality of patients treated with FETO have decreased, new complications are emerging in the older survivors. Tracheomegaly has been reported to be a late complication of FETO, sometimes requiring tracheostomy. We report a case of bronchial dilatation after FETO and suggest an alternative surgical treatment.