Structural airway anomalies in patients with DiGeorge syndrome: a current review

Thermoablative Techniques to Treat Excessive Central Airway Collapse

Excessive central airway collapse (ECAC) is a condition characterized by the excessive narrowing of the trachea and mainstem bronchi during expiration, which can be caused by Tracheobronchomalacia (TBM) or Excessive Dynamic Airway Collapse (EDAC). The initial standard of care for central airway collapse is to address any underlying conditions such as asthma, COPD, and gastro-esophageal reflux. In severe cases, when medical treatment fails, a stent-trial is offered to determine if surgical correction is a viable option, and tracheobronchoplasty is suggested as a definitive treatment approach. Thermoablative bronchoscopic treatments, such as Argon plasma coagulation (APC) and laser techniques (potassium-titanyl-phosphate [KTP], holmium and yttrium aluminum pevroskyte [YAP]) are a promising alternative to traditional surgery. However, further research is needed to assess their safety and effectiveness in humans before being widely used.

Chromosome 22q11.2 Deletion Syndrome: A Comprehensive Review of Molecular Genetics in the Context of Multidisciplinary Clinical Approach

The 22q11.2 deletion syndrome is a multisystemic disorder characterized by a marked variability of phenotypic features, making the diagnosis challenging for clinicians. The wide spectrum of clinical manifestations includes congenital heart defects-most frequently conotruncal cardiac anomalies-thymic hypoplasia and predominating cellular immune deficiency, laryngeal developmental defects, midline anomalies with cleft palate and velar insufficiency, structural airway defects, facial dysmorphism, parathyroid and thyroid gland hormonal dysfunctions, speech delay, developmental delay, and neurocognitive and psychiatric disorders. Significant progress has been made in understanding the complex molecular genetic etiology of 22q11.2 deletion syndrome underpinning the heterogeneity of clinical manifestations. The deletion is caused by chromosomal rearrangements in meiosis and is mediated by non-allelic homologous recombination events between low copy repeats or segmental duplications in the 22q11.2 region. A range of genetic modifiers and environmental factors, as well as the impact of hemizygosity on the remaining allele, contribute to the intricate genotype-phenotype relationships. This comprehensive review has been aimed at highlighting the molecular genetic background of 22q11.2 deletion syndrome in correlation with a clinical multidisciplinary approach.

Suckling, Feeding, and Swallowing: Behaviors, Circuits, and Targets for Neurodevelopmental Pathology

All mammals must suckle and swallow at birth, and subsequently chew and swallow solid foods, for optimal growth and health. These initially innate behaviors depend critically upon coordinated development of the mouth, tongue, pharynx, and larynx as well as the cranial nerves that control these structures. Disrupted suckling, feeding, and swallowing from birth onward-perinatal dysphagia-is often associated with several neurodevelopmental disorders that subsequently alter complex behaviors. Apparently, a broad range of neurodevelopmental pathologic mechanisms also target oropharyngeal and cranial nerve differentiation. These aberrant mechanisms, including altered patterning, progenitor specification, and neurite growth, prefigure dysphagia and may then compromise circuits for additional behavioral capacities. Thus, perinatal dysphagia may be an early indicator of disrupted genetic and developmental programs that compromise neural circuits and yield a broad range of behavioral deficits in neurodevelopmental disorders.

Assessment of airway abnormalities in patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals

BACKGROUND

Children with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals (TOF/MAPCAs) are at risk for post-operative respiratory complications after undergoing unifocalisation surgery. Thus, we assessed and further defined the incidence of airway abnormalities in our series of over 500 children with TOF/MAPCAs as determined by direct laryngoscopy, chest computed tomography (CT), and/or bronchoscopy.

METHODS

The medical records of all patients with TOF/MAPCAs who underwent unifocalisation or pulmonary artery reconstruction surgery from March, 2002 to June, 2018 were reviewed. Anaesthesia records, peri-operative bronchoscopy, and/or chest CT reports were reviewed to assess for diagnoses of abnormal or difficult airway. Associations between chromosomal anomalies and airway abnormalities - difficult anaesthetic airway, bronchoscopy, and/or CT findings - were defined.

RESULTS

Of the 564 patients with TOF/MAPCAs who underwent unifocalisation or pulmonary artery reconstruction surgery at our institution, 211 (37%) had a documented chromosome 22q11 microdeletion and 28 (5%) had a difficult airway/intubation reported at the time of surgery. Chest CT and/or peri-operative bronchoscopy were performed in 234 (41%) of these patients. Abnormalities related to malacia or compression were common. In total 35 patients had both CT and bronchoscopy within 3 months of each other, with concordant findings in 32 (91%) and partially concordant findings in the other 3.

CONCLUSION

This is the largest series of detailed airway findings (direct laryngoscopy, CT, and bronchoscopy) in TOF/MAPCAS patients. Although these findings are specific to an at-risk population for airway abnormalities, they support the utility of CT and /or bronchoscopy in detecting airway abnormalities in patients with TOF/MAPCAs.

Clinical and immunological features in a cohort of patients with partial DiGeorge syndrome followed at a single center

DiGeorge syndrome (DGS) is a primary immunodeficiency characterized by various degrees of T-cell deficiency. In partial DGS (pDGS), other risk factors could predispose to recurrent infections, autoimmunity, and allergy. The aim of this study was to assess the effect of different factors in the development of infections, autoimmunity, and/or allergy in patients with pDGS. We studied 467 pDGS patients in follow-up at Great Ormond Street Hospital. Using a multivariate approach, we observed that palatal anomalies represent a risk factor for the development of recurrent otitis media with effusion. Gastroesophageal reflux/dysphagia and asthma/rhinitis represent a risk factor for the development of recurrent upper respiratory tract infections. Allergy and autoimmunity were associated with persistently low immunoglobulin M levels and lymphopenia, respectively. Patients with autoimmunity showed lower levels of CD3⁺, CD3⁺CD4⁺, and naïve CD4⁺CD45RA⁺CD27⁺ T lymphocytes compared with pDGS patients without autoimmunity. We also observed that the physiological age-related decline of the T-cell number was slower in pDGS patients compared with age-matched controls. The age-related recovery of the T-cell number depended on a homeostatic peripheral proliferation of T cells, as suggested by an accelerated decline of the naïve T lymphocytes in pDGS as well as a more skewed T-cell repertoire in older pDGS patients. These evidences suggest that premature CD4⁺ T-cell aging and lymphopenia induced spontaneous peripheral T-cell proliferation might contribute to the pathogenesis of autoimmunity in patients with pDGS. Infections in these patients represent, in most of the cases, a complication of anatomical or gastroenterological anomalies rather than a feature of the underlying immunodeficiency.

Deletion of 22q11 chromosome is associated with postoperative morbidity after unifocalisation surgery

BACKGROUND

A 22q11 chromosome deletion is common in patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals. We sought to determine whether 22q11 chromosome deletion is associated with increased postoperative morbidity after unifocalisation surgery.

METHODS

We included all patients with this diagnosis undergoing primary or revision unifocalisation ± ventricular septal defect closure at our institution from 2008 to 2016, and we excluded patients with unknown 22q11 status. Demographic and surgical data were collected. We compared outcomes between those with 22q11 chromosome deletion and those without using non-parametric analysis.

RESULTS

We included 180 patients, 41% of whom were documented to have a chromosome 22q11 deletion. Complete unifocalisation was performed in all patients, and intracardiac repair was performed with similar frequency regardless of 22q11 chromosome status. Duration of mechanical ventilation was longer in 22q11 deletion patients. This difference remained significant after adjustment for delayed sternal closure and/or intracardiac repair. Duration of ICU stay was longer in patients with 22q11 deletion, although no longer significant when adjusted for delayed sternal closure and intracardiac repair. Finally, length of hospital stay was longer in 22q11-deleted patients, but this difference was not significant on unadjusted or adjusted analysis.

CONCLUSION

Children with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals and 22q11 deletion are at risk for greater prolonged mechanical ventilation after unifocalisation surgery. Careful attention should be given to the co-morbidities of this population in the perioperative period to mitigate risks that may complicate the postoperative course.

Airway Anomalies in Patients With 22q11.2 Deletion Syndrome: A 5-Year Review

OBJECTIVES

To characterize the frequency of airway anomalies in patients with 22q11.2 deletion syndrome (22q11DS).

METHODS

Retrospective review of patients with 22q11DS who had undergone microlaryngoscopy/bronchoscopy (MLB) for aerodigestive symptoms at a tertiary care children's hospital from 2011 to 2016.

RESULTS

Thirty patients underwent an MLB due to the following indications: aspiration (11), stridor (10), chronic respiratory failure due to ventilator dependence (8), and difficult intubation (1). Median age at MLB was 6.5 months (range, 0.25-32 months). Forty airway anomalies were identified in 20 (66%) patients. Laryngomalacia (10), tracheomalacia (8), and bronchomalcia (8) were the most common intraoperative findings, followed by laryngeal cleft (5), anterior glottic web (5), subglottic stenosis (3), and subglottic cysts (1). Synchronous airway anomalies were common and identified in 11 (55%) of the patients who had identified anomalies on MLB. Nineteen of the 20 patients required operative intervention due to the anomalies identified.

CONCLUSIONS

Structural airway abnormalities are common in children with 22q11DS undergoing MLB, and synchronous anomalies can frequently exist. Providers caring for children with 22q11DS should be vigilant about airway evaluation when aerodigestive symptoms are present.

The comorbidities and risk factors in children with congenital airway anomalies: A nationwide population-based study in Taiwan

The comorbidities and risk factors associated with congenital airway anomalies (CAAs) in children are undecided. This study aimed to investigate the comorbidities commonly associated with CAA and to explore the prognosis and risk factors in CAA children.This nationwide, population-based cohort study was conducted between 2000 and 2011 with children aged 0 to 5 years assigned to either a CAA group (6341 patients) that diagnosed with CAA or an age- and gender-matched control group (25,159 patients) without CAA, using the Taiwan National Health Insurance Research Database (NHIRD). Descriptive, logistic regression, Kaplan-Meier, and Cox regression analyses were used for the investigation.Cleft lip/palate (adjusted odds ratio [aOR], 7.88; 95% confidence interval [CI], 6.49-9.59), chromosome (aOR, 6.85; 95% CI, 5.03-9.34), and congenital neurologic (aOR, 5.52; 95% CI, 4.45-6.87) anomalies were the comorbidities most highly associated with CAA. Of the 31,500 eligible study patients, 636 (399 in the CAA group and 237 in the control group) died during the follow-up period (6.3% vs 0.9%, P < .001). The mortality risk after adjusting for age, gender, and comorbidities elevated significantly among CAA patients (adjusted hazard ratio [aHR], 4.59; 95% CI, 3.85-5.48). The need for tracheostomy (aHR, 2.98; 95% CI, 2.15-4.15), comorbidity with congenital heart disease (CHD) (aHR, 2.52; 95% CI, 2.05-3.10), and chromosome anomaly (aHR, 2.34; 95% CI, 1.70-3.23) were the independent risk factors most greatly related to CAA mortality.This study demonstrated that CAA was most highly associated with the comorbidities as cleft lip/palate, chromosome, and congenital neurologic anomalies. The CAA children had a significantly elevated mortality risk; the need for tracheostomy, CHD, and chromosome anomaly were the most related risk factors of mortality for CAA. Further studies are warranted to clarify the involved mechanisms.

Association Between Tetralogy of Fallot and Tracheobronchial Branching Abnormalities: A New Clue for Pathogenesis?

Background

In our practice, we noticed an increased frequency of tracheobronchial branching abnormalities (TBAs) in patients with tetralogy of Fallot (ToF). This study aimed to determine whether an association exists between congenital TBAs and ToF with or without pulmonary atresia.

Methods and Results

The frequency of TBAs on chest computed tomography was assessed in 55 patients with ToF without pulmonary atresia, 34 patients with ToF with pulmonary arteria, and 100 control patients. We then looked for a possible association between TBAs and pulmonary artery branch hypoplasia, the presence of major aortopulmonary collateral arteries, and the presence of the chromosome 22q11 deletion. TBAs were significantly more frequent in patients with ToF with or without pulmonary atresia than in the control group (any TBAs, 21% versus 2% [P<0.001]; bronchial situs anomalies, 6% versus 0% [P=0.002]; right tracheal bronchus, 4% versus 0% [P=0.04]; left eparterial bronchus, 8% versus 0% [P=0.005]); and tended to be more frequent in those with ToF without pulmonary atresia than in those with ToF with pulmonary atresia (any TBAs, 27% versus 12% [P=0.11]; left eparterial bronchus, 13% versus 0% [P=0.04]). TBAs were readily multiple (8 patients of 19 with TBA) and concerned essentially the upper lobes. TBAs were not associated with pulmonary branch hypoplasia, major aortopulmonary collateral arteries, or the chromosome 22q11 deletion.

Conclusions

We demonstrated a significantly increased frequency of tracheobronchial abnormalities in patients with ToF with or without pulmonary atresia compared with a control group. These results suggest an interaction between abnormalities in conotruncal septation and tracheobronchial branching and may provide a new clue to the pathogenesis of conotruncal heart diseases.

Bronchoscopy in children with tetralogy of fallot, pulmonary atresia, and major aortopulmonary collaterals

OBJECTIVE

Children with Tetralogy of Fallot, Pulmonary Atresia, and Major Aortopulmonary Collaterals (TOF/PA/MAPCAs) undergoing unifocalization surgery are at risk for developing more postoperative respiratory complications than children undergoing other types of congenital heart surgery. Bronchoscopy is used in the perioperative period for diagnostic and therapeutic purposes. In this study, we describe bronchoscopic findings and identify factors associated with selection for bronchoscopy.

DESIGN

Retrospective case-control.

PATIENTS AND METHODS

All patients with TOF/PA/MAPCAs who underwent unifocalization surgery from September 2005 through March 2016 were included. Patients who underwent bronchoscopy in the perioperative period were compared to a randomly selected cohort of 172 control patients who underwent unifocalization without bronchoscopy during the study period.

RESULTS

Forty-three children underwent perioperative bronchoscopy at a median of 9 days postoperatively. Baseline demographics were similar in bronchoscopy patients and controls. Patients who underwent bronchoscopy were more likely to have a chromosome 22q11 deletion and were more likely have undergone unifocalization surgery without intracardiac repair. These patients had a longer duration of mechanical ventilation, ICU duration, and length of hospitalization. Abnormalities were detected on bronchoscopy in 35 patients (81%), and 20 (35%) of bronchoscopy patients underwent a postoperative intervention related to abnormalities identified on bronchoscopy.

CONCLUSION

Bronchoscopy is a useful therapeutic and diagnostic instrument for children undergoing unifocalization surgery, capable of identifying abnormalities leading to an additional intervention in over one third of patients. Special attention should be given to children with a 22q11 deletion to expedite diagnosis and intervention for possible airway complications.

Congenital nasal obstruction in infants: A retrospective study and literature review

OBJECTIVES

To identify etiologies of congenital nasal obstruction and describe clinical practice patterns in the evaluation, diagnosis, and treatment of symptomatic infants.

METHODS

An electronic chart review from 1/1/2006-10/1/2016 for all patients with a diagnosis of nasal obstruction within the first six months of life using ICD-9 and 10 codes 478.19 and J34.89.

RESULTS

A total of 34 patients were evaluated by the Division of Otolaryngology for this chief complaint. 38% of neonates were born premature and 32% were admitted to the NICU at birth, with a female-to-male ratio of 1:1.4. Presenting signs and symptoms included: stertor (44%), cyanosis (24%), stridor (24%), retractions (21%), rhinorrhea (21%), apnea (12%), and epistaxis (8%). 47% of patients received ancillary radiographic imaging (CT or MRI). Diagnoses observed include: midnasal stenosis (38%), pyriform aperture stenosis (21%), choanal stenosis (12%), dacryocystocele (6%), microrhinia (6%), septal deviation (6%), nasopharyngeal reflux (3%), nasopharyngeal teratoma (3%), neonatal rhinitis (3%), and pharyngeal wall collapse (3%). 71% of patients were noted to have bilateral nasal obstruction. 41% of infants were found to have an associated ear, nose, and throat anomaly. 15% of patients required surgical intervention. The mean time-to-resolution was 240 days.

CONCLUSION

Congenital nasal obstruction has a broad differential diagnosis: the timing, onset, and laterality of symptoms can provide insights into the source of upper airway compromise. Most infants improve through conservative management (i.e. suctioning, humidification) and medical therapies (i.e. intranasal drops, nasal sprays).

Association of airway abnormalities with 22q11.2 deletion syndrome

INTRODUCTION

22q11.2 deletion syndrome (22q11.2DS) presents with complex but variable symptoms, including cardiac, immune, palatal, endocrine, cognitive, and psychiatric issues. However, an association of 22q11.2DS with structural airway abnormalities has not been formally described. The aim of this study was to document the frequency of this association.

METHODS

We retrospectively reviewed medical records of patients with 22q11.2DS evaluated in the 22q and You Center at the Children's Hospital of Philadelphia between 1999 and 2015 referred to otolaryngology for an airway assessment. Type of airway abnormality and presence of comorbidities, such as congenital heart disease, tracheostomy, and association with prenatal symptomatology such as polyhydramnios, were noted.

RESULTS

Of the 104 patients who underwent an otolaryngology procedure (microlaryngoscopy or bronchoscopy), 71% (n = 74) had airway abnormalities. Patients with airway abnormalities ranged in age from 5 months to 37 years, with similar prevalence among males and females. Observed airway abnormalities included tracheomalacia (36%), subglottic stenosis (28%), laryngomalacia (26%), glottic web (21%), and bronchomalacia (16%). Most patients with airway abnormalities (91%) had an associated congenital heart defect, with ventricular septal defect and Tetralogy of Fallot being the most prevalent. Importantly, 30% of patients required a tracheostomy, and overall polyhydramnios was noted in 16% of pregnancies.

CONCLUSION

Airway abnormalities are a common feature of 22q11.2DS, leading to substantial morbidity, particularly when combined with complex cardiac disease. Polyhydramnios may be an important prenatal clue to both the diagnosis of 22q11.2DS and airway anomalies. Postnatal assessment of airway structure and function among patients with 22q11.2DS is an important component of overall evaluation and will help guide long-term management.

Pharyngeal Wall Collapse and Multiple Synchronous Airway Lesions

Pharyngeal wall inspiratory collapse (PWIC) is a dynamic obstruction of the air column proximal to the glottis during inspiration. Our objectives were to assess PWIC's incidence and its contribution to the symptoms of upper airway obstruction (UAO), and to propose indications for intervention. In a retrospective review of consecutive endoscopic evaluations and clinical data of 108 infants with UAO, PWIC was diagnosed in 50 infants (46%). The most common presenting symptom was apnea (52%). The PWIC was accompanied by 2 to 7 synchronous airway abnormalities, most frequently laryngomalacia (78%). Generalized hypotonia was the most common associated systemic finding (80%). Severe PWIC cases required bi-level positive airway pressure (BiPAP). The severity of PWIC, measured by a newly developed classification, was positively correlated to apnea (p < .05) and the need for BiPAP (p < .054). Spontaneous recovery occurred within 36 months. The incidence of PWIC among infants with UAO is high, and its role in UAO deserves greater recognition. Better diagnosis of PWIC will improve the treatment of UAO.

Airway Compression by Major Aortopulmonary Collaterals with 22q11 Deletion

Hypoxic choking episodes due to airway obstruction occurred frequently from 4 months of age in a boy with 22q11 deletion, pulmonary atresia, ventricular septal defect, absent central pulmonary artery, tracheobronchomalacia, and an aberrant right tracheal bronchus. The tracheobronchial tree was compressed by a posteriorly displaced ascending aorta and right aortic arch with aberrant left subclavian artery and major aortopulmonary collateral arteries. Single-stage unifocalization and intracardiac repair plus aortopexy at 8 months resulted in resolution of the respiratory distress and heart failure.

Risk Factors for Extubation Failure Following Neonatal Cardiac Surgery

OBJECTIVE

Extubation failure after neonatal cardiac surgery has been associated with considerable postoperative morbidity, although data identifying risk factors for its occurrence are sparse. We aimed to determine risk factors for extubation failure in our neonatal cardiac surgical population.

DESIGN

Retrospective chart review.

SETTING

Urban tertiary care free-standing children's hospital.

PATIENTS

Neonates (0-30 d) who underwent cardiac surgery at our institution between January 2009 and December 2012 was performed.

INTERVENTIONS

Extubation failure was defined as reintubation within 72 hours after extubation from mechanical ventilation. Multivariate logistic regression analysis was performed to determine independent risk factors for extubation failure.

MEASUREMENTS AND MAIN RESULTS

We included 120 neonates, of whom 21 (17.5%) experienced extubation failure. On univariate analysis, patients who failed extubation were more likely to have genetic abnormalities (24% vs 6%; p = 0.023), hypoplastic left heart (43% vs 17%; p = 0.009), delayed sternal closure (38% vs 12%; p = 0.004), postoperative infection prior to extubation (38% vs 11%; p = 0.002), and longer duration of mechanical ventilation (median, 142 vs 58 hr; p = 0.009]. On multivariate analysis, genetic abnormalities, hypoplastic left heart, and postoperative infection remained independently associated with extubation failure. Furthermore, patients with infection who failed extubation tended to receive fewer days of antibiotics prior to their first extubation attempt when compared with patients with infection who did not fail extubation (4.9 ± 2.6 vs 7.3 ± 3; p = 0.073).

CONCLUSIONS

Neonates with underlying genetic abnormalities, hypoplastic left heart, or postoperative infection were at increased risk for extubation failure. A more conservative approach in these patients, including longer pre-extubation duration of antibiotic therapy for postoperative infections, may be warranted.

Resolution of airflow obstruction on polysomnography after laryngotracheal reconstruction with anterior tracheal wall suspension in a patient with DiGeorge Syndrome

DiGeorge Syndrome (DGS) may be associated with airway abnormalities including laryngomalacia and suprastomal collapse of the trachea (SCT), which may lead to sleep disordered breathing (SDB). We present a 4-year-old boy with DGS, SCT, and SDB by polysomnography (PSG) while the tracheostomy tube was capped. The patient underwent anterior tracheal wall suspension (ATWS) with concurrent tracheostomy decannulation. Following the repair, the patient experienced improved airway patency visually and by PSG with resolution of obstructive sleep apnea and hypoventilation. ATWS is an effective method to repair SCT in selected patients and may lead to early decannulation and improvement of SDB.

Dysphagia and disrupted cranial nerve development in a mouse model of DiGeorge (22q11) deletion syndrome

We assessed feeding-related developmental anomalies in the LgDel mouse model of chromosome 22q11 deletion syndrome (22q11DS), a common developmental disorder that frequently includes perinatal dysphagia – debilitating feeding, swallowing and nutrition difficulties from birth onward – within its phenotypic spectrum. LgDel pups gain significantly less weight during the first postnatal weeks, and have several signs of respiratory infections due to food aspiration. Most 22q11 genes are expressed in anlagen of craniofacial and brainstem regions critical for feeding and swallowing, and diminished expression in LgDel embryos apparently compromises development of these regions. Palate and jaw anomalies indicate divergent oro-facial morphogenesis. Altered expression and patterning of hindbrain transcriptional regulators, especially those related to retinoic acid (RA) signaling, prefigures these disruptions. Subsequently, gene expression, axon growth and sensory ganglion formation in the trigeminal (V), glossopharyngeal (IX) or vagus (X) cranial nerves (CNs) that innervate targets essential for feeding, swallowing and digestion are disrupted. Posterior CN IX and X ganglia anomalies primarily reflect diminished dosage of the 22q11DS candidate gene Tbx1. Genetic modification of RA signaling in LgDel embryos rescues the anterior CN V phenotype and returns expression levels or pattern of RA-sensitive genes to those in wild-type embryos. Thus, diminished 22q11 gene dosage, including but not limited to Tbx1, disrupts oro-facial and CN development by modifying RA-modulated anterior-posterior hindbrain differentiation. These disruptions likely contribute to dysphagia in infants and young children with 22q11DS.

[22Q11 microdeletion syndrome: cardiorespiratory symptoms and fibrobronchoscopy]

The 22q11 deletion syndrome is a frequent contiguous-gene deletion syndrome. This disorder has a broad spectrum of phenotypic manifestations. It includes various syndromes such as DiGeorge syndrome. The most frequent clinical manifestations are congenital cardiac defects, characteristic facies, palate malformations, hypoparathyroidism, immunodeficiency due to thymic hypoplasia, growth retardation, and behavioural and psychiatric problems. Among the symptoms observed, many patients suffer from respiratory insufficiency or failure. The origin is often multifactorial. Structural airway abnormalities are frequently found in this syndrome. In many of these patients the malformation is mild or non-existent, and remains asymptomatic. However, in some cases it can cause a severe respiratory insufficiency, being diagnosed when other disorders are ruled out. These cases illustrate the importance of early visualisation of the airway by fibrobronchoscopy in the management of the patient with 22q11 deletion syndrome who has recurrent respiratory difficulties.

Head and neck manifestations of 22q11.2 deletion syndromes

The allelic loss of 22q11.2 results in various developmental failures of pharyngeal pouch derivatives ("22q11.2 deletion syndromes", 22q.11DS), consequently affecting the anatomy and physiology of head and neck (H&N) organs. The objective of this paper was to describe those manifestations. Two 22q11.2DS patients with H&N manifestations were studied along with a comprehensive review of the English literature, from 1975 to 2010 regarding the associated H&N malformations among 22q11.2DS. A 24-year-old mentally disabled 22q11.2DS male presented with right hemithyroid enlargement, causing significant compressive signs. Sonography revealed a homogeneous 8 × 3 cm lesion, replacing almost the entire thyroid lobe. Fine needle aspiration revealed colloid material and abundant eosinophils. The hemithyroidectomy specimen confirmed follicular adenoma. A 19-year-old mentally disabled 22q11.2DS female underwent CT-angiography due to an upper GI bleeding. The study revealed a vascular malformation in the infratemporal fossa. Reviewing the reported data regarding 22q11.2DS-associated H&N malformations revealed abnormalities and malfunctions of the thyroid gland, parathyroid glands, thymus agenesis, cleft palate, carotid artery aberrations, malformations of the larynx and trachea and esophageal dysmotility. 22q11.DS patients may present with H&N anatomical abnormalities, along with hormonal dysfunctions, which require special awareness once treatment is offered, especially when concerning anesthetic and surgical aspects. In addition, hSNF5/INI1, a tumor suppressor gene, detected at location 22q11.2 was described to be "knocked out" in some patients. This may be associated with H&N tumors reported in these patients.

Genetic and environmental factors in the etiology of esophageal atresia and/or tracheoesophageal fistula: an overview of the current concepts

Esophageal atresia and/or tracheoesophageal fistula (EA/TEF) are severe congenital anomalies. Although recent years have brought significant improvement in clinical treatment, our understanding of the etiology of these defects is lagging. Many genes and genetic pathways have been implicated in the development of EA/TEF, but only a few genes have been shown to be involved in humans, in animals, or in both. Extrapolating data from animal models to humans is not always straightforward. Environmental factors may also carry a risk, but the mechanisms are yet to be elucidated. This review gives an overview of the current state of knowledge about both genetic and environmental risk factors in the etiology of EA/TEF.

Abnormal Sensorimotor Integrative Function of the Larynx in Congenital Laryngomalacia: A New Theory of Etiology

OBJECTIVES/HYPOTHESIS

Laryngomalacia is an enigmatic disease in which laryngeal tone is weak, resulting in dynamic prolapse of tissue into the larynx. Sensorimotor integrative function of the brainstem and peripheral reflexes are responsible for laryngeal tone and airway patency. The goal of this study was to elucidate the etiology of decreased laryngeal tone through evaluating the sensorimotor integrative function of the larynx. The secondary goal was to evaluate factors and medical comorbidities that contribute to the wide spectrum of symptoms and outcomes.

STUDY DESIGN

Prospective and retrospective collection of evaluative data on infants with congenital laryngomalacia at two tertiary care pediatric referral centers.

METHODS

Two hundred one infants with laryngomalacia were divided into three groups on the basis of disease severity (mild, moderate, severe). Patients were followed prospectively every 8 to 12 weeks until symptom resolution or loss to follow-up. Sensorimotor integrative function of the larynx was evaluated in 134 infants by laryngopharyngeal sensory testing (LPST) of the laryngeal adductor reflex (LAR) by delivering a duration- (50 ms) and intensity- (2.5-10 mm Hg) controlled air pulse to the aryepiglottic fold to induce the LAR. Medical records were retrospectively reviewed for medical comorbidities.

RESULTS

The initial LPST was higher (P < .001) in infants with moderate (6.8 mm Hg) and severe disease (7.4 mm Hg) compared with those with mild disease (4.1 mm Hg). At 1, 3, and 6 months, infants with moderate and severe disease continued to have a higher LPST compared with those with mild disease. At 9 months, the LPST decreased in all subjects (3.1-3.5 mm Hg, P = .14), which also correlated with symptom resolution. Neurologic, genetic, and cardiac diseases were more common in infants with severe disease (P < .001). Gastroesophageal reflux disease (GERD) and feeding problems more common in those with moderate and severe disease (P < .001). Apgar scores were lower in those with severe disease (P < .001). Most symptoms resolved within 12 months of presentation. Those with GERD benefited from treatment. Supraglottoplasty resulted in few complications. Multiple comorbidities (>3) influenced the need for tracheotomy.

CONCLUSIONS

Laryngeal tone and sensorimotor integrative function of the larynx is altered. The degree of alteration correlated with disease severity, indicating that factors that alter the peripheral and central reflexes of the LAR have a role in the etiology of signs and symptoms of laryngomalacia. GERD, neurologic disease, and low Apgar scores influenced disease severity and clinical course, explaining the spectrum of disease symptoms and outcomes. Sensorimotor integrative function improved as symptoms resolved.

The Respiratory System

One of the most critical events of birth is the conversion of the fluid-filled lung, unimportant to fetal intrauterine existence, into a hollow organ distended with air and capable of gaseous exchange sufficient to support life. Indeed, it has been argued that the major determinant of perinatal survival is respiratory function (Wigglesworth and Desai 1982).

The failure to make this conversion adequately may lead, directly or indirectly, to infant death, and the pathologist often needs to assess the contribution made by respiratory inadequacy to the sequence of events leading to death. In the preterm infant, problems are mainly related to pulmonary immaturity and associated therapy. In the mature infant, birth asphyxia primarily results in cerebral damage but can engender significant respiratory complications when associated with aspiration of meconium. Even in stillbirths, where primary pulmonary pathology is rarely a cause of death, lung pathology may provide clues to antecedent events. Poor lung growth and maturation may point to the presence of pathology elsewhere. Consequently, adequate pathological investigation of the fetal or infant respiratory system is critical in any perinatal autopsy.

Familial laryngomalacia in two siblings with syndromic features

We present two siblings with severe laryngomalacia requiring surgical intervention during the newborn period, microcephaly, developmental delay, cleft palate, preaxial polydactyly, dysplastic nails and conductive hearing loss (persistent after tympanostomy tube placement). In addition the girl has microopthalmia and the boy was born with a patent ductus arteriosus, mild pelviectasis, and hypospadias. This combination of multiple congenital anomalies has not been described previously and may represent a previously undescribed syndrome with autosomal inheritance.

FISH investigation of 22q11.2 deletion in patients with immunodeficiency and/or cardiac abnormalities

DiGeorge anomaly/velocardiofacial syndrome (DG/VCFS), called 22q11.2 deletion syndrome in general, is the most common chromosomal deletion syndrome found in humans. Typical facial features, palatal defects, conotruncal abnormalities of the heart, aplasia/hypoplasia of the parathyroid glands and of thymus are characteristics of this syndrome. Deletions of chromosome 22q11.2 (del22q11.2) are the leading causes of DG7VCFS. We report on a systematic search by fluorescence in situ hybridization (FISH) for deletions of chromosomes 22q11.2 in patients with a clinical suspicion or diagnosis of DG/VCFS. Using FISH we studied a series of 43 patients with suspected DG/VCFS. In this study, a total of 43 patients were investigated for the presence of a 22q11.2 deletion over a two-year period. Del22q11.2 was detected in 5 of the 43 patients tested. All patients with deletion had hypocalcemia, 80% had cardiac defects, 40% had facial dysmorphism, 40% had immunodeficiency , and 20% had otolaryngeal abnormalities. Chromosome 22q11.2 deletion is a relatively common condition and is readily diagnosed by FISH. We suggest that FISH analysis of 22q11.2 deletion should be performed in the presence of combined of hypocalcemia and congenital cardiac malformations, with or without any characteristics of the disease. This may facilitate an early diagnosis in such patients.

Retinoic acid signalling in the development of branchial arches

Branchial arches develop through a complex sequence of interactions between migrating cells, derived from neural crest and mesoderm, and epithelia of ectodermal and endodermal origin, to yield a variety of derivatives, notably skeletal elements, arteries and glands. In all vertebrate species, dramatic malformations generated by experimental blocks or activations of retinoic acid signalling highlight key roles for this molecule in the endoderm for branchial arch formation and morphogenesis.

Tracheobronchial intervention in children

Disorders of the major airways in children are often difficult to treat. Recent advances in interventional radiology are proving useful, for both assessment of the severity of the problem and treatment. Flexible bronchoscopy and bronchography are essential tools for diagnosis, intervention and follow-up. Echocardiography, computed tomography and magnetic resonance imaging may also be important for the evaluation of cardiovascular anomalies, which are often associated with airway obstruction. Surgery remains the first line of treatment for most congenital abnormalities of the airway and for cardiac anomalies that cause airway compression. Balloon dilatation and stenting are helpful in certain other conditions, as well as in children whose airway problem is not fully corrected by surgery. A multidisciplinary approach is required, with input from pediatric cardiothoracic surgeons, radiologists, radiographers, otolaryngologists, pulmonologists, anesthesiologists, intensivists, physiotherapists and liaison nurses.

Long-term complications of congenital esophageal atresia and/or tracheoesophageal fistula

Congenital esophageal atresia (EA) and/or tracheoesophageal fistula (TEF) are common congenital anomalies. Respiratory and GI complications occur frequently, and may persist lifelong. Late complications of EA/TEF include tracheomalacia, a recurrence of the TEF, esophageal stricture, and gastroesophageal reflux. These complications may lead to a brassy or honking-type cough, dysphagia, recurrent pneumonia, obstructive and restrictive ventilatory defects, and airway hyperreactivity. Aspiration should be excluded in children and adults with a history of EA/TEF who present with respiratory symptoms and/or recurrent lower respiratory infections, to prevent chronic pulmonary disease.

Esophageal atresia and tracheo-esophageal fistula in a patient with Digeorge syndrome

DiGeorge Syndrome (DGS) is a congenital disorder that affects the thymus, parathyroid glands, and heart and brain. Thymus involvement in DGS may vary between absence/hypoplasia of thymus to various forms of reduced T cell function. TBX1 deficiency causes a number of distinct vascular and heart defects, suggesting multiple roles in cardiovascular development, specifically, formation and growth of the pharyngeal arch arteries, growth and septation of the outflow tract of the heart, interventricular septation, and conal alignment. Here the authors describe a case of DGS presenting with severe combined immunodeficiency, esophageal atresia, and tracheoesophageal fistula (TEF). DGS is an important differential diagnosis in TEF.