The triad of bridging bronchus malformation associated with left pulmonary artery sling and narrowing of the airway: the legacy of Wells and Landing

Bridge bronchus and pulmonary artery sling: Case report and literature review

We present the case of a 14-year-old adolescent boy with a history of poorly controlled asthma and a final diagnosis of a bridge bronchus associated with sling of the left pulmonary artery. Regarding the case report, we describe the characteristic findings in computerized tomography multidetector of the thorax, its classification, and the most relevant information about this malformation. Congenital malformations of the tracheobronchial tree may occur in the context of asymptomatic or symptomatic respiratory patients. These malformations may be associated with other vascular, tracheal, and syndromes with multiorgan involvement. Although most patients are asymptomatic, some of them will have nonspecific symptoms without a clear etiology or will be diagnosed incidentally during the diagnostic evaluation of other pathologies. It is important to know and recognize the normal anatomy and its variations, since radiology undoubtedly plays a fundamental role in the diagnosis and preoperative assessment of these malformations, which although they have low incidence, must be identified in a timely manner by the specialist in diagnostic images.

Morphologic classification of tracheobronchial arborization in children with congenital tracheobronchial stenosis and the associated cardiovascular defects

Background

We sought to classify patients with congenital tracheal stenosis (CTS) according to tracheobronchial morphology and determine anatomic features associated with tracheobronchial anomalies (TBAs) and concurrent cardiovascular defects (CVDs).

Methods

We enrolled 254 patients who underwent tracheoplasty between November 1, 2009 and December 30, 2018. The anatomic features of the tracheobronchial tree and cardiovascular system were abstracted from bronchoscopy, echocardiography, computerized tomography, and operative reports.

Results

Four types of tracheobronchial morphology were identified: Type-1, which included normal tracheobronchial arborization (Type-1A, n = 29) and tracheal bronchus (Type-1B, n = 22); Type-2 (tracheal trifurcation; n = 49), and Type-3 (typical bridging bronchus; n = 47). Type-4 (bronchus with an untypical bridging pattern) was divided into Type-4A (involving bronchial diverticulum; n = 52) and Type-4B (absent bronchus; n = 55). Carinal compression and tracheomalacia were significantly more frequent in Type-4 patients than in the other patients (P < 0.01). CVDs were common in patients with CTS, especially in patients with Type-3 and Type-4 (P < 0.01). Persistent left superior vena cava was most common among patients with Type-3 (P < 0.01), and pulmonary artery sling was most frequent among those with Type-4 (P < 0.01). Outflow tract defects were most likely to occur in Type-1B. Early mortality was detected in 12.2% of all patients, and young age (P = 0.02), operation in the early era (P < 0.01), and bronchial stenosis (P = 0.03) were proven to be risk factors.

Conclusions

We demonstrated a useful morphological classification for CTS. Bridging bronchus was most closely linked with vascular anomalies, while tracheal bronchus was frequently associated with outflow tract defects. These results may provide a clue to CTS pathogenesis.

Pediatric large airway imaging: evolution and revolution

Infants and children often present with respiratory symptoms referable to the airway. For these pediatric patients, airway imaging is frequently performed to evaluate for underlying disorders of the large airway. Various imaging modalities have been used to evaluate the pediatric large airway, and pediatric airway imaging techniques have continued to evolve. Therefore, clear understanding of the status and new advances in pediatric large airway imaging is essential for practicing radiologists to make timely and accurate diagnoses, which can lead to optimal pediatric patient management.

Lung volume determination by dual-source computed tomography in infants with pulmonary artery sling: a case-control study

BACKGROUND

Pulmonary artery sling (PAS) is associated with tracheal stenosis and left pulmonary artery (LPA) dysplasia in infants, both developmental abnormalities that may lead to pulmonary hypoplasia and lung volume changes. As such, we aimed to monitor the effects of tracheal stenosis and pulmonary vascular malformation on lung volumes in infants with PAS and their correlation with lung volumes in infants with PAS using dual-source computed tomography (DSCT).

METHODS

A case-control study was performed. From May 2009 to June 2017, we retrospectively enrolled patients with surgically confirmed PAS and compared them to matched normal controls (A healthy control group comprising age- and gender-matched patients with adequate imaging data was used for the comparisons.). All the patients underwent DSCT examinations. We measured and compared the diameters of the trachea, main bronchus, and main pulmonary artery (MPA) and its branches, and both lung volumes on the axial, and reconstructed CT images.

RESULTS

There were no statistical differences in the diameters of the MPA or right pulmonary artery (RPA) between patients (N=15) and controls (N=28). The diameter of the main bronchus, the bilateral trachea and the left pulmonary artery were all smaller in the PAS group than in the control group, and significant differences were evident in the left lung volume the right lung volume, and the right-to-left lung volume ratio between the 2 groups. Pearson's correlation and linear regression analyses between the diameters of the trachea and MPA, total lung volume, ipsilateral bronchial and pulmonary artery branches, and ipsilateral lung volume ranged from 0.71 to 0.87 and 0.57 to 0.77 for the control and PAS groups, respectively.

CONCLUSIONS

Tracheal stenosis and LPA dysplasia in infants with PAS cause alterations in lung tissue morphology and physiological development, resulting in reduced bilateral lung volumes.

Left Pulmonary Artery Sling: Postoperative Outcomes for Patients at a Single Center

BACKGROUND

Left pulmonary artery (LPA) sling is a rare anomaly characterized by the origin of the LPA from the right pulmonary artery with a course between the trachea and esophagus. It is often associated with airway and cardiac anomalies.

METHODS

This is a retrospective case series of consecutive patients who underwent LPA sling repair (LPASR) at a tertiary care center over a 35-year period with a focus on tracheal and/or LPA reinterventions and survival.

RESULTS

Between June 1983 and July 2018, 42 patients were identified: isolated LPASR was performed in 16 (38%), LPASR/intracardiac repair in 10 (24%), and LPASR/tracheal repair in 16 (38%). There were 5 (12%) in-hospital and 4 (10%) late deaths. Survival rates (15 years) were as follows: 100% (isolated LPASR), 65% (concomitant intracardiac repair), and 52% (concomitant tracheal surgery). Preoperative intensive care unit (ICU) hospitalization was associated with future intervention on the LPA/trachea (61%, 11/18). The median distribution of blood flow to the left lung post-index surgery was 38%. Freedom from isolated LPA intervention was 100% after isolated LPASR, 93% after LPASR/tracheal surgery, and 69% after LPASR/intracardiac repair. Freedom from isolated tracheal intervention was 92% after isolated LPASR, 73% after LPASR/tracheal surgery, and 78% after LPASR/intracardiac repair.

CONCLUSIONS

ICU hospitalization prior to index surgery may indicate the severity of associated cardiac/tracheal abnormalities as this is associated with increased morbidity and mortality. Patients who underwent LPASR/intracardiac surgery were more likely to undergo isolated LPA intervention and those who underwent LPASR/tracheal surgery were more likely to undergo isolated tracheal intervention.

Vascular rings

Vascular rings are congenital aortic arch anomalies that lead to compression of the trachea or esophagus. The goal of this review is to summarize our current recommendations for the management of patients with a diagnosis of a vascular ring. We review the history, classification methods, and epidemiology of the various types of vascular rings. We then propose a management strategy for the relatively new paradigm of fetal diagnosis, including the management of asymptomatic vascular rings. Finally, we finish with a review of the operative techniques and outcomes for the four main categories of vascular rings.

Cardiopulmonary bypass as a bridge for bronchial foreign body removal in a child with pulmonary artery sling: A case report

RATIONALE

Successful removal of an airway foreign body (FB) in some intractable cases can be very challenging, because of tracheal anomalies, unstable respiratory status of the patients, and the location of FB. The use of cardiopulmonary bypass (CPB) support for the treatment of a FB is extremely rare.

PATIENT CONCERNS

We present a case of a 39-month-old previously healthy girl who was admitted to our hospital for suspected FB aspiration (FBA). Initially, the attempt for removal of the FB by conventional bronchoscopy failed because of hypoxic intolerance.

DIAGNOSES

Bronchoscopy revealed tracheal anomalies and subsequent computed tomography angiography demonstrated the presence of a pulmonary artery sling (PAS), which confirmed the diagnosis of PAS accompanied with FBA.

INTERVENTIONS

With the assistance of CPB, multidisciplinary treatment involving the respiratory, cardiothoracic and anesthetic teams were involved and the bronchial FB was removed by flexible bronchoscopy successfully and then PAS was corrected by surgical intervention.

OUTCOMES

The patient remained asymptomatic, without shortness of breath or wheezing during the 15 months follow-up.

LESSONS

This case highlights that in a complicated case of FBA, bronchoscopy and computed tomography imaging are of great importance to achieve an accurate diagnosis, and a multidisciplinary treatment approach is essential for a satisfactory outcome. If the patient is unstable for bronchoscopy, CPB can be temporarily used in the stabilization of the patient to allow safe removal of the FB.

Tracheoplasty for Patients with Pulmonary Artery Sling and Tracheal Stenosis: A Meta-Analysis

We performed this meta-analysis to assess the safety and efficacy of tracheoplasty for patients with pulmonary artery sling (PAS) and tracheal stenosis. Published studies that included surgical treatment of PAS and tracheal stenosis with and without tracheoplasty were identified by searching the PubMed, EMBASE, and Cochrane Library databases until May 2020. The outcomes assessed included postoperative ventilation time, early and late mortality, and follow-up respiratory symptoms. The mean difference (MD)/risk ratio (RR) with 95% confidence intervals (CI) was estimated with a random-effects/fixed-effects model. Subgroup analysis was performed stratified by percentage of patients with tracheal rings. A total of eight studies comprising 219 patients with PAS accompanied by tracheal stenosis were included. The pooled estimates of postoperative ventilation time (MD 17.68, 95% CI 6.38 to 28.98, p < 0.01) and early mortality (RR 3.93, 95% CI 1.55 to 9.95, p < 0.01) favored the repair-only group. Late mortality (RR 1.33, 95% CI 0.48 to 3.68, p = 0.58) and respiratory symptoms (RR 1.51, 95% CI 0.50 to 4.57, p = 0.47) at follow-up showed no significant differences between the groups with repair-only and repair with tracheoplasty. The same results were found in subgroup analyses. For the surgical treatment of PAS with tracheal stenosis, repair without tracheoplasty appears to result in shorter postoperative ventilation time and lower early mortality, with no increase in late mortality or respiratory symptoms at follow-up, compared with concomitant tracheoplasty.

The bridging bronchus: A comprehensive review of a rare, potentially life-threatening congenital airway anomaly associated with cardiovascular defects

The bridging bronchus is a rare congenital airway anomaly in which the right upper lobe of the lung is supplied by the right main bronchus while the right lower lobe, and often the right middle lobe is supplied by an aberrant bronchus arising from the left main bronchus. The aberrant bronchus crosses (bridges) the lower part of the mediastinum, hence the term bridging bronchus (BB). This potentially life-threatening condition, usually accompanied by diffuse or focal airway stenosis, commonly presents with signs and symptoms related to large airway obstruction, such as respiratory distress, apnea, wheezing, stridor, and recurrent respiratory tract infections. Diagnosis of the BB is often challenging because the associated signs and symptoms mimic those of common conditions such as bacterial and viral bronchiolitis, bronchial asthma, cystic fibrosis, and foreign body aspiration. The BB is also often accompanied by congenital cardiovascular anomalies, including left pulmonary artery sling, atrial, and ventricular septal defects, tetralogy of Fallot, patent ductus arteriosus, and coarctation of the aorta. Patients presenting with the above signs and symptoms who are not responsive to standard treatment modalities, and have accompanying cardiovascular congenital anomalies should, therefore, be investigated for the BB. Herein, we review the anatomy, embryology, clinical presentation, differential diagnosis, imaging techniques and surgical management of the BB.

Surgical treatment of pulmonary artery sling and tracheal stenosis with or without tracheoplasty: A protocol for a systematic review and meta-analysis

BACKGROUND

Pulmonary artery sling (PAS) is rare, often with tracheal stenosis. And the postoperative mortality is high. For now, there is no consensus on the tracheoplasty for the patients with PAS and tracheal stenosis.

METHODS

Studies involving surgical repair of PAS and tracheal stenosis with and without tracheoplasty were identified by searching the PubMed, EMBASE, and the Cochrane Library databases until June 5, 2019. The assessed variables included ventilation time, early and late mortality, and symptom at follow-up. A random-effect/fixed-effect model was used to summarize the estimates of the mean difference (MD)/risk ratio (RR) with 95% confidence interval (CI).

RESULTS

This study will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will assess the safety and efficacy of tracheoplasty for patients with PAS and tracheal stenosis, and provide more evidence-based guidance in clinical practice.

PROSPERO REGISTRATION NUMBER

CRD42019139788.

Congenital pulmonary vascular anomalies

Congenital pulmonary vascular anomalies are typically found in infancy or early childhood however, some may remain silent and present in adult patients. Anomalies may be separated into anatomic categories based on involvement of the pulmonary arteries, pulmonary veins or both with or without involvement of the lung parenchyma. Association with congenital heart disease and other syndromes is very common. Computed tomography (CT) and magnetic resonance imaging (MRI) are both invaluable at assessment of these anomalies allowing for both diagnosis and detailed treatment planning. This article will focus primarily on the use of CT, as the high resolution evaluation of the lung parenchyma is also important in many of these conditions. In young patients especially, rapid heart rate and concerns of radiation exposure are important considerations when performing CT. This article will discuss scan techniques as well as clinical diagnostic considerations and basic endovascular treatment of congenital pulmonary vascular anomalies.

Pediatric Thoracic Anatomic Variants: What Radiologists Need to Know

Anatomic variants are common incidental findings in pediatric chest imaging and can be mistaken for true underlying pathology, sometimes resulting in unnecessary additional imaging evaluation or invasive procedures. Clear understanding of the imaging characteristics and clinical significance of anatomic thoracic variants is important for accurate diagnosis and avoidance of unnecessary intervention. This article provides an up-to-date review of anatomic variants in the pediatric chest to increase knowledge and aide in timely, correct diagnosis.

Sling Pulmonary Artery with Bridging Bronchus and Narrowing Airway: A Case Report

We present a case of a 10-month-old girl baby with pulmonary artery sling and bridging bronchus demonstrated using multidetector computed tomography with a three-dimensional volume-rendering display and minimum intensity projections. To the best of our knowledge, this method has been helpful not only in the diagnosis and surgical planning for this rare abnormality but also in the evaluation of prognosis. After pulmonary artery reimplantation, the patient was well and discharged.

Evaluation of left pulmonary artery sling, associated cardiovascular anomalies, and surgical outcomes using cardiovascular computed tomography angiography

We evaluated the prevalence, image appearance, associated cardiovascular anomalies, and surgical outcomes of left pulmonary artery sling (LPAS) using cardiovascular computed tomography angiography (CCTA). A retrospective search of patients from our database between October 2007 and December 2014 identified 52,200 patients with congenital heart diseases (CHD) referred for CCTA, echocardiography, or magnetic resonance imaging. Clinical information, CCTA findings, associated cardiovascular anomalies, and surgical outcomes were analyzed. We showed a hospital-based prevalence of 71 patients with LPAS (0.14%, 71/52,200) among CHD patients. Of these, 47 patients with CCTA examinations were assessed further. Most patients (40/47, 85%) had associated cardiovascular anomalies, of which ventricular septal defects (22/47, 47%), atrial septal defects (20/47, 43%), patent ductus arteriosus (16/47, 34%), persistent left superior vena cava (14/47, 30%), and abnormal branching of the right pulmonary artery (ABRPA) (14/47, 30%) were most commonly identified. In total, 28 patients underwent LPA reanastomosis and/or tracheoplasty in our center, and 5 died. LPAS had a hospital-based prevalence of 0.14% among CHD patients. ABRPA is not uncommon and must be recognized. CCTA is a feasible method for demonstrating LPAS and its associated cardiovascular anomalies for an optimal pre-operative assessment of LPAS.

Bridging bronchus: Importance of recognition on airway endoscopy

Bridging bronchus is an anomalous bronchus, which crosses the mediastinum from the contralateral mainstem bronchus and it is commonly associated with congenital great vessel abnormalities. This is a case report of an infant that underwent airway endoscopy and attempt at cannulation of a mainstem bronchus with supposed bronchial cast after cardiac surgery in the intensive care unit. After multiple failed attempts, further workup was completed which revealed a bridging bronchus. A bridging bronchus must be suspected in a patient with abnormal appearing endoscopy in presence of great vessel anomalies to prevent accidental injury to the tracheobronchial tree.

Congenital vascular rings: a clinical challenge for the pediatrician

Vascular rings are congenital anomalies that lead to variable degrees of respiratory problems or feeding difficulties by forming a complete or partial ring compressing the trachea, the bronchi, and the esophagus. The clinical diagnosis of vascular rings is often challenging for the pediatrician because the clinical manifestations are heterogeneous and nonspecific. Symptoms can vary from wheezing, stridor, dyspnea, and/or dysphagia to life-threatening conditions; however, they may not be present. The aim of this study is to review the recent literature on this subject and describe new developments in diagnostics and imaging.

Is tracheoplasty necessary for all patients with pulmonary artery sling and tracheal stenosis?

Pulmonary artery sling frequently accompanies various degrees of tracheal stenosis. The authors reviewed their surgical outcomes for pulmonary artery sling from two institutions. From 1997 to September 2011, 16 patients with pulmonary artery sling underwent surgical treatment. Their median age was 4.6 months and their body weight 6.2 kg at the time of the operation. Of the 16 patients, 12 showed preoperative respiratory symptoms such as recurrent airway infection or dyspnea, with three of these patients receiving ventilator therapy preoperatively. Most of the patients showed various degrees of tracheal luminal stenosis and stenotic length, except for three patients who did not show significant airway stenosis. Left pulmonary artery reimplantation was performed for all the patients, but an accompanying tracheoplasty was performed for only two patients (one patch augmentation and one sliding tracheoplasty). After surgery, early extubation and intensive lung care were performed. Two operative mortalities occurred: one due to cardiac tamponade associated with postoperative bleeding and one due to aggravation of preexisting multiorgan failure. Two late mortalities occurred: one due to airway obstruction by repetitive granulation tissue growing at the tracheoplasty site and one due to pneumonia. The 12 living patients, including 11 patients who did not undergo tracheal surgery, showed no clinically significant airway problems at their last follow-up visit. The surgical outcomes for pulmonary artery sling without tracheoplasty were acceptable. The authors think tracheoplasty may be avoided by intensive postoperative airway management for a significant portion of the patients with pulmonary artery sling and tracheal stenosis.

Bridging bronchus--a rare cause of recurrent wheezy bronchitis

Background

Wheezing is a common symptom in infants and toddlers. Usually it occurs due to viral infection of the lower airways and no further diagnostic procedures are necessary. However in rare cases, other reasons such as anatomical malformation have to be considered.

Case presentation

We report about an infant with recurrent episodes of wheezy bronchitis, which persisted despite adequate therapy. Bronchoscopy and computed tomography of the lung with three-dimensional reconstruction revealed a rare bronchial branching anomaly - the so called “bridging bronchus”. In contrast to previous case reports, this infant showed no additional malformations, which seems to be important for the prognosis.

Conclusion

To the best of our knowledge this is the first report about a patient with a bridging bronchus in its “original form” without associated anomalies of the trachea-bronchial system or other organs.