The role of magnetic resonance imaging in the assessment of suspected extrinsic tracheobronchial compression due to vascular anomalies

Chronic respiratory disorders due to aberrant innominate artery: a case series and critical review of the literature

BACKGROUND

Tracheal compression (TC) due to vascular anomalies is an uncommon, but potentially serious cause of chronic respiratory disease in childhood. Vascular slings are congenital malformations resulting from abnormal development of the great vessels; in this group of disorders the most prevalent entity is the aberrant innominate artery (AIA). Here we provide a report on diagnosis and treatment of AIA in nine children with unexplained chronic respiratory symptoms. We describe the cases, perform a literature review, and provide a discussion on the diagnostic workup and treatment that can help manage AIA.

METHODS

Clinical history, diagnostic procedures and treatment before and after the AIA diagnosis were retrospectively reviewed in nine children (5 boys and 4 girls), who were referred for recurrent-to-chronic respiratory manifestations over 10 years (2012-2022). We performed a comprehensive report on the ongoing clinical course and treatment as well as an electronic literature search on the topic.

RESULTS

Diagnoses at referral, before AIA was identified, were chronic dry barking cough associated with recurrent pneumonia (n = 8, 89%), lobar/segmental atelectasis (n = 3, 33%), atopic/non atopic asthma (n = 3, 33%); pneumomediastinum with subcutaneous emphysema complicated the clinical course in one case. When referred to our Unit, all patients had been previously treated with repeated antibiotic courses (n = 9, 100%), alone (n = 6, 67%) or combined with prolonged antiasthma medications (n = 3, 33%) and/or daily chest physiotherapy (n = 2, 22%), but reported only partial clinical benefit. Median ages at symptom onset and at AIA diagnosis were 1.5 [0.08-13] and 6 [4-14] years, respectively, with a relevant delay in the definitive diagnosis (4.5 years). Tracheal stenosis at computed tomography (CT) was ≥ 51% in 4/9 cases and ≤ 50% in the remaining 5 subjects. Airway endoscopy was performed in 4 cases with CT evidence of tracheal stenosis ≥ 51% and confirmed CT findings. In these 4 cases, the decision of surgery was made based on endoscopy and CT findings combined with persistence of clinical symptoms despite medical treatment. The remaining 5 children were managed conservatively.

CONCLUSIONS

TC caused by AIA may be responsible for unexplained chronic respiratory disease in childhood. Early diagnosis of AIA can decrease the use of expensive investigations or unsuccessful treatments, reduce disease morbidity, and accelerate the path toward a proper treatment.

Rings and Slings: Not Such Simple Things

Purpose of Review

Vascular rings are congenital malformations resulting from abnormal development of the great vessels, with the consequent encircling and compression of the trachea, esophagus, or both. We conducted a review of the current literature to identify the different management strategies that can be implemented based on the prognosis of each of these anomalies.

Recent Findings

Although most vascular rings occur in isolation, they can also be associated with other congenital cardiac and/or respiratory diseases; therefore, thorough investigation is necessary before definitive surgical repair. Clinical presentation varies from asymptomatic to severe, with both respiratory and digestive symptoms. Although early surgical results are acceptable, the long-term outcome is variable; therefore, there is still controversy regarding the appropriate timing of treatment. This is especially true with regard to the Kommerell diverticulum (KD) and in patients without symptoms at the time of initial surgical evaluation.

Summary

As more sophisticated diagnostic tools have become available and more studies on adults affected by this condition have been published, understanding of this condition and its additional clinical implications has grown and appears to be tilting management toward earlier intervention.

Diagnostic Accuracy of Three-dimensional Turbo Field Echo Magnetic Resonance Imaging Sequence in Pediatric Tracheobronchial Anomalies with Congenital Heart Disease

Tracheobronchial anomalies are common in congenital heart disease (CHD), including tracheobronchial stenosis, tracheal bronchus, cardiac bronchus, and bronchial isomerism, which can cause varying degrees of respiratory illness. It is necessary to assess tracheobronchial anomalies and make a preoperative airway evaluation. Multi-slice computed tomography (MSCT) and cardiac magnetic resonance imaging (MRI) are the most effective noninvasive modalities for the diagnosis of CHD and the associated tracheobronchial anomalies. However, MSCT remains an ionizing procedure despite using low dose protocols. The aim of this study was to evaluate diagnostic accuracy of tracheobronchial anomalies in patients with CHD using three-dimensional turbo field echo(3D-TFE) magnetic resonance imaging sequence for preoperative airway evaluation. The results indicated that 3D-TFE provided better image quality as compared to that of 3D-balanced turbo field echo (3D-bTFE), and it can clearly demonstrated the tracheobronchial tree and tracheobronchial anomalies in CHD. This study confirms the clinical value of 3D-TFE in diagnosing tracheobronchial anomalies and supply helpful tracheobronchial information for preoperative strategies and postoperative follow-up.

Neonatal magnetic resonance imaging in double aortic arch diagnosed prenatally by ultrasound

Congenital double aortic arch (DAA) is an uncommon vascular anomaly; however, its prenatal detection is associated with congenital heart defects and chromosomal abnormalities, including 22q11 deletion. We present a case of DAA diagnosed prenatally. DAA can be diagnosed by prenatal ultrasound in the transverse three vessel-trachea view, which shows a trident image formed by a complete vascular ring and the ductus arteriosus. Postnatal magnetic resonance images in this view correlate well with prenatal ultrasound images and help in confirmation of diagnosis, evaluation of the risk of airway or esophageal compression, and planning of surgery.

Mild tracheal compression by aberrant innominate artery and chronic dry cough in children

BACKGROUND

In children with aberrant innominate artery (AIA) one of the most prevalent respiratory symptom is dry cough. How frequently this mediastinal vessels anomaly, that can induce tracheal compression (TC) of different degree, may be detected in children with chronic dry cough is not known.

METHODS

In a 3-year retrospective study, the occurrence of mediastinal vessels abnormalities and the presence and degree of TC was evaluated in children with recurrent/chronic dry cough.

RESULTS

Vascular anomalies were detected in 68 out of the 209 children evaluated. A significant TC was detected in 54 children with AIA, in eight with right aortic arch, in four with double aortic arch but not in two with aberrant right subclavian artery. In AIA patients, TC evaluated on computed tomography scans, was mild in 47, moderate in six and severe in one. During bronchoscopy TC increased in expiration or during cough, but this finding was more pronounced in children with right aortic arch and double aortic arch in which a concomitant tracheomalacia was more evident. Comorbidities were detected in 21 AIA patients, including atopy, reversible bronchial obstruction and gastroesophageal reflux. Aortopexy was performed in eight AIA patients, while the remaining AIA patients were managed medically and showed progressive improvement with time.

CONCLUSION

Mild TC induced by AIA can be detected in a sizeable proportion of children with recurrent/chronic dry cough. The identification of this anomaly, that may at least partially explain the origin of their symptom, may avoid further unnecessary diagnostic examinations and ineffective chronic treatments.

Imaging modalities in children with vascular ring and pulmonary artery sling

PURPOSE

Our aim is to compare new non-invasive imaging modalities in the evaluation of vascular ring (VR) and pulmonary artery sling (PAS) and to understand the role of bronchoscopy in comparison with them in assessing tracheobronchial tree.

METHODS

We have retrospectively analyzed the data from 41 patients with a VR or a PAS diagnosed at Bambino Gesù Children's Hospital of Rome, between 2008 and 2012. Age, gender, presenting symptoms, clinical history, comorbidities, imaging modalities used for diagnosis (cardiac magnetic resonance [CMR], computed tomography [CT], tracheobronchoscopy [TB]) and surgical treatment were recorded.

RESULTS

The vascular anatomy was completely defined in all patients, whether evaluated by CMR or CT, with a diagnostic accuracy of 100% based on surgical observation. All CT exams were performed without sedation with a mean dose-length product (DLP32 ) of 29 ± 9 and an effective dose of 1.56 ± 0.6 mSv, range 0.5-2.5 mSv. CMR required general anesthesia in all patients but involved no exposure to ionizing radiation. CT performed better than CMR in assessing tracheal stenosis when compared to TB. It detected complete tracheal cartilage rings in 2/3 patients with PAS, besides tracheomalacia and/or bronchomalacia in 54% of patients.

CONCLUSIONS

Both cross-sectional imaging modalities (CT and CMR) can reliably and accurately diagnose these congenital vascular anomalies. While CT involves exposure to ionizing radiation, it avoids the risks related to anesthesia needed for CMR, and provides a more accurate assessment of tracheobronchial anatomy. TB remains a fundamental tool in tracheomalacia diagnosis in VR symptomatic patients and PAS.

Kommerell's diverticulum in the current era: a comprehensive review

Kommerell's diverticulum is a developmental error with a remnant of fourth dorsal aortic arch, named after Dr. Kommerell, a radiologist, who made the first diagnosis in a living individual. The diverticulum can occur in both the left and right aortic arch, from which an aberrant subclavian artery rises to the contralateral side. Pediatric patients often present with airway symptoms whereas dysphagia and chest discomfort are more common in the adult patients. Computed tomography or magnetic resonance imaging can provide details of the diverticulum, associated arch anomalies, and its relationship with surrounding organs. Recent histological studies indicated the presence of cystic medial necrosis in the diverticulum wall, which would explain the reported high rates of aortic dissection and rupture associated with the diverticulum. Accumulated knowledge on this entity and the recent advancement of imaging techniques, surgical/endovascular strategies, and perioperative management, have led to more aggressive intervention to the diverticulum in the early phase. While still under debate it is generally accepted to consider surgical intervention when the diameter of the diverticulum orifice exceeds over 30 mm, and/or the diameter of the descending aorta adjacent to the diverticulum exceeds over 50 mm. Treatment options include open surgical repair, hybrid endovascular repair, and total endovascular repair. The selection of treatment strategy for Kommerell's diverticulum should be based on the anatomy, comorbidities of the patient, and surgical expertise available. The summaries of open and endovascular repairs of over 210 cases from literature search from 2004 to 2014 are also provided in this review.

Vascular rings and slings: interesting vascular anomalies

Introduction:

A vascular ring refers to encirclement of the trachea and oesophagus by an abnormal combination of derivatives of the aortic arch system. These malformations can cause variable degrees of compression of the oesophagus, trachea or both. Symptoms can range from no effect to severe stridor, dyspnoea and/or dysphagia.

Method and results:

This study presents a case series of six patients treated over a six-year period (2003–2009), illustrating the features of four different types of vascular ring; these types are discussed in detail. The clinical presentation, radiology, and microlaryngoscopy and bronchoscopy findings are also discussed.

Conclusion:

The management of children with vascular rings requires a high index of clinical suspicion to ensure prompt diagnosis. As many of these children present with airway symptoms, the paediatric otolaryngologist plays a key role in identifying and assessing their anatomical anomalies.

CT demonstration of "chicken trachea" resulting from complete cartilaginous rings of the trachea in ring-sling complex

We report a 10-month-old infant who presented with tetralogy of Fallot and respiratory disease in whom the suspicion of a ring-sling complex was confirmed by high-resolution CT. CT demonstrated the typical association of left pulmonary artery sling and the "chicken trachea" resulting from complete cartilaginous rings of the trachea.

Airway stents in children

Airway obstruction in children is a rare, but difficult clinical problem, with no clear agreement on optimal therapeutic approach. Stenting of the airway has been used successfully in adults, and is an attractive alternative in children. Fundamental differences of pediatric compared to adult use include the benign nature of most stenoses, the narrow and soft airways of children, the required long-term tolerance and adaptation to growth. These differences may significantly alter the therapeutic balance, calling into question the precise role stents play in the treatment of airway obstruction in children. Stent placement can be technically demanding but is not exceedingly difficult. Experience is necessary to select the proper size and type of stent. Metal stents usually achieve airway patency and clinical improvement in the majority of cases, while this is less frequently the case with silicone stents. Some complications such as granulation and secretion retention seem to occur in most children after stent implantation. Unfortunately, severe complications including death have been reported in a significant proportion of children. Stent related mortality can be estimated at 12.9% from published data, but these include complication centered reports. The initial euphoria for airway stents in children has largely abated and most authors agree that they should only be employed in circumstances with no good alternatives. It is crucial that all surgical and medical alternatives are considered and the decision to place a stent is not made because other options are overlooked or not available locally. Stent use in a palliative setting has also been reported and is probably reasonable. Stents will only allow limited adaptation for the growth of pediatric airways by balloon dilatation. All metal stents should be considered as potentially permanent, and removal sometimes may only be possible through a surgical and sometimes risky approach.

Unilateral lung agenesis--detrimental roles of surrounding vessels

Unilateral lung agenesis is a rare congenital defect and could be associated with multiple abnormalities. The patients usually have poor long-term outcomes especially in those with right lung agenesis. We reviewed the 10-year experience in our hospital to describe special clinical features and try to delineate the causes of poor outcomes. From 1995 to 2005, 14 patients less than 18 years of age with unilateral lung agenesis (4 with left agenesis, 10 with right agenesis) were enrolled. Medical records reviewed included diagnosis, presentation, chromosome anomalies, cardiovascular anomalies and interventions, outcomes. We found that the mechanisms of severe airway disease in right lung agenesis included (1) trachea compression by the aortic arch, (2) the presence of "pseudo-ring-sling complex," (3) distended pulmonary artery due to left to right shunt which impinged the only bronchus, and finally (4) the persistent LSVC that restricts the growth of trachea. The etiologies of airway complication in left lung agenesis included anomalous aortic arch compression on trachea and the coexisting heart disease with significant left to right shunt, which impinged on the bronchus. In conclusion, unilateral lung agenesis has frequently associated airway problems due to its surrounding vessels. Satisfactory airway intervention remains challenging. This disease still requires great effort to improve patient outcomes.