Angiography and Dynamic Airway Evaluation with MDCT in the Diagnosis of Double Aortic Arch Associated with Tracheomalacia

Routine multi detector computed tomography evaluation of tracheal impairment compared to laryngo-tracheal endoscopy in children with vascular ring

PURPOSE

The aim of this study is to compare free-breathing routine multi detector computed tomography (MDCT) and laryngo-tracheal (LT) flexible endoscopy in the evaluation of tracheal impairment in children with vascular ring (VR).

MATERIALS AND METHODS

We performed a retrospective and monocentric study of all patients with VR from 1997 to 2014. Clinical data included: initial symptoms, type of surgery and clinical outcome. MDCT were blindly reviewed by two radiologists in consensus, independently of LT endoscopy results. Radiologic and endoscopic results were reviewed according to four criteria: percentage of tracheal narrowing, distance of the compression from carina, presence of bronchial compression and signs of tracheomalacia (TM). Concordance was evaluated for each criterion with a Spearman coefficient.

RESULTS

From 1997 to 2016, 21 patients with a vascular ring were operated on, among which 57% by thoracoscopy: double aortic arch (n = 14), Neuhauser anomaly (n = 4) and Right aorta + aberrant right subclavian artery (n = 3). 90% of them presented with respiratory symptoms among which 43% of stridor. Chest X-ray was suggestive of VR in 87% of the cases. MDCT images and LT endoscopy results were available and analyzed for nine patients. Concordance (Spearman correlation coefficient) was excellent for percentage and level of tracheal narrowing (1) and good for TM (0.79).

CONCLUSION

Free breathing routine MDCT is a reliable exam compared to LT endoscopy in the evaluation of tracheal impairment in children with VR. In case of respiratory symptoms (except stridor) and suggestive chest X-ray of VR, endoscopy could be avoided and routine MDCT alone performed.

Double aortic arch presenting as neonatal respiratory failure in the delivery room

Respiratory symptoms are prevalent in vascular ring anomalies, including double aortic arch, which is considered the most common type of vascular ring. However, respiratory failure owing to critical airway obstruction in the neonatal period is rare with few reported cases in the literature. We report a case of a newborn patient who required emergent intubation within the first few hours of life and was later discovered to have a double aortic arch.

Follow-Up of Persistent Tracheal Stenosis After Surgery for a Double Aortic Arch

Persistent respiratory symptoms often occur after surgical repair of double aortic arch (DAA). Most often, symptoms are relatively mild and tend to be self-limited and improve with growth. Multidetector computed tomography (MDCT) imaging can be used to obtain needed anatomic information regarding the potential for extrinsic airway compression and is minimally invasive, safe, and readily available after surgery. We herein report the cases of two patients with persistent airway symptoms after surgical therapy for a double aortic arch. One of the patients eventually required aortopexy in order to achieve complete relief from recurrent symptoms of airway compression. In the other case, wheezing persisted following surgical division of the vascular ring, but it resolved over time without further intervention. In both cases, serial follow-up imaging with computed tomography scans was informative and helped guide management decisions.

Multidetector computed tomography of pediatric large airway diseases: state-of-the-art

Advances in multidetector computed tomography (MDCT) technology have given rise to improvements in the noninvasive and comprehensive assessment of the large airways in pediatric patients. Superb two-dimensional and three-dimensional reconstruction MDCT images have revolutionized the display of large airways and enhanced the ability to diagnose large airway diseases in children. The 320-MDCT scanner, which provides combined detailed anatomic and dynamic functional information assessment of the large airways, is promising for the assessment of dynamic large airway disease such as tracheobronchomalacia. This article discusses imaging techniques and clinical applications of MDCT for assessing large airway diseases in pediatric patients.

Airway management in an infant with double aortic arch

A 2-month old male was admitted due to repeated cyanotic attacks. He had suffered from stridor and retractive breathing since birth. Double aortic arch was diagnosed and the vascular ring formed by the double aortic arch was compressing the trachea. Multirow detector computed tomography showed that he had a right-dominant double aortic arch with left ductus arteriosus and an aberrant left subclavian artery, and that the narrowest part of the trachea, where the diameter was 2.0 mm, was located 9.0 mm above the carina. Airway management in patients with extreme narrowing of the trachea is challenging for anesthesiologists. He was scheduled for ligation and division of the left aortic arch and ductus arteriosus. In the operating theater, anesthesia was slowly induced with sevoflurane (0-4%) in oxygen. After mask ventilation was confirmed to be adequate, a 4.0 mm internal diameter endotracheal tube (ETT) was inserted and advanced smoothly beyond the tracheal stenosis. The tip of the ETT was placed just above the carina using a fiber optic bronchoscope (fiberscope) that was passed through the ETT. Since mechanical ventilation was adequate, vecuronium was administered. Surgery was conducted in the right lateral position and using a left thoracotomy approach. Anesthesia was maintained with sevoflurane (2-3%). After positioning, right one-lung ventilation was performed unexpectedly. However, anesthetic management was achieved without difficult ventilation during surgery. The tip of the ETT was pulled past the stenotic part before transfer to the intensive care unit (ICU). A patent trachea during spontaneous breathing under CPAP (5 and 2 cmH(2)O) was confirmed with a bronchofiberscope in the ICU. After weaning from mechanical ventilation, he had the persistence of mild stridor despite improvement of respiratory symptoms.

Tracheobronchomalacia in infants and children: multidetector CT evaluation

Tracheobronchomalacia (TBM) is the most common congenital central airway anomaly, but it frequently goes unrecognized or is misdiagnosed as other respiratory conditions such as asthma. Recent advances in multidetector computed tomography (CT) have enhanced the ability to noninvasively diagnose TBM with the potential to reduce the morbidity and mortality associated with this condition. Precise indications are evolving but may include symptomatic pediatric patients with known risk factors for TBM and patients with otherwise unexplained impaired exercise tolerance; recurrent lower airways infection; and therapy-resistant, irreversible, and/or atypical asthma. With multidetector CT, radiologists can now perform objective and quantitative assessment of TBM with accuracy similar to that of bronchoscopy, the reference standard for diagnosing this condition. Multidetector CT enables a comprehensive evaluation of pediatric patients suspected of having TBM by facilitating accurate diagnosis, determining the extent and degree of disease, identifying predisposing conditions, and providing objective pre- and postoperative assessments. In this article, the authors present a step-by-step primer of multidetector CT imaging for evaluating infants and children with suspected TBM, including clinical indications, patient preparation, multidetector CT techniques and protocols, two- and three-dimensional processing of multidetector CT data, and image interpretation. The major aim of this article is to facilitate the reader's ability to successfully employ multidetector CT imaging protocols for evaluation of TBM in infants and children in daily clinical practice.

MDCT assessment of tracheomalacia in symptomatic infants with mediastinal aortic vascular anomalies: preliminary technical experience

BACKGROUND

Mediastinal aortic vascular anomalies are relatively common causes of extrinsic central airway narrowing in infants with respiratory symptoms. Surgical correction of mediastinal aortic vascular anomalies alone might not adequately treat airway symptoms if extrinsic narrowing is accompanied by intrinsic tracheomalacia (TM), a condition that escapes detection on routine end-inspiratory imaging. Paired inspiratory-expiratory multidetector CT (MDCT) has the potential to facilitate early diagnosis and timely management of TM in symptomatic infants with mediastinal aortic vascular anomalies.

OBJECTIVE

To assess the technical feasibility of paired inspiratory-expiratory MDCT for evaluating TM among symptomatic infants with mediastinal aortic vascular anomalies.

MATERIALS AND METHODS

The study group consisted of five consecutive symptomatic infants (four male, one female; mean age 4.1 months, age range 2 weeks to 6 months) with mediastinal aortic vascular anomalies who were referred for paired inspiratory-expiratory MDCT during a 22-month period. CT angiography was concurrently performed during the end-inspiration phase of the study. Two pediatric radiologists in consensus reviewed all CT images in a randomized and blinded fashion. The end-inspiration and end-expiration CT images were reviewed for the presence and severity of tracheal narrowing. TM was defined as > or =50% reduction in tracheal cross-sectional luminal area between end-inspiration and end-expiration. The presence of TM was compared to the bronchoscopy results when available (n = 4).

RESULTS

Paired inspiratory-expiratory MDCT was technically successful in all five patients. Mediastinal aortic vascular anomalies included a right aortic arch with an aberrant left subclavian artery (n = 2), innominate artery compression (n = 2), and a left aortic arch with an aberrant right subclavian artery (n = 1). Three (60%) of the five patients demonstrated focal TM at the level of mediastinal aortic vascular anomalies. The CT results were concordant with the results of bronchoscopy in all patients who underwent bronchoscopy (n = 4).

CONCLUSION

Paired inspiratory-expiratory MDCT is technically feasible for evaluating TM in symptomatic infants with mediastinal aortic vascular anomalies and has the potential to facilitate prompt diagnosis and treatment.