Pulmonary function tests leading to the diagnosis of vascular ring in an infant

Long term respiratory morbidity in patients with vascular rings: a review

Abnormalities in position and/or branching of the aortic arch can lead to vascular rings that may cause narrowing of the tracheal lumen due to external compression, or constriction of the oesophagus, causing symptoms that vary in relation to the anatomical vascular pattern and the relationship between these structures. Respiratory morbidity related to external airways compression is a major concern in children affected by vascular rings. Clinical presentation depends on the severity of the tracheal lumen reduction and the presence of associated tracheomalacia. Recurrent respiratory infections, wheezing, atelectasis, and hyperinflation are mostly reported. As they are nonspecific and therefore difficult to recognize, attention should be given to all children with history of respiratory distress, extubation failure, noisy breathing, and recurrent respiratory infections. Early diagnosis and referral to specialized centres can prevent the long-term complications and improve the respiratory outcomes of these patients.

The Role of Lung Function Testing in Newborn Infants With Congenital Thoracic Arterial Anomalies

Introduction: Congenital thoracic arterial anomalies (CTAAs), such as complete or incomplete vascular rings, pulmonary artery sling, and innominate artery compression syndrome, may cause severe tracheomalacia and upper airway obstruction. An obstructive ventilatory pattern at lung function testing (LFT) has been suggested in the presence of CTAA. The severity of obstruction may be evaluated by LFT. Little is known about the use of LFT in newborn infants with CTAA. The aim of our study is to evaluate the role of LFT in CTAA diagnosis. Methods: This is a retrospective study, conducted between February 2016 and July 2020. All CTAA cases for whom LFT was performed preoperatively were considered for inclusion. Tidal volume (Vt), respiratory rate, and the ratio of time to reach the peak tidal expiratory flow over total expiratory time (tPTEF/tE) were assessed and compared to existing normative data. Demographics and CTAA characteristics were also collected. Results: Thirty cases were included. All infants with CTAA showed a significantly reduced Vt and tPTEF/tE, compared to existing normative data suggesting an obstructive pattern. No significant differences were found for LFT between cases with a tracheal obstruction <50% compared to those with tracheal obstruction ≥50%, or between cases with and without symptoms. Sixteen infants (53.3%) had respiratory symptoms related to CTAA. Of these, only two cases had also dysphagia. Conclusion: LFT values were significantly reduced in cases with CTAA before surgery. LFT represents a potential feasible and non-invasive useful tool to guide diagnosis in the suspect of CTAA.

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.

Early lung function testing in infants with aortic arch anomalies identifies patients at risk for airway obstruction

Background

Aortic arch anomalies (AAA) are rare cardio-vascular anomalies. Right-sided and double-sided aortic arch anomalies (RAAA, DAAA) are distinguished, both may cause airway obstructions. We studied the degree of airway obstruction in infants with AAA by neonatal lung function testing (LFT).

Patients and Methods

17 patients (10 RAAA and 7 DAAA) with prenatal diagnosis of AAA were investigated. The median (range) post conception age at LFT was 40.3 (36.6–44.1) weeks, median body weight 3400 (2320–4665) g. Measurements included tidal breathing flow-volume loops (TBFVL), airway resistance (R_aw) by bodyplethysmography and the maximal expiratory flow at functional residual capacity (V′_maxFRC) by rapid thoracic-abdominal compression (RTC) technique. V′_maxFRC was also expressed in Z-scores, based on published gender-, age and height-specific reference values.

Results

Abnormal lung function tests were seen in both RAAA and DAAA infants. Compared to RAAA infants, infants with DAAA had significantly more expiratory flow limitations in the TBFVL, (86% vs. 30%, p<0.05) and a significantly increased R_aw (p = 0.015). Despite a significant correlation between R_aw and the Z-score of V′_maxFRC (r = 0.740, p<0.001), there were no statistically significant differences in V′_maxFRC and it's Z-scores between RAAA and DAAA infants. 4 (24%) infants (2 RAAA, 2 DAAA) were near or below the 10^th percentile of V′_maxFRC, indicating a high risk for airway obstruction.

Conclusion

Both, infants with RAAA and DAAA, are at risk for airway obstruction and early LFT helps to identify and to monitor these infants. This may support the decision for therapeutic interventions before clinical symptoms arise.

Endoscopy for the initial suspicion of vascular rings in tracheoesophageal compressions: correlation with surgical findings

Vascular rings (VR) may produce extrinsic compression of trachea and/or esophagus. Diagnosis relies on nonspecific clinical data from resulting compression and image studies, mainly angiography, computed tomography, and cardiovascular MRI. Because of their low incidence, diagnosis is often missed. The role of bronchoscopy and esophagoscopy is controversial, but these procedures might establish for the first time the diagnostic suspicion of VR. This communication was aimed to determine to what extent endoscopic manifestations lead the clinician to suspect the presence of a VR and, moreover, to define their correlation with surgical findings.

METHODS

Children with endoscopic diagnosis of VR submitted to surgery were retrospectively analyzed.

RESULTS

Twenty patients fulfilled inclusion criteria. They were submitted to 19 bronchoscopies and 16 esophagoscopies, and in 60% cases they raised the first suspicion of VR. Diagnostic agreement of the type of VR between endoscopy and surgery was 85%. Bronchoscopy diagnosed 12 VR, and in 10 cases predicted the specific type of VR. Additional relevant findings were detected in nine patients (47.4%). Esophagoscopy diagnosed VR in 14 patients, predicted the specific type in 78.6% and detected all aberrant right subclavian artery cases.

CONCLUSIONS

Initial suspicion of VR was raised by bronchoscopic and/or esophagoscopic findings in 60% cases. Endoscopy proved to be a valuable tool to anticipate the type of malformation and to disclose associated abnormalities.