Blood flow characteristics after aortic valve neocuspidization in paediatric patients: a comparison with the Ross procedure.

AIMS: The aortic valve (AV) neocuspidization (Ozaki procedure) is a novel surgical technique for AV disease that preserves the natural motion and cardiodynamics of the aortic root. In this study, we sought to evaluate, by 4D-flow magnetic resonance imaging, the aortic blood flow characteristics after AV neocuspidization in paediatric patients. METHODS AND RESULTS: Aortic root and ascending aorta haemodynamics were evaluated in a population of patients treated with the Ozaki procedure; results were compared with those of a group of patients operated with the Ross technique. Cardiovascular magnetic resonance studies were performed at 1.5 T using a 4D flow-sensitive sequence acquired with retrospective electrocardiogram-gating and respiratory navigator. Post-processing of 4D-flow analysis was performed to calculate flow eccentricity and wall shear stress. Twenty children were included in this study, 10 after Ozaki and 10 after Ross procedure. Median age at surgery was 10.7 years (range 3.9-16.5 years). No significant differences were observed in wall shear stress values measured at the level of the proximal ascending aorta between the two groups. The analysis of flow patterns showed no clear association between eccentric flow and the procedure performed. The Ozaki group showed just a slightly increased transvalvular maximum velocity. CONCLUSION: Proximal aorta flow dynamics of children treated with the Ozaki and the Ross procedure are comparable. Similarly to the Ross, Ozaki technique restores a physiological laminar flow pattern in the short-term follow-up, with the advantage of not inducing a bivalvular disease, although further studies are warranted to evaluate its long-term results.

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.

Tracheal trifurcation: new cases and review of the literature.

BACKGROUND: Tracheal trifurcation is an uncommon and often unknown type of anomalous tracheobronchial arborization, characterized by three main bronchi originating at the level of the carina. Diagnosis is important due to its clinical implications. OBJECTIVE: To highlight the anatomical, clinical and diagnostic aspects of tracheal trifurcation by reporting our experience and reviewing the literature. MATERIALS AND METHODS: We retrospectively evaluated pediatric patients referred to our institution from January 2018 to May 2020 with a diagnosis of tracheal trifurcation. All patients underwent chest radiographs, computed tomography (CT) (with/without dynamic airway scanning) and bronchoscopy. Clinical and anatomical data were collected. RESULTS: Three patients with tracheal trifurcation were identified (1 female, median age: 7.6±0.4 months). All had associated anomalies: two had tetralogy of Fallot, one with esophageal atresia/tracheoesophageal fistula and one with an atrioventricular septal defect, and the other had skeletal ciliopathy. Chest radiographs were not diagnostic for tracheal trifurcation. Bronchoscopy could not fully evaluate the trachea and main bronchi in two cases. CT detected tracheal trifurcation in all of the patients and also demonstrated other lung parenchymal and congenital anomalies. Two of the three main bronchi were directed to the right lung in all cases. Ostial stenosis of either the central (two patients) or right upper bronchus (one patient) was present. No signs of tracheobronchomalacia were found. CONCLUSION: Tracheal trifurcation is rare and often associated with additional disorders, such as other tracheobronchial anomalies, cardiovascular defects or esophageal malformations, responsible for clinical manifestations and earlier detection. Bronchoscopy is often used for diagnosis, but is invasive and may be incomplete or inconclusive, while CT allows for a noninvasive and correct diagnosis, while also highlighting additional findings in the thorax.

Dynamic expiratory CT: An effective non-invasive diagnostic exam for fragile children with suspected tracheo-bronchomalacia.

BACKGROUND: Tracheobronchomalacia, defined as variable collapse of the airways, has been recognized as an important cause of respiratory morbidity but still widely underdiagnosed. Bronchoscopy is still considered as the gold standard, but numerous limitations are known, especially for fragile sick children. Moreover, information on parenchymal lung disease cannot be described. There is a real need for a reliable, non-invasive test to help detection of airway and parenchymal malformations in children, specifically when bronchoscopy cannot be performed. METHODS AND RESULTS: 34 paediatric patients underwent cine multidector CT for ongoing respiratory symptoms and were included. All CT images were of good quality and sedation was never needed. Airway disease such as trachea-broncomalacia with/without stenosis was described in 53% with the first being more frequent. Bronchomalacia alone was described in 10 patients and in 4 patients was associated with tracheomalacia. Moreover, CT allowed identification of parenchymal disease in 10 patients. Airways stenosis alone was detected in seven patients. The majority of patients (85%) underwent also bronchoscopy for clinical decision. The agreement between CT and bronchoscopy was explored. The two examinations did not agree only in two cases. CT dynamic showed an excellent sensitivity of 100% (81.47-100 %), a great specificity of 82% (48.22-97.72 %), NPV 100%, and PPV 90% (72-96.9 %). CONCLUSION: Dynamic CT results an effective and highly sensitive diagnostic exam for children with tracheo-bronchomalacia. CT is especially indicated for those small and fragile patients that cannot undergo an invasive investigation. Moreover, CT allows a detailed evaluation both of the airways and the lungs which is useful for the clinical management.