Using computed tomography angiography and computational fluid dynamics to study aortic coarctation in different arch morphologies

Objective

To study the differences in computed tomography angiography (CTA) imaging of gothic arches, crenel arches, and romanesque arches in children with Aortic Coarctation (CoA), and to apply computational fluid dynamics (CFD) to study hemodynamic changes in CoA children with gothic arch aorta.

Methods

The case data and CTA data of children diagnosed with CoA (95 cases) in our hospital were retrospectively collected, and the morphology of the aortic arch in the children was defined as gothic arch (n = 27), crenel arch (n = 25) and romanesque arch (n = 43). The three groups were compared with D1/AOA, D2/AOA, D3/AOA, D4/AOA, D5/AOA, and AAO-DAO angle, TAO-DAO angle, and aortic arch height to width ratio (A/T). Computational fluid dynamics was applied to assess hemodynamic changes in children with gothic arches.

Results

There were no significant differences between D1/AOA and D2/AOA among gothic arch, crenel arch, and romanesque arch (P > 0.05). The differences in D3/AOA, D4/AOA, and D5/AOA among the three groups were statistically significant (P < 0.05), D4/AOA, D5/AOA of the gothic arch group were smaller than the crenel arch group, and the D3/AOA and D5/AOA of the gothic arch group were smaller than the romanesque arch group (P < 0.05). The difference in AAO-DAO angle among the three groups was statistically significant (P < 0.05), and the AAO-DAO angle of gothic arch was smaller than that of romanesque arch and crenel arch group (P < 0.05). There was no significant difference in the TAO-DAO angle between the three groups (P > 0.05). The difference in A/T values among the three groups was statistically significant (P < 0.05), and the A/T values: gothic arch > romanesque arch > crenel arch (P < 0.05). The CFD calculation of children with gothic arch showed that the pressure drop between the distal stenosis and the descending aorta was 58 mmHg, and the flow rate at the isthmus and descending aorta was high and turbulent.

Conclusion

Gothic aortic arch is common in CoA, it may put adverse effects on the development of the aortic isthmus and descending aorta, and its A/T value and AAO-DAO angle are high. CFD could assess hemodynamic changes in CoA.

Debating the embolization of a large aberrant systemic artery for pulmonary sequestration using an Amplatzer duct occluder: a case report and literature review

Here, we report two rare cases of pulmonary sequestration that were fed by large systemic arteries and embolized with a large Amplatzer duct occluder and their 3-year follow-up, and we discuss the efficacy and safety of the embolization of a large aberrant systemic artery to pulmonary sequestration using an Amplatzer duct occluder. A 9-year-old boy complained of chest pain for 1 month, and a 6-year-old boy initially complained of recurrent cough for 3 months. A series of examinations was launched to evaluate any possible malformation or abnormalities in the patients. Chest CT and CTA identified a right lower pulmonary sequestration with infection. After admission, transcatheter device occlusion was planned after essential antibiotic treatment, and postoperative infection prevention and anti-inflammatory treatment were given. In the following 2 years of follow-up, neither of the children had recurrent chest pain, cough or other related symptoms. However, the CT follow-up demonstrated that a residual mass was visible in both patients. The same chest scan section revealed slight reductions in lung lesions from 38.344 cm2 to 37.119 cm2 (3% reduction) and 14.243 cm2 to 13.178 cm2 (7.5% reduction) for each patient. No follow-up data demonstrated the long-term clinical outcomes of the residual lesion. We do not recommend that embolization be performed for large pulmonary sequestration lesions with an aberrant artery larger than 6 mm that is planned to receive a device larger than 10 mm, as their outcomes showed a higher possibility of rebuilding the vascularization network feeding the pulmonary sequestration, indicating a higher risk for long-term complications.

Pulmonary sequestration: What the radiologist should know

Pulmonary sequestration consists of a nonfunctioning mass of lung tissue, either sharing the pleural envelope of the normal lung (intralobar) or with its own pleura (extralobar), lacking normal communication with the tracheobronchial tree and receiving its arterial supply by one or more systemic vessels. It is the second most common congenital lung anomaly according to pediatric case series, but its real prevalence is likely to be underestimated, and imaging plays a key role in the diagnosis and treatment management of the condition and its potential complications. We will give a brief overview of the pathophysiology, clinical presentation and imaging findings of intra- and extralobar pulmonary sequestration, with particular reference to multidetector computed tomography as part of a powerful and streamlined diagnostic approach.