Materials and Methods
Our patient initially presented at 7 years of age with shortness of
breath with exertion and noisy breathing at rest. Her exertional
symptoms were progressive, and she experienced prolonged recovery from
upper respiratory infections. Subsequently she was no longer getting
relief from bronchodilators that she had used up to that point. A chest
x-ray revealed a right sided aortic arch. A computerized tomography (CT)
scan demonstrated a double aortic arch with atretic distal left arch
with no Kommerell’s diverticulum. Bronchoscopy was performed which
revealed 40% narrowing at the mid-trachea. Echocardiography examination
provided a normal intra cardiac anatomy. Thoracoscopic division of the
atretic left arch and left ligamentum was performed without incident and
the patient recovered uneventfully.
Two years later the patient continued to have residual symptoms of
shortness of breath with any exercise, including climbing a single
flight of stairs. Her breathing at rest remained noisy, and she became
breathless with talking for extended periods of time. Treatment with
albuterol and fluticasone inhalers did not alleviate symptoms. An
exercise study was performed to better delineate the mechanism of her
symptoms which was read as consistent with mild obstruction. Both during
her exercise testing and when performing spirometry at rest she elicited
normal inspiratory loops, however her expiratory loop was flattened
suggesting dynamic airway obstruction (Figure 1). Bronchoscopy was
repeated which revealed normal vocal cord mobility, but compression at
the lateral rightward aspect of the trachea (Figure 2). A CT scan was
repeated to better delineate her anatomy.
Her case was discussed in our multidisciplinary congenital
cardiac/thoracic conference where her repeat CT scan was reviewed. A
rightward to leftward course of her aorta above the level of the carina
was consistent with the diagnosis of circumflex aorta.
A discussion with the family over the phone where a description of the
relevant anatomy and plan for treatment. Optimal understanding of the
anatomy and its surgical solution was difficult to achieve. A 3D model
of her anatomy using blood and air volumes was made using Materialise®
Mimics and 3-matic software (Leuven Belgium) and was printed on a an
Ultimaker® 3 Extended printer using polylactic acid (PLA) filament.
Figure 3 shows the resultant 3D model, created from her CT scan images.
The post-procedural model was used preoperatively for the second
operation to help describe the symptoms and the complex operation needed
to provide relief of external compression of the trachea (1). This 3D
model made conversation from this point on in the patient’s care clear
in both objectives and planning for outcomes.