1. Vranicar M, Douglas W, Gregory W, Di Sessa TG: The Use of Stereolithographic Hand Held Models for Evaluation of Aortic Arch Anomalies. The Fourth World Congress of Pediatric Cardiology and Cardiac Surgery, Buenos Aires, Argentina Sept , 2005

2. Purpose: Imaging of coarctation of the aorta has been accomplished using conventional biplane modalities as well as three-dimensional (3D) video displays. The aim of this study was to evaluate the use of stereolithography to create 3D models to assess this anomaly.
Methods: Seven patients had high-resolution CT scans to evaluate a coarctation ( X native X recoarctation). Ages were 67 to 348 mos, weights were 23 to 84 kg, and 4 were male. Digital dicom data from each scan were converted by a commercially available software package into a 3D digital image. The area of interest was selected and the image was exported to a 3D stereolighographic printer to create a 3D model. The models were evaluated and the results were compared to CT scan reports and catheterization and surgical findings.
Results: All models accurately displayed the pathology investigated. These models identified the site of coarctation, relationship to brachiocephalic vessels, and aortic hypoplasia. Angiographic images, CT images and stereolithographic model reconstructions were concordant 3 Patients. In one subject the model showed severe arch tortuosity not appreciated on CT scan that prohibited stent placement. In addition, two CT scans failed to identify a definitive coarctation. However, the models clearly showed the coarctation. One model allowed for a more definitive diagnosis than the CT scan.
Conclusion: Stereolithography can create realistic 3D models that accurately display aortic pathology and add important additional information, which may have implications regarding surgical and transcatheter intervention. The models may also be useful teaching tools for parents, students, and residents.

3. Angiographic Findings/Gradient
Age (mths)
Weight (kg)
CT Diagnosis
Model Diagnosis
Angiographic Findings/Gradient
OR Findings 1
0.6
3.3
Double Arch, atretic left arch 2
6.2
6.0
Pulmonary sling 3 59
14.5
Double Arch, cannot exclude right arch with aberrent left subclavian 4
1.5
8.2
Absence of a normal situated aortic arch with severe coarctation
Tortuous aorta with severe coarctation
Coarctation with very unusual tortuous transverse aorta 5 67
22.7
Consistent with coarct, though pseudocoarct should be considered
Discrete coarctation
24 mmHg
Coarctation 6
171
63.2
Marked post-ductal narrowing, consistent with coarctation
Severe coarctation
58 mmHg 7
321
84.5
Coarctation distal
to left subclavian
Coarctation due to kinking distal to left subclavian artery
11 mmHg 8
125
28.2
Coarctation with kinking proximal and distal to left subclavian artery
Coarctation with tortuous
aorta and narrow
transverse arch
Coarctation with
tortuous aorta 9
184
79.5
Mild irregularity and narrowing, no definitive coarctation
Long segment juxtaductal coarctation
16 mmHg 10
75.5
Stented Coarctation
8 mmHg 11
216
139
Subtle narrowing, however aorta widely patent
Re-coarct due to hypoplastic transverse arch
Pending 12
358
70.9
Stented coarctation, no areas of stenosis
Stented distal aorta, residual coarctation near innominate artery
15 mmHg

4. A B
LAA
RAA
LAA
RAA
Figure 1. Model from a 4 year-old (subject 3) with a vascular ring due to a double aortic arch. The view from the front (A) shows a dominant right aortic arch (RAA) and a smaller left aortic arch (LAA) with 2 vessels arising off of each arch. The view from above (B) shows how the two arches form a ring through which the trachea and esophagus pass.

5. LSCA TA PA
Figure 2. Anterior view of a model from a 10 year-old (subject 8) with recoarctation of the aorta. The transverse arch (TA) is tortuous and there is a discrete coarctation (arrow) just distal to the left subclavian artery (LSCA). PA = pulmonary artery.

6. A B TA TA PA PA
Figure 3. Model from a 1 month-old (subject 4) with a native coarctation. The view from the front (A) shows an unusual tortuous transverse aorta (TA). A left anterior oblique view (B) shows the severe discrete coarctation proximal to the origin of the left subclavian artery. PA = pulmonary artery.

7. A B Ascending aorta LPA LPA MPA
Figure 4. Model from a 6 month old with a pulmonary sling (subject 2). The view from the front (A) shows the main pulmonary artery (MPA), but the origin of the left pulmonary artery (LPA) is not well seen. Viewed from above (B) the LPA can be seen originating from the right pulmonary artery and is compressed where it passes behind the trachea.