# Volumetric Analysis of Aortic Changes after TEVAR Using Three-Dimensional Virtual Modeling
## 3 Results
\begin{table}
\begin{tabular}{l c} \hline \hline
**TEVAR Data** & \\ \hline Implanted stent graft (total) & 39 \\ Implanted stent graft per TEVAR (mean \(\pm\) SD) & 1.6 \(\pm\) 0.6 \\ \hline Stent graft name & \(n\) (\%) \\ \hline Valiant Captivía\({}^{\text{\textregistered}}\) (Medtronic, Minneapolis, MN, USA) & 27 (69\%) \\ Relay\({}^{\text{\textregistered}}\) (Bolton Medical, Sunrise, FL, USA) & 5 (13\%) \\ TAG\({}^{\text{\textregistered}}\) (Gore Medical, Flagstaff, AZ, USA) & 4 (10\%) \\ Zenith\({}^{\text{\textregistered}}\) (Cook, Bloomington, IN, USA) & 2 (5\%) \\ Custom stent graft (Jotec GmbH, Hechingen, Germany) & 1 (2.5\%) \\ \hline
**TEVAR-related events in the total f/u time** & \(n\) (\%) & **Time after TEVAR (months, mean \(\pm\) SD)** \\ \hline Endoleaks (total) & 12 (50\%) \\ Type Ia & 3 (12.5\%) & 38.3 \(\pm\) 37.7 \\ Type Ib & 3 (12.5\%) & 2.7 \(\pm\) 0.6 \\ Type II & 7 (29.2\%) & 5.1 \(\pm\) 5.4 \\ Type III & 2 (8.3\%) & 49 \(\pm\) 32.5 \\ Type IV &... & \\ Type V & 1 (4.2\%) & 12 \\ \hline Stent graft migration & 6 (25\%) & 26.0 \(\pm\) 16.9 \\ \hline Re-TEVAR (total) & 7 (29.2\%) & \\ \hline
1 & 7 (29.2\%) & 38.3 \(\pm\) 35.0 \\
2 & 3 (12.5\%) & 66.0 \(\pm\) 8.5 \\ \hline Death (total) & 4 (16.7\%) & 42.3 \(\pm\) 29.9 \\ \hline Stent-related & 1 (4.2\%) & 15 \\ Not stent-related & 3 (12.5\%) & 51.3 \(\pm\) 29.1 \\ \hline TEVAR-related complications (total) & 8 (33.3\%) & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: TEVAR-related data, including procedure details and related events in the total follow-up time. Figure 3: CTA follow-up after TEVAR for DTAA showing blood flow outside the stent graft at the proximal landing zone (arrows), with an incomplete seal of the DTAA (type Ia endoleak). The patients were divided into two groups according to the occurrence or absence of TEVAR-related complications, with 16 patients (66%) without reported TEVAR-related complications during the total follow-up time. The results of both the diameter and volume analysis of these two groups at discharge and after 12 months are reported in Table 3.  
An example of the two types of analysis is reported in Figure 4.  
Proximal neck measurements for both the diameter and volume evaluations were not carried out for most patients (81.25%), as the stent graft was positioned right after the origin of the left subclavian artery (landing zone 3), and as such, there was no proximal neck to evaluate. In the diameter evaluation, only the distal landing zone was different between the two groups, with both a net (4.3 \(\pm\) 8.4 mm vs. 0.2 \(\pm\) 3.2 mm, \(p\) = 0.049) and relative increase (10.4 \(\pm\) 18.6% vs. 0.9 \(\pm\) 8.6%, \(p\) = 0.048) in the maximum diameter in patients with TEVAR-related complications compared to substantial stability in the no-complication group. In the volumetric evaluation, except for the proximal landing zone, all other segments of the descending aorta showed significant increases in net volume changes in the TEVAR-related complication group compared to the no-complication group, which showed substantial stability. The DTAA volume increased in the TEVAR-related complication group (13 \(\pm\) 33 mL) and decreased in the no-complication group (\(-\)21 \(\pm\) 48 mL, \(p\) = 0.043). The distal landing zone had a net volume increase in the complication group compared to the no-complication group (17 \(\pm\) 15 mL vs. 3 \(\pm\) 12 mL, \(p\) = 0.022). Both the proximal (6 \(\pm\) 1 mL vs. 2 \(\pm\) 1 mL, \(p\) = 0.001) and distal (22 \(\pm\) 23 mL vs. 2 \(\pm\) 8 mL, \(p\) = 0.030) aortic necks showed a higher increase in volume in the TEVAR-related complication group. When evaluating the global descending thoracic aorta volumes, the patients without complications after 12 months had a mild reduction in their aortic volumes (\(-\)11 \(\pm\) 51 mL), while the patients with complications had a moderate increase in these volumes (55 \(\pm\) 25 mL, \(p\) = 0.001).