## 4 Discussion and Conclusions
An interesting  
Figure 8: Example of aneurysm segmentation provided by: (**a**) EVAR-eaSE software using an automatic seeded region grow algorithm starting from inside; (**b**) 3 Mensio requiring manual selection of markers on the external sac profile. Figure 7: Example of consecutive steps for aneurysm volumes computation when using 3 Mensio, based on manual selection of fiduciary markers along the vessel profile in two different planar projections: selection for abdominal aortic aneurysm (AAA) Total volume (**a**), AAA thrombus and lumen volumes (**b**,**c**). Calculation of endoluminal Free Volume (FV) available for Sac Embolization (SE) (orange area in (**d**)) is not directly provided by the software but has to be performed offline. finding was also that the volumetric accuracy provided by EVAR-eaSE software does not depend on the CTA scan parameters. The mean difference we found between the real and the segmented volume for phantom 2 was comparable to percentage difference (2.2%) previously reported in a similar accuracy evaluation performed for AngioSuite software [17], considered the most accurate method to calculate aneurysm volume among various angiography-based and tomographic-based methods [16]. The slight volume underestimation obtained with EVAR-eaSE may depend on the phantom plastic material and the surrounding air that reduce the efficiency of the EVAR-eaSE contrast-enhanced algorithm, tuned for lumen vessel segmentation. _Study Limitations:_  
At present, the functionalities of EVAR-eaSE software are not fully optimized. In the current version, the AAA total volume segmentation may require subsequent interactions by the user to change and set the optimal parameters to improve the segmentation result. Future developments will be addressed to optimize this step, as well as to implement the calculation of additional parameters, such as the packing density, as already provided by neurovascular software tools [16]. The obtained preliminary results of good accuracy require to be confirmed on a wider range of volumes and phantom shapes more adherent to the real in vivo anatomy. In the present study, we do not compare the EVAR-eaSE tool with 3 Mensio in term of accuracy, but we only verify if there is a similar trend between the volumetric computations obtained by the two software tools (having already available 3 Mensio data for the retrospective database of AAA cases treated with EVAR coil embolization). As next step, it would be interesting to evaluate and compare the accuracy between the new EVAR-eaSE tool and 3 Mensio by performing the accuracy tests on phantoms also for 3 Mensio. The current study also lacks of a comparison of EVAR-eaSE results when the tool is used by different operators on the same patient scan. Future studies could be addressed to evaluate any possible inter-operator differences in terms of volumetric outputs and execution time. Moreover, a feasibility study should be planned and conducted on EVAR-eaSE implementation and usability before promoting it for general use in the clinical practice. In summary, the new EVAR-eaSE software provides an easy and accurate tool for calculating AAA volumes from patient-specific CTA scans, and for estimating the optimal number of coils to be implanted during SE to avoid long-term recurrences. The introduction of this software in routine preoperative planning may facilitate the practical use and acceptance of SE procedure during EVAR. The following are available online at [[http://www.mdpi.com/2076-3417/10/18/6252/s1](http://www.mdpi.com/2076-3417/10/18/6252/s1)]([http://www.mdpi.com/2076-3417/10/18/6252/s1](http://www.mdpi.com/2076-3417/10/18/6252/s1)), Video S1: EVAR-eaSE Demo application. Conceptualization, L.C., S.L. and E.M.; methodology, L.C., S.L., C.M. ; software, S.L. ; data analysis and curation, L.C., B.B. ; writing--original draft preparation, L.C. and S.L. ; writing--review and editing, L.C., S.L. and E.M.; supervision, M.G. and E.M. All authors have read and agreed to the published version of the manuscript.