“Redo” 2D–3D Fusion Technique during Endovascular Redo Aortic Repair

Purpose: The present study aims to describe a new 2D–3D fusion registration method in the case of endovascular redo aortic repair and compare the accuracy of the registration using the previously implanted devices vs. bones as landmarks. Materials and Methods: This single-center study prospectively analyzed all the patients that underwent elective endovascular re-interventions using the Redo Fusion technique between January 2016 and December 2021 at the Vascular Surgery Unit of the Fondazione Policlinico Universitario A. Gemelli (FPUG)—IRCCS in Rome, Italy. The fusion overlay was performed twice, first using bone landmarks (bone fusion) and the second using radiopaque markers of a previous endovascular device (redo fusion). The pre-operative 3D model was fused with live fluoroscopy to create a roadmap. Longitudinal distances between the inferior margin of the target vessel in live fluoroscopy and the inferior margin of the target vessel in bone fusion and redo fusion were measured. Results: This single-center study prospectively analyzed 20 patients. There were 15 men and five women, with a median age of 69.7 (IQR 42) years. The median distance between the inferior margin of the target vessel ostium in digital subtraction angiography and the inferior margin of the target vessel ostium in bone fusion and redo fusion was 5.35 mm and 1.35 mm, respectively (p ≤ 0.0001). Conclusions: The redo fusion technique is accurate and allows the optimization of X-ray working views, supporting the endovascular navigation and vessel catheterization in case of endovascular redo aortic repair

Endovascular aneurysm repair: prevention and treatment of complications

The introduction of endovascular aneurysm repair (EVAR) procedures has greatly influenced the treatment of abdominal aortic aneurysms (AAAs). At first, EVAR was introduced as an alternative treatment for patients that could not receive an open surgical AAA repair procedure. Nowadays, EVAR is preferred because of the lower 30-day mortality rates compared to open surgical repairs. However, the durability of EVAR is a major problem, EVAR is associated with graft-related complications and the percentage of reinterventions can be as high as 20%. Because more complex endovascular procedures are being performed, the number of early and late complications may increase. The goal of this research can be divided into two parts. The first was to investigate how new imaging techniques can help to prevent complications during and after treatment of obstructive and aneurysmatic aortoiliac diseases. This thesis shows that the use of 3D image fusion during EVAR procedures can lead to a reduction in the amount of contrast agent used and that new prototype software can be used to visualize small changes in apposition and position of the endograft postoperatively.The second part of this thesis was aimed at outcomes after EVAR. It was investigated how EndoAnchors need to be implanted in order to prevent and treat EVAR complications. The thesis furthermore analyses the risks and effects of the location and placement of EndoAnchors and the risks associated with late open conversion after EVAR

Abdominal aortic aneurysm treatment outcomes in the Netherlands

In this thesis, the nationwide trends in abdominal aortic aneurysm treatment outcomes and outcomes of subgroups such as octogenarians following abdominal aortic aneurysm repair are investigated using data from the Dutch Surgical Aneurysm Audit (DSAA). Moreover, the nationwide outcomes of complex EVAR are described, including a volume-outcome association, and new opportunities for feedback and outcome measurement are discussed

Abdominal aortic aneurysm treatment outcomes in the Netherlands

In this thesis, the nationwide trends in abdominal aortic aneurysm treatment outcomes and outcomes of subgroups such as octogenarians following abdominal aortic aneurysm repair are investigated using data from the Dutch Surgical Aneurysm Audit (DSAA). Moreover, the nationwide outcomes of complex EVAR are described, including a volume-outcome association, and new opportunities for feedback and outcome measurement are discussed

An easy-to-use 2D-3D registration process

This report describes the work carried out during the project representing the final part of the Professional Doctorate in Engineering (PDEng) degree pro-gram in Software Technology provided by the Eindhoven University of Technology and Stan Ackermans Institute. The project name is "An Easy-to-use 2D-3D Registration Process". This project consists of the design and development of an easy-to-use inter-face for image registration for the VesselNavigator prototype developed in Philips Healthcare. The report is addressed to a technical audience that has a general knowledge about software design and medical imaging. Readers that are interested in the clinical background and the goals of the project should refer to Chapters 2-5. Details about the software architecture design and implementation are provid-ed in Chapters 6-8. For the result of the project and the software process used readers must address Chapters 9 and 10

Motion Calculations on Stent Grafts in AAA

Endovascular aortic repair (EVAR) is a technique which uses stent grafts to treat aortic aneurysms in patients at risk of aneurysm rupture. Although this technique has been shown to be very successful on the short term, the long term results are less optimistic due to failure of the stent graft. The pulsating blood flow applies stresses and forces to the stent graft, which can cause problems such as breakage, leakage, and migration. Therefore it is of importance to gain more insight into the in vivo motion behavior of these devices. If we know more about the motion patterns in well-behaved stent graft as well as ill-behaving devices, we shall be better able to distinguish between these type of behaviors These insights will enable us to detect stent-related problems and might even be used to predict problems beforehand. Further, these insights will help in designing the next generation stent grafts. Firstly, this work discusses the applicability of ECG-gated CT for measuring the motions of stent grafts in AAA. Secondly, multiple methods to segment the stent graft from these data are discussed. Thirdly, this work proposes a method that uses image registration to apply motion to the segmented stent mode

Strain ultrasound elastography of aneurysm sac content after randomized endoleak embolization with sclerosing and non-sclerosing chitosan-based hydrogels in a preclinical model

Mise en contexte : La réparation endovasculaire des anévrismes de l’aorte abdominale est limitée par le développement des endofuites, qui nécessite un suivi à long terme par imagerie. L’élastographie sonore de déformation a été proposée comme méthode complémentaire pour aider à la détection des endofuites et la caractérisation des propriétés mécaniques des anévrismes. On s’intéresse ici également à la possibilité de suivre l’embolisation des endofuites, qui est indiquée dans certains cas mais dont le succès est variable. Un nouvel agent d’embolisation a été récemment créé en combinant un hydrogel de chitosane radio-opaque (CH) et le sclérosant tetradecyl sulfate de sodium (STS), qui s’appelle CH-STS. Le CH-STS démontre des propriétés mécaniques in vitro favorables, mais son comportement in vivo et son effet sur l’évolution du sac par rapport à un agent non-sclérosant pourraient être mieux caractérisés. L’objectif de cette étude était la caractérisation des propriétés mécaniques des composantes des endofuites embolisées avec CH-STS et CH avec élastographie sonore de déformation. Méthodologie : Des anévrismes bilatéraux avec endofuites de type I ont été créés au niveau des artères iliaques communes chez neuf chiens. Chez chaque sujet, une endofuite a été embolisée avec CH, et l’autre, avec CH-STS, d’une façon aléatoire et aveugle. Des images d’échographie duplex et des cinéloops pour élastographie sonore de déformation ont été acquis à 1 semaine, 1 mois, 3 mois et (chez 3 sujets) 6 mois post-embolisation. La tomodensitométrie a été faite à 3 mois et (si pertinente) 6 mois post-embolisation. L’histopathologie a été faite au sacrifice. Les études radiologiques et les données d’histopathologie ont été co-enregistrées pour définir trois régions d’intérêt sur les cinéloops : l’agent d’embolisation (au sacrifice), le thrombus intraluminal (au sacrifice) et le sac anévrismal (pendant chaque suivi). L’élastographie sonore de déformation a été faite avec les segmentations par deux observateurs indépendants. La déformation axiale maximale (DAM) a été le critère d’évaluation principal. Les analyses statistiques ont été faites avec des modèles mixtes linéaires généralisés et des coefficients de corrélations intraclasses (ICCs). Résultats : Des endofuites résiduelles ont été trouvées dans 7/9 (77.8%) et 4/9 (44.4%) des anévrismes embolisés avec CH et CH-STS, respectivement. Le CH-STS a eu une DAM 66 % plus basse (p < 0.001) que le CH. Le thrombus a eu une DAM 37% plus basse (p = 0.010) que le CH et 77% plus élevée (p = 0.079) que le CH-STS. Il n’y avait aucune différence entre les thrombi associés avec les deux traitements. Les sacs anévrismaux embolisés avec CH-STS ont eu une DAM 29% plus basse (p < 0.001) que ceux embolisés avec CH. Des endofuites résiduelles ont été associées avec une DAM du sac anévrismal 53% plus élevée (p < 0.001). Le ICC pour la DAM a été de 0.807 entre les deux segmentations. Conclusion : Le CH-STS confère des valeurs de déformations plus basses aux anévrismes embolisés. Les endofuites persistantes sont associées avec des déformations plus élevées du sac anévrismal.Background: Endovascular aneurysm repair (EVAR) is the modality of choice for the treatment of abdominal aortic aneurysms (AAAs). EVAR is limited by the development of endoleaks, which necessitate long-term imaging follow-up. Conventional follow-up modalities suffer from unique limitations. Strain ultrasound elastography (SUE) has been recently proposed as an imaging adjunct to detect endoleaks and to characterize aneurysm mechanical properties. Once detected, certain endoleaks may be treated with embolization; however, success is limited. In this context, the embolic agent CH-STS—containing a chitosan hydrogel and the sclerosant sodium tetradecyl sulphate (STS)—was created. CH-STS demonstrates favorable mechanical properties in vitro; however, its behavior in vivo and impact on sac evolution compared to a non-sclerosing chitosan-based embolic agent (CH) merit further characterization. Purpose: To compare the mechanical properties of the constituents of endoleaks embolized with CH and CH-STS—including the agent, the intraluminal thrombus (ILT), and the overall sac—via SUE. Methods: Bilateral common iliac artery aneurysms with type I endoleaks were created in nine dogs. In each animal, one endoleak was randomly embolized with CH, and the other with CH-STS. Duplex ultrasound (DUS) and radiofrequency cine loops were acquired at 1 week, 1 month, 3 months, and—in 3 subjects—6 months post-embolization. Contrast-enhanced CT was performed at 3 months and—where applicable—6 months post-embolization. Histopathological analysis was performed at time of sacrifice. Radiological studies and histopathological slides were co-registered to identify three regions of interest (ROIs) on the cine loops: embolic agent (at sacrifice), ILT (at sacrifice), and aneurysm sac (at all follow-up times). SUE was performed using segmentations from two independent observers on the cine loops. Maximum axial deformation (MAD) was the main outcome. Statistical analysis was performed using general linear mixed models and intraclass correlation coefficients (ICCs). Results: Residual endoleaks were identified in 7/9 (77.8%) and 4/9 (44.4%) aneurysms embolized with CH and CH-STS, respectively. CH-STS had a 66 % lower MAD (p < 0.001) than CH. The ILT had a 37% lower MAD (p = 0.010) than CH and a 77% greater MAD (p = 0.079; trending towards significance) than CH-STS. There was no difference in the ILT between treatment groups. Aneurysm sacs embolized with CH-STS had a 29% lower MAD (p < 0.001) than those with CH. Residual endoleak increased MAD of the aneurysm sac by 53% (p < 0.001), regardless of the agent used. The ICC for MAD was 0.807 between readers’ segmentations. Conclusion: CH-STS confers lower strain values to embolized aneurysms. Persistent endoleaks result are associated with increased sac strain, which may be useful for clinical follow-up