Stabilization of the Abdominal Aorta During the Cardiac Cycle with the Sac-Anchoring Nellix Device

Itoga, Nathan K.; Suh, Ga-Young; Cheng, Christopher P.

doi:10.1016/j.avsg.2018.02.039

Cited by 5 publications

(5 citation statements)

References 11 publications

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“…This finding is in contrast with conventional transrenal or infrarenal endografts that do not seem to alter renal artery motion. 18 The renal branch angle change owing to pulsatile motion reported in the case series by Itoga et al 20 was similar to the Nellix-to-chimney angle change reported in the present study, indicating that the mechanical damping of renal artery movement is similar with EVAS and chEVAS, whereas a damping of SMA movement was observed with chEVAS only. In chE-VAS, this damping effect could contribute to a more stable configuration and therewith lead to less stent migration.…”

Section: Discussionsupporting

confidence: 89%

“…In the present study, albeit still small, we observed fairly greater magnitudes of motion (#1.7 mm). This finding might be explained by the transrenal positioning of the stents and thus the greater proximity of the stents to the heart compared to the infrarenal fixated stents in the study by Itoga et al 20 Interestingly, because the Nellix stents were fixated infrarenally, this study further found a mechanical damping effect of the Nellix device on renal artery movement. This finding is in contrast with conventional transrenal or infrarenal endografts that do not seem to alter renal artery motion.…”

Section: Discussionmentioning

confidence: 54%

“…18,19 Similarly, fenestrated endografts have been shown to limit side branch motion, which may be important with regard to branch vessel patency. 18 It was previously shown by Itoga et al 20 that, after EVAS, the Nellix stents undergo minimal pulsatile motion between mid-diastole and peak systole (magnitude of movement of <0.5 mm). In the present study, albeit still small, we observed fairly greater magnitudes of motion (#1.7 mm).…”

Section: Discussionmentioning

confidence: 94%

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Electrocardiography-gated computed tomography angiography analysis of cardiac pulsatility-induced motion and deformation after endovascular aneurysm sealing with chimney grafts

Koenrades

Donselaar

Erp

et al. 2020

Journal of Vascular Surgery

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Objective: To evaluate the proximal stability of the chimney endovascular aneurysm sealing configuration (chEVAS) during the cardiac cycle by investigating the cardiac pulsatility-induced movement and deformation. Methods:We retrospectively analyzed postoperative electrocardiogram-gated computed tomography angiography scans of 11 chEVAS cases (9 primary chEVAS plus 2 chEVAS-in-chEVAS). ChEVAS procedures were conducted between September 2013 and June 2016. Motion and deformation of the EVAS stents, the chimney grafts, and the stented branch vessels were evaluated during the cardiac cycle using an established combination of image registration and segmentation techniques.Results: Electrocardiogram-gated computed tomography angiography scans of 11 chEVAS configurations including 22 EVAS stents and 20 chimney grafts were analyzed. The three-dimensional displacement was at most 1.7 mm for both the EVAS stents and the chimney grafts. The maximum change in distance between components was no more than 0.4 mm and did not differ between EVAS-to-EVAS stent and EVAS stent-to-chimney stent (0.2 6 0.1 mm vs 0.2 6 0.1 mm; P ¼ .823). The mean change in chimney deflection angle was 1.2 6 0.7 ; the maximum change was greatest for the superior mesenteric artery (SMA) (2.6 ). The EVAS stent-to-chimney angles for the left renal artery, right renal artery, and SMA varied on average by 0.7 6 0.3 (range, 0.4 -1.3 ), 1.0 6 0.3 (range, 0.5 -1.7 ), and 0.8 6 0.4 (range, 0.3 -1.3 ), respectively, during the cardiac cycle. The end-stent angles for the left renal artery, right renal artery, and SMA varied on average by 1.7 6 0.9 (range, 0.5 -3.3 ), 1.9 6 0.8 (range, 0.7 -3.3 ), and 1.3 6 0.4 (range, 0.7 -1.6 ), respectively, during the cardiac cycle. Overall, the end-stent angles varied on average by 1.7 6 0.8 (range, 0.5 -3.3 ). Conclusions:The chEVAS configuration proved to be stable during the cardiac cycle, as demonstrated by minimal cyclical changes in distance between device components and angulation between the EVAS stents and the chimney grafts. The limited deflection angles of the chimney grafts decrease the risk of bending fatigue, but the more apparent change in end-stent angle distal to the chimney graft may raise concerns regarding late branch occlusion or stenosis.

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Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 54%

Section: Discussionmentioning

confidence: 94%

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Electrocardiography-gated computed tomography angiography analysis of cardiac pulsatility-induced motion and deformation after endovascular aneurysm sealing with chimney grafts

Koenrades

Donselaar

Erp

et al. 2020

Journal of Vascular Surgery

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“…9,10 Because of the relative infrequency of cardiac-gated 3-dimensional (3D) imaging of the abdomen and the relatively recent arrival of EVAS, very little is known about the cardiac pulsatility-induced deformation of the abdominal aorta and its branches after EVAS. 11 Even less is known about how EVAS alters renal artery geometry and motion, which has been shown to be affected by EVAR. 12 In vivo motion, whether from cardiac pulsatility or respiration sources, could have potential relevance to aortic stent-graft design, branch vessel device design, therapeutic strategy, surveillance regimens, and failure mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Cardiac Pulsatility– and Respiratory-Induced Deformations of the Renal Arteries and Snorkel Stents After Snorkel Endovascular Aneurysm Sealing

et al. 2019

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Purpose: To quantify deformations of renal arteries and snorkel stents after snorkel endovascular aneurysm sealing (Sn-EVAS) resulting from cardiac pulsatility and respiration and compare these deformations to patients with untreated abdominal aortic aneurysms (AAA) and snorkel endovascular aneurysm repair (Sn-EVAR). Materials and Methods: Ten Sn-EVAS patients (mean age 75±6 years; 8 men) were scanned with cardiac-gated, respiration-resolved computed tomography angiography. From 3-dimensional geometric models, changes in renal artery and stent angulation and curvature due to cardiac pulsatility and respiration were quantified. Respiration-induced motions were compared with those of 16 previously reported untreated AAA patients and 11 Sn-EVAR patients. Results: Renal artery bending at the stent end was greater for respiratory vs cardiac influences (6°±7° vs −1°±2°, p<0.025). Respiration caused a 3-fold greater deformation on the left renal artery as compared with the right side. Maximum curvature change was higher for respiratory vs cardiac influences (0.49±0.29 vs 0.24±0.17 cm−1, p<0.025), and snorkel renal stents experienced similar maximum curvature change due to cardiac pulsatility and respiration (0.14±0.10 vs 0.19±0.09 cm−1, p=0.142). When comparing the 3 patient cohorts for respiratory-induced deformation, there was significant renal branch angulation in untreated AAAs, but not in Sn-EVAR or Sn-EVAS, and there was significant bending at the stent end in Sn-EVAR and Sn-EVAS. Maximum curvature change due to respiration was ~10-fold greater in Sn-EVAR and Sn-EVAS compared to untreated AAAs. Conclusion: The findings suggest that cardiac and respiratory influences may challenge the mechanical durability of snorkel stents of Sn-EVAS; similarly, however, respiration may be the primary culprit for tissue irritation, increasing the risk for stent-end thrombosis, especially in the left renal artery. The bending stiffness of snorkel stents in both the Sn-EVAR and Sn-EVAS cohorts damped renal branch angulation while it intensified bending of the artery distal to the snorkel stent. Understanding these device-to-artery interactions is critical as they may affect mechanical durability of branch stents and quality and durability of treatment.

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“…Although curvature is a relatively novel parameter for aorto-iliac geometry quantification, curvature has been investigated as a predictor for complications after EVAR before. 18,19,[27][28][29][30][31] However, to fully describe the geometrics of a 3D CLL, torsion should be considered as well. Torsion describes the extent to which the induced curvature involves the third dimension.…”

Section: Discussionmentioning

confidence: 99%

Geometrical Changes of the Aorta as Predictors for Thromboembolic Events After EVAR With the Anaconda Stent-Graft

et al. 2022

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Purpose: Thromboembolic events (TE), including limb graft occlusion (LGO) and distal limb embolization (DLE), are common complications after endovascular aneurysm repair (EVAR). The aim of this study was to find predictors for TE in patients treated with the Anaconda stent-graft for infrarenal aneurysms. Materials and Methods: Geometrical and anatomical variables were retrospectively analyzed in a consecutive Anaconda cohort. Pre- and postoperative CT scans were used to derive geometrical parameters length, curvature, torsion, and tortuosity index (TI) from the center lumen lines (CLLs). Limb characteristics, pre-to-post EVAR and mid-term-follow-up changes in the parameters were evaluated for their predictive value for TE. Results: Eighty-four patients (mean age 74±8.3 years, 74 men) were enrolled. The risk of TE was lowered with pre-to-post implant decreasing TI (steps of 0.05: OR: 1.30, 95% CI: 1.01-1.66, p=0.04), pre-to-post implant decreasing mean curvature (OR: 1.08, 95% CI: 1.01-1.16, p=0.03), and a larger degree of circumferential common iliac artery (CIA) calcification (OR: 0.98, 95% CI: 0.97-1.00, p=0.03). The only LGO predictor was the caudal relocation of maximal curvature after EVAR (OR: 1.01, 95% CI: 1.00-1.01, p=0.04). Preventors of DLE were CIA diameter (OR: 0.87, 95% CI: 0.76-0.99, p=0.04), circumferential CIA calcification (OR: 0.97, 95% CI: 0.95-1.00, p=0.03), mean and maximal curvature of the preoperative aortoiliac trajectory (OR: 0.86, 95% CI: 0.79-0.94, p<0.01 and OR: 0.97, 95% CI: 0.95-1.00, p=0.03, respectively) and pre-to-postoperative decrease in mean curvature (OR: 1.11, 95% CI: 1.02-1.21, p=0.02). Midterm TE predictors were length (OR: 0.95, 95% CI: 0.89-1.01, p=0.08) and torsion maximum location (OR: 1.01, 95% CI: 0.99-1.01, p=0.10). Conclusion: The present study confirms that treatment of infrarenal AAA with an Anaconda stent-graft is related to a relatively high TE rate which decreases with a pre-to-postoperative reduction in curvature and TI, and a larger degree of circumferential CIA calcification. In other words, more aortoiliac straightening and more circumferential CIA calcification may prevent TE development after EVAR with this stent-graft.

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Stabilization of the Abdominal Aorta During the Cardiac Cycle with the Sac-Anchoring Nellix Device

Cited by 5 publications

References 11 publications

Electrocardiography-gated computed tomography angiography analysis of cardiac pulsatility-induced motion and deformation after endovascular aneurysm sealing with chimney grafts

Electrocardiography-gated computed tomography angiography analysis of cardiac pulsatility-induced motion and deformation after endovascular aneurysm sealing with chimney grafts

Cardiac Pulsatility– and Respiratory-Induced Deformations of the Renal Arteries and Snorkel Stents After Snorkel Endovascular Aneurysm Sealing

Geometrical Changes of the Aorta as Predictors for Thromboembolic Events After EVAR With the Anaconda Stent-Graft

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