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Purpose: The kissing stent (KS) method is low-risk compared with open surgery techniques. It is often used to treat aorto-iliac occlusive disease (AIOD). Deployment of the KS geometry has a high technical success rate. However, stent patency reduces in the first 5 years potentially due to deleterious flow behavior. Potentially harmful hemodynamics due to the KS were investigated in vitro., Methodology: A compliant phantom of the aorto-iliac bifurcation was manufactured. Two surrogate stent-grafts were deployed into the phantom in the KS configuration to investigate effects of the presence of the stents, including the compliance mismatch they cause, on the hemodynamics proximal and distal to the KS. The investigation used pulsatile flow through a flow circuit to simulate abdominal aortic flow. Particle image velocimetry (PIV) was used to quantify the hemodynamics., Results: PIV identified peak proximal and distal velocity in vitro was 0.71 and 1.40m·s -1 , respectively, which were within physiological ranges. Throughout systole, flow appeared normal and undisturbed. A lumen wall collapse in the sagittal plane formed during late systole and continued to early diastole proximal to the aorto-iliac bifurcation, distal to the inlet stent position. The wall collapse led to disturbed flow proximal to the stented region in early diastole producing potential recirculation zones and abnormal flow patterns., Conclusion: The normal systolic flow behavior indicates the KS configuration is unlikely to cause an inflammatory response of the arterial walls. The collapse has not been previously identified and may potentially cause long-term patency reduction. It requires further investigation., Clinical Impact: The role of this article is to provide further insight into the haemodynamic behavior through a stented aorto-iliac artery. The results of this investigation will improve the understanding of the effects that using the kissing stent method may have on a patient and help to identify high risk regions that may require more detailed monitoring. This paper also develops the in vitro modelling techniques that will enable further research that cannot be carried out within patients., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: The cross-limb (CL) technique is a commonly used endovascular treatment for addressing unfavorable anatomical features in patients with abdominal aortic aneurysm (AAA). The configuration of CL stent-graft plays a critical role in determining the postoperative hemodynamic properties and physiological behaviors, which ultimately impact the efficacy and safety of endovascular AAA treatment. This study aims to investigate the relationship between hemodynamics and CL stent-graft configuration from a hemodynamic perspective., Methods: Five distinct geometric models of cross-limb (CL) stent-graft configurations were constructed by optimizing the real clinical computed tomography angiography (CTA) data. These models varied in main body lengths and cross angles and were used to perform numerical simulations to analyze various hemodynamic parameters. Flow pattern, distribution of wall shear stress (WSS)-related parameters, localized normalized helicity (LNH), pressure drop, and the displacement force of all models were examined in this paper., Results: In patient-specific cases, helical flow and WSS increase with the main body. However, it also generated secondary flow in localized areas, leading to increased oscillation in the WSS direction. Notably, increasing the stent graft's main body length or decreasing the cross angle reduced the displacement force exerted on the stent-graft. Reducing the cross angle did not significantly alter the hemodynamic characteristics., Conclusion: In the clinical practice of CL deployment, it is crucial to carefully consider the stent-graft configuration and the patient specific to achieve optimal postoperative outcomes. This study provides valuable insights for guiding stent selection and treatment planning in patients with abdominal aortic aneurysm undergoing CL techniques, from a hemodynamic perspective., (© 2023. The Author(s) under exclusive licence to Biomedical Engineering Society.)

Background: The aim of this study was to report the results of a multicenter experience on the use of adjunctive stents deployed inside abdominal aortic endografts with the purpose to prevent or treat limb occlusion after endovascular aneurysm repair (EVAR)., Methods: Between 2010 and 2018, there were 35 patients with aorto-iliac aneurysm presenting one or more risk factors for endograft limb occlusion (narrow aortic bifurcation and/or stenotic, highly angulated or occluded iliac arteries), who were treated with standard bifurcated stent graft reinforced by the means of a single model of balloon-expandable platinum/iridium bare stent (CP Stent; NuMED, Inc., Hopkinton, NY, USA). Technical success, mortality, limb patency and reintervention rate during follow-up were the main endpoints assessed., Results: Technical success was 100%. No patients died perioperatively and no major complication was registered. During a mean follow-up of 48 months (range 1-87), neither aortic-related death nor secondary intervention was registered. At a mean follow-up imaging of 39.4 months (range 1-81) no endograft limb lost its patency., Conclusions: The use of high-radial force balloon-expandable stents deployed inside bifurcated endografts to prevent or treat limb occlusion is a safe and effective adjunctive procedure, with outstanding long-term outcomes in terms of patency and reinterventions.

Objective: The aim was to identify predictors of adequate pre-operative sizing and planning for chimney endovascular aortic repair (ChEVAR) in order to reduce the incidence of persistent type Ia endoleaks (IaELs) without influencing chimney graft (CG) patency., Methods: Consecutive patients who underwent ChEVAR between January 2009 and December 2017 at a single centre were evaluated retrospectively. Included were patients treated with one device combination (Medtronic Endurant mated with Getinge Advanta V12/iCast) and placement of single or double CG. The freedom from IaEL related re-interventions and primary CG patency was estimated by measuring aortic stent graft oversizing (OS), total neck length (TNL), and a composite parameter (L-OS: TNL [mm] + OS [%])., Results: Seventy-three patients who underwent placement of 101 CGs (45 single, 28 double) met the inclusion criteria. The median radiological follow up was 25.5 (interquartile range [IQR] 12-48) months. Freedom from IaEL related re-intervention was achieved in 94.6% with a median OS of 38.5% (IQR 30%-44%, p = .004), TNL 19 mm (16-25 mm, p = .62), and L-OS 59 (51-65, p = .018). Primary CG patency was achieved in 95% of the cases with a median OS of 36% (29%-42%, p = .008), TNL 19 mm (15.5-26 mm, p = .91), and L-OS 57 (50-64, p = .005). By using the receiver operating characteristic curve, an optimal cut off to prevent IaEL related re-interventions was identified by an OS of 30% (p < .001; L-OS 55, p = .006) and to avoid CG stenosis/occlusions by OS 42% (p < .001; L-OS 65, p < .001). In multivariable analysis, aortic endograft OS was the only independent parameter preventive for IaEL related re-intervention (odds ratio, 0.78; 95% confidence interval, 0.61-0.99)., Conclusion: With the Endurant-Advanta V12/iCast combination, an aortic stent graft OS of at least 30% (range 30%-42%) should be used to avoid type Ia endoleaks and likewise to ensure CG patency., (Copyright © 2020 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.)

Background: Iliac limb stent grafting to the external iliac artery (EIA) is a commonly performed procedure in various situation during endovascular abdominal aneurysm repair (EVAR). However, this procedure is associated with a risk of graft occlusion. We evaluated risk factors affecting occlusion among patients who underwent iliac limb stent-graft extension to the EIA., Materials and Methods: We compared occluded limbs with patent limbs during the follow-up period using variables, including anatomical values, demographics, and other factors. Thereafter, we divided the occluded limbs into early and late occlusion subgroups. The main and subgroup analyses used the same variables. Survival analysis was performed to evaluate time-dependent risk factors for late limb occlusion., Results: From 2007 to 2016, 766 iliac limbs from 383 patients who underwent EVAR were initially included in our analysis. Among them, 134 iliac limbs underwent limb extension to the EIA. The limb extension was a significant risk factor for occlusion (hazard ratio = 6.34, P < 0.001). Occlusion occurred in 10 patients who underwent iliac limb extension. The size of common iliac artery (CIA) was associated with occlusion. The most significant factor was iliac bifurcation diameter (patent vs. occluded limbs, 21.6 ± 7.6 vs. 27.5 ± 9.5 mm, P = 0.005). Subgroup analysis revealed that the CIAs of the early occlusion subgroup were generally more tortuous (1.16 ± 0.33 vs. 1.47 ± 0.25, P = 0.091) and longer (53 ± 24 vs. 74 ± 9, P = 0.01) than those of the patent limb group. In addition, the EIA diameters of the late occlusion subgroup were narrower than those of the patent limb group (10.9 ± 1.6 mm vs. 9.1 ± 0.8 mm, P = 0.011). Using the log-rank test, those patients with an EIA diameter narrower than 10.1 mm had a higher risk for late limb occlusion (log-rank χ 2  = 5.73, P = 0.017) and the patients who did not take at least a single antiplatelet agent had a significantly higher chance of limb occlusion (log-rank χ 2  = 11.029, P = 0.001). In addition, the patients who did not take a statin had a higher risk for late limb occlusion (log-rank χ 2  = 7.41, P = 0.007)., Conclusions: Among patients who underwent EVAR with iliac limb extension, the CIA length affected early limb occlusion and predisposed patients to vessel injury or stent-graft kinking, and there was the possibility that CIA tortuosity was associated with a higher risk. The late occlusion subgroup had narrower EIAs than the patent limb group. Appropriate antiplatelet and statin therapy is expected to play a key role in the prevention of late limb occlusion after EVAR., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: To examine intraheartbeat displacements (IHD) and geometrical changes of endografts for abdominal aortic aneurysm repair over the course of years, defined as follow-up displacements (FUD), and to correlate them with computational fluid dynamics (CFD). Despite the widespread use of endovascular aneurysm repair (EVAR), we still know little about endograft behavior after deployment., Methods: Two cases, treated with either expanded polytetrafluoroethylene on a nitinol stent frame (PI) or with woven polyester fabric sutured to a stainless-steel Z stent skeleton (PII), were submitted to dynamic computed tomography angiography at 1, 12, and 60 months after implantation. After segmentation, IHD were computed as displacements of the reconstructed surface with respect to the diastolic instant. Similarly, FUD were studied using imaging techniques that align temporal successive segmentations. In addition, numerical simulations for blood dynamics were performed to compute viscous forces, specifically wall shear stress and time-averaged wall shear stress (TAWSS)., Results: IHD analysis showed slight translations without deformation for the PI endograft with respect to the stiffer stainless-steel endograft behavior of PII. FUD showed in PI motion of the metallic struts mainly focused on the distal main body of the endograft and in the zone overlapping with iliac branches. In PII, we observed a huge FUD in the middle and inferior-anterior regions of the main body. CFD analysis revealed changes of velocity patterns associated with remodeling of the iliac zone for PI and of the main body region for PII, where flow impinges the lumen wall and progressively induces deformation of the endograft wires. Measurement of TAWSS demonstrated flow disturbances in the enlarged region correlated with displacement analysis., Conclusions: Image-based displacement analysis associated with CFD enabled very subtle evaluations of endograft behavior on different temporal scales. This kind of study could be helpful both for physicians, forecasting evolution during the life span of the endograft, and manufacturers, giving them useful information about endograft implant performance and design., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: To assess in silicone juxtarenal aneurysm models the gutter characteristics and compression of different types of chimney graft (CG) configurations. Materials and Methods: Fifty-seven combinations of Excluder C3 or Conformable Excluder stent-grafts (23, 26, and 28.5 mm) were deployed in 2 silicone juxtarenal aneurysm models with 3 types of CGs: Viabahn self-expanding (VSE; 6 and 13 mm) or Viabahn balloon-expandable (VBX; 6, 10, and 12 mm) stent-grafts and Advanta V12 balloon-expandable stent-grafts (ABX; 6 and 12 mm). Setups were divided into 4 groups on the basis of increasing CG and main graft (MG) diameters. Two independent observers assessed gutter size and type as well as CG compression on computed tomography scans using postprocessing software. Results: In the smaller diameter combinations (6-mm CG and 23-, 26-, and 28.5-mm MGs), both VSE (p=0.006 to 0.050) and ABX (p=0.045 to 0.050) showed lower gutter areas and volumes compared with VBX. In turn, the VBX showed a nonsignificant tendency to decreased compression, especially compared to ABX. Use of the Excluder C3 showed a 6-fold increase in type A1 gutters (related to type Ia endoleak) as compared to the Conformable Excluder (p=0.018). Balloon-expandable stent-grafts (both ABX and VBX) showed a 3-fold increase in type A1 gutters in comparison with self-expanding stent-grafts (p=0.008). Conclusion: The current study suggests that use of the Conformable Excluder in combination with VSE chimney grafts is superior to the other tested CG/MG combinations in terms of gutter size, gutter type, and CG compression.

Purpose: To validate new computed tomography (CT)-applied software used to determine endograft limb position and apposition after endovascular aneurysm repair (EVAR). Materials and Methods: Twelve EVAR patients (mean age 81±6 years; 10 men) with distal stent-graft extensions for 15 (3 bilateral) type Ib endoleaks during follow-up were selected based on the availability of the following CT studies: pre-EVAR, 1 month, and the penultimate scan prior to the scan disclosing the type Ib endoleak. Twelve patients (mean age 82±7 years; 11 men) without endoleak and a similar interval between the primary EVAR procedure and the penultimate CT scan of the endoleak group were selected as controls using measurements from both endograft limbs (n=21, 3 excluded). Prototype Vascular Imaging Analysis software was adapted to calculate 6 parameters for the distal apposition zone: fabric distance, shortest apposition length, endograft diameter, iliac seal surface (ISS), iliac endograft apposition surface (IEAS), and percentage of iliac surface coverage (IEAS/ISS × 100). Measurements were performed on the preoperative, first postoperative, and penultimate/matched follow-up CT scans. Interobserver variability was assessed with the intraclass correlation coefficient (ICC). Continuous data are presented as the median [interquartile range (IQR) Q1, Q3]. Results: CTA follow-up was not significantly different between the endoleak and control groups [30 months (IQR 18, 58) vs 36 months (IQR 21, 59), p=0.843]. Interobserver agreement was good to excellent for all parameters (ICC 0.879-0.985). Preoperative anatomy and endograft dimensions on the first follow-up CTA scan did not differ significantly between the groups. When the penultimate CTA scan was compared with the first postoperative CT scan, endograft dimensions had significantly changed in the endoleak group; importantly, apposition was significantly decreased, and fabric distance was significantly increased, indicating limb retraction. Differences in changes in endograft dimensions were significant between the groups. Conclusion: New CT-applied software was introduced to visualize apposition and position changes of endograft limbs during follow-up. The software demonstrated good-to-excellent interobserver agreement and enabled accurate analysis of post-EVAR endograft dimensions. Significant changes in apposition and position were observed with the software on the penultimate CT scan prior to diagnosis of type Ib endoleak.

Purpose: To evaluate if the radial force of the double sealing ring of the Anaconda stent-graft induces dilatation in the perirenal aortic neck adjacent to the rings. Materials and Methods: This study evaluated the serial electrocardiogram-gated computed tomography scans of 15 abdominal aortic aneurysm patients (mean age 72.8±3.7 years; 14 men) who were treated electively using an Anaconda stent-graft. Follow-up scans were conducted before discharge and at 1, 6, 12, and 24 months after endovascular repair. Diameter and area were assessed perpendicular to the aortic centerline along the perirenal aortic neck, which was subdivided into 3 zones: the suprastent, the stent, and the infrastent zones. Measurements were performed independently by 2 experienced observers using dedicated 3-dimensional image processing software. Results: Between discharge and the 2-year follow-up the diameter and area remained stable in the suprastent zone [average diameter change: -0.1±0.4 mm (-0.4%±1.7%), p=0.893; average area change: -2.9±17.2 mm 2 (-0.7%±3.4%), p=0.946], increased in the stent zone [average diameter change: +1.9±1.0 mm (+7.3%±4.0%), p<0.001; average area change: +84.3±48.3 mm 2 (+15.5%±8.7%), p<0.001], and diverged in the infrastent zone [average diameter change: -0.8±2.2 mm (-2.3%±7.4%), p>0.99; average area change: -34.6±102.3 mm 2 (-4.1%±14.8%), p>0.99; increased in 4 patients, decreased in 9 patients]. Conclusion: After Anaconda implantation the infrarenal aortic neck accommodated to the expansion of the sealing rings at the stent zone. Below the stent zone the neck diameter decreased in the majority of patients, while an increase was related to downstream displacement of the main body. A decrease in size in the infrastent zone may contribute to durable sealing and fixation. A personalized follow-up scheme based on geometric neck remodeling should be feasible if our observations are confirmed in larger, long-term studies.

Purpose: To compare balloon-expandable covered stents (BECS) available for use as renal chimney grafts to the Advanta V12 approved for use with the Endurant endograft. Materials and Methods: A silicone model was manufactured based on preoperative computed tomography angiography (CTA) scans of a patient with a 7-cm juxtarenal aneurysm treated with an Endurant bifurcated endograft and an Advanta V12 covered stent for the 6-mm-diameter right renal artery. The model was placed in a flow box filled with a 37°C blood-mimicking solution equipped with a pulsatile pumping system (140/60 mm Hg). The tested BECS were the Advanta V12, the VBX, and the BeGraft+. A 36-mm-diameter Endurant II endograft with a 16-mm-diameter contralateral limb and a 6×59-mm BECS chimney graft were used in 9 consecutive tests (3 for each combination). After each implantation, the model was placed in the CT scanner, and 2 radiologists blinded to the test device independently measured the gutter areas and the patent chimney graft lumen at the level of the Endurant's suprarenal stent, at the level of the chimney's maximum curvature, and 10 mm inside the renal artery. The intraclass correlation coefficients (ICC) were calculated to assess interreader reliability. Results: The mean gutter areas were 19.3±7, 20.2±8, and 22.3±8 mm 2 for the Advanta, VBX, and BeGraft+, respectively (all p>0.05). At the level of the aortic endograft's suprarenal stent struts, the mean diameter of the Advanta V12, VBX, and BeGraft+ were 4.46±0.3, 4.12±0.4, and 4.12±0.3 mm, respectively (all p>0.05). At the level of the maximum chimney graft angulation, the mean diameters were 3.77±0.3, 4.16±0.1, and 3.74±0.3 mm, respectively (all p>0.05). In the right renal artery, the mean diameters were 3.91±0.2, 4.05±0.9, and 4.3±0.4 mm, respectively (all p>0.05). The ICCs varied between 0.7 and 0.9, indicating good agreement between readers. Conclusion: These in vitro findings showed comparable results between the Advanta V12 and the available BECS used in conjunction with the Endurant endograft according to the instructions for use. Further clinical evaluation is needed to confirm these results.

Background: Remodeling of the aortoiliac anatomy is a challenge to the long-term performance of stent grafts for endovascular aneurysm repair. Changes in vessel diameter and length can result in loss of seal at attachment sites, limb disunion, or kinking, with the development of high-pressure endoleaks, migration, or limb occlusion. The aim of this study was to assess the durability and conformability of the ultralow-profile INCRAFT AAA endograft (Cordis Corporation, Milpitas, Calif) during 5-year follow-up., Methods: From 2010 to 2011, there were 60 patients (median age, 74 years; range, 60-94 years) with intact abdominal aortic aneurysms who were enrolled in the INNOVATION trial to evaluate the safety, effectiveness, and durability of the INCRAFT AAA device. Clinical and technical success was assessed with protocol-specified, monitored follow-up clinic visits and core laboratory-assessed computed tomography (CT) at 1 month, 6 months, and 12 months after implantation and annually through 5 years thereafter. Diameter and angulation changes at the proximal aortic neck and diameter changes at the iliac attachment zones were measured in addition to the standard CT assessments., Results: Significant aortoiliac remodeling was observed throughout long-term follow-up after endovascular aneurysm repair. Proximal aortic neck diameter 15 mm below the lowest main renal artery increased from 23.5 ± 2.5 mm at 1 month to 27.3 ± 2.8 mm at 5 years (P = .002). Neck dilation >5 mm was observed in 8 of 38 patients with 5-year CT studies (21%). The aortic neck straightened, with angulation decreasing from 34 ± 14 degrees preoperatively to 31 ± 11 degrees at 1 month (P < .001) and to 20 ± 12 degrees at 5 years (P = .018). Straightening of the neck was most prominent in patients who presented with a high degree of preoperative angulation (r = 0.61; P < .001). Between 1 month and 5 years, iliac attachment zone diameter increased from 13.5 ± 1.9 mm to 15.0 ± 2.4 mm on the right (P = .002) and from 13.9 ± 2.3 mm to 16.8 ± 2.7 mm on the left (P < .001). During 5 years, 9 of 72 (13%) iliac arteries enlarged >5 mm. There was a significant relationship between main body oversizing and aortic neck enlargement (r = 0.42; P = .009). No similar association was observed between iliac limb oversizing and iliac dilation over time (r = 0.10 and P = .549, right side; r = 0.14 and P = .400, left side). There were no aneurysm-related deaths in the series. There were two type IA endoleaks, both of which were present on the 1-month CT scan and associated with challenging aortic neck anatomy. No patient experienced endograft migration or rupture through 5 years. Type IB endoleaks occurred in two patients, both accompanied by iliac artery dilation and loss of seal. Stent fracture occurred in two struts of the bare transrenal stent of one patient, without loss of fixation or seal. One patient experienced graft limb occlusion and was observed without intervention. There were three patients (5%) with aneurysm sac enlargement (>5 mm) through 5 years, each of whom had type II endoleak., Conclusions: Significant aortoiliac remodeling occurs after endograft implantation, including proximal aortic neck dilation, straightening of the neck, and iliac artery enlargement. The ultralow-profile INCRAFT device adapted well to these changes, with acceptably low 5-year rates of device-related endoleaks, endograft migration, and limb occlusion., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: To evaluate the 4-year results of the Endurant stent-graft in the treatment of abdominal aortic aneurysm (AAA) or common iliac artery aneurysm (CIAA)., Methods: Between June 2012 and January 2014, 50 consecutive Japanese AAA and CIAA patients were treated with the Endurant stent-graft at Tokyo Medical University Hospital., Results: Estimated freedom from overall mortality, aneurysm-related mortality, and secondary interventions at 4 years was 61.7%, 97.9%, and 78.6%, respectively. At 4 years, the maximum sac diameter decreased by >5 mm in 24% of the patients, remained stable in 52%, and increased by >5 mm in 24%. The average aneurysm sac reduction was 0.4 to 1.3 mm within 5 years. Multivariate analyses detected female gender (HR: 7.40, P=0.021) and type IV endoleak (HR: 5.34, P=0.009) as a significant risk factor for secondary intervention., Conclusions: Four-year clinical outcomes of the Endurant stent-graft remained positive in Japanese patients with AAA and CIAA, although 24% of the patients needed a secondary intervention. The aneurysm sac was stable in most of the patients, whereas the aneurysm sac reduction was small. These results suggest that careful imaging follow-up must be continued to determine the durability of the Endurant stent-graft in patients with small aneurysm sac reduction.

Objective: Manufacturers often recommend the iliac arteries as the distal landing zone in fenestrated or branched endovascular aortic repair (FB-EVAR) for thoracoabdominal aneurysm. It is not uncommon to choose distal landing at the infrarenal aorta for preservation of lumbar arteries or the inferior mesenteric artery (IMA); however, the safety and durability of this procedure have not been verified in the literature., Methods: Consecutive patients who underwent FB-EVAR with distal landing at the infrarenal aorta were reviewed retrospectively. The primary outcome measured any type IB endoleak over time. Secondary outcomes measured perioperative complications of paraplegia and bowel ischemia, preservation of lumbar artery and IMA, and degeneration of infrarenal aorta (diameter of infrarenal aorta at landing zone) and common iliac arteries (maximum diameters) over time., Results: Between August 2011 and August 2017, 40 patients (40% male with a mean age of 72 ± 8 years) affected by types I (37.5%), II (25.0%), III (20.0%), and V (17.5%) thoracoabdominal aneurysms were included. The mean aneurysm diameter was 6.4 ± 1.5 cm. There was no immediate or delayed type IB endoleak with mean follow-up period of 15 ± 18 months (range, 0-72 months). Postoperative complications included six (15%) spinal cord ischemia (five temporary and one permanent) and no mesenteric ischemia. There were three deaths (7.5%) within 30 days. Follow-up with computed tomography arteriography showed that 37 patients (92.5%) had at least one lumbar artery preserved. Out of the 31 preoperatively patent IMA, 23 (74.2%) were preserved. There was one incidental finding of new focal dissection distal to the stent graft end. Mean infrarenal aorta diameters were 24.8, 27.7, 27.7, and 29.4 mm immediately preoperatively, and at 1 and 2 years postoperatively, respectively. The mean maximal right common iliac diameters were stable and measured 15.8, 15.9, and 14.8 mm preoperatively, immediately postoperatively, and 1 year postoperatively, respectively. Mean maximal left common iliac diameters were also stable and measured 15.7, 15.9, and 14.7 mm preoperatively, immediately postoperatively, and at 1 year postoperatively, respectively., Conclusions: Our early experience showed that distal landing at the infrarenal aorta was secure in FB-EVAR with no type IB endoleak, although the observation of gradual infrarenal aortic degeneration mandates regular surveillance., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: The aims of the study are: 1) to define the incidence of intraoperative endograft limb stenosis >50% (ELS) after bifurcated EVAR, 2) to find risk factors for ELS considering morphology of aortic bifurcation and structural characteristics of endograft iliac limbs, and 3) to evaluate early and follow-up outcomes of intraoperative adjunctive endograft iliac stenting., Methods: Patients treated with bifurcated EVAR for abdominal aortic aneurysm were prospectively collected from 2005 to 2011. Patient demographics, clinical risk factors, preoperative aortic bifurcation morphology (minimum and maximum diameter [ABD], calcification [ABC]), endograft iliac limb parameters (diameters [ELDs], stent material, type of endograft), ratio between ELDs and ABD), perioperative ELS and results during follow-up were analyzed. Primary outcomes were incidence of perioperative ELS and risk factors for its occurrence. Considering adjunctive stenting procedure, secondary outcomes were technical success, 30-day and mid-term iliac endograft leg patency and clinical success., Results: Two hundred and forty-seven patients (men 233; mean age 74±7 years) were included. Mean maximum ABD was 28.9±12.9 mm. ABC was ≥50% in 56 (22.7%) cases. Median sum of ELDs was 31 mm (IQR 13-46). Endograft limb with stainless steel and nitinol stents was deployed in 69 (27.9%) and 178 (72.1%) patients. Median ELDs/ABD ratio was 1.2 (IQR: 0.9-1.5). ELS in aortic bifurcation occurred in 42 (8.5%) endograft limbs in 36 (14.6%) patients. ABD≤20 mm, ABC≥50%, ELDs≥30 mm, nitinol endograft stents and ELDs/ABD>1.4 were identified as possible positive predictive factors. At univariate and multivariate analysis, ELDs/ABD>1.4 resulted a positive prognostic factor for ELS (0.008 and 0.022, respectively). Forty-two adjunctive stents were deployed in 36 (14.6%) patients as intraoperative adjunctive procedure. Technical success, 30-day iliac endograft leg patency was 100%. Mean follow-up was 33 months (range 6-55 months) and mid-term clinical success and iliac endograft limb patency were 100%., Conclusions: ELS is a common event after EVAR with bifurcated endograft and ELDs/ABD>1.4 results positive predictive factor. Adjunctive stenting is a safe and effective procedure and ensures optimal mid-term endograft limb patency.

Objective: To evaluate immediate and long-term clinical outcomes of stenting for middle aortic syndrome (MAS) caused by Takayasu arteritis (TA)., Background: Studies of endovascular stenting for the treatment of MAS caused by TA are scare., Methods: Data from 48 consecutive TA patients (mean 33.3 ± 12.6 years) with MAS treated by stenting in our institution between January 2010 and July 2016 were collected and retrospectively analyzed. Thirty-day and long-term follow-up clinical outcomes after aorta stenting were assessed., Results: Stenting was successful in all patients. The mean stenosis and peak systolic pressure gradient of aorta lesions were reduced from 81.3 ± 8.0% and 70.7 ± 18.4 mm Hg to 14.7 ± 8.3% and 14.0 ± 5.8 mm Hg immediately after the 54 stents were implanted. One patient developed retroperitoneal hemorrhage and one developed flow-limiting dissection that involved bilateral renal arteries perioperatively. Both patients recovered without sequela. Compared with baseline, the ankle brachial index (0.92 ± 0.19 vs. 0.75 ± 0.22), mean systolic blood pressure (149.5 ± 19.1 vs. 179.0 ± 28.4 mm Hg) and antihypertensive drugs (1.1 ± 0.7 vs. 3.1 ± 0.9) significantly improved after an average follow-up of 3.1 years (all P < .001). A total of 5 (10.9%) patients developed in-stent restenosis, which were resolved by reintervention (restenting in 3 patients and re-angioplasty alone in 2 patients). No major adverse events occurred during follow up., Conclusions: Percutaneous aortic stenting is highly efficacious and safe in treating patients with MAS caused by TA with good immediate and long-term clinical outcomes., (© 2018 Wiley Periodicals, Inc.)

Purpose: To investigate the effect of distal stenotic lesions on flow patterns near a covered endovascular reconstruction of the aortic bifurcation (CERAB) configuration used in the treatment of aortoiliac occlusive disease., Method: Laser particle image velocimetry measurements were performed using in vitro models of the aortic bifurcation with and without a CERAB configuration in place. A hemodynamically nonsignificant stenosis (ΔP: 9 mm Hg), a hemodynamically significant (ΔP: 26 mm Hg) stenosis, and a total occlusion were simulated in the left iliac arteries. Velocity fields and time-averaged wall shear stress (TAWSS) were calculated., Results: Hemodynamically significant distal lesions did not influence the inflow patterns or TAWSS (0.5-0.6 Pa) in either model. However, hemodynamically significant distal stenotic lesions caused a 2-fold decrease in peak outflow velocities (control: 106 vs 56 cm/s, CERAB: 96 vs 54 cm/s) and a 3-fold decrease in TAWSS (control: 1.34 vs 0.44 Pa, CERAB: 0.75 vs 0.21 Pa). There was a 2-fold decrease in wall shear stress in the CERAB outflow compared with the control, independent of lesion severity., Conclusion: In the CERAB technique, adequate distal runoff is identified as an important parameter to ensure patency. This in vitro study showed that distal stenotic lesions influence aortic bifurcation outflow patterns and TAWSS more extensively in the CERAB configuration. Distal stenotic lesions could therefore increase the risk of disease progression and loss of stent patency. In vivo studies are necessary to confirm these observations.

Purpose: To compare in vivo the use of synchrotron radiation to computed tomography angiography (CTA) for the measurement of cross-sectional area (CSA) reduction of the aortic branch ostia caused by suprarenal stent-graft wires., Methods: This study was performed with a Zenith stent-graft placed in a phantom of the human aorta to simulate treatment of abdominal aortic aneurysm. Synchrotron radiation scans were performed using beam energies between 40 and 100 keV and spatial resolution of 19.88 μm per pixel. CSA reduction of the aortic branch ostia by suprarenal stent wires was calculated based on these exposure factors and compared with measurements from CTA images acquired on a 64-row scanner with slice thicknesses of 1.0, 1.5, and 2.0 mm., Results: Images acquired with synchrotron radiation showed <10% of the CSA occupied by stent wires when a single wire crossed a renal artery ostium and <20% for 2 wires crossing a renovisceral branch ostium. The corresponding areas ranged from 24% to 25% for a single wire and from 40% to 48% for double wires crossing the branch ostia when measured on CT images. The stent wire was accurately assessed on synchrotron radiation with a diameter between 0.38±0.01 and 0.53±0.03 mm, which is close to the actual size of 0.47±0.01 mm. The wire diameter measured on CT images was greatly overestimated (1.15±0.01 to 1.57±0.02 mm)., Conclusion: CTA has inferior spatial resolution that hinders accurate assessment of CSA reduction. This experiment demonstrated the superiority of synchrotron radiation over CTA for more accurate assessment of aortic stent wires and CSA reduction of the aortic branch ostia.

Background: The chimney technique has been successfully used to treat juxtarenal aortic aneurysms. The two main issues with this technique are gutter formation and chimney graft (CG) compression, which induce a risk for type Ia endoleaks and stent thrombosis, respectively. In this benchtop study, the geometry and renal artery flow of chimney endovascular aneurysm repair configurations were compared with chimney configurations with endovascular aneurysm sealing (ch-EVAS)., Methods: Seven flow phantoms were constructed, including one control and six chimney endovascular aneurysm repairs (Endurant [Medtronic Inc, Minneapolis, Minn] and AFX [Endologix Inc, Irvine, Calif]) or ch-EVAS (Nellix, Endologix) configurations, combined with either balloon-expandable or self-expanding CGs with an intended higher positioning of the right CG in comparison to the left CG. Geometric analysis was based on measurements at three-dimensional computed tomography angiography and included gutter volume and CG compression, quantified by the ratio between maximal and minimal diameter (D-ratio). In addition, renal artery flow was studied in a physiologic flow model and compared with the control., Results: The average gutter volume was 343.5 ± 142.0 mm 3 , with the lowest gutter volume in the EVAS-Viabahn (W. L. Gore & Associates, Flagstaff, Ariz) combination (102.6 mm 3 ) and the largest in the AFX-Advanta V12 (Atrium Medical Corporation, Hudson, NH) configuration (559.6 mm 3 ). The maximum D-ratio was larger in self-expanding CGs than in balloon-expandable CGs in all configurations (2.02 ± 0.34 vs 1.39 ± 0.13). The CG compression had minimal influence on renal volumetric flow (right, 390.7 ± 29.4 mL/min vs 455.1 mL/min; left, 423.9 ± 28.3 mL/min vs 410.0 mL/min in the control)., Conclusions: This study showed that gutter volume was lowest in ch-EVAS in combination with a Viabahn CG. CG compression was lower in configurations with the Advanta V12 than with Viabahn. Renal flow is unrestricted by CG compression., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Purpose: To examine the influence of device positioning and infrarenal neck diameter on flow patterns in the Nellix endovascular aneurysm sealing (EVAS) system., Methods: The transition of the aortic flow lumen into two 10-mm-diameter stents after EVAS creates a mismatched area. Flow recirculation may affect local wall shear stress (WSS) profiles and residence time associated with atherosclerosis and thrombosis. To examine these issues, 7 abdominal aortic aneurysm flow phantoms were created, including 3 unstented controls and 3 stented models with infrarenal neck diameters of 24, 28, and 32 mm. Stents were positioned within the instructions for use (IFU). Another 28-mm model was created to evaluate lower positioning of the stents outside the IFU (28-mm LP). Flow was visualized using optical particle imaging velocimetry (PIV) and quantified by time-averaged WSS (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) in the aorta at the anteroposterior (AP) midplane, lateral midplane, and renal artery AP midplane levels., Results: Flow in the aorta AP midplane was similar in all models. Vortices were observed in the stented models in the lateral midplane near the anterior and posterior walls. In the 32-mm IFU and 28-mm LP models, a steady state of vortices appeared, with varying location during a cycle. In all models, a low TAWSS (<10 -2 Pa) was observed at the anterior wall of the aorta with peak OSI of 0.5 and peak RRT of 10 4 Pa -1 . This region was more proximally located in the stented models. The 24- and 28-mm IFU models showed flow with a higher velocity at the renal artery inflow compared to controls. TAWSS in the renal artery was lower near the orifice in all models, with the largest area in the 24-mm IFU model. OSI and RRT in the renal artery were near zero for all models., Conclusion: EVAS enhances vorticity proximal to the seal zone, especially with lower positioning of the device and in larger neck diameters. Endobags just below the renal artery affect the flow profile in a minor area of this artery in 24- and 28-mm necks, while lower stent positioning does not influence the renal artery flow profile.

Six consecutive patients (3 men; mean age, 63 ± 14 years; age range, 38-81 years) with infrarenal abdominal aortic stenosis underwent unilateral or bilateral transradial approach for stenting of the aortic lesion. In 4 cases, isolated aortic stenting was performed through single transradial approach (in 2 cases with precise alignment to the proximal end of previously deployed iliac stents), whereas in the other 2 cases bilateral transradial approach was used for aortic stenting followed by bilateral stenting of the proximal iliac arteries. Either a "bare-on-the-wire" or a "support-catheter" technique was used, according to patient anatomy and technical requirements. The median follow-up was 14.3 months, at which time all patients had relief of symptoms without thromboembolic or bleeding complications. In this performance and safety evaluation, full transradial approach was effective and safe for treating infrarenal aortic stenosis that is isolated or associated with iliac disease.

Background: We aimed to review 50 consecutive Japanese abdominal aortic aneurysm (AAA) and common iliac aneurysm (CIAA) patients to evaluate the 2-year outcomes, particularly endoleak and aneurysm sac shrinkage, of the Endurant stent graft., Methods: Between June 2012 and January 2014, 50 consecutive Japanese AAA and CIAA patients underwent EVAR with the Endurant stent graft. Clinical outcomes of overall survival, aneurysm-related survival, and secondary intervention-free survival were analyzed; endoleaks and aneurysm sac changes were also evaluated., Results: The 2-year Kaplan-Meier estimates for overall survival, aneurysm-related survival, and secondary intervention-free survival were 85.4%, 97.7% with one device-related death, and 84.9%, respectively. Type I, II, and III endoleaks at any one point (all comers) after EVAR were detected in 2 (4%), 6 (12%), and 3 (6%) patients, respectively, whereas type IV endoleak was detected in 19 (38%) patients. The percentage of patients with significant sac shrinkage was only 19% (7/37) of the patients at 2 years. Multivariate analysis detected hypertension as a significant factor affecting aneurysm sac shrinkage (OR: 0.09, 95% CI: 0.001-0.99, P=0.049)., Conclusions: The Endurant stent graft has demonstrated consistently successful clinical performance in Japanese patients for 2 years. However, the incidence of type IV endoleak was high, while the percentage of significant sac shrinkage was low. Careful and longer follow-up is required to determine the durability of the Endurant stent graft in Japanese patients.

Background: Ovation aortic stent-graft system is a new device for the endovascular treatment of Abdominal Aortic Aneurysms achieving fixation via a 35-mm long, rigid anchored suprarenal stent and sealing stent at the infrarenal level by a means of a polymer-filling pair of inflatable O-rings, which cause narrowing of flow lumen and regional stenosis. Thus, concerns have been raised regarding hemodynamic consequences associated with this new design. Our preliminary report showed no significant increase of aortic pulse wave velocity (aPWV) immediately after implantation of the ovation in 3 patients. We studied further the hemodynamic implications of the Ovation implantation in 6 patients for a follow-up of 6 months., Methods: A brachial cuff-based automatic oscillometric device (Mobil-O-Graph; IEM, Stolberg, Germany) was used to perform noninvasively pulse wave analysis and stiffness estimation. Measurements were held preoperatively in 6 patients treated for abdominal aortic aneurysm, at the end of the first postoperative week, first and sixth postoperative month. Changes in systolic and diastolic blood pressure (cSyst, cDiast), heart rate, aPWV, augmentation index (AI@75), augmentation pressure (AP), and in the amplitude ratio of the reflected-to-forward pressure waves (reflection magnitude, RM) were recorded and compared. Significant change in any parameter was examined via analysis of variance repeated measures., Results: The cSyst was 132 ± 19.6, 127 ± 17.63, 131.3 ± 19.96, and 129.83 ± 31.72 mm Hg (P = 0.81) and cDiast was 88 ± 10.58, 86.83 ± 11.72, 89.83 ± 16.01, and 98.5 ± 24.56 mm Hg (P = 0.40). The heart rate showed an increasing yet nonsignificant tendency (67 ± 10.60, 75.1 ± 8.63, 74.33 ± 8.89, and 70.66 ± 6.65 beats/min, 0.27). The aPWV remained constant (11.61 ± 1.88, 11.6 ± 1.74, 11.8 ± 2.08, and 11.85 ± 2.30 m/sec, P = 0.79). Similarly, RM (71.16 ± 9.94, 60.66 ± 11.79, 61.5 ± 14.47, and 64.5 ± 3.78), AI@75 (33.83 ± 12.25, 22.16 ± 7.93, 27.83 ± 11.23, and 19.5 ± 14.72), and AP (18.33 ± 10.36, 9.83 ± 4.91, 11.5 ± 9.22, and 12 ± 15.08 mm Hg) remained practically unaltered during the follow-up period (P value: 0.79, 0.25, 0.10, and 0.27), respectively., Conclusions: The implantation of the Ovation stent graft does not cause increase in aortic stiffness or in pulse wave reflection in the mid-period. The rationale of investigating noninvasively the impact of aortic stent grafts on the mechanical properties and the hemodynamic parameters should be encouraged because such findings may contribute to further development of newer endograft designs., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background and Aim of the Study: Bioengineered living autologous valves with remodeling and growth capacity represent a promising concept for future cardiac and venous valve repair. A meticulous understanding of the mechanisms involved in recellularization and remodeling is essential for the safe and efficient clinical translation of this technology. In this context, the first investigations of bioengineered vascular grafts in immune-incompetent or transgenic rodents represented an important step. However, the in-vivo assessment of bioengineered synthetic scaffold-based (biodegradable) valve replacements in rodent models has not been achieved to date., Methods: Miniaturized monocuspid PGA (polyglycolic acid)-P4HB (poly-4-hydroxybutyrate)-based valves were created, incorporated into metallic stents (length 2.0 mm, diameter 1.1 mm) and introduced into catheter-based implantation devices. Wistar outbred rats (n = 8) underwent a laparotomy, abdominal aorta arteriotomy and valve delivery into the abdominal aorta. Valve placement and function were evaluated following deployment using ultrasound (Doppler- and M-mode). Explanted tissues were analyzed both macroscopically and histopathologically., Results: No significant physiological or hemodynamic changes were observed, including heart rate, pressure gradients, velocity values and cardiac output before and after valve implantation. The cross-sectional area at the level of the stented valve was reduced by 22%. Valvular leaflet oscillation was observed in two animals, and thrombus formation in the stent was observed in one animal. Histological evaluation revealed cellular infiltration within 3 h in vivo, and no signs of thrombus deposition on the valvular surface., Conclusions: This study demonstrated the technical feasibility of the transcatheter implantation of bioengineered stented miniaturized valves into the infrarenal rat aorta, without affecting the animal's physiological and hemodynamic variables and with valvular oscillation in part of the implants. These results could serve as a basis for the implementation of a chronic rat in-vivo model for mechanistic studies in bioengineered valvular tissues under systemic hemodynamic conditions. Video 1: 2D ultrasonographic projection revealing graft's leaflet oscillation.

Purpose: To examine the changes in distraction force following relining of a conventional abdominal aortic stent-graft with a type IIIb endoleak using the Nellix endovascular sealing device compared to a unilateral stent-graft., Methods: Relining is often used to repair type IIIb endoleaks, but the consequences to graft stability are unknown. A mathematical model was constructed based on pressure and volume flow through the stent-grafts, incorporating recognized distraction force equations. Steady flow was presumed at peak systolic pressures to calculate the maximum distraction force, with gravity ignored. Distraction forces for 28- to 36-mm-diameter stent-graft bodies with 16-mm limbs were calculated and compared to forces following relining with single and double Nellix devices or the Renu unilateral device., Results: Distraction forces for the 28-, 32-, and 36-mm stent-grafts prior to relining were 5.99, 10.21, and 14.99 N, respectively. Similar forces were reported after relining with bilateral Nellix devices (5.86, 10.08, and 14.86 N, respectively). However, use of a unilateral Nellix increased the distraction forces to 9.92, 14.14, and 18.92 N, respectively. These were comparable to the increase observed after relining with a Renu unilateral stent-graft (9.87, 14.09, and 18.86 N, respectively). The proportional increase in distraction force for a unilateral relining ranged from 26% to 66%, with the greatest increase noted in the smaller diameter main bodies., Conclusion: Relining a stent-graft with a type IIIb endoleak using bilateral Nellix devices does not increase the distraction force. However, a unilateral Nellix device or the Renu system could theoretically increase the distraction force by up to 66%, potentially risking migration and type Ia endoleak. In clinical practice, these results suggest that a relining with bilateral Nellix may have benefits over the Renu unilateral stent-graft., (© The Author(s) 2016.)

Objective: The aim was to assess the early and mid-term safety and clinical outcomes of a modified sandwich-graft technique (MSGT) that employed the Aorfix and Viabahn stent-grafts to preserve hypogastric flow in cases of complex aortoiliac and isolated common iliac artery (CIA) aneurysms including internal iliac artery (IIA) ostium who were not suitable for an iliac branch device (IBD)., Methods: A review of prospective collected data of all consecutive cases of treatment of complex aortoiliac or isolated CIA aneurysms including IIA ostium using the MSGT to preserve the hypogastric flow in three European centres between April 1, 2010, and December 31, 2013, was performed. All patients included were unfit for open repair and not suitable for an IBD., Results: During the study period, 21 patients met the study criteria and had 25 MSGTs. The mean follow-up duration was 17.2 months. The technical success rate was 100%, with no perioperative mortality and stent-graft or MSGT-treated IIA occlusions. There were two cases with Type Ib endoleaks and one Type III endoleaks intraoperatively that were successfully managed. There was also no reported early and late pelvic ischaemia. The primary patency rate was 90.5%, and two cases of MGST treated IIA occlusions with no reported symptoms of pelvic ischaemia during follow-up., Conclusions: MSGT was a safe and feasible strategy to preserve hypogastric flow in cases of complex aortoiliac and isolated CIA aneurysms including IIA ostium and who were not suitable for IBD, with encouraging early and mid-term outcomes., (Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: Endovascular abdominal aortic repair requires an adequate sealing zone. The chimney graft (CG) technique may be the only option for urgent high-risk patients who are unfit for open repair and have no adequate sealing zone. This single-center experience provides long-term results of CGs with endovascular repair for urgent and complex aortic lesions., Methods: Between July 2006 and October 2012, 51 patients (16 women) with a median age of 77 years (interquartile range, 72-81 years), were treated urgently (within 24 hours [61%]) or semiurgently (within 3 days [39%]) with endovascular aortic repair and visceral CGs (n = 73). Median follow-up was 2.3 years (interquartile range, 0.8-5.0 years) for the whole cohort, 3 years for 30-day survivors, and 4.8 years for patients who are still alive., Results: Five patients (10%) died within 30 days. All of them had a sacrificed kidney. All-cause mortality was 57% (n = 29), but the chimney- and procedure-related mortality was 6% (n = 3) and 16% (n = 8), respectively. Chimney-related death was due to bleeding, infection, renal failure, and multiple organ failure. There were two postoperative ruptures; both were fatal although not related to the treated disease. The primary and secondary long-term CG patencies were 89% (65 of 73) and 93% (68 of 73), respectively. Primary type I endoleak (EL-I) occurred in 10% (5 of 51) of the patients, and only one patient had recurrent EL-I (2%; 1 of 51). No secondary endoleak was observed. Chimney-related reintervention was required in 16% (8 of 51) of the patients because of EL-I (n = 3), visceral ischemia (n = 4), and bleeding (n = 2). The reinterventions included stenting (n = 5), embolization (n = 3), and laparotomy (n = 2). Thirty-one visceral branches were sacrificed (9 celiac trunks, 9 right, and 13 left renal arteries). Among the 30-day survivors, 8 of 17 patients (47%) with a sacrificed kidney required permanent dialysis; of these, seven underwent an urgent index operation. The aneurysm sac shrank in 63% (29 of 46) of cases., Conclusions: The 6% chimney-related mortality and 93% long-term patency seem promising in urgent, complex aortic lesions of a high-risk population and may justify a continued yet restrictive applicability of this technique. Most endoleaks could be sealed endovascularly. However, sacrifice of a kidney in this elderly cohort was associated with permanent dialysis in 47% of patients., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective/background: To investigate experimentally the arterial wall/device compliance mismatch of four stent-graft devices and a multilayer flow modulator within the supra- and infrarenal locations for the treatment of abdominal aortic aneurysms (AAA)., Methods: Five devices (MFM, EndurantII, Excluder, Zenith, and Fortron) were tested under physiological flow conditions within a flow simulator system comprising of a patient-specific thin-walled flexible AAA perfusion model with replicated intraluminal thrombus, supported by the spinal column. Devices were submitted to circumferential force tests and implanted in the perfusion model for circumferential arterial pressure/diameter measurements. Parameters, including radial resistive force, supra-/infrarenal compliance, pulsatile arterial energy loss (PAEL), pulse wave velocity (PWV), and wave reflection coefficient (Γ), were computed to characterise the devices' performance., Results: The Zenith and EndurantII devices had the highest radial resistive force (up to 3 N/cm), while the Fortron device had the lowest (0.11 N/cm). Supra- and infrarenal compliance varied between 6.9-5.1 × 10(-4)/mmHg and 4.8-5.4 × 10(-4)/mmHg, respectively. Two devices (EndurantII and Excluder) significantly decreased infrarenal compliance by 13-26% (p < .001). Four devices increased the PAEL by 13-44% (p < .006). The PWV ranged from 10.9 m/s (MFM; p = .164) to 15.1 m/s (EndurantII; p < .001). There was an increase of 8-238% (p < .001) in the reflection coefficient for all devices., Conclusion: Commercially available endovascular devices lower the aortic wall compliance after implantation. The MFM was found to be the most compliant in the suprarenal region, while the Fortron device was the most compliant in the infrarenal region. Choosing the most compliant devices for treating AAAs produces positive gains in the aortic elastic recoil, thus minimising the device related complications., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Aortoiliac arterial occlusive disease is frequently encountered in the management of lower limb vascular insufficiency. We report our experience with covered balloon-expandable stents for treatment of TASC D lesions of the abdominal aorta and common iliac arteries., Methods: A retrospective study of 30 patients who underwent aortoiliac stenting with the Atrium Advanta V12 from March 2010 to September 2012 was conducted. Patient demographic data, clinical signs and symptoms and procedural details were recorded. Outcomes assessed were primary patency, secondary patency, technical success, complications, limb salvage and survival., Results: Median age was 67 years (range 48-84) and 40% of patients underwent treatment for critical limb ischaemia. Median follow-up was 13 months (range 3-38 months). Stent configuration comprised of long iliac stents in 20 patients, a large diameter aortic stent with iliac stenting in six patients, and aortic stent alone in four patients. Radiological success was achieved in 100% and the complication rate was 6%. Primary patency at 6, 12 and 24 months was 97%, 90% and 79%, respectively. Four cases of in-stent stenosis were reported, with three of these undergoing re-interventions resulting in a secondary patency rate of 97% at the end of follow-up. One patient death occurred within the follow-up period., Discussion: This case series demonstrates that treatment of complex aortoiliac occlusive disease with covered balloon-expandable stents can have acceptable results with good patency and good clinical outcome. Secondary patency rates are comparable to open surgical revascularisation, with lower morbidity., (© The Author(s) 2015.)

Objective: We compared the outcomes and the durability of endovascular recanalization (EVR) with the Viabahn (W. L. Gore and Associates, Flagstaff, Ariz) covered stent graft vs traditional aortobifemoral or aortofemoral bypass grafting for complex aortoiliac occlusions., Methods: Between 2008 and 2014, 11 unilateral iliac occlusions and 11 aortobiiliac occlusions were treated by EVR. Also collected were data from the last 21 consecutive patients treated in the same period by aortofemoral (n = 6) or aortobifemoral (n = 15) bypass grafting. In accordance with the TransAtlantic Inter-Society Consensus II (TASC II) document, only patients with type D lesions were considered. Kaplan-Meier estimates for patency were calculated, and Cox proportional hazard modeling was performed., Results: The difference in risk factors between the groups was not significant. General anesthesia was required in 100% of the surgical group, and local or locoregional anesthesia was used for EVR. Suprarenal aortic cross-clamping was required in nine of the open surgical procedures (41%). A brachial percutaneous approach was performed in all patients undergoing EVR, and technical success was 100% in both groups. All of the attempts at EVR were successful. At the 2-year follow-up, primary patency did not differ significantly between the endovascular (91%) and surgical (95%) groups. This was seen in the univariate model (hazard ratio [HR], 0.27; 95% confidence interval [CI], 0.02-2.95; P = .28) and in the multivariate model (HR, 0.77; 95% CI, 0.06-10.07; P = .84) for group (HR, 0.58; 95% CI, 0.04-7.72; P = .68), age (HR, 0.89; 95% CI, 0.73-1.08; P = .24), symptoms (HR, 1.98; 95% CI, 0.42-9.46; P = .39), and occlusion (HR, 3.22; 95% CI, 0.51-20.35; P = .21). The average hospital length of stay was shorter for patients treated with ERV than for those treated with open surgery (3.9 ± 2.2 vs 5.8 ± 3.1 days, respectively; P = .03). The complication rate was 4% for EVR vs 18% in the surgical group (P = .32)., Conclusions: At 2 years of follow-up, the results of endoluminal bypass grafting with the Viabahn stent to treat complex aortoiliac disease are promising. Longer-term results are needed to fully evaluate the potential benefits and longer-term patency., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: This study evaluated changes in aortic neck diameter after endovascular aneurysm repair (EVAR) using a balloon-expandable stent (BES) endograft compared with a commercially available self-expanding stent (SES) endograft. We hypothesized that forces applied to the aortic neck by SES endografts may induce aortic neck enlargement over time and that such enlargement may not occur in aneurysm patients treated with a device that does not use a proximal SES., Methods: This was a retrospective quantitative computed tomography (CT) image analysis of patients treated with the Nellix (Endologix, Irvine, Calif) BES (n = 49) or the Endurant II (Medtronic, Minneapolis, Minn) SES (n = 56) endograft from 2008 to 2010. Patients with preimplant, postimplant, and at least 1-year serial CT scans underwent quantitative morphometric assessment by two independent vascular radiologists blinded to the outcome results. Changes in the infrarenal neck over time were compared with the suprarenal aorta for each patient., Results: Follow-up extended to 4.8 years for the BES and to 4.6 years for the SES, with no significant difference in median follow-up time (34 months for BESs and 24 months for SESs; P = .06). There were no differences in preimplant neck diameter (25.2 ± 0.9 mm vs 25.7 ± 1.1 mm; P = .54) or length (27.7 ± 3.7 mm vs 23.6 ± 3.7 mm; P = .12) between BESs and SESs at baseline. After implantation, neck diameter increased by 1.1 ± 0.5 mm in BES patients and 2.6 ± 0.5 mm in SES patients (P = .07) compared with the preoperative diameter. At 3 years, neck diameter increased by 0.5 ± 0.9 mm in BES patients and by 3.8 ± 1.0 mm in SES patients (P = .0002) compared with the first postoperative CT scan. The annual postimplant rate of increase in the infrarenal neck diameter was fivefold greater in SES patients (1.1 ± 0.1 mm/y) than in BES patients (0.22 ± 0.04 mm/y; P < .0001). There were no significant differences in the diameter of the suprarenal aorta at baseline or at 3 years and no differences in the annual rate of change in suprarenal aortic diameter between BES and SES endografts., Conclusions: EVAR using SES endografts resulted in progressive infrarenal aortic neck enlargement, whereas EVAR using BES endografts resulted in no neck enlargement over time. These data suggest that infrarenal neck enlargement after EVAR with SES endografts is likely related to the force exerted by SES elements rather than disease progression in the infrarenal neck., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

At the point when the aorta ruptures suddenly, as opposed to as the after-effect of injury, it is for the most part in aortic aneurysm. Aortic aneurysm rupture happens when the wall stress surpasses the strength of the vascular tissue. Intraluminal thrombus (ILT) may have advantages as it can absorb tension and decrease aortic aneurysm wall stress. This study aims to investigate the presence and growth effects of ILT on the wall stress in a stented aneurysm in one heart cycle. A virtual stented aneurysm model with ILT was made to study the flow and wall dynamics using fluid-structure interaction (FSI) analysis. Wall stresses at the center line of media layer of aorta thickness were calculated by two-dimensional axisymmetric finite element analysis. Calculations were executed as thrombus elastic modulus increased from 0.1 to 2 MPa and calculations were repeated as thrombus depth was increased in 10% increment until thrombus filled the whole aneurysm cavity. The von Mises stresses were compared in three sections, namely proximal, aneurysm and distal sections in the abdominal aorta. The wall stress showed its maximum value during a peak flow and pressure and gradually decreased as the pressure and velocity of blood reduced in all three aforementioned sections. As the intraluminal thrombus depth increased from 10% to 100%, the wall stress in distal, proximal and centre of aneurysm during one heart cycle was decreased. Furthermore, increasing the elastic modulus of thrombus from 10% to 100% triggered a reduction in wall stress in proximal, centre of intraluminal thrombus and distal regions during one heart cycle. The achievements of this study may have implications not only for understanding the wall stress in ILT, but also for providing more detailed information about aortic aneurysm with intraluminal thrombus and can help surgeons to do their best.

Objective: Secure fixation of endovascular stent grafts is essential for successful endovascular aneurysm repair. Hemodynamic distraction forces are generated by blood pressure and blood flow and act against fixation force to encourage migration that may eventually lead to late stent graft failure. The aim of this in silico study was to determine which morphologic features were associated with greater distraction force., Methods: Computer models of 54 in situ fenestrated stent grafts were constructed from postoperative computed tomography scans by use of image processing software. Computational fluid dynamic analysis was then performed by use of a commercial finite volume solver with boundary conditions representative of peak systole. Distraction force results were obtained for each component of the stent graft. Distraction force was correlated with lumen cross-sectional area (XSA) at the inlet and outlet of components and was compared between groups of components, depending on the magnitude of four predefined angles within the aortoiliac territory that we describe in detail., Results: Median total resultant distraction force (RDF) acting on the fenestrated proximal bodies was 4.8 N (1.3-15.7 N); bifurcated distal bodies, 5.6N (1.0-8.0 N); and limb extensions, 1.7 N (0.6-8.4N). Inlet XSA exhibited strong, positive correlation with total RDF in proximal body and distal body components (Spearman correlation coefficient ρ, 0.883 and 0.802, respectively). Outlet XSA exhibited a similarly strong, positive correlation with total RDF in limb extension components (ρ, 0.822). Outlet angulation ≥ 45 degrees was associated with greater total RDF in the limb extension components only (P = .004)., Conclusions: For a given blood pressure, XSA was the most important morphologic determinant of total RDF. Angulation within the aorta was not large enough to influence this, whereas iliac angulation affecting outlet angulation of limb extension components was associated with significantly greater total RDF., (Copyright © 2014 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine conformability of stent-grafts in endovascular aneurysm repair (EVAR) using centerline of flow measurements and to compare conformability in patients with severe aortoiliac tortuosity., Methods: From 2012 to 2013, 111 consecutive patients (98 men; mean age 75.4±7.7 years) underwent endovascular aneurysm repair with Endurant I and II and Zenith Flex, LP, and Spiral Z stent-grafts; their pre- and post-EVAR computed tomography (CT) studies were retrospectively analyzed using quantitative 3-dimensional imaging software. The length between the lowest renal artery and the iliac bifurcation was measured using centerline of flow and was defined as the treatment length (TL). The difference in TLs pre and post EVAR were compared as a surrogate to evaluate endograft conformability., Results: A total of 203 pre and post EVAR aortoiliac TLs were measured (99 Endurant I, 20 Endurant II, 32 Flex, 6 LP, and 42 Spiral Z). Overall, there was a mean difference of 5.0±7.3 mm or 2.6%±3.9% between the pre- and post-EVAR TLs (p<0.001). No statistically significant difference in TLs was observed among the various stent-grafts (p=0.115). In 40 patients with severe aortoiliac tortuosity, the post-EVAR TL was 16.2±5.5 mm or 8.0%±2.7% shorter than the pre-EVAR TL (p<0.001); again, there was no difference in TLs among the various devices implanted (p=0.737)., Conclusion: Overall, there was no difference in treatment lengths before and after EVAR among different stent-grafts, suggesting similar conformability. Interestingly, patients with severe aortoiliac tortuosity were found to have significantly shorter post-EVAR treatment lengths compared to before EVAR, which should be considered when planning EVAR.

Aim: The influence of the relative iliac limb length of an endograft (EG) on the displacements forces (DF) predisposing to adverse effects are under-appreciated in the literature. Therefore, we conducted a computational study to estimate the magnitude of the DF acting over an entire reconstructed EG and its counterparts for a range of main body-to-iliac limb length (L1/L2) ratios., Methods: A customary bifurcated 3D model was computationally created and meshed using the commercially available ANSYS ICEM (Ansys Inc., Canonsburg, PA, USA) software. Accordingly, Fluid Structure Interaction was used to estimate the DF. The total length of the EG was kept constant, while the L1/L2 ratio ranged from 0.3 to 1.5., Results: The increase in L1/L2 slightly affected the DF on the EG (ranging from 3.8 to 4.1 N) and its bifurcation (4.0 to 4.6 N). However, the forces exerted at the iliac sites were strongly affected by the L1/L2 values (ranging from 0.9 to 2.2 N), showing a parabolic pattern with a minimum for 0.6 ratio., Conclusion: It is suggested that the hemodynamic effect of the relative limb lengths should not be considered negligible. A high main body-to-iliac limb length ratio seems to favor hemodynamically a low bifurcation but it attenuates the main body-iliac limbs modular stability. Further clinical studies should investigate the relevant value of these findings. The Bolton Treovance(®) device is presented as a representative, improved stent-graft design that takes into account these hemodynamic parameters in order to achieve a promising, improved clinical performance.

Purpose: To evaluate the late results of endovascular aneurysm repair (EVAR) with the endografts currently in use and compare outcomes to older devices., Methods: Clinical, demographic, and imaging data on consecutive patients undergoing elective EVAR from January 1997 to December 2011 at a single center were retrieved from an electronic database and reviewed. Newer stent-grafts (NSG) were defined as those introduced after 2004 (second-generation Excluder and Anaconda) or currently in use without modifications (Zenith, Endurant). Of the 1412 consecutive patients (1290 men; mean age 73 years) who underwent elective EVAR in a tertiary university hospital, 882 were treated with NSGs and 530 with older stent-grafts (OSGs)., Results: In the NSG group, the abdominal aortic aneurysms (AAA) were larger (55.7 vs. 53.2 mm, p<0.0001) and the patients were older (p<0.0001) and less frequently smokers or had pulmonary disease, while hypertension and diabetes were more frequent (all p<0.0001). Thirty-day mortality was 0.8% in the NSG group vs. 1.1% in the OSG group (p=NS). Follow-up ranged from 1 to 174 months (mean 54.1±42.4); the OSG patients had longer mean follow-up compared to the NSG group (80.2±47.9 vs. 38.4±29.1 months, p<0.0001). All-cause survival rates were comparable in both groups. Freedom from late conversion (96.1% vs. 89.1% at 7 years, p<0.0001) or reintervention (83.6% vs. 74.2% at 7 years, p=0.015) and freedom from AAA diameter growth >5 mm (p=0.022) were higher in the NSG group. In adjusted analyses, the use of a new-generation device was a negative independent predictor of reintervention [hazard ratio (HR) 0.67, 95% confidence interval (CI) 0.49 to 0.93, p=0.015] and aneurysm growth (HR 0.63, 95% CI 0.45 to 0.89, p=0.010)., Conclusion: Newer-generation endografts can perform substantially better than the older devices. In the long term, incidences of reintervention, conversion, and AAA growth are decreased in patients treated with devices currently in use. However, the need for continuous surveillance is still imperative for all endografts.

Objective: The hemodynamic consequences of misaligned stent-grafts (SG) in fenestrated endografts (EG) have not been adequately studied. Our aim was to study the hemodynamic effects of positional variations of SG, investigating the potential influence on the total displacement forces acting on the EG and the shear stress values at the stented segments., Methods: This was a computational study. An idealized EG model with two renal fenestrations was computationally reconstructed and centrally extended up to the suprarenal level to treat a suprarenal aneurysm. The misalignment of SG was represented by a variable take-off angle between the SG and the EG centerline axis, corresponding to angles of 90°, 176°, 142°, 38°, and 4°, respectively. Accordingly, the maximum EG displacement forces and the shear stress within the stented segments were calculated, using commercially available software., Results: The variable positions of the SG caused no effect on the maximum displacement force acting on the EG, being quite steady and equal to 5.55 N. On the contrary, the values of maximum shear stress acting on the stented segments were influenced by their orientation. The narrow transition zone between the distal end of the mating stent and the target artery showed higher stresses than any other segment. The right-angle take off SG position (90°) was associated with the lowest stresses (12.5 Pa), whereas the highest values were detected at 38° and 142° (16.5 and 16.1 Pa, respectively). The vessel segments distal to the SG exhibited constantly lower stress values (1.9-2.2 Pa) than any other segment., Conclusion: We detected differences in the values of shear stress exerted on the stented arteries, depending on different positions that SG can adapt after the deployment of fenestrated EG. The pathophysiologic implication of our findings and their potential association with clinical events deserve further investigation and clinical validation., (Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

We report on emergency percutaneous renal artery stenting in two children who developed acute anuria due to bilateral renal artery stenosis and near-total occlusion. In both children, urine output could be reestablished following the procedure. One patient died from persistent severe cardiac failure. Emergency stenting is feasible, and may buy time for future procedures., (Copyright © 2013 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.)

Objective: Chimney grafts have proven useful for urgent endovascular repair of juxtarenal aortic aneurysms. Stenting of juxtarenal aortic occlusive disease is not routinely advocated due to the risk of visceral artery obstruction. We report on the potential applicability of chimney grafts in 10 patients with juxtarenal aortic stenosis or occlusion. To our best knowledge, chimney grafts have not been applied previously in this challenging setting., Methods: Ten high-risk female patients (mean age, 68 years) with severe stenosis or occlusion of the aorta at the level of the visceral arteries were offered stenting. "Chimney" stents or stent grafts (20-40 mm long) were implanted from a brachial approach into visceral arteries that needed to be covered by the aortic stent. The chimney stents were then temporarily obstructed by balloon catheters to prevent visceral embolization until the aortic stent or stent graft was deployed., Results: All procedures were technically successful, and patency was obtained in all visceral arteries and the aorta without distal embolization. One patient died after 9 days of acute heart failure. The nine surviving patients presented no complications, and all stented vessels remained patent at up to 6 years. Another patient died after 5.5 years due to lung cancer. All three patients with renal impairment have improved renal function, and a reduction in antihypertensive medication has been possible., Conclusions: Chimney grafts may allow stenting of juxtarenal aortic occlusive disease by protecting the patency of visceral arteries. Further evaluation with more patients and longer follow-up is required., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

The long-term success of the endovascular procedure for the treatment of Abdominal Aortic Aneurysms (AAAs ) depends on the secure fixation of the proximal end and the geometry of the stent-graft (SG) device. Variations in SG types can affect proximal fixation and SG hemodynamics. Such hemodynamic variations can have a catastrophic effect on the vascular system and may result from a SG/arterial wall compliance mismatch and the sudden decrease in cross-sectional area at the bifurcation, which may result in decreased distal perfusion, increased pressure wave reflection and increased stress at the interface between the stented and non-stented portion of the vessel. To examine this compliance mismatch, a commercial SG device was tested experimentally under a physiological pressure condition in a silicone AAA model based on computed tomography scans. There was a considerable reduction in compliance of 54% and an increase in the pulse wave velocity of 21%, with a significant amount of the forward pressure wave being reflected. To examine the SG geometrical effects, a commercial bifurcated geometry was compared computationally and experimentally with a geometrical taper in the form of a blended section, which provided a smooth transition from the proximal end to both iliac legs. The sudden contraction of commercial SG at the bifurcation region causes flow separation within the iliac legs, which is known to cause SG occlusion and increased proximal pressure. The blended section along the bifurcation region promotes a greater uniformity of the fluid flow field within the distal legs, especially, during the deceleration phase with reduced boundary layer reversal. In order to reduce the foregoing losses, abrupt changes of cross-section should be avoided. Geometrical tapers could lead to improved clinical outcomes for AAA SGs., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Aim: This paper presents the recent data of the largest series (20 patients) of endovascularly treated patients and the first long term data of 9 patients with severe aortoiliac occlusive disease., Methods: Between 2003 and 2012, 20 consecutive patients (14 men; 70 %) with Leriche syndrome underwent recanalization with solely endovascular means at our centre. The treatment strategy comprised the antegrade (transbrachial) recanalization of the occluded segments followed by retrograde (transfemoral) angioplasty with selective stent placement in the infrarenal aorta and primary stent placement in the iliac arteries. Before discharge, after 30 days and every year after the procedure, a clinical, as well as a duplex ultrasonographic examination including measurement of the ankle-brachial index was done., Results: Bilateral success was achieved in 17 patients (85%). Unilateral success was achieved in three patients (15%). In one patient (5%) an early reocclusion of the stented segments occurred, necessitating bypass grafting. In nine patients long term data were evaluated. Here, the ankle brachial index (ABI) significantly increased (0.85 ± 0.15 vs. 0.51 ± 0.11 at baseline; P=0.002). Compared to baseline, the difference in the distribution of Rutherford category and the improvement of walking capacity were statistically significant (P=0.0006, P=0.01, respectively)., Conclusion: This study shows the feasibility of solely endovascular management of severe aortoiliac occlusive disease with a high rate of success and low rate of complications. Significant clinical improvement of patients in long term follow up makes the endovascular approach a viable alternative to open surgery.

The rate of endovascular interventions for iliac occlusive lesions is continuously growing. The evolution of the technology supporting these therapeutic measures improves the results of these interventions. We performed a review of the literature to report and appreciate short- and long-term results of endovascular stenting of iliac artery occlusive lesions. The Medline database was searched to identify all the studies reporting iliac artery stenting for aortoiliac occlusive disease (Trans Atlantic Inter-Society Consensus [TASC] type A, B, C, and D) from January 2006 to July 2012. The outcomes were technical success, long-term primary and secondary patency rates, early mortality, and complications. Technical success was achieved in 91% to 99% of patients as reported in all the analyzed articles. Early mortality was described in 5 studies and ranged from 0.7% to 3.6%. The most common complications were access site hematomas, distal embolization, pseudoaneurysms, and iliac artery ruptures. The complications were most often treated conservatively or using percutaneous techniques. The 5-year primary and secondary patency rates ranged from 63% to 88% and 86% to 93%, respectively; and the 10-year primary patency rates ranged from 68% to 83%. In this article, combined percutaneous endovascular iliac stenting and infrainguinal surgical reconstructions and new techniques in the treatment of iliac stent restenosis are discussed. Iliac stenting is a feasible, safe, and effective method for the treatment of iliac occlusive disease. Initial technical and clinical success rates are high; early mortality and complication rates are low. Long-term patency is comparable with that after bypass surgery.

Purpose: To assess the impact of using inner wall vs. outer wall measurements on stent-graft sizing for endovascular repair of abdominal aortic aneurysm (AAA)., Methods: Preoperative static and electrocardiographically-gated 64-slice computed tomographic angiography (CTA) datasets were acquired on 40 consecutive AAA patients (29 men; mean age 78.9 ± 6 years, range 75-89). On static images, the aortic neck diameters were manually measured twice by 2 readers at 3 clinically relevant levels (supra-, juxta-, and infrarenal). The measurements were obtained from intima-to-intima (inner wall) and from adventitia-to-adventitia (outer wall). Dynamically reconstructed scans were also reviewed in each phase of the cardiac cycle to identify inner and outer minimum/maximum diameters. Using inner and outer wall measurements performed on static images, readers selected the size of a stent-graft that required inner neck diameter measurements and then one that required outer wall diameters. To calculate the relative oversizing, each selected stent-graft size was compared to that obtained using dynamic measurements. Oversizing <4% or >30% was considered inadequate., Results: Mean variations for the inner and outer wall diameters of 9.75% ± 4.01% and 8.66% ± 3.71%, respectively, were recorded on static CTAs; the absolute changes in diameters were 1.82 ± 0.63 mm and 1.91 ± 0.64 mm, respectively. No statistically significant differences were found relative to aortic pulsatility at the 3 levels in the neck for the inner or outer wall diameters. Significant variability was seen between inner (mean 20.8 ± 3.4 mm) vs. outer (mean 23.7 ± 4.3 mm; p < 0.05) wall diameters. Stent-graft sizes significantly changed on the basis of the measurement method and device; for example, using the outer diameter to size a stent-graft that requires an inner diameter reference changed 36% of the selected stent-graft sizes, with ~20% being excessively oversized. Conversely, using the inner diameter to size an outer-diameter-based stent-graft resulted in nearly 40% of the sizes being altered. Based on dynamic measurements, the changes were more dramatic: the oversizing was considered excessive in up to 90% of patients if the measurement method did not match the stent-graft's stipulated reference., Conclusions: These data suggest that stent-graft sizing should follow the manufacturer's recommendations for using inner or outer diameter references based on dynamic patterns (mean value between diastolic and systolic diameters suggested).

Polymeric endoaortic paving (PEAP) may improve endovascular repair of abdominal aortic aneurysms (AAA) since it has the potential to treat patients with complex AAA geometries while reducing the incidence of migration and endoleak. Polycaprolactone (PCL)/polyurethane (PU) blends are proposed as PEAP materials due to their range of mechanical properties, thermoformability, and resistance to biodegradation. In this study, the reduction in AAA wall stress that can be achieved using PEAP was estimated and compared to that resulting from stent-grafts. This was accomplished by mechanically modeling the anisotropic response of PCL/PU blends and implementing these results into finite element model (FEM) simulations. We found that at the maximum diameter of the AAA, the 50/50 and 10/90 PCL/PU blends reduced wall stress by 99 and 98%, respectively, while a stent-graft reduced wall stress by 99%. Our results also show that wall stress reduction increases with increasing PEAP thickness and PCL content in the blend ratio. These results indicate that PEAP can reduce AAA wall stress as effectively as a stent-graft. As such, we propose that PEAP may provide an improved treatment alternative for AAA, since many of the limitations of stent-grafts have the potential to be solved using this approach.