Prevalence of type II endoleak after elective endovascular aneurysm repair with polytetrafluoroethylene- or polyester-based endografts.

OBJECTIVE: Type II endoleak is the most frequent complication after endovascular abdominal aneurysm repair. Polytetrafluoroethylene and polyester (PE) are the two most commonly used graft materials in endovascular aneurysm repair (EVAR) devices. Biological properties of the material might influence the appearance and persistence of type II endoleak (T2EL). Therefore, the aim of this study was to evaluate potential differences in the prevalence of T2EL after EVAR between polytetrafluoroethylene (PTFE) and PE endografts in patients electively treated for an infrarenal abdominal aortic aneurysm. METHODS: A single-center, retrospective, observational study was conducted between January 2011 and January 2022. Preoperative, procedural, and follow-up data were derived from electronic health records. Imaging included computed tomography scans, and/or duplex ultrasound examination. The primary end point was the prevalence of T2EL diagnosed within 1 year after EVAR. Secondary end points included the prevalence of T2EL throughout follow-up, early (≤30 days) and late (>30 days) T2EL, the rate of T2EL disappearance during the follow-up period, the prevalence of type I and III endoleak, and T2EL-related reinterventions. RESULTS: Follow-up was available for 394 patients, 245 in the PE and 149 in the PTFE group. The prevalence of T2EL diagnosed within 1 year after endovascular repair was 11.8% in the PE group and 21.5% in the PTFE group (P = .010). There was no significant difference in early (≤30 days) and late (>30 days) T2EL between groups (P = .270 and P = .311). There was no difference in the freedom from endoleak type II reinterventions between groups (P = .877). CONCLUSIONS: The prevalence of T2EL after elective EVAR is significantly higher with the use of PTFE-based endografts compared with PE-based endografts. This difference is mostly based on T2EL diagnosed after 30 days of follow-up.

One-year follow-up after active aortic aneurysm sac treatment with shape memory polymer devices during endovascular aneurysm repair.

OBJECTIVE: To determine the safety and efficacy of treating abdominal aortic aneurysm (AAA) sacs with polyurethane shape memory polymer (SMP) devices during endovascular aneurysm repair (EVAR), using a technique to fully treat the target lumen after endograft placement (aortic flow volume minus the endograft volume). SMP devices self-expand in the sac to form a porous scaffold that supports thrombosis throughout its structure. METHODS: Two identical prospective, multicenter, single-arm studies were conducted in New Zealand and the Netherlands. The study population was adult candidates for elective EVAR of an infrarenal AAA (diameter of ≥55 mm in men and ≥50 mm in women). Key exclusion criteria were an inability to adequately seal a common iliac artery aneurysm, patent sac feeding vessels of >4 mm, and a target lumen volume of <20 mL or >135 mL. Target lumen volumes were estimated by subtracting endograft volumes from preprocedural imaging-based flow lumen volumes. SMP devices were delivered immediately after endograft deployment via a 6F sheath jailed in a bowed position in the sac. The primary efficacy end point was technical success, defined as filling the actual target lumen volume with fully expanded SMP at the completion of the procedure. Secondary efficacy outcome measures during follow-up were the change in sac volume and diameter, rate of type II endoleak and type I or III endoleaks, and the rate of open repair and related reinterventions, with data collection at 30 days, 6 months, and 1 year (to date). Baseline sac volumes and diameters for change in sac size analyses were determined from 30-day imaging studies. Baseline and follow-up volumes were normalized by subtraction of the endograft volume. RESULTS: Of 34 patients treated with SMP devices and followed per protocol, 33 patients were evaluable at 1 year. Preprocedural aneurysm volume was 181.4 mL (95% confidence interval [CI], 150.7-212.1 mL) and preprocedural aneurysm diameter was 60.8 mm (95% CI, 57.8-63.9 mm). The target lumen volume was 56.3 mL (95% CI, 46.9-65.8 mL). Technical success was 100% and the ratio of SMP fully expanded volume to estimated target lumen volume was 1.4 ± 0.3. Baseline normalized sac volume and diameter were 140.7 mL (95% CI, 126.6-154.9 mL) and 61.0 mm (95% CI, 59.7-62.3 mm). The adjusted mean percentage change in normalized volume at 1 year was -28.8% (95% CI, -35.3 to -22.3%; P < .001). The adjusted mean change in sac diameter at 1 year was -5.9 mm (95% CI, -7.5 to -4.4 mm; P < .001). At 1 year, 81.8% of patients (95% CI, 64.5%-93.0%) achieved a ≥10% decrease in normalized volume and 57.6% of patients (95% CI, 39.2%-74.5%) achieved a ≥5 mm decrease in diameter. No device- or study procedure-related major adverse events occurred through 1 year after the procedure. CONCLUSIONS: Treatment of AAA sacs with SMP devices during EVAR resulted in significant sac volume and diameter regression at 1 year with an acceptable safety profile in this prospective study.

Post hoc analysis of the SuperB and Zilverpass trials for treatment of long and complex superficial femoral artery lesions.

OBJECTIVE: In two randomized controlled trials, the outcomes of endovascular treatment of complex femoropopliteal arterial lesions were compared with bypass surgery and considered a valid alternative treatment. The aim of this study was to compare both endovascular treatment options with the hypothesis that implantation of heparin-bonded self-expanding covered stents (Viabahn [SECS]) or drug-eluting stents (ZilverPTX [DES]) are related to similar clinical outcomes at 1-year follow-up. METHODS: In a post-hoc analysis, the SuperB trial and Zilverpass databases were merged. Patients in the endovascular treatment arms were included, and data was analyzed in an intention-to-treat (ITT) and a per-protocol (PP) fashion. Data included baseline and lesion characteristics, procedural details, and follow-up data. The primary endpoint of this study was primary patency at 1-year follow-up. The secondary endpoints were secondary patency, target lesion revascularization (TLR), limb loss, and all-cause mortality. RESULTS: A total of 176 patients were included; 63 in the SECS arm and 113 in the DES arm. Through 1-year follow-up, there were no significant differences in primary patency (ITT: 63.4% vs 71.1%: P = .183 and PP: 60.8% vs 71.1%; P = .100). Secondary patency rates were not significantly different in the ITT analysis (86.5% vs 95.1%; P = .054), but in the PP analysis, there was a significant difference in favor of the DES group (SECS, 85.6% vs DES, 95.1%; P = .038). There was no significant difference in freedom from TLR between groups (79.6% vs 77.0%; P = .481). No major amputations were performed in the SECS group, and two were performed in the DES group (1.8%). Survival rate was 98.2% in the SECS group, and 91.3% in the DES group after 1-year follow-up (P = .106). Based on diagnosis (intermittent claudication vs chronic limb-threatening ischemia) no differences between patients with intermittent claudication and chronic limb-threatening ischemia were observed in primary patency, secondary patency and freedom from TLR. CONCLUSIONS: Treatment of complex femoropopliteal arterial disease with the heparin-bonded Viabahn endoprosthesis and the Zilver PTX drug-eluting stent are related to similar primary and secondary patency, and TLR rates at 1 year, except for secondary patency in the PP analysis. This study further supports the endovascular treatment of long complex lesions in the femoropopliteal artery.

Upside-Down Gore Excluder as an Endoprosthesis for Aortoiliac Aneurysm Exclusion: A Retrospective Multicenter Study.

OBJECTIVE: The upside-down configuration of a Gore Excluder contralateral leg endoprosthesis has been used to overcome diameter differences in the endovascular treatment of aortoiliac aneurysms. Our goal was not to describe the technique but to study the applicability and safety. MATERIAL AND METHODS: Patients were retrospectively enrolled. The indication and details of the procedure were at the discretion of the treating physicians. A case report form was completed including baseline characteristics, indication for treatment, procedural data, and outcomes during follow-up. RESULTS: A total of 31 subjects were enrolled with a range of indications, including 3 patients treated in the emergency setting (9.7%). In 64.5% (n=20), it was a primary intervention for a common iliac aneurysm (n=10), internal iliac aneurysm (n=4), or abdominal aortic aneurysm (n=6). In 11 subjects (35.5%), treatment was performed after previous aortoiliac interventions, including anastomotic iliac artery aneurysm (n=5), type III endoleak (n=3), and endograft thrombus (n=3). Median follow-up was 13 months (range=1-142 months). During follow-up, 2 patients required an upside-down contralateral leg-related secondary intervention, one for an occlusion and another for a type Ia endoleak. There was no type Ib or III endoleak, and no migration, kinking/stenosis, or conversion to open repair was observed. The aneurysm-related mortality was 3.3% (n=1). CONCLUSION: An upside-down contralateral leg is a valuable technique that can be used to achieve adequate aneurysm exclusion or resolve complications. It is associated with a limited number of complications. CLINICAL IMPACT: This article studies the use of an upside-down iliac endograft. We describe a wide range of indications in which this previously published technique has been applied. In elective and acute settings and as primary and revision intervention an upside-down iliac endograft was performed successfully. Furthermore, follow-up data is presented showing the effectiveness of the technique. Knowledge of this procedure is a valuable addition to the skillset of every interventionalist.

Impact on Hospital Resource Utilization of Endoluminal Bypass Using the Viabahn Endoprosthesis with Heparin Bioactive Surface Compared With Surgical Femoropopliteal Bypass.

OBJECTIVE: To assess the impact of heparin-bonded endoprosthesis compared with femoropopliteal bypass on key hospital resources and revenues up to 1-year follow-up. DESIGN: A 2-arm scenario resource consumption data analysis was modeled based on a multicentre prospective randomized controlled trial. SETTING: Six centers in the Netherlands. PARTICIPANTS: A total of 100 patients were assigned to 2 arms (50 each arm). The first arm evaluated endovascular treatment using the heparin-bonded Viabahn endoprosthesis and the second the femoropopliteal bypass. Resource consumption rates were compared between arms. PRIMARY AND SECONDARY OUTCOMES MEASURES: Resource consumption rates, including hospital stay for bypass procedure, operating room time, type of anesthesia, number of used (endo)grafts, use of different types of bed locations (vascular ward, medium or intensive care), readmission for wound infections, and reinterventions over a period of 12 months. RESULTS: Endovascular repair used fewer hospital resources, with an overall difference of €149.983. Hospital stay was 118 days less (261 vs 379), including 21 fewer days in medium/intensive care (5 vs 26) and 50 fewer operating room hours (100 vs 150). Fewer patients required general anesthesia (31 vs 39), and there were less surgical site infections (3 vs 12). In the surgical bypass group, there were 18 fewer days of hospital stay related to reinterventions (80 vs 62), and the cost of the devices was €309.996, cheaper. The total monetary difference was € 160.013, in favor of the femoropopliteal bypass (€3.200, per patient). CONCLUSIONS: Endovascular repair of the superficial femoral artery reduces the use of valuable hospital resources. Its major limitation is the cost of the devices, which should be balanced against the reduction in peri-procedural morbidity and faster recovery. In the context of shortage of hospital beds, it offers capacity benefits, allowing for the treatment of more patients overall. These benefits may outweigh the fewer reinterventions in the surgical bypass group. REGISTRATION: The SuperB Trial was registered in clinicaltrials.gov; NCT-ID: NCT01220245. CLINICAL IMPACT: Modeling is a useful technique to predict the impact of treatment modalities on hospital resources and revenue. This study uses real-world data from the SuperB Trial to compare two treatment strategies of superficial femoral artery disease, reflecting actual clinical practice and patient outcomes. The analysis focused on direct costs associated with hospital resources and device usage without considering indirect costs or long-term cost-effectiveness. The analysis showed that endovascular repair reduces the use of valuable hospital resources. Its major limitation is device costs, which should be balanced against the reduction in peri-procedural morbidity and faster recovery. In the context of shortage of hospital beds, it offers capacity benefits, allowing for the treatment of more patients overall.

Five-Year Outcomes of the SuperB Trial: A Multicenter Randomized Controlled Trial Comparing Heparin-Bonded Endograft to Surgical Femoropopliteal Bypass.

OBJECTIVE: This study aims to compare the 5-year outcomes of endoluminal bypass (EB) using heparin-bonded self-expanding covered stents versus bypass surgery for extensive femoropopliteal disease, including technical and clinical outcomes and health status. BACKGROUND: The surgical femoropopliteal bypass was the gold standard to treat peripheral arterial disease (PAD) for decades; however, endovascular treatment modalities are now recommended for most femoropopliteal lesions. One-year data of a randomized controlled trial comparing EB with surgical bypass (SB) have shown a faster recovery, less morbidity, and comparable patency rates between the two techniques. To date, long-term randomized controlled data regarding both techniques are lacking. METHODS: Five-year results of a multicenter randomized controlled trial comparing EB with SB in patients with femoropopliteal artery disease were evaluated based on intention-to-treat and per-protocol analyses. RESULTS: At 5-year follow-up, primary, primary-assisted, and secondary patency rates were 36.2%, 52.4%, and 68.1% for EB and 49.4%, 72.2%, and 77.8% for SB, respectively (p=0.608). Freedom from target lesion revascularization (fTLR) was 34.1% for EB and 57.6% for SB (p=0.365). In both groups, the ankle-brachial index, Rutherford classification, and walking distance significantly improved compared with baseline without differences between groups at follow-up. Freedom from major amputation rate was 92.6% in the EB group and 96.2% in the SB group (p=0.361). The 36-Item Short-Form Health Survey showed no significant differences between groups. CONCLUSION: Treatment of extensive femoropopliteal disease with self-expanding covered stents provides comparable clinical-related and health-related questionnaire outcomes when compared with SB through 5 years of follow-up. However, the EB is related to a higher number of reinterventions. CLINICAL IMPACT: This present study is the first to report five-year outcomes comparing an endoluminal (EB) using heparin-bonded self-expanding covered stents with surgical bypass (SB) for long and complex femoropopliteal disease. Although the advantages of treatment with EB are mostly seen in the early period after treatment, the outcomes support the use of EB for this indication and seems to be a valid and safe alternative for bypass surgery. Future trials comparing various endovascular strategies may provide further guidance for the development of an evidence-based treatment algorithm.

Long Term Outcomes of the Gore Excluder Low Permeability Endoprosthesis for the Treatment of Infrarenal Aortic Aneurysms.

OBJECTIVE: This study evaluated the long term outcomes of endovascular aneurysm repair using the Gore Excluder Low Permeability (LP) endoprosthesis across high volume Dutch hospitals. METHODS: A retrospective analysis was conducted of patients treated with the Excluder LP for infrarenal abdominal aortic aneurysm (AAA) in four hospitals between 2004 and 2017. Primary outcomes were overall survival, freedom from re-interventions (overall, inside and outside instructions for use, IFU), and AAA sac dynamics: growth (> 5 mm), stabilisation, and regression (< 5 mm). Secondary outcomes were technical success (device deployment), procedural parameters, and re-interventions. Follow up visits were extracted from patient files, with imaging assessed for complications and AAA diameter. RESULTS: Five hundred and fourteen patients were enrolled, with a median (IQR) follow up of 5.0 (2.9, 6.9) years. Survival rates were 94.0% at one year, 73.0% at five years, and 37.0% at 10 years, with freedom from re-interventions of 89.0%, 79.0%, and 71.0%, respectively. 37.9% were treated outside IFU, leading to significantly more re-interventions over 10 years compared with those treated inside IFU (36.0% vs. 25.0%, respectively; p = .044). The aneurysm sac regressed by 53.5% at one year, 65.8% at five years, and 77.8% at 10 years, and grew by 9.8%, 14.3%, and 22.2%, respectively. Patients with one year sac growth had significantly worse survival (p = .047). Seven patients (1.4%) had a ruptured aneurysm during follow up. Over 15 years, type 1a endoleak occurred in 5.3%, type 1b in 3.1%, type 3 in 1.9%, type 4 in 0.2%, and type 2 in 35.6% of patients. CONCLUSION: This multicentre study of real world endovascular aneurysm repair data using the Gore Excluder LP endoprosthesis demonstrated robust long term survival and re-intervention rates, despite 37.9% of patients being treated outside IFU, with type 4 endoleak being rare. Treatment outside IFU significantly increased re-intervention rates and one year sac growth was associated with statistically significantly worse survival.

The Effect of One Year Aneurysm Sac Dynamics on Five Year Mortality and Continued Aneurysm Sac Evolution.

OBJECTIVE: One year aneurysm sac dynamics after endovascular abdominal aortic aneurysm repair (EVAR) were independently associated with greater risk of all-cause mortality in prior registry studies but were limited in completeness and granularity. This retrospective analysis aimed to study the impact of sac dynamics on survival within the Endurant Stent Graft Global Registry (ENGAGE) with five year follow up. METHODS: A total of 1 263 subjects were enrolled in the ENGAGE Registry between March 2009 and April 2011. One year aneurysm sac changes were calculated from one month post-operative imaging scans and the scan closest to the time of one year follow up. Sac regression was defined as a sac decrease of ≥ 5 mm and sac expansion as aneurysm sac growth ≥ 5 mm. The primary outcome was rate of five year all-cause mortality. Kaplan-Meier estimates for freedom from all-cause mortality were calculated. Multivariable Cox regression was used to determine the association between sac dynamics and all-cause mortality. RESULTS: At one year, 441 of the 949 study participants with appropriate imaging (46%) had abdominal aortic aneurysm sac regression, 462 (49%) remained stable, and 46 (4.8%) had sac expansion. For patients with sac regression, five year all-cause mortality was 20%, compared with 28% for stable sac (p = .007) and 37% for the sac expansion (p = .010) cohorts. After adjustment, sac expansion and stable sac cohorts were associated with greater all-cause mortality (expansion: hazard ratio [HR] 1.8; 95% CI 1.1 - 3.2; p = .032; stable: HR 1.4; 95% CI 1.1 - 1.9; p = .019). CONCLUSION: In the ENGAGE Global Registry, one year rate of sac regression was 46%, and one year sac regression was observed to be associated with greater five year survival, corroborating prior findings utilising data from vascular registries. Sac regression could become the new standard for success after EVAR.

Geometric Analysis of the Gore Excluder Conformable Endoprosthesis in the Infrarenal Aortic Neck: One Year Results of the EXCeL Registry.

OBJECTIVE: The Gore Excluder Conformable Endoprosthesis (CEXC) is designed to treat challenging infrarenal anatomy because of its active angulation control, repositionability, and enhanced conformability. This study evaluated 30 day and one year position and apposition of the CEXC in the infrarenal neck. METHODS: Patients treated with the CEXC between 2018 and 2022 with an available 30 day computed tomography angiogram (CTA) were selected from four hospitals in a prospective registry. Endograft apposition (shortest apposition length [SAL]) and position (shortest fabric distance [SFD]) were assessed on the 30 day and one year CTAs. Maximum infrarenal aortic curvature was compared between the pre- and post-operative CTAs to evaluate conformability of the CEXC. RESULTS: There were 87 patients with a 30 day CTA, and for 56 of these patients the one year CTA was available. Median (interquartile range [IQR]) pre-operative neck length was 22 mm (IQR 15, 32) and infrarenal angulation was 52° (IQR 31, 72). Median SAL was 21.2 mm (IQR 14.0, 29.3) at 30 days for all included patients. The SAL in 13 patients (15%) was < 10 mm at 30 days, and one patient had a SAL of 0 mm and a type Ia endoleak. There was no significant difference in SAL between patients within and outside instructions for use. The SAL significantly increased by 1.1 mm (IQR -2.3, 4.7; p = .042) at one year. The SAL decreased in seven patients (13%), increased in 13 patients (23%), and remained stable in 36 patients (64%). Median SFD was 2.0 mm (IQR 0.5, 3.6) at 30 days, which slightly increased by 0.3 mm (IQR -0.5, 1.8; p = .019) at one year. One patient showed migration (SFD increase ≥ 5 mm). Median endograft tilt was 15.8° (IQR 9.7, 21.4). Pre-operative maximum infrarenal curvature was 36 m-1 (IQR 26, 56) and did not significantly change thereafter. CONCLUSION: In most patients, the CEXC was implanted close to the renal arteries, and sufficient (≥ 10 mm) post-operative apposition was achieved at 30 days, which slightly increased at one year. Post-operative endograft tilt was relatively low, and aortic geometry remained unchanged after implantation of the CEXC, probably due to its high conformability.

Endosutured Aneurysm Repair of Abdominal Aortic Aneurysms with Short Necks Achieves Acceptable Midterm Outcomes-Results from the Peru Registry.

BACKGROUND: The study aims to describe midterm outcomes following treatment of infrarenal abdominal aortic aneurysms (AAAs) with short necks by endosutured aneurysm repair using the Heli-FX EndoAnchor system. METHODS: This is a retrospective study of prospectively collected data from 9 vascular surgery departments between June 2010 and December 2019, including treated AAAs with neck lengths ≤10 mm. The decision for the use of EndoAnchors was made by the treating surgeon or multidisciplinary aortic committee according to each center's practice. There were 2 Groups further assessed according to neck length, A (≥4 and <7 mm) and B (≥7 and ≤10 mm). The main outcomes analyzed were technical success, freedom from type Ia endoleaks (TIaELs), sac size increase, all-cause and aneurysm-related mortality. RESULTS: Seventy-six patients were included in the study, 17 fell into Group A and 59 into Group B. Median follow-up for the cohort was 40.5 (interquartile range 12-61) months. A median of 6 (interquartile range 3) EndoAnchors were deployed in each subject. Technical success was 86.8% for the total group, 82.4% and 88.1% (P = 0.534) for Groups A and B respectively. Six out of 10 (60%) of TIaELs at the completion angiographies showed spontaneous resolution. Cumulative freedom from TIaEL at 3 and 5 years for the total group was 89% and 84% respectively; this was 93% and 74% for Group A and 88% at both intervals in Group B (P = 0.545). In total, there were 7 (9.2%) patients presenting with TIaELs over the entire study period. Two (11.8%) in Group A and 5 (8.5%) in Group B (P = 0.679). There were more patients with sac regression in Group B (Group A = 6-35.3% vs. Group B = 34-57.6%, P = 0.230) with no statistical significance. All-cause mortality was 19 (25%) patients, with no difference (4-23.5% vs. 15-25.4%, P = 0.874) between groups; whereas aneurysm-related mortality occurred in 1 patient from Group A and 3 from Group B. CONCLUSIONS: This study demonstrates reasonable outcomes for patients with short-necked AAAs treated by endosutured aneurysm repair in terms of TIaELs up to 5-year follow-up. EndoAnchor use should be judiciously evaluated in short necks and may be a reasonable option when anatomical constraints are encountered, mainly for those with 7-10 mm neck lengths. Shorter neck length aspects, as indicated by the results from Group A, may be an alternative when no other options are available or feasible.

A systematic review summarizing local vascular characteristics of aneurysm wall to predict for progression and rupture risk of abdominal aortic aneurysms.

OBJECTIVE: At present, the rupture risk prediction of abdominal aortic aneurysms (AAAs) and, hence, the clinical decision making regarding the need for surgery, is determined by the AAA diameter and growth rate. However, these measures provide limited predictive information. In the present study, we have summarized the measures of local vascular characteristics of the aneurysm wall that, independently of AAA size, could predict for AAA progression and rupture. METHODS: We systematically searched PubMed and Web of Science up to September 13, 2021 to identify relevant studies investigating the relationship between local vascular characteristics of the aneurysm wall and AAA growth or rupture in humans. A quality assessment was performed using the ROBINS-I (risk of bias in nonrandomized studies of interventions) tool. All included studies were divided by four types of measures of arterial wall characteristics: metabolism, calcification, intraluminal thrombus, and compliance. RESULTS: A total of 20 studies were included. Metabolism of the aneurysm wall, especially when measured by ultra-small superparamagnetic iron oxide uptake, and calcification were significantly related to AAA growth. A higher intraluminal thrombus volume and thickness had correlated positively with the AAA growth in one study but in another study had correlated negatively. AAA compliance demonstrated no correlation with AAA growth and rupture. The aneurysmal wall characteristics showed no association with AAA rupture. However, the metabolism, measured via ultra-small superparamagnetic iron oxide uptake, but none of the other measures, showed a trend toward a relationship with AAA rupture, although the difference was not statistically significant. CONCLUSIONS: The current measures of aortic wall characteristics have the potential to predict for AAA growth, especially the measures of metabolism and calcification. Evidence regarding AAA rupture is scarce, and, although more work is needed, aortic wall metabolism could potentially be related to AAA rupture. This highlights the role of aortic wall characteristics in the progression of AAA but also has the potential to improve the prediction of AAA growth and rupture.

Mortality analysis of endovascular aneurysm sealing versus endovascular aneurysm repair.

BACKGROUND: Endovascular aneurysm sealing (EVAS), using the Nellix endovascular aneurysm sealing system, has been associated with high reintervention and migration rates. However, prior reports have suggested that EVAS might be related to a lower all-cause mortality compared with endovascular aneurysm repair (EVAR). In the present study, we examined the 5-year all-cause mortality trends after EVAS and EVAR. METHODS: We compared the 333 EVAS patients in the EVAS-1 Nellix U.S. investigational device exemption trial with 16,497 infrarenal EVAR controls from the Vascular Quality Initiative, treated between 2014 and 2016, after applying the exclusion criteria from the investigational device exemption trial (ie, hemodialysis, creatinine >2.0 mg/dL, rupture). As a secondary analysis, we stratified the patients by aneurysm diameter (<5.5 cm and ≥5.5 cm). We calculated propensity scores after adjusting for demographics, comorbidities, and anatomic characteristics and applied inverse probability weighting to compare the risk-adjusted long-term mortality using Kaplan-Meier and Cox regression analyses. RESULTS: After weighting, the EVAS group had experienced similar 5-year mortality compared with the controls from the Vascular Quality Initiative (EVAS vs EVAR, 18% vs 14%; hazard ratio [HR], 1.1; 95% confidence interval [CI], 0.71-1.7; P = .70). The subgroup analysis demonstrated that for patients with an aneurysm diameter of <5.5 cm, EVAS was associated with higher 5-year mortality compared with EVAR (19% vs 11%; HR, 2.4; 95% CI, 1.7-4.7; P = .013). In patients with an aneurysm diameter of ≥5.5 cm, EVAS was associated with lower mortality within the first 2 years (2-year mortality: HR, 0.29; 95% CI, 0.13-0.62; P = .002). However, compared with EVAR, EVAS was associated with higher mortality between 2 and 5 years (HR, 1.9; 95% CI, 1.2-3.0; P = .005), with no mortality difference at 5 years (18% vs 17%; HR, 0.82; 95% CI, 0.4-1.4; P = .46). CONCLUSIONS: Within the overall population, EVAS was associated with similar 5-year mortality compared with EVAR. EVAS was associated with higher mortality for those with small aneurysms (<5.5 cm). For those with larger aneurysms (≥5.5 cm), EVAS was initially associated with lower mortality within the first 2 years, although this advantage was lost thereafter, with higher mortality after 2 years. Future studies are required to evaluate the specific causes of death and to elucidate the potential beneficial mechanism behind sac obliteration that leads to this potential initial survival benefit. This could help guide the development of future grafts with better proximal fixation and sealing that also incorporate sac obliteration.

Systematic Review of the Current In Vitro Experience of the Endovascular Treatment of Juxtarenal Abdominal Aortic Aneurysms by Fenestrated and Parallel Endografting.

OBJECTIVE: To identify and analyze the published in vitro benchtop experiments for the assessment of endovascular techniques used for the treatment of juxtarenal abdominal aortic aneurysms (jAAAs). DATA SOURCES: Scopus, PubMed, and Web of Science. REVIEW METHODS: A systematic literature search was carried out throughout March 2021 following PRISMA guidelines. Two investigators independently performed title and abstract screening to reveal all benchtop testing evaluating the endovascular treatment of jAAA. RESULTS: A total of 19 studies were included, 8 evaluating fenestrated (FEVAR) and 11 parallel grafts (PGs). FEVAR studies used different custom testing apparatus (n=7) or 3D-printed models (n=1) to analyze dislodgement and migration resistance, misalignment consequences and causation, and bridging stents' radial force, flareability, fatigue, and fracture resistance. All PG studies used silicone-based models to analyze optimal oversizing, sealing length, gutter behavior, and possible reduction. Test evaluation in FEVAR in vitro testing was based on pullout force analysis (N=5), photo evaluation (n=1), fluoroscopy (n=1), X-rays (n=4), CT analysis (n=3), macro- and microscopic evaluation (n=4), water permeability (n=1), and fatigue simulator testing (n=1), while it was based on CT analysis in all PG studies adding ECG-gate in one study. The most frequently tested devices were Zenit (Cook) (n=7), Endurant (Medtronic) (n=5), and Excluder (Gore) (n=5) as main grafts, and Advanta V12 (n=14) as the bridging device. CONCLUSIONS: This systematic review presents a broad analysis of the current in vitro methods evaluating the endovascular treatment of jAAA. Fundamental issues have been benchtop tested in both FEVAR and PGs. The analysis of the included studies allowed to recommend an optimal testing design. In vitro testing is a potential tool to further elucidate points of attention hard to investigate in vivo to finally enhance the endovascular treatment outcomes. Future in vitro studies are needed to evaluate the in vitro performance of all indistinctively used devices in the clinical practice.

Computational Fluid Dynamics for the Prediction of Endograft Thrombosis in the Superficial Femoral Artery.

PURPOSE: Contemporary diagnostic modalities, including contrast-enhanced computed tomography (CTA) and duplex ultrasound, have been insufficiently able to predict endograft thrombosis. This study introduces an implementation of image-based computational fluid dynamics (CFD), by exemplification with 4 patients treated with an endograft for occlusive disease of the superficial femoral artery (SFA). The potential of personalized CFD for predicting endograft thrombosis is investigated. MATERIALS AND METHODS: Four patients treated with endografts for an occluded SFA were retrospectively included. CFD simulations, based on CTA and duplex ultrasound, were compared for patients with and without endograft thrombosis to investigate potential flow-related causes of endograft thrombosis. Time-averaged wall shear stress (TAWSS) was computed, which highlights areas of prolonged residence times of coagulation factors in the graft. RESULTS: CFD simulations demonstrated normal TAWSS (>0.4 Pa) in the SFA for cases 1 and 2, but low levels of TAWSS (<0.4 Pa) in cases 3 and 4, respectively. Primary patency was achieved in cases 1 and 2 for over 2 year follow-up. Cases 3 and 4 were complicated by recurrent endograft thrombosis. CONCLUSION: The presence of a low TAWSS was associated with recurrent endograft thrombosis in subjects with otherwise normal anatomic and ultrasound assessment and a good distal run-off.

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

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.

Long-Term Outcomes of the Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) Technique in Patients With Aorto-Iliac Occlusive Disease.

BACKGROUND: The Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) reconstruction is an endovascular technique, developed to reconstruct the aortic bifurcation in the most optimal anatomical and physiological manner. Short-term data were promising, but long-term data are still lacking. The objective was to report the long-term outcomes of CERAB for extensive aorto-iliac occlusive disease and to identify predictors for loss of primary patency. METHODS: Consecutive electively treated patients with CERAB for aorto-iliac occlusive disease in a single hospital were identified and analyzed. Baseline and procedural data and follow-up were collected at 6-weeks, 6 months, 12 months, and annually thereafter. Technical success, procedural, and 30-day complications were evaluated, as well as overall survival. Patency and freedom from target lesion revascularization rates were analyzed using Kaplan Meier curves. Uni- and multivariate analysis were performed to identify possible predictors of failure. RESULTS: One hundred and sixty patients were included (79 male). Indication for treatment was intermittent claudication for 121 patients (75.6%) and 133 patients (83.1%) had a TASC-II D lesion. Technical success was obtained in 95.6% of patients and the 30-day mortality rate was 1.3%. The 5-year primary, primary-assisted, and secondary patency rates were 77.5%, 88.1%, and 95.0%, respectively, with a freedom-from clinically driven target lesion revascularization (CD-TLR) rate of 84.4%. The strongest predictor of loss of primary patency of CERAB was a previous aorto-iliac intervention (odds ratio [OR]=5.36 (95% confidence interval [CI]: 1.30; 22.07), p=0.020). In patients not previously treated in the aorto-iliac tract, 5-year primary, primary assisted, and secondary patency rates were 85.1%, 94.4%, and 96.9%, respectively. At 5-year follow-up, an improved Rutherford was found in 97.9% of patients and the freedom from major amputation rate was 100%. CONCLUSION: The CERAB technique is related to good long-term outcomes, particularly in primary cases. In patients that had prior treatment for aorto-iliac occlusive disease, there were more reinterventions and therefore surveillance should likely be more intense. CLINICAL IMPACT: The Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) reconstruction was designed to improve outcomes of endovascular treatment of extensive aorto-iliac occlusive disease. At 5-year follow-up clinical improvement was found in 97.9% of patients without major amputations. The 5-year overall primary, primary-assisted, and secondary patency rates were 77.5%, 88.1%, and 95.0%, respectively, with a freedom-from clinically driven target lesion revascularization rate of 84.4%. Significantly better patency rates were observed for patients that were never treated before in the target area. The data implicate that CERAB are a valid treatment option for patients with extensive aorto-iliac occlusive disease. For patients previously treated in the target area, other treatment options might be considered, or more intensive follow-up surveillance is warranted.

Renal and Visceral Artery Configuration During the First Year of Follow-Up After Fenestrated Aortic Aneurysm Repair Using the Anaconda Stent-graft: A Prospective Longitudinal Multicenter Study With ECG-Gated CTA Scans.

OBJECTIVE: The performance of fenestrated endovascular aortic aneurysm repair (FEVAR) may be compromised by complications related to the dynamic vascular environment. The aim of this study was to analyze the behavior of FEVAR bridging stent configurations during the cardiac cycle and during follow-up to improve our understanding on treatment durability. DESIGN: Twenty-one patients presenting with complex abdominal aortic aneurysms (AAAs; 9 juxtarenal/6 pararenal/3 paravisceral/1 thoracoabdominal aortic aneurysm type IV), treated with a fenestrated Anaconda (Terumo Aortic, Inchinnan, Scotland, UK) with Advanta V12 bridging stents (Getinge, Merrimack, NH, USA), were prospectively enrolled in a multicenter observational cohort study and underwent electrocardiogram (ECG)-gated computed tomographic angiography (CTA) preoperatively, at discharge, 7-week, and 12-month follow-ups. METHODS: Fenestrated endovascular aortic aneurysm repair stability was assessed considering the following variables: branch angle as the angle between the aorta and the target artery, end-stent angle as the angle between the end of the bridging stent and the native artery downstream from it, curvature and tortuosity index (TI) to describe the bending of the target artery. Body-bridging stent stability was assessed considering bridging stent flare lengths, the distances between the proximal sealing stent-ring and fenestrations and the distance between the fenestration and first apposition in the target artery. RESULTS: Renal branch angles significantly increased after FEVAR toward a perpendicular position (right renal artery from median 60.9°, inter quartile range [IQR]=44.2-84.9° preoperatively to 94.4°, IQR=72.6-99.8°, p=0.001 at 12-month follow-up; left renal artery [LRA], from 63.7°, IQR=55.0-73.0° to 94.3°, IQR=68.2-105.6°, p<0.001), while visceral branch angles did not. The mean dynamic curvature only decreased for the LRA from preoperative (3.0, IQR=2.2-3.8 m-1) to 12-month follow-up (1.9, IQR=1.4-2.6 m-1, p=0.027). The remaining investigated variables did not seem to show any changes over time in this cohort. CONCLUSIONS: Fenestrated endovascular aortic aneurysm repair for complex AAAs using the Anaconda fenestrated stent-graft and balloon-expandable Advanta V12 bridging stents demonstrated stable configurations up to 12-month follow-up, except for increasing renal branch angles toward perpendicular orientation to the aorta, yet without apparent clinical consequences in this cohort. CLINICAL IMPACT: This study provides detailed information on the cardiac-pulsatility-induced (dynamic) and longitudinal geometry deformations of the target arteries and bridging stents after fenestrated endovascular aortic aneurysm repair (FEVAR) up to 12-month follow-up. The configuration demonstrated limited dynamic and longitudinal deformations in terms of branch angle, end-stent angle, curvature, and tortuosity index (TI), except for the increasing renal branch angles that go toward a perpendicular orientation to the aorta. Overall, the results suggest that the investigated FEVAR configurations are stable and durable, though careful consideration of increasing renal branch angles and significant geometry alterations is advised.

Ultrasound Particle Image Velocimetry to Investigate Potential Hemodynamic Causes of Limb Thrombosis After Endovascular Aneurysm Repair With the Anaconda Device.

PURPOSE: To identify potential hemodynamic predictors for limb thrombosis (LT) following endovascular aneurysm repair with the Anaconda endograft in a patient-specific phantom. MATERIALS AND METHODS: A thin-walled flow phantom, based on a patient's aortic anatomy and treated with an Anaconda endograft, that presented with a left-sided LT was fabricated. Contrast-enhanced ultrasound particle image velocimetry was performed to quantify time-resolved velocity fields. Measurements were performed in the same phantom with and without the Anaconda endograft, to investigate the impact of the endograft on the local flow fields. Hemodynamic parameters, namely vector complexity (VC) and residence time (RT), were calculated for both iliac arteries. RESULTS: In both limbs, the vector fields were mostly unidirectional during the peak systolic and end-systolic velocity phases before and after endograft placement. Local vortical structures and complex flow fields were observed at the diastolic and transitional flow phases. The average VC was higher (0.11) in the phantom with endograft, compared to the phantom without endograft (0.05). Notably, in both left and right iliac arteries, the anterior wall regions corresponded to a 2- and 4-fold increase in VC in the phantom with endograft, respectively. RT simulations showed values of 1.3 to 6 seconds in the phantom without endograft. A higher RT (up to 25 seconds) was observed in the phantom with endograft, in which the left iliac artery, with LT in follow-up, showed 2 fluid stasis regions. CONCLUSION: This in vitro study shows that unfavorable hemodynamics were present mostly in the limb that thrombosed during follow-up, with the highest VC and longest RT. These parameters might be valuable in predicting the occurrence of LT in the future. CLINICAL IMPACT: This in-vitro study aimed to identify potential hemodynamic predictors for limb thrombosis following EVAR using ultrasound particle image velocimetry (echoPIV) technique. It was shown that unfavorable hemodynamic norms were present mostly in the thrombosed limb. Owing to the in-vivo feasibility of the echoPIV, future efforts should focus on the evaluation of these hemodynamic norms in clinical trials. Thereafter, using echoPIV as a bedside technique in hospitals becomes more promising. Performing echoPIV in pre-op phase may provide valuable insights for surgeons to enhance treatment planning. EchoPIV is also applicable for follow-up sessions to evaluate treatment progress and avoid/predict complications.

European Expert Opinion on Infrarenal Sealing Zone Definition and Management in Endovascular Aortic Repair Patients: A Delphi Consensus.

PURPOSE: The purpose of the study was to provide a consensus definition of the infrarenal sealing zone and develop an algorithm to determine when and if adjunctive procedure(s) or reintervention should be considered in managing patients undergoing endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysm (AAA). METHODS: A European Advisory Board (AB), made up of 11 vascular surgeons with expertise in EVAR for AAA, was assembled to share their opinion regarding the definition of preoperative and postoperative infrarenal sealing zone. Information on their current clinical practice and level of agreement on proposed reintervention paths was used to develop an algorithm. The process included 2 virtual meetings and 2 rounds of online surveys completed by the AB (Delphi method). Consensus was defined as reached when ≥ 8 of 11 (73%) respondents agreed or were neutral. RESULTS: The AB reached complete consensus on definitions and measurement of the pre-EVAR target anticipated sealing zone (TASZ) and the post-EVAR real achieved sealing zone (RASZ), namely, the shortest length between the proximal and distal reference points as defined by the AB, in case of patients with challenging anatomies. Also, agreement was achieved on a list of 4 anatomic parameters and 3 prosthesis-/procedure-related parameters, considered to have the most significant impact on preoperative and postoperative sealing zones. Furthermore, the agreement was reached that in the presence of visible neck-related complications, both adjunctive procedure(s) and reintervention should be contemplated (100% consensus). In addition, adjunctive procedure(s) or reintervention can be considered in the following cases (% consensus): insufficient sealing zone on completion imaging (91%) or on the first postoperative computed tomography (CT) scan (91%), suboptimal sealing zone on completion imaging (73%) or postoperative CT scan (82%), and negative evolution of the actual sealing zone over time (91%), even in the absence of visible complications. CONCLUSIONS: AB members agreed on definitions of the pre- and post-EVAR infrarenal sealing zone, as well as factors of influence. Furthermore, a clinical decision algorithm was proposed to determine the timing and necessity of adjunctive procedure(s) and reinterventions.

A systematic review of anatomic predictors of abdominal aortic aneurysm remodeling after endovascular repair.

OBJECTIVE: The long-term outcomes after endovascular abdominal aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) have been inferior to those after open surgical repair with regard to reinterventions and late mortality. AAA sac remodeling after EVAR has been associated with endoleaks, reinterventions, and mortality. Therefore, knowledge of the predictors of AAA sac remodeling could indirectly give insight into the long-term EVAR outcomes. In the present review, we aimed to provide an overview of the evidence for anatomic predictors of positive and negative AAA sac remodeling after EVAR. METHODS: A systematic literature review and analysis were conducted in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) and Cochrane guidelines. The PubMed and Scopus databases were searched using terms of AAA sac growth, shrinkage, and remodeling. Eligible studies were identified, and only those studies that had included currently used endografts were included. RESULTS: A total of 19 studies that had reported on a total of 27 anatomic parameters of the aortoiliac anatomy were included. Only 4 parameters had been investigated by more than five studies, 7 parameters were investigated by three to five studies, 7 parameters were investigated by two studies, and 9 parameters were investigated by one study. For the presence of neck thrombus, three of four studies had reported similar results, indicating that the presence of neck thrombus might predict for less AAA sac shrinkage. AAA thrombus, the total AAA volume, the flow-lumen volume, aortic calcification, and the number of hostile neck parameters were only investigated by two to three studies. However, these parameters seemed promising for the prediction of sac remodeling. For hostile neck anatomy, neck length, infrarenal neck angulation, and patency of the inferior mesenteric artery, no significant association with any category of AAA sac remodeling was found. CONCLUSIONS: The present review demonstrates neck thrombus, AAA thrombus, number of hostile neck parameters, total AAA volume, AAA flow-lumen volume, and aortic calcification as important anatomic features that are likely to play a role in AAA remodeling after endovascular repair and should be further explored using advanced imaging techniques. We also found that strong, consistent evidence regarding the anatomic predictors of AAA sac remodeling after EVAR is lacking. Therefore, further research with large patient groups for a broad range of predictors of AAA sac change after EVAR is needed to complement the current gap in the evidence.