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.

Lesion Eccentricity Plays a Key Role in Determining the Pressure Gradient of Serial Stenotic Lesions: Results from a Computational Hemodynamics Study

PURPOSE

In arterial disease, the presence of two or more serial stenotic lesions is common. For mild lesions, it is difficult to predict whether their combined effect is hemodynamically significant. This study assessed the hemodynamic significance of idealized serial stenotic lesions by simulating their hemodynamic interaction in a computational flow model.

MATERIALS AND METHODS

Flow was simulated with SimVascular software in 34 serial lesions, using moderate (15 mL/s) and high (30 mL/s) flow rates. Combinations of one concentric and two eccentric lesions, all 50% area reduction, were designed with variations in interstenotic distance and in relative direction of eccentricity. Fluid and fluid-structure simulations were performed to quantify the combined pressure gradient.

RESULTS

At a moderate flow rate, the combined pressure gradient of two lesions ranged from 3.8 to 7.7 mmHg, which increased to a range of 12.5-24.3 mmHg for a high flow rate. Eccentricity caused an up to two-fold increase in pressure gradient relative to concentric lesions. At a high flow rate, the combined pressure gradient for serial eccentric lesions often exceeded the sum of the individual lesions. The relative direction of eccentricity altered the pressure gradient by 15-25%. The impact of flow pulsatility and wall deformability was minor.

CONCLUSION

This flow simulation study revealed that lesion eccentricity is an adverse factor in the hemodynamic significance of isolated stenotic lesions and in serial stenotic lesions. Two 50% lesions that are individually non-significant can combine more often than thought to hemodynamic significance in hyperemic conditions.

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 angiography (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-operative 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 1 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 1 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 acquired 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.

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.

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.

Endosutured aneurysm repair (ESAR) of abdominal aortic aneurysms with short necks achieves acceptable mid-term outcomes - results from the PERU registry

INTRODUCTION

The study aims to describe midterm outcomes following treatment of infrarenal abdominal aortic aneurysms (AAAs) with short necks by endosutured aneurysm repair (ESAR) using the Heli-FX EndoAnchor system.

METHODS

This is a retrospective study of prospectively collected data from nine vascular surgery departments between June 2010 - December 2019, including treated AAAs with neck lengths ≤ 10mm. The decision for the use of EndoAnchors was made by the treating surgeon or multidisciplinary aortic committee according to each centre's practice. There were two subgroups further assessed according to neck length, A (≥4 and < 7mm) and B (≥7 and ≤10mm). The main outcomes analysed were technical success, freedom from type Ia endoleaks (TIaEL), sac size increase, all-cause (ACM) and aneurysm related mortality (ARM).

RESULTS

76 patients were included in the study, 17 fell into Subgroup A and 59 into subgroup B. Median follow-up for the cohort was 40.5 (IQR 12-61) months. A median of 6 (IQR 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 subgroups A and B respectively. Six out of ten (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 subgroup A and 88% at both intervals in subgroup B (p=0.545). In total, there were 7 (9.2%) patients presenting with type Ia endoleaks over the entire study period. Two (11.8%) in subgroup A and 5 (8.5%) in subgroup B (p=0.679). There were more patients with sac regression in subgroup B (subgroup A=6 - 35.3% versus subgroup B=34 - 57.6%, p=0.230) with no statistical significance. ACM was 19 (25%) patients, with no difference (4 - 23.5% versus 15 - 25.4%, p=0.874) between subgroups; whereas ARM occurred in one patient from subgroup A and 3 from subgroup B.

CONCLUSIONS

This study demonstrates reasonable outcomes for patients with short-necked AAAs treated by ESAR in terms of type Ia endoleaks 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 7-10mm 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.

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.

Dual-Pathway Inhibition with Rivaroxaban and Low-Dose Aspirin Does Not Alter Immune Cell Responsiveness and Distribution in Patients with Coronary Artery Disease

INTRODUCTION

Cardiovascular diseases (CVD) are the leading cause of death globally. Inflammation is an important driver of CVD where tissue damage may lead to the formation of deadly thrombi. Therefore, antithrombotic drugs, such as platelet inhibitors, are crucial for secondary risk prevention in coronary artery disease (CAD) and peripheral artery disease (PAD). For severe forms of the disease, dual-pathway inhibition (DPI) where low-dose aspirin is combined with rivaroxaban has shown improved efficacy in reducing cardiovascular mortality.

METHODS

Given this greater improvement in mortality, and the importance of inflammation in driving atherosclerosis, the potential for off-target inflammation-lowering effects of these drugs was evaluated by looking at the change in immune cell distribution and responsiveness to ex vivo lipopolysaccharide (LPS) stimulation after 3 months of DPI in patients with CAD.

RESULTS

We observed no changes in whole blood or peripheral blood mononuclear cell (PBMC) immune cell responsiveness to LPS after 3 months of DPI. Additionally, we did not observe any changes in the distribution of total white blood cells, monocytes, neutrophils, lymphocytes, or platelets during the study course. Signs of systemic inflammation were studied using Olink proteomics in 33 patients with PAD after 3 months of DPI. No changes were observed in any of the inflammatory proteins measured after the treatment period, suggesting that the state of chronic inflammation was not altered in these subjects.

CONCLUSION

Three months of DPI does not result in any meaningful change in immune cell responsiveness and distribution in patients with CAD or PAD.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT05210725.

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.

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.

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.

FORWARD Study of GORE VIABAHN Balloon-Expandable Endoprostheses and Bare Metal Stents in the United States, European Union, United Kingdom, Australia, and New Zealand When Placed to Treat Complex Iliac Occlusive Disease: Protocol for a Randomized Superiority Trial

BACKGROUND

The recommendations for the use of and selection of covered stent grafts in patients with aortoiliac occlusive disease are limited.

OBJECTIVE

The GORE VBX FORWARD clinical study aims to demonstrate the superiority of the GORE VIABAHN VBX Balloon Expandable Endoprosthesis (VBX device) for primary patency when compared to bare metal stenting (BMS) for the treatment of complex iliac artery occlusive disease.

METHODS

A prospective, multicenter, randomized control study in the United States, European Union, United Kingdom, Australia, and New Zealand will enroll patients with symptomatic, complex iliac artery occlusive disease. In this study, iliac artery occlusive disease is defined as a unilateral or bilateral disease with single or multiple lesions (with >50% stenosis or chronic total occlusion) each between 4 and 11 cm in length. In an attempt to more closely match real-world practices, patients with minor tissue loss (Rutherford class 5) and patients requiring hemodialysis will be included. Baseline aortoiliac angiography will be performed to assess target lesion characteristics and determine final patient eligibility. Once the patient is confirmed and guidewires are in place across the target lesions, the patient will be randomized in a 1:1 format to treatment with either the VBX device or a BMS. The BMS can be balloon- or self-expanding and must be approved for the iliac artery occlusive disease indication. Patients, the independent core laboratory reviewers, and Clinical Events Committee members will be blinded from the assigned treatment. Dual antithrombotic medical therapy is required through a minimum of 3 months post procedure. The primary end point is 12‑month primary patency and will be adjudicated by an independent imaging core laboratory and Clinical Events Committee. Key secondary end points will be tested for superiority and include technical, acute procedural, and clinical success; changes in Ankle-brachial index; patient quality of life; primary patency; freedom from restenosis; primary-assisted patency; secondary patency; freedom from target lesion revascularizations; cumulative reintervention rate; amputation-free survival; survival; and change in Rutherford category. Study follow-up will continue through 5 years.

RESULTS

Outcomes will be reported following study completion. Enrollment is anticipated to start in October 2023.

CONCLUSIONS

The results of this study will provide definitive, level 1 clinical evidence to clinicians on the optimal choice of stent device to use for the treatment of complex iliac artery occlusive disease. The FORWARD study is powered for superiority and includes only complex, unilateral, or bilateral lesions involving the common or external iliac arteries. This study is a multidisciplinary endeavor involving vascular surgery, interventional cardiology, and interventional radiology across multiple countries with a blinded core laboratory review of end points in hopes that the outcomes will be widely accepted and incorporated into practice guidelines for optimal treatment of patients with complex iliac artery occlusive disease.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05811364; https://clinicaltrials.gov/study/NCT05811364.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/51480.

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.

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.

The Use of Autologous Subcutaneous Fat Tissue to Embolize an Infected Iliac Artery Pseudoaneurysm

We describe a patient with a fistula between small bowel and a polyester patch of the common iliac artery. After emergency treatment with an endograft, the patch was replaced by a venous patch. Within 3-week a symptomatic pseudoaneurysm developed. It was decided to embolize the pseudoaneurysm using autologous subcutaneous fat, followed by a femoro-femoral crossover bypass using an allograft. Using this technique, the pseudoaneurysm was successfully excluded. This case shows that subcutaneous fat tissue can be used as an autologous embolic material, also in larger vessel pathology and in cases of ongoing infection, where regular embolization material cannot be used.

Five-Year Outcomes after Paclitaxel Drug-Coated Balloon Treatment of Femoropopliteal Lesions in Diabetic and Chronic Limb-Threatening Ischemia Cohorts: IN.PACT Global Study Post Hoc Analysis

PURPOSE

To summarize the 5-year outcomes of drug-coated balloon (DCB) for the treatment of femoropopliteal lesions in patients with diabetes mellitus (DM) or chronic limb-threatening ischemia (CLTI) compared to non-DM and intermittent claudication (IC).

METHODS

The IN.PACT Global study was a real-world prospective, multicenter, international, single-arm study that enrolled 1535 participants. Post hoc analyses were conducted for participants with DM (n = 560) versus non-DM (n = 842) and CLTI (n = 156) versus IC (n = 1246). Assessments included freedom from clinically driven target lesion revascularization (CD-TLR) through 60 months, a composite safety outcome (freedom from device- and procedure-related death through 30 days, and freedom from major target limb amputation and freedom from CD-target vessel revascularization within 60 months), and major adverse events (MAEs).

RESULTS

Kaplan-Meier estimates of 60-month freedom from CD-TLR were 67.7% and 70.5% (p = 0.25) in the DM and non-DM cohorts; and 60.7% and 70.5% (p = 0.006) in the CLTI and IC cohorts. The Kaplan-Meier 60-month composite safety outcomes were 65.1% DM versus 68.9% non-DM (p = 0.12); 53.2% CLTI versus 69.1% IC (p < 0.001). Between DM and non-DM, MAE rates were not significantly different through 60 months except for all-cause mortality which was higher in DM (23.8% versus 16.6%; p < 0.001). Participants with CLTI had a higher cumulative incidence of major target limb amputation (6.8% versus 1.1%; p < 0.001) and all-cause mortality (37.4% versus 17.4%; p < 0.001) through 60 months compared to IC.

CONCLUSIONS

In this real-world study, 5-year reintervention rates following DCB angioplasty were similar between DM and non-DM, but mortality rates were expectedly higher in patients with DM. Reintervention, mortality, and amputation rates were all higher in CLTI patients compared to IC, which is consistent with the known frailty of this patient population.

LEVEL OF EVIDENCE

Level 3, Non-randomized controlled cohort/follow-up study.

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.

Evaluation of Electrocardiogram-Gated Computed Tomography Angiography to Quantify Changes in Geometry and Dynamic Behavior during the Cardiac Cycle of the Nellix Endovascular Sealing System

Background

The Nellix endovascular sealing system (EVAS) was a unique concept with regard to its sealing concept that failed, related to high migration rates. We investigated the changes in aortoiliac morphology during the cardiac cycle before and after EVAS using electrocardiography (ECG)-gated CT.

Methods

Eight patients scheduled for EVAS were prospectively enrolled. ECG-gated CT scans were made pre- and postoperatively. Measurements were performed in the mid-systolic and mid-diastolic phases. Endpoints were changes in infrarenal aortoiliac morphology postoperatively compared to preoperatively and their changes in the cardiac cycle.

Results

Both pre- and postoperatively, there were no changes during the cardiac cycle. EVAS caused an increase in neck diameter and surface in both phases (p < 0.001). EVAS increased the luminal AAA volume (p < 0.001), with a decrease in thrombus volume (p < 0.001) in both phases and an increase in total volume (p < 0.001) in the systolic phase. During follow-up, one patient presented with >5 mm migration. There were no differences in the movements of this patient compared to the remaining patients.

Conclusion

The cardiac cycle had a very limited effect on the aortoiliac dynamics before and after EVAS and, therefore, there is probably not a role for ECG-gated CT in enhanced surveillance programs. EVAS itself has a significant impact on anatomy, particularly the neck diameter, length, and volumes of the AAA.

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.

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.

Revascularization Strategies for Patients With Femoropopliteal Peripheral Artery Disease

BACKGROUND

No adequately powered studies exist to compare major clinical outcomes after endovascular therapy (EVT) with stent implantation vs bypass surgery (BSx) for symptomatic femoropopliteal peripheral artery disease.

OBJECTIVES

This study sought to perform a pooled analysis of individual patient data from all randomized controlled trials comparing EVT vs BSx.

METHODS

Principal investigators of 5 of 6 available randomized controlled trials agreed to pool individual patient data. The primary endpoint was major adverse limb events, a composite of all-cause death, major amputation, or target limb reintervention. Secondary endpoints included amputation-free survival, individual major adverse limb event components, and primary patency. Early complications were bleeding, infection, or all-cause death within 30 days.

RESULTS

A total of 639 patients were analyzed with a mean age of 68.1 ± 9.1 years and 29.0% women. Baseline characteristics were comparable between groups. At 2 years, there were no significant differences between patients who received EVT and those who received BSx regarding major adverse limb events (40.1% vs 36.4%; log-rank P = 0.447; adjusted HR [aHR]: 1.04; 95% CI: 0.80-1.36), amputation-free survival (88.1% vs 90.0%; log-rank P = 0.455; aHR for death or amputation: 1.04; 95% CI: 0.63-1.71) and the other secondary endpoints except for primary patency, which was lower in patients who received EVT vs those who received BSx (51.2% vs 61.3%; log-rank P = 0.024; aHR for loss of primary patency: 1.31; 95% CI: 1.02-1.69). EVT was associated with significantly lower rates of early complications (6.8% vs 22.6%; P < 0.001) and shorter hospital stay (3.1 ± 4.2 days vs 7.4 ± 4.9 days; P < 0.001).

CONCLUSIONS

These findings further support the efficacy and safety of EVT as an alternative to BSx in patients with symptomatic femoropopliteal peripheral artery disease.

The Effect of EndoAnchors on Aneurysm Sac Regression for Patients Treated With Infrarenal Endovascular Repair With Hostile Neck Anatomies: A Propensity Scored Analysis

PURPOSE

To analyze sac evolution patterns in matched patients with hostile neck anatomy (HNA) treated with standard endovascular aneurysm repair (sEVAR) and endosutured aneurysm repair (ESAR).

METHODS

Observational retrospective study using prospectively collected data between June 2010 and December 2019. ESAR group data were extracted from the primary arm of the PERU registry with an assigned identifier (NCT04100499) at 8 centers and those from the sEVAR came from 4 centers. Suitability for inclusion required: no proximal endograft adjuncts (besides EndoAnchor use), ≤15 mm neck length and minimum of 12-months follow-up imaging. Bubble-shaped neck (noncylindrical short neck with discontinuous seal) aspect was analyzed. Both groups were analyzed using propensity score matching (PSM) for aortic neck length, width, angulation, and device fixation type. Main outcome assessed was sac evolution patterns (sac expansion and regression were defined as >5mm increase or decrease, of the maximum sac diameter respectively; all AAAs within this ±5 mm range in diameter change were considered stable) and secondary outcomes were type-Ia endoleaks; other endoleaks and mortality. A power analysis calculation >80% was confirmed for sac regression evaluation.

RESULTS

After exclusions, PSM resulted in 96 ESAR and 96 sEVAR patients. Mean imaging follow-up (months) was 44.4±21.3 versus 43.0±19.6 (p=0.643), respectively. The overall number of patients achieving sac regression was higher in the ESAR group (n=57, 59.4% vs n=31, 32.3%; p<0.001) and the cumulative sac regression achieved at 5 years was 65% versus 38% (p=0.003) in favor of the ESAR group. There were no statistically significant differences in type-Ia endoleak and/or other endoleaks. Univariate analysis for sac regression patients in the sEVAR and ESAR group individually showed the bubble-shape neck as a predictor of sac regression failure. There were no statistical differences in overall and aneurysm-related mortality.

CONCLUSION

Endosutured aneurysm repair provided improved rates of sac regression for patients with AAA and HNA when compared with sEVAR at midterm and up to 5 years, despite similar rates of type-Ia endoleaks, and the need to consider some important limitations. The presence of bubble-shaped neck was a predictor of sac regression failure for both groups equally.

CLINICAL IMPACT

The use of EndoAnchors aids and improves EVAR treatment in hostile neck anatomies by an increased rate of sac regression when compared to EVAR treatment alone in up to 5 year analysis. Moreover, a trend to reduced number of type Ia endoleaks is also achieved, although not significant in the present study. This data, adds to current and growing evidence on the usefulness of EndoAnchors for AAA endovascular treatment.

Dual pathway inhibition as compared to acetylsalicylic acid monotherapy in relation to endothelial function in peripheral artery disease, a phase IV clinical trial

Objective

Dual pathway inhibition (DPI) by combining acetylsalicylic acid (ASA) with low-dose rivaroxaban has been shown to reduce cardiovascular events in patients with peripheral arterial disease (PAD) when compared to ASA monotherapy. A potential explanation is that inhibition of factor Xa improves endothelial function through crosstalk between coagulation and inflammatory pathways, subsequently attenuating the occurrence of cardiovascular events. We hypothesize that the addition of rivaroxaban to ASA in PAD patients leads to improved endothelial function.

Design

An investigator-initiated, multicentre trial investigating the effect of DPI on endothelial function.

Methods

Patients, diagnosed with PAD, were enrolled in two cohorts: cohort A (Rutherford I-III) and cohort B (Rutherford IV-VI). Participants received ASA monotherapy for a 4-weeks run-in period, followed by 12 weeks of DPI. Macro- and microvascular endothelial dysfunction were studied by measuring carotid artery reactivity upon sympathetic stimulus and by measuring plasma endothelin-1 concentrations, respectively. All measurements were performed during the use of ASA (baseline) and after 12 weeks of DPI.

Results

159 PAD patients (111 cohort A, 48 cohort B) were enrolled. Twenty patients discontinued study drugs early. Carotid artery constriction upon sympathetic stimulation at baseline (ASA) and after 12 weeks of DPI was similar in the total group, 22.0 vs. 22.7% (p = 1.000), and in the subgroups (Cohort A 22.6 vs. 23.7%, p = 1.000; cohort B 20.5 vs. 20.5%, p = 1.000), respectively. The mean concentration of plasma endothelin-1 at baseline and after 12 weeks of DPI did not differ, 1.70 ± 0.5 vs. 1.66 ± 0.64 pmol/L (p = 0.440) in the total group, 1.69 ± 0.59 vs. 1.62 ± 0.55 pmol/L in cohort A (p = 0.202), and 1.73 ± 0.53 vs. 1.77 ± 0.82 pmol/L in cohort B (p = 0.682), respectively.

Conclusion

Macro- and microvascular endothelial dysfunction, as reflected by carotid artery reactivity and plasma endothelin-1 concentrations, are not influenced in PAD patients by addition of low-dose rivaroxaban to ASA monotherapy for 12 weeks.

Trial registration

https://clinicaltrials.gov/ct2/show/NCT04218656.

Antithrombotic Therapy for Symptomatic Peripheral Arterial Disease: A Systematic Review and Network Meta-Analysis

Background

High-quality evidence from trials directly comparing single antiplatelet therapies in symptomatic peripheral arterial disease (PAD) to dual antiplatelet therapies or acetylsalicylic acid (ASA) plus low-dose rivaroxaban is lacking. Therefore, we conducted a network meta-analysis on the effectiveness of all antithrombotic regimens studied in PAD.

Methods

A systematic search was conducted to identify randomized controlled trials. The primary endpoints were major adverse cardiovascular events (MACE) and major bleedings. Secondary endpoints were major adverse limb events (MALE) and acute limb ischaemia (ALI). For each outcome, a frequentist network meta-analysis was used to compare relative risks (RRs) between medication and ASA. ASA was the universal comparator since a majority of studies used ASA as in the reference group.

Results

Twenty-four randomized controlled trials were identified including 48,759 patients. With regard to reducing MACE, clopidogrel [RR 0.78, 95% confidence interval (CI) 0.66–0.93], ticagrelor (RR 0.79, 95% CI 0.65–0.97), ASA plus ticagrelor (RR 0.79, 95% CI 0.64–0.97), and ASA plus low-dose rivaroxaban (RR 0.84, 95% CI 0.76–0.93) were more effective than ASA, and equally effective to one another. As compared to ASA, major bleedings occurred more frequently with vitamin K antagonists, rivaroxaban, ASA plus vitamin K antagonists, and ASA plus low-dose rivaroxaban. All regimens were similar to ASA concerning MALE, while ASA plus low-dose rivaroxaban was more effective in preventing ALI (RR 0.67, 95% CI 0.55–0.80). Subgroup analysis in patients undergoing peripheral revascularization revealed that ≥ 3 months after intervention, evidence of benefit regarding clopidogrel, ticagrelor, and ASA plus ticagrelor was lacking, while ASA plus low-dose rivaroxaban was more effective in preventing MACE (RR 0.87, 95% CI 0.78–0.97) and MALE (RR 0.89, 95% CI 0.81–0.97) compared to ASA. ASA plus clopidogrel was not superior to ASA in preventing MACE ≥ 3 months after revascularization. Evidence regarding antithrombotic treatment strategies within 3 months after a peripheral intervention was lacking.

Conclusion

Clopidogrel, ticagrelor, ASA plus ticagrelor, and ASA plus low-dose rivaroxaban are superior to ASA monotherapy and equally effective to one another in preventing MACE in PAD. Of these four therapies, only ASA plus low-dose rivaroxaban provides a higher risk of major bleedings. More than 3 months after peripheral vascular intervention, ASA plus low-dose rivaroxaban is superior in preventing MACE and MALE compared to ASA but again at the cost of a higher risk of bleeding, while other treatment regimens show non-superiority. Based on the current evidence, clopidogrel may be considered the antithrombotic therapy of choice for most PAD patients, while in patients who underwent a peripheral vascular intervention, ASA plus low-dose rivaroxaban could be considered for the long-term (> 3 months) prevention of MACE and MALE.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40265-022-01756-6.

Blood Flow Quantification with High-Frame-Rate, Contrast-Enhanced Ultrasound Velocimetry in Stented Aortoiliac Arteries: In Vivo Feasibility

Local flow patterns influence stent patency, while blood flow quantification in stents is challenging. The aim of this study was to investigate the feasibility of 2-D blood flow quantification using high-frame-rate, contrast-enhanced ultrasound (HFR-CEUS) and particle image velocimetry (PIV), or echoPIV, in patients with aortoiliac stents. HFR-CEUS measurements were performed at 129 locations in 62 patients. Two-dimensional blood flow velocity fields were obtained using echoPIV. Visual inspection was performed by five observers to evaluate feasibility. The contrast-to-background ratio and average vector correlation were calculated and compared between stented and native vessel segments. Flow quantification with echoPIV was feasible in 128 of 129 locations (99%), with optimal quantification in 40 of 129 locations (31%). Partial quantification was achieved in 88 of 129 locations (68%), where one or multiple limiting issues occurred (not related to the stent) including loss of correlation during systole (57/129), short vessel segments (20/129), loss of contrast during diastole (20/129) and shadow regions (20/129). The contrast-to-background ratio and vector correlation were lower downstream in the imaged blood vessel, independent of the location of the stent. In conclusion, echoPIV was feasible in stents placed in the aortoiliac region, and the stents did not adversely affect flow tracking.

High-frame-rate contrast-enhanced ultrasound particle image velocimetry in patients with a stented superficial femoral artery: a feasibility study

Background

Local blood flow affects vascular disease and outcomes of endovascular treatment, but quantifying it is challenging, especially inside stents. We assessed the feasibility of blood flow quantification in native and stented femoral arteries, using high-frame-rate (HFR) contrast-enhanced ultrasound (CEUS) particle image velocimetry (PIV), also known as echoPIV.

Methods

Twenty-one patients with peripheral arterial disease, recently treated with a stent in the femoral artery, were included. HFR CEUS measurements were performed in the native femoral artery and at the inflow and outflow of the stent. Two-dimensional blood flow was quantified through PIV analysis. EchoPIV recordings were visually assessed by five observers and categorised as optimal, partial, or unfeasible. To evaluate image quality and tracking performance, contrast-to-tissue ratio (CTR) and vector correlation were calculated, respectively.

Results

Fifty-eight locations were measured and blood flow quantification was established in 49 of them (84%). Results were optimal for 17/58 recordings (29%) and partial for 32 recordings (55%) due to loss of correlation (5/32; 16%), short vessel segment (8/32; 25%), loss of contrast (14/32; 44%), and/or shadows (18/32; 56%). In the remaining 9/58 measurements (16%) no meaningful flow information was visualised. Overall, CTR and vector correlation were lower during diastole. CTR and vector correlation were not different between stented and native vessel segments, except for a higher native CTR at the inflow during systole (p = 0.037).

Conclusions

Blood flow quantification is feasible in untreated and stented femoral arteries using echoPIV. Limitations remain, however, none of them related to the presence of the stent.

Trial registration

ClinicalTrials.gov, NCT04934501 (retrospectively registered).

Supplementary Information

The online version contains supplementary material available at 10.1186/s41747-022-00278-w.

Multicenter Experience of Upper Extremity Access in Complex Endovascular Aortic Aneurysm Repair

PURPOSE

Upper extremity access (UEA) for antegrade cannulation of aortic side branches is a relevant part of endovascular treatment of complex aortic aneurysms and can be achieved using several techniques, sites and sides. The purpose of this study was to evaluate different UEA strategies in a multicenter registry of complex endovascular aortic aneurysm repair (EVAR).

METHODS

In six aortic centers in the Netherlands, all endovascular aortic procedures from 2006 to 2019 were retrospectively reviewed. Patients who received upper extremity access during complex EVAR were included. Primary outcome was a composite endpoint of any access complication, excluding minor hematomas. Secondary outcomes were access characteristics, access complications considered individually, access reinterventions and incidence of ischemic cerebrovascular events.

RESULTS

417 patients underwent 437 UEA for 303 fenestrated/branched EVARs, and 114 chimney EVARs. Twenty patients had bilateral, 295 left-sided, and 102 right-sided UEA. 413 approaches were performed surgically and 24 percutaneously. Distal brachial access was used in 89 cases, medial brachial in 149, proximal brachial in 140 and axillary access in 59 cases. No significant differences regarding the composite endpoint of access complications were seen (DBA 11.3% vs. MBA 6.7% vs. PBA 13.6% vs. AA 10.2%; p=.29). Postoperative neuropathy occurred most after proximal brachial access (DBA 1.1% vs. MBA 1.3% vs. PBA 9.3 % vs. AA 5.1%; p=.003). There were no differences in cerebrovascular complications between access sides (right 5.9% vs. left 4.1% vs. bilateral 5%; p=.75). Significantly more overall access complications were seen after a percutaneous approach (29.2% vs. 6.8%; p=.002). In multivariate analysis the risk for access complications after open approach was decreased by male gender (OR 0.27; CI 95% 0.10 - 0.72; p= .009), while an increase in age per year (OR 1.08; CI 95% 1.004 - 1.179; p=.039) and diabetes mellitus type 2 (OR 3.70; CI 95% 1.20 - 11.41; p= .023) increased the risk.

CONCLUSION

Between the four access localizations, there were no differences in overall access complications. Female gender, diabetes mellitus type 2 and ageing increased the risk for access complications after surgical approach. Furthermore, a percutaneous upper extremity access resulted in higher complication rates than a surgical approach.

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.

The Supera Interwoven Nitinol Stent as a Flow Diverting Device in Popliteal Aneurysms

Purpose

The feasibility of using a compressed interwoven Supera stent as a flow diverting device for popliteal aneurysms was recently demonstrated in patients. It is unclear, however, what the optimal flow diverting strategy is, because of the fusiform shape of popliteal aneurysms and their exposure to triphasic flow. To assess this flow diverting strategy for popliteal aneurysms, flow profiles and thrombus formation likelihood were investigated in popliteal aneurysm models.

Materials and Methods

Six popliteal aneurysm models were created and integrated into a pulsatile flow set-up. These models covered a bent and a straight anatomy in three configurations: control, single-lined and dual-lined Supera stents. Two-dimensional flow velocities were visualized by laser particle image velocimetry. In addition, the efficacy of the stent configurations for promoting aneurysm thrombosis was assessed by simulations of residence time and platelet activation.

Results

On average for the two anatomies, the Supera stent led to a twofold reduction of velocities in the aneurysm for single-lined stents, and a fourfold reduction for dual-lined stents. Forward flow was optimally diverted, whereas backward flow was generally deflected into the aneurysm. The dual-lined configuration led to residence times of 15–20 s, compared to 5–15 s for the single stent configurations. Platelet activation potential was not increased by the flow diverting stents.

Conclusion

A compressed Supera stent was successfully able to divert flow in a popliteal aneurysm phantom. A dual-lined configuration demonstrated superior hemodynamic characteristics compared to its single-lined counterpart.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00270-022-03118-x.

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.

Individual patient data meta-analysis of patients treated with a heparin-bonded Viabahn in the femoropopliteal artery for chronic limb-threatening ischemia

Objectives

The aim of the study was to analyze available data on patients treated for chronic limb‐threatening ischemia (CLTI) with the heparin‐bonded Viabahn endoprosthesis.

Background

The patency of self‐expanding covered stents in patients with complex femoropopliteal lesions is encouraging. However, data were mostly derived in patients with intermittent claudication. Patients with CLTI often have more advanced disease and worse outcome.

Methods

After the abstract screening, full‐text papers were checked. Authors were approached to consider joining the consortium. Data were sent anonymously, databases were merged and an individual patient data meta‐analysis was performed. Kaplan–Meier curves were used to calculate the freedom from amputations, the amputation‐free survival, and patency rates.

Results

Seven studies were enrolled, representing 161 limbs that were treated for CLTI. Median lesion length was 28.0 cm (interquartile range 25.0–33.0 cm) and 82.7% were chronic total occlusions. The technical success rate was 98.1% and the 30‐day mortality 1.9%. Through 2‐year follow‐up, the freedom‐from‐major‐amputations was 99.3%, with an amputation‐free survival of 78.8%. The freedom‐from‐loss‐of primary, primary‐assisted, and secondary patency was 70.4%, 71.8%, and 88.2%, respectively, at 1‐year and 59.5%, 62.7%, and 86.1% at 2‐year follow‐up, respectively. The reintervention‐free survival was 62.2% at a 2‐year follow‐up.

Conclusions

Treatment of femoropopliteal disease in CLTI patients with the use of the heparin‐bonded Viabahn is safe and effective with favorable clinical outcomes and low amputation rates. Reinterventions are needed in a subset of the population to maintain endoprosthesis patency. Close follow‐up using duplex is recommended to detect potential edge stenosis, allowing treatment before device occlusion.

Predictors of Abdominal Aortic Aneurysm Shrinkage after Endovascular Repair

Recent studies demonstrate that patients with a shrinking abdominal aortic aneurysm (AAA), one-year after endovascular repair (EVAR), have better long-term outcomes than patients with a stable AAA. It is not known what factors determine whether an AAA will shrink or not. In this study, a range of parameters was investigated to identify their use in differentiating patients that will develop a shrinking AAA from those with a stable AAA one-year after EVAR. Hundred-seventy-four patients (67 shrinking AAA, 107 stable AAA) who underwent elective, infrarenal EVAR were enrolled between 2011-2018. Long-term survival was significantly better in patients with a shrinking AAA, compared to those with a stable AAA (p = 0.038). Larger preoperative maximum AAA diameter was associated with an increased likelihood of developing AAA shrinkage one-year after EVAR-whereas older age and larger preoperative infrarenal β angle were associated with a reduced likelihood of AAA shrinkage. However, this multivariate logistic regression model was only able to correctly identify 66.7% of patients with AAA shrinkage from the total cohort. This is not sufficient for implementation in clinical care, and therefore future research is recommended to dive deeper into AAA anatomy, and explore potential predictors using artificial intelligence and radiomics.

Cost-Effectiveness of Urea Excipient-Based Drug-Coated Balloons for Chronic Limb-Threatening Ischemia from Femoropopliteal Disease in the Netherlands and Germany

PURPOSE

Drug-coated balloons (DCBs) for femoropopliteal peripheral artery disease have been shown to be clinically superior and cost-effective compared to conventional percutaneous transluminal angioplasty (PTA). However, few studies enrolled patients with chronic limb-threatening ischemia (CLTI). Our objective was to study the cost-effectiveness of endovascular treatment with versus without DCB in CLTI patient populations in the Netherlands and Germany.

MATERIAL AND METHODS

Target lesion revascularization (TLR) and major amputation rates were obtained from the CLTI subgroup of the IN.PACT Global study. Rates for "status quo" treatment involving PTA with primary or bailout stenting were derived from systematic literature search. Costs and cost-effectiveness were calculated using a decision-analytic Markov model considering, in the base case, a 2-year horizon, and strategy-specific quality-adjusted life year (QALY) gains calculated from survival and health state-specific utilities. A willingness-to-pay threshold of €50,000/QALY was assumed, and extensive sensitivity analyses were performed.

RESULTS

Model-projected 24-month probabilities of TLR were 26.2% and 32.8% for treatment with and without DCB, and probabilities for amputation were 2.8% and 11.9%, respectively. DCB added 0.017 QALYs while saving €1,030 in the Dutch setting and €513 in the German setting, respectively. DCB was found dominant or cost-effective across a wide range of assumptions.

CONCLUSION

Urea excipient drug-coated balloon therapy for treating CLTI from femoropopliteal artery disease is associated with improved patient outcomes and expected overall cost savings to payers in the Dutch and German healthcare systems, rendering it a cost-effective and likely dominant treatment strategy.

A systematic review on anatomical predictors of abdominal aortic aneurysm remodeling after endovascular repair

OBJECTIVE

Long-term outcomes after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) are inferior to open surgical repair with regard to reinterventions and late mortality. AAA sac remodeling after EVAR has been associated with endoleaks, reinterventions, and mortality. Therefore, predictors of AAA sac remodeling could indirectly give insight into long-term EVAR outcomes. This review aims to provide an overview of the evidence on anatomical predictors of positive and negative AAA sac remodeling after EVAR.

METHODS

A systematic literature review and analysis were conducted according to the PRISMA and Cochrane guidelines. PubMed and Scopus databases were searched using terms of AAA sac growth, shrinkage, and remodeling. Eligible articles were identified and only papers that included currently used endografts were included.

RESULTS

Nineteen studies that reported on a total of 27 anatomical parameters of the aortoiliac anatomy were included. Only 4 parameters were investigated by >5 studies, 7 parameters were investigated by 3-5 studies, 6 parameters were investigated by 2 studies, and 10 parameters were investigated by 1 study. For the presence of neck thrombus, 3 out of 4 studies reported similar results indicating that it may predict less AAA sac shrinkage. AAA thrombus, total AAA volume, flow-lumen volume, and the number of hostile neck parameters were only investigated by 2-3 studies, but they seem promising in predicting 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

This review presents neck thrombus, AAA thrombus, number of hostile neck parameters, total AAA volume, and AAA flow-lumen volume as important anatomical features that are likely to play a role in AAA remodeling after endovascular repair that should be further explored using advanced imaging techniques. This review also showed that strong consistent evidence on anatomical predictors of AAA sac remodeling after EVAR is lacking. Therefore, further research with large patient groups on a broad range of predictors of AAA sac change after EVAR is needed to complement the current gap in the evidence.

Incidence and predictive factors for endograft limb patency of the Fenestrated Anaconda™ endograft used for complex endovascular aneurysm repair

OBJECTIVE

To describe the incidence, risk factors and outcomes of treatment for limb occlusion in patients treated for complex (thoraco-)abdominal aortic aneurysms (AAA) with the Fenestrated Anaconda™.

METHODS

Between June 2010 and May 2018, 335 patients underwent elective fenestrated aortic aneurysm repair in 11 participating centers using the Fenestrated Anaconda™ with a median follow-up of 14.3 months (IQR 27.4). The primary outcome measure was freedom-from-limb-occlusion. Secondary outcome measures were freedom-from-limb-related-reintervention, secondary patency, and risk factors associated with limb occlusion.

RESULTS

Thirty (9.0%) patients presented with limb occlusion during follow-up with freedom-from-limb-occlusion of 98.5%, 91.2%, and 81.7% at 30-days, 1 and 5 years, respectively. In 87% of cases, no obvious cause for limb occlusion was documented. Primary occlusion occurred within 30-days in 36.7% and within 1 year in 80.0%. Twenty-three (6.9%) patients underwent an occlusion-related reintervention; seven (23.3%) patients were treated conservatively. Freedom-from-limb-occlusion-related-reintervention at 30-days, one and five years was 97.8%, 93.2% and 88.6%, respectively. Secondary patency was 91.3% after 1-month and 86.2% after 1 and 5 years, respectively. Female sex (OR 3.27 - 95% CI 1.28 to 8.34, P = .01) was a statistically significant predictor for limb occlusion. A higher percentage of thrombus in the aneurysm sac appeared to be protective for limb occlusion (0% compared to <25%: OR 0.22 - 95% CI 0.07 to 0.63, P = .01; 0% compared to 25-50%: OR 0.20 - 95% CI 0.07 to 0.57, P = .00 and 0% compared to >50%: OR 0.08 - 95% CI 0.02 to 0.38, P = .00), as did iliac angulation (OR 0.99 - 95% CI 0.98 to 1.00, P = .04).

CONCLUSION

Limb occlusion remains a significant impediment of endograft durability in patients treated with the Fenestrated Anaconda™, especially in female patients. Controversially, a high aneurysmal thrombus load and a high degree of iliac angulation appeared to be protective for limb occlusion, for which no obvious cause could be identified.

Solitary Iliac Branch Endoprosthesis placement for iliac aneurysms

INTRODUCTION

Isolated iliac artery aneurysms (IAA), accounting for 2-7 percent of all abdominal aneurysms, are nowadays often treated with the use of iliac branched endografts. Although outside of the manufacturer's instructions for use, iliac branched devices can be used solely, without the adjunctive placement of an EVAR device, for the treatment of isolated IAA. In this study we aim to describe the outcomes of the use of the Gore IBE device, without support of an infrarenal EVAR device, for the exclusion of isolated IAA.

DESIGN

This study is an international multicenter retrospective cohort analysis.

METHOD

All patients that were treated with a solitary IBE for IAA exclusion from 11-01-2013 up to 31-12-2018 were retrospectively reviewed. The primary outcome was technical success. Secondary outcomes included mortality, intraoperative and postoperative complications, and re-interventions.

RESULTS

In total 18 European and American centers participated, including 51 patients in which 54 IAAs were excluded. The technical success rate was 94.1%, with an assisted technical success rate of 96.1%. There was no 30-day mortality and a 98.1% patency of both the internal and external iliac artery was found at 24-months follow-up. At 24-months follow-up, 81.5% of patients were free of complications and 90% were free of a secondary intervention.

CONCLUSION

Treatment with a solitary IBE is a safe and, at midterm, effective treatment strategy in selected patients with a solitary IAA.

Validation of Central Pressure Estimation in Patients with an Aortic Aneurysm Before and After Endovascular Repair

PURPOSE

The aim of this study was to investigate if non-invasive central pressure estimations are accurate in patients with an abdominal aortic aneurysm, before and after endovascular repair. Secondary evaluation was if measurement-accuracy was dependent on anatomical characteristics.

METHODS

Procedural invasive and non-invasive pressure-measurements were performed simultaneously both before and after endovascular repair in 20 patients with an infrarenal abdominal aortic aneurysm. Invasive catheter measurements were performed in the abdominal aorta. A tonometric device was used to perform non-invasive pressure-wave-analysis at the radial artery. A generalized transfer-function was used to generate an ascending aortic waveform for both measurements, allowing for direct comparison.

RESULTS

Pre-treatment the mean differences between methods were - 5.5 mmHg (p = .904), - 11.8 (p < .001), and - 7.2 mmHg (p = .124) for central systolic, diastolic, and mean pressure, respectively. The accuracy was dependent of aneurysm sac volume and intraluminal thrombus volume. Post-treatment limits of agreement were smaller for all pressure parameters compared to pre-treatment. The mean differences were 6.5 mmHg (p = .007), - 6.4 (p < .020), and 1.6 mmHg (p = .370) for central systolic, diastolic, and mean pressure, respectively.

CONCLUSION

In untreated AAA's the accuracy of non-invasive central pressure estimation was acceptable (mean difference between 5 and 10 mmHg) when compared to invasive pressures, but dependent of AAA characteristics. After EVAR the accuracy of central pressure estimation improved (reduction of 75% of the mean difference between pre and post measurements) TRIAL REGISTRATION NUMBER: NCT03469388; 3-5-2018.

ACTION-1: study protocol for a randomised controlled trial on ACT-guided heparinization during open abdominal aortic aneurysm repair

BACKGROUND

Heparin is used worldwide for 70 years during all non-cardiac arterial procedures (NCAP) to reduce thrombo-embolic complications (TEC). But heparin also increases blood loss causing possible harm for the patient. Heparin has an unpredictable effect in the individual patient. The activated clotting time (ACT) can measure the effect of heparin. Currently, this ACT is not measured during NCAP as the standard of care, contrary to during cardiac interventions, open and endovascular. A RCT will evaluate if ACT-guided heparinization results in less TEC than the current standard: a single bolus of 5000 IU of heparin and no measurements at all. A goal ACT of 200-220 s should be reached during ACT-guided heparinization and this should decrease (mortality caused by) TEC, while not increasing major bleeding complications. This RCT will be executed during open abdominal aortic aneurysm (AAA) surgery, as this is a standardized procedure throughout Europe.

METHODS

Seven hundred fifty patients, who will undergo open AAA repair of an aneurysm originating below the superior mesenteric artery, will be randomised in 2 treatment arms: 5000 IU of heparin and no ACT measurements and no additional doses of heparin, or a protocol of 100 IU/kg bolus of heparin and ACT measurements after 5 min, and then every 30 min. The goal ACT is 200-220 s. If the ACT after 5 min is < 180 s, 60 IU/kg will be administered; if the ACT is between 180 and 200 s, 30 IU/kg. If the ACT is > 220 s, no extra heparin is given, and the ACT is measured after 30 min and then the same protocol is applied. The expected incidence for the combined endpoint of TEC and mortality is 19% for the 5000 IU group and 11% for the ACT-guided group.

DISCUSSION

The ACTION-1 trial is an international RCT during open AAA surgery, designed to show superiority of ACT-guided heparinization compared to the current standard of a single bolus of 5000 IU of heparin. A significant reduction in TEC and mortality, without more major bleeding complications, must be proven with a relevant economic benefit. TRIAL REGISTRATION {2A}: NTR NL8421 ClinicalTrials.gov NCT04061798 . Registered on 20 August 2019 EudraCT 2018-003393-27 TRIAL REGISTRATION: DATA SET {2B}: Data category Information Primary registry and trial identifying number ClinicalTrials.gov : NCT04061798 Date of registration in primary registry 20-08-2019 Secondary identifying numbers NTR: NL8421 EudraCT: 2018-003393-27 Source(s) of monetary or material support ZonMw: The Netherlands Organisation for Health Research and Development Dijklander Ziekenhuis Amsterdam UMC Primary sponsor Dijklander Ziekenhuis Secondary sponsor(s) N/A Contact for public queries A.M. Wiersema, MD, PhD Arno@wiersema.nu 0031-229 208 206 Contact for scientific queries A.M. Wiersema, MD, PhD Arno@wiersema.nu 0031-229 208 206 Public title ACT Guided Heparinization During Open Abdominal Aortic Aneurysm Repair (ACTION-1) Scientific title ACTION-1: ACT Guided Heparinization During Open Abdominal Aortic Aneurysm Repair, a Randomised Trial Countries of recruitment The Netherlands. Soon the recruitment will start in Germany Health condition(s) or problem(s) studied Abdominal aortic aneurysm, arterial disease, surgery Intervention(s) ACT-guided heparinization 5000 IU of heparin Key inclusion and exclusion criteria Ages eligible for the study: ≥18 years Sexes eligible for the study: both Accepts healthy volunteers: no Inclusion criteria: Study type Interventional Allocation: randomized Intervention model: parallel assignment Masking: single blind (patient) Primary purpose: treatment Phase IV Date of first enrolment March 2020 Target sample size 750 Recruitment status Recruiting Primary outcome(s) The primary efficacy endpoint is 30-day mortality and in-hospital mortality during the same admission. The primary safety endpoint is the incidence of bleeding complications according to E-CABG classification, grade 1 and higher. Key secondary outcomes Serious complications as depicted in the Suggested Standards for Reports on Aneurysmal disease: all complications requiring re-operation, longer hospital stay, all complications.

US Velocimetry in Participants with Aortoiliac Occlusive Disease

Background The accurate quantification of blood flow in aortoiliac arteries is challenging but clinically relevant because local flow patterns can influence atherosclerotic disease. Purpose To investigate the feasibility and clinical application of two-dimensional blood flow quantification using high-frame-rate contrast-enhanced US (HFR-CEUS) and particle image velocimetry (PIV), or US velocimetry, in participants with aortoiliac stenosis. Materials and Methods In this prospective study, participants with a recently diagnosed aortoiliac stenosis underwent HFR-CEUS measurements of the pre- and poststenotic vessel segments (August 2018 to July 2019). Two-dimensional quantification of blood flow was achieved by performing PIV analysis, which was based on pairwise cross-correlation of the HFR-CEUS images. Visual inspection of the entire data set was performed by five observers to evaluate the ability of the technique to enable adequate visualization of blood flow. The contrast-to-background ratio and average vector correlation were calculated. In two participants who showed flow disturbances, the flow complexity and vorticity were calculated. Results Thirty-five participants (median age, 67 years; age range, 56-84 years; 22 men) were included. Visual scoring showed that flow quantification was achieved in 41 of 42 locations. In 25 locations, one or multiple issues occurred that limited optimal flow quantification, including loss of correlation during systole (n = 12), shadow regions (n = 8), a short vessel segment in the image plane (n = 7), and loss of contrast during diastole (n = 5). In the remaining 16 locations, optimal quantification was achieved. The contrast-to-background ratio was higher during systole than during diastole (11.0 ± 2.9 vs 6.9 ± 3.4, respectively; P < .001), whereas the vector correlation was lower (0.58 ± 0.21 vs 0.47 ± 0.13; P < .001). The flow complexity and vorticity were high in regions with disturbed flow. Conclusion Blood flow quantification with US velocimetry is feasible in patients with an aortoiliac stenosis, but several challenges must be overcome before implementation into clinical practice. Clinical trial registration no. NTR6980 © RSNA, 2021 Online supplemental material is available for this article.

An International, Multicenter Retrospective Observational Study to Assess Technical Success and Clinical Outcomes of Patients Treated with an Endovascular Aneurysm Sealing Device for Type III Endoleak

INTRODUCTION

Type III endoleaks post-endovascular aortic aneurysm repair (EVAR) warrant treatment because they increase pressure within the aneurysm sac leading to increased rupture risk. The treatment may be difficult with regular endovascular devices. Endovascular aneurysm sealing (EVAS) might provide a treatment option for type III endoleaks, especially if located near the flow divider. This study aims to analyze clinical outcomes of EVAS for type III endoleaks after EVAR.

METHODS

This is an international, retrospective, observational cohort study including data from 8 European institutions.

RESULTS

A total of 20 patients were identified of which 80% had a type IIIb endoleak and the remainder (20%) a type IIIa endoleak. The median time between EVAR and EVAS was 49.5 months (28.5-89). Mean AAA diameter prior to EVAS revision was 76.6±19.9 mm. Technical success was achieved in 95%, 1 patient had technical failure due to a postoperative myocardial infarction resulting in death. Mean follow-up was 22.8±15.2 months. During follow-up 1 patient had a type Ia endoleak, and 1 patient had a new type IIIa endoleak at an untreated location. There were 5 patients with aneurysm growth. Five patients underwent AAA-related reinterventions indications being: growth with type II endoleak (n=3), type Ia endoleak (n=1), and iliac aneurysm (n=1). At 1-year follow-up, the freedom from clinical failure was 77.5%, freedom from all-cause mortality 94.7%, freedom from aneurysm-related mortality 95%, and freedom from aneurysm-related reinterventions 93.8%.

CONCLUSION

The EVAS relining can be safely performed to treat type III endoleaks with an acceptable technical success rate, a low 30-day mortality rate and no secondary ruptures at short-term follow-up. The relatively low clinical success rates, related to reinterventions and AAA enlargement, highlight the need for prolonged follow-up.

Hemodynamic Comparison of Stent-Grafts for the Treatment of Aortoiliac Occlusive Disease

Purpose:

To compare the flow patterns and hemodynamics of the AFX stent-graft and the covered endovascular reconstruction of aortic bifurcation (CERAB) configuration using laser particle image velocimetry (PIV) experiments.

Materials and Methods:

Two anatomically realistic aortoiliac phantoms were constructed using polydimethylsiloxane polymer. An AFX stent-graft with a transparent cover made with a new method was inserted into one phantom. A CERAB configuration using Atrium’s Avanta V12 with transparent covers made with a previously established method was inserted into the other phantom, both modified stent-grafts were suitable for laser PIV, enabling visualization of the flow fields and quantification of time average wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT).

Results:

Disturbed flow was observed at the bifurcation region of the AFX, especially at the end systolic velocity (ESV) time-point where recirculation was noticeable due to vortical flow. In contrast, predominantly unidirectional flow was observed at the CERAB bifurcation. These observations were confirmed by the quantified hemodynamic results from PIV analysis where mean TAWSS of 0.078 Pa (range: 0.009–0.242 Pa) was significantly lower in AFX as compared with 0.229 Pa (range: 0.013–0.906 Pa) for CERAB (p<0.001). Mean OSI of 0.318 (range: 0.123–0.496) in AFX was significantly higher than 0.252 (range: 0.055–0.472) in CERAB (p<0.001). Likewise, mean RRT of 180 Pa−1 (range: 9–3603 Pa−1) in AFX was also significantly higher than 88 Pa−1 (range: 2–840 Pa−1) in CERAB (p=0.0086).

Conclusion:

In this in vitro study, the flow pattern of a modified AFX stent-graft was found to be more disturbed especially at the end systolic phase, its hemodynamic outcomes less desirable than CERAB configuration.

Clinical Relevance:

While the AFX stent-graft has an advantage over the CERAB configuration in eliminating radial mismatch, and maintaining the anatomical bifurcation for future endovascular intervention, this in vitro study revealed that the associated lower TAWSS, higher OSI and RRT may predispose to thrombosis and are, thus, less desirable as compared to a CERAB configuration. Further investigation is warranted to confirm whether these findings translate into the clinical setting.

Survival After Endovascular Aneurysm Sealing Compared With Endovascular Aneurysm Repair

INTRODUCTION

Endovascular aneurysm sealing (EVAS) is a sac-filling device with a blunted systemic inflammatory response compared to conventional endovascular aneurysm repair (EVAR), with a suggested impact on all-cause mortality. This study compares mortality after both EVAS and EVAR.

MATERIALS AND METHODS

This is a retrospective observational study including data from 2 centres, with ethical approval. Elective procedures on asymptomatic infrarenal aneurysms performed between January 2011 until April 2018 were enrolled. Laboratory values (serum creatinine, haemoglobin, white blood cell count, platelet count) were measured pre- and postoperatively and at 1 and 2 years, respectively. Mortality and cause of death were recorded during follow-up.

RESULTS

A total of 564 patients were included (225 EVAS, 369 EVAR), after propensity score matching there were 207 patients in both groups. Baseline characteristics were similar, except for larger neck angulation and more pulmonary disease in the EVAR group. The median follow-up time was 49 (EVAS) and 44 (EVAR) months. No significant differences regarding creatinine and haemoglobin were observed. Preoperative white blood cell count was higher in the EVAR group (p=0.011), without significant differences during follow-up. Median platelet count was lower in the EVAR group preoperatively (p=0.001), but was significantly higher at 1 year follow-up (p=0.003). There were 43 deaths within the EVAS group (20.8%) and 52 within the EVAR group (25.1%) (p=0.293). Of these, 4 were aneurysm related (EVAS n=3, EVAR n=1; p=0.222) and 14 cardiovascular (EVAS n=6, EVAR n=8, p=0.845). For the EVAS cohort, survival was 95.5% at 1 year and 74.9% at 5 years. For the EVAR cohort, this was 93.3% at 1 year and 75.5% at 5 years. No significant differences were observed in causes of death.

CONCLUSION

This study showed comparable survival rates through 5 years between EVAS and EVAR with a tendency toward higher inflammatory response in the EVAR patients through the first 2 years.

One Year Outcomes of an International Multicentre Prospective Cohort Study on the Gore Excluder Iliac Branch Endoprosthesis for Aorto-Iliac Aneurysms

OBJECTIVE

The Gore Excluder Iliac Branch Endoprosthesis (IBE) was developed to preserve perfusion in the hypogastric artery after endovascular repair of aorto-iliac aneurysms. This study reports the 12 month technical and clinical outcomes of treatment with this device.

METHODS

This study was a physician initiated international multicentre, prospective cohort study. The primary endpoint was primary patency of the hypogastric branch at 12 months. Secondary endpoints included technical and clinical outcomes. Patients with an indication for elective treatment with the Gore Excluder IBE were enrolled between March 2015 and August 2018. Baseline and procedural characteristics, imaging data, physical examinations and questionnaire data (Walking Impairment Questionnaire [WIQ], EuroQol-5-Dimensions [EQ5D], International Index of Erectile Function 5 [IIEF-5]) were collected through 12 month follow up.

RESULTS

One hundred patients were enrolled of which 97% were male, with a median age of 70.0 years (interquartile range [IQR] 64.5 - 75.5 years). An abdominal aortic aneurysm (AAA) above threshold for treatment was found in 42.7% and in the remaining patients the iliac artery diameter was the indication for treatment. The maximum common iliac artery (CIA) diameter on the Gore Excluder IBE treated side was 35.5 mm (IQR 30.8 - 42.0) mm. Twenty-two patients received a bilateral and seven patients had an isolated IBE. Median procedural time was 151 minutes (IQR 117 - 193 minutes) with a median hospital stay of four days (IQR 3 - 5 days). Primary patency of the IBE at 12 month follow up was 91.3%. Primary patency for patients treated inside and outside the instructions for use were 91.8% and 85.7%, respectively (p = .059). Freedom from secondary interventions was 98% and 97% at 30 days and 12 months, respectively. CIA and AAA diameters decreased significantly through 12 months. IIEF-5 and EQ5D scores remained stable through follow up. Patency of the contralateral internal iliac artery led to better IIEF-5 outcomes. WIQ scores decreased at 30 days and returned to baseline values through 12 months.

CONCLUSION

Use of the Gore Excluder IBE for the treatment of aorto-iliac aneurysms shows a satisfactory primary patency through 12 months, with significant decrease of diameters, a low re-intervention rate, and favourable clinical outcomes.

Efficacy of an autologous blood patch for prolonged air leak, a systematic review

BACKGROUND

Prolonged air leak (PAL) following pulmonary surgery remains a clinical challenge and sometimes needs surgical reintervention. An autologous blood patch (ABP) may provide a noninvasive method to cease air leak. Its value, however, is debatable. The aim of this systematic review is to synthesize evidence regarding the efficacy of ABP in patients with PAL.

METHODS

A comprehensive search for published studies was performed in the Medline database, Embase and the Cochrane library. Randomized controlled trials, case-control studies and case series in which a postoperative ABP was performed were included. Findings from these studies were tabulated and data was synthesized graphically. PROSPERO registration number CRD42020157591.

RESULTS

A total of 8 studies was included in the analysis, comprising 151 patients. Studies demonstrated heterogeneity in ABP timing and practice and an intermediate to high risk of bias was scored. The majority of studies demonstrated a beneficial effect of the ABP, with a high rate of success of over 89%. One randomized trial did not find a difference in time to cease of air leak following ABP compared with conservative tube thoracostomy. The overall complication rate was 10%.

CONCLUSIONS

Quality of included studies is limited due to lack of comparison groups. Synthesized data in this review demonstrates a high rate of successful procedures and acceptable complication rates, which seems to be encouraging to justify a large randomized clinical trial on the use of ABP for patients who suffer from PAL following thoracic surgery.

Hemodynamic Comparison of Stent-Grafts for the Treatment of Aortoiliac Occlusive Disease

PURPOSE

To compare the flow patterns and hemodynamics of the AFX stent-graft and the covered endovascular reconstruction of aortic bifurcation (CERAB) configuration using laser particle image velocimetry (PIV) experiments.

MATERIALS AND METHODS

Two anatomically realistic aortoiliac phantoms were constructed using polydimethylsiloxane polymer. An AFX stent-graft with a transparent cover made with a new method was inserted into one phantom. A CERAB configuration using Atrium's Avanta V12 with transparent covers made with a previously established method was inserted into the other phantom, both modified stent-grafts were suitable for laser PIV, enabling visualization of the flow fields and quantification of time average wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT).

RESULTS

Disturbed flow was observed at the bifurcation region of the AFX, especially at the end systolic velocity (ESV) time-point where recirculation was noticeable due to vortical flow. In contrast, predominantly unidirectional flow was observed at the CERAB bifurcation. These observations were confirmed by the quantified hemodynamic results from PIV analysis where mean TAWSS of 0.078 Pa (range: 0.009-0.242 Pa) was significantly lower in AFX as compared with 0.229 Pa (range: 0.013-0.906 Pa) for CERAB (p<0.001). Mean OSI of 0.318 (range: 0.123-0.496) in AFX was significantly higher than 0.252 (range: 0.055-0.472) in CERAB (p<0.001). Likewise, mean RRT of 180 Pa^-1 (range: 9-3603 Pa^-1) in AFX was also significantly higher than 88 Pa^-1 (range: 2-840 Pa^-1) in CERAB (p=0.0086).

CONCLUSION

In this in vitro study, the flow pattern of a modified AFX stent-graft was found to be more disturbed especially at the end systolic phase, its hemodynamic outcomes less desirable than CERAB configuration.

CLINICAL RELEVANCE

While the AFX stent-graft has an advantage over the CERAB configuration in eliminating radial mismatch, and maintaining the anatomical bifurcation for future endovascular intervention, this in vitro study revealed that the associated lower TAWSS, higher OSI and RRT may predispose to thrombosis and are, thus, less desirable as compared to a CERAB configuration. Further investigation is warranted to confirm whether these findings translate into the clinical setting.

Changes in Noninvasive Arterial Stiffness and Central Blood Pressure After Endovascular Abdominal Aneurysm Repair

Purpose:

To evaluate the impact of elective endovascular aneurysm repair (EVAR) on the carotid-femoral pulse wave velocity (cfPWV) and central pressure waveform, through 1-year follow-up.

Materials and Methods:

A tonometric device was used to measure cfPWV and estimate the central pressure waveform in 20 patients with an infrarenal abdominal aortic aneurysm scheduled for elective EVAR. The evaluated central hemodynamic parameters included the central pressures, the augmentation index (AIx), and the subendocardial viability ratio (SEVR). AIx quantifies the contribution of reflected wave to the central systolic pressure, whereas SEVR describes the myocardial perfusion relative to the cardiac workload. Measurements were performed before EVAR, at discharge, and 6 weeks and 1 year after EVAR.

Results:

CfPWV was increased at discharge (12.4±0.4 vs 11.3±0.5 m/s at baseline; p=0.005) and remained elevated over the course of 1-year follow-up (6 weeks: cfPWV = 12.2±0.5 m/s; 1 year: cfPWV = 12.2±0.7 m/s, p<0.05). After an initial drop in systolic central pressure at discharge, all the central pressures increased thereafter up to 1 year, without significant differences compared with baseline. The same was observed for the AIx and SEVR.

Conclusion:

Endovascular aortic aneurysm repair caused an increase in pulse wave velocity compared with baseline, which remained elevated through 1 year follow-up, which may be related to an increased cardiovascular risk. However, no differences in central pressure, augmentation index, and subendocardial viability ration were observed during follow-up.