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 &gt;4 mm, and a target lumen volume of &lt;20 mL or &gt;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 &lt; .001). The adjusted mean change in sac diameter at 1 year was −5.9 mm (95% CI, −7.5 to −4.4 mm; P &lt; .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.</p

Long-term prognostic risk in lower extremity peripheral arterial disease as a function of the number of peripheral arterial lesions

Background:  Although patients with peripheral artery disease (PAD) are known to have an increased risk of adverse prognosis, simple techniques to further risk-stratify PAD patients would be clinically useful. A plausible but unexplored factor to predict such risk would be greater disease burden, manifested as multiple lower extremity lesions. The aim of this study was to examine the association between having multiple versus isolated lower extremity PAD lesions and long-term prognosis. Methods and results:  A prospective cohort of 756 newly diagnosed PAD patients underwent duplex ultrasound testing to determine the number of lower extremity lesions. Cox regression models examined the independent association of lesion number (≥3 and 2 versus 1) and adverse prognosis (defined as a composite end point comprising first occurrence of either lower extremity amputation, admission for heart failure, nonfatal stroke, myocardial infarction, or unstable angina or mortality), adjusting for demographic and clinical risk factors. Analyses were replicated using an advanced Cox-based model for multiple events. A total of 173 patients (23%) had ≥3 lesions, 197 (26%) had 2 lesions, and 386 (51%) had 1 lesion. After a median follow-up of 3.2 years, patients with ≥3 lesions had an increased risk of experiencing a first adverse event (adjusted hazard ratio 1.60, 95% CI 1.08-2.38, P=0.020) and an increased risk of having multiple events (adjusted hazard ratio 1.53, 95% CI 1.08-2.18, P=0.018). Patients with 2 lesions had a prognosis similar to those with 1 lesion. Conclusions:  Among PAD patients, a greater number of lesions is associated with an increased risk of an adverse prognosis over 3 years of follow-up. Assessing the number of lower extremity lesions might serve as a simple risk-stratification tool at initial PAD diagnosis

The Dutch chronic lower limb-threatening ischemia registry (THRILLER): A study protocol for popliteal and infrapopliteal endovascular interventions

INTRODUCTION: Chronic limb-threatening ischemia (CLTI) is the end stage of peripheral arterial disease (PAD) and is associated with high amputation rates, mortality and disease-related health care costs. In infrapopliteal arterial disease (IPAD), endovascular revascularization should be considered for the majority of anatomical and clinical subgroups of CLTI. However, a gap of high-quality evidence exists in this field. The aim of the Dutch Chronic Lower Limb-Threatening Ischemia Registry (THRILLER) is to collect real world data on popliteal and infrapopliteal endovascular interventions. METHODS: THRILLER is a clinician-driven, prospective, multicenter, observational registry including all consecutive patients that undergo a popliteal or infrapopliteal endovascular intervention in seven Dutch hospitals. We estimate that THRILLER will include 400-500 interventions annually. Standardized follow-up visits with wound monitoring, toe pressure measurement and duplex ultrasonography will be scheduled at 6-8 weeks and 12 months after the intervention. The independent primary endpoints are primary patency, limb salvage and amputation free survival. Patients must give informed consent before participation and will be included according to predefined reporting standards. A data log of patients who meet the inclusion criteria but are not included in the registry will be maintained. We intend to conduct the first interim analysis two years after the start of inclusion. The results will be published in a scientific journal. DISCUSSION: Despite innovations in medical therapy and revascularization techniques, patients with CLTI undergoing endovascular revascularization still have a moderate prognosis. Previous prospective cohort studies were hampered by small sample sizes or heterogeneous reporting. Randomized controlled trials (RCTs) have high costs, potential conflicts of interest and give a limited reflection of daily practice. THRILLER aims to provide the largest prospective well phenotyped up-to-date dataset on treatment outcomes in CLTI patients to answer multiple underexplored research questions regarding diagnostics, medication, patient selection, treatment strategies and post intervention follow-up

The upside down Gore Excluder contralateral leg without extracorporeal predeployment for aortic or iliac aneurysm exclusion

Endovascular techniques, including branched devices to preserve the internal iliac artery are evolving rapidly, but in cases in which the diameter of the proximal sealing zone is larger than that of the distal sealing zone, a reversed tapered device is needed. We describe the off label use of the Gore Excluder contralateral leg endoprosthesis in an upside down configuration to accommodate this diameter mismatch. The preinsertion technical steps of stent graft preparation, which do not require extracorporeal predeployment, are described in detail. As such, an aneurysm of the internal iliac artery and a saccular abdominal aortic aneurysm were successfully excluded

A heparin-bonded vascular graft generates no systemic effect on markers of hemostasis activation or detectable heparin-induced thrombocytopeniaassociated antibodies in humans

ObjectivesAlmost a third of patients who undergo peripheral bypass procedures do not have suitable veins, making the use of prosthetic materials necessary. Prosthetic materials can cause platelet adhesion and activation of the coagulation cascade on the graft. One potential strategy to reduce this thrombogenicity is to covalently bind heparin to the endoluminal surface of grafts. This human in vivo study examined systemic effects of the endoluminal heparin and addressed whether graft implantation results in (1) a measurable reduction of systemic markers of hemostasis activation compared with control grafts and (2) antibody formation against heparin, potentially responsible for heparin-induced thrombocytopenia (HIT).MethodsThe study included 20 patients undergoing femoropopliteal bypass grafting, of whom 10 received a standard Gore-Tex Thin Walled Stretch Vascular Graft (W. L. Gore & Associates, Flagstaff, Ariz) and 10 received a heparin-bonded expanded polytetrafluoroethylene (ePTFE) graft (Gore-Tex Propaten Vascular Graft). Blood samples were drawn before and directly after the operation and at days 1, 3, 5, and week 6 after surgery. Established markers of in vivo activation of platelets and blood coagulation (prothrombin fragment 1+2, fibrinopeptide A, soluble glycoprotein V, thrombin-antithrombin complexes, and D-dimers) were measured using standard commercially available techniques. Antiplatelet factor 4/heparin antibody titers were measured using a commercially available enzyme-linked immunosorbent assay, and platelet counts were determined.ResultsNo statistical differences were observed in any of the markers of in vivo activation of platelets and blood coagulation between patients receiving Propaten or control ePTFE. Moreover, no antibodies against heparin could be demonstrated up to 6 weeks after implantation.ConclusionsNo measurable effect of heparin immobilization on systemic markers of hemostasis was found using a heparin-bonded ePTFE graft in vivo. Also, no antibodies against heparin could be detected up to 6 weeks after implantation

Evaluation of electrocardiogram-gated computed tomography angiography to quantify changes in geometry and dynamic behavior of the iliac artery after placement of the Gore Excluder Iliac Branch Endoprosthesis

BACKGROUND: The GORE® EXCLUDER® Iliac Branch Endoprosthesis (IBE) is designed to treat iliac aneurysms with preservation of blood flow through the internal iliac artery (IIA). Little is known about the influence of IBE placement on the IIA geometry. This study aimed to provide detailed insights in the dynamic behavior and geometry of the common iliac artery (CIA) and IIA trajectory and how these are influenced after treatment with an IBE. METHODS: Pre- and postoperative electrocardiogram-gated computed tomography angiography (ECG-gated CTA) scans were acquired in a prospective study design and analyzed with in-house written algorithms designed for aorto-iliac and endoprosthesis deformation evaluation. Cardiac pulsatility-induced motion patterns and pathlengths were computed by tracking predefined locations on the aorto-iliac tract. Centerlines through the CIA-IIA trajectory were used to investigate the static and dynamic geometry, including curvature, torsion, length and Tortuosity Index (TI). RESULTS: Fourteen CIA-IIA trajectories were analyzed before and after IBE placement. Cardiac pulsatility-induced motion and pathlengths increased after IBE placement, especially at mid IIA and the first IIA bifurcation (P≤0.04). After IBE placement, static and dynamic curvature, length and TI decreased significantly (P<0.05). Furthermore, the average dynamic torsion increased significantly (P=0.030). The remaining geometrical outcomes were not statistically significant. CONCLUSIONS: The placement of an IBE device stiffens and straightens the CIA-IIA trajectory. Its relation with clinical outcome is yet to be investigated, which can be done thoroughly with the ECG-gated CTA algorithms used in this study

Long-term prognostic risk in lower extremity peripheral arterial disease as a function of the number of peripheral arterial lesions

Background: Although patients with peripheral artery disease (PAD) are known to have an increased risk of adverse prognosis, simple techniques to further risk-stratify PAD patients would be clinically useful. A plausible but unexplored factor to predict such risk would be greater disease burden, manifested as multiple lower extremity lesions. The aim of this study was to examine the association between having multiple versus isolated lower extremity PAD lesions and long-term prognosis. Methods and Results: A prospective cohort of 756 newly diagnosed PAD patients underwent duplex ultrasound testing to determine the number of lower extremity lesions. Cox regression models examined the independent association of lesion number (>= 3 and 2 versus 1) and adverse prognosis (defined as a composite end point comprising first occurrence of either lower extremity amputation, admission for heart failure, nonfatal stroke, myocardial infarction, or unstable angina or mortality), adjusting for demographic and clinical risk factors. Analyses were replicated using an advanced Cox-based model for multiple events. A total of 173 patients (23%) had >= 3 lesions, 197 (26%) had 2 lesions, and 386 (51%) had 1 lesion. After a median follow-up of 3.2 years, patients with >= 3 lesions had an increased risk of experiencing a first adverse event (adjusted hazard ratio 1.60, 95% CI 1.08-2.38, P=0.020) and an increased risk of having multiple events (adjusted hazard ratio 1.53, 95% CI 1.08-2.18, P=0.018). Patients with 2 lesions had a prognosis similar to those with 1 lesion. Conclusions: Among PAD patients, a greater number of lesions is associated with an increased risk of an adverse prognosis over 3 years of follow-up. Assessing the number of lower extremity lesions might serve as a simple risk-stratification tool at initial PAD diagnosis

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 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}: ClinicalTrials.gov: NCT04061798NTR: [email protected]@wiersema.n