Outcomes and Comparative Analysis of the Initial Results of Standard Balloon Angioplasty Versus Drug-Coated Balloons Alone Versus in Association With Laser-Excimer Atherectomy in the Treatment of Femoropopliteal Artery In-Stent Restenosis (INTACT).

BACKGROUND: Despite improved patency with newer-generation nitinol stents, one-half of patients will require secondary interventions for in-stent restenosis (ISR). The best treatment strategy remains unclear. This study aimed to compare drug-coated balloons (DCBs) used alone or in association with excimer laser atherectomy (ELA) to simple percutaneous transluminal angioplasty (PTA) in the treatment of femoropopliteal-ISR. METHODS: The INTACT trial is a multicenter, prospective, triple-arm randomized trial conducted across 14 centers from December 2015 to November 2019. Patients Rutherford Class 2-5 with ISR≥70% were followed-up for 18 months. The primary efficacy endpoint was recurrent ISR>70% by duplex ultrasound analysis. The primary safety endpoint was major adverse events (MAEs) defined as death, major amputation, or target lesion revascularization (TLR). RESULTS: Around 134 subjects were randomized to PTA alone (n=41), PTA+DCB (n=43) or PTA+ELA+DCB (n=50). Procedural success was similar (p=.74), as was clinical success (p=.17). The number of recurrent ISR>70% decreased after PTA+ELA+DCB (30.0%; p=.04) and PTA+DCB (30.2%; p=.05) compared to PTA alone (51.2%). Primary patency was higher after PTA+ELA+DCB (log-rank p=.04) and PTA+DCB (log-rank p=.02) compared to PTA alone at 12 months (78.7% and 70.4% vs 61.5%) and 18 months (61.6% and 67.7% vs 37.3%). Freedom from MAEs was lower after PTA+DCB (27.9%) compared to PTA alone (53.7%; p=.02) but did not differ with PTA+ELA+DCB (40.0%). It was primarily driven by TLR; 2 major amputations occurred after PTA+ELA+DCB (4.0%; p=.18). CONCLUSION: This independent study demonstrated a decrease in recurrent ISR>70% and increase in primary patency up to 18 months after PTA+ELA+DCB and PTA+DCB compared to PTA alone in the treatment of FP-ISR. It did not show an increase in MAEs but could have lacked power. CLINICAL IMPACT: This multicenter, prospective, triple-arm randomized, controlled trial focuses on the results of adjunctive therapies, such as excimer laser atherectomy (ELA) and/or drug-coated balloons (DCBs) in the treatment of in-stent restenosis (ISR) in femoropopliteal lesions in 134 patients. It has the originality of being an independent study funded by a grant from the French Ministry of Health. This study confirms a significant decrease in recurrent ISR >70% and increase in primary patency up to 18 months after the use of ELA+DCB and DCBs compared to simple percutaneous transluminal angioplasty in the treatment of femoropopliteal ISR without an increase in major adverse events.

An angiosome-centred approach for TcpO2 electrode positioning.

Background: The latest guidelines propose a TcpO2 value of 30 mmHg to help to confirm the diagnosis of chronic limb threatening ischemia. However, placement of electrodes is not standardised. The relevance of an "angiosome-centred" approach for TcpO2 electrode positioning has never been evaluated. We therefore retrospectively analysed our TcpO2 results to study the impact of electrode placement on the different angiosomes of the foot. Patients and methods: Patients consulting the vascular medicine department laboratory for suspicion of CLTI using TcpO2 electrodes placement on the different angiosome arteries of the foot (first inter metatarsal space, lateral edge of the foot and plantar side of the foot) were included. As the mean intra-individual variation is reported to be 8 mmHg, a variation of mean TcpO2 for the 3 locations ≤8 mmHg was considered to be not clinically significant. Results: Thirty-four patients (34 ischemic legs) were analysed. The mean TcpO2 was higher at the lateral edge of the foot (55 mmHg) and plantar side of the foot (65 mmHg) than at the first intermetatarsal space (48 mmHg). There was no clinically significant variation of mean TcpO2 according to anterior/posterior tibial artery patency and fibular artery patency. This was present when stratifying on the number of patent arteries. Conclusions: The present study suggests that multi-electrode TcpO2 is not useful to assess tissue oxygenation in the different angiosomes of the foot to guide surgical decision; first intermetatarsal electrode alone would be preferred. TcpO2 seems rather to evaluate overall tissue oxygenation of the foot. Electrode location on the plantar side of the foot may overestimate results and lead to misinterpretation.

EndoSuture aneurysm repair versus fenestrated aneurysm repair in patients with short neck abdominal aortic aneurysm.

OBJECTIVE: The aim of this study was to compare midterm results of EndoAnchors in EndoSuture aneurysm repair (ESAR) versus fenestrated endovascular aneurysm repair (FEVAR) in short neck abdominal aortic aneurysm (AAA). METHODS: All patients who underwent an ESAR procedure for a short neck AAA at our center between September 2017 and May 2020 were considered for analysis. To form the control group, preoperative computed tomography angiography of patients who underwent FEVAR for juxtarenal AAA between April 2012 and May 2020 were reviewed and patients who met short neck criteria selected. A propensity-matched score on neck length and neck diameter was calculated, resulting in 18 matched pairs. AAA shrinkage, type Ia endoleaks (EL), AAA-related reinterventions, and AAA-related deaths were compared. RESULTS: The median AAA diameter was 54 mm (interquartile range [IQR], 52-61 mm) versus 58 mm (IQR, 53-63 mm) with a median neck length of 8 mm (IQR, 6-12 mm) vs 10 mm (IQR, 6-13 mm) in ESAR and FEVAR patients, respectively. Technical success was 100% in both groups. Procedural success was 94% in the ESAR group versus 100% in the FEVAR group. The median procedure duration was 138 mm (IQR, 113-182 mm) vs 240 mm (IQR, 199-293 mm) ( P < .001) and the median length of stay was 2 days (IQR, 2-3 days) vs 7 days (IQR, 6-7 days) (P < .001) in ESAR and FEVAR patients, respectively. No major hospital complications were observed in ESAR patients compared with two in FEVAR patients (11%) with one transient acute kidney injury and one transient paraplegia. The median follow-up was 23 months (IQR, 19-33 months) vs 36 months (IQR, 22-57 months) with 67% versus 61% AAA shrinkage in the ESAR and FEVAR groups, respectively (P = .73). No type Ia EL, proximal neck-related reinterventions, or AAA-related deaths were observed in either group. No AAA-related reintervention was observed in the ESAR group versus three reinterventions in the FEVAR group (P = .23). CONCLUSIONS: ESAR seems to be a safe technique with no major postoperative complications or reinterventions observed during follow-up. It seems to offer similar midterm results as FEVAR in terms of type Ia EL, aneurysm shrinkage, and aneurysm-related mortality. ESAR seems to be a good off-the-shelf alternative to FEVAR in case of technical constraints.

Particle Image Velocimetry to Evaluate Pulse Wave Velocity in Aorta Phantom with the lnD-U Method.

PURPOSE: Pulse wave velocity (PWV) is an indicator of arterial stiffness used in the prediction of cardiovascular disease such as atherosclerosis. Non-invasive methods performed with ultrasound probes allow one to compute PWV and aortic stiffness through the measurement of the aortic diameter (D) and blood flow velocity (U) with the lnD-U method. This technique based on in vivo acquisitions lacks validation since the aortic elasticity modulus cannot be verified with mechanical strength tests. METHOD: In the present study, an alternative validation is carried out on an aorta phantom hosted in an aortic flow simulator which mimics pulsatile inflow conditions. This in vitro setup included a Particle Image Velocimetry device to visualize flow in a 2D longitudinal section of the phantom, compute velocity fields (U), and track wall displacements in the aorta phantom to measure the apparent diameter (AD) variations throughout cycles. RESULTS: The lnD-U method was then applied to evaluate PWV (5.79 ± 0.33 m/s) and calculate the Young's modulus of the aorta phantom (0.56 ± 0.12 MPa). This last value was compared to the elasticity modulus (0.53 ± 0.07 MPa) evaluated with tensile strength tests on samples cut from the silicone phantom. CONCLUSION: The PIV technique PWV measurement showed good agreement with the direct tensile test method with a 5.6% difference in Young's modulus. Considering the uncertainties from the two methods, the measured elasticities are consistent and close to a 50-60 years old male aortic behavior. The choice of silicone for the phantom material is a relevant and promising option to mimic the human aorta on in vitro systems.

Monocyte Phenotypes and Physical Activity in Patients with Carotid Atherosclerosis.

Atherosclerosis is associated with low-grade inflammation involving circulating monocytes. It has been shown that the levels of intermediate pro-inflammatory monocytes are associated with cardiovascular mortality and risk of ischemic stroke. It also has been shown that physical activity (PA) decreases inflammation markers, incidence of strokes, and mortality. In this cross-sectional study, we tested the effect of PA on circulating monocytes phenotype rate. A total of 29 patients with a carotid stenosis > 50% were recruited. Levels of physical activity (MET.min/week) were measured by the GPAQ questionnaire, arterial samples of blood were collected to analyze monocyte phenotype (classical, intermediate and non-classical) assessed by flow cytometry, and venous blood samples were used to dose antioxidant activity and oxidative damage. Antioxidant capacity was reduced and oxidative damage increased in patients. There was a significant decrease in the percentage of classical and intermediate monocytes in moderately active patients as compared with non-active and highly active patients. Inversely, the rate of non-classical monocytes increased in moderately active patients. Intense PA appears to blunt the beneficial effects of moderate PA. Our study also suggests that PA could be beneficial in such patients by reducing the rate of intermediate monocytes known to predict the risk of ischemic stroke and by increasing the non-classical monocytes involved in lesions' healing. Nevertheless, a longitudinal study would be necessary to confirm this hypothesis.

Investigation of Blood Coagulation Using Impedance Spectroscopy: Toward Innovative Biomarkers to Assess Fibrinogenesis and Clot Retraction.

This study focused on a coagulation assessment based on the novel technique of blood-impedance-magnitude measurement. With the impedance characterization of recalcified human blood, it was possible to identify two significative biomarkers (i.e., measurable indicators) related to fibrin formation (1st marker) and clot retraction (2nd marker). The confocal microscopy of clotting blood provided a complete visual analysis of all the events occurring during coagulation, validating the significance of the impedance biomarkers. By analyzing the impedance phase angle (Φ) of blood during coagulation, as well as those of the clot and serum expelled after retraction, it was possible to further clarify the origin of the 2nd marker. Finally, an impedance-magnitude analysis and a rotational thromboelastometry test (ROTEM®) were simultaneously performed on blood sampled from the same donor; the results pointed out that the 1st marker was related to clotting time. The developed technique gives rise to a comprehensive and evolutive insight into coagulation, making it possible to progressively follow the whole process in real time. Moreover, this approach allows coagulation to be tested on any materials' surface, laying the ground for new studies related to contact coagulation, meaning, thrombosis occurring on artificial implants. In a near future, impedance spectroscopy could be employed in the material characterization of cardiovascular prostheses whose properties could be monitored in situ and/or online using effective biomarkers.

Effectiveness of an individualized home-based physical activity program in surgery-free non-endarterectomized asymptomatic stroke patients: a study protocol for the PACAPh interventional randomized trial.

BACKGROUND: Carotid atherosclerotic plaques remain silent until their rupture, which may lead to detrimental ischemic events such as strokes. This is due, in part, to intraplaque hemorrhages (IPH) and the resulting inflammatory processes, which may promote carotid plaque vulnerability. Currently, the benefits of carotid endarterectomy remain unclear for asymptomatic patients. Interestingly, the completion of physical activity (PA) may have beneficial effects; however, the paucity of current data warrants robust longitudinal interventions. We therefore aim to study the effects of a 6-month longitudinal personalized home-based PA program on IPH, biological, and inflammatory markers in asymptomatic stroke patients. METHODS: Eighty patients (≥ 18 years old) will be recruited for the Physical Activity and Carotid Atherosclerotic Plaque Hemorrhage (PACAPh) clinical trial from the Hospices Civils de Lyon. Patients will be eligible if they present with carotid stenosis ≥ 50% and are asymptomatic from any ischemic events for at least 6 months. Recruited patients will be randomized into either a PA or a control group, and assessed at baseline and after 6 months. At both time points, all patients will be assessed using magnetic resonance imaging to assess IPH, blood sampling to measure inflammatory markers and monocytic phenotyping, PA and sedentary behavior questionnaires, 6-min walking test, and maximal isometric quadricep contraction test. The randomized PA intervention will consist of reaching a daily walking step goal individually tailored to each patient. Steps will be collected using a wirelessly connected wristband. The number of steps completed by individuals in the PA group will be re-evaluated bimonthly to encourage walking habits. DISCUSSION: The PACAPh study is the first of its kind representing a feasible, easily accessible therapeutic strategy for asymptomatic stroke patients. We hypothesize that the personalized home-based PA program will reduce IPH and modulate inflammatory and biological parameters in patients presenting with carotid plaques. If the results of the PACAPh study prove to be beneficial on such health parameters, the implementation of such kind of intervention in the daily treatment of these patients would be an advantageous and cost-effective practice to adopt globally. TRIAL REGISTRATION: This study has been approved by the National Ethics Committee (IDRCB:2019-A01543-54/SI:19.06.21.40640). ClinicalTrials.gov NCT04053166.

In vitro flow study in a compliant abdominal aorta phantom with a non-Newtonian blood-mimicking fluid.

In vitro aortic flow simulators allow studying hemodynamics with a wider range of flow visualization techniques compared to in vivo medical imaging and without the limitations of invasive examinations. This work aims to develop an experimental bench to emulate the pulsatile circulation in a realistic aortic phantom. To mimic the blood shear thinning behavior, a non-Newtonian aqueous solution is prepared with glycerin and xanthan gum polymer. The flow is compared to a reference flow of Newtonian fluid. Particle image velocimetry is carried out to visualize 2D velocity fields in a phantom section. The experimental loop accurately recreates flowrates and pressure conditions and preserves the shear-thinning properties of the non-Newtonian fluid. Velocity profiles, shear rate, and shear stress distribution maps show that the Newtonian fluid tends to dampen the observed velocities. Preferential asymmetrical flow paths are observed in a diameter narrowing region and amplified in the non-Newtonian case. Wall shear stresses are about twice higher in the non-Newtonian case. This study shows new insights on flow patterns, velocity and shear stress distributions compared to rigid and simplified geometry aorta phantom with Newtonian fluid flows studies. The use of a non-Newtonian blood analog shows clear differences in flows compared to the Newtonian one in this compliant patient-specific geometry. The development of this aortic simulator is a promising tool to better analyze and understand aortic hemodynamics and to aid in clinical decision-making.

Natural History of Asymptomatic Superior Mesenteric Arterial Stenosis Depends on Coeliac and Inferior Mesenteric Artery Status.

OBJECTIVE: The benefit of preventive treatment for superior mesenteric artery (SMA) stenosis remains uncertain. The latest European Society for Vascular Surgery (ESVS) guidelines remain unclear given the lack of data in the literature. The aim of this study was to evaluate asymptomatic SMA stenosis prognosis according to the presence of associated coeliac artery (CA) and/or inferior mesenteric artery (IMA) stenosis. METHODS: This was a single academic centre retrospective study. The entire computed tomography (CT) database of a single tertiary hospital was reviewed from 2009 to 2016. Two groups were defined: patients with isolated > 70% SMA stenosis (group A) and patients with both SMA and CA and/or IMA > 70% stenosis (group B). Patient medical histories were reviewed to determine the occurrence of mesenteric disease (MD) defined as development of acute mesenteric ischaemia (AMI) or chronic mesenteric ischaemia (CMI). RESULTS: Seventy-seven patients were included. Median follow up was 39 months. There were 24 patients in group A and 53 patients in group B. In group B, eight (10.4%) patients developed MD with a median onset of 50 months. AMI occurred in five patients with a median of 33 months and CMI in three patients with a median of 88 months. Patients of group B developed more MD (0% vs. 15.1%; p = .052). The five year survival rate was 45% without significant difference between groups. CONCLUSION: Patients with SMA stenosis associated with CA and/or IMA seem to have a higher risk of developing mesenteric ischaemia than patients with isolated SMA stenosis. Considering the low life expectancy of these patients, cardiovascular risk factor assessment and optimisation of medical treatment is essential. Preventive endovascular revascularisation could be discussed for patients with non-isolated > 70% SMA stenosis, taking into account life expectancy.

Analysis of Preoperative CT Scan Can Help Predict Technical Failure of Endovascular Treatment of TASC C-D Aortoiliac Chronic Total Occlusions.

BACKGROUND AND AIMS: To evaluate if features of occlusion analyzable on preoperative computed tomography scan could predict risks of technical failure or iliac rupture of endovascular treatment of TransAtlantic InterSociety Consensus C-D aortoiliac chronic total occlusion. METHODS AND RESULTS: All patients treated by endovascular techniques for a TransAtlantic InterSociety Consensus C-D aortoiliac chronic total occlusion between 2009 and 2016 were included (107 patients, 148 iliac arteries). We evaluated the location of the occlusion and the importance of the arterial calcifications. For this factor, patients were divided into 3 groups: the Black occlusion group with mild or no calcifications, the white occlusion group with moderate no protrusive calcifications, and the white protrusive occlusion group with heavy endoluminal calcifications. Technical failure occurred in 11 iliac arteries and peroperative iliac rupture in 6. The location in the external iliac artery is the most significate risk factor of technical failure in univariate (OR = 9.93; P = 0.0012) and multivariate analysis (OR = 15.26; P = 0.0006). The presence of heavy endoluminal calcifications is a further significate risk factor (OR = 13.88; P = 0.0365). Rupture rate was comparable between the 3 groups. CONCLUSIONS: Preoperative computed tomography scan can predict risk of technical failure but not of iliac rupture.

Disruption of a Covered Nitinol Self Expanding Stent Graft Implanted in the Common Femoral Artery.

INTRODUCTION: Common femoral artery aneurysm is a rare condition and can be treated by open or endovascular surgery. There is a general understanding that open surgery is the recommended option because of the anatomical location and the biomechanical constraints posed by hip flexion. REPORT: The case of a 66 year old man treated with an endograft for an asymptomatic abdominal aortic aneurysm followed by the implantation of a nitinol covered stent graft (Fluency™, Bard Peripheral Vascular, Temple, AZ) for a 25 mm diameter left common femoral artery aneurysm is reported. Two years later, follow up revealed a rupture of the nitinol covered stent graft, requiring an open iliofemoral reconstruction. DISCUSSION: Systematic analysis with protocolised cleaning, and macroscopic and microscopic evaluation (Keyence VHX-600 digital microscope) of the explanted nitinol covered stent graft showed membrane perforation at the level of an acute angle formed by the struts.

Effect of beta-based sterilization on P(VDF-TrFE-CFE) terpolymer for medical applications.

Electroactive polymers (EAP) are one of the latest generations of flexible actuators, enabling new approaches to propulsion and maneuverability. Among them, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene/chlorotrifluoroethylene), abbreviated terpolymer, with its multifunctional sensing and actuating abilities as well as its impressive electrostrictive behavior, especially when being doped with an plasticizer, has been demonstrated to be a good candidate for the development of low-cost flexible guidewire tip for endovascular surgery. To minimize the possibility of bacterial, fungal, or viral disease transmission, all medical instruments (especially components made from polymers) must be sterilized before introduction into the patient. Gamma/beta (γ/ß) irradiation is considered to be one of the most efficient techniques for targeted reduction of microbials and viruses under low temperature, often without drastic alterations in device properties. However, radiation may cause some physical and chemical changes in polymers. A compromise is required to ensure sufficient radiation for microbial deactivation but minimal radiation to retain the material's properties. The main idea of this study aims at assessing the electromechanical performances and thermal/dielectric properties of ß-irradiated terpolymer-based sterilization treatment. Ionizing ß-rays did not cause any significant risk to the neat/plasticized terpolymers, confirming the reliability of such electrostrictive materials for medical device development.