Improving Bioactive Characteristics of Small Diameter Polytetrafluoroethylene Stent Grafts by Electrospinning: A Comparative Hemocompatibility Study.

Polytetrafluoroethylene (PTFE) is a commonly used biomaterial for the manufacturing of vascular grafts and several strategies, such as coatings, have been explored to improve the hemocompatibility of small-diameter prostheses. In this study, the hemocompatibility properties of novel stent grafts covered with electrospun PTFE (LimFlow Gen-1 and LimFlow Gen-2) were compared with uncoated and heparin-coated PTFE grafts (Gore Viabahn®) using fresh human blood in a Chandler closed-loop system. After 60 min of incubation, the blood samples were examined hematologically and activation of coagulation, platelets, and the complement system were analyzed. In addition, the adsorbed fibrinogen on the stent grafts was measured and the thrombogenicity was assessed by SEM. Significantly lower adsorption of fibrinogen was measured on the surface of heparin-coated Viabahn than on the surface of the uncoated Viabahn. Furthermore, LimFlow Gen-1 stent grafts showed lower fibrinogen adsorption than the uncoated Viabahn®, and the LimFlow Gen-2 stent grafts showed comparable fibrinogen adsorption as the heparin-coated Viabahn®. SEM analysis revealed no sign of thrombus formation on any of the stent surfaces. LimFlow Gen-2 stent grafts covered with electrospun PTFE exhibited bioactive characteristics and revealed improved hemocompatibility in terms of reduced adhesion of fibrinogen, activation of platelets, and coagulation (assessed by ß-TG and TAT levels) similar to heparin-coated ePTFE prostheses. Thus, this study demonstrated improved hemocompatibility of electrospun PTFE. The next step is to conduct in vivo studies to confirm whether electrospinning-induced changes to the PTFE surface can reduce the risk of thrombus formation and provide clinical benefits.

PROMISE international; a clinical post marketing trial investigating the percutaneous deep vein arterialization (LimFlow) in the treatment of no-option chronic limb ischemia patient.

BACKGROUND: Critical limb ischemia (CLI) is the clinical end stage of peripheral artery disease and is associated with high amputation, mortality rates and poor quality of life. For CLI patients with no revascularization options, venous arterialization could be an alternative technique for limb salvage. A systematic review and meta-analysis published in 2017 concluded that venous arterialization may be considered a viable alternative. A recent development, is the Percutaneous Deep Vein Arterialization (pDVA), that is CE-marked and currently under investigation of the FDA. This procedure, called LimFlow, is a novel, minimally invasive, endovascular approach to perform a venous arterialization procedure. The limited evidence for its use necessitates a scientific judgement of the pDVA. Therefore, we initiated a prospective clinical post market trial to investigate the outcome of the pDVA in no-option critical limb ischemia. METHODS/DESIGN: The objective of this prospective study is to collect "real-life" clinical data among a population of patients treated with the pDVA in order to evaluate the clinical effectiveness and safety of the LimFlow System in patients with no-option critical limb ischemia. This study is a single-arm, open-label, prospective, post-market follow-up study to be conducted on up to fifty (50) eligible patients with a twelve-month follow-up period. The Primary endpoint is measured by amputation free survival. Secondary endpoints are complete wound healing, primary and secondary patency, limb salvage, renal function and technical and procedural success. Patients will be assessed at regular intervals during one year after the initial percutaneous deep vein arterialization procedure through clinical evaluation and self-completed questionnaires. DISCUSSION: The last decade several studies have been published with promising results and the number of treated patients has considerably grown. Venous arterialization could be a valuable treatment option in patients with often no other options than amputation of the affected limb. The first results in men are promising although more research and long term follow up is needed to establish the efficacy of this new treatment modality. With this prospective study, we evaluate the clinical effectiveness and safety in patients with no-option CLI treated with the pDVA (LimFlow System). TRIAL REGISTRATION: NCT03321552 .

Surgical and endovascular venous arterialization for treatment of critical limb ischaemia.

Patients with critical limb ischaemia have a poor life expectancy. Aggressive revascularization is accepted in order to preserve their independence in the final phase of their lives. Bypass surgery and more recently endovascular interventions with angioplasty and stenting have become the treatment of choice to prevent amputation and to resolve pain. However, as many as 20 % of patients with critical limb ischaemia are unsuitable candidates for a vascular intervention because of extensive occlusions of outflow in the crural and pedal vessels. Such "no-option critical limb ischaemia" may be treated with venous arterialization. In the present review, we discuss the history of the venous arterialization procedure, the mechanisms, the different techniques, and complications of venous arterialization.

A Novel Implant for the Prophylactic Treatment of Impending Pathological Fractures of the Proximal Femur: Results from a Prospective, First-in-Man Study.

OBJECTIVES: To prospectively evaluate a novel implant, Y-STRUT® (Hyprevention, Pessac, France), designed to provide prophylactic reinforcement of the proximal femur in metastatic patients. METHODS: Ten patients presenting lytic lesions of the proximal femur were to be treated. The device consisted of two components implanted in the proximal femur, combined with bone cement. Patients were followed at 2, 6 and 12 months to record technical feasibility, safety and efficacy parameters of the procedure. RESULTS: All patients (62 years, 67% male) presented a pertrochanteric lesion shown on imaging with an average Mirels' score of 9.42 (range 8-11). Procedures were performed by interventional radiologists, under general anesthesia in 97 ± 28 min, with 9.2 ± 3.1 ml of cement injected. Hospitalization duration was 2.3 ± 1.4 days. A median follow-up of 237 days (range 24-411) was reported. Wound healing was achieved in all patients, with no case of wound infection, bleeding, leakage or inflammation. Among the patients evaluated, 86% could resume walking at hospital discharge. Visual Analogue Scale decreased from 3.6 ± 2.9 before treatment to 1.3 ± 0.8 at 1 year. OHS-12 score increased from 30 ± 10 at baseline to 37 ± 6 at 1 year. CONCLUSIONS: Results from this first-in-man study conducted in patients with metastatic bone disease show the feasibility and the safety of the intervention, with a short hospitalization, when performed following the operating instructions. Initial data showing pain-level diminution and increase in OHS-12 score indicate that both symptomatic and functional conditions of the patients were improved 1 year after the implantation of this novel implant. LEVEL OF EVIDENCE: Level 4, Case Series.

First experience with endovascular ultrasound renal denervation for the treatment of resistant hypertension.

AIMS: To evaluate a novel modality utilising ultrasound for renal denervation designed to reduce the duration of the intervention as well as to increase the consistency of the clinical outcome. METHODS AND RESULTS: Eleven consecutive patients suffering from resistant hypertension as defined by the ESH-ESC guidelines were treated by transcatheter renal denervation using the CE-marked PARADISE™ technology (ReCor Medical, Ronkonkoma, NY, USA). An average of 5.1 ultrasound emissions were delivered in each subject for a total denervation duration of less than four minutes and the treatment was well tolerated by all patients. Both office and home blood pressure measurements showed an immediate, significant and sustained decrease in blood pressure. Three-month results were comparable to published data on radiofrequency renal denervation with an average reduction in office and home blood pressure of -36/-17 mmHg and -22/-12 mmHg, respectively. CONCLUSIONS: Ultrasound renal denervation appears to be a safe and effective treatment for resistant hypertension and further studies will be performed to confirm these preliminary results.