Polymer-based drug-eluting stent treatment extends the time to reintervention for patients with symptomatic femoropopliteal artery disease: clinical evidence and potential economic value.

Aim: Use long-term follow-up data from the IMPERIAL study to determine whether drug-eluting polymer-based nitinol stent treatment can delay the time to repeat intervention for femoropopliteal artery disease and how such a delay may result in cost savings in a value-based episode of care. Patients & methods: The IMPERIAL randomized controlled trial was an international study of a paclitaxel-eluting polymer-coated stent (Eluvia, Boston Scientific, MA, USA) versus a polymer-free paclitaxel-coated stent (Zilver PTX, Cook Corporation, IN, USA) for treating lesions of the femoropopliteal arterial segment. Study patients (n = 465) had symptomatic lower limb ischemia. Safety and efficacy assessments were performed through 5 years. Mean time to first reintervention was calculated in post-hoc analysis for patients who underwent a clinically driven target lesion revascularization (CD-TLR) through 3 or 5 years following the index procedure. To simulate potential cost savings associated with differential CD-TLR burden over time, a cost-avoidance analysis using input parameters from IMPERIAL and US 100% Medicare standard analytical files was developed. Results: Among patients with a first CD-TLR through 3 years of follow-up, mean time to reintervention was 5.5 months longer (difference 166 days, 95% CI: 51, 282 days; p = 0.0058) for patients treated with Eluvia (n = 56) than for those treated with Zilver PTX (n = 30). Through the 5-year study follow-up period, CD-TLR rates were 29.3% (68/232) for Eluvia and 34.2% (39/114) for Zilver PTX (p = 0.3540) and mean time to first reintervention exceeded 2 years for patients treated with Eluvia at 737 days versus 645 days for the Zilver PTX group (difference 92 days, 95% CI: -85, 269 days; p = 0.3099). Simulated savings considering reinterventions occurring over 1 and 5 years following initial use of Eluvia over Zilver PTX were US $1,395,635 and US $1,531,795, respectively, when IMPERIAL CD-TLR rates were extrapolated to 1000 patients. Conclusion: IMPERIAL data suggest initial treatment with Eluvia extends the time patients spend without undergoing reintervention. This extension may be associated with cost savings in relevant time frames.

Low-Cost Biobased Coatings for AM60 Magnesium Alloys for Food Contact and Harsh Environment Applications.

Low-cost, environmentally friendly and easily applicable coating for Mg alloys, able to resist in real world conditions, are studied. Coatings already used for other metals (aluminum, steel) and never tested on Mg alloy for its different surface and reactivity were deposited on AM60 magnesium alloys to facilitate their technological applications, also in presence of chemically aggressive conditions. A biobased PA11 powder coating was compared to synthetic silicon-based and polyester coatings, producing lab scale samples, probed by drop deposition tests and dipping in increasingly aggressive, salty, basic and acid solutions, at RT and at higher temperatures. Coatings were analyzed by SEM/EDX to assess their morphology and compositions, by optical and IR-ATR microscopy analyses, before and after the drop tests. Migration analyses from the samples were performed by immersion tests using food simulants followed by ICP-OES analysis of the recovered simulant to explore applications also in the food contact field. A 30 µm thick white lacquer and a 120 µm PA11 coating resulted the best solutions. The thinner siliconic and lacquer coatings, appearing brittle and thin in the SEM analysis, failed some drop and/or dipping test, with damages especially at the edges. The larger thickness is thus the unique solution for edgy or pointy samples. Finally, coffee cups in AM60 alloy were produced, as real word prototypes, with the best performing coatings and tested for both migration by dipping, simulating also real world aging (2 h in acetic acid at 70° and 24 h in hot coffee at 60 °C): PA11 resulted stable in all the tests and no migration of toxic metals was observed, resulting a promising candidate for many real world application in chemically aggressive environments and also food and beverage related applications.

Biocompatibility of new low-cost (α + ß)-type Ti-Mo-Fe alloys for long-term implantation.

In this work, two new α +â€¯ß titanium alloys with low contents of ubiquitous and low-cost alloying elements (i.e., Mo and Fe) were designed on the basis of the electronic parameters and molybdenum equivalent approaches. The designed Ti - 2Mo - 0.5Fe at. % (TMF6) and Ti - 3Mo - 0.5Fe at. % (TMF8) alloys were produced using arc melting process for studying their mechanical, electrochemical and cytotoxicity compatibilities and comparing these compatibilities to those of Ti-6Al-4V ELI alloy. The cost of the used raw materials for producing the TMF6 and TMF8 alloys are almost 1/6 of those for producing the Ti-6Al-4V ELI alloy. The hardness of the two alloys are higher than that of the Ti-6Al-4V ELI alloy, while their Young's moduli (in the range of 85-82 GPa) are lower than that of the Ti-6Al-4V ELI alloy (110 GPa). Increasing the Mo equivalent from 6 (in TMF6 alloy) to 8 (in TMF8 alloy) led to an increase in the plastic strain percent from 4% to 17%, respectively, and a decrease in the ultimate tensile strength from 949 MPa to 800 MPa, respectively. The microstructure of TMF6 alloy consists of α'/α″ phases, while TMF8 alloy substantially consists of α″ phase. The corrosion current densities and the film resistances of the new alloys are in the range of 0.70-1.07 nA/cm2 and on the order of 105â€¯Ω·cm2, respectively. These values are more compatible with biomedical applications than those measured for the Ti-6Al-4V ELI alloy. Furthermore, the cell viabilities of the TMF6 and TMF8 alloys indicate their improved compatibility compared to that of the Ti-6Al-4V ELI alloy. The CCK-8 (Cell Counting Kit-8) assay was conducted to investigate the cytotoxicity, proliferation, and shape index of the cells of the candidate alloys. Overall, the measured compatibility of the new V-free low-cost alloys, particularly TMF8, makes them promising candidates for replacing the Ti-6Al-4V ELI alloy in biomedical applications.

Drug-coated balloons are replacing the need for nitinol stents in the superficial femoral artery.

Amassed evidence from several randomized controlled trials and high quality meta-analyses clearly support the primary use of paclitaxel-coated balloons (PCB) in the superficial femoral artery over traditional plain balloon angioplasty or primary bare nitinol stenting with significantly lower vascular restenosis, less need for repeat procedures, improved quality of life and potential cost savings for the healthcare system. Stents may be reserved for bail-out in case of a suboptimal dilatation result, and for selected more complex lesions, or in case of critical limb ischemia in order to eliminate vessel recoil and maximize immediate hemodynamic gain. Debulking atherectomy remains unproven, but holds a lot of promise in particular in combination with PCBs, in order to improve compliance of the vessel wall by plaque removal, allow for a better angioplasty result and optimize drug transfer and bioavailability. The present overview summarizes and discusses current evidence about femoropopliteal PCB angioplasty compared to the historical standard of plain old balloon angioplasty and bare nitinol stents. Available evidence is appraised in the context of clinically meaningful results, relevant unresolved issues are highlighted, and future trends are discussed.

Surgical bypass versus metallic stent for unresectable pancreatic cancer.

With the development of interventional radiology and endoscopy, the practice of inserting expandable metallic stents for malignant jaundice has become widespread. Many studies have compared surgical bypass with polyethylene stents, or metallic stents with polyethylene stents. However, few data are available on the comparison of surgical bypass and metallic stents. The aim of this study was to compare the patient's postprocedure course and the cost performance of surgical bypass and metallic stents in patients with unresectable pancreatic cancer. The parameters analyzed were the rates of procedural and therapeutic success, duration of hospital stay, prevalence of early and late complications, cost performance, and prognosis. The rates of procedural and therapeutic success were excellent with both palliative treatments. With surgical bypass, there was a low prevalence of late complications, but duodenal obstruction sometimes occurred in patients without gastric bypass. With metallic stents, there was shorter hospitalization and lower cost, but a higher prevalence of late complications. Stent occlusion tended to occur in patients with uncovered metallic stents. There was no difference in the prognosis between the two palliative treatments. Thus, in consideration of the poor prognosis of pancreatic cancer, in patients with unresectable pancreatic cancer, insertion of covered metallic stents would be preferable to surgical bypass, because of the subsequent short hospitalization and the low cost. On the other hand, in patients with a relatively long expected prognosis, or in those with existing duodenal obstruction, biliary bypass with gastrojejunostomy may provide an advantage.

An economic model to assess the cost and benefits of the routine use of silver alloy coated urinary catheters to reduce the risk of urinary tract infections in catheterized patients.

Prevalence studies generally find nosocomial urinary tract infections to be the most common type of nosocomial infection, accounting for between 21% and 45% of all HAIs. The main risk factor appears to be the presence of a urinary catheter, with an estimated 80% of these infections being associated with their use. This paper describes a model which quantifies the extent of the burden of these infections in terms of the number of patients affected and the costs incurred by the hospital sector; and identifies the potential benefits of the routine use of silver alloy coated catheters, as a means of reducing the incidence of this type of infection. An illustrative model of the annual costs and benefits associated with the routine use of this intervention in adult, non-day case patients admitted to the medical and surgical specialties of NHS hospitals throughout England is presented. The results suggest that a 14.6% reduction in the incidence of urinary tract infections in catheterized medical patients, and a 11.4% reduction in catheterized surgical patients, would cover the cost of the intervention. Any further reduction in incidence would result in net positive benefits.

Esophageal fistula sealing: choice of stent, practical management, and cost.

BACKGROUND: Three models of covered metal stents are available to seal esophageal fistulas. METHODS: Stainless steel covered stents were inserted in 5 patients (group I); nitinol covered stents were inserted in 12 patients (group II) with malignant (n = 14) or benign (n = 3) esophageal fistulas. RESULTS: Stent positioning was satisfactory in all cases. Fistula sealing was complete in 1 of 5 (20%) and 12 of 12 (100%) patients of groups I and II, respectively (p < 0.005). Continued esophageal leakage was initially related to the passage of fluids alongside the stent covering (n = 3) and to early stent migration (n = 1). Complications related to stent placement were observed in 2 of 17 (12%) patients and were fatal. During follow-up (mean 153 +/- 143 days), esophageal fistulas relapsed after initial sealing in 5 of 13 (38%) patients. Further treatment (glue or fibrin sealant injection, additional stent insertion) was attempted in 7 cases of persistent or relapsing esophageal fistula, with sealing obtained in 5 of them. The costs per patient and per day free from symptoms due to the esophageal fistula were $106 and $57 in groups I and II, respectively. CONCLUSION: Nitinol covered stents more frequently provided complete esophageal fistula sealing, as compared with stainless steel covered stents. Further treatments tailored to the mechanisms of fistula persistence or relapse often provided sealing.