Standard Polytetrafluoroethylene Research Articles

Thermally rearranged nanofibrous composite membranes for carbon dioxide absorption and stripping

We develop thermally rearranged (TR) nanofibre membranes for the capture of CO2 using membrane gas absorption. The porous nature of the electrospun nanofibre membranes and the hydrophobicity of the TR polymers provide ideal properties for both CO2 absorption and stripping. The use of thermal rearrangement after fabricating the nanofibre composite structures (TR-NFM) also interconnects the nanofibres and greatly improves mechanical strength. Surface hydrophobicity is further increased by electrospraying of nanoparticles onto the nanofibre membrane surface to increase roughness (TR-NCM), leading to higher breakthrough pressures and stable CO2 stripping performance for up to 270 h at 100 °C without membrane wetting. The TR-NFM and TR-NCM membranes both show an order of magnitude increase in CO2 absorption flux compared to a standard polytetrafluoroethylene (PTFE) membrane, offering strong potential for commercial application.

Abstract 13904: Ex vivo Biomechanical Analysis of Elastic Artificial Chordae Implantation for Beating-heart Transapical Mitral Valve Repair

Introduction: Beating-heart transapical mitral valve repair represents a significant advancement in the minimally invasive treatment of mitral regurgitation. However, current techniques require increased artificial chordae length and altered anchoring position, which may increase the stresses on the suture. We hypothesized that artificial chordae manufactured with increased elasticity will dampen sharp increases in force, thus theoretically increasing durability. Methods: Porcine mitral valves (n=3) were mounted in a heart simulator and isolated mitral regurgitation was induced by cutting posterior primary chordae. Each valve was first repaired with standard CV-5 polytetrafluoroethylene (PTFE) suture affixed to a 3D-printed anchor with an embedded high-resolution Fiber Bragg Grating sensor to measure forces (Fig A). The repair was then repeated with an elastic suture manufactured using a biocompatible silicone and designed with a cross-sectional area of 0.56mm 2 , a geometry calculated to result in a desired 10-15% strain at relevant forces (Fig B). Results: Both materials allowed for successful repairs: mitral leakage volume was reduced from 28.29±4.83ml to 1.26±0.99ml ( p =0.009) with PTFE suture, and to 1.78±0.88ml ( p =0.008) with the elastic suture, with no significant difference between the repairs. Normalized force tracings (Fig C, standard deviation is shaded) revealed that the elastic suture resulted in a significantly lower peak systolic force when compared to PTFE suture (0.23±0.04N vs 0.32±0.03N, p =0.007). Conclusions: Artificial chordae with increased elasticity compared to traditional PTFE suture can dampen sharp peaks in force, thus offering a promising advancement in improving transapical repair durability. This proposal has the potential to apply to open-heart artificial chordae implantation as well. Future work to optimize suture material and manufacturability will help translate this development into clinical use.

Heparin-bonded versus standard polytetrafluoroethylene arteriovenous grafts: A Bayesian perspective on a randomized controlled trial for comparative effectiveness

BackgroundHeparin-bonded polytetrafluoroethylene grafts were marketed to improve hemodialysis access outcomes but are twice the cost of standard polytetrafluoroethylene. We launched a randomized trial of heparin-bonded polytetrafluoroethylene versus standard polytetrafluoroethylene for hemodialysis access to compare patency. Since the trial began, additional studies were published with heterogeneous findings. We performed an interim analysis by Bayesian methods using prior probability from meta-analysis of existing literature. MethodsNCT01601873 is a randomized, blinded trial of heparin-bonded polytetrafluoroethylene versus standard polytetrafluoroethylene for dialysis access at 5 sites. Planned sample size was 200 with 1-year primary patency as the primary endpoint. At interim analysis (50% of sample size at 1 year), we also performed a meta-analysis for 1-year primary patency with a random effects model to compute summary rate ratio and standard-error estimates. Meta-analysis estimates formed a prior probability for a Bayesian Cox regression model, and trial data were reanalyzed to develop posterior probability of heparin-bonded polytetrafluoroethylene effectiveness at our hypothesized effect size. Futility analysis was conducted using posterior probability estimates. ResultsOne hundred and five patients were enrolled at the time of interim analysis. One-year primary patency was 34.9% in the heparin-bonded-polytetrafluoroethylene group vs 32.7% in the standard-polytetrafluoroethylene group (P = .884). Summary rate ratio from the meta-analysis (1,209 patients) was 0.87 favoring heparin-bonded polytetrafluoroethylene (P = .33). Posterior hazard ratio from Cox regression was 0.90 (credible interval 0.70–1.13) favoring heparin-bonded polytetrafluoroethylene, which was not significant. Bayesian posterior probability of the a priori hypothesized 20% better patency with heparin-bonded polytetrafluoroethylene was 24%. Sample size to detect superiority with the small observed effect size would require about 3,800 subjects. ConclusionCurrent evidence does not demonstrate sufficiently large benefit of heparin-bonded polytetrafluoroethylene over standard polytetrafluoroethylene for dialysis access to justify higher cost. Given similar 1-year patency rates, a conclusive finding of superiority was judged to be infeasible, and the trial was stopped for futility.

Experimental investigation on characteristics of pulsed plasma thrusters with the propellant samples of modified PTFE filled Si, Al and Al2O3

As the inherent simplicity, pulsed plasma thrusters (PPTs) have a broad prospect on small satellites. However, these disadvantages including the late-time ablation and carbon deposition caused by the conventional use of the propellant of polytetrafluoroethylene (PTFE) limit the performance of PPTs. The promising alternative is to modify PTFE with inclusions, aiming at improving some characteristics while maintaining its most superiorities. Therefore, this paper presents an experimental investigation of characteristics of PPTs fed by propellant samples of modified PTFE filled Si, Al and Al2O3. The surface topography, energy-dispersive X-ray spectroscopy, emission spectra, plasma plume and performance parameters of the modified propellant samples were tested and compared with those of the standard pure PTFE in the operation context of PPTs. According to the experimental results, although the fillings could result in reverse plasma particles and lead the side surfaces to be ablated, they would effectively improve the specific impulse and the efficiency at the low discharge voltage.

Cost-Effectiveness Evaluation of Heparin Coated Versus Standard Graft for Bypass Surgery in Peripheral Artery Disease Alongside a Randomised Controlled Trial

Heparin coating has recently been shown to reduce the risk of graft failure in arterial revascularisation, at least transiently. The aim of this study was to assess the cost-effectiveness of heparin coated versus standard polytetrafluoroethylene grafts for bypass surgery in peripheral artery disease from a long-term healthcare system perspective. Cost-effectiveness evaluation was conducted alongside the Danish part of the Scandinavian Propaten trial in which 431 patients planned for femoro-femoral or femoro-popliteal bypass surgery were randomised to either type of graft and followed for 5 years. Based on the intention to treat principle, the differences in healthcare costs (general practice, prescription medication, hospital admission, rehabilitation, and long-term care in 2015 Euros), life years (LYs), and quality adjusted life years (QALYs) were analysed as arithmetic means with bootstrapped 95% confidence intervals. Cost-effectiveness acceptability curves were used to illustrate the probability of cost-effectiveness for a range of threshold values of willingness to pay (WTP). No statistically significant differences between the randomisation groups were observed for costs or gains of LYs or QALYs. The average cost per QALY was estimated at €10,792. For a WTP threshold of €40,000 per QALY, the overall probability of cost-effectiveness was estimated at 62%, but owing to cost savings in patients with critical ischaemia (cost per QALY <€0), it increased to 89% for this subgroup. Until further evidence, heparin coated grafts appear overall, to be cost-effective over standard grafts, but important heterogeneity between claudication and critical ischaemia should be noted. While the optimal choice for claudication remains uncertain, heparin coated grafts should be used for critical ischaemia.

Budget impact analysis of heparin-bonded polytetrafluoroethylene grafts (Propaten) against standard polytetrafluoroethylene grafts for below-the-knee bypass in patients with critical limb ischaemia in France

ObjectivesTo evaluate the budget impact of progressive replacement of standard polytetrafluoroethylene (PTFE) grafts by heparin-bound PTFE (Propaten) for below-the-knee (BTK) bypass in patients with critical limb ischaemia (CLI).DesignFrom a review...

Chipless Liquid Sensing Using a Slotted Cylindrical Resonator

A method for the wireless sensing of the permittivity and level of liquids is presented. The use of a simple, thin-film slotted cylindrical cavity wrapped around a standard polytetrafluoroethylene pipe is proposed. Wireless interrogation of the slot excites a resonant mode whose frequency is dependent on the liquid currently present within the pipe. The proposed method allows for measurements to be taken in situ with no requirement for taking samples of potentially hazardous liquids. The device is capable of sensing materials of high relative permittivity, including water, as well as very lossy liquids. A comprehensive set of results is presented, including measurements of butanol, ethanol, methanol, and water, for several device configurations. The proposed sensor is also shown to be sensitive to small changes in liquid level, allowing for accurate water-level measurements down to 0.1 ml. This sensor is a good candidate for very low-cost, low-complexity real-time monitoring of liquids.

External polytetrafluoroethylene reinforcement of varicose autologous vein grafts in peripheral bypass surgery produces durable bypass function

ObjectiveUse of autologous veins as peripheral bypass graft may become critical in the presence of significant varicose degeneration of the harvested vein. External support of such dilated veins with standard polytetrafluoroethylene (PTFE) prostheses was recommended as an option to use these veins for peripheral bypass. A single-center experience with this technique regarding long-term graft function, secondary reinterventions, and potential graft degeneration is presented. MethodsBetween January 1995 and January 2006, there were 54 patients with varicose veins who underwent 57 consecutive infrainguinal vein bypass operations with PTFE reinforcement in 57 limbs. Indications for surgery consisted of disabling claudication (5), chronic critical ischemia (40), popliteal aneurysm (11), and acute ischemia (1). Grafts were observed with duplex ultrasound scan supplemented by additional angiography in case of recurrent ischemia, with prospective documentation of follow-up data in a computerized vascular database. Graft patency, limb salvage, and possible degeneration of the vein grafts were retrospectively analyzed. ResultsMean follow-up was 79 months (range, 1-219 months). The 30-day mortality was 2%. Secondary procedures to maintain or to restore bypass patency were necessary in 12 grafts (21%). Primary, primary assisted, and secondary patency rates were 54%, 73%, and 73% after 5 years for all bypasses, with a limb salvage rate for limbs operated on for chronic critical or acute ischemia of 83%. Significant stenosis of a reinforced vein segment was detected in one case after 56 months, with subsequent replacement of the vein graft with a biologic vascular prosthesis. ConclusionsGood late graft patency and limb salvage combined with a low rate of late vein graft degeneration justify the use of external PTFE reinforcement of varicose vein segments in infrainguinal bypass surgery.

Long-Term Tissue Culture of Adult Brain and Spleen Slices on Nanostructured Scaffolds.

Long-term tissue culture of adult mammalian organs is a highly promising approach to bridge the gap between single cell cultures and animal experiments, and bears the potential to reduce in vivo studies. Novel biomimetic materials open up new possibilities to maintain the complex tissue structure in vitro; however, survival times of adult tissues ex vivo are still limited to a few days with established state-of-the-art techniques. Here, it is demonstrated that TiO2 nanotube scaffolds with specific tissue-tailored characteristics can serve as superior substrates for long-term adult brain and spleen tissue culture. High viability of the explants for at least two weeks is achieved and compared to tissues cultured on standard polytetrafluoroethylene (PTFE) membranes. Histological and immunohistochemical staining and live imaging are used to investigate tissue condition after 5 and 14 d in vitro, while environmental scanning electron microscopy qualifies the interaction with the underlying scaffold. In contrast to tissues cultured on PTFE membranes, enhanced tissue morphology is detected in spleen slices, as well as minor cell death in neuronal tissue, both cultured on nanotube scaffolds. This novel biomimetic tissue model will prove to be useful to address fundamental biological and medical questions from tissue regeneration up to tumor progression and therapeutic approaches.

Five-year Outcomes Following a Randomized Trial of Femorofemoral and Femoropopliteal Bypass Grafting With Heparin-Bonded or Standard Polytetrafluoroethylene Grafts

Five-year Outcomes Following a Randomized Trial of Femorofemoral and Femoropopliteal Bypass Grafting With Heparin-Bonded or Standard Polytetrafluoroethylene Grafts

Initial clinical experience with a polytetrafluoroethylene vascular dialysis graft reinforced with nitinol at the venous end

ObjectiveThe purpose of this study was to examine the outcomes of a vascular hybrid polytetrafluoroethylene (PTFE) graft, provided with a nitinol-reinforced section (NRS) on one end, in hemodialysis vascular access placement. MethodsA retrospective study was conducted including all the consecutive patients who underwent Gore Hybrid Vascular Graft (GHVG; W. L. Gore & Associates, Flagstaff, Ariz) implantation for hemodialysis access placement between October 2013 and November 2015. A propensity-matched control group was obtained from consecutive patients who underwent standard PTFE arteriovenous graft implantation between January 2010 and July 2013. The selection criteria were inadequate venous material for autogenous arteriovenous fistula placement, patent deep venous circulation, and vein diameter of 4 to 8.5 mm. The implantation technique involves the insertion of the NRS some centimeters into the target vein. Fluoroscopic guidance helps deploy the device in the desired landing zone (ie, position of the proximal end of the NRS), based on anatomic landmarks. Survival, functional patency rates, and complications were compared with a propensity-matched historical control group. Vein diameter, previous vascular access placement, and diabetes were tested as predictors of reintervention with a logistic regression analysis. ResultsThere were 32 patients (14 men; mean age, 69 ± 14 years) who received the GHVG graft. The historical control group included 43 patients. Technical success was 100%. The graft configuration was brachial-axillary (n = 22 [69%]), brachial-basilic loop (n = 5 [16%]), brachial-antecubital loop (n = 3 [9%]), axilloaxillary loop (n = 1 [3%]), and femoral-femoral loop (n = 1 [3%]). Mean NRS oversize was 20% ± 7% (range, 3%-34%; median, 19%). Perioperative complications requiring revision included acute limb ischemia treated with thrombectomy (n = 1 [3%]) and graft infection requiring explantation (n = 2 [6%]). Two patients (6%) died in the hospital of unrelated causes. The mean follow-up was 15 ± 11 months (range, 0-33 months; median, 15.5). The propensity-matched groups included 25 patients each. Survival estimates at 24 months for the GHVG and standard PTFE groups were 91% ± 6% and 82% ± 9% (P > .05), respectively. The 12-month patency estimates were as follows: functional primary patency, 66% ± 10% vs 51% ± 10% (P > .05); functional assisted primary patency, 75% ± 9% vs 51% ± 10% (P > .05); and functional secondary patency, 79% ± 9% vs 67% ± 10% (P > .05). Reduction in vein diameter was associated with reintervention. ConclusionsThe GHVG is a safe and effective alternative to standard PTFE in hemodialysis access surgery. Careful planning for the landing zone is advisable, especially for small outflow veins. Larger studies and randomized trials are needed to define the role for this device. A study including a greater number of centers experienced with this device is currently under way.

THERMOELECTRIC SENSORS FOR REGISTRATION OF INTRAOCULAR TEMPERATURE

To develop thermoelectric sensors for measuring of intraocular temperature and to study temperature distribution in different parts of the rabbit eye, depending on the ambient temperature. Materials and methods. The experiment was performed on 21 rabbits (42 eyes) which were divided into 3 groups depending on the ambient temperature. For temperature measurement, the thermoelectric device was developed consisting of the module for temperature registration, the measuring probes with thermocouple sensors and the computer with software. Results. The lowest temperature was noted in the outer corneal surface, and then it increased gradually in the inner segments of the eye and reached its maximum in the retina and subtenon space. A temperature gradient between the outer corneal surface and the retina was 3.23оС, 4.68оС and 3.85оС in Group I, II and III, respectively. Conclusions. The thermoelectric probe based on L-type thermocouples in the body of a standard polytetrafluoroethylene cannula with a low thermal conductivity was designed and manufactured. The temperature distribution in the rabbit eye was studied and the existence of the temperature gradient between the different parts of the eye in the in vivo experiment was confirmed. Raising and lowering of the ambient temperature increases the temperature gradient between the external and internal structures of the rabbit eye.

Cost Effectiveness Analysis of Heparin- Versus Standard Polytetrafluoroethylene Graft alongside a Randomised Controlled Trial with Five Years Follow-Up

Cost Effectiveness Analysis of Heparin- Versus Standard Polytetrafluoroethylene Graft alongside a Randomised Controlled Trial with Five Years Follow-Up

Five-year outcomes following a randomized trial of femorofemoral and femoropopliteal bypass grafting with heparin-bonded or standard polytetrafluoroethylene grafts.

Cohort studies suggest superior long-term patency of luminal heparin-bonded polytetrafluoroethylene (Hb-PTFE) bypass grafts compared with standard PTFE grafts. The aim of this study was to compare the outcomes of Hb-PTFE grafts with those of standard PTFE grafts 5 years after a randomized trial. Patients with intermittent claudication or critical limb ischaemia requiring femorofemoral or femoropopliteal bypass grafting were randomized in a clinical trial of Hb-PTFE versus standard PTFE in 11 Scandinavian centres between 2005 and 2009. Patients were followed up for 5 years with clinical assessment and surveillance Duplex ultrasound imaging. The primary endpoint of this study was primary patency. Secondary endpoints included major amputation and mortality. Overall, 569 patients were enrolled in the randomized trial. Some 552 had follow-up data available for analysis of the primary outcome. Use of Hb-PTFE significantly improved patency by 37 per cent at 2 years, but 5 years after randomization there was no difference in primary patency (adjusted hazard ratio (HR) 0·95, 95 per cent c.i. 0·71 to 1·28; P = 0·748). In patients with critical limb ischaemia the use of Hb-PTFE reduced the 5-year risk of loss of primary patency by 37 per cent (HR 0·63, 0·40 to 0·99; P = 0·049). In this study there was no difference in primary graft patency between Hb-PTFE and standard PTFE grafts. Patients receiving Hb-PTFE grafts for critical limb ischaemia were more likely to have a patent graft at 5 years than those with standard PTFE grafts.

Equivalent outcomes with standard and heparin-bonded expanded polytetrafluoroethylene grafts used as conduits for hemodialysis access

Obtaining and maintaining dialysis access after failure of autologous access sites remains a significant concern for patients on hemodialysis. Polytetrafluoroethylene (PTFE) is the most common conduit used. Heparin-bonded expanded PTFE (HB-PTFE) grafts have recently been introduced as an improved conduit, with suggestions that HB offers benefits because of its resistance to thrombosis. In this retrospective study, the outcomes of HB-PTFE were compared with standard wall PTFE (S-PTFE) arteriovenous grafts (AVGs). From January 2004 to December 2014, 483 adults (46% male; mean age, 60years; range, 25-87years) with end-stage renal disease underwent placement of AVGs (234 HB-PTFE and 248 S-PTFE). The two groups did not differ significantly in demographics or access history. Patency, reintervention, infection, and functional dialysis rates were examined. Technical success was 99% in HB-PTFE and 98% in S-PTFE. The 30-day major adverse cardiovascular events were 2% in HB-PTFE and 3% in S-PTFE. Mean time to access was 5.1± 1.8weeks for HB-PTFE and 6.9± 1.9weeks for S-PTFE (P= .0001). Median follow-up was 23months. The 2-year primary, assisted primary, and secondary patency rates were 20%± 7% vs 18%± 8% (P= .85), 35%± 8% vs 28%± 7% (P= .51), and 38%± 6% vs 36%± 7% (P= .83) for HB-PTFE vs S-PTFE, respectively. Both groups underwent a similar number of secondary interventions (2.1 and 1.9 interventions per person-year of follow-up for HB-PTFE vs S-PTFE respectively; P= .87). There were no significant differences in infection (11% vs 12%) or pseudoaneurysm formation (5% vs 6%) between HB-PTFE and S-PTFE groups. Functional dialysis durations were equivalent between HB-PTFE and S-PTFE groups. HB-PTFE grafts offer no distinct advantage over S-PTFE grafts for hemodialysis and should not be considered a preferential conduit for AVG.

Early Experience With a Novel Hybrid Vascular Graft for Hemodialysis Access Creation in Patients With Disadvantaged Anatomy

Purpose: To describe the use of the Hybrid vascular graft in disadvantaged anatomy for hemodialysis access creation and compare outcomes to standard-wall polytetrafluoroethylene (PTFE) grafts. Methods: In a retrospective analysis, 25 patients (mean age 65±14 years; 13 men) who received the Hybrid graft were compared with 35 contemporaneous patients (mean age 63±12 years; 20 men) who received a standard PTFE graft for hemodialysis access over a 2-year period. Criteria for Hybrid graft placement were (1) exhausted or inadequate peripheral veins for arteriovenous fistula (AVF) creation and concomitant small target veins that precluded conventional PTFE graft placement, (2) previous graft anastomosis or a stent in the venous target at the level of the axilla, or (3) failed brachial-basilic or brachial-brachial upper arm transposition AVF with a small target vein at the axilla. Efficacy, anatomic and clinical considerations, and technique were reviewed; patency rates, complications, and reinterventions were examined. Results: Technical success was achieved in all cases, and all grafts were usable for hemodialysis. Seven of 25 Hybrid patients required stent-graft extensions and 3 patients required angioplasty to improve venous outflow at the time of Hybrid graft insertion. Three of 35 standard PTFE graft patients required angioplasty to improve venous outflow at the time of graft insertion. There was no perioperative mortality or procedure-related morbidity in either group. Median follow-up was 21 months. The patient survival estimate was 66% at 2 years. Estimated primary patency (24% vs 18%, p>0.05), assisted primary patency (34% vs 28%; p>0.05), and secondary patency rates (40% vs 38%, p≥0.05) at 24 months were equivalent for Hybrid vs PTFE grafts, respectively. Venous hypertension was not a complication following Hybrid graft implantation but was seen in 2 patients with the standard PTFE graft. Conclusion: The Hybrid graft offers a safe, technically effective alternative for patients with disadvantaged anatomy requiring hemodialysis access and has comparable outcomes to standard PTFE grafts. Further clinical experience and long-term data are required for determining the proper utility of this device in chronic dialysis-dependent patients.

Types of indwelling urethral catheters for short-term catheterisation in hospitalised adults.

Types of indwelling urethral catheters for short-term catheterisation in hospitalised adults.

Early cannulation prosthetic graft (Acuseal) for arteriovenous access: a useful option to provide a personal vascular access solution.

Early cannulation arteriovenous grafts (ecAVGs), such as the GORE Acuseal, have "low bleed" properties permitting cannulation within 24 hours of insertion. They may provide an alternative to tunneled central venous catheters (and associated line complications) in patients requiring urgent vascular access. We present our early experience of 37 patients treated with the GORE Acuseal ecAVG. A total of 11 upper limb, 24 lower limb and 2 complex graft procedures were performed. Indications for ecAVG were as follows: bridge to transplantation (21.6%); bridge to arteriovenous fistula (AVF) maturation (8.1%); AVF salvage (8.1%); no native options (67.6%, including 17 patients with bilateral central vein stenosis); 36 AVGs (97.3%) were successfully cannulated. Mean time to first cannulation: 30.4±23.4 hours (range: 2-192). Primary and secondary patency rates at 3, 6 and 12 months were 64.9%, 48.6%, 32.4% and 70.2%, 59.4%, 40.5% respectively. The systemic bacteremia rate was 0.2 per 1,000 access days. There was one perioperative death. Other complications included hematoma at cannulation sites (n=9), pseudoaneurysm (n=3) and local infection at graft site (n=6). A total of 26 of 37 patients (70.6%) achieved a "personal vascular access solution": bridge to transplantation (n=8), bridge to functioning AVF/interposition AVG (n=5), maintenance hemodialysis via ecAVG (n=13); death with functioning AVG (n=1). Early experience with the GORE Acuseal is encouraging. Patency and bacteremia rates are at least comparable to standard polytetrafluoroethylene grafts. ecAVGs have permitted cannulation within 24 hours of insertion and line avoidance in the majority of patients. Nearly three-quarters of patients achieved a definitive "personal vascular access solution" from their ecAVG.

Cost Effectiveness of Antimicrobial Catheters for Adults Requiring Short-term Catheterisation in Hospital

Catheter-associated urinary tract infection (CAUTI) is the second most common cause of hospital-acquired infection. A number of strategies have been put forward to prevent CAUTI, including the use of antimicrobial catheters. We aimed to assess whether the use of either a nitrofurazone-impregnated or a silver alloy–coated catheter was cost-effective compared with standard polytetrafluoroethylene (PTFE)–coated catheters. A decision-analytic model using data from a clinical trial conducted in the United Kingdom was used to calculate the incremental cost per quality-adjusted life-year (QALY). We assumed that differences in costs and QALYs were driven by difference in risk of acquiring a CAUTI. Routine use of nitrofurazone-impregnated catheters was, on average, £7 (€9) less costly than use of the standard catheter over 6 wk. There was a >70% chance that use of nitrofurazone catheters would be cost saving and an 84% chance that the incremental cost per QALY would be less than £30 000 (€36 851; a commonly used threshold for society's willingness to pay). Silver alloy–coated catheters were very unlikely to be cost-effective. The model's prediction, although associated with uncertainty, was that nitrofurazone-impregnated catheters may be cost-effective in the UK National Health System or a similar setting.

Comparison of Flixene™ and Standard PTFE Arteriovenous Graft for Early Haemodialysis

The purpose is to compare the outcomes of FLIXENE™ arteriovenous graft (AVG) to standard polytetrafluoroethylene (PTFE) AVG for early haemodialysis. This is a prospective observational study of all AVGs placed over a 40-month period between 2008 and 2011 at our vascular unit. Primary outcome was to examine early cannulation rates for FLIXENE™. Secondary outcomes included patency rates, usability of grafts, complications in particular infections, interventions and death in comparison to standard PTFE grafts. Forty-five FLIXENE™ and 19 standard PTFE AVGs were placed in the study period; 89% of FLIXENE™ grafts were used for dialysis, with 78% cannulated within 3 days. At 18 months, primary patency (FLIXENE™ 34% vs standard PTFE 24%), primary assisted patency (35% vs 36%) and secondary patency rate (51% vs 48%) were not statistically different; 20.2% of FLIXENE™ grafts were infected at 18 months requiring explantation compared with 40.3% of standard PTFE grafts (p=0.14). FLIXENE™ can be cannulated for dialysis within 3 days. It has similar patency and complication rates as other prosthetic grafts in the market. In patients who have no access and require urgent dialysis, FLIXENE™ is a viable option.