Increased Risk of Infection Associated with Polyurethane Dialysis Grafts

Outcomes of early cannulation arteriovenous graft versus PTFE arteriovenous graft in hemodialysis patients: A meta-analysis and systematic review

Arteriovenous graft (AVG) is an alternative for hemodialysis (HD) patients with end-stage renal disease when their permanent vascular accesses fail. Since the last decades, the most widely used materials in these patients have been polytetrafluoroethylene (PTFE)-AVGs. Recently, several studies have reported that early cannulation (EC)-AVG can be an alternative to PTFE-AVG. This systematic review and meta-analysis aimed to compare the outcomes of EC-AVG and PTFE-AVG in HD patients. We searched the Ovid Embase, Ovid MEDLINE, and Cochrane Central Register of Controlled Trials for the relevant studies published from 01.01.2000 to 19.12.2022 by keywords and free words. All randomized controlled trials (RCTs) and observational cohort studies comparing EC-AVG with PTFE-AVG were included. Ten studies were included in analysis: one RCT, six retrospective cohort studies, and three prospective cohort studies. The results showed shorter cannulation intervals (four studies, 1116 participants: mean difference -23.62 days, 95% CI [-32.03, -15.21], p < 0.05) and less central venous catheter (CVC) usage (four studies, 733 participants: OR 0.20, 95% CI [0.04, 0.92], p < 0.05) for EC-AVG compared with PTFE-AVG, while comparable outcomes of primary patency (eight studies, 1712 participants: HR 0.89, 95% CI [0.70, 1.12]), primary assisted patency (five studies, 1355 participants: HR 1.13, 95% CI [0.70, 1.84]), secondary patency (nine studies, 1920 participants: HR 0.93, 95% CI [0.66, 1.31]), and infection risk (four studies, 640 participants: HR 1.12, 95% CI [0.48, 2.58]). When compared to PTFE-AVG in HD patients, EC-AVG seems to exhibit shorter cannulation intervals, less CVC usage, and comparable outcomes of graft patency, and infection risk.

Diamond-like carbon coating to inner surface of polyurethane tube reduces Staphylococcus aureus bacterial adhesion and biofilm formation

Staphylococcus aureus is one of the main causative bacteria for polyurethane catheter and artificial graft infection. Recently, we developed a unique technique for coating diamond-like carbon (DLC) inside the luminal resin structure of polyurethane tubes. This study aimed to elucidate the infection-preventing effects of diamond-like carbon (DLC) coating on a polyurethane surface against S. aureus. We applied DLC to polyurethane tubes and rolled polyurethane sheets with our newly developed DLC coating technique for resin tubes. The DLC-coated and uncoated polyurethane surfaces were tested in smoothness, hydrophilicity, zeta-potential, and anti-bacterial properties against S. aureus (biofilm formation and bacterial attachment) by contact with bacterial fluids under static and flow conditions. The DLC-coated polyurethane surface was significantly smoother, more hydrophilic, and had a more negative zeta-potential than did the uncoated polyurethane surface. Upon exposure to bacterial fluid under both static and flow conditions, DLC-coated polyurethane exhibited significantly less biofilm formation than uncoated polyurethane, based on absorbance measurements. In addition, the adherence of S. aureus was significantly lower for DLC-coated polyurethane than for uncoated polyurethane under both conditions, based on scanning electron microscopy. These results show that applying DLC coating to the luminal resin of polyurethane tubes may impart antimicrobial effects against S. aureus to implantable medical polyurethane devices, such as vascular grafts and central venous catheters.

Experimental Study on the Cement-Based Materials Used in Coal Mine Gas Extraction for Hole Sealing

Gas drainage is an important method to prevent and control gas disasters. Sealing materials have an important impact on the gas drainage effect. To improve the extraction rate, the configuration and related characteristics of sealing materials were studied in this study. It was found that the fluidity increased gradually with the increase of the dosage of the suspension concentrate (SC). The water-cement ratio was directly proportional to the setting time of the slurry. Also, the mixing amount of the special cement was inversely proportional to the setting time of the slurry. The influence of the amount of foaming agent, special cement, and suspending agent on the expansion rate of the slurry was positive, and the influence gradually weakened. When the water-cement ratio of cement-based materials was 0.6, the special cement content percentage was 6, the suspension agent content percentage was 3, the plasticizer content percentage was 0.7, the early strength agent content percentage was 1.2, and the foaming agent content percentage was 0.2, the sealing effect was the best. The research results suggest that the porosity and pore length of the cement-based material are smaller than those of polyurethane, and its sealing property was better. This could further increase the sealing effect of the gas borehole, thereby facilitating gas extraction.

Long-term outcomes of anterior chest wall arteriovenous graft with polyurethane

BACKGROUND

Anterior chest wall arteriovenous graft (ACWAVG) is one option for haemodialysis patients when vessels of the upper extremities become exhausted. We report here the long-term outcomes of ACWAVG with polyurethane.

METHODS

From April 2005 to October 2015, nine ACWAVGs with polyurethane grafts were created. We observed patients until April 2019 and evaluated graft patency, interval from operation to first cannulation, and numbers of interventions and complications.

RESULTS

Primary patency rate and secondary patency rate of 6, 12 and 24 months were 55.3%, 33.3%, 33.3% and 77.8%, 55.6%, 55.6% respectively. Mean interval from operation to first cannulation was 3 days. Infection rate and kinking formation rate were slightly higher than previous reports of ACWAVGs with expanded polytetrafluoroethylene (ePTFE). However, one patient was able to keep using a single graft for 166 months with multiple interventions.

CONCLUSIONS

Slight disadvantage are seen with patency rate and complication rate in polyurethane ACWAVG compare to ePTFE. However, when early cannulation is required, polyurethane is worth to consider for creating ACWAVG.

Traditional versus Early-access Grafts for Hemodialysis Access: A Single-institution Comparative Study

In those patients requiring urgent hemodialysis, the use of early-access grafts may reduce the need for temporary hemodialysis catheters and their resultant complications such as infection and central venous stenosis. We review a consecutive group of patients undergoing placement of a traditional polytetrafluoroethylene (PTFE) graft as compared with a cohort of patients who underwent insertion of a trilaminate PTFE vascular graft (TPVG). During the period from January 2008 to December 2009, 65 sequential patients received a traditional PTFE graft with 78 subsequent patients having a TPVG inserted. Factors examined included use of temporary hemodialysis catheters during the period of graft maturation, incidence of infection, and primary and secondary graft patency. For all patients, incidence was reported as observed during the first year after graft insertion. With the use of the TPVG, need for temporary hemodialysis catheters was reduced from 91 to 32 per cent, and 1-year overall graft patency was improved from 36 to 77 per cent ( P < 0.01). We report that the use of a trilaminate PTFE graft allowed early access, reduced the need for temporary hemodialysis catheters, decreased overall graft complication rates, and significantly improved 1-year patency.

Clopidogrel eluting electrospun polyurethane/polyethylene glycol thromboresistant, hemocompatible nanofibrous scaffolds

Biomaterials used as blood-contacting material must be hemocompatible and exhibit lower thrombotic potential while maintaining hemostasis and angiogenesis. With the aim of developing thromboresistant, hemocompatible nanofibrous scaffolds, polyurethane/polyethylene glycol scaffolds incorporated with 1, 5, and 10 wt% Clopidogrel were fabricated and evaluated for their physiochemical properties, biocompatibility, hemocompatibility, and antithrombotic potential. The results of physicochemical characterization revealed the fabrication of nanometer-sized scaffolds with smooth surfaces. The incorporation of both polyethylene glycol and Clopidogrel to polyurethane enhanced the hydrophilicity and water uptake potential of polyurethane/polyethylene glycol/Clopidogrel scaffolds. The dynamic mechanical analysis revealed the enhancement in mechanical strength of the polyurethane/polyethylene glycol scaffolds on incorporation of Clopidogrel. The polyurethane/polyethylene glycol/Clopidogrel scaffolds showed a tri-phasic drug release pattern. The results of hemocompatibility assessment demonstrated the excellent blood compatibility of the polyurethane/polyethylene glycol/Clopidogrel scaffolds, with the developed scaffolds exhibiting lower hemolysis, increased albumin and plasma protein adsorption while reduction in fibrinogen adsorption. Further, the platelet adhesion was highly suppressed and significant increase in coagulation period was observed for Clopidogrel incorporated scaffolds. The results of cell adhesion and cell viability substantiate the biocompatibility of the developed nanofibrous scaffolds with the HUVEC cell viability on polyurethane/polyethylene glycol, polyurethane/polyethylene glycol/Clopidogrel-1, 5, and 10% at day 7 found to be 12.35, 13.36, 14.85, and 4.18% higher as compared to polyurethane scaffolds, and the NIH/3T3 cell viability found to be 35.27, 70.82, 36.60, and 7.95% higher as compared to polyurethane scaffolds, respectively. Altogether the results of the study advocate the incorporation of Clopidogrel to the polyurethane/polyethylene glycol blend in order to fabricate scaffolds with appropriate antithrombotic property, hemocompatibility, and cell proliferation capacity and thus, might be successfully used as antithrombotic material for biomedical application.

Long-Term Results of PTFE Grafts

Vascular surgeons are essential in “lifeline” creation for hemodialysis patients and should be the central player in any multidisciplinary access service together with nephrologists, dialysis staff and interventional radiology. In this position, access surgeons are involved in complicated clinical decision making regarding primary and secondary access selection, which throughout the last decade has been largely aided, and influenced, by national and international guidelines as well as other initiatives. These recommendations, unanimously and appropriately, advocate the placement of native fistulas over synthetic grafts (the majority grafts from expanded polytetrafluoroethylene, ePTFE, herein referred to as PTFE) based on the superiority of fistulas with respect to complications such as infections and thrombosis. Nevertheless, the use of PTFE grafts for hemodialysis access is an accepted and firmly established alternative to native fistulas where data today reveal unwanted consequences to overinterpretation of established guidelines such as increased catheter use. This information highlights a need for an adjustment of access selection strategies based on patient-centered algorithms. Here, available results on PTFE graft performance in hemodialysis access is recapitulated, with respect to both conventional grafts and technical modifications, and conclude with a modified approach to primary access selection.

A Patient with Recurrent Arteriovenous Graft Thrombosis

Arteriovenous grafts (AVGs) are prone to frequent thrombosis that is superimposed on underlying hemodynamically significant stenosis, most commonly at the graft-vein anastomosis. There has been great interest in detecting AVG stenosis in a timely fashion and performing preemptive angioplasty, in the belief that this will prevent AVG thrombosis. Three surveillance methods (static dialysis venous pressure, flow monitoring, and duplex ultrasound) can detect AVG stenosis. Whereas observational studies have reported that surveillance with preemptive angioplasty substantially reduces AVG thrombosis, randomized clinical trials have failed to confirm such a benefit. There is a high frequency of early AVG restenosis after angioplasty caused by aggressive neointimal hyperplasia resulting from vascular injury. Stent grafts prevent AVG restenosis better than balloon angioplasty, but they do not prevent AVG thrombosis. Several pharmacologic interventions to prevent AVG failure have been evaluated in randomized clinical trials. Anticoagulation or aspirin plus clopidogrel do not prevent AVG thrombosis, but increase hemorrhagic events. Treatment of hyperhomocysteinemia does not prevent AVG thrombosis. Dipyridamole plus aspirin modestly decreases AVG stenosis or thrombosis. Fish oil substantially decreases the frequency of AVG stenosis and thrombosis. In patients who have exhausted all options for vascular access in the upper extremities, thigh AVGs are a superior option to tunneled internal jugular vein central vein catheters (CVCs). An immediate-use AVG is a reasonable option in patients with recurrent CVC dysfunction or infection. Tunneled femoral CVCs have much worse survival than internal jugular CVCs.

Use of the Flixene vascular access graft as an early cannulation solution

OBJECTIVE

The primary end points of this study were safety and efficacy of early cannulation of the Flixene graft (Maquet-Atrium Medical, Hudson, NH). Secondary end points were complications and patency.

METHODS

This is a prospective single-center nonrandomized study. Study data included patient characteristics; history of vascular access; operative technique; interval between implantation and initial cannulation; complications; and patency at 1 month, 3 months, and every 6 months. Patency rates were estimated by the Kaplan-Meier method.

RESULTS

Between January 2011 and September 2013, a total of 46 Flixene grafts were implanted in 44 patients (27 men) with a mean age of 63 years. The implantation site was the upper arm in 67% of cases, the forearm in 11%, and the thigh in 22%. Seven grafts were never cannulated during the study period. Of the remaining 39 grafts, 32 (82%) were successfully cannulated within the first week after implantation, including 16 (41%) on the first day. The median interval from implantation to initial cannulation was 2 days (interquartile range, 1-3 days). The median follow-up was 223.5 days (interquartile range, 97-600 days). Five hematomas occurred, but only one required surgical revision. Primary assisted and secondary patency rates were 65% and 86%, respectively, at 6 months and 56% and 86%, respectively, at 1 year.

CONCLUSIONS

This study suggests that cannulation of the Flixene graft within 1 week after implantation is safe and effective. Early cannulation avoids or shortens the need for a temporary catheter. One-year patency rates appeared to be comparable to those achieved with conventional grafts, but long-term follow-up and randomized controlled studies will be needed to confirm this finding.

Biomaterial applications in cardiovascular tissue repair and regeneration

Cardiovascular disease physically damages the heart, resulting in loss of cardiac function. Medications can help alleviate symptoms, but it is more beneficial to treat the root cause by repairing injured tissues, which gives patients better outcomes. Besides heart transplants, cardiac surgeons use a variety of methods for repairing different areas of the heart such as the ventricular septal wall and valves. A multitude of biomaterials are used in the repair and replacement of impaired heart tissues. These biomaterials fall into two main categories: synthetic and natural. Synthetic materials used in cardiovascular applications include polymers and metals. Natural materials are derived from biological sources such as human donor or harvested animal tissues. A new class of composite materials has emerged to take advantage of the benefits of the strengths and minimize the weaknesses of both synthetic and natural materials. This article reviews the current and prospective applications of biomaterials in cardiovascular therapies.

Early Experience with a Newly Developed Electrospun Polycarbonate-urethane Vascular Graft for Hemodialysis Access

Purpose

In this pilot study, we tested a newly developed electrospun multilayered, self-sealing graft, AVflo™, specifically designed for early hemodialysis access.

Methods

Ten eligible consenting patients had a polycarbonate-urethane graft (AVflo™) implanted and were followed up prospectively for at least six months. Performance measures included graft patency, complications and time to first cannulation. Mean age of the patients was 66.7 ± 10 years. Chronic glomerulonephritis was the most common cause of renal failure. A total of 70% of the patients had a history of previous vascular access and 40% history of minimally invasive radiologic procedures for patency maintenance. In 40% of the cases the need for AV graft implantation was because of recurrent infections from permanent catheter for dialysis. Seven grafts were placed in the upper arm and three in the thigh. Mean follow up was 230 ± 75 days.

Results

There were no systemic or local reactions to the graft and we did not report any graft infections. Two grafts thrombosed because of severe bleeding post-cannulation due to an incorrect needle puncture. Both grafts were successfully thrombectomized. Primary and secondary patency rates at six months were 60% and 78%, respectively. These patency rates were comparable to those reported for other polyether-urethane and ePTFE grafts. Median time to first cannulation was seven days (3-21) and all puncture sites sealed in less than five minutes.

Conclusions

This newly developed electrospun polycarbonate-urethane graft is safe in humans, permits early access obviating the need for venous catheters, and has equivalent patency as other prosthetic grafts.

Use of Hybrid Vascular Grafts in Failing Access for Hemodialysis: Report of Two Cases

Purpose

Vascular access morbidity represents one of the most common indications for readmission in patients with end-stage renal disease (ESRD). We report the use of hybrid grafts in two patients for revision of failed vascular access for hemodialysis (HD).

Case Presentations

The first patient was a 45-year-old woman with ESRD who presented with an arteriovenous graft (AVG) that had required multiple interventions for maintenance in whom much of the graft was lined with covered stents. The patient presented with erosion of a stent in the AVG through the skin to the emergency department. The second patient was a 41-year-old man with ESRD who also had an AVG that had required multiple interventions for maintenance. He presented to clinic with chronic bleeding from the AVG after HD sessions. Both patients were taken to the operating room for salvage of part of the AVG through the use of hybrid vascular access grafts. The patients have passed six and three months from the procedure, respectively, without needing additional interventions.

Conclusions

This technique demonstrates successful use of hybrid vascular access grafts, specifically inside existing grafts in locations that contain stents utilizing the existing venous resources in that arm to carry out the surgical repair, thereby preserving venous capital.

Antimicrobial prophylaxis in noncardiac prosthetic device recipients

BACKGROUND

Secondary antimicrobial prophylaxis involves the use of ≥ 1 antimicrobial agent just prior to the time when a diagnostic/therapeutic procedure, which may induce infection, is to be performed. In the context of this article, antimicrobial agent(s) are administered to patients with ≥ 1 implanted prosthetic device in order to prevent metastatic seeding of the device(s) during bacteremia induced by a diagnostic/therapeutic procedure. Antimicrobial agents used in this context are only administered periprocedurally. Secondary antimicrobial prophylaxis of endocarditis in recipients of cardiac prosthetic materials (including valves, shunts, conduits, and patches) has been reasonably well established. However, secondary antimicrobial prophylaxis in recipients of other types of prosthetic devices has been the subject of much controversy, with a wide variety of recommendations being made.

OBJECTIVES

The purpose of this article was to conduct a narrative review of the published literature on the topic of secondary antimicrobial prophylaxis in recipients of noncardiac prosthetic devices and make evidence-based recommendations for each type of device, where possible.

METHODS

Medline/PubMed and EMBASE databases were searched for English-language articles published from 1950 to the present (January 2012). Search terms included "prophylaxis," "antibiotics," "antimicrobials," "prosthetic devices," "prosthesis-related infections," "bacteremia," the names of the individual types of prosthetic devices, and the names of the individual procedures potentially inducing bacteremia. Articles dealing with any aspect relevant to this topic were eligible for review. The bibliographies of retrieved articles were also carefully scanned to identify any articles not previously identified.

RESULTS

Based on review of the available literature, secondary antimicrobial prophylaxis is justified in only a few specific circumstances. For recipients of prosthetic vascular grafts/stents, hemodialysis arteriovenous shunts, and ventriculoatrial/ventriculovenous shunts, prophylaxis is warranted during the initial 6 months, initial 6 weeks, and at all times after implantation/revision, respectively, when dental procedures capable of inducing high-level bacteremia are planned. Prosthetic joint recipients should receive prophylaxis in the following 3 circumstances: 1) patient is to undergo dental procedure(s) capable of inducing high-level bacteremia plus either the patient is still within 2 years of device implantation/revision or the patient has ≥ 1 risk factor for hematogenous prosthetic joint infection; 2) patient is to undergo genitourinary tract procedure(s) capable of inducing high-level bacteremia plus the patient has ≥ 1 risk factor for high-risk bacteriuria; and 3) patient is to undergo perforating dermatologic surgery on the oral mucosa or at skin sites at increased risk for surgical site infection plus patient has ≥ 1 risk factor for hematogenous prosthetic joint infection. The data are inadequate to justify secondary antimicrobial prophylaxis for recipients of other types of prosthetic devices. On the basis of 9 surveys of prescriber behavior, it is apparent that there exists, over a wide geographic area, a wide disconnect between clinical practice and the secondary antimicrobial prophylaxis guidelines issued by the professional organizations representing these prescribers. Antimicrobial agent overuse was especially problematic among orthopedic and colorectal surgeons, urologists, and family practitioners. Dentists and maxillofacial surgeons followed guidelines more closely.

CONCLUSION

Device-, procedure-, and patient characteristic-dependent factors elicited over many years have narrowed down the secondary antimicrobial prophylaxis recommendations for noncardiac prosthetic devices to a small number. Despite this, physician prescribers frequently do not follow prophylaxis guidelines established by their own professional organizations. Risk-benefit and cost-effectiveness studies have found that no prophylaxis is actually superior to universal prophylaxis, likely due to known antimicrobial toxicities, such as anaphylactic/anaphylactoid reactions and Clostridium difficile-associated disease. Much work remains in establishing and extending the scientific basis for secondary antimicrobial prophylaxis and transforming this knowledge into appropriate action by the clinician.

Development of bacterially resistant polyurethane for coating medical devices

Polyurethanes have been widely used in medicine for coating and packaging implantable and other medical devices. Polyether-urethanes, in particular, have superior mechanical properties and are biocompatible, but in common with other medical materials they are susceptible to microbial film formation. In this study, polyether-urethane was end-capped with silver lactate and silver sulfadiazine functional groups to produce a bacterially resistant polymer without sacrificing the useful mechanical properties of the polyether-polyurethane. The silver ions were covalently incorporated into the polymer during chain extension of the prepolymer. The functionalized polymers were structurally characterized by light scattering, electron microscopy, NMR, FTIR and Raman spectroscopy. Mechanical properties, hydrophilicity, in vitro stability and antibacterial action of polymers were also investigated. Results indicate that both silver salts were successfully incorporated into the polymer structure without significant effect on mechanical properties, whilst conferring acceptable bacterial resistance.

Long-term complication and patency rates of Vectra and IMPRA Carboflo Vascular Access Grafts with aggressive monitoring, surveillance and endovascular management

The purpose of this study is to compare infection, pseudoaneurysm formation and patency rates during long-term follow-up of polyurethane and polytetrafluoroethylene (PTFE) vascular access grafts maintained with contemporary endovascular methods. During a 34-month period, 239 polyurethane and 125 carbon-impregnated PTFE vascular access grafts were placed in 324 consecutive patients. Thirty-six patients (9.9%) developed a pseudoaneurysm (anastomotic, n = 6 or at the needle-stick site, n = 30). An additional 19 patients (5.2%) required graft excision for infection. Three-year graft infection and pseudoaneurysm formation (at needle-stick site) rates were similar in polyurethane and PTFE grafts (11% versus 8%, P = 0.61, and 17% versus 23%, P = 0.72, respectively). Three-year secondary patency was better in polyurethane than PTFE grafts (69% versus 57%, respectively, P = 0.012). Straight upper arm polyurethane grafts had the best secondary patency ( P = 0.001). Contemporary long-term secondary patency of vascular access grafts is satisfactory. Further follow-up is necessary to compare late infection and pseudoaneurysm formation rates.

The longevity of arteriovenous graft for hemodialysis patients--externally supported or nonsupported

BACKGROUND AND OBJECTIVES

Because thrombosis and stenosis are the most frequent causes of arteriovenous graft (AVG) failure, several externally supported grafts were designed to enhance incompressibility and kinking resistance to improve the patency. However, consensus on advantage of these modifications having still not been reached might relate to the previous limited patient numbers and small studies. This study analyzed the longevity of externally supported and nonsupported AVG on the basis of the nationwide database to understand whether the externally supported design could improve the duration of patency of AVG.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Adult incident patients (n = 4402) were retrospectively enrolled who had began hemodialysis between January 1, 2002 and December 31, 2005. All incident patients with AVG, before or after beginning regular hemodialysis, between January 1, 2000 and December 31, 2006 were identified. The Cox proportional hazard model was used to compare the longevity of externally supported and nonsupported AVG by controlling other covariates.

RESULTS

There were 990 patients with externally supported AVG and 3412 patients with nonsupported AVG. The patency rates of externally supported AVG were 49.4%, 31.6%, and 20.2% at 1, 2 and 3 years, respectively; those of nonsupported AVG were 31.9%, 17.4%, and 10.8%. The survival of nonsupported AVG was significantly inferior to that of externally supported AVG.

CONCLUSIONS

Externally supported AVG are superior to nonsupported AVG for long-term patency. The incompressibility and kinking resistance of ringed grafts may shed light on a direction for the future development of dialysis graft design.

Significant correlation between ankle-brachial index and vascular access failure in hemodialysis patients

BACKGROUND AND OBJECTIVES

Vascular access failure (VAF) is associated with increased morbidity and mortality in hemodialysis patients. The most common cause of VAF is stenosis at the arteriovenous anastomosis because of abnormal neointimal proliferation and extracellular matrix deposition. These two changes are also observed in the classic atheroma, which means atherosclerotic lesions and venous stenosis in VAF may share some similar pathogenic mechanisms. The ankle-brachial index (ABI) is a reliable marker for atherosclerosis. The aim of this study was to evaluate the relationship between ABI <0.9 and VAF.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

All routine hemodialysis patients in one regional hospital were included except for six patients refusing ABI examinations and four patients with atrial fibrillation. Finally, 225 patients formed our study group. The study subjects were observed from arteriovenous access creation until the first episode of VAF. The mean observation period was 42.2 +/- 42.8 mo. The relative VAF risk was analyzed by Cox-regression methods with adjustments for demographic and comorbid conditions.

RESULTS

VAF episodes were recorded in 111 patients. In multivariate analysis, ABI <0.9 (hazard ratio, 1.893; P = 0.039), vascular access type of arteriovenous graft (P = 0.004), and serum triglyceride level (P = 0.043) were positively associated with VAF, and serum parathyroid hormone level (P = 0.043) was negatively associated with VAF.

CONCLUSIONS

Our findings show that ABI <0.9 is significantly correlated with increased VAF. Screening hemodialysis patients by means of ABI may help to identify a high-risk group for VAF.