Associations between hemodialysis access type and clinical outcomes: a systematic review

Successful Management of Acute Liver Failure Patients Waiting for Liver Transplantation by On-Line Hemodiafiltration with an Arteriovenous Fistula

On-line hemodiafiltration (OLHDF) is one of the treatment options in the management of acute liver failure (ALF) in Japan. It is essential to avoid infection in the management of ALF. In fact, infection is one of the prognostic factors in ALF. In this report, we present a middle-aged Japanese man with ALF associated with benzbromarone use. He was successfully managed without infection until liver transplantation by creating an arteriovenous fistula for OLHDF. Utilizing an arteriovenous fistula for OLHDF, rather than inserting a vascular access catheter, is a beneficial option to avoid infectious diseases in the management of ALF.

Tunnelled haemodialysis catheter and haemodialysis outcomes: a retrospective cohort study in Zagreb, Croatia

OBJECTIVES

Studies have reported that the tunnelled dialysis catheter (TDC) is associated with inferior haemodialysis (HD) patient survival, in comparison with arteriovenous fistula (AVF). Since many cofactors may also affect survival of HD patients, it is unclear whether the greater risk for survival arises from TDC per se, or from associated conditions. Therefore, the aim of this study was to determine, in a multivariate analysis, the long-term outcome of HD patients, with respect to vascular access (VA).

DESIGN

Retrospective cohort study.

PARTICIPANTS

This retrospective cohort study included all 156 patients with a TDC admitted at University Hospital Merkur, from 2010 to 2012. The control group consisted of 97 patients dialysed via AVF. The groups were matched according to dialysis unit and time of VA placement. The site of choice for the placement of the TDC was the right jugular vein. Kaplan-Meier analysis with log-rank test was used to assess patient survival. Multivariate Cox regression analysis was used to determine independent variables associated with patient survival.

PRIMARY OUTCOME MEASURES

Patient survival with respect to VA.

RESULTS

The cumulative 1-year survival of patients who were dialysed exclusively via TDC was 86.4% and of those who were dialysed exclusively via AVF, survival was 97.1% (p=0.002). In multivariate Cox regression analysis, male sex and older age were independently negatively associated with the survival of HD patients, while shorter HD vintage before the creation of the observed VA, hypertensive renal disease and glomerulonephritis were positively associated with survival. TDC was an independent risk factor for survival of HD patients (HR 23.0, 95% CI 6.2 to 85.3).

CONCLUSION

TDC may be an independent negative risk factor for HD patient survival.

Systematic Review of Drug Eluting Balloon Angioplasty for Arteriovenous Haemodialysis access Stenosis

Background

Native or prosthetic arteriovenous (AV) fistulas are preferred for permanent haemodialysis (HD) access. These are marked with circuit steno-occlusive disease leading to dysfunction or even failure. Late failure rates have been reported as high as 50%. Standard angioplasty balloons are an established percutaneous intervention for HD access stenosis. Reported restenosis rates remain high and practice guidelines recommend a wide 6-month primary patency (PP) of at least 50% for any intervention. Neointimal hyperplasia is one of the main causes for access circuit stenosis. Drug eluting balloon (DeB) angioplasty has been proposed as an alternative intervention to reduce restenosis by local drug delivery and possible inhibition of this process.

Purpose

To systematically assess the reported efficacy and safety of DeB angioplasty in percutaneous management of prosthetic and autologous HD access stenosis.

Methods

Protocol for the review was developed following the PRISMA-P 2015 statement. An electronic database (Medline, EMBASE, Clinical Trials.gov and Cochrane CENTRAL) search was conducted to identify articles reporting on the use of DeB intervention in HD AV access. Backward and forward citation search as well as grey literature search was performed. The MOOSE statement and PRISMA 2009 statement were followed for the reporting of results. Data from the included studies comparing DeBs with non-DeBs were pooled using a random effects metaanalysis model and reported separately on randomised and non-randomised studies.

Results

Six studies reported on 254 interventions in 162 participants (mean 27 ± 10 SD). The pooled mean and median duration of follow-up was 12 and 13 months (range 6-24 months). These comprised two randomised control trials (RCTs) and four cohort studies. Participant's mean age was 64 ± 5 years and 61% were male. Target lesions (TLs) ranged from under 2 mm to 5.9 mm and 51 were reported as de novo stenosis. Device failure described as wasting of the DeB was reported in two studies (55% and 92.8%). At 6 months TL PP was reported between 70% to 97% for DeBs in the RCTs and cohort studies, and 0% to 26% for non-DeBs. TLs treated with DeBs were associated with a higher primary patency at 6 months as compared to non-DeB balloons (RCTs: odds ratio [OR] 0.25, 95% CI 0.08 to 0.77 and I2 = 19%, cohort studies: OR 0.10, 95% CI 0.03 to 0.31 and an I2 = 20%). No procedure-related major or minor complications were reported.

Conclusions

Current literature reports DeBs as being safe and may convey some benefit in terms of improved rate of restenosis when used to treat AV access disease. However, this body of evidence is small and clinically heterogeneous. A large multicentre RCT may help to clarify the role of DeBs in the percutaneous treatment of AV HD access stenosis.

Early changes in body weight and blood pressure are associated with mortality in incident dialysis patients

BACKGROUND

While much research is devoted to identifying novel biomarkers, addressing the prognostic value of routinely measured clinical parameters is of great interest. We studied early blood pressure (BP) and body weight (BW) trajectories in incident haemodialysis patients and their association with all-cause mortality.

METHODS

In a cohort of 357 incident patients, we obtained all records of BP and BW during the first 90 days on dialysis (over 12 800 observations) and analysed trajectories using penalized B-splines and mixed linear regression models. Baseline comorbidities and all-cause mortality (median follow-up: 2.2 years) were obtained from the French Renal Epidemiology and Information Network (REIN) registry, and the association with mortality was assessed by Cox models adjusting for baseline comorbidities.

RESULTS

During the initial 90 days on dialysis, there were non-linear decreases in BP and BW, with milder slopes after 15 days [systolic BP (SBP)] or 30 days [diastolic BP (DBP) and BW]. SBP or DBP levels at dialysis initiation and changes in BW occurring in the first month or during the following 2 months were significantly associated with survival. In multivariate models adjusting for baseline comorbidities and prescriptions, higher SBP value and BW slopes were independently associated with a lower risk of mortality. Hazard ratios of mortality and 95% confidence intervals were 0.92 (0.85-0.99) for a 10 mmHg higher SBP and 0.76 (0.66-0.88) for a 1 kg/month higher BW change on Days 30-90.

CONCLUSIONS

BW loss in the first weeks on dialysis is a strong and independent predictor of mortality. Low BP is also associated with mortality and is probably the consequence of underlying cardiovascular diseases. These early markers appear to be valuable prognostic factors.

Dialysis Access Anatomy and Interventions: A Primer

The creation of arteriovenous fistulae and the use of arteriovenous grafts are a vital component in the treatment of patients undergoing dialysis. For many patients in this population, these accesses represent the permanent solution to their dialysis needs. Understanding the basic anatomy of the most common accesses used, as well as initial treatment of many underlying causes of access failure is vital for any interventionalist performing such procedures. This article outlines the most common approaches to surgically placed accesses used for renal replacement therapy, as well as the basics of interventional approaches used to treat the most common abnormalities causing their dysfunction.

Pre-existing and Postoperative Intimal Hyperplasia and Arteriovenous Fistula Outcomes

BACKGROUND

The contribution of intimal hyperplasia (IH) to arteriovenous fistula (AVF) failure is uncertain. This observational study assessed the relationship between pre-existing, postoperative, and change in IH over time and AVF outcomes.

STUDY DESIGN

Prospective cohort study with longitudinal assessment of IH at the time of AVF creation (pre-existing) and transposition (postoperative). Patients were followed up for up to 3.3 years.

SETTING & PARTICIPANTS

96 patients from a single center who underwent AVF surgery initially planned as a 2-stage procedure. Veins and AVF samples were collected from 66 and 86 patients, respectively. Matched-pair tissues were available from 56 of these patients.

PREDICTORS

Pre-existing, postoperative, and change in IH over time.

OUTCOMES

Anatomic maturation failure was defined as an AVF that never reached a diameter > 6mm. Primary unassisted patency was defined as the time elapsed from the second-stage surgery to the first intervention.

MEASUREMENTS

Maximal intimal thickness in veins and AVFs and change in intimal thickness over time.

RESULTS

Pre-existing IH (>0.05mm) was present in 98% of patients. In this group, the median intimal thickness increased 4.40-fold (IQR, 2.17- to 4.94-fold) between AVF creation and transposition. However, this change was not associated with pre-existing thickness (r(2)=0.002; P=0.7). Ten of 96 (10%) AVFs never achieved maturation, whereas 70% of vascular accesses remained patent at the end of the observational period. Postoperative IH was not associated with anatomic maturation failure using univariate logistic regression. Pre-existing, postoperative, and change in IH over time had no effects on primary unassisted patency.

LIMITATIONS

The small number of patients from whom longitudinal tissue samples were available and low incidence of anatomic maturation failure, which decreased the statistical power to find associations between end points and IH.

CONCLUSIONS

Pre-existing, postoperative, and change in IH over time were not associated with 2-stage AVF outcomes.

Urgent peritoneal dialysis or hemodialysis catheter dialysis

Worldwide, there is a steady incident rate of patients with end-stage kidney disease (ESKD) who require renal replacement therapy. Of these patients, approximately one-third have an "unplanned" or "urgent" start to dialysis. This can be a very challenging situation where patients have either not had adequate time for education and decision making regarding dialysis modality and appropriate dialysis access, or a decision was made and plans were altered due to unforeseen circumstances. Despite such unplanned starts, clinicians must still consider the patient's ESKD "life-plan", which includes the best initial dialysis modality and access to suit the patient's individual goals and their medical, social, logistic, and facility circumstances. This paper will discuss the considerations of peritoneal dialysis and a peritoneal dialysis catheter access and hemodialysis and central venous catheter access in patients who require an urgent start to dialysis.

Investigating clinical predictors of arteriovenous fistula functional patency in a European cohort

BACKGROUND

Arteriovenous fistula (AVF) failure to mature (FTM) rates contribute to excessive dependence on central venous catheters for haemodialysis. Choosing the most appropriate vascular access site for an individual patient is guided largely by their age, co-morbidities and clinical examination. We investigated the clinical predictors of AVF FTM in a European cohort of patients and applied an existing clinical risk prediction model for AVF FTM to this population.

METHODS

A prospective cohort study was designed that included all patients undergoing AVF creation between January 2009 and December 2014 in a single centre (Belfast City Hospital) who had a functional AVF outcome observed by March 2015.

RESULTS

A total of 525 patients had a functional AVF outcome recorded and were included in the FTM analysis. In this cohort, 309 (59%) patients achieved functional AVF patency and 216 (41%) patients had FTM. Female gender [P < 0.001, odds ratio (OR) 2.03 (CI 1.37-3.02)] and lower-arm AVF [P < 0.001, OR 4.07 (CI 2.77-5.92)] were associated with AVF FTM. The Lok model did not predict FTM outcomes based on the associated risk stratification in our population.

CONCLUSIONS

In this European study, female gender was associated with twice the risk of AVF FTM and a lower-arm AVF with four times the risk of FTM. The FTM risk prediction model was not found to be discriminative in this population. Clinical risk factors for AVF FTM vary between populations; we would recommend that units investigate their own clinical predictors of FTM to maximize AVF functional patency and ultimately survival in dialysis patients. Clinical predictors of AVF FTM may not be sufficient on their own to improve vascular access functional patency rates.

Differences in Initial Hemodialysis Vascular Access Use Among Glomerulonephritis Subtypes in the United States

BACKGROUND

The type of vascular access used for hemodialysis affects patient morbidity and mortality. Whether vascular access types differ by glomerulonephritis (GN) subtype in the US hemodialysis population has not been investigated.

STUDY DESIGN

Cross-sectional observational study.

SETTING & PARTICIPANTS

We identified all adult (aged ≥ 18 years) patients within the US Renal Data System who initiated hemodialysis therapy from July 2005 through December 2011 with a diagnosis of end-stage renal disease attributed to any of 4 primary (focal segmental glomerulosclerosis, immunoglobulin A nephropathy [reference group], membranous nephropathy, and membranoproliferative GN) or 2 secondary (lupus nephritis and vasculitis) GN subtypes.

PREDICTOR

GN subtype.

OUTCOMES

ORs with 95% CIs for arteriovenous fistula versus central venous catheter (CVC) use and for arteriovenous graft versus CVC use were computed using multinomial logistic regression, with adjustment for demographic, socioeconomic, comorbidity, and duration of nephrology care covariates.

RESULTS

Among 29,015 patients, CVC use at initiation of hemodialysis therapy was substantially higher in patients with lupus nephritis (89.2%) or vasculitis (91.2%) compared with patients with primary GN subtypes (72.7%-79.8%). After adjustment and compared with patients with immunoglobulin A nephropathy, patients with lupus nephritis or vasculitis were as likely to have used an arteriovenous graft (ORs of 0.94 [95% CI, 0.70-1.27] and 0.80 [95% CI, 0.56-1.13], respectively) but significantly less likely to have used an arteriovenous fistula (ORs of 0.66 [95% CI, 0.57-0.76] and 0.54 [95% CI, 0.45-0.63], respectively), whereas patients with any comparator primary GN subtype were at least as likely to have used either of these 2 access types.

LIMITATIONS

Potential misclassification of exposure; residual confounding by unmeasured covariates; inability to determine causes of observed associations; lacking longitudinal data for vascular access use.

CONCLUSIONS

Significant differences in vascular access distributions at initiation of hemodialysis therapy are apparent among GN subtypes. The unacceptably high use of CVCs in patients with lupus nephritis and vasculitis is particularly concerning. Further studies are needed to identify any potentially modifiable factors underlying these findings.

Going Upstream: Coordination to Improve CKD Care

Care coordination for patients with chronic kidney disease has been shown to be effective in improving outcomes and reducing costs. However, few patients with CKD benefit from this systematic management of their kidney disease and other medical conditions. As a result, outcomes for patients with kidney disease are not optimal, and their cost of care is increased. For those patients who transition to kidney failure treatment in the United States, the transition does not go as well as it could. The effectiveness of treatments to delay progression of kidney disease in contemporary clinical practice does not match the efficacy of these treatments in clinical trials. Conservative care for kidney disease, which should be an option for patients who are very old and very sick, is not considered often enough or seriously enough. Opportunities for early and even pre-emptive transplantation are missed, as are opportunities for home dialysis. The process of dialysis access creation is rarely optimal. The consequence is care which is not as good as it could be, and much more expensive than it should be. We describe our initial efforts to implement care coordination for chronic kidney disease in routine clinical care and attempt to project some of the benefits to patients and the cost savings.

Surveillance for Hemodialysis Access Stenosis: Usefulness of Ultrasound Vector Volume Flow

Purpose

To investigate if ultrasound vector-flow imaging (VFI) is equal to the reference method ultrasound dilution technique (UDT) in estimating volume flow and changes over time in arteriovenous fistulas (AVFs) for hemodialysis.

Materials and methods

From January 2014 to January 2015, patients with end-stage renal disease and matured functional AVFs were consecutively solicited to participate in this prospective study. All patients were included after written informed consent and approval by the National Committee on Biomedical Research Ethics and the local Ethics Committee (journal no. H-4-2014-FSP). VFI and UDT measurements were performed monthly over a six-month period. Nineteen patients were included in the study. VFI measurements were performed before dialysis, and UDT measurements after. Statistical analyses were performed with Bland-Altman plot, Student's t-test, four-quadrant plot, and regression analysis. Repeated measurements and precision analysis were used for reproducibility determination.

Results

Precision measurements for UDT and VFI were 32% and 20%, respectively (p = 0.33). Average volume flow measured with UDT and VFI were 1161 mL/min (±778 mL/min) and 1213 mL/min (±980 mL/(min), respectively (p = 0.3). The mean difference was -51 mL/min (CI: -150 mL/min to 46 mL/min) with limits of agreement from -35% to 54%, with a strong correlation (r2 = 0.87). A large change in volume flow between dialysis sessions detected by UDT was confirmed by VFI (p = 0.0001), but the concordance rate was poor (0.72).

Conclusions

VFI is an acceptable method for volume flow estimation and volume flow changes over time in AVFs.

Pre-emptive correction for haemodialysis arteriovenous access stenosis

BACKGROUND

Guidelines recommend routine arteriovenous (AV) graft and fistula surveillance (technology-based screening) in addition to clinical monitoring (physical examination) for early identification and pre-emptive correction of a stenosis before the access becomes dysfunctional. However, consequences on patient-relevant outcomes of pre-emptive correction of a stenosis in a functioning access as opposed to deferred correction, i.e. correction postponed to when the access becomes dysfunctional, are uncertain.

OBJECTIVES

We aimed to evaluate 1) whether pre-emptive correction of an AV access stenosis improves clinically relevant outcomes; 2) whether the effects of pre-emptive correction of an AV access stenosis differ by access type (fistula versus graft), aim (primary and secondary prophylaxis), and surveillance method for primary prophylaxis (Doppler ultrasound for the screening of functional and anatomical changes versus measurement of the flow in the access); and 3) whether other factors (dialysis duration, access location, configuration or materials, algorithm for referral for intervention, intervention strategies (surgical versus radiological or other), or study design) explain the heterogeneity that might exist in the effect estimates.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 30 November 2015 using search terms relevant to this review.

SELECTION CRITERIA

We included all studies of any access surveillance method for early identification and pre-emptive treatment of an AV access stenosis.

DATA COLLECTION AND ANALYSIS

We extracted data on potentially remediable and irremediable failure of the access (i.e. thrombosis and access loss respectively); infection and mortality; and resource use (hospitalisation, diagnostic and intervention procedures). Analysis was by a random effects model and results expressed as risk ratio (RR), hazard ratio (HR) or incidence rate ratio (IRR) with 95% confidence intervals (CI).

MAIN RESULTS

We identified 14 studies (1390 participants), nine enrolled adults without a known access stenosis (primary prophylaxis; three studies including people using fistulas) and five enrolled adults with a documented stenosis in a non-dysfunctional access (secondary prophylaxis; three studies in people using fistulas). Study follow-up ranged from 6 to 38 months, and study size ranged from 58 to 189 participants. In low- to moderate-quality evidence (based on GRADE criteria) in adults treated with haemodialysis, relative to no surveillance and deferred correction, surveillance with pre-emptive correction of an AV stenosis reduced the risk of thrombosis (RR 0.79, 95% CI 0.65 to 0.97; I² = 30%; 18 study comparisons, 1212 participants), but had imprecise effect on the risk of access loss (RR 0.81, 95% CI 0.65 to 1.02; I² = 0%; 11 study comparisons, 972 participants). In analyses subgrouped by access type, pre-emptive stenosis correction did not reduce the risk of thrombosis (RR 0.95, 95% CI 0.8 to 1.12; I² = 0%; 11 study comparisons, 697 participants) or access loss in grafts (RR 0.9, 95% CI 0.71 to 1.15; I² = 0%; 7 study comparisons; 662 participants), but did reduce the risk of thrombosis (RR 0.5, 95% CI 0.35 to 0.71; I² = 0%; 7 study comparisons, 515 participants) and the risk of access loss in fistulas (RR 0.5, 95% CI 0.29 to 0.86; I² = 0%; 4 studies; 310 participants). Three of the four studies reporting access loss data in fistulas (199 participants) were conducted in the same centre. Insufficient data were available to assess whether benefits vary by prophylaxis aim in fistulas (i.e. primary and secondary prophylaxis). Although the magnitude of the effects of pre-emptive stenosis correction was considerable for patient-centred outcomes, results were either heterogeneous or imprecise. While pre-emptive stenosis correction may reduce the rates of hospitalisation (IRR 0.54, 95% CI 0.31 to 0.93; I² = 67%; 4 study comparisons, 219 participants) and use of catheters (IRR 0.58, 95% CI 0.35 to 0.98; I² = 53%; 6 study comparisons, 394 participants), it may also increase the rates of diagnostic procedures (IRR 1.78, 95% CI 1.18 to 2.67; I² = 62%; 7 study comparisons, 539 participants), infection (IRR 1.74, 95% CI 0.78 to 3.91; I² = 0%; 3 studies, 248 participants) and mortality (RR 1.38, 95% CI 0.91 to 2.11; I² = 0%; 5 studies, 386 participants).In general, risk of bias was high or unclear in most studies for many domains we assessed. Four studies were published after 2005 and only one had evidence of registration within a trial registry. No study reported information on authorship and/or involvement of the study sponsor in data collection, analysis, and interpretation.

AUTHORS' CONCLUSIONS

Pre-emptive correction of a newly identified or known stenosis in a functional AV access does not improve access longevity. Although pre-emptive stenosis correction may be promising in fistulas existing evidence is insufficient to guide clinical practice and health policy. While pre-emptive stenosis correction may reduce the risk of hospitalisation, this benefit is uncertain whereas there may be a substantial increase (i.e. 80%) in the use of access-related procedures and procedure-related adverse events (e.g. infection, mortality). The net effects of pre-emptive correction on harms and resource use are thus unclear.

Hemodialysis arteriovenous fistula as first option not necessary in elderly patients

OBJECTIVE

Kidney Disease Outcomes Quality Initiative guidelines recommend arteriovenous fistulas as the preferred access for hemodialysis patients. However, this may not hold across all populations of patients, especially the elderly, given their comorbidities and relatively reduced life expectancy. Therefore, we investigated whether fistulas held benefit over arteriovenous grafts as hemodialysis access in elderly patients.

METHODS

We retrospectively searched a vascular access database to compare the outcomes for 138 fistulas and 44 grafts that were placed in elderly patients (≥75 years old) during a 4-year period at a tertiary medical center.

RESULTS

The primary failure rate was higher for the fistulas compared with the grafts (odds ratio, 2.89; P = .008), and more fistulas required one or more interventions before their successful use compared with grafts (31% vs 10%, respectively; P = .03). In addition, the time to catheter-free dialysis was longer for fistulas than for grafts (P < .001). However, the primary and secondary patency rates were comparable between the fistulas and grafts and between the different access locations. The all-cause mortality rates were also comparable between the fistula and graft groups.

CONCLUSIONS

Despite the Fistula First Initiative recommendations, grafts need not be discounted as a first-line hemodialysis access option in select elderly patients.

Association of Vascular Access Type with Mortality, Hospitalization, and Transfer to In-Center Hemodialysis in Patients Undergoing Home Hemodialysis

BACKGROUND AND OBJECTIVES

In individuals undergoing in-center hemodialysis (HD), use of central venous catheters (CVCs) is associated with worse clinical outcomes compared with use of arteriovenous access. However, it is unclear whether a similar difference in risk by vascular access type is present in patients undergoing home HD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our study examined the associations of vascular access type with all-cause mortality, hospitalization, and transfer to in-center HD in patients who initiated home HD from 2007 to 2011 in 464 facilities in 43 states in the United States. Patients were followed through December 31, 2011. Data were analyzed using competing risks hazards regression, with vascular access type at the start of home HD as the primary exposure in a propensity score-matched cohort (1052 patients; 526 with CVC and 526 with arteriovenous access).

RESULTS

Over a median follow-up of 312 days, 110 patients died, 604 had at least one hospitalization, and 202 transferred to in-center hemodialysis. Compared with arteriovenous access use, CVC use was associated with higher risk for mortality (hazard ratio, 1.73; 95% confidence interval, 1.18 to 2.54) and hospitalization (hazard ratio, 1.19; 95% confidence interval, 1.02 to 1.39). CVC use was not associated with increased risk for transfer to in-center HD. The results of analyses in the entire unmatched cohort (2481 patients), with vascular access type modeled as a baseline exposure at start of home HD or a time-varying exposure, were similar. Analyses among a propensity score-matched cohort of patients undergoing in-center HD also showed similar risks for death and hospitalization with use of CVCs.

CONCLUSIONS

In a large cohort of patients on home HD, CVC use was associated with higher risk for mortality and hospitalization. Additional studies are needed to identify interventions which may reduce risk associated with use of CVCs among patients undergoing home HD.

Reduction in Staphylococcus aureus bacteraemia rates in patients receiving haemodialysis following alteration of skin antisepsis procedures

This study examined all cases of Staphylococcus aureus bacteraemia (SAB) in the haemodialysis cohort at the Royal Darwin Hospital, Australia over a seven-year period. Midway through this period, antisepsis for arteriovenous fistulae (AVF) and central venous catheters (CVC) changed from 0.5% chlorhexidine solution to 2% chlorhexidine solution. Rates of SAB episodes were calculated using registry data. Trends in SAB over time were analysed using an interrupted regression analysis. Following the change to 2% chlorhexidine, average SAB rates decreased by 68%, and it is estimated that 0.111 cases of SAB/patient-year were prevented. CVC-related SAB rates remained low throughout. These results support the use of 2% chlorhexidine in skin antisepsis for patients with AVF.

Patterns of Dialysis Initiation Affect Outcomes of Incident Hemodialysis Patients

AIMS

There is a trend toward deferring the initiation of chronic dialysis until absolutely indicated. This strategy, however, might lead to increased uncertainties in the timing of dialysis access creation prior to dialysis onset for patients approaching end-stage renal disease (ESRD), and the impact of which on hard end points remains largely unclear. We hereby investigated the effect of varied patterns of dialysis initiation on outcomes of new-onset hemodialysis (HD) patients.

METHODS

Four hundred sixty-two prospectively recruited patients were stratified into planned elective (n = 117, 25%), planned urgent (n = 65, 14%) or unplanned urgent (n = 280, 61%) starters based on the timing of access creation with respect to dialysis initiation. The outcome measures were all-cause mortality, hospitalization and access reconstruction over 2 years.

RESULTS

The mean estimated glomerular filtration rate (eGFR) was higher in the planned elective than in the planned urgent or unplanned urgent starters at access creation (5.3 vs. 4.4 or 4.3 ml/min/1.73 m2), but not at dialysis initiation (4.2 vs. 3.9 or 4.3 ml/min/1.73 m2). During the follow-up, the planned elective population exhibited the lowest rates of overall mortality and hospitalization, but not access reconstruction. Multivariate Cox's regression analysis showed that the planned urgent and the unplanned urgent groups, comparing to the planned elective population, displayed a greater risk of early death (hazards ratio [HR] 3.324, 95% CI 1.409-7.840; HR 2.510, 95% CI 1.177-5.355, respectively) and early hospitalization (sub-hazards ratio [SubHR] 2.238, 95% CI 1.530-3.274; SubHR 1.529, 95% CI 1.096-2.133, respectively).

CONCLUSION

Incident ESRD patients undergoing planned elective start of HD, compared to their planned or unplanned urgent counterparts, showed reduced risk of overall mortality and hospitalization in the first 2 years after commencing long-term dialysis at a mean eGFR <5 ml/min/1.73 m2.

Epidemiology of haemodialysis catheter complications: a survey of 865 dialysis patients from 14 haemodialysis centres in Henan province in China

OBJECTIVES

To investigate the incidence rates and risk factors for catheter-related complications in different districts and populations in Henan Province in China.

DESIGN

Cross-sectional.

SETTING

Fourteen hospitals in Henan Province.

PARTICIPANTS

865 patients with renal dysfunction undergoing dialysis using catheters between October 2013 and October 2014.

MAIN OUTCOME MEASURES

The main outcome measures were complications, risk factors and patient characteristics. Catheter-related complications included catheter-related infection (catheter exit-site infection, catheter tunnel infection and catheter-related bloodstream infection), catheter dysfunction (thrombosis, catheter malposition or kinking, and fibrin shell formation) and central vein stenosis.

RESULTS

The overall incidence rate was 7.74/1000 catheter-days, affecting 38.61% of all patients, for catheter infections, 10.58/1000 catheter-days, affecting 56.65% of all patients, for catheter dysfunction, and 0.68/1000 catheter-days, affecting 8.79% of all patients, for central vein stenosis. Multivariate analysis showed that increased age, diabetes, primary educational level or below, rural residence, lack of a nephropathy visit before dialysis and pre-established permanent vascular access, not taking oral drugs to prevent catheter thrombus, lower serum albumin levels and higher ferritin levels were independently associated with catheter infections. Rural residence, not taking oral drugs to prevent thrombus, lack of an imaging examination after catheter insertion, non-tunnel catheter type, lack of medical insurance, lack of nephropathy visit before dialysis and pre-established permanent vascular access, left-sided catheter position, access via the femoral vein and lower haemoglobin level were independently associated with catheter dysfunction. Diabetes, lack of nephropathy visit before dialysis and pre-established permanent vascular access, lack of oral drugs to prevent catheter thrombus, left-sided catheter location and higher number of catheter insertions, were independently associated with central vein stenosis.

CONCLUSIONS

The rate of catheter-related complications was high in patients with end-stage renal disease in Henan Province. Our finding suggest that strategies should be implemented to decrease complication rates.

Leakage of central venous catheter locking fluid by hemodynamic transport

Central venous catheters are often filled when not in use with an anticoagulating fluid, usually heparinized saline, known as the locking fluid. However, the use of the locking fluid is associated with known risks because of "leakage" of the lock. A new hypothesis is proposed here to explain the lock fluid leakage: that the leakage is due to advective and diffusive mass transfer by blood flow around the catheter tip in situ. On the basis of previous in vitro experiments, the leakage mechanism has been hypothesized to be fluid motion driven by buoyancy forces between the heavier blood and the lighter locking fluid. The current hypothesis is justified by a simple one-dimensional mass transfer model and more sophisticated three-dimensional computational hemodynamic simulations of an idealized catheter. The results predict an initial, fast (<10 seconds) advection-dominated phase, which may deplete up to 10% of the initial lock, followed by a slow diffusion-limited phase which predicts an additional 1-2% of leakage during a 48 hour period. The current results predict leakage rates that are more consistent with published in vivo data when compared with the buoyancy hypothesis predictions, which tend to grossly overestimate leakage rates.

Systemic Effects of Hemodialysis Access

Patients with advanced chronic kidney disease are at a high risk of cardiovascular events. Patients with end-stage renal disease have a particularly high morbidity and mortality, in part attributed to the complications and dysfunction related to vascular access in this population. Creation of an arteriovenous access for HD is considered standard of care for most patients and has distinct advantages including less likelihood of infections, less need for intervention, and positive impact on survival as compared with usage of a catheter. However, creation of an arteriovenous shunt incites a series of events that significantly impacts cardiovascular and neurohormonal health in both positive and negative ways. This article will review the short- and long-term effects of dialysis access on cardiovascular, neurohormonal, and pulmonary systems as well as a brief review of their effect on survival on HD. Presence of other comorbidities in a patient with dialysis access can amplify these effects, and these considerations are of paramount importance in individualizing the approach to not only the choice of vascular access but also the modality of kidney replacement therapy.

Convective Leakage Makes Heparin Locking of Central Venous Catheters Ineffective Within Seconds: Experimental Measurements in a Model Superior Vena Cava

Central venous catheters (CVCs), placed in the superior vena cava (SVC) for hemodialysis or chemotherapy, are routinely filled while not in use with heparin, an anticoagulant, to maintain patency and prevent thrombus formation at the catheter tip. The heparin-locking procedure, however, places the patient at risk for systemic bleeding, as heparin is known to leak from the catheter into the blood stream. We provide evidence from detailed in vitro experiments that shows the driving mechanism behind heparin leakage to be convective-diffusive transport due to the pulsatile flow surrounding the catheter. This novel mechanism is supported by experimental planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV) measurements of flow velocity and heparin transport from a CVC placed inside a model SVC inside a pulsatile flow loop. The results predict an initial, fast (<10 s), convection-dominated phase that rapidly depletes the concentration of heparin in the near-tip region, the region of the catheter with side holes. This is followed by a slow, diffusion-limited phase inside the catheter lumen, where the concentration is still high, that is insufficient at replenishing the lost heparin concentration in the near-tip region. The results presented here, which are consistent with previous in vivo estimates of 24 hour leakage rates, predict that the concentration of heparin in the near-tip region is essentially zero for the majority of the interdialytic phase, rendering the heparin locking procedure ineffective.

The Reasons for the Failure of the Primary Arteriovenous Fistula Surgery in Patients with End-Stage Renal Disease

Purpose

To analyze the reasons for the failure of the primary arteriovenous fistula surgery and explore preventive measures.

Methods

A total of 819 patients with end-stage renal disease were enrolled in the study. Autologous arteriovenous fistula surgery was performed on all patients. Their clinical data of hemoglobin (HB), albumin (ALB), cholesterol (CHOL), parathyroid hormone (PTH), blood glucose and blood pressure were collected before surgery, while the diameters of the radial artery and cephalic vein were measured by ultrasound.

Results

The operations in 742 patients were successful, but failed in 77 cases (accounting for 7.07%). The failure group was significantly older (61.3 ± 13.4 years) than the successful group (45.6 ± 11.2 years). The ratio of diabetes 36 (46.8%) and hypertension 20 (26.0%) was significantly higher in the failure group than in the successful group, respectively 235 (31.7%) and 145 (19.5%). The patients with blood pressure below 120/70 mm Hg had a higher risk of failed surgery (36.4%) than those with blood pressure above 120/70 mm Hg (9.16%). The cephalic vein and radial artery diameters were significantly smaller in the failure group (1.35 ± 0.64 mm, 2.13 ± 0.81 mm) than in the successful group (1.98 ± 0.47 mm, 2.47 ± 0.74 mm); the PTH levels in the failure group were significantly higher (782.39 ± 423.85) than in the successful group (378.83 ± 352.21).

Conclusions

The autogenous arteriovenous fistula surgery failure highly correlated with the patient's age, blood pressure, the primary disease and the vessel diameter. In addition, the PTH levels had a certain correlation with the failure of the fistula surgery.

Patients started on hemodialysis with tunneled dialysis catheter have similar survival after arteriovenous fistula and arteriovenous graft creation

OBJECTIVE

Current guidelines suggest that arteriovenous fistula (AVF) is associated with survival advantage over arteriovenous graft (AVG). However, AVFs often require months to become functional, increasing tunneled dialysis catheter (TDC) use, which can erode the benefit of an AVF. We sought to compare survival in patients with end-stage renal disease after creation of an AVF or AVG in patients starting hemodialysis (HD) with a TDC and to identify patient populations that may benefit from preferential use of AVG over AVF.

METHODS

Using U.S. Renal Data System databases, we identified incident HD patients in 2005 through 2008 and observed them through 2008. Initial access type and clinical variables including albumin levels were assessed using U.S. Renal Data System data collection forms. Attempts at AVF and AVG creation in patients who started HD through a TDC were identified by Current Procedural Terminology codes. We accounted for the effect of changes in access type by truncating follow-up when an additional AVF or AVG was performed. Survival curves were then constructed, and log-rank tests were used for pairwise survival comparisons, stratified by age. Multivariate analysis was performed with Cox proportional hazards regressions; variables were chosen using stepwise elimination. An interaction of access type and albumin level was detected, and Cox models using differing thresholds for albumin level were constructed. The primary outcome was survival.

RESULTS

Among the 138,245 patients who started with a TDC and had complete records amenable for analysis, 22.8% underwent AVF creation (mean age ± standard deviation, 68.9 ± 12.5 years; 27.8% mortality at 1 year) and 7.6% underwent AVG placement (70.2 ± 12.0 years; 28.2% mortality) within 3 months of HD initiation; 69.6% remained with a TDC (63.2 ± 15.4 years; 33.8% mortality). In adjusted Cox proportional hazards regression, AVF creation is equivalent to AVG placement in terms of survival (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.93-1.02; P = .349). AVG placement is superior to continued TDC use (HR, 1.54; 95% CI, 1.48-1.61; P < .001). In patients older than 80 years with albumin levels >4.0 g/dL, AVF creation is associated with higher mortality hazard compared with AVG creation (HR, 1.22; 95% CI, 1.04-1.43; P = .013).

CONCLUSIONS

For patients who start HD through a TDC, placement of an AVF and AVG is associated with similar mortality hazard. Further study is necessary to determine the ideal access for patients in whom the survival advantage of an AVF over an AVG is uncertain.

An Outcomes Comparison of Native Arteriovenous Fistulae, Polytetrafluorethylene Grafts, and Cryopreserved Vein Allografts

BACKGROUND

Despite almost 2 decades of experience with cadaveric vein, there remains a paucity of available data regarding the role of cadaveric vein in hemodialysis, specifically with regard to outcomes and patency. Observations from our own experience have suggested that cadaveric vein grafts (CVGs) provide good outcomes, particularly in patients with recurrent access failure. Accordingly, this study aims to comparatively examine patency, access-related outcomes, and survival in patients undergoing placement of arteriovenous fistulae (AVF), polytetrafluorethylene (PTFE) grafts, and CVGs.

METHODS

This is a single institution 11-year retrospective case series evaluating the outcomes of 210 patients who underwent creation of AVF, PTFE grafts, and CVGs for hemodialysis access. Patients in the AVF (n = 70) and arteriovenous graft (AVG; n = 70) groups were matched to the CVG (n = 70) group by age, gender, and access location. Postoperative end points for all groups included primary and assisted patency, cause of access abandonment, and survival.

RESULTS

Patients were matched for age (P = 0.8707), gender (P = 0.6958), and access location and no significant differences existed between groups. AVF showed superior primary patency at 30 days, 1 year (64.3%, P < 0.0001) and 2 years (54.3%, P = 0.0091) in comparison to both AVG and CVG. AVG had reduced patency at 30 days (84.3%, P = 0.0009), 1 year (50.0%, P < 0.0001), and 2 years (32.9%, P = 0.0001) in comparison to AVF and CVG groups. Overall, AVF had the highest patency at all-time points followed, respectively by CVG and AVG. No significant difference existed between AVF and CVG groups with regard to secondary patency at 30 days (98.6% vs. 97.1%, P = 1.0000), 1 year (81.4% vs. 78.6%, P = 0.6749), and 2 years (68.6% vs. 51.4%, P = 0.0573). AVG patients had decreased survival (years) after access creation in comparison to AVF and CVG groups (P = 0.0003).

CONCLUSIONS

Our findings lend further support to the use of cadaveric vein for hemodialysis access surgery. As demonstrated through this comparative study, CVGs are capable of providing favorable results with regard to patency, access longevity, and patient survival. These current outcomes indicate that cadaveric vein is a sustainable alternative to PTFE for hemodialysis access surgery and should be accordingly considered for difficult access patients.

Effect of a Rapid Clinical Protocol to the Conversion from Central Venous Hemodialysis Catheter to Arteriovenous Access

Purpose

Evaluation of the rapid conversion protocol that includes an ambulatory dialysis access center (DAC), and a three-step clinical pathway, to the conversion rate from central venous hemodialysis (HD) catheter to functioning arteriovenous (AV) access.

Methods

Prospective data were collected on 97 consecutive catheter-dependent HD patients. DAC is defined as an ambulatory unit, able to accommodate clinic visits, ultrasound examinations, surgical, interventional and hybrid procedures. Step I: initial evaluation, vein mapping and creation of AV access. Step II: clinical evaluation in two weeks and if failure identified, secondary procedure to restore function. Step III: evaluation in four weeks after creation, and additional procedure to promote maturation if indicated. The success rate, time to conversion and time to catheter removal were recorded.

Results

From the 97 consecutive referred patients, eight patients were excluded. From the remaining 89 patients, 99% were successfully converted to AV access. Seventy-three percent of the patients were converted to native arteriovenous fistulae and 27% of the patients to prosthetic arteriovenous shunts. The median time from creation to HD catheter removal was 63 (SD 41) days. Fifty-two percent of the patients required at least one additional secondary procedure to accomplish successful conversion

Conclusions

High rates of timely conversion from catheter to AV access, primarily AV fistulae, can be accomplished within the context of the rapid conversion protocol.

Starting Hemodialysis with Catheter and Mortality Risk: Persistent Association in a Competing Risk Analysis

Purpose

The vascular access (VA) used at hemodialysis (HD) inception is involved in the mortality risk. We analyzed the survival of incident patients over time according to the initial VA and the VA profile of patients who died during the first year of follow-up.

Methods

Data of VA were obtained from 9956 incident HD patients from the Catalan Registry.

Results

Over 12 years, 47.9% of patients initiated HD with a fístula, 1.2% with a graft, 15.9% with a tunneled catheter and 35% with an untunneled catheter. Regarding fistula use, the hazard ratio of death for all-causes over time when applying a multivariate competing risk model was 1.55 [95% confidence interval (CI): 1.42-1.69] and 1.43 (95% CI: 1.33-1.54) for patients with tunneled and untunneled catheter, respectively. During the first year of follow-up, the crude all-cause mortality rate (deaths/100 patient-years) was higher during the early (first 120 days) compared to the late (121-365 days) period: 18.3 (95% CI: 16.8-19.8) versus 15.4 (95% CI: 14.5-16.5). Regarding fistula use, for patients using untunneled and tunneled catheter, the odds ratio of death in the early period for all-causes was 3.66 (95% CI: 2.80-4.81) and 2.97 (95% CI: 2.17-4.06), for cardiovascular causes it was 2.76 (95% CI: 1.90-4.01) and 1.84 (95% CI: 1.17-2.89) and for infection-related causes it was 6.62 (95% CI: 3.11-14.05) and 4.58 (95% CI: 2.00-10.52), respectively.

Conclusions

Half of all incident patients in Catalonia are exposed to excessive mortality risk related to catheter and this scenario can be improved by early fistula placement.

New Technology: Heparin and Antimicrobial-Coated Catheters

Although tunneled hemodialysis catheter must be considered the last option for vascular access, it is necessary in some circumstances in the dialysis patient. Thrombosis and infections are the main causes of catheter-related comorbidity. Fibrin sheath, intimately related with the biofilm, is the precipitating factor of this environment, determining catheter patency and patient morbidity. Its association with bacterial overgrowth and thrombosis has led to the search of multiple preventive measures. Among them is the development of catheter coatings to prevent thrombosis and infections. There are two kinds of treatments to cover the catheter surface: antithrombotic and antimicrobial coatings. In nondialysis-related settings, mainly in intensive care units, both have been shown to be efficient in the prevention of catheter-related infection. This includes heparin, silver, chlorhexidine, rifampicine and minocycline. In hemodialysis population, however, few studies on surface-treated catheters have been made and they do not provide evidence that shows complication reduction. The higher effectiveness of coatings in nontunneled catheters may depend on the short average life of these devices. Hemodialysis catheters need to be used over long periods of time and require clinical trials to show effectiveness of coatings over long periods. This also means greater knowledge of biofilm etiopathogeny and fibrin sheath development.

Abdominal Wall Grafts: A Viable Addition to Arteriovenous Access Strategies

BACKGROUND

We seek to present our experience with innovative abdominal wall arteriovenous access grafts for patients who have run out of traditional dialysis access options.

METHODS

We retrospectively reviewed our cohort of patients who have undergone creation of abdominal wall grafts. In all patients, an iliac artery was used for inflow and either an iliac vein or the distal inferior vena cava (IVC) was use for the outflow. Ringed polytetrafluorethylene (PTFE), nonringed PTFE, and bovine carotid artery were used as access conduits.

RESULTS

Our 12-patient cohort had a mean primary patency of 17.4 months with mean secondary patency of 33 months. There were no operative deaths noted and 4 total graft infections.

CONCLUSIONS

Abdominal wall grafts with iliac vessel inflow and/or outflow represent viable alternatives for patients who have exhausted more traditional dialysis access options.

Setting Priorities for Optimizing Vascular Access Decision Making--An International Survey of Patients and Clinicians

BACKGROUND

Many decisions around vascular access for haemodialysis warrant a collaborative treatment decision-making process, involving both clinician and patient. Yet, patients' experiences in this regard have been suboptimal. Although clinical practice guidelines could facilitate collaborative decision making, they often focus on the clinicians' side of the process, while failing to address the patients' perspective. The objective of this study was to explore and compare kidney patients' and clinicians' views on what vascular access-related decisions deserved priority for developing guidelines that will contribute to optimizing collaborative decision making.

METHODS

In the context of updating their vascular access guideline, European Renal Best Practice surveyed an international panel of 85 kidney patients, 687 nephrologists, 194 nurses, and 140 surgeons/radiologists. In an electronic questionnaire, respondents rated 42 vascular access-related topics on a 5-point Likert scale. Based on mean standardized ratings, we compared priority ratings between patients and each clinician group.

RESULTS

Selection of access type and site, as well as prevention of access infections received top priority across all respondent groups. Patients generally assigned higher priority to decisions regarding managing adverse effects of arteriovenous access and patient involvement in care, while clinicians more often prioritized decisions around sustaining patients' access options, technical aspects of access creation, and optimizing fistula maturation and patency.

CONCLUSION

Apart from identifying the most pressing knowledge gaps, our study provides pointers for developing guidelines that may improve healthcare professionals' understanding of when to involve patients along the vascular access pathway.

Association Between Vascular Access Dysfunction and Subsequent Major Adverse Cardiovascular Events in Patients on Hemodialysis: A Population-Based Nested Case-Control Study

The association between dialysis vascular access dysfunction and the risk of developing major adverse cardiovascular events (MACE) in hemodialysis patients is unclear and has not yet been investigated. We analyzed data from the National Health Insurance Research Database of Taiwan to quantify this association. Adopting a case-control design nested within a cohort of patients who received hemodialysis from 2001 to 2010, we identified 9711 incident cases of MACE during the stage of stable maintenance dialysis and 19,422 randomly selected controls matched to cases on age, gender, and duration of dialysis. Events of vascular access dysfunction in the 6-month period before the date of MACE onset (ie, index date) for cases and before index dates for controls were evaluated retrospectively. The presence of vascular access dysfunction was associated with a 1.385-fold higher odds of developing MACE as estimated from the logistic regression analysis. This represents a significantly increased adjusted odds ratio (OR) at 1.268 (95% confidence interval [CI] = 1.186-1.355) after adjustment for comorbidities and calendar years of initiating dialysis. We also noted a significant exposure-response trend (P < 0.001) between the frequency of vascular access dysfunction and MACE, with the greatest risk (adjusted OR = 1.840, 95% CI = 1.549-2.186) noted in patients with ≥3 vascular access events. We concluded that dialysis vascular access dysfunction was significantly associated with an increased risk of MACE. Hence, vascular access failure can be an early sign for MACE in patients receiving maintenance hemodialysis. Active monitoring and treatment of cardiovascular risk factors and related diseases, not merely managing vascular access dysfunction, would be required to reduce the risk of MACE.

Self-cannulation for haemodialysis: patient attributes, clinical correlates and self-cannulation predilection models

BACKGROUND AND OBJECTIVES

With emerging evidence in support of home haemodialysis (HHD), patient factors which determine uptake of the modality need to be better understood. Self-cannulation (SC) is a major step towards enabling self-care 'in-centre' and at home and remains the foremost barrier to its uptake. Human factors governing this aspect of HD practice are poorly understood. The aim of this study is to better understand self-cannulation preferences and factors which define them in end stage renal disease (ESRD).

DESIGN

In this multicentre study, 508 of 535 patients from predialysis (Group A: n = 222), in-centre (Group B: n = 213), and home HD (Group C: n = 100) responded to a questionnaire with 3 self-cannulation questions. Simultaneously, data on clinical, cognitive and psychosocial variables were ascertained. The primary outcome measure was 'perceived ability to self-cannulate AV access'. Predictive models were developed using logistic regression analysis.

RESULTS

36.6% of predialysis patients (A) and 29.1% of the 'in-centre' haemodialysis patients (B) felt able to consider SC for HD. Technical-skills related apprehension was highest in Group B (14.4%) patients. Response to routine venepuncture and the types of SC concerns were significant predictors of perceived ability to self-cannulate. There was no significant difference in concern for pain across the groups. In multivariable regression analysis, age, education level, 3 MS score, hypoalbuminemia in Groups B & C and additionally, attitude to routine phlebotomy and the nature of specific concern for self-cannulation in Groups A, B and C, are significant predictors of SC preference. The unadjusted c-statistics of models 1 (derived from Group A and validated on A) and 2 (derived from B+C and validated on B), are 0.76(95% CI 0.69, 0.83) and 0.80 (95% CI 0.74, 0.87) respectively.

CONCLUSIONS

There is high prevalence of perceived ability to self-cannulate. Modifiable SC concerns exist in ESRD. The use of predictive models to objectively define and target education and training strategies could potentially impact on HD self-management and future uptake of home HD.

Cause of Death in Patients With Diabetic CKD Enrolled in the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT)

BACKGROUND

The cause of death in patients with chronic kidney disease (CKD) varies with CKD severity, but variation has not been quantified.

STUDY DESIGN

Retrospective analysis of prospective randomized clinical trial.

SETTING & PARTICIPANTS

We analyzed 4,038 individuals with anemia and diabetic CKD from TREAT, a randomized trial comparing darbepoetin alfa and placebo.

PREDICTORS

Baseline estimated glomerular filtration rate (eGFR) and protein-creatinine ratio (PCR).

OUTCOMES

Cause of death as adjudicated by a blinded committee.

RESULTS

Median eGFR and PCR ranged from 20.6 mL/min/1.73 m(2) and 4.1 g/g in quartile 1 (Q1) to 47.0 mL/min/1.73 m(2) and 0.1 g/g in Q4 (P<0.01). Of 806 deaths, 441, 298, and 67 were due to cardiovascular (CV), non-CV, and unknown causes, respectively. Cumulative CV mortality at 3 years was higher with lower eGFR (Q1, 15.5%; Q2, 11.1%; Q3, 11.2%; Q4, 10.3%; P<0.001) or higher PCR (Q1, 15.2%; Q2, 12.3%; Q3, 11.7%; Q4, 9.0%; P<0.001). Similarly, non-CV mortality was higher with lower eGFR (Q1, 12.7%; Q2, 8.4%; Q3, 6.7%; Q4, 6.1%; P<0.001) or higher PCR (Q1, 10.3%; Q2, 7.9%; Q3, 9.4%; Q4, 6.4%; P=0.01). Sudden death was 1.7-fold higher with lower eGFR (P=0.04) and 2.1-fold higher with higher PCR (P<0.001). Infection-related mortality was 3.3-fold higher in the lowest eGFR quartile (P<0.001) and 2.8-fold higher in the highest PCR quartile (P<0.02). The overall proportion of CV and non-CV deaths was not significantly different across eGFR or PCR quartiles.

LIMITATIONS

Results may not be generalizable to nondiabetic CKD or diabetic CKD in the absence of anemia. Measured GFR was not available.

CONCLUSIONS

In diabetic CKD, both lower baseline GFR and higher PCR are associated with higher CV and non-CV mortality rates, particularly from sudden death and infection. Efforts to improve outcomes should focus on CV disease and early diagnosis and treatment of infection.

Prophylactic distal revascularization with interval ligation and simultaneous arteriovenous fistula creation in high-risk patients

Dialysis access-related ischemic steal syndrome is a well-recognized dialysis access complication. When severe, manifestations include rest pain, hand dysfunction, and tissue loss. Dialysis access attempts on the affected extremity are usually abandoned after a diagnosis of steal syndrome, and patients are often left catheter-dependent. Prophylactic distal revascularization with interval ligation has been described in patients at high-risk for steal syndrome. We present our experience with prophylactic distal revascularization with interval ligation performed simultaneously with arteriovenous fistula creation to prevent the recurrence in five patients and review the current body of literature supporting its use.

Intraoperative balloon angioplasty using fogarty artertial embolectomy balloon catheter for creation of arteriovenous fistula for hemodialysis: single center experience

Background

The purpose of this study was to evaluate the use of a Fogarty arterial embolectomy catheter (Fogarty catheter) in intraoperative balloon angioplasty of the cephalic vein, in order to determine its effect on the patency of arteriovenous fistulas (AVFs) created for hemodialysis access.

Methods

A total of 156 patients who underwent creation of an AVF were divided into two groups, based whether a Fogarty catheter was used during AVF creation. Group A (89 patients) comprised the patients who underwent balloon angioplasty with a Fogarty catheter during the operation. Group B (67 patients) included the patients in whom a Fogarty catheter was not used during the operation. Patient records were reviewed retrospectively and documented. The patency rate was determined by the Kaplan-Meier method.

Results

The records of 156 patients who underwent the creation of an AVF from January 2007 to October 2011 were included. The mean follow-up duration was 40.2±19.4 months (range, 1 to 97 months). The patency rates in group A at 12, 36, and 72 months were 83.9%±3.9%, 78.3%±4.6%, and 76.3%±4.9%, respectively, while the corresponding patency rates in group B were 92.5%±3.2%, 82.8%±0.5%, and 79.9%±5.7%, respectively. The patency rates in group B were found to be slightly higher than those in group A, but the difference was not statistically significant (p=0.356).

Conclusion

Intraoperative balloon angioplasty of the cephalic vein using the Fogarty catheter is a simple and easily reproducible procedure, and it can be helpful in increasing AVF patency in cases of insufficient runoff or a suboptimal cephalic vein.

Maintaining safety in the dialysis facility

Errors in dialysis care can cause harm and death. While dialysis machines are rarely a major cause of morbidity, human factors at the machine interface and suboptimal communication among caregivers are common sources of error. Major causes of potentially reversible adverse outcomes include medication errors, infections, hyperkalemia, access-related errors, and patient falls. Root cause analysis of adverse events and "near misses" can illuminate care processes and show system changes to improve safety. Human factors engineering and simulation exercises have strong potential to define common clinical team purpose, and improve processes of care. Patient observations and their participation in error reduction increase the effectiveness of patient safety efforts.

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.

Vascular access creation before hemodialysis initiation and use: a population-based cohort study

BACKGROUND AND OBJECTIVES

In Canada, approximately 17% of patients use an arteriovenous access (fistula or arteriovenous graft) at commencement of hemodialysis, despite guideline recommendations promoting its timely creation and use. It is unclear if this low pattern of use is attributable to the lack of surgical creation or a high nonuse rate.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using large health care databases in Ontario, Canada, a population-based cohort of adult patients (≥18 years old) who initiated hemodialysis as their first form of RRT between 2001 and 2010 was studied. The aims were to (1) estimate the proportion of patients who had an arteriovenous access created before starting hemodialysis and the proportion who successfully used it at hemodialysis start, (2) test for secular trends in arteriovenous access creation, and (3) estimate the effect of late nephrology referral and patient characteristics on arteriovenous access creation.

RESULTS

There were 17,183 patients on incident hemodialysis. The mean age was 65.8 years, 60% were men, and 40% were referred late to a nephrologist; 27% of patients (4556 of 17,183) had one or more arteriovenous accesses created, and the median time between arteriovenous access creation and hemodialysis start was 184 days. When late referrals were excluded, 39% of patients (4007 of 10,291) had one or more arteriovenous accesses created, and 27% of patients (2724 of 10,291) used the arteriovenous access. Since 2001, there has been a decline in arteriovenous access creation before hemodialysis initiation. Women, higher numbers of comorbidities, and rural residence were consistently associated with lower rates of arteriovenous access creation. These results persisted even after removing patients with <6 months nephrology care or who had AKI 6 months before starting hemodialysis.

CONCLUSIONS

In Canada, arteriovenous access creation before hemodialysis initiation is low, even among patients followed by a nephrologist. Better understanding of the barriers and influencers of arteriovenous access creation is needed to inform both clinical care and guidelines.

Upper limb vascular calcification score as a predictor of mortality in diabetic hemodialysis patients

OBJECTIVE

This study evaluated the correlation between an upper limb vascular calcification (Vc) score (VcS) and late all-cause mortality in diabetic hemodialysis patients with distal upper limb arteries medial wall sclerosis (Mönckeberg disease).

METHODS

We retrospectively reviewed Vc in bilateral upper limb plain radiographs and in duplex ultrasound images performed before radial-cephalic fistula (RCF) creation in diabetic hemodialysis patients. Only medial linear calcifications outlining the vessel wall were considered positive on X-ray images, whereas for ultrasound reviews, only continuous highly echogenic plaques producing bright white echos with shadowing were considered to be medial calcification. A VcS was then applied in each patient. Every half of each of the three main arterial conduits (brachial, radial, and ulnar arteries) in each arm was counted as 1 if it contained ≥ 6 cm of linear calcification, whereas absence of calcification or minimum calcification (length <6 cm) was counted as 0. Long-term all-cause mortality was compared between patients with a low or moderate VcS <8 (group I), patients with a high VcS ≥ 8 (group II), and patients with VcS = 0 (control group). Kaplan-Meier statistics were used for comparisons among the groups.

RESULTS

Nineteen patients had a VcS <8, 21 had VcS ≥ 8, and 43 patients had VcS = 0. The study patients had a mean age of 68 ± 10 years (range, 42-83 years; P = .23). Before early conversion to a RCF, dialysis therapy in 59 (71.1%) had already been initiated through central venous catheters (CVCs). The mean follow-up for groups I, II, and controls was 41.4 ± 41.2 months (range, 4-144 months), 34.15 ± 31.3 months (range, 1-108 months), and 66.7 ± 32.5 months (range, 12-126 months), respectively (P = .0009). Forty-seven patients died during the follow-up period (12 in group II and 24 in the controls; P = .88). Survival rates at 12, 24, 36, and 48 months were 78.3%, 65.7%, 54.8%, and 48.1% for group I; 75.2%, 58.8%, 49.3%, and 42% for group II; and 97.7%, 93.1%, 76.8%, and 71.8% for the control group, respectively (P = .013 for all groups; P = .044 for group II vs controls). Patients with (subgroups) or without CVCs at baseline had similar late mortality rates. Patients with CVCs/Vc had lower survival rates than those with CVCs/no Vc at 1 year (73.3% vs 96.5%) and at 3 years (47.7% vs 75.8%; P = .038). CVCs were related to increased risk of death only in subgroup II patients compared with the subcontrol group patients (75.4% vs 37.9% at 5 years, respectively; P = .034).

CONCLUSIONS

Diabetic hemodialysis patients exposed to high levels of upper extremity arterial medial VcSs upon receiving RCFs have an increased long-term mortality risk compared with diabetic hemodialysis patients with no Vc and receiving the same access. Patients with CVCs/Vc had the lowest survival rates.

Catheter-related atrial thrombus: tip of the iceberg?

Although guidelines recommend catheters as a last resort for establishing a vascular access in patients undergoing dialysis, they continue to be used widely for this purpose. Catheter-related atrial thrombus (CRAT) is rarely reported in this group of patients, and it can lead to serious complications. The aim of this study was to determine the incidence of CRAT in patients undergoing hemodialysis with permanent-tunneled catheters. A total of 50 patients undergoing hemodialysis with permanent catheters were included in this study. The diagnosis of CRAT was based on transthoracic echocardiography findings. Thrombus was present in nine patients (18%) and related to the tip of the catheter in all cases. Except for one patient with two foci of thrombus, all patients had a single focus. There were no significant associations between the development of thrombus and the duration of catheter use or the location of the catheter. Furthermore, catheter-related atrial thrombus did not appear to have a significant effect on mortality. The asymptomatic character of CRAT can be responsible for the low reporting rates, and its exact role in increased mortality and morbidity related with catheter use remains unknown. While planning management strategies, information on different options for vascular access routes and possible catheter-related complications should be provided to all patients who will undergo dialysis, together with a discussion involving other replacement alternatives for end-stage renal disease.