Outcomes of Elderly Patients after Predialysis Vascular Access Creation

Prospective Analysis of Arteriovenous Fistula Performance in the Context of Competing Risks

Background:

Many patients with newly created arteriovenous fistulas (AVF) may die before the AVF is needed for hemodialysis. However, formal competing risks frameworks are rarely used to report AVF patency, which may lead to biased estimates. We sought to identify the proportion of newly created AVF experiencing primary non-function and to describe long-term patency using a competing risk framework.

Methods:

We did a prospective observational study in 257 adults with newly created AVF in Alberta, Canada. The primary outcome was primary non-function. Secondary outcomes included loss of primary-patency, loss of assisted primary-patency, and loss of secondary functional-patency. Results were presented using icon-array plots to form the basis for future decision aids.

Results:

Participants were 63.0% male with mean age 62.3 years and median follow-up of 18.5 months (range 0.02-180 months). Of 257 participants, 50 could not be assessed for function or primary non-function, usually due to death. Of the remaining 207, 102 (49.3%) had primary non-function, and function was ultimately established for 142 (68.6%). Thus, only 142 of the 257 participants (55.3%) ultimately used the AVF for hemodialysis. High rates of competing risks led to biased results from Kaplan-Meier analyses of lost patency. When accounting for competing risks, loss of primary-patency among AVF with established function was 36.6%, 65.5% and 66.2%, at 1y, 3y and 5y respectively.

Conclusions:

Only 55% of fistulas were ultimately used for hemodialysis when accounting for competing risks and primary non-function. These results and the icon-array plots may inform discussions surrounding vascular access options for patients.

Clinical impact of the Kidney Failure Risk Equation for vascular access planning

BACKGROUND

Risk-based thresholds for arteriovenous (AV) access creation has been proposed to aid vascular access planning. We aimed to assess the clinical impact of implementing the Kidney Failure Risk Equation (KFRE) for vascular access referral.

METHODS

A total of 16 102 nephrology-referred chronic kidney disease (CKD) patients from the Swedish Renal Registry 2008-18 were included. The KFRE was calculated repeatedly, and the timing was identified for when the KFRE risk exceeded several pre-defined thresholds and/or the estimated glomerular filtration rate was <15 mL/min/1.73 m2 (eGFR15). To assess the utility of the KFRE/eGFR thresholds, cumulative incidence curves of kidney replacement therapy (KRT) or death, and decision-curve analyses were computed at 6 and 12 months, and 2 years. The potential impact of using the different thresholds was illustrated by an example from the Swedish access registry.

RESULTS

The 12-month specificity for KRT initiation was highest for KFRE >50% {94.5 [95% confidence interval (CI) 94.3-94.7]} followed by KFRE >40% [90.0 (95% CI 89.7-90.3)], while sensitivity was highest for KFRE >30% [79.3 (95% CI 78.2-80.3)] and eGFR <15 mL/min/1.73 m2 [81.2 (95% CI 80.2-82.2)]. The 2-year positive predictive value was 71.5 (95% CI 70.2-72.8), 61.7 (95% CI 60.4-63.0) and 47.2 (95% CI 46.1-48.3) for KFRE >50%, KFRE >40% and eGFR <15, respectively. Decision curve analyses suggested the largest net benefit for KFRE >40% over 2 years and KFRE >50% over 12 months when it is important to avoid the harm of possibly unnecessary surgery. In Sweden, 54% of nephrology-referred patients started hemodialysis in a central venous catheter (CVC), of whom only 5% had AV access surgery >6 months before initiation. Sixty percent of the CVC patients exceeded KFRE >40% a median of 0.8 years (interquartile range 0.4-1.5) before KRT initiation.

CONCLUSIONS

The utility of using KFRE >40% and KFRE >50% is higher compared with the more traditionally used eGFR threshold <15 mL/min/1.73 m2 for vascular access planning.

Planning vascular access creation: The promising role of the kidney failure risk equation

BACKGROUND

Planning for vascular access (VA) creation is essential in pre-dialysis patients although optimal timing for VA referral and placement is debatable. Guidelines suggest referral when eGFR is 15-20 mL/min/1.73 m2. This study aimed to validate the use of kidney failure risk equation (KFRE) in VA planning.

METHODS

Retrospective analysis of all adult patients with CKD who were referred for first VA placement, namely AVF or AVG, at a tertiary center, between January 2018 and December 2019. The four-variable KFRE was calculated. Start of KRT, mortality, and VA placement were assessed in a 2-year follow-up. We used Cox regression to predict KRT start and calculated the ROC curve.

RESULTS

256 patients were included and 64.5% were male, mean age was 70.4 ± 12.9 years and mean eGFR was 16.09 ± 10.43 mL/min/1.73 m2. One hundred fifty-nine patients required KRT (62.1%) and 72 (28.1%) died in the 2-year follow-up. The KFRE accurately predicted KRT start within 2-years (38.3 ± 23.8% vs 17.6 ± 20.9%, p < 0.001; HR 1.05 95% CI (1.06-1.12), p < 0.001), with an auROC of 0.788 (p < 0.001, 95% CI (0.733-0.837)). The optimal KFRE cut-off was >20%, with a HR of 9.2 (95% CI (5.06-16.60), p < 0.001). Patients with KFRE ⩾ 20% had a significant lower mean time from VA consult to KRT initiation (10.8 ± 9.4 vs 15.6 ± 10.3 months, p < 0.001). On a sub-analysis of patients with an eGFR < 20 mL/min/1.73 m2, a KFRE ⩾ 20% was also a significant predictor of 2-year start of KRT, with an HR of 6.61 (95% CI (3.49-12.52), p < 0.001).

CONCLUSION

KFRE accurately predicted 2-year KRT start in this cohort of patients. A KFRE ⩾ 20% can help to establish higher priority patients for VA placement. The authors suggest referral for VA creation when eGFR < 20 mL/min/1.73 m2 and KFRE ⩾ 20%.

Uncovering Patient and Caregiver Goals for Goal-Concordant Care in Kidney Therapy Decisions

CONTEXT

In kidney therapy (KT) decisions, goal-concordant decision-making is recognized to be important, yet alignment with patients' goals during dialysis initiation is not always achieved.

OBJECTIVES

To explore older patients' and caregivers' hopes, goals, and fears related to KT and communication of these elements with members of their health care team.

METHODS

The study included patients aged ≥75 years with an estimated glomerular filtration rate ≤25 mL/min/1.73 m2 and their caregivers enrolled in a palliative care intervention for KT decision-making. Patients and caregivers were asked open-ended questions about their hopes, goals, and fears related to KT decisions. A survey assessed if patients shared their goals with members of their health care team. Qualitative data underwent content analysis, supplemented by demographic descriptive statistics.

RESULTS

The mean age of patients (n = 26) was 82.7 (±5.7) years, and caregivers (n = 15) had a mean age of 66.4 (±13.7) years. Among the participants, 13 patients and 11 caregivers were women, and 20 patients and 12 caregivers were White. Four themes emerged: (1) Maintaining things as good as they are by avoiding dialysis-related burdens; (2) seeking longevity while avoiding dialysis; (3) avoiding pain, symptoms, and body disfigurement; and (4) deferring decision-making. Patients rarely had shared their goals with the key members of their health care team.

CONCLUSION

Patients and caregivers prioritize maintaining quality of life, deferring decision-making regarding dialysis, and avoiding dialysis-related burdens. These goals are often unshared with their family and health care teams. Given our aging population, urgent action is needed to educate clinicians to actively explore and engage with patient goals in KT decision-making.

Association between Timing of Vascular Access Creation and Mortality in Patients Initiating Hemodialysis: A Nationwide Cohort Study in Japan

INTRODUCTION

The optimal time for vascular access (VA) creation remains controversial.

METHODS

We conducted a cohort study using data from the Japanese Society for Dialysis Therapy Renal Data Registry. Adult patients who started receiving hemodialysis in 2007 and had a permanent VA created were included. The exposure of interest was the timing of VA creation, categorized into three groups: early VA creation (defined as creation at least 4 months before hemodialysis initiation), just prior VA creation (creation between 1 and 3 months before hemodialysis initiation), and late VA creation (creation within 1 month of or after hemodialysis initiation). Cox regression analyses were used to compare 1-year all-cause mortality, with late VA creation as the reference group. Owing to the violations of the proportional hazards assumptions, the follow-up period was divided into "early" (1-4 months follow-up) and "late" (5-12 months follow-up) periods.

RESULTS

Overall, 1,280 (15.4%) of 8,322 patients died. Both early creation and just prior creation were associated with lower all-cause mortality in the early period compared with late creation. In the late period, the hazard ratios (HRs) for all-cause mortality decreased with earlier VA creation (adjusted HRs [95% confidence intervals]: 0.49 [0.35-0.67] for the early creation group and 0.63 [0.51-0.79] for the just prior creation group).

CONCLUSION

Our study suggests that VA creation at least 1 month before hemodialysis initiation is associated with lower all-cause mortality in the early period, with earlier VA creation resulting in further mortality reduction in the late period.

A decade of arteriovenous fistula creations in the ⩾75 years population: Equal opportunity or sub-optimal use of resources

BACKGROUND

The optimal vascular access in the elderly remains contentious in the context of increasingly limited resources and anticipated survival on hemodialysis. Research focus has shifted to include the impact of vascular access on quality of life. This study explored clinical outcomes in individuals aged ⩾75 years who had an arteriovenous fistula (AVF) created in a single center over a 10-year period.

MATERIALS AND METHODS

Demographic and clinical data concerning AVFs created January 2009-December 2019 were identified from a prospective database for retrospective analysis. Outcome measures were AVF patency and failure to mature rates plus overall patient and vascular access survival. The Vascular Access Specific Quality of life measure (VASQoL) was completed in a contemporary cohort aged ⩾75 years established on HD in October 2021.

RESULTS

AVF outcomes were available for 272 patients (93%). The failure to mature (FTM) rate was 36% with the significant predictors of AVF FTM being the creation of a radiocephalic AVF (OR 8.13, 95% CI 8.02-8.52, p < 0.01), female gender (OR 4.84, 95% CI 4.70-5.41, p < 0.01), and a history of peripheral vascular disease (OR 5.25, 95% CI 5.22-6.00, p value = 0.02). Functional patency was associated with a median 12-month survival benefit compared to those whose fistula FTM (p < 0.01). The median patency duration for a functionally patent AVF was 3 years. Elderly patients with a fistula reported a lower quality of life in VASQoL scoring than those with central venous catheters.

CONCLUSIONS

In this cohort, AVF creation in individuals aged ⩾75 years AVFs was associated with comparable AVF patency rates to younger patients. AVF functional patency was associated with superior patient survival compared to those with AVF FTM. A multi-disciplinary surveillance program may help reduce AVF loss. Further work on how vascular access choice impacts quality of life in elderly patients is required.

Arteriovenous access creation and hazards of hospitalization and death in patients starting hemodialysis

BACKGROUND

Recent evidence suggests an overestimation of the benefits associated with arteriovenous (AV) fistula versus graft in certain populations. We assessed hazards of all-cause and cause-specific hospitalization and death associated with AV access type in patients who started hemodialysis with a catheter in France, overall and by subgroups of age, sex and comorbidities.

METHODS

We performed a target trial emulation including patients who initiated hemodialysis with a catheter from 2010 through 2018 and were followed by the REIN Registry. We identified first-created fistula or graft through the French national health-administrative database. We used joint frailty models to deal with recurrent hospitalizations and potential informative censoring by death, and inverse probability weighting to account for confounding.

RESULTS

From the 18 800 patients included (mean age 68 ± 15 years, 35% women), 5% underwent AV graft creation first. The weighted hazard ratio (wHR) of all-cause hospitalization associated with graft was 1.08 [95% confidence interval (CI) 1.02 to 1.15], that of vascular access-related hospitalization was 1.43 (95% CI 1.32 to 1.55), and those of cardiovascular- and infection-related hospitalizations were 1.14 (95% CI 1.03 to 1.26) and 1.11 (95% CI 0.97 to 1.28), respectively. Results were consistent for most subgroups, except that the highest hazard of all-cause, cardiovascular- and infection-related hospitalizations with graft was blunted in patients with comorbidities (i.e. diabetes, wHR 1.01, 95% CI 0.93 to 1.10; 1.10, 95% CI 0.96 to 1.26; and 0.94, 95% CI 0.78 to 1.12, respectively).

CONCLUSIONS

In patients starting hemodialysis with a catheter, AV graft creation is associated with increased hazard of vascular access-related hospitalizations compared with fistula. This may not be the case for death or other causes of hospitalization.

Evaluation of arteriovenous fistula maturation and early prediction of clinical eligibility, using ultrasound: The Fistula Maturation Evaluation (FAME) Study

INTRODUCTION

The study of time-related alterations of ultrasound-determined parameters during maturation, and the assessment of time to hemodynamic maturation, enabling early prediction of clinical eligibility, of hemodialysis autologous arteriovenous fistulae (AVF).

METHODS

This is an observational, prospective, study of only AVF-eligible patients referred for access creation, from 02/2019 to 02/2022 (ClinicalTrials.gov identifier: NCT0473687). Brachial artery diameter (dBA), access flow volume (FV), non-augmented efferent vein diameter (dEV), resistivity index (RI), and efferent vein total wall thickness (tEV), were assessed by ultrasound. Measurements were conducted daily in the first week and repeated on days 14, 21, 30, 60, and 90, postoperatively. The primary endpoint included the documentation of serial changes of flow and structural parameters related to AVF maturation in the first 90 days of the post-operative period and maturation early prediction. Secondary endpoints included the determination of factors affecting maturation.

RESULTS

One hundred one participants (mean age, 67 ± 6 years; 76 males) were enrolled. Average dBA and FV reached maximum on day 60 (5.64 ± 0.85 mm) and 90 (1.172 ± 617 mL/min), respectively. Day 7 values of dBA (5.48 ± 0.73 mm) and FV (1.039 ± 531 mL/min) did not alter significantly during the follow-up period. Parameters indicative of clinical functionality, dEV (5.82 ± 0.90 mm) and tEV (0.493 ± 0.10 mm), reached approximately 90% of maximum (6.66 ± 1.42 mm and 0.526 ± 0.11 mm), by day 14. RI reached minimum on day 30 (0.46 ± 0.09), without significant changes after day 2 (0.48 ± 0.09, p = 0.284). A significant correlation was identified, between day 7 FV and day 60 dEV (r = 0.40, p = 0.0002). A FV cut-off value ⩾657.51 mL/min, on day 7, predicted successful fistula maturation with 85% sensitivity and 100% specificity. Multivariate analysis identified female gender, age >75, diabetes, and wrist access as independent predictors of decreased values of maturation parameters.

CONCLUSION

Hemodynamic maturation is completed by the first postoperative week, while AVF is clinically functional, by the second. FV can be used for early prediction of maturation.

Dialysis for older adults: why should the targets be different?

The number of patients aged > 75-years treated by dialysis continues to increase, particularly in developed countries. Haemodialysis is a well-established treatment with national and international clinical guidelines designed to provide patients with optimal treatment. However, these were developed when the dialysis population was younger, and less co-morbid. This change in patient demographics questions whether these guideline targets still apply to older patients. More patients now start dialysis with residual kidney function and could benefit from a less frequent dialysis schedule. Older patients have a lower thirst drive, so lower interdialytic gains, reduced appetite, muscle mass and physical activity would potentially allow starting dialysis with less frequent sessions a practical option. Similarly, patients with residual kidney function and lower metabolic activity may not need to meet current dialyser Kt/Vurea clearance targets to remain healthy. Instead, some elderly patients may be at risk of malnutrition and might need liberalisation of the low salt, potassium and phosphate dietary restrictions, or even additional supplements to ensure adequate protein intake. Although a fistula is the preferred vascular access, a forearm fistula may not be an option due to vascular disease, while a brachial fistula can potentially compromise cardiovascular reserve, so a dialysis catheter becomes the de facto access, especially in patients with limited life expectancy. Thus, clinical guideline targets designed for a younger less co-morbid dialysis population may not be equally applicable to the older patient initiating dialysis, and so a more individualised approach to dialysis prescription and vascular access is required.

Shared decision making in elderly patients with kidney failure

'Elderly' is most commonly defined as an individual aged 65 years or older. However, this definition fails to account for the differences in genetics, lifestyle and overall health that contribute to significant heterogeneity among the elderly beyond chronological age. As the world population continues to age, the prevalence of chronic diseases, including chronic kidney disease (CKD), is increasing and CKD frequently progresses to kidney failure. Moreover, frailty represents a multidimensional clinical entity highly prevalent in this population, which needs to be adequately assessed to inform and support medical decisions. Selecting the optimal treatment pathway for the elderly and frail kidney failure population, be it haemodialysis, peritoneal dialysis or conservative kidney management, is complex because of the presence of comorbidities associated with low survival rates and impaired quality of life. Management of these patients should involve a multidisciplinary approach including doctors from various specialties, nurses, psychologists, dieticians and physiotherapists. Studies are mostly retrospective and observational, lacking adjustment for confounders or addressing selection and indication biases, making it difficult to use these data to guide treatment decisions. Throughout this review we discuss the difficulty of making a one-size-fits-all recommendation for the clinical needs of older patients with kidney failure. We advocate that a research agenda for optimization of the critical issues we present in this review be implemented. We recommend prospective studies that address these issues, and systematic reviews incorporating the complementary evidence of both observational and interventional studies. Furthermore, we strongly support a shared decision-making process matching evidence with patient preferences to ensure that individualized choices are made regarding dialysis vs conservative kidney management, dialysis modality and optimal vascular access.

Predialysis Vascular Access Placement and Catheter Use at Hemodialysis Initiation

BACKGROUND

Current guidelines encourage placement of an arteriovenous (AV) fistula in patients with advanced CKD to avoid initiation of hemodialysis with a central venous catheter. However, the relative merits of predialysis placement of an AV fistula or graft have been poorly studied.

METHODS

This study included 380 patients (mean age 59±14 years, 73% Black patients, 51% male) from a large academic medical center who underwent predialysis placement of an AV fistula (286) or AV graft (94). The study quantified three end points: time from access placement to initiation of dialysis, likelihood of starting hemodialysis without a catheter, and number of vascular access procedures before dialysis initiation.

RESULTS

The eGFR at access surgery was <10, 10-14, and ≥15 ml/min per 1.73 m 2 in 87 (23%), 179 (47%), and 114 (30%) patients, respectively. The median time from access surgery to hemodialysis initiation was 69, 156, and 429 days in patients with an eGFR of <10, 10-14, and ≥15 ml/min per 1.73 m 2 , respectively ( P < 0.001). Hemodialysis was initiated within 2 years of access surgery in 298 (78%) of the patients. Catheter-free hemodialysis initiation was higher in patients with an AV graft versus an AV fistula when the eGFR was <10 ml/min per 1.73 m 2 (88% versus 43%; odds ratio [OR], 9.10 [95% confidence interval, 2.74 to 26.4]) and when the eGFR was 10-14 ml/min per 1.73 m 2 (88% versus 54%; OR, 6.05 [2.35 to 15.0]) but similar when the eGFR was ≥15 ml/min per 1.73 m 2 (90% versus 75%; OR, 3.00 [0.48 to 34.9]). Patients undergoing an AV fistula were more likely to undergo an angioplasty (11% versus 0%, P < 0.001), surgical access revision (26% versus 8%, P < 0.001), a second access placement (16% versus 6%, P = 0.02), and a catheter insertion (32% versus 11%, P < 0.001).

CONCLUSIONS

Among patients with CKD undergoing vascular access surgery when their eGFR was <15 ml/min per 1.73 m 2 , catheter use at dialysis initiation was much less likely when an AV graft, rather than an AV fistula, was placed.

Hemodialysis vascular access in elderly patients: A comprehensive review

The number of elderly patients initiating hemodialysis (HD) increased considerably over the past decade. Arteriovenous fistulas (AVFs) are the preferred vascular access (VA) type in most HD patients. Choice of VA for older hemodialysis patients presents a challenge. The higher incidence of comorbidities, longer AVF maturation times, risk of primary failure, risk of patency loss, and shorter life expectancy are important factors to consider. In this review we provide a comprehensive analysis on maturation rates, primary failure, patency, and mortality regarding vascular access in patients older than 75 years of age.

The reasons for comparative effectiveness clinical trials of arteriovenous fistula versus graft strategy in older adults on hemodialysis with a catheter

Clinicians and patients are guided by observational studies to make one of the most consequential decisions for patients with advanced kidney disease: the selection of the "right" hemodialysis vascular access. More than a decade ago, a call for randomized clinical trials was made to equitably compare clinical outcomes between arteriovenous (AV) fistulas (AVFs) and AV grafts (AVGs). Mounting evidence suggests that trade-offs between AVF- and AVGrelated outcomes are context dependent. In this article, we summarize four streams of evidence that collectively underpin the burden of equipoise between the two types of AV access in older adults with comorbidities who are on hemodialysis with a central venous catheter.

Central venous catheter-related complications in older haemodialysis patients: A multicentre observational cohort study

BACKGROUND

Central venous catheters (CVC) remain a commonly used vascular access option in haemodialysis, despite guidelines advising to preferably use arteriovenous fistulae. Compared to younger patients, the risk-benefit ratio of CVC in older patients might be more beneficial, but previous studies mainly focussed on catheter-related bacteraemia and/or assessed tunnelled CVC (TCVC) only. This study's aim was to compare all catheter-related infections and malfunctions in older patients with younger patients using all CVC subtypes.

MATERIALS AND METHODS

We used data from DUCATHO, a multicentre observational cohort study in The Netherlands. All adult patients in whom a CVC was placed for haemodialysis between 2012 and 2016 were included. The primary endpoint was the occurrence of catheter-related infections, comparing patients aged ⩾70 years with patients aged <70 years (reference). As secondary endpoints, catheter malfunctions and catheter removal due to either infection or malfunction were assessed. Using Cox proportional hazards and recurrent events modelling, hazard ratios (HR) with 95% confidence intervals (CI) were calculated with adjustment of prespecified confounders. Additionally, endpoints were assessed for non-tunnelled CVC (NTCVC) and TCVC separately.

RESULTS

A total of 1595 patients with 2731 CVC (66.5% NTCVC, 33.1% TCVC) were included. Of these patients, 1001 (62.8%) were aged <70 years and 594 (37.2%) ⩾70 years. No statistically significant difference was found for the occurrence of catheter-related infections (adjusted HR 0.80-95% CI 0.62-1.02), catheter malfunction (adjusted HR 0.94-95% CI 0.75-1.17) and catheter removal due to infection or malfunction (adjusted HR 0.94-95% CI 0.80-1.11). Results were comparable when assessing NTCVC and TCVC separately.

CONCLUSION

Patients aged ⩾70 to <70 years have a comparable risk for the occurrence of catheter-related infections and catheter malfunction. These findings may help when discussing treatment options with older patients starting haemodialysis and may inform the current debate on the best vascular access for these patients.

Vascular access type and mortality in elderly incident hemodialysis patients

INTRODUCTION

The ideal vascular access type for elderly hemodialysis (HD) patients remains debatable. The aim of this study was to analyze the association between patterns of vascular access use within the first year of HD and mortality in elderly patients.

METHODS

Single-center retrospective study of 99 incident HD patients aged≥80 years from January 2010 to May 2021. Patients were categorized according to their patterns of vascular access use within the first year of HD: central venous catheter (CVC) only, CVC to arteriovenous fistula (AVF), AVF to CVC, and AVF only. Baseline clinical data were compared among groups. Survival outcomes were analyzed using Kaplan-Meier survival curves and Cox's proportional hazards model.

RESULTS

When compared with CVC to AVF, mortality risk was significantly higher among CVC only patients and similar to AVF only group [HR 0.93 (95% CI 0.32-2.51)]. Ischemic heart disease [HR 1.74 (95% CI 1.02-2.96)], lower levels of albumin [HR 2.16 (95% CI 1.28-3.64)] and hemoglobin [HR 4.10(95% CI 1.69-9.92)], and higher levels of c-reactive protein [HR 1.87(95% CI 1.11-3.14)] were also associated with increased mortality risk in our cohort, p<0.05.

CONCLUSION

Our findings suggested that placement of an AVF during the early stages of dialysis was associated with lower mortality compared to persistent CVC use among elderly patients. AVF placement appears to have a positive impact on survival outcomes, even in those who started dialysis with a CVC.

Dialysis Access Considerations in Kidney Palliative Care

In this review, we discuss common challenges at the interface between dialysis access planning, prognostication, and patient-centered decision making. Particularly for patients whose survival benefit from dialysis is attenuated by advanced age or other serious illness, knowing the potential complications and anticipated frequency of access procedures is essential for patients and families to be able to conceptualize what life on dialysis will look like. Although starting dialysis with a functioning graft or fistula is associated with reduced infection rates, mortality, hospitalizations, and cost compared with a central venous catheter, these benefits must be weighed against the chance that early access placement in an elderly or seriously ill patient is an unnecessary surgery because the chronic kidney disease never progresses, the patient dies before developing an indication to start dialysis, or, the patient prefers conservative kidney management over dialysis. Kidney palliative care is a growing subspecialty of nephrology focused on helping seriously ill patients navigate complex medical decisions, and may be useful for intensive goals-of-care discussions about treatment and access options for patients with limited anticipated survival because of age or other serious illness.

Hemodialysis Vascular Access and Risk of Major Bleeding, Thrombosis, and Cardiovascular Events: A Cohort Study

Rationale & Objective

The risks of major bleeding, thrombosis, and cardiovascular events are elevated in patients receiving maintenance hemodialysis (HD). Our objective was to compare the risk of these outcomes in HD according to the permanent vascular access type.

Study Design

Observational cohort study.

Setting & Participants

Using data from the United States Renal Data System (2010-2015), we included patients with kidney failure who were greater than 18 years, had Medicare as the primary payer, were not using an oral anticoagulant, and were newly using an arteriovenous (AV) access for HD.

Exposure

AV graft (AVG) or AV fistula (AVF).

Outcomes

Major bleeding, venous thromboembolism, ischemic stroke, myocardial infarction, cardiovascular death, and critical limb ischemia.

Analytical Approach

Comparing 17,763 AVG and 60,329 AVF users, we estimated the 3-year incidence rates and incidence rate ratios (IRRs) of each outcome using Poisson regression. IRRs were adjusted for sociodemographic and clinical covariates.

Results

The use of an AVG, compared with that of an AVF, was associated with an increased risk of venous thromboembolism (10.8 vs 5.3 events per 100 person-years; adjusted IRR, 1.74; 95% CI, 1.63-1.85) but not with the risk of major bleeding (IRR, 1.04; 95% CI, 0.93-1.17). The use of an AVG was also potentially associated with a slightly increased risk of cardiovascular death (IRR, 1.09; 95% CI, 1.01-1.16).

Limitations

This analysis focused on patients with a functioning AV access; adverse events that may occur during access maturation should also be considered when selecting a vascular access.

Conclusions

The use of an AVG, relative to an AVF, in HD is associated with an increased risk of venous thromboembolism. Given recent guidelines emphasizing selection of the “right access” for the “right patient,” the results of this study should potentially be considered as one additional factor when selecting the optimal access for HD.

Optimising Access Surgery in Senior Haemodialysis Patients (OASIS): study protocol for a multicentre randomised controlled trial

INTRODUCTION

Current evidence on vascular access strategies for haemodialysis patients is based on observational studies that are at high risk of selection bias. For elderly patients, autologous arteriovenous fistulas that are typically created in usual care may not be the best option because a significant proportion of fistulas either fail to mature or remain unused. In addition, long-term complications associated with arteriovenous grafts and central venous catheters may be less relevant when considering the limited life expectancy of these patients. Therefore, we designed the Optimising Access Surgery in Senior Haemodialysis Patients (OASIS) trial to determine the best strategy for vascular access creation in elderly haemodialysis patients.

METHODS AND ANALYSIS

OASIS is a multicentre randomised controlled trial with an equal participant allocation in three treatment arms. Patients aged 70 years or older who are expected to initiate haemodialysis treatment in the next 6 months or who have started haemodialysis urgently with a catheter will be enrolled. To detect and exclude patients with an unusually long life expectancy, we will use a previously published mortality prediction model after external validation. Participants allocated to the usual care arm will be treated according to current guidelines on vascular access creation and will undergo fistula creation. Participants allocated to one of the two intervention arms will undergo graft placement or catheter insertion. The primary outcome is the number of access-related interventions required for each patient-year of haemodialysis treatment. We will enrol 195 patients to have sufficient statistical power to detect an absolute decrease of 0.80 interventions per year.

ETHICS AND DISSEMINATION

Because of clinical equipoise, we believe it is justified to randomly allocate elderly patients to the different vascular access strategies. The study was approved by an accredited medical ethics review committee. The results will be disseminated through peer-reviewed publications and will be implemented in clinical practice guidelines.

TRIAL REGISTRATION NUMBER

NL7933.

PROTOCOL VERSION AND DATE

V.5, 25 February 2021.

De Novo Central Vein Stenosis in Hemodialysis Patients Following Initial Tunneled Central Vein Catheter Placement

Background

Central vein stenosis (CVS) is a common complication in hemodialysis patients following tunneled central venous catheter (CVC) insertion. Little is known about its incidence, association with patient characteristics, or relationship with duration of CVC placement. We systematically evaluated central vein stenosis in hemodialysis patients receiving their first CVC exchange at a large medical center.

Methods

All new hemodialysis patients underwent an ultrasound before their internal jugular tunneled CVC placement, to exclude venous stenosis or thrombosis. After the initial CVC insertion, if the patients were referred for CVC exchange due to dysfunction, a catheterogram/venogram was performed to assess for hemodynamically significant (≥50%) central vein stenosis. During a 5-year period (January 2016 to January 2021), we quantified the incidence of CVS in patients undergoing CVC exchange. We also evaluated the association of central vein stenosis with patient demographics, comorbidities, and duration of CVC dependence before exchange.

Results

During the study period, 273 patients underwent exchange of a tunneled internal jugular vein CVC preceded by a catheterogram/venogram. Hemodynamically significant CVS was observed in 36 patients (13%). CVS was not associated with patient age, sex, race, diabetes, hypertension, coronary artery disease, peripheral artery disease, or CVC laterality. However, the frequency of CVS was associated with the duration of CVC dependence (26% versus 11% for CVC duration ≥6 versus <6 months: odds ratio (95% CI), 3.17 (1.45 to 6.97), P=0.003).

Conclusions

Among incident hemodialysis patients receiving their first tunneled internal jugular CVC exchange, the overall incidence of de novo hemodynamically significant central vein stenosis was 13%. The likelihood of CVS was substantially greater in patients with at least 6 months of CVC dependence.

New Frontiers in Vascular Access Practice: From Standardized to Patient-tailored Care and Shared Decision Making

Vascular access planning is critical in the management of patients with advanced kidney disease who elect for hemodialysis for RRT. Policies put in place more than two decades ago attempted to standardize vascular access care around the model of optimal, namely arteriovenous fistula, and least preferred, namely central venous catheter, type of access. This homogenized approach to vascular access care emerged ineffective in the increasingly heterogeneous and complex dialysis population. The most recent vascular access guidelines acknowledge the limitations of standardized care and encourage tailoring vascular access care on the basis of patient and disease characteristics. In this article, we discuss available literature in support of patient-tailored access care on the basis of differences in vascular access outcomes by biologic and social factors-age, sex, and race. Further, we draw attention to the overlooked dimension of patient-reported preferences and shared decision making in the practice of vascular access planning. We discuss milestones to overcome as requisite steps to implement effective shared decision making in vascular access care. Finally, we take into consideration local practice cofactors as major players in vascular access fate. We conclude that a personalized approach to hemodialysis vascular access will require dynamic care specifically relevant to the individual on the basis of biologic factors, fluctuating clinical needs, values, and preferences.

Arteriovenous Access Type and Risk of Mortality, Hospitalization, and Sepsis Among Elderly Hemodialysis Patients: A Target Trial Emulation Approach

RATIONALE & OBJECTIVE

Evidence is mixed regarding the optimal choice of the first permanent vascular access for elderly patients receiving hemodialysis (HD). Lacking data from randomized controlled trials, we used a target trial emulation approach to compare arteriovenous fistula (AVF) versus arteriovenous graft (AVG) creation among elderly patients receiving HD.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Elderly patients included in the US Renal Data System who initiated HD with a catheter and had an AVF or AVG created within 6 months of starting HD.

EXPOSURE

Creation of an AVF versus an AVG as the incident arteriovenous access.

OUTCOMES

All-cause mortality, all-cause and cause-specific hospitalization, and sepsis.

ANALYTICAL APPROACH

Target trial emulation approach, high-dimensional propensity score and inverse probability of treatment weighting, and instrumental variable analysis using the proclivity of the operating physician to create a fistula as the instrumental variable.

RESULTS

A total of 19,867 patients were included, with 80.1% receiving an AVF and 19.9% an AVG. In unweighted analysis, AVF creation was associated with significantly lower risks of mortality and hospitalization, especially within 6 months after vascular access creation. In inverse probability of treatment weighting analysis, AVF creation was associated with lower incidences of mortality and hospitalization within 6 months after creation (hazard ratios of 0.82 [95% CI, 0.75-0.91] and 0.82 [95% CI, 0.78-0.87] for mortality and all-cause hospitalization, respectively), but not between 6 months and 3 years after access creation. No association between AVF creation and mortality, sepsis, or all-cause, cardiovascular disease-related, or infection-related hospitalization was found in instrumental variable analyses. However, AVF creation was associated with a lower risk of access-related hospitalization not due to infection.

LIMITATIONS

Potential for unmeasured confounding, analyses limited to elderly patients, and absence of data on actual access use during follow-up.

CONCLUSIONS

Using observational data to emulate a target randomized controlled trial, the type of initial arteriovenous access created was not associated with the risks of mortality, sepsis, or all-cause, cardiovascular disease-related, or infection-related hospitalization among elderly patients who initiated HD with a catheter.

Prevention of tunneled cuffed catheter dysfunction with prophylactic use of a taurolidine urokinase lock: A randomized double-blind trial

Background

The efficacy and cost-effectiveness of prophylactic thrombolytic locks in hemodialysis patients at high-risk of thrombotic dialysis catheter dysfunction is uncertain. We investigated this question in a double-blinded randomized controlled study.

Methods

Prevalent hemodialysis patients from 8 Belgian hemodialysis units, with ≥2 separate episodes of thrombotic dysfunction of their tunneled cuffed catheter during the 6 months before inclusion, were randomized to either: taurolidine heparin locks thrice weekly (control arm) or the same locks twice a week combined with taurolidine urokinase locks once a week before the longest interval without HD (TaurolockU arm). The primary efficacy outcome was the incidence rate of catheter thrombotic dysfunction requiring thrombolytic locks to restore function.

Results

68 hemodialysis patients (32 controls, 36 urokinase) were followed during 9875 catheter days between May 2015 and June 2017. Incidence rate of thrombotic catheter dysfunction was 4.8 in TaurolockU vs 12.1/1000 catheter days in control group (rate ratio 0.39; 95%CI 0.23–0.64). 15/36 (42%) catheters in the treatment group required at least one therapeutic urokinase lock vs 23/32 (72%) in the control group (P = 0.012). The two groups did not differ significantly in catheter-related bloodstream infection and combined cost of prophylactic and therapeutic catheter locks. The TaurolockU group had a numerically higher number of episodes of refractory thrombosis.

Conclusions

Prophylactic use of urokinase locks is highly effective in reducing the number of thrombotic catheter dysfunctions in catheters with a history of recurring dysfunction. Prophylactic use of urokinase locks did not reduce the overall costs associated with catheter locks and was associated with a numerically higher number of episodes of refractory thrombosis.

Trial registration

ClinicalTrials.gov Identifier: NCT02036255.

Arteriovenous Fistula Versus Graft Access Strategy in Older Adults Receiving Hemodialysis: A Pilot Randomized Trial

Background

It is unclear whether surgical placement of an arteriovenous (AV) fistula (AVF) confers substantial clinical benefits over an AV graft (AVG) in older adults with end-stage kidney disease (ESKD). We report vascular access outcomes of a pilot clinical trial.

Study Design

Pilot randomized parallel-group open-label trial.

Setting & Participants

Patients 65 years and older with ESKD and no prior AV access receiving maintenance hemodialysis through a tunneled central venous catheter referred for AV access placement by their treating nephrologist.

Intervention

Participants were randomly assigned in a 1:1 ratio to surgical placement of an AVG or AVF.

Outcomes

Index AV access primary failure, successful cannulation, adjuvant interventions and infections.

Results

Of 122 older adults receiving hemodialysis and no prior AV access surgery, 24% died before (n = 18) or were too sick for (n = 11) referral for a permanent AV access. Of 46 eligible patients, 36 (78%) consented and were randomly assigned to AVG (n = 18) and AVF (n = 18) placement, of whom 13 (72%) and 16 (89%) underwent index AV access surgical placement, respectively. At a median follow-up of 321.0 days, primary AV access failure was noted in 31% in each group. The proportion of patients with successful cannulation was 62% (8 of 13) in the AVG and 50% (8 of 16) in the AVF group; median times to successful cannulation were 75.0 and 113.5 days, respectively. Endovascular procedures were recorded in 38% and 44%, and surgical reinterventions, in 23% and 25%, respectively. AV access infection was seen in 3 (23%) and 2 (13%) patients, respectively.

Limitations

Small sample size precludes statistical inference.

Conclusions

Almost one-quarter of older adults with incident ESKD and a central venous catheter as primary access were not referred for AV access placement due to medical reasons. Based on these limited results, there is little reason to favor either an AVF or AVG in this population until results from a larger randomized clinical trial become available.

Funding

Government funding to an author (Dr Murea is supported by National Institutes of Health∖National Institute on Aging grant 1R03 AG060178-01).

Trial Registration

NCT03545113.

Predicted risk of renal replacement therapy at arteriovenous fistula referral in chronic kidney disease

BACKGROUND AND OBJECTIVES

Optimal timing of arteriovenous fistula placement in chronic kidney disease remains difficult and contributes to high central venous catheter use at initial hemodialysis. We tested whether a prediction model for progression to renal replacement therapy developed at Kaiser Permanente Northwest may help guide decisions about timing of referral for arteriovenous fistula placement.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

A total of 205 chronic kidney disease stage 4 patients followed by nephrology referred for arteriovenous fistula placement were followed for up to 2 years. Patients were censored if they died or discontinued Kaiser Permanente Northwest coverage. Survival analyses were performed for overall progression to renal replacement therapy divided by quartiles based on 2-year risk for renal replacement therapy and estimated glomerular filtrate rate at time of referral.

RESULTS

By 2 years, 60% progressed to renal replacement therapy and 11% had died. 80% in the highest risk versus 36% in the lowest risk quartile progressed to renal replacement therapy (predicted risk 84% vs 17%). 75% in the lowest estimated glomerular filtrate rate versus 56% in the highest estimated glomerular filtrate rate quartile progressed to renal replacement therapy (mean estimated glomerular filtrate rate 13 mL/min vs 21 mL/min). The hazard ratio was significantly higher for each consecutive higher renal replacement therapy quartile risk while for estimated glomerular filtrate rate, the hazard ratio was only significantly higher for the lowest compared to the highest quartile. The extreme quartile risk ratio was higher for 2-year risk for renal replacement therapy compared to estimated glomerular filtrate rate (4.0 vs 2.4).

CONCLUSION

In patients with chronic kidney disease stage 4 referred for arteriovenous fistula placement, 2-year renal replacement therapy risk better discriminated progression to renal replacement therapy compared to estimated glomerular filtrate rate at time of referral.

Early Predictors of Arteriovenous Fistula Maturation: A Novel Perspective on an Enduring Problem

BACKGROUND

Preoperative ultrasound mapping is routinely used to select vessels meeting minimal threshold diameters for surgical arteriovenous fistula (AVF) creation but fails to improve AVF maturation rates. This suggests a need to reassess the preoperative ultrasound criteria used to optimize AVF maturation.

METHODS

We retrospectively identified 300 catheter-dependent patients on hemodialysis with a new AVF created between 2010 and 2016. We then evaluated the associations of preoperative vascular measurements and hemodynamic factors with unassisted AVF maturation (successful use for dialysis without prior intervention) and overall maturation (successful use with or without prior intervention). Multivariable logistic regression was used to identify preoperative factors associated with unassisted and overall AVF maturation.

RESULTS

Unassisted AVF maturation associated with preoperative arterial diameter (adjusted odds ratio [aOR], 1.50 per 1-mm increase; 95% confidence interval [95% CI], 1.23 to 1.83), preoperative systolic BP (aOR, 1.16 per 10-mm Hg increase; 95% CI, 1.05 to 1.28), and left ventricular ejection fraction (aOR, 1.07 per 5% increase; 95% CI, 1.01 to 1.13). Overall AVF maturation associated with preoperative arterial diameter (aOR, 1.36 per 1-mm increase; 95% CI, 1.10 to 1.66) and preoperative systolic BP (aOR, 1.17; 95% CI, 1.06 to 1.30). Using receiver operating curves, the combination of preoperative arterial diameter, systolic BP, and left ventricular ejection fraction was fairly predictive of unassisted maturation (area under the curve, 0.69). Patient age, sex, race, diabetes, vascular disease, obesity, and AVF location were not associated with maturation.

CONCLUSIONS

Preoperative arterial diameter may be an under-recognized predictor of AVF maturation. Further study evaluating the effect of preoperative arterial diameter and other hemodynamic factors on AVF maturation is needed.

Endovascular Arteriovenous Dialysis Fistula Intervention: Outcomes and Factors Contributing to Fistula Failure

RATIONALE & OBJECTIVE

Primary patency is variable with arteriovenous fistulas, and many patients require angiographic procedures to obtain patency. Accordingly, we determined postintervention patency rates and contributing factors for fistula failure following intervention to establish secondary patency in non-dialysis-dependent patients with advanced chronic kidney disease following creation of an arteriovenous fistula.

STUDY DESIGN

Observational study from a single referral center.

SETTING & PARTICIPANTS

210 non-dialysis-dependent patients with advanced chronic kidney disease who underwent upper-extremity fistula creation for anticipated dialysis between October 1995 and January 2015 and who required subsequent endovascular therapy to establish or maintain patency were reviewed.

EXPOSURE

Endovascular therapy for dialysis arteriovenous fistula primary patency failure.

OUTCOMES

Postintervention patency duration following endovascular therapy.

ANALYTICAL APPROACH

Descriptive study with outcomes determined using Cox proportional hazards models.

RESULTS

Multiple fistula configurations were reviewed: 138 (65.7%) brachiocephalic, 39 (18.6%) radiocephalic, 30 (14.3%) brachiobasilic, 2 (1.0%) ulnocephalic, and 1 (0.5%) radiobasilic. There were 261 initial stenoses treated. Postintervention primary patency is defined as the time from the index intervention to repeat intervention for stenosis. Postintervention primary-assisted patency is the time from the index intervention to thrombectomy for fistula thrombosis or change in modality. Postintervention secondary patency is the time from the index intervention to fistula abandonment. Median postintervention primary patency, postintervention primary-assisted patency, and secondary patency were 2.7, 3.2, and 3.6 years, respectively. The overall 1-year primary, primary-assisted, and secondary patency rates in this cohort were 53.0%, 87.7%, and 83.5%, respectively. Compared with radiocephalic fistulas, brachiocephalic fistulas had higher risk for postintervention primary patency loss (HR, 1.90; 95% CI, 1.13-3.20; P = 0.02).

LIMITATIONS

Dialysis fistula revascularization techniques varied.

CONCLUSIONS

The radiocephalic fistula configuration had the best postintervention primary patency in this cohort. Postintervention primary-assisted patency and secondary patency were not significantly different among different fistula configurations.

Creation of arteriovenous fistula for hemodialysis in the older population

OBJECTIVE

To evaluate the results of arteriovenous fistula (AVF) created for haemodialysis in patients older than 65 years of age.

SUBJECTS AND METHODS

A retrospective analysis of patients with AVF or arteriovenous graft (AVG) creation, who were older than 65 years of age and were operated on at the II. Surgical Clinic at the University Hospital in Olomouc from 2014 - 2018 was performed.

RESULTS

212 patients were evaluated and a total of 239 AVF/AVG were created. 194 AVFs (81.18%) and 45 AVGs (18.82%) were created. Primary failure was seen in 19 arteriovenous fistulas (9.8%) and 2 arteriovenous grafts (4.44%). The primary patency of AVF was 69.9%, 62.8% after 12 and 24 months, respectively, and in the case of AVG it was 54.7% and 32.3% after 12 and 24 months, respectively. Primarily assisted patency of AVF was 77.6% and 66.3% after 12 and 24 months, respectively, and in case of AVG it was 69.1% and 39.7% after 12 and 24 months, respectively. Secondary patency of AVF was 77.6% and 66.3% after 12 and 24 months, respectively, and for AVG it was 69.1% and 39.7% after 12 and 24 months, respectively.

CONCLUSION

The type of vascular access should be selected based on a thorough, protocol-based examination. In most seniors, AVF is the method of choice. The AVG is a suitable choice for patients with an exhausted venous bed, in acute need of haemodialysis, in the elderly and in females. A "customized" approach should be matter of fact for older generations.

In-hospital mortality among incident hemodialysis older patients in Peru

BACKGROUND

Understanding the pattern of mortality linked to end stage renal disease (ESRD) is important given the increasing ageing population in low- and middle-income countries.

METHODS

We analyzed older patients with ESRD with incident hemodialysis, from January 2012 to August 2017 in one large general hospital in Peru. Individual and health system-related variables were analyzed using Generalized Linear Models (GLM) to estimate their association with in-hospital all-cause mortality. Relative risk (RR) with their 95% confidence intervals (95% CI) were calculated.

RESULTS

We evaluated 312 patients; mean age 69 years, 93.6% started hemodialysis with a transient central venous catheter, 1.7% had previous hemodialysis indication and 24.7% died during hospital stay. The mean length of stay was 16.1 days (SD 13.5). In the adjusted multivariate models, we found higher in-hospital mortality among those with encephalopathy (aRR 1.85, 95% CI 1.21-2.82 vs. without encephalopathy) and a lower in-hospital mortality among those with eGFR ≤7 mL/min (aRR 0.45, 95% CI 0.31-0.67 vs. eGFR>7 mL/min).

CONCLUSIONS

There is a high in-hospital mortality among older hemodialysis patients in Peru. The presence of uremic encephalopathy was associated with higher mortality and a lower estimated glomerular filtration rate with lower mortality.

Hemodialysis vascular access in the elderly-getting it right

Choosing the optimal hemodialysis vascular access for the elderly patient is best achieved by a patient-centered coordinated multidisciplinary team approach that aligns the patient's end-stage kidney disease Life-Plan, i.e., the individual treatment approach (supportive care, time-limited or long-term kidney replacement therapy, or combination thereof) and selection of dialysis modality (peritoneal dialysis versus hemodialysis) with the most suitable dialysis access. Finding the right balance between the patient's preferences, the likelihood of access function and survival, and potential complications in the context of available resources and limited patient survival can be extremely challenging. The framework for choosing the most appropriate vascular access for the elderly presented in this review considers the individual end-stage kidney disease Life-Plan, the patient life expectancy, the likelihood of access function and survival, the timing of dialysis relative to access placement, prior access history, and patient preference. This complex decision-making process should be dynamic in order to accommodate patients' changing needs and life and health circumstances. Effective and timely communication between the patient, their caregivers, and treating team is key to delivering truly patient-centered care. Delivering this care also requires overcoming the limitations of the currently available evidence that is predominantly based on observational data with its inherent risks of bias. While challenging, future randomized controlled studies exploring the risks, benefits, costs, and timing of placement of available access types in the elderly are required to help us "get it right" for our patients.

Initiation of maintenance hemodialysis through central venous catheters: study of patients' perceptions based on a structured questionnaire

Background

Despite well-publicized suggestions to utilize arteriovenous fistulae and grafts to initiate hemodialysis, too many patients in the United States start dialysis via central venous catheters despite their well-known association with increased morbidity, mortality, and cost.

Methods

To determine the reasons for this high rate of catheter use, and, ultimately, ways to reduce it, we developed a questionnaire designed to determine where in the process of patient care the process to fistula or graft placement was not completed, thus requiring the use of central venous catheters. The questionnaire was reviewed by several nephrologists not involved with the study. We administered the questionnaire to 52 consecutive hospitalized patients who started maintenance dialysis with catheters at a University-affiliated Hospital and referral center. The questionnaire asked each patient to provide details pertaining to pre-dialysis care, referrals, and follow-through on recommended referrals. If the patient did not see the physician to whom he/she was referred, we asked the reason(s) for such failure.

Results

Patient responses showed that there were two major lapses in the transition from diagnosis of advanced kidney disease to construction of appropriate dialysis access: failure by the patients to see a nephrologist and/or an access surgeon, and failure by physicians to refer patients to an access surgeon. Twenty percent of the patients failed to follow up with either a nephrologist or a surgeon. Only 38% (15/40) of those seen by a nephrologist had been referred to a surgeon.

Conclusions

The quality of care was impaired by lack of referral to surgeons by nephrologists and by lack of follow-through by patients. Areas for improvement include improved communications between physicians and patients and more careful follow-up by both physicians and patients. Several methods of providing better patient care and communication between patients and nephrologists are recommended.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1422-y) contains supplementary material, which is available to authorized users.

A randomized pilot study comparing graft-first to fistula-first strategies in older patients with incident end-stage kidney disease: Clinical rationale and study design

Timely placement of an arteriovenous (AV) vascular access (native AV fistula [AVF] or prosthetic AV graft [AVG]) is necessary to limit the use of tunneled central venous catheters (TCVC) in patients with end-stage kidney disease (ESKD) treated with hemodialysis (HD). National guidelines recommend placement of AVF as the AV access of first choice in all patients to improve patient survival. The benefits of AVF over AVG are less certain in the older adults, as age-related biological changes independently modulate patient outcomes. This manuscript describes the rationale, study design and protocol for a randomized controlled pilot study of the feasibility and effects of AVG-first access placement in older adults with no prior AV access surgery. Fifty patients age ≥65 years, with incident ESKD on HD via TCVC or advanced kidney disease facing imminent HD initiation, and suitable upper extremity vasculature for initial placement of an AVF or AVG, will be randomly assigned to receive either an upper extremity AVG-first (intervention) or AVF-first (comparator) access. The study will establish feasibility of randomizing older adults to the two types of AV access surgery, evaluate relationships between measurements of preoperative physical function and vascular access development, compare vascular access outcomes between groups, and gather longitudinal assessments of upper extremity muscle strength, gait speed, performance of activities of daily living, and patient satisfaction with their vascular access and quality of life. Results will assist with the planning of a larger, multicenter trial assessing patient-centered outcomes.

Timing of Fistula Creation and the Probability of Catheter-Free Use: A Cohort Study

Background:

Fistula creation is recommended to avoid the use of central venous catheters for hemodialysis. The extent to which timing of fistula creation minimizes catheter use is unclear.

Objective:

To compare patient outcomes of 2 fistula creation strategies: fistula attempt prior to the initiation of dialysis (“predialysis”) or fistula attempt after starting dialysis (“postinitiation”).

Design:

Cohort study.

Setting:

Five Canadian dialysis programs.

Patients:

Patients who started hemodialysis between 2004 and 2012, who underwent fistula creation, and were tracked in the Dialysis Measurement Analysis and Reporting (DMAR) system.

Measurements:

Catheter-free fistula use within 1 year of hemodialysis start, probability of catheter-free fistula use during follow-up, and rates of access-related procedures.

Methods:

Retrospective data analysis: logistic regression; negative binomial regression.

Results:

Five hundred and eight patients had fistula attempts predialysis and 583 postinitiation. At 1 year, 80% of those with predialysis attempts achieved catheter-free use compared to 45% with post-initiation attempts (adjusted odds ratio [OR]_preVSpost = 4.67; 95% confidence interval [CI] = 3.28-6.66). The average of all patient follow-up time spent catheter-free was 63% and 28%, respectively (probability of use per unit time, OR_preVSpost = 2.90; 95% CI = 2.18-3.85). This finding was attenuated when accounting for maturation time and when restricting the analysis to those who achieved catheter-free use. Predialysis fistula attempts were associated with lower procedure rates after dialysis initiation—1.61 procedures per person-year compared with 2.55—but had 0.65 more procedures per person prior to starting dialysis.

Limitations:

Observational design, unknown indication for predialysis and postinitiation fistula creation, and unknown reasons for prolonged catheter use.

Conclusions:

Predialysis fistula attempts were associated with a higher probability of catheter-free use and remaining catheter-free over time, and also resulted in fewer procedures compared with postinitiation attempts, which could be due to timing of attempt or patient factors. Catheter use and procedures were still common for all patients, regardless of the timing of fistula creation.

Timing of referral for vascular access for hemodialysis: Analysis of the current status and the barriers to timely referral

Introduction:

Current guidelines recommend the placement of vascular access 6 months before the anticipated start of hemodialysis therapy; however, many patients start hemodialysis using a central venous catheter. We investigated the timing of referral for vascular access, the vascular access type at hemodialysis initiation, and the barriers to a timely referral.

Methods:

The study involved a retrospective review of 237 patients for whom the first vascular access for hemodialysis was created between January and November 2017.

Results:

Among the 237 patients, 58.2% were referred before hemodialysis initiation, while 41.8% were referred after hemodialysis initiation. Among the 138 patients, 55, 59, and 24 patients were referred more than 6 months, between 2 and 6 months, and within 2 months before hemodialysis initiation, respectively. Within these subgroups, 3.6%, 10.2%, and 75.0% patients underwent hemodialysis initiation with a central venous catheter, respectively. Among the 99 patients referred after hemodialysis initiation, the reasons for late referral were as follows: unexpected rapid progression of kidney disease (n = 23), noncompliance (n = 21), late visit to the nephrologist (initial visit within 2 months of hemodialysis initiation; n = 14), change of treatment strategy from peritoneal dialysis or transplants (n = 9), and unknown reasons (n = 32).

Conclusion:

Only 23% of patients were referred for vascular access 6 months before the anticipated hemodialysis therapy. In addition, 53% of patients initiated hemodialysis with a central venous catheter. Avoidance of catheter insertion was mostly successful in patients referred 2 months before hemodialysis initiation. The most common modifiable barrier to the timely referral was noncompliance.

Predictive Parameters Functioning Arteriovenous Fistula for Hemodialysis in the Elderly

Elderly patients with end stage kidney disease represent a challenge for surgeons to create a vascular access.

Determine predictive parameters functionality of the arteriovenous fistulas for hemodialysis in the elderly.

The study was organized as a retrospective study at the Center for Dialysis, Clinic for Urology and Nephrology, Clinical Center Kragujevac. The study included patients older than 65 years with arteriovenous fistula thrombosis, in the period of four years, in which there is information on the length of the functioning fistula. The study included 48 patients, mean age 71.3±5.2 years, 29 (60%) men and 19 (40%) women. The data were analyzed according to gender and demographic structure, type of anastomosis, positioning, length of functioning fistulas, and the lumen diameter of the arteries and veins that are used to create a fistula.

The median length of functioning arteriovenous fistula, based on Kaplan-Meier model, is 16 months (95% CI 6.9-25.1). Median functioning for proximaly located fistulas was 24 months (range, 1-259), while median functioning in patient with distally located fistulas was 8 months (range, 1-96). The difference in relation to the positioning of the fistula was statistically significant (p=0.006). In univariate Cox regression model, a statistically significant predictor of the functioning of arteriovenous fistulae is fistula positioning (B=0.700; p=0.022).

The predictive parameter of survival of arteriovenous fistulas in elderly is proximally located fistula.

Autologous arteriovenous fistula is associated with superior outcomes in elderly hemodialysis patients

BACKGROUND

The number of elderly patients with end-stage renal disease is increasing rapidly. The higher prevalence of comorbidities and shorter life expectancy in these patients make it difficult to decide on the type of vascular access (VA). We explored the optimal choice for VA in elderly hemodialysis patients.

METHODS

We included elderly patients (> 65 years) visiting our VA clinic and divided them into three groups as follows: radiocephalic arteriovenous fistula (AVF), brachiocephalic AVF, and prosthetic arteriovenous graft (AVG). The primary outcomes were VA abandonment and all-cause mortality. The secondary outcome was maturation failure (MF).

RESULTS

Of 529 patients, 61.2% were men. The mean age was 73.6 ± 6.0 years. The VA types were as follows: 49.9% radiocephalic AVF, 31.8% brachiocephalic AVF, and 18.3% AVG. Patients with an AVG tended to be older, female, and have a lower body mass index. More than half of patients (n = 302, 57.1%) started dialysis with central catheters, but the proportion of predialysis central catheter placement was not different among the VA types. Radiocephalic AVF was significantly superior to AVG in terms of VA abandonment (P = 0.005) and all-cause mortality (P < 0.001) in spite of a higher probability of MF. Brachiocephalic AVF was associated with a shorter time to the first needling and fewer interventions before maturation than radiocephalic AVF.

CONCLUSIONS

Autologous AVF was suggested as the preferred VA choice in terms of long-term outcomes in elderly patients.

Should a fistula first policy be revisited in elderly haemodialysis patients?

Life-sustaining haemodialysis requires a durable vascular access (VA) to the circulatory system. The ideal permanent VA must provide longevity for use with minimal complication rate and supply sufficient blood flow to deliver the prescribed dialysis dosage. Arteriovenous fistulas (AVFs) have been endorsed by many professional societies as the VA of choice. However, the high prevalence of comorbidities, particularly diabetes mellitus, peripheral vascular disease and arterial hypertension in elderly people, usually make VA creation more difficult in the elderly. Many of these patients may have an insufficient vasculature for AVF maturation. Furthermore, many AVFs created prior to the initiation of haemodialysis may never be used due to the competing risk of death before dialysis is required. As such, an arteriovenous graft and, in some cases, a central venous catheter, become a valid alternative form of VA. Consequently, there are multiple decision points that require careful reflection before an AVF is placed in the elderly. The traditional metrics of access patency, failure and infection are now being seen in a broader context that includes procedure burden, quality of life, patient preferences, morbidity, mortality and cost. This article of the European Dialysis (EUDIAL) Working Group of ERA-EDTA critically reviews the current evidence on VA in elderly haemodialysis patients and concludes that a pragmatic patient-centred approach is mandatory, thus considering the possibility that the AVF first approach should not be an absolute.

Planning and evaluation for vascular access in the elderly

Vascular access is of vital importance for patients requiring dialysis therapies. AV fistulas have been endorsed by many professional societies as the access of choice, however, subsequent creation does not go without consequences. As the population ages and patients become more medically complex, access failure has become a major cause of treatment complication. For the elderly, this is especially true and there are multiple decision points that require careful reflection before an AVF is placed. This article reviews access considerations for AVF placement in the elderly population and considers the possibility that the fistula first approach to vascular access should not be an absolute.

Definitions and End Points for Interventional Studies for Arteriovenous Dialysis Access

This paper is part of the Clinical Trial Endpoints for Dialysis Vascular Access Project of the American Society of Nephrology Kidney Health Initiative. The purpose of this project is to promote research in vascular access by clarifying trial end points which would be best suited to inform decisions in those situations in which supportive clinical data are required. The focus of a portion of the project is directed toward arteriovenous access. There is a potential for interventional studies to be directed toward any of the events that may be associated with an arteriovenous access' evolution throughout its life cycle, which has been divided into five distinct phases. Each one of these has the potential for relatively unique problems. The first three of these correspond to three distinct stages of arteriovenous access development, each one of which has been characterized by objective direct and/or indirect criteria. These are characterized as: stage 1-patent arteriovenous access, stage 2-physiologically mature arteriovenous access, and stage 3-clinically functional arteriovenous access. Once the requirements of a stage 3-clinically functional arteriovenous access have been met, the fourth phase of its life cycle begins. This is the phase of sustained clinical use from which the arteriovenous access may move back and forth between it and the fifth phase, dysfunction. From this phase of its life cycle, the arteriovenous access requires a maintenance procedure to preserve or restore sustained clinical use. Using these definitions, clinical trial end points appropriate to the various phases that characterize the evolution of the arteriovenous access life cycle have been identified. It is anticipated that by using these definitions and potential end points, clinical trials can be designed that more closely correlate with the goals of the intervention and provide appropriate supportive data for clinical, regulatory, and coverage decisions.

Association of Proteinuria with Central Venous Catheter Use at Initial Hemodialysis

CONTEXT

Central venous catheter (CVC) use is associated with increased mortality and complications in hemodialysis recipients. Although prevalent CVC use has decreased, incident use remains high.

OBJECTIVE

To examine characteristics associated with CVC use at initial dialysis, specifically looking at proteinuria as a predictor of interest.

DESIGN

Retrospective cohort of 918 hemodialysis recipients from Kaiser Permanente Northwest who started hemodialysis from January 1, 2004, to January 1, 2014.

MAIN OUTCOME MEASURES

Multivariable logistic regression was used to examine an association of proteinuria with the primary outcome of CVC use.

RESULTS

More than one-third (36%) of patients in our cohort started hemodialysis with an arteriovenous fistula, and 64% started with a CVC. Proteinuria was associated with starting hemodialysis with a CVC (likelihood ratio test, p < 0.001) after adjustment for age, peripheral vascular disease, congestive heart failure, diabetes, sex, race, and length of predialysis care. However, on pairwise comparison, only patients with midgrade proteinuria (0.5-3.5 g) had lower odds of starting hemodialysis with a CVC (odds ratio = 0.39, 95% confidence interval = 0.24-0.65).

CONCLUSION

Proteinuria was associated with use of CVC at initial hemodialysis. However, a graded association did not exist, and only patients with midgrade proteinuria had significantly lower odds of CVC use. Our findings suggest that proteinuria is an explanatory finding for CVC use but may not have pragmatic value for decision making. Patients with lower levels of proteinuria may have a higher risk of starting dialysis with a CVC.

Central venous catheters for chronic hemodialysis: Is "last choice" never the "right choice"?

Since the publication of the first vascular access clinical practice guidelines in 1997, the global nephrology community has dedicated significant time and resources toward increasing the prevalence of arteriovenous fistulas and decreasing the prevalence of central venous catheters for hemodialysis. These efforts have been bolstered by observational studies showing an association between catheter use and increased patient morbidity and mortality. To date, however, no randomized comparisons of the outcomes of different forms of vascular access have been conducted. There is mounting evidence that much of the difference in patient outcomes may be explained by patient factors, rather than choice of vascular access. Some have called into question the appropriateness of fistula creation for certain patient populations, such as those with limited life expectancy and those at high risk of fistula-related complications. In this review, we explore the extent to which catheters and fistulas exhibit the characteristics of the "ideal" vascular access and highlight the significant knowledge gaps that exist in the current literature. Further studies, ideally randomized comparisons of different forms of vascular access, are required to better inform shared decision making.

Predictors of nonfunctional arteriovenous access at hemodialysis initiation and timing of access creation: A registry-based study

Determinants of nonfunctional arteriovenous (AV) access, including timing of AV access creation, have not been sufficiently described. We studied 29 945 patients who had predialysis AV access placement and were included in the French REIN registry from 2005 through 2013. AV access was considered nonfunctional when dialysis began with a catheter. We estimated crude and adjusted odds ratio (OR) with 95% confidence intervals (CI) of nonfunctional versus functional AV access associated with case-mix, facility characteristics, and timing of AV access creation. Analyses were stratified by dialysis start condition (planned or as an emergency) and comorbidity profile. Overall, 18% patients had nonfunctional AV access at hemodialysis initiation. In the group with planned dialysis start, female gender (OR 1.43, 95% CI 1.32–1.56), diabetes (OR 1.28, 95% CI 1.15–1.44), and a higher number of cardiovascular comorbidities (OR 1.27, 95% CI 1.09–1.49, and 1.31, 1.05–1.64, for 3 and >3 cardiovascular comorbidities versus none, respectively) were independent predictors of nonfunctional AV access. A higher percentage of AV access creation at the region level was associated with a lower rate of nonfunctional AV access (OR 0.98, 95% CI 0.98–0.99 per 1% increase). The odds of nonfunctional AV access decreased as time from creation to hemodialysis initiation increased up to 3 months in nondiabetic patients with fewer than 2 cardiovascular comorbidities and 6 months in patients with diabetes or 2 or more such comorbidities. In conclusion, both patient characteristics and clinical practices may play a role in successful AV access use at hemodialysis initiation. Adjusting the timing of AV access creation to patients’ comorbidity profiles may improve functional AV access rates.

Advanced age is not a barrier to creating a functional arteriovenous fistula: a retrospective study

INTRODUCTION

Arteriovenous fistulas (AVFs) are the recommended form of vascular access for hemodialysis. However, controversy exists regarding whether AVFs are suitable for elderly patients.

METHODS

Single-center retrospective review to investigate the impact of age on AVF outcomes. Five hundred and twenty-five patients with AVF creation were stratified based on age <65, 65-75, and >75 years. AVF outcomes including primary failure, AVF patency (primary, secondary, and functional), and AVF complications were studied for 3 years following AVF creation.

RESULTS

The cohort was 63% male, 44% Caucasian, and 55% had diabetes or cardiovascular disease. 39% were aged <65 years, 33% 65-75 years, and 28% were aged >75 years. No differences in rates of primary failure, loss of primary patency, complications, or need for intervention were observed between age groups. There was a significant association of age with secondary patency and functional patency, with age >75 being an independent risk factor for shortened lifespan of the fistula. For patients aged >75 years, secondary patency at 3 years was 64% compared to 75%-78% for younger patients. Functional patency at 2 years was 69% for those aged >75 years compared to 78%-81% for younger patients.

CONCLUSIONS

We found no difference in AVF maturation, primary patency, complications, or interventions in those over the age of 75 compared to younger counterparts. While secondary and functional patency rates were significantly lower in those aged >75 years, the magnitude of difference is likely not clinically relevant. Therefore, we recommend that advanced age alone should not preclude patients from AVF creation.

Dialysis Access as an Area of Improvement in Elderly Incident Hemodialysis Patients: Results from a Cohort Study from the International Monitoring Dialysis Outcomes Initiative

BACKGROUND

Commencing hemodialysis (HD) using a catheter is associated with a higher risk of adverse outcomes, and early conversion from central-venous catheter (CVC) to arteriovenous fistula/graft (non-CVC) improves outcomes. We investigated CVC prevalence and conversion, and their effects on outcomes during the first year of HD in a multinational cohort of elderly patients.

METHODS

Patients ≥70 years from the MONDO Initiative who commenced HD between 2000 and 2010 in Asia-Pacific, Europe, North-, and South-America and survived at least 6 months were included in this investigation. We stratified by age (70-79 years [younger] vs. ≥80 years [older]) and compared access types (at first and last available date) and their changes. We studied the association between access at initiation and conversion, respectively, and all-cause mortality using Kaplan-Meier curve and Cox regression, and predicted the absence of conversion from catheter to non-CVC using adjusted logistic regression.

RESULTS

In 14,966 elderly, incident HD patients, survival was significantly worse when using a CVC at all times. In Europe, the conversion frequency from CVC to non-CVC was higher in the younger fraction. Conversion from non-CVC to CVC was associated with worsened outcomes only in the older fraction.

CONCLUSION

These results corroborate the need for early HD preparation in the elderly HD population. Treatment of elderly patients who commence HD with a CVC should be planned considering aspects of individual clinical risk assessment. Differences in treatment practices in predialysis care specific to the elderly as a population may influence access care and conversion rate.

Fistula and Survival Outcomes after Fistula Creation among Predialysis Chronic Kidney Disease Stage 5 Patients

BACKGROUND

Most guidelines recommend the creation of arteriovenous fistula (AVF) in patients with chronic kidney disease (CKD) stage 4. However, an increasing number of studies suggest that early AVF creation leads to high rates of AVF failure and death before dialysis commencement. Only the Japanese guideline recommends AVF creation at CKD stage 5; however, no data are available regarding access-related outcomes at this stage.

METHOD

This was a multicenter cohort study involving Japanese CKD stage 5 patients who underwent preemptive AVF creation from 2009 to 2013. The primary outcome was unnecessary AVF creation, defined as death before requiring dialysis or AVF failure before dialysis commencement. The secondary outcome was dialysis commencement. The associations with candidate predictors and the outcomes were examined.

RESULTS

A total of 303 patients were registered. Four cases of death before dialysis and 13 cases of AVF failure before dialysis commencement were observed. A total of 283 patients who advanced to dialysis were found to have functional AVFs. The cumulative incidences of unnecessary AVF creation and dialysis commencement at 1 year were 4.8 and 89.3%, respectively. Competing risk regression analyses showed that age ≥75 years (subhazard ratio [SHR] 3.12, 95% CI 1.20-8.09) and female gender (SHR 3.31, 95% CI 1.20-9.09) were associated with unnecessary AVF creation.

CONCLUSIONS

A low incidence of unnecessary AVF creation was revealed among Japanese patients who received AVF at CKD stage 5. These results may help clarify the natural history of unnecessary AVF creation for other countries reformatting their guidelines regarding late vascular access creation.