Examining the Association between Hemodialysis Access Type and Mortality: The Role of Access Complications

Risk factors for thrombosis in dialysis patients: A comprehensive systematic review and meta-analysis

AIM

To identify the factors associated with thrombosis in dialysis patients.

BACKGROUND

Thrombosis is a leading cause of vascular access failure in dialysis patients. Numerous risk factors contribute to thrombosis in this population.

METHODS

A systematic search was conducted across international databases using standardized keywords. The quality of the selected studies was assessed using the STROBE and CONSORT checklists. The findings were summarized in a Garrard table. Meta-analysis was performed using CMA software. The study adhered to the guidelines outlined in the PRISMA statement.

RESULTS

A total of 180 articles were reviewed. The odds ratio for thrombosis in patients with arteriovenous grafts compared to arteriovenous fistulas was 10.93 (95 % CI: 9.35-12.78), demonstrating statistical significance (P = 0.001). Similarly, hemodialysis patients had an odds ratio of thrombosis 3.60 times higher than non-hemodialysis patients (95 % CI: 3.54-4.19), with statistical significance (P = 0.001). Patients undergoing single-stage basilic vein transposition had a 1.89 times higher risk of thrombosis compared to those undergoing two-stage transposition (95 % CI: 1.04-3.46), also demonstrating statistical significance (P = 0.038).

CONCLUSIONS

Thrombosis in patients with end-stage renal disease undergoing dialysis was significantly associated with various factors, including graft access, single-stage basilic vein transposition, and hemodialysis. Additional contributing factors to thrombosis included diabetes, elevated homocysteine levels, female gender, age over 50, access location, and low access blood flow velocity. The analysis revealed a higher incidence of thrombosis in end-stage renal disease patients undergoing hemodialysis compared to those not undergoing dialysis, as well as in patients with arteriovenous grafts compared to those with arteriovenous fistulas. These findings underscore the importance of recognizing and managing these risk factors to prevent thrombotic events and enhance patient care within the dialysis setting.

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.

Patients, healthcare providers, and general population preferences for hemodialysis vascular access: a discrete choice experiment

Background

A patient-centered dialysis treatment option requires an understanding of patient preferences for alternative vascular accesses and nephrologists often face difficulties when recommending vascular access to end-stage kidney disease (ESKD) patients. We aimed to quantify the relative importance of various vascular access characteristics to patients, healthcare providers and general population, and how they affect acceptability for patients and healthcare providers.

Methods

In a discrete choice experiment, patients with maintenance hemodialysis (MHD), healthcare providers, and individuals from the general population were invited to respond to a series of hypothetical vascular access scenarios that differed in five attributes: cumulative patency, infection rate, thrombosis rate, cost, and time to maturation. We estimated the respondents' preference heterogeneity and relative importance of the attributes with a mixed logit model (MXL) and predicted the willingness to pay (WTP) of respondents via a multinomial logit model (MNL).

Results

Healthcare providers (n = 316) and the general population (n = 268) exhibited a favorable inclination toward longer cumulative patency, lower access infection rate and lower access thrombosis rate. In contrast, the patients (n = 253) showed a preference for a 3-year cumulative patency, 8% access infection rate, 35% access thrombosis rate and 1.5 access maturity time, with only the 3-year cumulative patency reaching statistical significance. Among the three respondent groups, the general population found cumulative patency less important than healthcare providers and patients did. Patients demonstrated the highest WTP for cumulative patency, indicating a willingness to pay an extra RMB$24,720(US$3,708) for each additional year of patency time.

Conclusion

Patients and healthcare providers had a strong preference for vascular access with superior patency. While the general population preferred vascular access with lower thrombosis rates. These results indicate that most patients prefer autogenous arteriovenous fistula (AVF) as an appropriate choice for vascular access due to its superior patency and lower complications than other vascular access types.

Characteristics of Vascular Access Cannulation Complications in End Stage Kidney Disease Patients in West Java from 2018 to 2022: A Retrospective Observational Study

Background

End-stage kidney disease (ESKD) is associated with a tremendous financial burden. Data in Indonesia shows an increasing number of patients with ESKD taking hemodialysis as a routine procedure every year. Establishment and maintenance of vascular access are important in the management of ESKD. Vascular complications that often arise due to hemodialysis are common and one of the main reasons for hospitalization. Cannulation complications ranged from minor hematomas to acute bleeding from pseudoaneurysms that required emergency surgical procedures. This study aims to assess the different clinicopathological characteristics of ESKD patients with vascular access cannulation complications and the surgical management related to the complications.

Materials and Methods

This research is a retrospective observational study. The research subjects in this study were ESKD patients in the vascular and endovascular surgery division of the tertiary hospital in West Java, Indonesia. There were 121 study subjects. Clinicopathological characteristics of vascular cannulation complications and surgical management are extracted from the medical record.

Results

Three major vascular complications were ruptured pseudoaneurysms 64/121 (52.9%), impending rupture pseudoaneurysms 28/121 (23.1%), and pseudoaneurysms 21/121 (17.4%). Common surgical procedures were ligation of the draining vein 47/121 (38.8%), arterial primary repair 28/121 (23.1%), and arterial patch repair 18/121 (14.9%). There was a significant relationship between symptoms of bleeding in ruptured pseudoaneurysms and bulging masses in pseudoaneurysms (p = 0.001). There was a significant relationship between the diameter of the vascular mass, vascular defect size, and hematoma and the type of surgical procedure taken (p < 0.010).

Conclusion

Ruptured, impending rupture, and pseudoaneurysms are major complications of vascular access in ESKD patients, and there was a significant relationship between the carried-out surgical procedure and the size of the vascular mass, defect, and hematoma.

Efficacy and safety of Apixaban for the prevention of thrombosis in arteriovenous grafts

This research aims to fill a vital gap in existing studies by evaluating the efficacy and safety of Apixaban, a direct oral anticoagulant, in the prevention of arteriovenous graft (AVG) thrombosis, thereby offering substantial insights into alternative anticoagulant options for hemodialysis patients. Conducted as a multi-center, randomized, double-blind, placebo-controlled trial, this study involved end-stage renal disease (ESRD) patients who had recently received polytetrafluoroethylene grafts. Participants were assigned to receive either Apixaban at a dose of 2.5 mg twice daily or a placebo. The primary outcome measure was the occurrence of graft thrombosis, while secondary outcomes focused on the incidence and severity of bleeding. Analytical methods included Kaplan-Meier estimates, Cox proportional hazards models, and conventional statistical tests. With 96 patients enrolled, the study found that Apixaban significantly reduced the incidence of AVG thrombosis compared to placebo (16.7% vs. 62.5%, P < 0.0001). Notably, this reduction in thrombosis incidence was not accompanied by an increase in bleeding events, thus affirming the safety profile of Apixaban as established in prior research. Apixaban is identified as an efficacious alternative to traditional anticoagulants in the prevention of AVG thrombosis among hemodialysis patients, representing a notable advancement in the care of individuals with ESRD. The results of this study support further investigations into the optimal dosing strategies specifically tailored for this patient demographic.

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.

Alignment Among Patient, Caregiver, and Health Care Provider Perspectives on Hemodialysis Vascular Access Decision-Making: A Qualitative Study

Background

Updates to the Kidney Disease Outcomes Quality Initiative Clinical Practice Guideline for Vascular Access emphasize the "right access, in the right patient, at the right time, for the right reasons." Although this implies a collaborative approach, little is known about how patients, their caregivers, and health care providers engage in vascular access (VA) decision-making.

Objective

To explore how the perspectives of patients receiving hemodialysis, their caregivers, and hemodialysis care team align and diverge in relation to VA selection.

Design

Qualitative descriptive study.

Setting

Five outpatient hemodialysis centers in Calgary, Alberta.

Participants

Our purposive sample included 19 patients receiving maintenance hemodialysis, 2 caregivers, and 21 health care providers (7 hemodialysis nurses, 6 VA nurses, and 8 nephrologists).

Methods

We conducted semi-structured interviews with consenting participants. Using an inductive thematic analysis approach, we coded transcripts in duplicate and characterized themes addressing our research objective.

Results

While participants across roles shared some perspectives related to VA decision-making, we identified areas where views diverged. Areas of alignment included (1) optimizing patient preparedness-acknowledging decisional readiness and timing, and (2) value placed on trusting relationships with the kidney care team-respecting decisional autonomy with guidance. Perspectives diverged in the following aspects: (1) differing VA priorities and preferences-patients' emphasis on minimizing disruptions to normalcy contrasted with providers' preferences for fistulas and optimizing biomedical parameters of dialysis; (2) influence of personal and peer experience-patients preferred pragmatic, experiential knowledge, whereas providers emphasized informational credibility; and (3) endpoints for VA review-reassessment of VA decisions was prompted by access dissatisfaction for patients and a medical imperative to achieve a functioning access for health care providers.

Limitations

Participation was limited to individuals comfortable communicating in English and from urban, in-center hemodialysis units. Few informal caregivers of people receiving hemodialysis and younger patients participated in this study.

Conclusions

Although patients, caregivers, and healthcare providers share perspectives on important aspects of VA decisions, conflicting priorities and preferences may impact the decisional outcome. Findings highlight opportunities to bridge knowledge and readiness gaps and integrate shared decision-making in the VA selection process.

Guidelines on vascular access for hemodialysis from the Brazilian Society of Angiology and Vascular Surgery

Chronic kidney disease is a worldwide public health problem, and end-stage renal disease requires dialysis. Most patients requiring renal replacement therapy have to undergo hemodialysis. Therefore, vascular access is extremely important for the dialysis population, directly affecting the quality of life and the morbidity and mortality of this patient population. Since making, managing and salvaging of vascular accesses falls within the purview of the vascular surgeon, developing guideline to help specialists better manage vascular accesses for hemodialysis if of great importance. Thus, the objective of this guideline is to present a set of recommendations to guide decisions involved in the referral, evaluation, choice, surveillance and management of complications of vascular accesses for hemodialysis.

Infectious outcomes of fibrin sheath disruption in tunneled dialysis catheters

BACKGROUND AND OBJECTIVES

Fibrin sheath (FS) formation around tunneled central venous catheters (CVC) increases the risk of catheter-related bloodstream infections due to bacterial adherence to a biofilm. We sought to investigate whether FS disruption (FSD) at the time of CVC removal or exchange affects infectious outcomes in patients with CVC-related infections.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Retrospective cohort study of 307 adult maintenance hemodialysis patients aged 18 years or older at a single center academic-based hemodialysis program (UHN, Toronto) who developed CVC-related infections requiring CVC removal or exchange between January 2000 and January 2019. Exposure was FSD at the time of CVC removal or exchange. Outcomes were infectious metastatic complications, recurrent infection with the same organism within 1 year, or death due to infection. We created a Markov Multi-State Model (MMSM) to assess patients' trajectories through time as they transitioned between states. A time-to-event analysis was performed, adjusted for clinically relevant factors.

RESULTS

There was no significant relationship between FSD status at the time of CVC removal, the development of infectious complications in the multivariable model (adjusted HR = 0.71, 95% CI 0.09-5.80, p = 0.76), or mortality from infection (HR = 0.84, 95% CI 0.34-2.11, p = 0.73).

CONCLUSIONS

FSD at the time of CVC removal was not associated with increased risk of infectious complications or death due to infection. Further prospective study is needed to determine whether FSD contributes to reducing CVC infectious related complications.

The impact of vascular access type on survival in haemodialysis: time for a paradigm shift? A prospective cohort study

INTRODUCTION

Although arteriovenous autologous fistula is the vascular access of choice due to better long-term outcome than central venous catheters, the use of central venous catheters is increasing. Our study aims to describe the survival and epidemiological features of a cohort of dialysis patients with a focus on the role of vascular access.

METHODS

Our study comprises a follow-up period from 2001 to 2020 in a single center. Descriptive analysis was performed on baseline data. Moreover, we analysed predictive variables of death with univariable and multivariable logistic regressions. Predictors of survival were analysed by univariable and multivariable Cox regression.

RESULTS

Our analysis includes 754 patients undergoing chronic haemodialysis. In the multivariable logistic regression, the use of tunnelled catheters resulted protective against death from any cause (Odds Ratio 0.43; p = 0.017). In the multivariable Cox analysis, being "late referral" was associated with decreased survival in the first 6 months since haemodialysis start (Hazard Ratio 3.79; p = 0.001). In the subgroup of elderly (age ≥ 75 years) patients (n = 201/472) with a follow up of 7-60 months, multivariable logistic regression showed that tunnelled catheters at the start of haemodialysis were associated with lower mortality (Odds Ratio, 0.25; p = 0.021), whereas vascular disease was found to be the main risk factor for death (Odds Ratio, 5.11; p = 0.000). Moreover, vascular disease was confirmed as the only independent risk factor by Cox analysis (Hazard Ratio, 1.58; p = 0.017).

CONCLUSIONS

In our cohort, mortality was found to be more closely associated with comorbidities than with the type of vascular access. Tunnelled central venous catheters might be a viable option for haemodialysis patients.

Assessment of dysfunctional tunneled hemodialysis catheters and outcome of endovascular salvage techniques: a simple solution to a complex problem

Objective

The aim of this study was to evaluate the causes of the dysfunctional tunneled cuffed catheters (TCCs) using multi-spiral computed tomography venography (MSCTV), and to analyze the outcomes of endovascular salvage techniques.

Material and methods

This retrospective review data from 27 patients who experienced TCC dysfunction between July 1, 2016 and January 31, 2021 was conducted. Patients' demographic data, clinical signs and symptoms, and imaging data were collected from interventional radiology database.

Results

MSCTV showed a range of abnormalities in the hemodialysis (HD) patients, including central venous occlusion (n = 4), fibrin sheath formation (n = 3), malposition of the catheter tips (n = 4), central venous perforation (n = 1), thrombus formation (n = 12), regular catheter exchange without determined lesions (n = 3). Interventional catheter salvage procedures were performed, such as catheter exchange, balloon disruption of a fibrin sheath, angioplasty for central vein stenosis, and stent deployment. The technical success rate for catheter insertions was 100%, and no procedure-related severe complications were observed. The 30-day catheter patency for all assessable catheters was 85.2%.

Conclusion

The use of MSCTV showed abnormal findings in almost 88.9% of cases concerning dysfunctional TCC. In this study, the examined appropriate endovascular techniques were found to be safe and technically successful, with a low incidence of procedure-related complications.

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.

Squamous cell carcinoma on an arteriovenous fistula scar: case report

The main type of access used for hemodialysis is the arteriovenous fistula (AVF) because it offers superior patency and lower complication rates when compared to other hemodialysis accesses. We report the case of a 69-year-old female patient with chronic kidney disease on dialysis secondary to hypertensive nephrosclerosis with a radiocephalic AVF in the left upper limb created 9 years previously. Two years previously, she had undergone a kidney transplant and was taking immunosuppressants. A crusted lesion developed on her left forearm with onset 3 months before presentation and she underwent an excisional biopsy that revealed a well-differentiated and superficially invasive squamous cell carcinoma, with lateral and deep surgical margins free from neoplasia. At 1-year follow-up, the patient showed no signs of neoplastic recurrence.

National Trends in Complications of Vascular Access for Hemodialysis and Analysis of Racial Disparities Among Patients With End-Stage Renal Disease in the Inpatient Setting

Introduction

The aim of this study is to assess the trends in access-related complications, as well as the impact of race on these complications, among admitted patients with end-stage kidney disease (ESKD) receiving hemodialysis.

Methods

A retrospective cohort study between 2005 and 2018 was performed using the National Inpatient Sample (NIS). Hospitalizations involving ESKD and hemodialysis were identified. There were 9,246,553 total admissions involving ESKD and hemodialysis, of which 1,167,886 (12.6%) had complications. Trends in complications were assessed and compared among races.

Results

There was a decreasing trend in rates of mechanical (trend: -0.05% per year; P < 0.001), inflammatory or infectious (-0.48%; P < 0.001), and other (-0.19%; P < 0.001) complications from 2005 to 2018. Non-White patients had a greater magnitude in the decrease in trends in rates of complications compared to White patients (-0.69% per year vs. -0.57%; P < 0.001). Compared to the White patients, Black patients (odds ratio [OR]: 1.26; P < 0.001) and those of the other races (OR: 1.11; P < 0.001) had higher odds of complications. These differences were also statistically significant among lower socioeconomic classes (75 percentile vs. 0-25 percentile: P = 0.009) and within southern states (vs. Northeast: P < 0.001).

Conclusion

Although there was an overall decrease in the trends of dialysis-associated complications requiring hospitalization among ESKD patients receiving hemodialysis, non-White patients have higher odds of complications compared to White patients. The findings in this study emphasize the need for more equitable care for hemodialysis patients.

Acute problems of hemodialysis access: Thrombosis, aneurysms, symptomatic high-flow fistulas, and complications related to central lines

Hemodynamic complications frequently affect vascular access and are important causes of morbidity and mortality. We present a review of acute complications affecting vascular accesses, focusing on classical and new treatments. Acute complications in hemodialysis vascular access are often underestimated and undertreated, and can present a challenge for both vascular surgeons and anesthesiologists. Accordingly, we considered different anesthesiologic approaches to both hemorrhagic and nonhemorrhagic patients. A strict collaboration among nephrologists, surgeons, and anesthesiologists can potentially improve prevention and management of acute complications and quality of life.

Association of Four Types of Vascular Access Including Arterial Superficialization with Mortality in Maintenance Hemodialysis Patients: A Nationwide Cohort Study in Japan

INTRODUCTION

Vascular access usage varies widely across countries. Previous studies have evaluated the association of clinical outcomes with the three types of vascular access, namely, arteriovenous fistula (AVF), arteriovenous graft (AVG), and tunneled and cuffed central venous catheter (TC-CVC). However, little is known regarding the association between arterial superficialization (AS) and the mortality of patients.

METHODS

A nationwide cohort study was conducted using data from the Japanese Society for Dialysis Therapy Renal Data Registry (2006-2007). We included patients aged ≥20 years undergoing hemodialysis with a dialysis vintage ≥6 months. The exposures of interest were the four types of vascular access: AVF, AVG, AS, and TC-CVC. Cox proportional hazard models were used to evaluate the associations of vascular access types with 1-year all-cause and cause-specific mortality.

RESULTS

A total of 183,490 maintenance hemodialysis patients were included: 90.7% with AVF, 6.9% with AVG, 2.0% with AS, and 0.4% with TC-CVC. During the 1-year follow-up period, 13,798 patients died. Compared to patients with AVF, those with AVG, AS, and TC-CVC had a significantly higher risk of all-cause mortality after adjustment for confounding factors: adjusted hazard ratios (95% confidence intervals) - 1.30 (1.20-1.41), 1.56 (1.39-1.76), and 2.15 (1.77-2.61), respectively. Similar results were obtained for infection-related and cardiovascular mortality.

CONCLUSION

This nationwide cohort study conducted in Japan suggested that AVF usage may have the lowest risk of all-cause mortality. The study also suggested that the usage of AS may be associated with better survival rates compared to those of TC-CVC in patients who are not suitable for AVF or AVG.

Staphylococcus aureus accumulation at the tip of hemodialysis catheters with or without tip side holes in catheter related bloodstream infection in a large animal

BACKGROUND

Eighty percent of hemodialysis patients start their dialysis with a tunneled hemodialysis catheter. Catheter related bacteremia is the second most common cause of death in these patients. Side holes near the tips of the tunneled cuffed central venous catheters are associated with accumulation of thrombus, which can lead to catheter dysfunction and, possibly, also to catheter-related infection. To assess the hypothesis that a catheter without side holes would be associated with less bacterial growth, this study compared the susceptibility of a side-hole-free catheter to accumulation of pathogenic bacteria at the catheter tip with that of two catheters which have side holes.

METHODS

Eight tunneled cuffed double-lumen central venous catheters were inserted into both jugular veins of four sheep; one side-hole-free and one control catheter with side holes at the tip in each animal. Staphylococcus aureus bacteria were then infused intravenously to cause bacteremia. Six hours later, the catheters were removed, the clots that accumulated in their tips were collected and cultured, and the bacterial colonies were counted after additional 12 h of incubation.

RESULTS

Bacteria grew on culture plates seeded with the clot homogenate obtained from the tips of all catheters. The colony counts from the catheters with side holes at the tip exceeded the colony counts of bacteria accumulated in the tips of the side-hole-free hemodialysis catheters by one or more orders of magnitude, with a difference of at least two orders of magnitude observed in three of the four intra-animal comparisons.

CONCLUSIONS

In paired intra-animal post-inoculation comparison made in this limited study, fewer colony forming units of pathogenic bacteria accumulated at the tip of the side-hole-free catheters than at the tips of the catheters which have side holes. This may translate to a decreased rate of catheter-related blood stream infections in the side-hole-free catheters.

Study protocol of a randomized controlled trial of fistula vs. graft arteriovenous vascular access in older adults with end-stage kidney disease on hemodialysis: the AV access trial

BACKGROUND

Treatment of end-stage kidney disease (ESKD) with hemodialysis requires surgical creation of an arteriovenous (AV) vascular access-fistula (AVF) or graft (AVG)-to avoid (or limit) the use of a central venous catheter (CVC). AVFs have long been considered the first-line vascular access option, with AVGs as second best. Recent studies have suggested that, in older adults, AVGs may be a better strategy than AVFs. Lacking evidence from well-powered randomized clinical trials, integration of these results into clinical decision making is challenging. The main objective of the AV Access Study is to compare, between the two types of AV access, clinical outcomes that are important to patients, physicians, and policy makers.

METHODS

This is a prospective, multicenter, randomized controlled trial in adults ≥ 60 years old receiving chronic hemodialysis via a CVC. Eligible participants must have co-existing cardiovascular disease, peripheral arterial disease, and/or diabetes mellitus; and vascular anatomy suitable for placement of either type of AV access. Participants are randomized, in a 1:1 ratio, to a strategy of AVG or AVF creation. An estimated 262 participants will be recruited across 7 healthcare systems, with average follow-up of 2 years. Questionnaires will be administered at baseline and semi-annually. The primary outcome is the rate of CVC-free days per 100 patient-days. The primary safety outcome is the cumulative incidence of vascular access (CVC or AV access)-related severe infections-defined as access infections that lead to hospitalization or death. Secondary outcomes include access-related healthcare costs and patients' experiences with vascular access care between the two treatment groups.

DISCUSSION

In the absence of studies using robust and unbiased research methodology to address vascular access care for hemodialysis patients, clinical decisions are limited to inferences from observational studies. The goal of the AV Access Study is to generate evidence to optimize vascular access care, based on objective, age-specific criteria, while incorporating goals of care and patient preference for vascular access type in clinical decision-making.

TRIAL REGISTRATION

This study is being conducted in accordance with the tenets of the Helsinki Declaration, and has been approved by the central institutional review board (IRB) of Wake Forest University Health Sciences (approval number: 00069593) and local IRB of each participating clinical center; and was registered on Nov 27, 2020, at ClinicalTrials.gov (NCT04646226).

Second Percutaneous Transluminal Angioplasty Versus Surgical Reconstruction for Hemodialysis Access Failure Within a Short Time Period

BACKGROUND

The purpose of this study was to compare patency and nonabandonment rates for second percutaneous transluminal angioplasty (PTA) and surgical reconstruction for the treatment of failing vascular access due to restenosis or reocclusion in a short time after initial PTA.

METHODS

Seventy two consecutive patients who underwent second treatment within 90 days after the initial PTA were evaluated retrospectively. The patency (time to corrective procedure) and access abandonment were compared among patients who underwent a second PTA (n = 35) and those who underwent surgical reconstruction (n = 37). Univariate and multivariate analyses were performed to determine independent predictors of patency and access abandonment at 1 year after the treatment.

RESULTS

At 1 year after the treatment, the patency rates were 35.1% and 11.4% (P = 0.02) and nonabandonment rates were 64.9% and 77.1% (P = 0.25) for surgical reconstruction and second PTA, respectively. The Kaplan-Meier survival analysis showed that the surgical reconstruction group had better patency probability (P = 0.02), but there was no difference in the nonabandonment probability between the groups (P = 0.29). Shorter time to retreatment was associated with good patency. The female gender was likely to be associated with access abandonment.

CONCLUSIONS

The access abandonment between the 2 procedures had no difference, although surgical reconstruction provided better patency than second PTA.

Long-term impact of early non-infectious complications at the initiation of peritoneal dialysis

BACKGROUND

Early non-infectious complications at initiation of peritoneal dialysis (PD) are a major burden with unknown long-term impacts on individuals.

METHODS

Prospective multicentre cohort study using univariable and multivariable Cox regression to identity mortality risk and PD discontinuation risk in those with and without non-infectious complications. All individuals commencing PD between 1 January 2014 and 31 December 2018, registered in the New Zealand Peritoneal Dialysis Registry (NZPDR) were followed up to 31 December 2020. Early non-infectious complications defined as functional, catheter-related, exit-site dialysate leak or anatomical leak complications occurring within 30 days of initiation of PD. Primary outcomes were patient survival and time on PD therapy. Secondary outcomes were peritonitis free survival, first PD catheter survival and catheter tunnel infection free survival.

RESULTS

Of 1596 individuals included in the study, 102 experienced an early non-infectious complication. Multivariable analysis demonstrated these complications were associated with higher risk of overall mortality (hazard ratio (HR) 1.71; 95% confidence interval (CI) 1.21-2.44), PD discontinuation (HR 1.84; 95% CI 1.41-2.41) and first catheter failure (HR 2.89; 95% CI 2.28-3.66). No difference was found for risk of development of first peritonitis episode or catheter tunnel infection. Mortality risk was associated with functional and exit-site dialysate leak complications and continued beyond 180 days. Risk of PD discontinuation and first catheter loss were associated with catheter and functional complications in the first 180 days.

CONCLUSION

Early non-infectious complications are associated with long-term mortality risk. Further research in risk factors and causes of early non-infectious complications are required.

Roles of PI3K/AKT/mTOR Axis in Arteriovenous Fistula

Renal failure is a worldwide disease with a continuously increasing prevalence and involving a rising need for long-term treatment, mainly by haemodialysis. Arteriovenous fistula (AVF) is the favourite type of vascular access for haemodialysis; however, the lasting success of this therapy depends on its maturation, which is directly influenced by many concomitant processes such as vein wall thickening or inflammation. Understanding the molecular mechanisms that drive AVF maturation and failure can highlight new or combinatorial drugs for more personalized therapy. In this review we analysed the relevance of critical enzymes such as PI3K, AKT and mTOR in processes such as wall thickening remodelling, immune system activation and inflammation reduction. We focused on these enzymes due to their involvement in the modulation of numerous cellular activities such as proliferation, differentiation and motility, and their impairment is related to many diseases such as cancer, metabolic syndrome and neurodegenerative disorders. In addition, these enzymes are highly druggable targets, with several inhibitors already being used in patient treatment for cancer and with encouraging results for AVF. Finally, we delineate how these enzymes may be targeted to control specific aspects of AVF in an effort to propose a more specialized therapy with fewer side effects.

Brachial artery transposition versus catheters as tertiary vascular access for maintenance hemodialysis: a single-center retrospective study

Some hemodialysis patients are not suitable for creation of an arteriovenous fistula (AVF) or arteriovenous graft (AVG). However, they can receive a tunneled cuffed central venous catheter (tcCVC), but this carries risks of infection and mortality. We aimed to evaluate the safety and effectiveness of brachial artery transposition (BAT) versus those of tcCVC. This retrospective study evaluated hemodialysis patients who underwent BAT or tcCVC placement because of severe heart failure, hand ischemia, central venous stenosis or occlusion, inadequate vessels for creating standard arteriovenous access, or limited life expectancy. The primary outcome was whole access circuit patency. Thirty-eight patients who underwent BAT and 25 who underwent tcCVC placement were included. One-year patency rates for the whole access circuit were 84.6% and 44.9% in the BAT and tcCVC groups, respectively. The BAT group was more likely to maintain patency (unadjusted hazard ratio: 0.17, 95% confidence interval: 0.05–0.60, p = 0.006). The two groups did not have significantly different overall survival (log-rank p = 0.146), although severe complications were less common in the BAT group (3% vs. 28%, p = 0.005). Relative to tcCVC placement, BAT is safe and effective with acceptable patency in hemodialysis patients not suitable for AVF or AVG creation.

Immuno-regenerative biomaterials for in situ cardiovascular tissue engineering - Do patient characteristics warrant precision engineering?

In situ tissue engineering using bioresorbable material implants - or scaffolds - that harness the patient's immune response while guiding neotissue formation at the site of implantation is emerging as a novel therapy to regenerate human tissues. For the cardiovascular system, the use of such implants, like blood vessels and heart valves, is gradually entering the stage of clinical translation. This opens up the question if and to what extent patient characteristics influence tissue outcomes, necessitating the precision engineering of scaffolds to guide patient-specific neo-tissue formation. Because of the current scarcity of human in vivo data, herein we review and evaluate in vitro and preclinical investigations to predict the potential role of patient-specific parameters like sex, age, ethnicity, hemodynamics, and a multifactorial disease profile, with special emphasis on their contribution to the inflammation-driven processes of in situ tissue engineering. We conclude that patient-specific conditions have a strong impact on key aspects of in situ cardiovascular tissue engineering, including inflammation, hemodynamic conditions, scaffold resorption, and tissue remodeling capacity, suggesting that a tailored approach may be required to engineer immuno-regenerative biomaterials for safe and predictive clinical applicability.

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.

Association Between Attempted Arteriovenous Fistula Creation and Mortality in People Starting Hemodialysis via a Catheter: A Multicenter, Retrospective Cohort Study

Background:

In North America, most people start hemodialysis via a central venous catheter (“catheter”). These patients are counseled to undergo arteriovenous fistula (“fistula”) creation within weeks of starting hemodialysis because fistulas are associated with improved survival.

Objectives:

To determine whether attempting to create a fistula in patients who start hemodialysis via a catheter is associated with improved mortality. We also sought to determine whether differences in baseline patient characteristics, vascular procedures for access-related complications, or days in hospital may confound or mediate the relationship between attempted fistula creation and mortality.

Design:

Multicenter, retrospective cohort study.

Setting:

Six dialysis programs located in Ontario, Alberta, and Manitoba.

Patients:

Patients aged ≥18 years who initiated hemodialysis via a catheter between January 1, 2004, and May 31, 2012, who had not had a previous attempt at fistula creation. We excluded those who had a life expectancy less than 1 year, who transitioned to peritoneal dialysis within 6 months of starting dialysis, and people who started hemodialysis via a graft.

Measurements:

Attempted fistula creation, all-cause mortality, patient characteristics and comorbidities, vascular procedures for access-related complications, and days spent in hospital.

Methods:

We used survival methods, including marginal structural models, to account for immortal time bias and time-varying confounding.

Results:

In total, 1832 patients initiated hemodialysis via a catheter during the study period and met inclusion criteria. Of these patients, 565 (31%) underwent an attempt at fistula creation following hemodialysis start. As compared to those who did not receive a fistula attempt, these people were younger, had fewer comorbidities, and were more likely to have started dialysis as an outpatient and to have received pre-dialysis care. In a marginal structural model controlling for baseline characteristics and comorbidities, attempted fistula creation was associated with a significantly lower mortality (hazard ratio [HR] = 0.53; 95% confidence interval [CI] = 0.43-0.66). This effect did not appear to be confounded or mediated by differences in the number of days spent in hospital or vascular procedures for access-related complications. It also remained similar in analyses restricted to patients who survived at least 6 months (HR = 0.60; 95% CI = 0.47-0.77) and to patients who started hemodialysis as an outpatient (HR = 0.48; 95% CI = 0.33-0.68).

Limitations:

There is likely residual confounding and treatment selection bias.

Conclusions:

In this multicenter cohort study, attempting fistula creation in people who started hemodialysis via a catheter was associated with significantly reduced mortality. This reduction in mortality could not be explained by differences in patient characteristics or comorbidities, days spent in hospital, or vascular procedures for access-related complications. Residual confounding or selection bias may explain the observed benefits of fistulas for hemodialysis access.

Trial Registration:

Not applicable (cohort study).

Cannulation technique and complications in arteriovenous fistulas: a Swedish Renal Registry-based cohort study

BACKGROUND

The four cannulation techniques, rope ladder (RL), area puncture (AP), buttonhole with blunt needles (BHb), and buttonhole with sharp needles (BHs), affects the arteriovenous fistula (AVF) in different ways. The aim of this study was to describe the relationship between the different cannulation techniques and the occurrence of AVF complications.

METHODS

The study was performed as a national registry-based cohort study using data from the Swedish Renal Registry (SRR). Data were collected from January 2014 to October 2019. Seventy of Sweden's dialysis units participate in the registry. We analyzed a total of 1328 AVFs in this study. The risk of complications was compared between the four different cannulation techniques. The risk of AVF complications was measured by the incidence and incidence rate ratio (IRR). We compared the IRRs of complications between different cannulation techniques.

RESULTS

BHs is the most common cannulation technique in Sweden. It has been used in 55% of the AVFs at some point during their functional patency. BHb (29%), RL (13%), and AP (3%) has been used less. BHb had the lowest risk of complications compared to the other techniques, and a significantly lower risk of stenosis, infiltration, cannulation difficulties, compared to RL and BHs. Cannulation difficulties were significantly more common using AP compared to BHs, and BHb. Infections were not significantly increased using the buttonhole technique.

CONCLUSIONS

BHb had the lowest risk of complications. Infections were not significantly increased using the buttonhole technique. Dialysis units with a low infection rate may continue to use the buttonhole technique, as the risk of complications is lower.

Mortality of hemodialysis patients is associated with their clinical situation at the start of treatment

INTRODUCTION

Previous reports have shown very high mortality among hemodialyisis patients. Our goal was to analyze the mortality of patients in the Renal Registry of Patients who remained exclusively on hemodialysis treatment.

METHODS

The cohort of patients who started treatment in the community of Castilla-La Mancha between 2010 and 2012 and remained on hemodialysis treatment was analysed until the end of 2017. Age, sex, primary kidney disease, vascular access, hemoglobin, Charlson index and serum albumin were included.

RESULTS

Mortality rate was 63,4% after 5 years and 76% at the end of the study, with no difference between males and females, and was linked to an older age, urgent onset or in those with acute deterioration of chronic kidney disease, the use of catheters or albumin less than 3.5 g/dl.

CONCLUSIONS

Mortality in patients who remain on hemodialysis is very high and is associated with non-modifiable factors such as age but also others that we can prevent or treat such as type of vascular access or nutrition status at the beginning of treatment.

Is home hemodialysis a practical option for older people?

An increasing demand for in-center dialysis services has been largely driven by a rapid growth of the older population progressing to end-stage kidney disease. Since the onset of the COVID-19 pandemic, efforts to encourage home-based dialysis options have increased due to risks of infective transmission for patients receiving hemodialysis in center-based units. There are various practical and clinical advantages for patients receiving hemodialysis at home. However, the lack of caregiver support, cognitive and physical impairment, challenges of vascular access, and preparation and training for home hemodialysis (HHD) initiation may present as barriers to successful implementation of HHD in the older dialysis population. Assessment of an older patient's frailty status may help clinicians guide patients when making decisions about HHD. The development of an assisted HHD care delivery model and advancement of telehealth and technology in provision of HHD care may increase accessibility of HHD services for older patients. This review examines these factors and explores current unmet needs and barriers to increasing access, inclusion, and opportunities of HHD for the older dialysis population.

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.

New Devices and Technologies for Hemodialysis Vascular Access: A Review

In the United States, hemodialysis remains the most common treatment modality for kidney failure, chosen by almost 90% of incident patients. A functioning vascular access is key to providing adequate hemodialysis therapy. Recently, major innovations in devices and technology for hemodialysis vascular access care have rapidly changed the landscape. Novel endovascular devices for creation of arteriovenous fistulas may offer a solution to the barriers encountered in initiating maintenance hemodialysis with a permanent vascular access rather than a central venous catheter (CVC). Furthermore, in the prevalent hemodialysis population, the minimally invasive endovascular arteriovenous fistula procedure should help improve long wait times for vascular access creation, which remains a major barrier to reducing CVC dependence. Bioengineered grafts are being developed and may offer another option to polytetrafluoroethylene grafts. Early studies with these biocompatible grafts are promising, as additional studies continue to evaluate their clinical outcomes in comparison to cryopreserved or synthetic options. Prolonging the vascular access patency with appropriate use of devices such as drug-coated balloons and stent grafts may complement the novel techniques of creating arteriovenous access. Finally, innovative solutions to treat stenosed and occluded thoracic central veins can provide an approach to creating a vascular access and allow patients with exhausted vasculature to remain on hemodialysis. The robust developments in hemodialysis vascular access are likely to change practice patterns in the near future.

A call to optimize haemodialysis vascular access care in healthcare disrupted by COVID-19 pandemic

The COVID-19 pandemic has resulted in major disruption to the delivery of both routine and urgent healthcare needs in many institutions across the globe. Vascular access (VA) for haemodalysis (HD) is considered the patient's lifeline and its maintenance is essential for the continuation of a life saving treatment. Prior to the COVID-19 pandemic, the provision of VA for dialysis was already constrained. Throughout the pandemic, inevitably, many patients with chronic kidney disease (CKD) have not received timely intervention for VA care. This could have a detrimental impact on dialysis patient outcomes in the near future and needs to be addressed urgently. Many societies have issued prioritisation to allow rationing based on clinical risk, mainly according to estimated urgency and need for treatment. The recommendations recently proposed by the European and American Vascular Societies in the COVID-19 pandemic era regarding the triage of various vascular operations into urgent, emergent and elective are debatable. VA creation and interventions maintain the lifeline of complex HD patients, and the indication for surgery and other interventions warrants patient-specific clinical judgement and pathways. Keeping the use of central venous catheters at a minimum, with the goal of creating the right access, in the right patient, at the right time, and for the right reasons, is mandatory. These strategies may require local modifications. Risk assessments may need specific "renal pathways" to be developed rather than applying standard surgical risk stratification. In conclusion, in order to recover from the second wave of COVID-19 and prepare for further phases, the provision of the best dialysis access, including peritoneal dialysis, will require working closely with the multidisciplinary team involved in the assessment, creation, cannulation, surveillance, maintenance, and salvage of definitive access.

Contemporary outcomes of a "snuffbox first" hemodialysis access approach in the United States

OBJECTIVE

The Society for Vascular Surgery guidelines for permanent hemodialysis (HD) access creation recommend prioritizing the most distal possible autogenous access to minimize complications and preserve more proximal options. The "snuffbox" arteriovenous fistula (AVF) is the most distal radial artery-cephalic vein AVF. Despite the theoretical benefits of the snuffbox approach, recent trends have been toward upper arm access. Our study sought to investigate the feasibility of a snuffbox-first strategy for HD access in all anatomically appropriate candidates.

METHODS

From January 2016 to August 2019, all patients with end-stage renal disease (ESRD) or pre-ESRD under consideration for HD access were evaluated for a snuffbox-first approach by a team of vascular surgeons and nephrologists at a single, urban academic medical center in the United States. Data were collected prospectively and supplemented by medical record review. A survival analysis was performed to evaluate primary unassisted and secondary patency and clinical and functional maturation. Patients were censored if they had received a kidney transplant or had died. Cox proportional hazards regression was used to determine the risk factors for prolonged clinical maturation and functional maturation.

RESULTS

A total of 55 snuffbox AVFs were created. The median patient age was 60 years (interquartile range [IQR], 52-70 years), and 52.7% of the patients were men. The median follow-up was 369 days (IQR, 166-509 days). The median survival for primary unassisted patency was 90 days (95% confidence interval [CI], 79-111). Secondary patency at 1 year was 92.3% (95% CI, 85.3%-99.9%). The clinical maturation rate at 1 year was 83.7% (n = 55; 95% CI, 66.8%-91.9%), and the functional maturation rate at 1 year was 85.6% (n = 40; 95% CI, 63.3%-94.4%). Of the patients who were pre-ESRD at AVF creation and had initiated HD during the study period, 87.5% had successfully received incident HD with their snuffbox AVF. Twenty-four patients were receiving HD via a catheter at snuffbox creation. Of those patients, the functional maturation rate at 1 year was 82.5% (95% CI, 44.8%-94.4%). The patients had undergone a median of two interventions (IQR, zero to seven interventions) in the first year. Of these, 46.9% were percutaneous angioplasty and 31.2% were side-branch ligation. Diabetes was associated with slower AVF clinical maturation (multivariate hazard ratio, 0.35; 95% CI, 0.15-0.82; P = .016). A larger artery diameter was associated with earlier AVF clinical maturation (multivariate hazard ratio, 6.64; 95% CI, 2.11-20.9).

CONCLUSIONS

A snuffbox-first approach to HD access is a viable option for distal access creation in a cohort of patients requiring HD in the United States. Subsequent ancillary interventions to facilitate access maturation were required for most patients.

Mortality of hemodialysis patients is associated with their clinical situation at the start of treatment

INTRODUCTION

Previous reports have shown very high mortality among hemodialyisis patients. Our goal was to analyze the mortality of patients in the Renal Registry of Patients who remained exclusively on hemodialysis treatment.

METHODS

The cohort of patients who started treatment in the community of Castilla-La Mancha between 2010 and 2012 and remained on hemodialysis treatment was analysed until the end of 2017. Age, sex, primary kidney disease, vascular access, hemoglobin, Charlson index and serum albumin were included.

RESULTS

Mortality rate was 63.4% after 5 years and 76% at the end of the study, with no difference between males and females, and was linked to an older age, urgent onset or in those with acute deterioration of chronic kidney disease, the use of catheters or albumin less than 3.5g/dl.

CONCLUSIONS

Mortality in patients who remain on hemodialysis is very high and is associated with non-modifiable factors such as age but also others that we can prevent or treat such as type of vascular access or nutrition status at the beginning of treatment.

Demographics and clinical features of elderly patients undergoing regular dialysis in Brazil

An increasing number of elderly people in renal support is expected in the coming years. The objective of this study was to report the clinical and socio-demographic data of end-stage renal disease (ESRD) adult patients undergoing regular dialysis treatment comparing elderly (≥65 years old) and non-elderly subjects using data from the Brazilian Dialysis Registry database. The regional distribution of the sample was Southeast (48.8%), South (33.7), Northeast (13.1%), Midwest (5.1%), and North (0.1%). A total of 18,030 patients were included in the analysis with elderly patients accounting for 29.5% of the sample. The elderly patients were predominantly male, white, retired, and literate. Elderly ESRD patients had a slightly higher frequency of undernourishment and a lower frequency of obesity than the non-elderly adults. A higher frequency of elderly patients were from the South and Southeast regions. The dialysis treatment of patients from both groups was predominantly funded by the public system, but the percent of non-public funding was higher for the elderly group. The most used initial access in the elderly was the central venous catheter and hemodialysis was the main modality at the beginning of treatment (93.2%), as well as during maintenance therapy (91.8%). Advanced age was associated with greater use of central venous catheter in the first dialysis session. The survival of the elderly on dialysis was lower than that of the non-elderly early in the course of dialysis and this difference increased over time. This is yet the largest national epidemiological study of elderly people on chronic dialysis.

Long-Term Outcomes of the Flixene Vascular Graft Used for Haemodialysis

Introduction

The Flixene™ vascular graft (Maquet-Atrium Medical, Hudson, NH) has emerged as a new generation synthetic graft, which allows for early needling for haemodialysis. Most studies have shown satisfactory early results. The aim of this study is to report on long-term outcomes of the Flixene graft over eight years in a cohort of patients.

Methods

From February 2011 to September 2019, 61 patients had 64 arteriovenous graft fistulas (AVGs) by using the Flixene grafts. The median patient age was 67 years; the male to female ratio was 30:31. Diabetes was the reason for the majority of kidney failures (57%). The configuration of the grafts used was mostly upper arm straight AVG. The primary patency rate, secondary patency rate, and surgical complications were assessed.

Results

In a median follow-up of three years (interquartile range (IQR): 2 - 6), 36 of the AVGs required a fistulogram. Venous side stenosis was the most common cause of high venous pressure or AVG occlusion in 97%. The one-year primary patency rate was 30%. The secondary patency rate was 94.8%, 83.7%, and 77.7% at one, three, and five years, respectively. The longest functional AVG was observed for up to seven years.

Conclusions

This study has shown satisfactory long-term results of the Flixene graft used for hemodialysis. The Flixene graft could be needled within 72 hours without increased complications, which allows the creation of an AVG under an emergency setting to avoid the placement of a central venous catheter (CVC). This strategy should be advocated in future clinical practice.

Epidemiology of end-stage kidney disease

End-stage kidney disease (ESKD) is a common and morbid disease that affects patients' quality and length of life, representing a large portion of health care expenditure in the United States. These patients commonly have associated diabetes and cardiovascular disease, with high rates of cardiovascular-related death. Management of ESKD requires renal replacement therapy via dialysis or transplantation. While transplantation provides the greatest improvement in survival and quality of life, the vast majority of patients are treated initially with hemodialysis. However, outcomes differ significantly among patient populations. Barriers in access to care have particularly affected at-risk populations, such as Black and Hispanic patients. These patients receive less pre-ESKD nephrology care, are less likely to initiate dialysis with a fistula, and wait longer for transplants-even in pediatric populations. Priorities for ESKD care moving into the future include increasing access to nephrology care in underprivileged populations, providing patient-centered care based on each patient's "life plan," and focusing on team-based approaches to ESKD care. This review explores ESKD from the perspective of epidemiology, costs, vascular access, patient-reported outcomes, racial disparities, and the impact of the COVID-19 crisis.

Age is just a number: Is frailty being ignored in vascular access planning for dialysis?

Current international guidelines advocate fistula creation as first choice for vascular access in haemodialysis patients, however, there have been suggestions that in certain groups of patients, in particular the elderly, a more tailored approach is needed. The prevalence of more senior individuals receiving renal replacement therapy has increased in recent years and therefore including patient age in decision making regarding choice of vascular access for dialysis has gained more relevance. However, it seems that age is being used as a surrogate for overall clinical condition and it can be proposed that frailty may be a better basis to considering when advising and counselling patients with regard to vascular access for dialysis. Frailty is a clinical condition in which the person is in a vulnerable state with reduced functional capacity and has a higher risk of adverse health outcomes when exposed to stress inducing events. Prevalence of frailty increases with age and has been associated with an increased risk of mortality, hospitalisation, disability and falls. Chronic kidney disease is associated with premature ageing and therefore patients with kidney disease are prone to be frailer irrespective of age and the risk increases further with declining kidney function. Limited data exists on the relationship between frailty and vascular access, but it appears that frailty may have an association with poorer outcomes from vascular access. However, further research is warranted. Due to complexity in decision making in dialysis access, frailty assessment could be a key element in providing patient-centred approach in planning and maintaining vascular access for dialysis.

Epidemiology of bloodstream infections in a Scottish haemodialysis population with focus on vascular access method

BACKGROUND

Infection is the second highest cause of mortality in end-stage renal disease, with a significant proportion relating to haemodialysis (HD) vascular access-related infection (VARI).

AIM

To report the rate and antimicrobial resistance (AMR) of all-source bloodstream infections (BSIs) by vascular access type in a Scottish HD cohort.

METHODS

Retrospective analysis was undertaken of data on adult patients attending seven HD units during 2017. Total HD days for each vascular access type were calculated. BSIs were analysed with rates expressed per 1000 HD days. AMR was verified using health board microbiology databases.

FINDINGS

Excluding contaminant organisms, there was an overall BSI rate of 0.57 per 1000 HD days. The highest all-source and vascular access-related infection (VARI) BSI rates per 1000 HD days were in the non-tunnelled central venous catheter (CVC) group (3.11 and 2.07 respectively), followed by tunnelled CVC (1.10 and 0.67), arteriovenous graft (0.51 and 0.31), and finally arteriovenous fistula (0.29 and 0.02). The non-VARI BSI rates were lowest in the arteriovenous graft group. Staphylococci comprised the majority of events, with Staphylococcus aureus implicated in 29%. Gram-negative BSIs were prevalent, particularly in CVC groups, and associated with higher mortality. Multidrug-resistant (MDR) S. aureus and carbapenem resistance were relatively low. MDR Gram-negatives were high compared with the Scottish population.

CONCLUSION

Arteriovenous fistula access is confirmed as having lowest all-source and VARI BSI rates, and arteriovenous graft access the lowest non-VARI BSI rates. Staphylococci remain the prevailing genus; however, the contributions of Gram-negative BSIs, the higher mortality, and proportion of MDR organisms in this group are notable.

Inferiority of arteriovenous grafts, in comparison to autogenous fistulas, is underestimated by standard survival measures alone

BACKGROUND

It has been argued that a prosthetic arteriovenous graft (AVG) is a reasonable alternative to an arteriovenous fistula (AVF) for dialysis. We aimed to compare the patency rates and requirements for the intervention of newly formed AVF and AVG.

METHODS

A retrospective analysis was undertaken of AVF and AVG formed between 1 January 2013 and 31 December 2015 at two tertiary referral centres and followed up until 31 December 2017. Outcome measures included successful use for dialysis, patency rates and the number of interventions required to maintain dialysis access per patient-year (PPY).

RESULTS

Four hundred and seventy AVF and 92 AVG were constructed. Of 470 AVF, 324 (68.9%) were used compared to 80 of 92 (87%) AVG. One year assisted primary patency of AVF was 75% (confidence interval 71-79%) compared to 47% (confidence interval 36-57%) for AVG. Secondary patency rates for AVF at 1, 2 and 3 years were 77%, 71% and 69%, respectively. At the same time points, secondary patency rates for AVG were 77%, 60% and 46%, respectively (log rank P = 0.034). AVG required 2.4 times the number of interventions PPY than AVF. Surgical thrombectomy of AVG was at a rate of 0.49 PPY compared with 0.042 PPY for AVF.

CONCLUSION

AVG have a substantially higher rate of thrombosis than AVF, evident from early in the life of the graft. AVF demonstrate superior patency rates to AVG throughout the life of the access, with far fewer interventions PPY than grafts.

Elevated Circulating Cell-Free DNA in Hemodialysis-Treated Patients Is Associated with Increased Mortality

BACKGROUND

Predicting the mortality risk of patients un-dergoing hemodialysis (HD) is challenging. Cell-free DNA (cfDNA) is released into circulation from dying cells, and its elevation is predictive of unfavorable outcome. In a pilot study, we found post-HD cfDNA level to be a predictor of all-cause mortality. Thus, the aim of this study was to confirm the prognostic power of cfDNA in a larger prospective cohort study conducted at 2 medical centers.

METHODS

CfDNA levels were measured by a rapid fluorometric assay on sera obtained before and after 1 HD session. One hundred fifty-three patients were followed up to 46 months for mortality during which time 47 patients died. We compared the predictive value of cfDNA to age, comorbidities, and standard blood tests.

RESULTS

Examining standard blood tests, only post-HD cfDNA levels were elevated in the non-survivor group compared to survivors (959 vs. 803 ng/mL, p = 0.04). Pre- and post-HD cfDNA levels correlated with age and diabetes. Patients with elevated cfDNA (>850 ng/mL) showed lower survival than those with normal levels. A Cox proportional hazard regression model demonstrated a significant hazard ratio of 1.92 for post-HD cfDNA levels. Logistic regression models showed that post-HD cfDNA was a significant predictor of mortality at 1-3 years with odd ratios of 4.61, 4.36, and 6.22, respectively.

CONCLUSIONS

Post-HD cfDNA level was superior to standard blood tests and could serve as a biomarker to assist in decision-making for HD-treated patients.

Practice patterns of dialysis access and outcomes in patients wait-listed early for kidney transplantation

BACKGROUND

Early kidney transplantation (KT) is the best option for patients with end-stage kidney disease, but little is known about dialysis access strategy in this context. We studied practice patterns of dialysis access and how they relate with outcomes in adults wait-listed early for KT according to the intended donor source.

METHODS

This study from the REIN registry (2002-2014) included 9331 incident dialysis patients (age 18-69) wait-listed for KT before or by 6 months after starting dialysis: 8342 candidates for deceased-donor KT and 989 for living-donor KT. Subdistribution hazard ratios (SHR) of KT and death associated with hemodialysis by catheter or peritoneal dialysis compared with arteriovenous (AV) access were estimated with Fine and Gray models.

RESULTS

Living-donor candidates used pretransplant peritoneal dialysis at rates similar to deceased-donor KT candidates, but had significantly more frequent catheter than AV access for hemodialysis (adjusted OR 1.25; 95%CI 1.09-1.43). Over a median follow-up of 43 (IQR: 23-67) months, 6063 patients received transplants and 305 died before KT. Median duration of pretransplant dialysis was 15 (7-27) months for deceased-donor recipients and 9 (5-15) for living-donor recipients. Catheter use in deceased-donor candidates was associated with a lower SHR for KT (0.88, 95%CI 0.82-0.94) and a higher SHR for death (1.53, 95%CI 1.14-2.04). Only five deaths occurred in living-donor candidates, three of them with catheter use.

CONCLUSIONS

Pretransplant dialysis duration may be quite long even when planned with a living donor. Advantages from protecting these patients from AV fistula creation must be carefully evaluated against catheter-related risks.

Challenges and novel therapies for vascular access in haemodialysis

Advances in standards of care have extended the life expectancy of patients with kidney failure. However, options for chronic vascular access for haemodialysis - an essential part of kidney replacement therapy - have remained unchanged for decades. The high morbidity and mortality associated with current vascular access complications highlights an unmet clinical need for novel techniques in vascular access and is driving innovation in vascular access care. The development of devices, biological approaches and novel access techniques has led to new approaches to controlling fistula geometry and manipulating the underlying cellular and molecular pathways of the vascular endothelium, and influencing fistula maturation and formation through the use of external mechanical methods. Innovations in arteriovenous graft materials range from small modifications to the graft lumen to the creation of completely novel bioengineered grafts. Steps have even been taken to create new devices for the treatment of patients with central vein stenosis. However, these emerging therapies face difficult hurdles, and truly creative approaches to vascular access need resources that include well-designed clinical trials, frequent interaction with regulators, interventionalist education and sufficient funding. In addition, the heterogeneity of patients with kidney failure suggests it is unlikely that a 'one-size-fits-all' approach for effective vascular access will be feasible in the current environment.

Determinants of venous catheter hemodialysis onset and subsequent switch to arteriovenous fistula: An epidemiological study in Lazio region

BACKGROUND

The factors associated with the inability to start hemodialysis with an arteriovenous fistula (AVF) in chronic kidney disease patients are not fully understood.

AIM

Evaluating factors associated with type of vascular access at the first chronic hemodialysis and at 1 year after it.

METHODS

The study cohort includes patients registered in the Regional Dialysis and Transplant Registry of Lazio undergoing first hemodialysis between 2008 and 2015. Logistic regression models were used to evaluate the association between socio-demographic, clinical and care/organizational factors, and vascular access at first hemodialysis. Cox regression models were used to assess the odds of switching to AVF during the first year of hemodialysis among patients starting dialysis with central venous catheter (CVC).

RESULTS

In the cohort of 6208 incident hemodialysis patients, 52.7% had an AVF and 47.3% had a CVC. Among the 2939 incident patients with CVC, 27.4% switched to FAV after 1 year. A higher probability of starting dialysis with AVF was observed among males (OR = 1.83; 95% CI 1.63-2.06), while a lower probability was observed among patients aged >85 years (OR 0.64; IC 95% 0.51-0.80). Patients with early referral to a nephrologist had a triple probability of start dialysis with AVF. We observed a higher odds of switch to AVF among males (HR = 1.62; 95% CI 1.40-1.89) and a lower odds among patients over 65 years.

CONCLUSION

The observed high rate of AVF at the start of hemodialysis and of the switch from CVC to AVF in the first year, although declining since 2008, is a positive outcome. However, over one-third of patients maintain the CVC as vascular access for the first year because of unmodifiable factors, such as gender, age, comorbidity. The present study suggests that logistics/management and assistance/welfare problems may contribute to the delay or lack of AVF placement in incident hemodialysis patients or within the first year of dialysis.

Different risk factors are associated with vascular access patency after construction and percutaneous transluminal angioplasty in patients starting hemodialysis

BACKGROUND

The objective of this multicenter, prospective observational study was to determine the factors related to patency rates after construction of vascular access (VA) and the first percutaneous transluminal angioplasty (PTA).

METHODS

The 24-month primary and secondary patency rates after construction of a radiocephalic arteriovenous fistula (RC-AVF) and arteriovenous graft (AVG) were evaluated using the Kaplan-Meier method and log-rank test. The 12-month post-PTA patency rate was also investigated. A Cox proportional hazard model was used to identify clinical parameters associated with the primary patency rate and the post-PTA patency rate.

RESULTS

A total of 611 patients were enrolled in the study. The primary patency rate after VA construction was lower in hemodialysis (HD) patients with an AVG than in those with an AVF. Aging (hazard ratio [HR], 1.02 per 1 year; p < 0.001), female sex (HR, 1.41; p = 0.03), diabetes mellitus (HR, 1.37; p = 0.03), low serum albumin (HR, 0.76 per 1-g/dL decrease; p = 0.02), and use of an erythropoietin-stimulating agent (HR, 1.62; p = 0.02) were risk factors for VA problems. The post-PTA patency rate was associated with aging (HR, 1.02; p < 0.001), diabetes mellitus (HR, 1.49; p = 0.02), polycystic kidney disease (HR, 2.14; p = 0.01), temporary catheter use for initiation of HD (HR, 1.60; p = 0.02), and period from VA construction to use (HR, 0.99; p = 0.04).

CONCLUSION

Although a poor patency rate is commonly associated with advanced age and diabetes, different risk factors affect patency between VA construction and the first PTA.

Sex differences in the vascular access of hemodialysis patients: a cohort study

Background

We describe differences for probability of receiving a fistula attempt, achieving fistula use, remaining catheter-free and the rate of access-related procedures as a function of sex.

Methods

Prospectively collected vascular access data on incident dialysis patients from five Canadian programs using the Dialysis Measurement Analysis and Reporting System to determine differences in fistula-related outcomes between women and men. The probability of receiving a fistula attempt and the probability of fistula use were determined using binary logistic regression. Catheter and fistula procedure rates were described using Poisson regression. We studied time to fistula attempt and time to fistula use, accounting for competing risks.

Results

We included 1446 (61%) men and 929 (39%) women. Men had a lower body mass index (P < 0.001) and were more likely to have coronary artery disease (P < 0.001) and peripheral vascular disease (p < 0.001). A total of 688 (48%) men and 403 (43%) women received a fistula attempt. Women were less likely to receive a fistula attempt by 6 months {odds ratio [OR] 0.64 [95% confidence interval (CI) 0.52-0.79]} and to achieve catheter-free use of their fistula by 1 year [OR 0.38 (95% CI 0.27-0.53)]. At an average of 2.30 access procedures per person-year, there is no difference between women and men [incidence rate ratio (IRR) 0.97 (95% CI 0.87-1.07)]. Restricting to those with a fistula attempt, women received more procedures [IRR 1.16 (95% CI 1.04-1.30)] attributed to increased catheter procedures [IRR 1.50 (95% CI 1.27-1.78)]. There was no difference in fistula procedures [IRR women versus men 0.96 (95% CI 0.85-1.07)].

Conclusion

Compared with men, fewer women undergo a fistula attempt. This disparity increases after adjusting for comorbidities. Women have the same number of fistula procedures as men but are less likely to successfully use their fistula.

Infected Hemodialysis Arteriovenous Fistula with Distant Explosive Pleuritis: A Rare Phenomenon

Patient: Male, 36-year-old

Final Diagnosis: Explosive pleuritis

Symptoms: Abdominal pain

Medication:—

Clinical Procedure: —

Specialty: Critical Care Medicine • Infectious Diseases • General and Internal Medicine • Nephrology • Pulmonology

Efficacy and safety associated with the use of the Surfacer® Inside-Out® Access Catheter System: Results from a prospective, multicenter Food and Drug Administration-approved Investigational Device Exemption study

Purpose:

Thoracic central venous obstruction is commonly associated with the use of central venous catheters. The Surfacer System to Facilitate Access in Venous Occlusions Study was an Food and Drug Administration–approved US Investigational Device Exemption study designed to evaluate the performance and safety of the Surfacer System when used to facilitate central venous access in patients with thoracic central venous obstruction.

Methods:

Thirty patients were enrolled in this prospective, multicenter, single-arm study between December 2017 and May 2019. Device performance and adverse events were collected peri-procedurally and at discharge. Enrollment included 15 female and 15 male subjects with a mean age of 55.5 ± 12.9 (range: 30–79) years. Twenty-eight patients (93.3%) required central venous access for hemodialysis access. Locations of thoracic central venous obstruction were graded from 1 to 4 based on severity and extension of venous occlusions. Seven patients (23.3%) had type 1, 6 (20.0%) type 2, 16 (53.3%) type 3, and 1 (3.3%) type 4 obstruction.

Results:

Successful central venous catheter placement was achieved in 27 of 30 patients (90.0%). The procedure was discontinued in three (10.0%) due to tortuous anatomy discovered intraprocedurally. All 27 patients with successful CVC placement achieved adequate catheter patency and tip positioning with a mean overall procedural time and time to achieve central venous access with the Surfacer System being 44.1 ± 30.6 and 19.1 ± 25.1 min, respectively. There were no device-related adverse events or catheter malposition.

Conclusion:

The results of the SAVEUS Study confirm the safety and efficacy of the Surfacer System and the Inside-Out procedure when used for the placement of right-sided central venous access in patients with thoracic central venous obstruction.