A randomized controlled trial and cost-effectiveness analysis of early cannulation arteriovenous grafts versus tunneled central venous catheters in patients requiring urgent vascular access for hemodialysis

Cost-effectiveness analysis of autogenous arteriovenous fistula, arteriovenous graft, and tunneled-cuffed catheter for hemodialysis in patients with end-stage kidney disease in Southern China

OBJECTIVES

To evaluate the cost-effectiveness of three permanent vascular accesses for maintenance hemodialysis patients from a hospital perspective throughout 5 years, which is the average life expectancy of patients with end-stage kidney disease.

SUBJECTS AND METHODS

We conducted a EuroQol(EQ-5D) questionnaire survey between January 2021 and March 2021 with 250 patients to estimate the health utility of various states in patients under different hemodialysis vascular access. We designed a Markov model and conducted a cost-effectiveness analysis to compare the cost-effectiveness of three hemodialysis vascular access in Guangzhou throughout 5 years.

RESULTS

The mean costs were US$44,481 with tunneled-cuffed catheter (TCC), and US$68,952 and US$59,247 with arteriovenous graft (AVG) and autogenous arteriovenous fistula (AVF), respectively. The mean quality-adjusted life-years (QALYs) was 1.41 with TCC, and 2.37 and 2.73 with AVG and AVF, respectively. AVG had an incremental cost-effectiveness ratio (ICER) of US$25,491 per QALY over TCC; AVF had an ICER of -US$26,958 per QALY over AVG. At a willingness to pay below US$10,633.8 per QALY, TCC is likely the most cost-effective vascular access. At any willingness to pay between US$10,633.8 and US$30,901.4 per QALY, AVF is likely the most cost-effective vascular access.

CONCLUSION

These findings illustrate the value of AVF given its relative cost-effectiveness to other hemodialysis modalities. Although AVG costs much more than TCC for slightly higher QALYs than TCC, AVG still has a greater advantage over TCC for patients with longer life expectancy due to its lower probability of death.

Arteriovenous Access for Hemodialysis: A Review

Importance

Hemodialysis requires reliable vascular access to the patient's blood circulation, such as an arteriovenous access in the form of an autogenous arteriovenous fistula or nonautogenous arteriovenous graft. This Review addresses key issues associated with the construction and maintenance of hemodialysis arteriovenous access.

Observations

All patients with kidney failure should have an individualized strategy (known as Patient Life-Plan, Access Needs, or PLAN) for kidney replacement therapy and dialysis access, including contingency plans for access failure. Patients should be referred for hemodialysis access when their estimated glomerular filtration rate progressively decreases to 15 to 20 mL/min, or when their peritoneal dialysis, kidney transplant, or current vascular access is failing. Patients with chronic kidney disease should limit or avoid vascular procedures that may complicate future arteriovenous access, such as antecubital venipuncture or peripheral insertion of central catheters. Autogenous arteriovenous fistulas require 3 to 6 months to mature, whereas standard arteriovenous grafts can be used 2 to 4 weeks after being established, and "early-cannulation" grafts can be used within 24 to 72 hours of creation. The prime pathologic lesion of flow-related complications of arteriovenous access is intimal hyperplasia within the arteriovenous access that can lead to stenosis, maturation failure (33%-62% at 6 months), or poor patency (60%-63% at 2 years) and suboptimal dialysis. Nonflow complications such as access-related hand ischemia ("steal syndrome"; 1%-8% of patients) and arteriovenous access infection require timely identification and treatment. An arteriovenous access at high risk of hemorrhaging is a surgical emergency.

Conclusions and Relevance

The selection, creation, and maintenance of arteriovenous access for hemodialysis vascular access is critical for patients with kidney failure. Generalist clinicians play an important role in protecting current and future arteriovenous access; identifying arteriovenous access complications such as infection, steal syndrome, and high-output cardiac failure; and making timely referrals to facilitate arteriovenous access creation and treatment of arteriovenous access complications.

Quality assurance in surgical trials of arteriovenous grafts for haemodialysis: A systematic review, a narrative exploration and expert recommendations

BACKGROUND

Introducing new procedures and challenging established paradigms requires well-designed randomised controlled trials (RCT). However, RCT in surgery present unique challenges with much of treatment tailored to the individual patient circumstances, refined by experience and limited by organisational factors. There has been considerable debate over the outcomes of arteriovenous grafts (AVG) compared to AVF, but any differences may reflect differing practice and potential variability. It is essential, therefore, when considering an RCT of a novel surgical procedure or device that quality assurance (QA) is defined for both the new approach and the comparator. The aim of this systematic review was to evaluate the QA standards performed in RCT of AVG using a multi-national, multi-disciplinary approach and propose an approach for future RCT.

METHOD

The methods of this have been previously registered (PROSPERO: CRD420234284280) and published. In summary, a four-stage review was performed: identification of RCT of AVG, initial review, multidisciplinary appraisal of QA methods and reconciliation. QA measures were sought in four areas - generic, credentialing, standardisation and monitoring, with data abstracted by a multi-national, multi-speciality review body.

RESULTS

QA in RCT involving AVG in all four domains is highly variable, often sub-optimally described and has not improved over the past three decades. Few RCT established or defined a pre-RCT level of experience, none documented a pre-trial education programme, or had minimal standards of peri-operative management, no study had a defined pre-trial monitoring programme, and none assessed technical performance.

CONCLUSION

QA in RCT is a relatively new area that is expanding to ensure evidence is reliable and reproducible. This review demonstrates that QA has not previously been detailed, but can be measured in surgical RCT of vascular access, and that a four-domain approach can easily be implemented into future RCT.

Low Posterior Internal Jugular Vein Approach for Tunnelled Haemodialysis Catheter Insertion: A Report on Outcomes at a Single Centre

AIM

The impact of technical differences in cannulation technique for tunnelled haemodialysis catheter insertion is undetermined. We aimed to assess clinical outcomes of the low posterior approach for internal jugular vein tunnelled catheter placement.

METHODS

A retrospective audit was undertaken on consecutive tunnelled catheter procedures performed at a single centre between January 2016 and June 2022. Only catheters specifically placed with a low posterior internal jugular approach were included. The study's primary outcome was 12-month catheter survival, evaluated using the Kaplan-Meier survival curve and log-rank test. Secondary outcomes included catheter performance and procedure-related complications.

RESULTS

During the study period, 391 tunnelled internal jugular haemodialysis catheters were inserted in 272 patients using the low posterior technique. The 12-month primary patency rate was 68%. Catheter insertion was successful in 96% of cases. Peri-procedural complications occurred in 4% of cases, most frequently bleeding. The most common reasons for catheter loss were dysfunction (10%) and bacteraemia (6%). The best predictors of catheter failure were advanced age (HR 1.02, 95% CI 1.00-1.04) and in-centre dialysis treatment locality (HR 2.04, 95% CI 1.19-3.45).

CONCLUSION

The low posterior approach for internal jugular vein tunnelled catheter insertion is effective and safe. We demonstrated a 12-month catheter survival rate of 68%. Further research comparing the low posterior approach with other internal jugular vein cannulation techniques is warranted.

What are the observed procedural costs of vascular access surgery? Protocol for a systematic review

INTRODUCTION

A central component in the introduction of a novel surgical procedure or technique is an evaluation of its cost efficiency when compared with a benchmark standard of care. Accurate assessment of costs is thus essential in ensuring appropriate allocation of resources within a healthcare system. The treatment of kidney failure requires a significant volume of resources, and vascular access provision is the main modifiable cost. The costs of providing this service are obscured by generic NHS reference costs, which lack adequate granularity to allow meaningful comparisons between treatments. The aim of this systematic review will be to assess the reporting of procedural costs in all published economic analyses of vascular access surgery and perform a comparison of the reported procedural costs involved in arteriovenous fistula (AVF) and arteriovenous graft (AVG) creation. This will provide an estimate as to the accuracy of the NHS reference costs in this field.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed. A systematic search will be performed of the MEDLINE, Embase and Cochrane databases to identify full-text economic analyses of vascular access for haemodialysis in which the procedural cost of AVF or AVG creation is reported. Publications in English from 1 January 2000 to 30 August 2023, will be eligible for inclusion. Studies will be selected by title and abstract review, followed by a full-text review using inclusion and exclusion criteria. Studies not reporting the procedural costs of surgery will be excluded. Data collected will pertain to procedural costs of AVF and AVG creation. Costs will be adjusted to a common currency using a gross domestic product (GDP) deflator index and conversion rates based on purchasing power parities for GDP. Comparison with NHS reference costs will indicate their reliability for use in future economic analyses in this field.

ETHICS AND DISSEMINATION

Ethical approval is not required for this systematic review. Findings will be disseminated through peer-reviewed publications and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42023458779.

A national co-design workshop of a mobile-based application for vascular access as a patient decision aid

BACKGROUND

Increasing options for vascular access have increased the need for more effective communication to optimize patient engagement and ensure effective consent. An advanced prototype of the mobile application (VA App) was developed over 3 years as a patient decision aid. For the first time, entry to the 2021 UK Kidney Week was opened to all professions and patients and was held online. The VA App was presented in an inter-active session. This report summarizes the findings.

METHODS

A 30-min interactive session was allocated with the session delivered in four sections: (1) demographic data was collected; (2) an overall opinion was obtained about current patient information sources and satisfaction with these; (3) the participants were asked a series of eight questions regarding the main problem areas previously identified; (4) following a 6-min demonstration video, the participants were then re-asked the same questions to determine if the VA App would improve/worsen these areas.

RESULTS

Completed data from 30 participants showed great variation in all demographics. The most cited source was verbal and rated the best, whilst all other sources were felt to be poor by 90%. All eight aspects of current information sources rated poorly. There was a unanimous agreement that the VA App could make this better. Interestingly, when the eight aspects were ranked by order of the worst to best, this matched the order of the benefits of the VA App.

DISCUSSION

This is the first report of an on-line, multi-professional co-design workshop. With a unanimous view that current systems are very limited and that better patient information systems are required, the VA App was found to be a potential solution as a patient decision aid. Interestingly, paper leaflets were widely viewed as the least used and the least effective mechanism for communicating information to patients. Funding for a commercially produced mobile application has been secured and will be further tested in the near future.

Early-cannulation arteriovenous grafts: Multidisciplinary learning is essential to optimize outcomes

BACKGROUND

It is likely that there will be an increasing role for early-cannulation arteriovenous grafts (ecAVG) with a wider recognition of the need to tailor vascular access to avoid futile procedures and unnecessary TCVC. However, experience of these products is not common and limited to early surgical adopters, with little information on the systemic changes and multi-disciplinary care needed to optimize outcomes. The aim of this study was to report the impact of a multi-disciplinary approach on quantifiable outcomes.

METHODS

A retrospective analysis of a prospectively maintained database of 295 ecAVG implanted over an 8-year time-period was performed. Indicative outcomes were chosen to reflect nephrology (patient selection), nursing care (cannulation complications of infection and pseudoaneurysm) and radiology (thrombosis) on cumulative impact (functional patency) over three distinct time periods.

RESULTS

The incidence of ecAVG increased 10-fold over the three time periods. The use of ecAVG changed significantly from salvage tertiary access to TCVC avoidance and salvage of existing AVF. Nursing complications reduced markedly with significantly fewer over-cannulation episodes and pseudo-aneurysms. With an improved pro-active surveillance programme, the time to first thrombosis doubled and the risk of thrombosis halved. Ultimately this resulted in significantly improved functional patency with a risk of ecAVG loss less than one-third by the last time-period.

CONCLUSIONS

All aspects of ecAVG use require scrutiny and critical appraisal. Failure or success is not simply achieved by performing good technical surgery with an efficacious product, but by the care taken across a wide range of elements spanning case selection, implantation, use and maintenance.

Quality assurance in surgical trials of arteriovenous grafts for haemodialysis: protocol for a systematic review

INTRODUCTION

Decisions regarding the optimal vascular access for haemodialysis patients are becoming increasingly complex, and the provision of vascular access is open to variations in systems of care as well as surgical experience and practice. Two main surgical options are recognised: arteriovenous fistula and arteriovenous graft (AVG). All recommendations regarding AVG are based on a limited number of randomised controlled trials (RCTs). It is essential that when considering an RCT of a surgical procedure, an appropriate definition of quality assurance (QA) is made for both the new approach and the comparator, otherwise replication of results or implementation into clinical practice may differ from published results. The aim of this systematic review will be to assess the methodological quality of RCT involving AVG, and the QA measures implemented in delivering interventions in these trials.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed. A systematic search will be performed of the MEDLINE, Embase and Cochrane databases to identify relevant literature. Studies will be selected by title and abstract review, followed by a full-text review using inclusion and exclusion criteria. Data collected will pertain to generic measures of QA, credentialing of investigators, procedural standardisation and performance monitoring. Trial methodology will be compared against a standardised template developed by a multinational, multispecialty review body with experience in vascular access. A narrative approach will be taken to synthesise and report data.

ETHICS AND DISSEMINATION

Ethical approval is not required as it is a protocol for a systematic review. Findings will be disseminated through peer-reviewed publications and conference presentations, with the ultimate aim of providing recommendations for future RCT of AVG design.

Prognosis Factors of Patients Undergoing Renal Replacement Therapy

BACKGROUND

Survival in patients with end-stage kidney disease (ESKD) on renal replacement therapy (RRT) is less than that of the general population of the same age, and depends on patient factors, the medical care received, and the type of RRT used. The objective of this study is to analyze the factors associated with survival in patients undergoing RRT.

METHODS

We conducted a retrospective observational study of adult patients with an incident of ESKD on RRT in Andalusia from 1 January 2008 to 31 December 2018. Patient characteristics, nephrological care received, and survival from the beginning of RRT were evaluated. A survival model for the patient was developed according to the variables studied.

RESULTS

A total of 11,551 patients were included. Median survival was 6.8 years (95% CI (6.6; 7.0)). After starting RRT, survival at one year and five years was 88.7% (95% CI (88.1; 89.3)) and 59.4% (95% CI (58.4; 60.4)), respectively. Age, initial comorbidity, diabetic nephropathy, and a venous catheter were independent risk factors. However, non-urgent initiation of RRT and follow-up in consultations for more than six months had a protective effect. It was identified that renal transplantation (RT) was the most influential independent factor in patient survival, with a risk ratio of 0.13 (95% CI (0.11; 0.14)).

CONCLUSIONS

The receiving of a kidney transplant was the most beneficial modifiable factor in the survival of incident patients on RRT. We consider that the mortality of the renal replacement treatment should be adjusted, taking into account both modifiable and nonmodifiable factors to achieve a more precise and comparable interpretation.

Pre-emptive or reactive treatment, angioplasty or stent-graft? The outcome for interventions for venous stenosis in early-cannulation arteriovenous grafts

BACKGROUND

Early-cannulation arteriovenous grafts (ecAVG) have good initial patency, but frequent episodes of reintervention for venous stenosis (VS) and thrombosis limit their use. Stent grafts (SG) have shown promise in reducing re-interventions and improving functional patency for dysfunctional ecAVG and recurrent VS. There is little data on the impact of stent grafts as the first elective procedure for VS. The aim of this study was to determine firstly, if treating VS whilst asymptomatic has a better outcome than treating after presentation with thrombosis; and secondly, to determine the best initial treatment for asymptomatic VS: SG or angioplasty.

METHODS

A retrospective study was performed of 259 ecAVG with a sutured anastomosis. The case-mix and outcomes of 153 who presented with VS was analysed by presentation (elective at surveillance or emergency following thrombosis), and then for only elective patients, by treatment (SG vs angioplasty).

RESULTS

There was no significant difference in case-mix and time to presentation by mode of presentation (100 elective and 53 with thrombosis) other than a higher rate of pro-thrombotic disorders in thrombosed ecAVG. Thrombosed ecAVG had poorer outcomes with increased re-intervention rates and thrombosis in the following year, and reduced long-term functional patency. In patients presenting electively, primary SG rather than angioplasty led to significantly reduced thrombosis rates, a longer time to re-intervention in the following year, and superior long-term functional patency. The use of SG was the same in both groups. Both the mode of presentation and the type of intervention performed were independently predictive of a poorer subsequent functional patency.

CONCLUSIONS

Primary elective stent-grafting may be the optimal strategy to reducing maintenance costs with ecAVG.

Multifaceted intervention to reduce haemodialysis catheter related bloodstream infections: REDUCCTION stepped wedge, cluster randomised trial

OBJECTIVE

To identify whether multifaceted interventions, or care bundles, reduce catheter related bloodstream infections (CRBSIs) from central venous catheters used for haemodialysis.

DESIGN

Stepped wedge, cluster randomised design.

SETTING

37 renal services across Australia.

PARTICIPANTS

All adults (age ≥18 years) under the care of a renal service who required insertion of a new haemodialysis catheter.

INTERVENTIONS

After a baseline observational phase, a service-wide, multifaceted intervention bundle that included elements of catheter care (insertion, maintenance, and removal) was implemented at one of three randomly assigned time points (12 at the first time point, 12 at the second, and 13 at the third) between 20 December 2016 and 31 March 2020.

MAIN OUTCOMES MEASURE

The primary endpoint was the rate of CRBSI in the baseline phase compared with intervention phase at the renal service level using the intention-to-treat principle.

RESULTS

1.14 million haemodialysis catheter days of use were monitored across 6364 patients. Patient characteristics were similar across baseline and intervention phases. 315 CRBSIs occurred (158 in the baseline phase and 157 in the intervention phase), with a rate of 0.21 per 1000 days of catheter use in the baseline phase and 0.29 per 1000 days in the intervention phase, giving an incidence rate ratio of 1.37 (95% confidence interval 0.85 to 2.21; P=0.20). This translates to one in 10 patients who undergo dialysis for a year with a catheter experiencing an episode of CRBSI.

CONCLUSIONS

Among patients who require a haemodialysis catheter, the implementation of a multifaceted intervention did not reduce the rate of CRBSI. Multifaceted interventions to prevent CRBSI might not be effective in clinical practice settings.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry ACTRN12616000830493.

A critical review of surgical strategies to minimise venous stenosis in arteriovenous grafts

It is inevitable that complications arising from surgical procedures are ascribed to surgical technique, and this applies to venous stenosis (VS) in arteriovenous grafts. However, despite a wide range of cellular studies, computer modelling, observational series and clinical trials, there remains uncertainty on whether surgical technique contributes to VS. This article reviews evidence from basic science, fluid dynamics and clinical data to try and rationalise the main surgical options to modify the occurrence of venous stenosis. There is sufficient data from diverse sources to make recommendations on clinical practice (size of target vein, shape of anastomosis, angle of approach, distance from venous needling, trauma to the target vein) whilst at the same time this emphasises the need to carefully report the practical aspects of surgical technique in future clinical trials.

Early cannulation versus standard arteriovenous grafts in hemodialysis patients: a randomized clinical study

OBJECTIVE

Arteriovenous grafts (AVGs) are frequently needed in hemodialysis (HD) patients with unsuitable superficial veins. First cannulation of standard arteriovenous grafts (sAVGs) still require about 2 weeks after implantation. Early cannulation arteriovenous grafts (eAVGs) were suggested to overcome this shortcoming. The present randomized study proposed to compare the clinical outcomes of sAVGs and eAVGs in HD patients.

METHODS

The present single-center randomized clinical study recruited 477 HD patients indicated for AVG creation. They included 236 in the sAVG group and 241 in the eAVG group. Eligible patients were simply randomized and allocated to the studied groups using 1:1 allocation ratio. Blinding was secured using the sealed envelope technique. Enrolled patients were followed up for 12 months. The primary outcome in the present study was primary, primary assisted, and secondary patency rates at 12 months. Other outcome parameters included time to first cannulation, graft complications, and mortality.

RESULTS

Comparison between the studied groups regarding the primary outcomes revealed no statistically significant differences. Primary patency rate was 65.7% and 68.0% (P = .58) at 6 months and 53.8% and 56.4% (P = .57) at 12 months in the sAVG and eAVG groups, respectively. Primary assisted patency rate was 70.8% and 69.7% (P = .8) in patients with sAVG and eAVG, whereas the reported rates at 12 months were 59.3% and 61.0% (P = .71), respectively. Secondary patency rate was 78.4% and 73.9% (P = .25) at 6 months and 67.8% and 69.7% (P = .65) at 12 months in the sAVG and eAVG groups, respectively. As expected, patients in the eAVG group experienced significantly earlier cannulation when compared with patients in the sAVG group (median, 3.0 days; range, 1.0-9.0 days vs 19.0 days; range, 15.0-22.0 days; P < .001).

CONCLUSIONS

Patients in the eAVG group have comparable outcomes to those in the sAVG group at 12 months with the added advantage of earlier time to first cannulation.

Patient characteristics predict patency of early-cannulation arteriovenous grafts

There is a new emphasis on tailoring appropriate vascular access for hemodialysis to patients and their life-plans, but there is little known about the optimal use of newer devices such as early-cannulation arteriovenous grafts (ecAVG), with studies utilising them in a wide variety of situations. The aim of this study was to determine if the outcome of ecAVG can be predicted by patient characteristics known pre-operatively. This retrospective analysis of 278 consecutive ecAVG with minimum one-year follow-up correlated functional patency with demographic data, renal history, renal replacement and vascular access history. On univariate analysis, aetiology of renal disease, indication for an ecAVG, the number of previous tunnelled central venous catheters (TCVC) prior to insertion of an ecAVG, peripheral vascular disease, and BMI were significant associates with functional patency. On multivariate analysis the number of previous TCVC, the presence of peripheral vascular disease and indication were independently associated with outcome after allowing for age, sex and BMI. When selecting for vascular access, understanding the clinical circumstances such as indication and previous vascular access can identify patients with differing outcomes. Importantly, strategies that result in TCVC exposure have an independent and cumulative association with decreasing long-term patency for subsequent ecAVG. As such, TCVC exposure is best avoided or minimised particularly when ecAVG can be considered.

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.

Early-Cannulation Arteriovenous Grafts Are Safe and Effective in Avoiding Recurrent Tunneled Central Catheter Infection

OBJECTIVES

Tunneled central venous catheter infection (TCVCi) is a common complication that often necessitates removal of the TCVC and replacement by a further TCVC. Theoretically, insertion of an early - cannulation graft (ecAVG) early after TCVC infection is possible but not widely practiced with concerns over safety and infection in the ecAVG. With 8 years of ecAVG experience, the aim of this study was to compare the outcomes following TCVC infection, comparing replacement with TCVC (TCVCr) versus immediate ecAVG (ecAVGr).

DESIGN

Retrospective comparison of 2 cohorts, who underwent replacement of an infected TCVC either by an early cannulation graft (n = 18) or by a further central catheter (n = 39).

METHODS

Data were abstracted from a prospectively completed electronic patient record and collected on patient demographics, TCVC insertion, duration and infection, including culture proven bacteriaemia and subsequent access interventions.

RESULTS

Eighteen of 299 patients identified from 2012 to 2020 had an ecAVG implanted as treatment for a TCVCi. In a 1-year time-period (January 1, 2015-December 31, 2015) out of 222 TCVC inserted, 39 were as a replacement following a TCVCi. No patient with an ecAVGr developed an immediate infection, nor complication from the procedure. The rate of subsequent vascular access infection was significantly more frequent for those with a TCVCr than with an ecAVGr (0.6 vs. 0.1/patient/1000 HD days, P< 0.000). The number of further TCVC required was significantly higher in the TCVCr group (7.1 vs. 0.4/patient/1000 HD days, P= 0.000).

CONCLUSIONS

An ecAVG early following a TCVC infection is safe, reduces the incidence of subsequent infectious complications and reduces the number of TCVC required, with a better functional patency.

Is the Fistula First Approach still valid?

The Fistula First Breakthrough Initiative, founded in 2003, was responsible for changing the access profile in the United States, increasing the prevalence of arteriovenous fistulas (AVFs) by 50% and reducing that of arteriovenous grafts (AVGs). However, the concept that AVFs are always the best access for all patients has been challenged. Discussion points are: (1) the questionable survival benefit of AVFs over AVGs, if one takes into account the high rates of primary AVF failure; (2) the potential benefits of using AVGs for greater primary success; and (3) the questionable benefit of AVFs over AVGs in patients with shorter survival, such as the elderly. The high rate of primary failure and maturation procedures leads to prolonged use of catheters, and it is one of the weaknesses of the fistula first strategy. AVGs proved to be better than AVFs as a second access after the failure of a first AVF, and in patients with non-ideal vessels, with greater primary success and reduced catheter times. AVGs appear to have a similar survival to AVFs in patients older than 80 years, with less primary failures and interventions to promote maturation. The most recent KDOQUI guidelines suggest an individualized approach in access planning, taking into account life expectancy, comorbidities and individual vascular characteristics, with the aim of chosing adequate access for the right patient, at the right time, for the right reasons.

Application and implications of a standardised reporting system for arteriovenous access graft infection

INTRODUCTION

The perception that arteriovenous graft infection (AVGi) is frequent and severe is not based on contemporary data from large units using modern AVG. Furthermore, older reports compounded misperceptions by using non-standardised reporting that prevents easy comparison against the alternative modalities. The aim of this article is to use a recently published reporting scheme to analyse the frequency, management and outcome of AVGi in a large series of sequential early-cannulation AVG with long-term follow-up.

METHODS

A single-center series analysis was performed of 277 early-cannulation AVG with minimum 1-year follow-up (total 120,082 days). Infections relating to the AVG were classified, root-cause analysed and the outcomes presented.

RESULTS

Sixteen percent of all AVG implanted (51 episodes) developed infection related to the AVG. Primary AVGi (related to the insertion procedure or within 28 days) occurred in 9 (3%); secondary AVGi (related to AVG in use) occurred 33 times (rate 0.27/1000 haemodialysis days), at a mean of 382 days, and tertiary AVGi (in AVG no longer in use) occurred nine times. Only 1/3 of all AVGi led to bacteraemia, and ½ did not lead to loss of functional access.

SUMMARY

AVG infection is not common, caused a systemic infection in only one-third, did not lead to metastatic infection, and importantly, was treatable without loss of access in one-half of all cases. Using an objective system that discriminates between aetiology and outcome allows a more complete objective understanding of relative infection risks and outcomes for AVG that can inform discussions with patients requiring vascular access for haemodialysis.

Single Asian Center Experience Using the Flixene™ Early Cannulation Graft for Hemodialysis Access Creation

BACKGROUND

The aim of this study was to review the efficacy of the Flixene™ (Atrium™, Hudson, NH, USA) hemodialysis arterio-venous graft (AVG) in a multiethnic Asian cohort of patients with end-stage renal failure (ESRF). Primary outcome was graft primary patency rate and secondary end points included graft usability, time to cannulation, reinterventions required for access salvage, complications, and patient mortality.

METHODS

Single-center, single-arm, multi-investigator nonrandomized retrospective study. Patients with ESRF who underwent Flixene™ graft implantation over a two-year period (January 2017 - December 2018) were included to allow at least one-year follow-up. Demographics, procedural and follow-up data were collected from the hospital electronic medical records.

RESULTS

About 48 patients (49 AVG) were included. There were 24 (50%) men; mean age 63.7 (IQR 58.2-71.3) years. Technical success rate was 45/49 (91.8%); 4/49 (8.2%) AVG created did not reach cannulation. 11/49 (22.4%) and 28/49 (57.1%) achieved cannulation within 1 and 2 weeks, respectively. 6- and 12- month primary patencies were 33.5% and 19.6%, respectively. Primary-assisted patency rates were 46.6% and 29.6% at the same time intervals. Secondary patency rate was 77.6% and 63.9% at 6 and 12 months, respectively. There were 6 (12.2%) graft infections requiring explant and one-year mortality was 14%.

CONCLUSIONS

Our experience with the Flixene™ early cannulation graft is comparable with other AVGs in terms of patency and infection rates. However, early cannulation rates are lower than in other case series.

Spontaneous Dislodgement of Tunneled Dialysis Catheters after De Novo versus Over-The-Wire-Exchange Placement

PURPOSE

To evaluate dislodgement of tunneled dialysis catheters (TDCs) in de novo (DN) placement with ultrasound versus over-the-wire exchange (OTWE).

MATERIALS AND METHODS

Data were collected retrospectively on all TDC placements at this institution from 2001 to 2019 and were excluded if no removal date was recorded or if dwell time was more than 365 days. Information on TDC brand, placement, insertion/removal, and removal reason were collected. Multiple logistic regression evaluated factors associated with TDC dislodgement. DN placement and OTWE were compared for rate of dislodgement (generalized estimating equations method) and TDC dwell time (survival analysis).

RESULTS

In total, 5328 TDCs were included with 66% (3522) placed DN and 32% (1727) via OTWE. Mean dwell time was 65 ± 72 days, and dislodgement occurred in 4% (224). TDC dislodgement rates in the DN and OTWE groups were 0.48 and 0.93 per 1000 catheter days, respectively. Brand (Ash Split vs. VectorFlow), placement technique (OTWE vs. DN), laterality (left vs. right), and site (left vs. right internal jugular vein) were significant predictors of dislodgement. OTWE placement exhibited 1.7 times the odds of dislodgement (95% confidence interval, 1.2-2.6; P = .004) compared to DN and had significantly higher probability of dislodgement across time (hazard ratio = 2.0; P < .001) compared to DN. Dislodgement rates for OTWE vs. DN were 8% vs. 3% (3 months), 13% vs. 6% (6 months), and 38% vs. 17% (1 year).

CONCLUSIONS

TDC spontaneous dislodgement rates were significantly and consistently higher after OTWE compared to DN placement. These data support more careful attention to catheter fixation after OTWE placement.

REDUcing the burden of dialysis Catheter ComplicaTIOns: a National approach (REDUCCTION) - design and baseline results

BACKGROUND

Patients with hemodialysis central venous catheters (HD CVCs) are susceptible to health care-associated infections, particularly hemodialysis catheter-related bloodstream infection (HD-CRBSI), which is associated with high mortality and health care costs. There have been few systematic attempts to reduce this burden and clinical practice remains highly variable. This manuscript will summarize the challenges in preventing HD-CRBSI and describe the methodology of the REDUcing the burden of dialysis Catheter ComplicaTIOns: a National approach (REDUCCTION) trial.

METHODS

The REDUCCTION trial is a stepped-wedge cluster randomized trial of a suite of clinical interventions aimed at reducing HD-CRBSI across Australia. It clusters the intervention at the renal-service level with implementation randomly timed across three tranches. The primary outcome is the effect of this intervention upon the rate of HD-CRBSI. Patients who receive an HD CVC at a participating renal service are eligible for inclusion. A customized data collection tool allows near-to-real-time reporting of the number of active catheters, total exposure to catheters over time, and rates of HD-CRBSI in each service. The interventions are centered around the insertion, maintenance, and removal of HD CVC, informed by the most current evidence at the time of design (mid-2018).

RESULTS

A total of 37 renal services are participating in the trial. Data collection is ongoing with results expected in the last quarter of 2020. The baseline phase of the study has collected provisional data on 5385 catheters in 3615 participants, representing 603,506 days of HD CVC exposure.

CONCLUSIONS

The REDUCCTION trial systematically measures the use of HD CVCs at a national level in Australia, accurately determines the rate of HD-CRBSI, and tests the effect of a multifaceted, evidence-based intervention upon the rate of HD-CRBSI. These results will have global relevance in nephrology and other specialties commonly using CVCs.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

The management of lower limb arteriovenous grafts in the perioperative period following renal transplantation

BACKGROUND

The presence of a lower limb arteriovenous graft (LL-AVG) is indicative of a group of complex hemodialysis patients who have precarious long-term vascular access. The aim of this study is to describe our experience of the clinical decisions and interactions between LL-AVG and renal transplantation.

METHODS

The records of 23 patients who received a transplant in the presence of a LL-AVG between 2010 and 2018 were analyzed: firstly, to determine whether patients with a LL-AVG received extended criteria transplants, the implantation procedure, and the management of the LL-AVG in the post-operative period.

RESULTS

Seventeen patients (74%) had "end-stage access" and were thus considered for all offer stratified by the kidney donor profile index (KDPI) and donor type (DBD or DCD). In eleven patients (48%), a kidney with a high risk of delayed graft function was transplanted. Same-sided renal transplantation occurred in only 35% of cases, and of these, only one LL-AVG was ligated immediately to improve transplant perfusion.

CONCLUSION

A patient-based approach applied in decision-making on management of the LL-AVG post-transplantation should include (a) the likelihood of delayed graft function, (b) the need for post-operative hemodialysis, (c) the side of proposed transplant compared to the LL-AVG, and (d) local complications.

Prevention of Bloodstream Infections in Patients Undergoing Hemodialysis

Bloodstream infections are an important cause of hospitalizations, morbidity, and mortality in patients receiving hemodialysis. Eliminating bloodstream infections in the hemodialysis setting has been the focus of the Centers for Disease Control and Prevention (CDC) Making Dialysis Safer for Patients Coalition and, more recently, the CDC's partnership with the American Society of Nephrology's Nephrologists Transforming Dialysis Safety Initiative. The majority of vascular access-associated bloodstream infections occur in patients dialyzing with central vein catheters. The CDC's core interventions for bloodstream infection prevention are the gold standard for catheter care in the hemodialysis setting and have been proven to be effective in reducing catheter-associated bloodstream infection. However, in the United States hemodialysis catheter-associated bloodstream infections continue to occur at unacceptable rates, possibly because of lapses in adherence to strict aseptic technique, or additional factors not addressed by the CDC's core interventions. There is a clear need for novel prophylactic therapies. This review highlights the recent advances and includes a discussion about the potential limitations and adverse effects associated with each option.

Hemodialysis access cost comparisons among incident tunneled catheter patients

Background:

Arteriovenous fistula is the ideal hemodialysis access, but most patients start with tunneled dialysis catheter. Arteriovenous fistula and arteriovenous graft surgery may reduce tunneled dialysis catheter use and also increase procedural expenses. We compared Medicare costs associated with arteriovenous fistula, arteriovenous graft, and tunneled dialysis catheter.

Methods:

Using the US Renal Data System, we identified incident hemodialysis patients in 2008 who started with tunneled dialysis catheter, survived at least 90 days, and had adequate Medicare records for analysis. We followed them until death or end of 2011; access modality was based on billing evidence of arteriovenous fistula or arteriovenous graft creation. We assumed patients without such records remained with tunneled dialysis catheter. We generated multivariate linear regression models predicting Medicare expenditures, censoring costs when patients died; we included all payments to physicians and institutions. We also created algorithms to identify access-related costs.

Results:

There were 113,505 patients in the US Renal Data System who started hemodialysis in 2008, of whom 51,002 Medicare patients met inclusion criteria. Of that group, 41,532 (81%) began with tunneled dialysis catheter; 27,064 patients were in the final analysis file. In the first 90 days after hemodialysis initiation, 6100 (22.5%) received arteriovenous fistula, 1813 (6.7%) arteriovenous graft, and 19,151 (70.8%) stayed with tunneled dialysis catheter. Annualized access costs by modality were tunneled dialysis catheter US$13,625 (95% confidence interval: US$13,426–US$13,285); arteriovenous fistula US$16,864 (95% confidence interval: US$16,533–US$17,194); and arteriovenous graft US$20,961 (95% confidence interval: US$20,967–US$21,654; p < .001). Multivariate linear regression demonstrated that staying with tunneled dialysis catheter had lowest access-related costs, arteriovenous fistula was intermediate, and those who underwent arteriovenous graft surgery were highest (p < .021). Access type was not significantly associated with total costs. Additional arteriovenous fistula and arteriovenous graft creation (US$3525 and US$3804 per access per year, respectively) and open and endovascular access-related interventions (US$3102 and US$3569 per procedure per year, respectively; all p < .001) were important predictors of increased cost.

Conclusions:

Among patients starting hemodialysis with tunneled dialysis catheter, continued tunneled dialysis catheter use is associated with lowest access-related cost. Both endovascular and open interventions are associated with significant additional costs. Further investigation is warranted to develop efficient patient-centered strategies for hemodialysis access.

The first 365 days on haemodialysis: variation in the haemodialysis access journey and its associated burden

Background

The modality by which haemodialysis (HD) is delivered [arteriovenous fistula (AVF), arteriovenous graft (AVG) or central venous catheter (CVC)] varies widely and is influenced by clinical evidence, patient factors and the prevailing service configuration. The aim of this study was to determine the outcome and impact of access strategy on patient outcome by mapping out the HD journey in a cohort of incident patients.

Methods

A 2-year cohort of consecutive incident HD patients from the point of referral for first dialysis access to completion of the first 365 days of HD was prospectively reviewed. Data were sought on access type; radiological, surgical and other access-related activity; bacteraemic events; admission rates and cumulative financial cost.

Results

A total of 144 patients started RRT for the first time with HD over the 2-year period. All were followed up to 1 year after starting HD, generating a total of 47 753 observed HD days.  Activity prior to starting HD for the full cohort was found to average 0.92 arteriovenous (AV) access creation procedures, 0.40 CVC insertions, 0.14 interventional radiology procedures and 0.41 ultrasound examinations per patient. The small number of patients who started on an AVG had a tendency towards higher pre-HD surgical and imaging activity than those who started on an AVF or CVC.  Activity after starting HD varied greatly with the access type used at the start of HD, with AVF patients experiencing less hospitalization, procedure and imaging activity and financial costs compared with those who start HD with a CVC. Patients who started on an AVG had a tendency towards lower surgical activity rates and financial costs than those who started on a CVC.

Conclusions

Providing, maintaining and dealing with the complications of HD vascular access places a significant burden of activity that is shared across nephrology, surgery and imaging services. A well-functioning AVF is associated with the lowest burden, whereas a failed AVF or CVC access is associated with the highest burden. Patient journeys are shaped by the vascular access that they use and we suggest that the contemporary pursuit of HD access should focus on delivering personalized access solutions.

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.

A novel hybrid silk-fibroin/polyurethane three-layered vascular graft: towards in situ tissue-engineered vascular accesses for haemodialysis

Clinically available alternatives of vascular access for long-term haemodialysis-currently limited to native arteriovenous fistulae and synthetic grafts-suffer from several drawbacks and are associated to high failure rates. Bioprosthetic grafts and tissue-engineered blood vessels are costly alternatives without clearly demonstrated increased performance. In situ tissue engineering could be the ideal approach to provide a vascular access that profits from the advantages of vascular grafts in the short-term (e.g. early cannulation) and of fistulae in the long-term (e.g. high success rates driven by biointegration). Hence, in this study a three-layered silk fibroin/polyurethane vascular graft was developed by electrospinning to be applied as long-term haemodialysis vascular access pursuing a 'hybrid' in situ engineering approach (i.e. based on a semi-degradable scaffold). This Silkothane^® graft was characterized concerning morphology, mechanics, physical properties, blood contact and vascular cell adhesion/viability. The full three-layered graft structure, influenced by the polyurethane presence, ensured mechanical properties that are a determinant factor for the success of a vascular access (e.g. vein-graft compliance matching). The Silkothane^® graft demonstrated early cannulation potential in line with self-sealing commercial synthetic arteriovenous grafts, and a degradability driven by enzymatic activity. Moreover, the fibroin-only layers and extracellular matrix-like morphology, presented by the graft, revealed to be crucial in providing a non-haemolytic character, long clotting time, and favourable adhesion of human umbilical vein endothelial cells with increasing viability after 3 and 7 d. Accordingly, the proposed approach may represent a step forward towards an in situ engineered hybrid vascular access with potentialities for vein-graft anastomosis stability, early cannulation, and biointegration.

Early Cannulation of Bovine Carotid Artery Graft Reduces Tunneled Dialysis Catheter-Related Complications: A Comparison of Bovine Carotid Artery Graft Versus Expanded Polytetrafluoroethylene Grafts in Hemodialysis Access

INTRODUCTION:

In patients who receive chronic hemodialysis but do not have autogenous venous conduit for a native dialysis access, nonautologous grafts serve as an alternative conduit of choice. This study compared the clinical outcome of hemodialysis access using bovine carotid artery graft (BCAG) and prosthetic polytetrafluoroethylene (PTFE) graft in patients who receive chronic hemodialysis.

METHODS:

An analysis of all patients undergoing hemodialysis using either BCAG or PTFE grafts from 2010 to 2017 was performed. Clinical outcomes were analyzed including graft patency as well as associated complications related to dialysis grafts and tunneled dialysis catheter (TDC).

RESULTS:

During the study period, 142 patients received BCAG and 128 patients received PTFE graft implantation for dialysis access. The mean duration from graft implantation to graft cannulation in the BCAG and PTFE group was 12.3 ± 8.5 days versus 43.5 ± 16.4, respectively ( P = .01). Bovine carotid artery graft group had a higher 2-year primary patency rate (33% vs 14%, P = .03) and assisted primary rate (57% vs 23%, P = .02) compared to the PTFE group. The 2-year secondary patency rates were similar between the 2 groups (56% vs 53%, P = .69). Complication rates in the BCAG and PTFE group was 1.69 ± 0.24 per patient-year versus 2.54 ± 0.48 per patient-year, respectively ( P = .01). Tunneled dialysis catheter-related infection was greater in the PTFE group compared to the BCAG group (10.87 ± 2.61 vs 5.69 ± 0.98 per 1000 TDC days; P = .02). Bovine carotid artery graft cohorts group required a mean of 1.69 interventions per patient-year, compared to 2.76 per patient-year for the PTFE group ( P = .03).

CONCLUSIONS:

Bovine carotid artery graft permits earlier cannulation for hemodialysis access with superior primary and assisted primary patency rates compared to PTFE grafts. Patients with BCAG experienced shorter indwelling TDC duration and less TDC-related complications compared to PTFE cohorts.

Immediate-access grafts provide comparable patency to standard grafts, with fewer reinterventions and catheter-related complications

BACKGROUND

No independent comparisons, with midterm follow-up, of standard arteriovenous grafts (SAVGs) and immediate-access arteriovenous grafts (IAAVGs) exist. The goal of this study was to compare "real-world" performance of SAVGs and IAAVGs.

METHODS

Consecutive patients who underwent placement of a hemodialysis graft between November 2014 and April 2016 were retrospectively identified from the electronic medical record and Vascular Quality Initiative database at two tertiary centers. Only primary graft placements were included for analysis. Patients were divided into two groups based on the type of graft implanted. Patients' comorbidities, graft configuration, operative characteristics, and follow-up were collected and analyzed with respect to primary and secondary patency. Additional outcomes included graft-related complications, time to first cannulation, time to tunneled catheter removal, catheter-related complications, and overall survival. Patency was determined from the time of the index procedure; χ², Kaplan-Meier, and Cox regression analyses were used, with the P value set as significant at < .05.

RESULTS

There were 210 grafts identified, 148 SAVGs and 62 IAAVGs. At baseline, the patients' characteristics were similar between groups, except for a greater prevalence of preoperative central venous occlusions in the IAAVG group (16.3% vs 6.8%; P < .04). Of the IAAVG group, 50 were Acuseal (W. L. Gore & Associates, Flagstaff, Ariz) and 12 were Flixene (Atrium Medical Corporation, Hudson, NH). Primary patency was similar at both 1 year (SAVG, 39.4%; IAAVG, 56.7%; P = .4) and 18 months (SAVG, 29.0%; IAAVG, 43.7%; P = .4). Secondary patency was similar at 1 year (SAVG, 50.7%; IAAVG, 52.1%; P = .73) and 18 months (SAVG, 42.3%; IAAVG, 46.3%; P = .73). Overall survival was 48% at 24 months. IAAVG patients required fewer overall additional procedures to maintain patency (mean number of procedures, 0.99 for SAVGs vs 0.61 for IAAVGs; P = .025). There was no difference in occurrence of steal syndrome (SAVG, 6.8%; IAAVG, 8.1%; P = .74) or graft infection (SAVG, 19.0%; IAAVG, 12.0%; P = .276). Seventy-five percent of all grafts were successfully cannulated, with shorter median time to first cannulation in the IAAVG group (6 days; interquartile range [IQR], 1-19 days) compared with the SAVG group (31 days; IQR, 26-47 days; P < .01). Of all pre-existing catheters, 65.75% were removed, with a shorter median time until catheter removal in the IAAVG cohort at 34 days (IQR, 22-50 days) vs 49 days (IQR, 39-67 days) in the SAVG group (P < .01). Catheter-related complications occurred less frequently in the IAAVG group (16.4% vs 2.9%; P < .045).

CONCLUSIONS

IAAVGs allow earlier cannulation and tunneled catheter removal, thereby significantly decreasing catheter-related complications. Patency and infection rates were similar between SAVGs and IAAVGs, but fewer secondary procedures were performed in IAAVGs.

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.

Current Experience and Midterm Follow-up of Immediate-Access Arteriovenous Grafts

BACKGROUND

No independent reviews, with midterm follow-up, of current experience with immediate-access arteriovenous grafts (IAAVGs) exist. The goal of this project was to assess the real-world performance of 2 different IAAVGs over a 2-year period at a large tertiary referral center.

METHODS

Between January 2014 and April 2016, all consecutive patients who underwent placement of Acuseal (Gore) or Flixine (Maquet) IAAVGs were identified for retrospective analysis from the electronic medical record and Vascular Quality Initiative database. Primary, primary-assisted and secondary patency rates, time to first cannulation, time to tunneled catheter removal, and overall survival were recorded.

RESULTS

Forty-three patients were identified to have undergone placement of IAAVG, 31 Acuseal (72%), and 12 Flixine (28%). Of the Acuseal cohort, 7 were implanted with outflow through a HeRO catheter system (Merit Medical). Mean follow-up time was 8.4 months. Overall survival was 57.4% at 18 months. Overall primary, primary assisted, and secondary patency at 18 months were 33.36%, 34.31%, and 51.03%, respectively. Eighty three percent of grafts were successfully cannulated, and 78% of preexisting catheters were removed. Mean time to successful graft cannulation and catheter removal were 14.85 and 32.26 days, respectively.

CONCLUSIONS

Real-world experience with novel arteriovenous access grafts is consistent with results from industry-sponsored studies. Early cannulation of immediate-access grafts can be successfully performed in a wide variety of patients. However, prolonged catheter dwell times persist despite increased rates of successful early-graft cannulation. Further study of methods for promoting catheter removal in this patient population is warranted.

How arteriovenous grafts could help to optimize vascular access management

A one-size-fits-all approach to vascular access for dialysis may be prejudicial. Arteriovenous fistulae (AVF) have high primary failure, failure to mature rate, and late-stage complications making them unsuitable choice for many patients. Aging of population with chronic kidney disease (CKD) coupled with venous injury during CKD stages depletes suitable superficial veins for AVF creation. The National Institutes of Health consortium demonstrated the difficulty in attaining a functional AVF in hemodialysis patients. Recognition of flaws in AVF and the quest to reduce catheter use bring to the fore the benefits of arteriovenous grafts (AVG). Advances in catheter technologies, flow, care, and antibiotic locks have resulted in significant improvement in catheter-related infections. However, widespread recognition of catheter-related complications like central vein stenosis, metastatic infections, and exhaustion of venous access sites preclude their being a viable alternative to AVF, furthering the need to explore AVG as a substitute. Placement of "early cannulation" AVG is a catheter sparing option in patients who are likely to have inadequate fistula maturation. Advances in biohybrid technology and tissue-engineered grafts are providing a robust opportunity to develop biocompatible graft materials with minimal tissue reactivity and thrombogenicity. Xenografts (bovine carotid artery grafts) are proving to be comparable and, in many cases, better than conventional polytetrafluoroethylene material. Older age, dialysis dependence, and smaller vein size are related to the appropriateness of AVG creation. An individualized approach in selecting optimal upper extremity vascular access option using patient-specific factors while incorporating the benefits of an AVG would greatly aid in achieving low catheter usage in the dialysis population.

Elderly patient: which vascular access? Choice and management of vascular access in the elderly patient

The optimal vascular access for elderly patients remains a challenge due to the difficult balance between risks and benefits in a population with increased comorbidity and decreased survival. Long dependence to central vein catheter, patient comorbidities, life expectancy, and complication rates are important influencing the indications for arteriovenous fistula or an arteriovenous graft. Although central vein catheters are simpler way to start a hemodialysis treatment, elderly patients are also at higher risk of death from infection or other complications associated with them more than for younger patients. The discussion revolves around the following key questions:

What are the limiting factors for a vascular access in the elderly patients? Central venous catheter—is it still an option for elderly patients? Is still the autologous arteriovenous fistula playing a pivotal role as hemodialysis access in the elderly patients? Are there any real surgical contraindication to perform a vascular access in elderly patients? Is the old age a limiting factor for the vascular access management?

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.

Controversies in vascular access

PURPOSE OF REVIEW

There is renewed interest in vascular access research, fueled by new perspectives and a critical re-examination of traditional thinking. This review summarizes important developments in vascular access from the past year, highlight areas of controversy, and makes recommendations for future research.

RECENT FINDINGS

Recent studies provide an innovative and critical look at the assumptions underlying the promotion of fistulas as the preferred form of vascular access and highlight the need for a randomized comparison of different forms of access. Promising work that will help determine predictors of fistula maturation and potentially improve patient selection is ongoing. The role of early cannulation grafts continues to generate interest, and new approaches to reducing the risk of catheter-related bacteremia show promise.

SUMMARY

The scientific community should capitalize on this opportunity to critically re-examine fundamental questions that have gone unanswered to date. High-quality randomized trials are needed to quantify the magnitude of benefit of different vascular access strategies, gather information about the risks, benefits, and cost-effectiveness of different approaches, and to get a clear view of the patient experience and how it is impacted by choice of vascular access.