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

A practical review of barriers and challenges to a definitive randomised trial of grafts versus fistula

A definitive randomised controlled trial of arteriovenous fistula (AVF) versus arteriovenous grafts (AVG) has been advocated for more than a decade, but as yet, none has been completed. The aim of this article is to summarise the theoretical barriers, review the difficulties in trial design and practicalities that have thus far prevented this from occurring.

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.

Vascular Access for Home Hemodialysis: A Perspective on Tunneled Central Venous Catheters at Home

Expansion of home hemodialysis (HHD) provides an opportunity to improve clinical outcomes, reduce cost of care, and address the staffing challenges currently faced in caring for patients with kidney failure on replacement therapy. To increase HHD expansion, current practices and barriers to home dialysis must be examined and addressed. One such barrier is vascular access for HHD; although tunneled hemodialysis central venous catheters (CVCs) have been used for decades, physicians still hesitate to send patients home without a mature, functional arteriovenous access. An expert panel of clinicians was convened by Outset Medical, a manufacturer of hemodialysis systems, to review the literature and generate consensus recommendations regarding the use of CVCs for HHD. Consistent with the most recent Kidney Disease Outcomes vascular access guidelines, the end-stage kidney disease life plan should be created via shared decision making for modality choices, with the corresponding dialysis access individualized for the patient, and for whom a CVC may represent the most appropriate vascular access to provide HHD.

Recruitment into randomised trials of arteriovenous grafts: A systematic review

Although randomised controlled trials (RCT) are considered the optimal form of evidence, there are relatively few in surgery. Surgical RCT are particularly likely to be discontinued with poor recruitment cited as a leading reason. Surgical RCT present challenges over and above those seen in drug trials as the treatment under study may vary between procedures, between surgeons in one unit, and between units in multi-centred RCT. The most contentious and debated area of vascular access remains the role of arteriovenous grafts, and thus the quality of the data that is used to support opinions, guidelines and recommendations is critical. The aim of this review was to determine the extent of variation in the planning and recruitment in all RCT involving AVG. The findings of this are stark: there have been only 31 RCT performed in 31 years, the vast majority of which exhibited major limitations severe enough to undermine the results. This underlines the need for better quality RCT and data, and further inform the design of future studies. Perhaps most fundamental is the planning for a RCT that accounts for the intended population, the uptake of a RCT and the attrition for the significant co-morbidity in this population.

Challenges and potential solutions to enrollment in a clinical trial of arteriovenous fistula vs arteriovenous graft vascular access strategy

This article presents the rationale, challenges, and adaptive strategies employed during the initiation and execution of the arteriovenous (AV) access trial-a multicenter randomized controlled trial (RCT) comparing AV fistulas and AV grafts for hemodialysis in older adults with major comorbidities. Motivated by shifts in epidemiologic landscapes and evolving guidelines moving away from a fistula-first approach and to more patient-centric approaches, the objective of this randomized controlled trial was to fill critical knowledge gaps in determining the optimal vascular access for this complex patient population. We outline the challenges encountered in patient recruitment along with measures employed to overcome these obstacles in recruitment. We emphasize the pivotal role of continuous research in overcoming these challenges, underscoring its necessity to achieve a thorough comprehension of optimal vascular access strategies for this complex patient population.

Comparison between transposed arteriovenous fistulas and arteriovenous graft for the hemodialysis patients: A meta-analysis and systematic review

It is challenging for a surgeon to determine the appropriate vascular access for hemodialysis patients whose cephalic vein is usually inaccessible. The purpose of the study is to compare the complications and patency rates between transposed arteriovenous fistulas (tAVF) and arteriovenous graft (AVG) for the hemodialysis patients. Studies were recruited from PubMed, Cochrane library, EMBASE, the web of science databases, and reviewing reference lists of related studies from the inception dates to September 2, 2021. Statistical analyses were conducted using the statistical tool Review Manager version5.3 (Cochrane Collaboration, London, UK). I2 > 50% was defined as a high degree of heterogeneity, and then a random-effects model was used. Otherwise, the fixed-effects model was used. Odds ratio with its 95% confidence interval (95% CI) was used. Thirty-three trials (26 retrospective studies, four randomized controlled trials, two prospective trials, and one controlled-comparative study) with 6430 enrolled participants were identified in our analysis. The results showed that tAVF was accompanied with lower thrombosis rate (103/1184 (8.69%) vs 257/1367 (18.80%); I2 = 45%; 95% CI, 0.34 (0.26, 0.45)) and infection rate (43/2031 (2.12%) vs 180/2147 (8.38%); I2 = 0%; 95% CI, 0.20 (0.14, 0.30)) than arteriovenous graft. The significantly better primary patency rates, secondary patency rates, and primary assisted patency rates during follow-up were found in tAVF. However, the failure rate and the prevalence of hematoma were significantly lower in AVG group. No evidence showed the rate of overall mortality, steal syndrome, and aneurysm reduced in tAVF. Our results showed that tAVF is a promising vascular access technique for hemodialysis patients whose cephalic vein is inaccessible. Our data showed that tAVF has less thrombosis, infection risk, and better patency rates when compared with AVG. However, more attentions need to be paid to transposed arteriovenous fistulas maturation and hematoma.

The clinical journey and healthcare resources required for dialysis access of end-stage kidney disease patients during their first year of hemodialysis

BACKGROUND

Creation and maintenance of dialysis vascular access (VA) is a major component of healthcare resource utilization and cost for patients newly started on hemodialysis (HD). Different VA format arises due to patient acceptance of anticipatory care versus late preparation, and clinical characteristics. This study reviews the clinical journey and resource utilization required for different VA formats in the first year of HD.

METHOD

Data of patients newly commenced on HD between July 2015 and June 2016 were reviewed. Patients were grouped by their VA format: (A) pre-emptive surgically created VA (SCVA), (B) tunneled central venous catheter (CVC) followed by SCVA creation, (C) long-term tunneled CVC only. Clinical events, number of investigations and procedures, hospital admissions, and incurred costs of the three groups were compared.

RESULTS

In the multivariable analysis, the cost incurred by the group A patients had no significant difference to that incurred in the group B patients (p = 0.08), while the cost of group C is significantly lower (p < 0.001). Both the 62.7% of group A with successful SCVA who avoided tunneled CVC usage, and those with a functionally matured SCVA in group B (66.1%), used fewer healthcare resources and incurred less cost for their access compared to those did not (p = 0.01, p = 0.02, respectively) during the first year of HD.

CONCLUSION

With comparable cost, a pre-emptive approach enables avoidance of tunneled CVC. Tunneled CVC only access format incurred lower cost and is suitable for carefully selected patients. Successful maturation of SCVA greatly affects patients' clinical journey and healthcare cost.

VasQ U.S. pivotal study demonstrates the safety and effectiveness of an external vascular support for arteriovenous fistula creation

OBJECTIVE

Arteriovenous fistula (AVF) creation is a commonly performed vascular operation that reports 6-month functional success rates as low as 50%. Recently, a nitinol external vascular support device, VasQ, has shown potential in studies outside the United States (U.S.) to improve AVF outcomes when implanted at creation. Here, the pivotal study results of this novel technology in treating patients in the U.S. are described.

METHODS

VasQ was implanted in 144 patients at 16 centers across the U.S. who were referred for creation of a new AVF and consented for enrollment in a 2-year, prospective, multicenter, single-arm, open-label study. Brachiocephalic (n = 129) and radiocephalic (n = 15) AVFs were analyzed. The primary endpoint was primary patency at 6 months compared against a performance goal of 55% derived from a systematic literature search. Safety endpoints included device-related events, ischemic steal, infection, aneurysm, and seroma at up to 6 months. Minimum arterial size was 2.0 mm; target veins were required to measure 2.5 to 6 mm. Key exclusion criteria were patients <18 or >80 years, those with known ipsilateral central venous occlusion, target cannulation zone venous depth greater than 8 mm, and New York Heart Association class 3 or 4.

RESULTS

Patients were 61% male, 53% White, 35% African American, and 14% Hispanic. Mean age was 60 years, and median body mass index was 30.4. Of the patients, 69% were diabetic, 66% were on dialysis at the time of creation, and 70% had a prior access surgery. At 6 months, steal was observed in 2.1%, infection in 0.7%, and no aneurysms or seromas were seen. Primary patency at 6 months was 66% (P < .021 vs performance goal). Physiological maturation was achieved in 92.4% of patients. Successful two-needle cannulation for patients that entered the study on dialysis was achieved in 88% of VasQ AVFs at a median of 56 days. Pre-dialysis patients who initiated dialysis during the study achieved two-needle cannulation in 81.6% VasQ AVFs. Interventions were required at a rate of 1.07 per patient year over the entire study period. Two-year cumulative patency was 76.6% (95% confidence interval, 67.9%-83.4%) with no statistical difference between patients requiring interventions and those that did not. No patency differences were observed between brachiocephalic and radiocephalic AVFs.

CONCLUSIONS

The U.S. pivotal study results demonstrated improved AVF outcomes and an excellent safety profile with VasQ use relative to traditional AVFs. Under the conditions of this trial, VasQ shows great promise in expeditiously and efficiently enhancing AVF functional success.

Outcomes of arteriovenous graft vs. fistula for haemodialysis access in the elderly: A systematic review and meta‑analysis

The impact of the type of vascular access on the outcomes in the elderly haemodialysis patients is still unclear. The goal of the present study was to compare survival outcomes in elderly haemodialysis patients who received either arteriovenous graft (AVG) or arteriovenous fistula (AVF). A systematic literature search was performed in EMBASE, Cochrane, MEDLINE, ScienceDirect and Google Scholar databases for papers published from January 1954 until January 2022. Risk of bias in the selected publications was assessed by Newcastle Ottawa scale or Cochrane risk of bias tool depending on the study design. Meta-analysis was carried out using the random-effects model. Data were reported as pooled odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI). A total of 12 studies were included in the analysis. The majority of the studies had poor quality. Elderly patients receiving AVG had significantly worse survival rate compared with patients that received AVF for the haemodialysis access, with a pooled HR of 1.38 (95% CI, 1.24-1.53; I²=79.9%). Pooled HR for access survival was 1.60 (95% CI, 1.54-1.66; I²=0%). Pooled OR for primary patency rate, maturation failure and infections were 1.81 (95% CI, 0.73-4.49; I²=79.2%), 0.33 (95% CI, 0.12-0.91; I²=70.4%) and 9.74 (95% CI, 2.60-36.49; I²=52.4%), respectively. These results suggested that in elderly patients undergoing haemodialysis, AVG was associated with reduced overall survival and access survival, and higher infection rate, compared with AVF. Notably, AVG was also associated with a lower risk of maturation failure, presenting a potential advantage in specific patient populations (study registration: PROSPERO, no. CRD42022313199).

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.

Quality of Life of Palestinian Patients on Hemodialysis: Cross-Sectional Observational Study

BACKGROUND

Hemodialysis is life-saving and life-altering, affecting patients' quality of life. The management of dialysis patients often focuses on renal replacement therapy to improve clinical outcomes and remove excess fluid; however, the patient's quality of life is often not factored in.

OBJECTIVE

This study aimed to explore the factors affecting the quality of life of patients on dialysis in Palestine using the Kidney Disease Quality of Life (KDQOL-SFTM) questionnaire.

METHODS

A multicenter cross-sectional observational study was conducted at multiple dialysis centers in Palestine, including 271 participants receiving renal replacement therapy. Demographics, socioeconomic, and disease status data were collected. The Arabic version of KDQOL-SFTM was used to assess dialysis patient quality of life. Statistical analysis was performed using SPSS to find correlations among patient factors and the questionnaire's three main domains, the kidney disease component summaries (KDCS), mental component summaries (MCS), and physical component summaries (PCS).

RESULTS

Mean KDCS, MCS, and PCS scores were 59.86, 47.10, and 41.15, respectively. KDC scores were lower among participants aged 40 years or older, with lower incomes, and with diabetes. PCS and MCS scores were lower among patients aged >40, less educated, and lower-income participants. There was a positive correlation between MCS and KDCS (r = 0.634, P-value <0.001), PCS and KDCS (r = 0.569, P-value <0.001), as well as MCS and PCS (r = 0.680, P-value <0.001).

CONCLUSION

In this study, the KDQOL-SFTM questionnaire revealed lower PCS scores among hemodialysis patients in Palestine. Furthermore, the three domains of the questionnaire were adversely affected by patient income and education status. In addition, physical role, work status, and emotional role showed the lowest scores among the three main domains. Therefore, continuous assessment of patients' quality of life during their journey of hemodialysis using the KDQOL-SFTM along with the clinical assessment will allow the healthcare professionals to provide interventions to optimize their care.

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).

Deep Learning-Based Digital Subtraction Angiography Characteristics in Nursing of Maintenance Hemodialysis Patients

This study is aimed at exploring the diagnostic value of digital subtraction angiography (DSA) based on faster region-based convolutional networks (Faster-RCNN) deep learning for maintenance hemodialysis (MHD) diseases and to provide a theoretical basis for clinical nursing. A total of 50 MHD patients who were clinically diagnosed in the Blood Purification Center were randomly divided into the control group and the experimental group (25 cases for each group). The control group was given routine nursing intervention, and the experimental group was given overall nursing intervention under the supervision of DSA. A faster RCNN multitarget detection network was constructed to analyze the average accuracy of various vascular structures in the test set. The self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were used to evaluate the degree of anxiety and depression. The urine volume before and after the operation, local hematoma after a puncture, the incidence of complications, and nursing satisfaction were recorded. The results showed that the average accuracy of the vein, internal carotid artery, circle of Willis, venous sinus, and venous vessels was 0.876, 0.916, 0.994, 0.925, and 0.732, respectively. The success rate of surgery in the experiment group was higher than that in the control group, and the difference had statistical significance (P < 0.05). The SAS score and SDS score in the experimental group were significantly lower than those in the control group (P < 0.05). The total incidence rate of complications in the experimental group (16.00%) was significantly lower than that in the control group (44.00%) (P < 0.05). The satisfaction rate of the experimental group was significantly higher than that of the control group (P < 0.05). The Faster-RCNN model had the best effect in differentiating the circle of Willis and a poor effect in differentiating venous vessels. DSA based on Faster-RCNN can significantly improve the success rate of puncture in MHD patients. The implementation of holistic nursing intervention under its supervision can significantly reduce postoperative complications and improve patient satisfaction with nursing compared with routine nursing.

Mortality in elderly patients starting hemodialysis program

BACKGROUND

The incidence of older patients over 80 years old with chronic kidney disease who start hemodialysis (HD) program has been increasing in the last decade.

METHODS

We aimed to identify risk factors for morbidity and mortality in patients older than 80 years with end-stage renal disease who started HD. We conducted a retrospective observational study of the Catalan Renal registry (RMRC).

RESULTS

A total of 2833 patients equal or older than 80 years (of 15,137) who started HD between 2002 and 2019 from the RMRC were included in the study. In this group, the first dialysis was performed through an arteriovenous fistula in 44%, percutaneous catheter in 28.2%, and tunneled catheter in 26.6%. Conventional dialysis was used in 65.7% and online HD in 34.3%. The most frequent cause of death was cardiac disease (21.8%), followed by social problems (20.4%) and infections (15.9%). Overall survival in older HD during the first year was 84% versus 91% in younger than 80 years (p < 0.001). Cox regression analysis identified the start of HD in the period 2002-2010, chronic obstructive pulmonary disease (COPD), and the onset of HD through vascular graft depicted as risk factors for first-year mortality after dialysis initiation in patients older than 80 years with end-stage renal disease who started HD.

CONCLUSIONS

In conclusion, patients older than 80 years who started HD program had higher mortality, especially those who presented exacerbation of kidney disease, those with COPD, and those who started with a vascular graft.

Shared decision-making in hemodialysis vascular access practice

Shared decision-making (SDM) is a process of collaborative deliberation in the dyadic patient-physician interaction whereby physicians inform the patients about the pros and cons of all available treatment options and reach an agreement with the patients on their preferred treatment plan. In hemodialysis vascular access practice, SDM advocates a deliberative approach based on the existence of reasonable alternatives-that is, arteriovenous fistula, arteriovenous graft, and central venous catheter-so that patients are able to form and share preferences about access options. In spite of its ethical imperative, SDM is not broadly applied in hemodialysis vascular access planning. Physicians and surgeons commonly deliver prescriptive fistula-centered recommendations concerning the approach to vascular access care. This paternalistic approach has been shaped by directions from long-held clinical practice guidelines and is reinforced by financial payment models linked with the prevalence of arteriovenous fistula in patients on hemodialysis. Awareness is growing that what may have initially seemed a medically and surgically appropriate approach might not always be focused on each individual's goals of care. Clinician's recommendations for vascular access often do not sufficiently consider the uncertainty surrounding the potential benefits of the decision or the cumulative impact of the decision on patient's quality of life. In the evolving health care landscape, it is time for the practice of hemodialysis vascular access to shift from a hierarchical doctor-patient approach to patient-centered care. In this article we review the current state of vascular access practice, present arguments why SDM is necessary in vascular access planning, review barriers and potential solutions to SDM implementation, and discuss future research contingent on an effective system of physician-patient participative decision-making in hemodialysis vascular access practice.

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.