Hemodialysis vascular access in the elderly-getting it right

Research on the development of an intelligent prediction model for blood pressure variability during hemodialysis

OBJECTIVE

Blood pressure fluctuations during dialysis, including intradialytic hypotension (IDH) and intradialytic hypertension (IDHTN), are common complications among patients undergoing maintenance hemodialysis. Early prediction of IDH and IDHTN can help reduce the occurrence of these fluctuations. With the development of artificial intelligence, machine learning and deep learning models have become increasingly sophisticated in the field of hemodialysis. Utilizing machine learning to predict blood pressure fluctuations during dialysis has become a viable predictive method.

METHODS

Our study included data from 67,524 hemodialysis sessions conducted at Ningbo No.2 Hospital and Xiangshan First People's Hospital from August 1, 2019, to September 30, 2023. 47,053 sessions were used for model training and testing, while 20,471 sessions were used for external validation. We collected 45 features, including general information, vital signs, blood routine, blood biochemistry, and other relevant data. Data not meeting the inclusion criteria were excluded, and feature engineering was performed. The definitions of IDH and IDHTN were clarified, and 10 machine learning algorithms were used to build the models. For model development, the dialysis data were randomly split into a training set (80%) and a testing set (20%). To evaluate model performance, six metrics were used: accuracy, precision, recall, F1 score, ROC-AUC, and PR-AUC. Shapley Additive Explanation (SHAP) method was employed to identify eight key features, which were used to develop a clinical application utilizing the Streamlit framework.

RESULTS

Statistical analysis showed that IDH occurred in 56.63% of hemodialysis sessions, while the incidence of IDHTN was 23.53%. Multiple machine learning models (e.g., CatBoost, RF) were developed to predict IDH and IDHTN events. XGBoost performed the best, achieving ROC-AUC scores of 0.89 for both IDH and IDHTN in internal validation, with PR-AUC scores of 0.95 and 0.78, and high accuracy, precision, recall, and F1 scores. The SHAP method identified pre-dialysis systolic blood pressure, BMI, and pre-dialysis mean arterial pressure as the top three important features. It has been translated into a convenient application for use in clinical settings.

CONCLUSION

Using machine learning models to predict IDH and IDHTN during hemodialysis is feasible and provides clinically reliable predictive performance. This can help timely implement interventions during hemodialysis to prevent problems, reduce blood pressure fluctuations during dialysis, and improve patient outcomes.

Personalized decision-making for vascular access creation in hemodialysis

Selecting the appropriate kidney replacement therapy (KRT) is crucial in order to secure optimal care for chronic kidney disease (CKD) patients with end-stage renal disease (ESRD). Next to renal transplantation, the choice of dialysis modality directly affects patient well-being, treatment effectiveness, and long-term outcomes. Therefore, clinical decision-making must take into account a range of factors to tailor decisions to each patient's unique needs. Previously, when the dialysis population was less diverse and resources more limited, straight-forward algorithms could be effectively implemented both for selection of KRT as well as for hemodialysis (HD) vascular access (VA). Recently, the growing ESRD population with more elderly being considered for dialysis care together with improved treatment opportunities have resulted in more challenging decision-making where on-size-fits-all strategies are being replaced by more tailored and personalized strategies aimed to ensure "the right dialysis access - to the right patient - at the right time - for the right reason." In this review, recent trends enforcing a more personalized approach in the selection of VA for HD are summarized and discussed, where these concerns have become especially relevant.

Risk Factor Analysis in Vascular Access Complications for Hemodialysis Patients

Background: Chronic kidney disease (CKD) and renal failure remain critical global health challenges, with vascular access complications posing significant obstacles in hemodialysis management. Methods: This study investigates the early and late complications associated with vascular access procedures in a cohort of 1334 patients from Timiș County Emergency Clinical Hospital. Patients were categorized into early complications, occurring within 30 days postoperatively, and late complications, developing beyond this period. Demographic data, comorbidities, and lifestyle factors, including age, gender, body mass index (BMI), smoking status, hypertension, diabetes, and cardiovascular disease (CVD), were recorded and analyzed. Early complications included thrombosis, hemorrhage, edema, and non-maturation, while late complications involved thrombosis, aneurysmal dilation, venous hypertension, and infections. Results: Hemorrhage (32.3%) and thrombosis (30.8%) were the most prevalent early complications, influenced significantly by diabetes and hypertension. Non-maturation showed a strong association with diabetes and cardiovascular disease (odds ratio: 1.70). For late complications, thrombosis was most frequent, with hypertensive patients exhibiting increased risk (relative risk: 1.18). BMI was a significant factor in both early and late complications. Risk analysis using odds ratios and relative risks revealed distinct patterns of complication risks based on comorbidities and smoking status. Logistic regression modeling for thrombosis demonstrated moderate predictive accuracy (AUC: 0.64). Conclusions: These findings suggest that clinical interventions, such as stricter perioperative glycemic and blood pressure control, and personalized surgical strategies for patients with high BMI or comorbidities, could significantly reduce the incidence of vascular access complications and improve outcomes in this high-risk population.

Preparing a dialysis patient

Preparing a dialysis patient for access placement is a process that should ideally begin well before the need for access use. Unfortunately, this is often not the case and patients are often seen well after dialysis has been initiated with a catheter. The process should include a detail-oriented history and a thorough vascular oriented physical examination. A complete history and physical exam will help tailor access options in individual patients. The KDOQI guideline structures the selection and timing of dialysis access, ensuring each patient's medical circumstances and preferences are taken into account. The preparation of a dialysis patient should also include discussion with the patient in regard to their values and expectations before coming to a life-long plan for the patient. This holistic approach aims to achieve reliable and functioning access while preserving future options and improving patient outcomes. This following review will cover the elements of both as well as adjunctive imaging modalities and their indications to allow for successful access placement.

Comparison of feasibility and effectiveness of tunneled dialysis catheter placement with or without DSA guidance: a propensity score-matched cohort study

BACKGROUND

In some resource-limited regions, the placement of tunneled dialysis catheters (TDC) is often preferred under ultrasound guidance rather than fluoroscopy. This study compared ultrasound-and digital subtraction angiography-guided (DSA)-guided TDC in renal replacement therapy.

METHODS

This retrospective cohort study included all TDC placements performed at our hospital between January 2020 and October 2022. We utilized 1:1 propensity score matching (PSM) to balance the demographic and clinical characteristics of the DSA-guided and ultrasound-guided groups. Dialysis prescriptions and actual dialysis completion were assessed using intraclass correlation coefficients (ICC). Multivariable logistic regression analyses determined the risk factors for early termination of dialysis. The differences in adverse events, catheter function, and catheter tip position were evaluated between the two groups.

RESULTS

The study included 261 patients (142 in the DSA-guided group and 119 in the ultrasound-guided group). After PSM, 91 patients were included in each group, with no significant baseline differences (p > .1). Both groups achieved adequate catheter blood flow and ultrafiltration volumes without deviations from dialysis prescriptions (ICC ≥ 0.75). The DSA-guided group had fewer early dialysis terminations than the ultrasound-guided group (3.3 vs. 12.0%, p = .026). The position of the catheter tip in the right atrium was more consistent in the DSA-guided group (100 vs. 74.2%, p < .001).

CONCLUSION

Hemodialysis catheters inserted under DSA guidance exhibited superior performance compared to those inserted under ultrasound guidance, primarily due to more accurate catheter tip positioning. DSA guidance is recommended when ensuring optimal catheter tip placement.

Novel insights into modifiable risk factors for arteriovenous fistula failure and the importance of CKD lipid profile: A meta-analysis

BACKGROUND

Arteriovenous fistula (AVF) failure can occur in patients undergoing hemodialysis (HD). In this study, we explored the correlation between hyperlipidemia and AVF failure in patients undergoing HD. Moreover, we compared the lipid profiles of patients with chronic kidney disease (CKD) with those of healthy people to provide a basis for lipid-lowering in patients undergoing HD.

METHOD AND ANALYSIS

We searched PubMed, Web of Science, Embase, the Cochrane library, CNKI, CBM, the China Science Periodical Database, and the China Science and Technology Journal Database. The final search was conducted on August 31, 2021, and the search period was restricted between 2000 and August 31, 2021, without publication restrictions. All studies met the inclusion criteria, and the influences of sex, age, geographical location, diagnosis method, and publication year were excluded. The data were analyzed using the random-effects model and the fixed-effects model.

RESULTS

Twenty-eight studies were included in the meta-analysis with 121,666 patients in the CKD group and 1714 patients in the AVF failure group. Triglyceride concentration in patients with CKD was higher than in healthy subjects (MD: -31.56, 95% CI: -41.23 to -21.90, p < 0.00001). A high total cholesterol (TC) concentration (MD: 6.97, 95% CI: 2.19-11.74, p = 0.004) and a high low-density lipoprotein cholesterol (LDL-C) concentration (MD: 23.83, 95% CI: 18.48-29.18, p < 0.00001) were associated with AVF failure. Furthermore, HDL-C was lower in the AVF failure group than in the AVF patency group (MD: -2.68, 95% CI: -4.60 to -0.76, p = 0.006).

CONCLUSION

Our analysis indicates that the AVF failure may be related to the increase of TC/LDL-C and the decrease of HDL-C. Although current guidelines do not consider intensive lipid-lowering therapy as necessary in patients undergoing HD, our research indicates that patients with AVF undergoing HD may need regular TC/LDL-C-lowering therapy to prevent AVF failure. However, this issue still needs well designed prospective trials.

Hemodialysis Vascular Access: A Historical Perspective on Access Promotion, Barriers, and Lessons for the Future

This review describes the history of vascular access for hemodialysis (HD) over the past 8 decades. Reliable, repeatable vascular access for outpatient HD began in the 1960s with the Quinton-Scribner shunt. This was followed by the autologous Brecia-Cimino radial-cephalic arteriovenous fistula (AVF), which dominated HD vascular access for the next 20 years. Delayed referral and the requirement of 1.5-3 months for AVF maturation led to the development of and increasing dependence on synthetic arteriovenous grafts (AVGs) and tunneled central venous catheters, both of which have higher thrombosis and infection risks than AVFs. The use of AVGs and tunneled central venous catheters increased progressively to the point that, in 1997, the first evidence-based clinical practice guidelines for HD vascular access recommended that they only be used if a functioning AVF could not be established. Efforts to promote AVF use in the United States during the past 2 decades doubled their prevalence; however, recent practice guidelines acknowledge that not all patients receiving HD are ideally suited for an AVF. Nonetheless, improved referral for AVF placement before dialysis initiation and improved conversion of failing AVGs to AVFs may increase AVF use among patients in whom they are appropriate.

Is it possible to reach the catheter target proposed by the guidelines? Reasons for catheter use in prevalent hemodialysis patients

INTRODUCTION

Despite the recommendations of the clinical guidelines, the percentage of central venous catheters (CVC) continues to be above the recommended standards. We do not know whether the increasing use of catheters is due to unavoidable or avoidable factors and, in the latter case, it would be in our power to modify these results. The aim of this study was to analyze the causes that condition the use of CVC in a prevalent hemodialysis (HD) population in order to identify those modifiable factors on which to act in order to achieve the objectives of the guidelines.

METHODS

Retrospective, descriptive and observational study in all prevalent patients on chronic hemodialysis belonging to 7 hemodialysis centers in Madrid, Castilla-León and Galicia in a cross-sectional study carried out in June 2021 (637 patients). The following were analyzed: age, sex, nationality, etiology of CKD, the vascular access with which they started hemodialysis, the number of previous failed arteriovenous fistulas (AVF), time since the start of HD, time since the placement of the CVC for the first time, the situation with respect to surgery and the causes of being a CVC carrier. In patients whose cause was refusal to undergo AVF, patients were asked about the cause of the refusal by directed questioning.

RESULTS

Of the 637 patients studied, 255 (40%) had a CVC, 346 had an AVF (54.3%) and 36 (5.7%) had a prosthesis. Of the 255 patients with CVC, 20.4% (52 p) were awaiting vascular access (AVF/prosthesis), 10.2% (26 p) had an AVF but could not be used and 69.4% (177 p) were not considered candidates for surgery (due to vascular surgery (16.9%; 43 pac), nephrology (16.5%, 42 pac) and patient refusal (36%; 92 pac). The most frequent cause for refusal of AVF was fear and patient preference. One of the most important factors associated with CVC use in prevalent patients was having started hemodialysis with a CVC. The greatest use of CVC at the start of HD was significantly associated with having more than one AVF performed, or starting HD urgently and not having been followed up and evaluated in the ACKD consultation.

CONCLUSIONS

There is a high percentage of patients with a central venous catheter due to modifiable causes, which makes it necessary to systematically evaluate the process of creating AVF in order to enhance the planning, creation and maintenance of vascular access from the ACKD clinic, and to achieve the objective of the guidelines.

Factors affecting suboptimal maturation of autogenous arteriovenous fistula in elderly patients with diabetes:A narrative review

Autogenous arteriovenous fistula (AVF) is considered the preferred vascular access choice for individuals undergoing maintenance hemodialysis (MHD) and is widely utilized in China, as reported by the Dialysis Outcomes and Practice Patterns Study. Despite its popularity, the significant incidence of poor AVF maturation often leads to the need for central venous catheter insertion, increasing the risk of complications like superior vena cava stenosis and catheter-related infections, which in turn raises the overall mortality risk. With the prevalence of diabetes rising globally among the elderly and diabetic kidney disease being a leading cause of end-stage renal disease necessitating renal replacement therapy, our retrospective review aims to explore the various factors affecting AVF maturation in this specific patient population. While there have been numerous studies examining AVF complications in MHD patients, including issues like failure, patency loss, stenosis, thrombosis, poor maturation, and other influencing factors, there remains a gap in large-scale clinical studies focusing on the incidence and risk factors for immature AVF specifically in elderly diabetic patients. This paper delves into the pathophysiological mechanisms, diagnostic criteria, and unique considerations surrounding AVF maturation in elderly diabetic patients, distinguishing them from the general population. Our literature review reveals that elderly diabetic patients exhibit a higher risk of AVF immaturity compared to the general population. Additionally, there exists a continuing discourse regarding several aspects related to this group, including the choice of dialysis access, timing of AVF surgery, and surgical site selection. Furthermore, we delve into the management strategies for vascular access within this specific group with the goal of providing evidence-based guidance for the establishment and maintenance of functional vascular access in elderly diabetic patients.

A meta-analysis of vascular access outcomes in hemodialysis patients aged 75 years or older

BACKGROUND

Several existing guidelines advocate the access creation without any specific recommendations for those patients over 75 years of age. The aim of this meta-analysis is to compare the outcomes of different vascular access procedures in the sub-group of elderly ESRD patients ⩾75 years of age.

METHODS

A literature search was performed using the MEDLINE and SCOPUS electronic databases. The analysis focused on studies with subgroups of elderly patients ⩾75 years of age with different vascular access procedures, and compared the failure rates of autologous versus prosthetic vascular access. Articles comparing patency rates of distal (forearm) versus proximal upper arm AVFs were also investigated.

RESULTS

Twelve relevant studies were identified and included in the meta-analysis. The pooled results revealed a statistically significant unassisted (primary) failure rate at 24 months in favor of autologous AVFs [odds ratio (OR): 0.56, 95% CI: 0.38-0.83, p = 0.003]. A secondary analysis revealed significantly higher 12 months unassisted (primary) and secondary failure rates of forearm AVFs compared with proximal upper arm AVFs (OR: 2.14, 95% CI: 1.53-2.97, p < 0.00001 and OR: 1.76, 95% CI: 1.12-2.78, p < 0.01 respectively).

CONCLUSION

An increased risk of failure of prosthetic vascular access procedures was found compared with autologous AVFs in patients ⩾75 years of age. Elderly patients ⩾75 years should not be excluded from creation of an autologous access, with proximal upper arm AVFs having better patency rates.

Frailty screening for determination of hemodialysis access placement

OBJECTIVE

Choosing the right hemodialysis vascular access for frail patients remains difficult because the patient's preferences and the likelihood of access function and survival must be considered. We hypothesize that patients identified before arteriovenous (AV) access as frail by the PRISMA-7 score may have worse outcomes, indicating that fistula creation may not be the most clinically beneficial option and it would be in the best interest of the patient to receive either AV graft (AVG) placement or dialysis through a percutaneous catheter. Our pilot study aims to determine whether an association exists between patient frailty as defined by PRISMA-7 and newly created AV fistula (AVF) and AVG access outcomes.

METHODS

This was a single institutional prospective cohort study of patients undergoing new AVF or AVG intervention from April 2021 to May 2023. Patients were assessed using the PRISMA-7 frailty questionnaire before their AV access surgery. Patients were grouped by frailty score and score groups were examined for trends. Univariable analysis was performed for baseline differences between frail and nonfrail patients. Failure to achieve maturation, postoperative infection, and 180-day mortality difference was also investigated for frail vs nonfrail patients. Univariable analysis was performed for nonmaturation using standard comorbidities, arterial and venous diameters, and frailty. Multivariable binary logistic regression was performed for the outcome of nonmaturation using frailty as one of the variables in conjunction with the univariable risks associated with nonmaturation.

RESULTS

A total of 40 patients undergoing new AV access placement were investigated, among whom 53% were designated as frail (PRISMA-7 score ≥3). When comparing the frail and nonfrail new AV access groups, the access (AVF and AVG combined) failed in 48% (10/21) of the frail patients, but only failed in 5% (1/19) of the nonfrail patients 1 (P = .012). When distinguishing between AV access types, AVF creations followed the overall trend with 60% of AVF access (9/15) sites in frail patients failing to mature when compared with nonfrail patients, who all had fistulas that matured to use (P = .049). Surgical site infection was absent in all frail patients and present in 5% of nonfrail patients (1/19). Both 30-day and 60-day readmission rates were higher in the frail group compared with the nonfrail group. There was 180-day mortality present in 5 of frail patients % (1/21) and absent in nonfrail patients. Multivariable analysis revealed that both frailty (adjusted odd ratio, 10.19; 95% confidence interval, 1.20-82.25); P = .033) and younger age (adjusted odd ratio, 0.953; 95% confidence interval, 0.923-0.983; P = .002) both had a significant association with nonmaturation. Power analysis revealed a power statistic of 0.898 indicating a probability of type 2 error of 10.02% with a P value of .002. Hosmer-Lemeshow goodness of fit for the logistic regression had 75% overall accuracy for the model.

CONCLUSIONS

Patient frailty is significantly associated with an increased incidence of AV access failure to mature.

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.

Hemodialysis vascular access in elderly patients: A comprehensive review

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of outcomes with permanent vascular access in an elderly Korean population based on the National Health Insurance Service database

INTRODUCTION

As nearly half of patients with end-stage kidney disease (ESKD) who initiate hemodialysis (HD) are over 65 years old (commonly defined as elderly), the fistula first strategy is controversial even in HD patients ≥65 years.

METHODS

In Korea's National Health Insurance Service database from 2008 to 2019, 41,989 elderly (≥ 65 years) HD patients were retrospectively reviewed to identify their clinical characteristics and outcomes. Vascular access (VA) patencies, risk factors associated with patencies and patient survival between arteriovenous fistula (AVF) and arteriovenous graft (AVG) were compared.

RESULTS

Elderly AVF group (n = 28,467) had superior primary, primary assisted, and secondary patencies than elderly AVG group (n = 13,522) (all p values are <0.001). Patient survival was also better in the elderly AVF group than in the elderly AVG (p < 0.001). In multivariate Cox regression analyses for diverse outcomes, AVG (vs. AVF) was identified as a risk factor for all-cause mortality (adjusted hazard ratio [HR]: 1.307; 95% confidence interval [CI]: 1.272-1.343; p < 0.001), primary patency (adjusted HR: 1.745; 95% CI: 1.701-1.790; p < 0.001), primary-assisted patency (adjusted HR: 2.163; 95% CI: 2.095-2.233; p < 0.001), and secondary patency (adjusted HR: 3.718; 95% CI: 3.533-3.913; p < 0.001).

CONCLUSION

Our study demonstrated that as a permanent VA for HD, AVF should be strongly considered in elderly (≥ 65 years) ESKD Korean patients. The age limit for AVF creation in ESKD patients should be adjusted more upward.

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.

Health insurance provider and endovascular treatment availability are associated with different hemodialysis vascular access profiles: A Brazilian national survey

In Brazil, most hemodialysis (HD) patients are treated by the country's public health system. However, accessibility to healthcare is different for public and private patients. This study aimed to identify the profile of vascular access in a Brazilian HD sample. Additionally, it aimed to examine the influence of public and private health insurance, accessibility to endovascular treatments, and timely arteriovenous access creation on the prevalence of tunneled catheters (TCs), non-tunneled catheters (NTCs), and arteriovenous (AV) access. We conducted a cross-sectional electronic survey across 834 centers. Centers were inquired about the number of patients with public and private health insurance, the profiles of vascular access, time for AV access creation, accessibility to TC insertion and endovascular treatments, and the availability of peritoneal dialysis and kidney transplantation. Logistic regression and multilevel logistic regression were performed to evaluate possible interactions between the independent variables. A total of 7,973 patients across 47 HD centers were included in the survey. Public health patients accounted for 77% of the study sample. The overall vascular access profiles of the public and private insurance groups were significantly different (p < 0.001). For patients with public health insurance, the prevalence of any catheter was 25%, while that for private patients was 31.8% (p < 0.001). The prevalence of TCs was more common in private patients (15.3% vs. 23.1%, p < 0.001). AV accesses were more common in public health patients (75% vs. 68.2%, p < 0.001), as were fistulas (72.4% vs. 63.1%, p < 0.001). AV grafts were more prevalent among patients with private insurance (2.6 vs. 5.1%, p < 0.001). The availability of endovascular treatments increased the chance of having a TC by 2.3-fold (OR = 2.33, 95% CI = 1.30-4.18); however, it did not reduce the chance of having any catheter. A high chance of having a catheter was found when the time to AV access creation exceeded 60 days. The differences between public and private patients may be explained by underpayments and the decreased accessibility to care infrastructure in the public system, especially for endovascular treatments. In this sample, public health patients had a decreased risk of having a TC over an NTC. Differences in care accessibility and insurance type might influence the type of vascular access.

Clinical and ultrasound evaluation for hemodialysis access creation

Chronic kidney disease (CKD) is an emerging global burden with an increasing number of patient's requiring renal replacement therapy (RRT), with hemodialysis being the most prevalent dialysis modality. A functioning vascular access remains the main constrain for an adequate treatment. Clinical and, in some patients, ultrasound evaluation are fundamental for better access planning. Access planning is dependent not only on patient clinical characteristics and preference but also in vascular patrimony. As such, ultrasound evaluation aids in characterizing patient arterial and venous upper arm anatomy and provides information for which access would better suit each patient. Doctors dealing with CKD patients should be familiar with the role of ultrasound and Doppler use in access planning.

Early cannulation arteriovenous graft (Acuseal) versus standard arteriovenous graft in patients with end-stage renal disease

INTRODUCTION

The use of Acuseal arteriovenous graft (AAVG) is spreading in end-stage renal disease (ESRD) patients for its advantages in early cannulation. However, comparison of clinical outcomes between AAVGs and standard arteriovenous grafts (SAVGs) is limited. In this study, we compared the performance of AAVGs and SAVGs.

METHODS

Consecutive ESRD patients underwent prosthetic vascular access between October 2017 and May 2019 at a single center were identified. Patients were divided into AAVG group and SAVG group. Patients' demographics, perioperative characteristics, and clinical outcomes were collected. Primary, primary assisted, and secondary patency rates were compared using Kaplan-Meier analyses. Postsurgery complications were compared using chi-square test or the Fisher's exact test.

FINDINGS

A total of 304 arteriovenous grafts (AVGs) were implanted in 145 males and 159 females (mean age, 60.1 years; range, 20-91 years), comprising 143 AAVGs and 161 SAVGs. Median time to first cannulation was 3 days (interquartile range [IQR], 1-15 days) in the AAVG group and 30 days (IQR, 20-52 days) in the SAVG group (P < 0.001). Adjusted primary, primary assisted, and secondary patency at 12 months were not significant different between AAVGs and SAVGs (P = 0.911, P = 0.945, and P = 0.640, respectively). There was no statistical significance in regards to thrombosis (AAVG, 34.3%; SAVG, 26.1%; P = 0.120) and infection (AAVG, 4.9%; SAVG, 2.5%; P = 0.261) between the groups.

DISCUSSION

Acuseal grafts provide comparable patency, and complication rates to SAVGs, with less time to first cannulation from the graft implanted.

Is home hemodialysis a practical option for older people?

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

Comparing outcomes of tunnelled dialysis catheter insertions and exchanges with or without fluoroscopy

BACKGROUND/OBJECTIVE

To study the safety and outcome profiles of tunnelled dialysis catheter (TDC) insertions and exchanges with fluoroscopy versus without fluoroscopy.

METHODS

This was a retrospective cohort study of all TDC insertions or exchanges performed at our centre, between January 2017 and December 2017. Patient demographics, laboratory results and catheter placement information were obtained from electronic records. Immediate technical success, early and late catheter associated complications were collected. Outcomes for TDC inserted with or without fluoroscopy were statistically analysed.

RESULTS

A total of 351 TDC insertions and 253 TDC exchanges were performed. Out of 351 TDC insertions, 261 were done with fluoroscopy while 90 were done without. Out of 253 TDC exchanges, 219 were done with fluoroscopy while 34 were done without. For both TDC insertions and exchanges, there were no significant differences in complication rates when done with or without fluoroscopy. Mean duration of catheter patency was longer for TDC inserted without fluoroscopy, after adjusting for site of insertion and presence of previous TDC.

CONCLUSIONS

The technique of inserting TDC in the right internal jugular vein (IJV) without fluoroscopy is a safe and effective method in selected patients. This supports the practice of performing the procedure without fluoroscopy, especially in institutions where fluoroscopy facilities are not readily available. This potentially translates into reduced healthcare resources and hospitalisation days, which is particularly valuable in times of limited resources such as the current Coronavirus Disease 2019 (COVID-19) pandemic.

Clinical and ultrasound evaluation for hemodialysis access creation

Chronic kidney disease (CKD) is an emerging global burden with an increasing number of patient's requiring renal replacement therapy (RRT), with hemodialysis being the most prevalent dialysis modality. A functioning vascular access remains the main constrain for an adequate treatment. Clinical and, in some patients, ultrasound evaluation are fundamental for better access planning. Access planning is dependent not only on patient clinical characteristics and preference but also in vascular patrimony. As such, ultrasound evaluation aids in characterizing patient arterial and venous upper arm anatomy and provides information for which access would better suit each patient. Doctors dealing with CKD patients should be familiar with the role of ultrasound and Doppler use in access planning.

Outcomes of arteriovenous fistula in elderly patients on maintenance haemodialysis

BACKGROUND

The optimal vascular access strategy in elderly patients receiving haemodialysis (HD) remains controversial. We aim to report the outcomes of arteriovenous fistula (AVF) in elderly patients initiated on maintenance HD in our centre.

METHODS

Medical records of 688 incident patients initiated on HD from 2010 to 2012 in a tertiary centre were retrospectively reviewed. Patients' characteristics and AVF outcomes were compared among those < 65 years (non-elderly), ≥ 65-75 years (early elderly) and ≥ 75 years (late elderly).

RESULTS

There were 418 non-elderly, 184 early elderly and 86 late elderly patients. There is a higher proportion of brachiocephalic and brachiobasilic fistula created in the late elderly (24.9% vs. 37.0% vs. 41.8%, p = 0.001). The outcomes of accesses created were comparable in the 3 age groups with similar proportions of functional AVFs (80.4% vs. 79.3% vs. 75.6%, p = 0.832) and comparable 1-, 3- and 5-year primary and secondary patency rates (p = 0.351 and 0.282, respectively). However, a longer maturation time (2.78 vs. 2.86 vs. 3.72 months, p = 0.010) and a higher mean number of interventions to assist maturation of the first AVF were required in late elderly patients (0.19 vs. 0.22 vs. 0.35, p = 0.014). Following AVF creation, median patient survival in the non-elderly, early and late elderly was 65.2 vs. 55.1 vs. 49.8 months respectively.

CONCLUSION

AVFs created in elderly patients have comparable outcomes compared to non-elderly patients although more interventions are required to assist maturation with a longer maturation time necessitating early access creation to allow for time needed due to maturation delay.

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

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

The survival analysis of tunnel-cuffed central venous catheter versus arteriovenous hemodialysis access among elderly patients: A retrospective single center study

BACKGROUND

There is currently a controversy for the optimal vascular access option in the elderly, regarding their multiple comorbidities and life expectancies. Our study aimed to compare the survival of tunneled cuff venous catheter (CVC) and arteriovenous access (AV access) in elderly patients.

METHODS

A retrospective cohort study was performed by electronic medical record review. All hemodialysis patients aged 65 years and over who firstly initiated dialysis from January 1, 2012 to December 31, 2016 at Siriraj hospital, Thailand, were included. The primary outcomes are to compare a 2-year period of survival between CVC and AV access in terms of abandonment, death, and combined outcome. Propensity score covariate and Charlson Comorbidity Score (CCI) were used for multivariable analysis adjustment.

RESULTS

A total of 359 patients were included; 216 (60.2%) patients had initiated hemodialysis via CVC while the rest used AV access. The patients' average ages were 76.7 ± 7.0 and 74.0 ± 5.8 years (p-value<0.001) in the CVC and AV access group, respectively. The 2-year mortality rates of CVC and AV access groups were 24.1% and 15.4%, respectively (p-value = 0.038). Multivariable analyses showed that the adjusted hazard ratio (aHR) of combined endpoints, i.e., vascular access abandonment and death, was statistically different only in the CCI-adjusted model (aHR = 0.68, 95% CI: 0.46-0.99). Mortality from infection cause was more common in the CVC group than the AV access group.

CONCLUSION

CVC access maybe considers an alternative option for frail elderly patients. However, the patient selection is a crucial issue, given higher infection-related mortality in patients using CVC.

The patient experience of hemodialysis vascular access decision-making

BACKGROUND

To describe vascular access (VA)-related decision-making from the patient perspective, in patients who have already chosen hemodialysis as their renal replacement modality, and identify areas where physicians can improve this experience.

METHODS

In-person, semi-structured interviews with 15 patients with end-stage kidney disease were systematically analyzed by two independent researchers using thematic analysis. Interviews were conducted until systematic analysis revealed no new themes.

RESULTS

Patients had mean age 57 (range 22-85), with seven males and diverse racial/ethnic/marital status. All (15/15) patients viewed VA as "intertwined and interrelated" with dialysis, prioritized the dialysis, described the VA merely as the "hookup" to life-preserving dialysis and gave it minimal consideration. Three themes were identified: consolidation of dialysis and VA, reliance on supportive advisors and communication with physicians. Although 14/15 patients described processes common to medical decision-making, including information seeking, learning from the experiences of others, and weighing risks and benefits, they did not apply these processes specifically to VA. While all participants took ownership of the VA decision, they lacked clear understanding about the different types of VA and their consequences. Most patients (14/15) depended on family and friends for reinforcement, motivation and advice. Patients all described physician characteristics they associated with trustworthiness, the most common being listening and explaining, demonstrating empathy and making an effort to meet the patient's individual needs. Perceived arrogance, unavailability and lack of expertise represented untrustworthiness. The majority (14/15) accepted VA recommendations from physicians they found trustworthy and authoritative.

CONCLUSIONS

The study participants were minimally engaged in VA decision-making. Educational aids and shared decision-making tools are needed to empower patients to make better-informed, self-efficacious VA decisions.

Comparison of vascular access patency and patient survival between native arteriovenous fistula and synthetic arteriovenous graft according to age group

INTRODUCTION

Arteriovenous fistula (AVF) is historically known to be the ideal option for vascular access (VA) for hemodialysis compared with arteriovenous graft (AVG). However, this approach has been recently questioned in the aging population because of their poor vessel quality and multiple comorbidities.

METHODS

Data from a total of 2200 patients from the VA category of The Catholic Medical Center nephrology registry from March 2009 to February 2017 were analyzed. We compared VA patency and patient survival between two groups, AVF and AVG, according to age.

FINDINGS

Compared with the AVG group, survival benefit in the AVF group continued even in patients ≥80 years. In the whole population, all the primary patency (PP), primary-assisted patency (PAP), and secondary patency (SP) measures were superior in the AVF group. With regard to subgroups, PP was comparable between the two groups in patients ≥65 years, whereas PAP and SP were superior in the AVF group even in septuagenarian patients who are from 70 to 79 years old. In patients ≥80 years, all the patency measures were comparable between the two groups. When the separate comparison of lower-arm AVF (or upper-arm AVF) and AVG, lower-arm AVF failed to demonstrate its superiority in any kind of patency in septuagenarian patients compared with AVG, whereas upper-arm AVF demonstrated its superiority in PAP and SP in septuagenarian patients. However, even upper-arm AVF failed to demonstrate its superiority in any kind of patency in patients ≥80 years.

DISCUSSION

Arteriovenous fistula if using upper-arm vessel showed the superior VA patency up to septuagenarian patients, whereas, in HD patients ≥80 years, AVF and AVG were comparable in VA patency.

Perspectives in Individualizing Solutions for Dialysis Access

The vascular access is the lifeline for the hemodialysis patient. Previous national vascular access guidelines have emphasized placement of arteriovenous fistulas in most hemodialysis patients. However, the new Kidney Disease Outcomes Quality Initiative guidelines for vascular access, soon to be published, will focus on a patient's end-stage kidney disease "life plan" and take a patient "first" approach. One of the major themes of the new Kidney Disease Outcomes Quality Initiative guidelines is selecting the "right access, for the right patient, at the right time, for the right reason". Given the availability of new advances in biomedical technologies, techniques, and devices in the vascular access field, this shift to a more patient-centered vascular access approach presents unique opportunities to individualize the solutions and care for patients requiring a dialysis vascular access. This review article will address 3 potential areas where there is an unmet need to individualize solutions for dialysis vascular access care: (1) biological approaches to improve vascular access selection and selection of therapies, (2) vascular access care for the post-transplant patient, and (3) vascular access disparities in race, gender, and the elderly patient.

Listening to music during arteriovenous fistula surgery alleviates anxiety: A randomized single-blind clinical trial

BACKGROUND

Both end-stage renal disease and being wait-listed for a kidney transplant are anxiety-causing situations. Wait-listed patients usually require arteriovenous fistula surgery for dialysis access. This procedure is performed under local anesthesia. We investigated the effects of music on the anxiety, perceived pain and satisfaction levels of patients who underwent fistula surgery.

AIM

To investigate the effect of music therapy on anxiety levels and perceived pain of patients undergoing fistula surgery.

METHODS

Patients who were on a waiting list for kidney transplants and scheduled for fistula surgery were randomized to control and music groups. The music group patients listened to music throughout the fistula surgery. The State-Trait Anxiety Inventory was performed to assess anxiety, additionally visual analog scale was used to evaluate perceived pain, willingness to repeat the procedure and patient satisfaction. Demographic features, comorbidities, surgical history, basic surgical data (location of fistula creation, duration of surgery, incision length) and intra-operative hemodynamic parameters were recorded by an investigator blinded to the study group. An additional trait anxiety assessment was performed following the surgery.

RESULTS

There was a total of 55 patients included in the study. However, 14 patients did not fulfill the criteria due to requirement of sedation during surgery or uncompleted questionnaires. The remaining 41 patients were included in the analysis. There were 26 males and 15 females. The control and music groups consisted of 20 and 21 patients, respectively. With regard to basic surgical and demographic data, there was no difference between the groups. Overall patient satisfaction was significantly higher and intra-operative heart rate and blood pressure were significantly lower in the music group (P < 0.05). Postoperative state anxiety levels were significantly lower in the music group.

CONCLUSION

Music therapy can be a complimentary treatment for patients undergoing fistula surgery. It can reduce anxiety and perceived pain, improve intraoperative hemodynamic parameters and enhance treatment satisfaction, thus may contribute to better compliance of the patients.

The Impact of Comorbidity Burden on The Association between Vascular Access Type and Clinical Outcomes among Elderly Patients Undergoing Hemodialysis

The optimal vascular access type for elderly hemodialysis patients is controversial. We evaluated the impact of comorbidity burden on the association between vascular access type and mortality risk among 23,100 hemodialysis patients aged ≥65 years from the Korean Society of Nephrology End-Stage Renal Disease registry data. Subjects were stratified into tertiles according to the simplified Charlson comorbidity index (sCCI), and the survival and hospitalization rates were compared with respect to vascular access type: arteriovenous fistula (AVF), arteriovenous graft (AVG), and central venous catheter (CVC). Among all tertiles of sCCI, CVC use showed highest risk of mortality than AVF use. In the lowest to middle tertile, no difference was observed in survival rates between the use of AVF and AVG. However, in the highest tertile, AVG use showed higher risk of mortality than AVF use. When subjects were classified according to a combination of sCCI tertile and access type (AVF vs. AVG), patients with the highest CCI with AVG showed 1.75-folded increased risk of mortality than those with the lowest sCCI with AVF. Hospitalization rates due to access malfunction were highest in patients with CVC in all sCCI tertiles. In the highest tertile, patients with AVG showed increased rates of hospitalization compared to those with AVF due to access malfunction. However, hospitalization rates due to access infection were highest in patients with AVG in all tertiles. The use of AVF may be of benefit and switching to AVF should be considered in elderly hemodialysis patients with a high burden of comorbidity.

Outcomes of vascular access in hemodialysis patients: Analysis based on the Korean National Health Insurance Database from 2008 to 2016

Background

Controversies exist whether arteriovenous fistula (AVF) placement is preferred over arteriovenous graft (AVG) for elderly patients. Current guidelines did not offer specific recommendations. Thus, this study was conducted to analyze the all-cause mortality and primary patency associated with various vascular access (VA) types according to age group.

Methods

This retrospective observational study investigated the Korean insurance claims data of chronic kidney disease patients who began hemodialysis between January 2008 and December 2016. We investigated all-cause mortality associated with initial VA in incident hemodialysis patients and primary patency between AVF and AVG according to age group.

Results

The proportion of patients with a tunneled dialysis catheter (TDC) that was first placed for VA increased from 18.4% in 2008 to 52.3% in 2016. Incident hemodialysis patients with a TDC or AVG for the initial VA had significantly higher mortality risk than patients with an AVF, except for patients over 85 years, who showed no significant difference in all-cause mortality regardless of VA type. In the patency analysis on initial AV access, AVG had significantly poorer primary patency than AVF in all age groups.

Conclusion

AVF had better patency than AVG in all age groups; however, the benefit of AVF attenuated in the older age groups. The mortality rate between AVF and AVG was not significantly different in patients over 85 years. Therefore, a “patient-first” approach should be emphasized over a “fistula-first” approach in AV access creation for incident hemodialysis patients older than 85 years.

Maturing arteriovenous accesses in incident haemodialysis patients and first-year outcomes

INTRODUCTION

Nephrologists have increased arteriovenous access placement in patients with chronic kidney disease. Not yet usable 'maturing' arteriovenous fistulas and grafts are nearly as common as mature arteriovenous fistulas or grafts. Little has been reported about patients initiating haemodialysis with unready arteriovenous fistulas or grafts.

METHODS

The United States Renal Data System records for all adult patients initiating haemodialysis with central venous catheters between July 2010 and December 2011. Patients were categorized by whether a maturing arteriovenous fistula or graft was present. Transition to working arteriovenous fistula or graft was determined from linked Medicare claims. Modality changes and survival were ascertained. A logistic model for one-year survival and a subdistribution hazards model for transition to working arteriovenous fistula or graft, accounting for the competing risk of death, were constructed.

RESULTS

Compared to central venous catheter-only, maturing arteriovenous fistula or graft was associated with access conversion (hazard ratio = 2.23 (2.17-2.30) and 3.25 (2.97-3.56), respectively, p < 0.001 for both). Median time to conversion, among those who transitioned, was 95 days (interquartile range = 56-139) for patients with a maturing arteriovenous graft and 135 days (98-198) with a maturing arteriovenous fistula, versus 193 days (138-256) with central venous catheter-only. Pre-dialysis nephrology care, male sex and non-Caucasian race were associated with access conversion. Patients without a maturing arteriovenous fistula or graft had decreased odds of one-year survival (odds ratio = 0.61 (0.58-0.66), p < 0.001), which attenuated with adjustment for access conversion (adjusted odds ratio = 1.06 (0.98-1.13), p = 0.2).

CONCLUSION

Maturing arteriovenous fistulas or grafts were associated with enhanced first-year survival and increased opportunity for working arteriovenous fistulas or grafts, which may reflect pre-dialysis decision-making, quality of care and comorbid diseases. Central venous catheter exposure was substantial, even among patients with maturing access. Contributory factors prolonging conversion to arteriovenous access need to be identified and addressed.

Beyond the Technical: Determining Real Indications for Vascular Access and Hemodialysis Initiation in End-Stage Renal Disease

Determining valid indications for vascular access creation and hemodialysis initiation in end-stage renal disease requires utilization of verified prognostication tools and recognition of triggers to initiate serious conversations, and implementation of concurrent palliative care and/or hospice care is recommended. Establishment of a multi-disciplinary team that includes consideration of interventionalists in the pre-dialysis medical situation is important. A "catheter best" approach may be the most appropriate for some patients to meet goals of care.