Arteriovenous Graft Use Research Articles

Current status and prospects of clinical practice for arteriovenous graft in China

The use of arteriovenous graft (AVG) fails to meet the clinical needs in China, although it is recommended by guidelines to be the alternative access for maintenance hemodialysis (MHD) patients. Patency and complication incidence of AVG reported by recent research is superior to traditional cognition, and thus AVG should be one of main types of access in our country. Personalized selection of proper patients and grafts may improve the outcomes of AVG. In the future, outcomes of AVG must be further improved by clinical research with accurate personalized selection, basic research of precise molecule target and innovation of graft materials.

Factors influencing primary patency time of percutaneous transluminal balloon angioplasty for hemodialysis arteriovenous grafts

Objective: To investigate the factors affecting primary patency time in arteriovenous graft (AVG) patients receiving percutaneous transluminal balloon angioplasty (PTA). Methods: Hemodialysis patients who underwent AVG placement at the First Affiliated Hospital of Chongqing Medical University between February 2018 and December 2021 were included. The factors including age, gender, total duration of AVG use, site of stenosis, degree of stenosis, length of stenosis, residual stenosis, and presence of thrombosis were analyzed, and influencing factors of primary patency time in AVG were determined using a multiple linear regression model. Results: A total of 101 patients who underwent 331 PTA treatments were enrolled, including 35 males and 66 females. The median age of patients undergoing PTA for the first time was 61 (51, 68) years, and the primary patency time after PTA was 5 (3, 10) months. The patients were followed up for (38.5±15.3) months. Multivariable linear regression analysis revealed that severe stenosis at the venous anastomosis and reflux veins (β=-2.773, 95%CI:-5.440--0.105, P=0.042), female (β=-2.247, 95%CI:-3.853--0.642, P=0.006), and previous multiple PTA treatments (β=-0.516, 95%CI:-0.978--0.054, P=0.029) were risk factors for a shorter primary patency time after PTA. Conclusion: Severity of stenosis at the venous anastomosis and reflux veins of the AVG, female, and a history of multiple previous PTA treatments are associated with a shorter primary patency time in AVG patients.

#2598 Risk of vascular access complications in haemodialysis patients initiating dialysis with arteriovenous fistula or arteriovenous graft

Abstract Background and Aims Patients (pts) with end-stage kidney disease (ESKD) rely on successful vascular access (VA) for continual hemodialysis (HD) treatments. Possible VA complications are numerous and complex, which makes them difficult to study. We developed a comprehensive VA complication metric to evaluate VA complications holistically. The goal of this analysis was to describe the risk of having high VA complications in in-center hemodialysis (ICHD) pts whose initial VA included arteriovenous fistula (AVF) or arteriovenous graft (AVG), and who have been successfully receiving regular dialysis care for at least 2 years. Method Adult ICHD pts, with Charlson Comorbidity Index <8, who initiated treatment at one of the clinics of a large dialysis organization between Jan 2016 and Dec 2021, received continuous treatment for ≥2 years, remained on ICHD until censored, and whose initial VA included an AVF or an AVG were investigated. Pts could be censored by death, transplant, discharge from FKC, or study end. Initial VA was determined by use of either AVF or AVG during ICHD treatments in the 90-120 days after initiation of ICHD. Individual-level vascular access complication rates (VACR) were defined as the sum of a patient's VA complication events divided by their duration of follow-up until censor date. VA complication events include: hospitalization due to VA problems or VA infection, VA infections not requiring hospitalization, VA removal due to infection, symptoms of VA infection, symptoms of thrombosis/stenosis, documented stenosis, documented thrombosis, cannulation issues, bacteremia, sepsis. The threshold for high VACR was the highest quintile values. Logistic regression was used to determine the risk of having a high VACR by demographic and comorbid conditions. Results Analyses included 94,208 pts who met our inclusion criteria. The mean VACR for the population was 2.7 VA complications per patient per year (PPY). Pts whose VACR was in the highest quintile, ≥4.34 PPY, were categorized as having high VACR. Table 1 shows the risk of having high VACR by demographic characteristics and comorbid conditions present at ICHD initiation. In general, we observed lower or neutral risk of having high VACR in the demographic characteristics we examined. However, older patients as well as patients with higher BMI had an increase in risk of having high VACR. We observed significant increased risk of having high VACR in diabetic pts (20%), pts with cerebrovascular disease (35%), pts with COPD (10%), pts with Congestive Heart Failure (21%), patients with dementia (22%), and patients with history of myocardial infarction (26%). Conclusion We observed that being older, having increased BMI, or having several comorbid conditions are associated with increased risk of having high VACR in successful ICHD patients who initiated dialysis with an AVF or AVG. Multivariate analyses to further explore these associations are warranted.

"Outcomes of arteriovenous fistulae cannulation in the first 6 weeks of use: A retrospective multicenter observational study".

Arteriovenous fistula (AVF) management for haemodialysis (HD) is one of the most challenging aspects of clinical care. A successful cannulation outcome when an AVF or arteriovenous graft (AVG) is used for the first time can be influenced by many factors, including access maturity, staff skill, and patient factors. This study examined AVF/AVG outcomes at initiation of HD across two major metropolitan public hospitals. Electronic medical records were reviewed to collect data retrospectively for a cohort of all newly commencing ESRD HD starts during 2018 to identify cannulation outcomes in the first 6 weeks. Of the 117 patients included, AVG use was low (5%). Twenty-four percent of patients required a surgical intervention to salvage a poorly functioning AVF prior to commencing HD. About 32.5% of the cohort had an uneventful start with all successful cannulations. For the remainder of the cohort the number of treatments with unsuccessful cannulation ranged from 1 to 4 or more. About 36% required a surgical intervention for a poorly functioning AVF after commencing HD. Commencing HD with a CVC is associated with a lower likelihood of subsequent successful cannulation (p < 0.001). Even in experienced centres, a subset of patients experienced complicated cannulation in the first 6 weeks of HD. Several areas of improvement could be considered for these patients; timely referral for access creation, post-operative surveillance to ensure AVF maturation inclusive of duplex ultrasonography, gentle induction using small gauge needles and low blood flows, and consideration of a single needle HD initiation pathway.

MO015HAEMODIALYSIS VASCULAR ACCESS THROMBOSIS: AN ANALYSIS OF EVENTS FROM THE PROACTIVE IV IRON THERAPY IN HAEMODIALYSIS PATIENTS (PIVOTAL) TRIAL

Abstract Background and Aims Haemodialysis vascular access thrombosis (VAT) is a common occurrence that undermines the safe and effective delivery of haemodialysis (HD) and has been associated with anaemia therapy. In the Proactive IV Iron Therapy in Haemodialysis Patients trial (PIVOTAL), proactive high-dose intravenous iron dosing was compared with reactive low-dose intravenous iron dosing. VAT was a pre-specified secondary endpoint. Here we present data detailing the VAT events in PIVOTAL, alongside univariate and multivariate analyses of risk association, testing the hypothesis that VAT may be independently associated with a proactive iron dosing regimen. Method In PIVOTAL 2141 adults with end-stage kidney disease within 12 months of initiating regular HD were randomised 1:1 to either high-dose intravenous iron administered proactively, or low-dose intravenous iron administered reactively, on the basis of monthly Ferritin and Transferrin saturation levels. Erythropoiesis Stimulating Agents were dosed sufficiently to maintain a haemoglobin of 100 to 120g/L. Vascular access use was recorded at baseline and on a monthly basis. VAT was regarded as a safety event with investigators mandated to record such events. VAT was defined clinically, with investigators expected to report thrombotic occlusion of the access (either arteriovenous or catheter thrombosis) significant enough to prevent further effective use without intervention. Baseline demographic, blood pressure and laboratory data underwent univariate analysis with regard to first event of VAT. Primary patient demographics (age, gender, primary renal disease, randomised treatment arm) were put forward for inclusion in a multivariable cox proportional hazards model alongside variables that associated on univariate testing with α&amp;lt;0.05. Analyses were performed using SAS software, version 9.4 (SAS Institute). Results 2141 eligible patients were randomised, of whom 877/2141 (41.0%) were using a central venous catheter (CVC), 1209/2141 (56.5%) an arteriovenous fistula (AVF), and 55/2141 (2.6%) an arteriovenous graft (AVG) at baseline. Over a median follow up of 2.1 years, 480/2141 (22.4%) experienced a VAT event; 194/887 (21.9%) of CVC patients; 263/1209 (21.8%) of AVF patients; and 23/55 (41.8%) of AVG patients. On univariate testing VAT events associated with diabetes as a cause of kidney failure (HR 1.44, 95%CI 1.19 to 1.74, p&amp;lt;0.001), AVG use at baseline (HR 2.37, p&amp;lt;0.001), digoxin use (HR 2.35, p=0.002), and diuretic use (HR 1.24, p=0.02). Angiotensin receptor blocker (ARB) use associated with less VAT (HR 0.66, p=0.013), as did male gender (HR 0.74, p=0.002), and never having smoked (HR 0.68, p=0.008). No association was seen with age, AVF use, CVC use, blood pressure, history of cardiovascular (CV) disease, atrial fibrillation, other CV medications, C-reactive protein, haemoglobin, transferrin saturation, ferritin or randomised treatment group (Proactive 262/1093 (24.0%) v Reactive 218/1048 (20.8%), HR 1.15, p=0.12) . Multivariate analysis found diabetes as a cause of kidney failure (HR 1.45, p&amp;lt;0.001), AVG use (HR 2.29, p&amp;lt;0.001), digoxin exposure (HR 2.48, p&amp;lt;0.001) and diuretic exposure (HR 1.25, p=0.018) to independently associate with VAT. Male gender (HR 0.75, p=0.002), never smoked (HR 0.68, p=0.004) and ARB use (HR 0.66, p=0.011) were found to independently associate with lower risk of VAT. Investigation of interaction between significant predictors found diuretic use in AVF patients to reach nominal significance (p=0.033). No other significant interactions being demonstrated. Conclusion In PIVOTAL, VAT affected nearly one quarter of the cohort over a median of 2.1 years. Diabetes as a cause of kidney failure, active smoking, AVG use, female gender, exposure to digoxin, and exposure to diuretic were independently associated with VAT, but this was not the case with higher iron dosing. ARB use was independently associated with lower risk.

P1318EPIDEMIOLOGY OF BLOODSTREAM INFECTIONS IN A SCOTTISH HAEMODIALYSIS POPULATION WITH FOCUS ON VASCULAR ACCESS METHOD

Abstract Background and Aims Haemodialysis (HD) vascular access infections account for approximately 28% of infection-associated hospitalisations in patients with end-stage renal disease1. Traditionally there has been focus on Staphylococcus aureus (S. aureus) infections, however there is increasing recognition of the burden of Gram-negative bloodstream infection (BSI) in the HD population2,3. Epidemiological analysis has enabled surveillance of the impact of antimicrobial protocols on BSI rate and outcome2. Scottish Registry data reflects that access methods are changing alongside the HD population phenotype, with increasing use of arterio-venous graft (AVG) and central venous catheters for incident and prevalent HD access3. In this study, the rate of BSI in a contemporary Scottish HD cohort is reported by microbial species and vascular access type: arterio-venous fistula (AVF), AVG, tunnelled central venous catheter (TCVC) or non-tunnelled central venous catheter (NTCVC). Method The Strathclyde Electronic Renal Patient Record (SERPR) database for the West of Scotland was utilised to obtain retrospective observational data all adult patients attending inpatient and outpatient renal services across seven dialysis units between 1st January 2017 and 31st December 2017. All BSIs were analysed as separate episodes if more than 14 days apart, regardless of the suspected source of infection, and expressed as events per 1000 HD days. The number of days each patient was exposed to each vascular access subtype was calculated utilising the prospectively recorded HD access observations. Prevalent HD vascular access type was noted for each BSI. Results There were 786 patients who underwent HD with 217 503 total HD days over the study period. A total of 147 separate BSIs occurred, involving 115 patients. A total of 168 organisms were encountered in these BSIs. There were 49 BSIs during 126, 674 HD days using AVF access, 14 BSIs during 25, 511 AVG HD days, 81 BSIs during 64, 353 TCVC HD days and 3 BSIs during 965 NTCVC HD days. Table 1 outlines the BSI rates by vascular access and organisms identified Staphylococci-related BSI comprised the majority of events (51.7%), with S. aureus implicated in 47% of these BSIs. Coagulase-negative staphylococci were the most commonly identified organisms in the AVF, TCVC and NTCVC groups, with S. aureus the leading organism in the AVG group. Gram-negative organisms accounted for the next largest proportion of BSIs (27%) and were more prevalent in the TCVC and NTCVC groups. Conclusion AVF access subtype was associated with the lowest BSI rate, and NTCVC the highest which is in keeping with previous studies and one of the drivers for AVF as the preferred HD access type internationally. Staphylococci continue to represent a large proportion of BSIs in this cohort, however other organisms are prevalent. BSIs caused by Gram-negative organisms and Candida species were represented more heavily in the TCVC and NTCVC population, perhaps representing co-morbidity of these groups.

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.

Costs Attributable to Arteriovenous Fistula and Arteriovenous Graft Placements in Hemodialysis Patients with Medicare coverage

Introduction: Hemodialysis (HD) in end-stage renal disease (ESRD) patients requires vascular access (VA) through an arteriovenous fistula (AVF), a prosthetic arteriovenous graft (AVG), or a central venous catheter. While AVF or AVG is commonly used for HD, the economic implications of AVF versus AVG use have not been fully established. We describe the healthcare resource utilization and costs of AVF and AVG use for incident ESRD patients in the United States. Methods: This observational cohort study of AVF and AVG placements used data from the United States Renal Data System to identify and follow access placements. AVF and AVG placements after ESRD onset for incident patients from 2012 to 2014 with continuous Medicare primary coverage were included. All-cause and access-related Medicare costs were averaged over the placement lifetime and expressed as per dialysis-month costs. Results: The analysis included 38,035 AVF placements and 12,789 AVG placements. Total all-cause monthly costs for AVF averaged USD 8,508; mean monthly costs were USD 3,027 for inpatient (IP), USD 3,139 for outpatient (OP), USD 1,572 for physician services, and USD 770 for other care settings. Access-related monthly costs averaged USD 1,699 and represented 20% of all-cause charges for AVFs. Mean all-cause monthly costs for AVG were USD 9,605; by setting monthly costs were USD 3,811 for IP, USD 3,034 for OP, USD 1,881 for physician services and USD 879 for other care settings. Access-related monthly costs averaged USD 2,656 and represented 28% of all-cause charges for AVGs. Discussion/Conclusions: This study indicates that costs due to VA are a significant burden on Medicare budgets and on patients. The factors driving access-related utilization and costs merit attention in future research. Both optimizing process of care and discovery innovation may significantly accelerate better stewardship of available healthcare resources.

Assessment of Use of Arteriovenous Graft vs Arteriovenous Fistula for First-time Permanent Hemodialysis Access

Initial hemodialysis access with arteriovenous fistula (AVF) is associated with superior clinical outcomes compared with arteriovenous graft (AVG) and should be the procedure of choice whenever possible. To address the national underuse of AVF in the United States, the Centers for Medicare & Medicaid has established an AVF goal of 66% or greater in 2009. To explore contemporary practice patterns and physician characteristics associated with high AVG use compared with AVF use. This review of 100% Medicare Carrier claims between January 1, 2016, and December 31, 2017, includes both inpatient and outpatient Medicare claims data. All patients undergoing initial permanent hemodialysis access placement with an AVF or AVG were included. All surgeons performing more than 10 hemodialysis access procedures during the study period were analyzed. Placement of an AVF or AVG for initial permanent hemodialysis access. A surgeon-level AVG (vs AVF) use rate was calculated for all included surgeons. Hierarchical logistic regression modeling was used to identify patient-level and surgeon-level factors associated with AVG use. A total of 85 320 patients (median age, 70 [range, 18-103] years; 47 370 men [55.5%]) underwent first-time hemodialysis access placement, of whom 66 489 (77.9%) had an AVF and 18 831 (22.1%) had an AVG. Among the 2397 surgeons who performed more than 10 procedures per year, the median surgeon level AVG use rate was 18.2% (range, 0.0%-96.4%). However, 498 surgeons (20.8%) had an AVG use rate greater than 34%. After accounting for patient characteristics, surgeon factors that were independently associated with AVG use included more than 30 years of clinical practice (vs 21-30 years; odds ratio, 0.85 [95% CI, 0.75-0.96]), metropolitan setting (odds ratio, 1.25 [95% CI, 1.02-1.54]), and vascular surgery specialty (vs general surgery; odds ratio, 0.77 [95% CI, 0.69-0.86]). Surgeons in the Northeast region had the lowest rate of AVG use (vs the South; odds ratio, 0.83 [95% CI, 0.73-0.96]). First-time hemodialysis access benchmarking reports for individual surgeons were created for potential distribution. In this study, one-fifth of surgeons had an AVG use rate above the recommended best practices guideline of 34%. Although some of these differences may be explained by patient referral practices, sharing benchmarked performance data with surgeons could be an actionable step in achieving more high-value care in hemodialysis access surgery.

Risk factors affecting arteriovenous access patency in nocturnal home hemodialysis patients .

Intensive hemodialysis is associated with more frequent arteriovenous (AV) access complications. We performed a retrospective cohort study to ascertain potential risk factors associated with access dysfunction in a cohort of nocturnal home hemodialysis (HHD) patients. Consecutive patients undergoing HHD from October 1999 to November 2015 using an AV access were included. Patient demographics and clinical variables were collected. Primary outcome was defined as any access dysfunction including thrombosis, stenosis, or intervention. Frequent dysfunction was defined as > 2 events per access year. Factors associated with access dysfunction and abandonment were studied using logistic regression and Cox regression analysis, respectively. 189 patients were included. 62.4% were male, and 77.2% had an AV fistula. The median duration of follow-up was 60.3 months. 105 patients (56%) had access dysfunction, resulting in an incidence of 66.2 events per 100 access years. History of renal transplant (OR 0.44, 95% CI 0.22-0.91), the use of AV graft (OR 9.23, 95% CI 3.41-25.00), and vintage of AV access (OR 1.01 per month, 95% CI 1.00-1.02) were significant predictors of access dysfunction. Patients with AV grafts (OR 7.11, 95% CI 2.71-18.69) and history of access dysfunction prior to HHD (OR 4.51, 95% CI 1.65-12.34) had more frequent dysfunction. AV accesses appear to have a finite duration of functionality, with history of renal transplant being a protective factor, and more dysfunction was found in AV grafts. Access-related factors account for frequent dysfunction rather than patient or HHD factors. The role of access surveillance, especially in patients having high risk of dysfunction, remains to be investigated. .

Current state of dialysis treatment and vascular access management in Japan.

According to the data from the Japanese Society for Dialysis Therapy, the number of dialysis patients was about 330,000 at the end of 2016. The mean age of newly initiated patients was 69.4 years and that of maintenance was 68.2 years. And, diabetic nephropathy is the most common primary disease, with an incidence rate of 43.2%. These results mean that the systemic vascular condition is getting worse. In spite of these backgrounds, the patients of 97.3% were treated by hemodialysis; therefore, careful management of vascular access is essential to better maintain the condition of patients. The Dialysis Outcomes and Practice Patterns Study shows that vascular access modalities are an important factor in determining prognoses of patients and that prognosis in Japan is one of the best worldwide. In Japan, the use of arteriovenous fistulae accounts for 95% of vascular access modalities. However, a statistic by Japanese Society for Dialysis Therapy suggests that the use of arteriovenous graft has been increasing. In 2005, Japanese Society for Dialysis Therapy Guidelines recommended percutaneous transluminal angioplasty be the first choice for the treatment of vascular access stenosis. Since then, percutaneous transluminal angioplasty has become an important procedure for long-term maintenance of the morphology and function of vascular access. In Japan, approximately 60% of percutaneous transluminal angioplasty are conducted by nephrologists and urologists; in addition, arteriovenous fistulae creation procedures are also performed by them. According to my private opinion, such conditions above show that even in the absence of standardized training on vascular access management, doctors on site perform their duties in an appropriate manner. However, the problems of how we evaluate the specificity in Japan and pass it down the generations still remain.

Outcomes of Hemodialysis Vascular Access in Patients Initiating Dialysis With a Tunneled Catheter

The objective of this study was to determine factors that influence time to removal of tunneled hemodialysis catheter (THC), probability of repeated vascular access creation, and time to repeated vascular access. The Optum (Eden Prairie, Minn) Clinformatics database, which contains claims from a large managed care organization, from 2011 to 2016 was queried for patients who initiated hemodialysis with a THC. Time from initial arteriovenous fistula (AVF) or arteriovenous graft (AVG) to THC removal and time to repeated AVF or AVG were analyzed using Cox proportional hazards. Multivariate models included age, sex, race, diabetes, cardiac arrhythmia, congestive heart failure, peripheral vascular disease, and obesity as covariates. There were 8355 vascular accesses that met the inclusion criteria 6648 (77%) AVFs and 1940 (23%) AVGs. Median follow-up was 424 days (range, 1-2097 days). Patients undergoing AVF were younger and more likely to be male and white (Table). At 90 days, 20.3% (95% confidence interval [CI], 19.3%-20.3%) of AVFs vs 56% (95% CI, 53.7%-58.4%) of AVGs had the THC removed. At 180 days, 56.7% (95% CI, 55.4%-58.1%) of AVFs vs 68.4% (95% CI, 66.1%-70.6%) of AVGs had the THC removed. By day 315, 74% of patients with both AVFs and AVGs had the THC removed. Multivariate analysis demonstrated a significant interaction between vascular access type and age ≥70 years (P < .001). In the age group <70 years, patients who underwent AVG had a THC removal rate 46% higher than that of patients who underwent AVF. In the age group ≥70 years, patients who underwent AVG had a THC removal rate 88% higher than that of patients who underwent AVF. There were 1982 (23.7%) patients who underwent a second vascular access. Multivariate analysis demonstrated that AVG vs AVF (odds ratio, 0.70; 95% CI, 0.61-0.81) and age ≥70 years vs <70 years (odds ratio, 0.87; 95% CI, 0.78-0.98) were associated with a lower odds of second access. In patients who underwent a second access, multivariate analysis demonstrated that initial AVG was associated with longer time to second access (hazard ratio, 0.60; 95% CI, 0.54-0.68). Creation of AVG vs AVF significantly decreased the time to THC removal in dialysis-dependent patients, with a larger difference in patients aged ≥70 years vs <70 years. Initial AVG was associated with lower odds of second access and longer time to second access in those who underwent second access. These results contradict the dictum of “fistula first” and support the judicious use of AVG in achieving the more recent shift toward “catheter last.”TableDemographics by access typeFistula (n = 6486), No. (%)Graft (n = 1869), No. (%)P valueAge, years mean (SD)66.2 (13)69 (12)<.001Age ≥70 years2979 (46)1028 (55)<.001Male3920 (60)811 (44)<.001Race<.001 Asian216 (3)51 (3) Black1586 (24)677 (36) Hispanic859 (13)192 (10) White3663 (56)915 (49) Unknown168 (3)28 (1)Diabetes5257 (81)1565 (84).001Cardiac arrhythmia4688 (72)1400 (75).13Congestive heart failure5021 (77)1480 (79).073Peripheral vascular disease4406 (68)1322 (71).011Obesity2596 (40)694 (37).03SD, Standard deviation. Open table in a new tab

Association of early loss of primary functional patency of arteriovenous access with mortality in incident hemodialysis patients: A nationwide population-based observational study.

The long-term survival and life quality of hemodialysis (HD) patients depend on adequacy of dialysis via a well-functioning vascular access. Loss of primary functional patency (PFP) of an arteriovenous access (AVA) eventually happens in HD patients. The association between time to loss of PFP of AVAs and mortality in HD patients remains unclear. The retrospective nationwide population-based cohort study compared the hazards of mortality with time to loss of PFP. We enrolled 1618 adult incident HD patients who received HD via AVAs for at least 90 days between January 1, 2001 and December 31, 2013. They were divided into early (≤1 year) and late (>1 year) loss of PFP according to intervention-free intervals (time from first successful cannulation to percutaneous transluminal angioplasty [PTA]). Patients with early loss of PFP were older; had more clinic visits annually and higher Charlson comorbidity index scores; were associated with higher proportions of diabetes mellitus, coronary artery disease, heart failure, stroke, chronic obstructive pulmonary disease, cancer, and use of arteriovenous graft, diuretic, antidiabetic drugs, and aspirin (all P < .05). Kaplan-Meier analysis revealed the cumulative incidence of mortality was significantly higher in patients with early loss of PFP (log-rank test; P < .01). After adjustment, early loss of PFP was independently associated with a higher risk of mortality (adjusted hazard ratio, 1.21; 95% confidence interval, 1.01-1.45; P = .045). Regarding the impact of time to PTA on mortality, patients with intervention-free intervals of ≤3, 3 to 6, and 6 to 12 months had similar trends of lower survival. Early loss of PFP is an independent risk factor for mortality in chronic HD patients. A comprehensive strategy for maintaining PFP and reducing dysfunctional AVAs may be required.

Arteriovenous Fistula Maturation in Prevalent Hemodialysis Patients in the United States: A National Study

Arteriovenous fistulas (AVFs) are the preferred form of hemodialysis vascular access, but maturation failures occur frequently, often resulting in prolonged catheter use. We sought to characterize AVF maturation in a national sample of prevalent hemodialysis patients in the United States. Nonconcurrent observational cohort study. Prevalent hemodialysis patients having had at least 1 new AVF placed during 2013, as identified using Medicare claims data in the US Renal Data System. Demographics, geographic location, dialysis vintage, comorbid conditions. Successful maturation following placement defined by subsequent use identified using monthly CROWNWeb data. AVF maturation rates were compared across strata of predictors. Patients were followed up until the earliest evidence of death, AVF maturation, or the end of2014. In the study period, 45,087 new AVFs were placed in 39,820 prevalent hemodialysis patients. No evidence of use was identified for 36.2% of AVFs. Only 54.7% of AVFs were used within 4 months of placement, with maturation rates varying considerably across end-stage renal disease (ESRD) networks. Older age was associated with lower AVF maturation rates. Female sex, black race, some comorbid conditions (cardiovascular disease, peripheral artery disease, diabetes, needing assistance, or institutionalized status), dialysis vintage longer than 1 year, and catheter or arteriovenous graft use at ESRD incidence were also associated with lower rates of successful AVF maturation. In contrast, hypertension and prior AVF placement at ESRD incidence were associated with higher rates of successful AVF maturation. This study relies on administrative data, with monthly recording of access use. We identified numerous associations between AVF maturation and patient-level factors in a recent national sample of US hemodialysis patients. After accounting for these patient factors, we observed substantial differences in AVF maturation across some ESRD networks, indicating a need for additional study of the provider, practice, and regional factors that explain AVF maturation.

Principles of treating enlarging pseudoaneurysm in a dialysis arteriovenous graft

The arteriovenous graft (AVG) is one of the major types of permanent vascular access used to provide hemodialysis. Complications encountered with AVG use include stenosis, infection, thrombosis, and pseudoaneurysm formation. Venous outflow stenosis along with frequent needle cannulation at the same site can lead to breakdown of the graft material, resulting in pseudoaneurysm formation. In the following case, we illustrate common management principles used to treat pseudoaneurysms. While stent-grafts have been utilized for pseudoaneurysm repair, stent-graft usage is not always optimal. Surgical management may be an ideal choice of treatment. The role of educating the dialysis staff and patients is essential to identify and minimize the risk of pseudoaneurysm formation.

A Single-Institution Study of Permanent Vascular Access Outcomes in Patients undergoing Hemodialysis

BackgroundVascular access (VA) is essential for successful hemodialysis (HD) but its provision poses significant challenges to renal services. This study aimed to report the long-term outcomes for different types of first permanent VA, and identify factors that affected outcomes in a cohort of patients undergoing HD at a single renal unit. MethodsData recorded before April 1, 2013, were collected on factors related to patient characteristics and VA management. Univariate analysis of VA survival was undertaken using the Kaplan-Meier method with log-rank testing used to test for differences between subgroups. Secondary outcomes included VA complication and intervention rates. ResultsOf those first permanent VA attempts (n = 103), 26.2% were radiocephalic arteriovenous fistulae (RCAVF), 54.4% were brachiocephalic arteriovenous fistulae (BCAVF), 10.7% were transposed basilic arteriovenous fistulae (TBAVF), and the remaining 8.7% were polytetrafluoroethylene forearm loop arteriovenous grafts (AVG). Overall cumulative secondary VA survival rates at 6, 12, and 24 months were 90.9%, 82.8%, and 73.4%, respectively. Complication rates for RCAVF, BCAVF, TBAVF, and AVG were 0.5, 1.2, 4.5, and 2.6 per patient year on HD, respectively. Intervention rates for RCAVF, BCAVF, TBAVF, and AVG were 0.4, 0.8, 2.9, and 2.1 per patient year on HD, respectively. A primary renal diagnosis of diabetes (P = 0.022), use of temporary central venous catheter (P = 0.003) or rope-ladder needling (P = 0.013), and the use of TBAVF or AVG (P < 0.001) were predictive of significantly poorer VA survival. ConclusionsRCAVF and BCAVF were associated with significantly superior outcomes compared with TBAVF and AVG in terms of complication and intervention rates, and long-term survival.

Dialysis Access Anatomy and Interventions: A Primer.

The creation of arteriovenous fistulae and the use of arteriovenous grafts are a vital component in the treatment of patients undergoing dialysis. For many patients in this population, these accesses represent the permanent solution to their dialysis needs. Understanding the basic anatomy of the most common accesses used, as well as initial treatment of many underlying causes of access failure is vital for any interventionalist performing such procedures. This article outlines the most common approaches to surgically placed accesses used for renal replacement therapy, as well as the basics of interventional approaches used to treat the most common abnormalities causing their dysfunction.

New hybrid procedures in treating occluded arteriovenous hemodialysis grafts.

The use of arteriovenous graft is indicated in patients if the subcutaneous venous bed is exhausted or unsuitable for arteriovenous fistula creation. The leading cause of failure of a prosthetic arteriovenous hemodialysis-access graft is venous anastomotic stenosis causing thrombosis of the graft. A number of surgical techniques and endovascular tools have been used to treat this stenosis and thrombosis. None have yet proven to be ideal. This study was designed to evaluate the results of hybrid treatment of arteriovenous graft thrombosis associated with venous anastomotic stenosis. Over the period 2013-2014, we treated 16 AVG occlusions. Immediately after the diagnosis of occlusion was made, the patients underwent thrombectomy using a Fogarty catheter. After thrombectomy, a diagnostic fistulogram was performed and if VAG stenosis was confirmed, it was treated with balloon angioplasty and stent graft introduction. Lesions were dilated to reduce the stenosis in the treated area to less than 25%. Primary patency after 12 months was 32.8%. Primary assisted patency was 44.7%, secondary patency was 47.6%. Restenosis of the stent graft was seen in two patients. Recurring AVG occlusion was observed in four patients. The average number of interventions to maintain AVG patency was 1.18 per patient/1 year of dialysis. Treatment of AVG thrombosis due to VAG stenosis by hybrid procedure proved to be effective and improved secondary patency.

Vascular access for long-term hemodialysis/hemodiafiltration patients.

We investigated the characteristics of patients who received long-term hemodialysis/hemodiafiltration (HD/HDF) treatment for over 30 years at our group of hospitals and type of vascular access (VA) used. As of August 2014, 950 patients were receiving HD/HDF treatment at one of our hospitals. Of those, we investigated 41 (4.3%) undergoing long-term treatment in regard to their characteristics and VA type. The items subjected to analysis were sex, primary illness, age at time of dialysis initiation, present age, duration (years) of HD/HDF, type of arteriovenous fistula (AVF) and arteriovenous graft (AVG), history of surgery and AVF persistence rate. The subjects consisted of 22 men and 19 women, and their mean HD/HDF duration was 33.4 ± 2.8 years. For primary illness, the majority (n = 31) had chronic glomerulonephritis. The age at time of dialysis initiation was 31.7 ± 7.76 years and present age was 64.5 ± 7.65 years. They had received 3.8 VA surgeries. For present VA type, 23 patients (56.0%) had an AVF and 13 (31.7%) an AVG, while 4 AVF patients (9.7%) had a history of AVG use. One patient (2.4%) had a superficialized artery. The mean HD/HDF duration of the 13 AVG patients was 7 years and the longest was 18 years. AVF persistence rate estimated by the Kaplan-Meier method was 75% at 30 years after dialysis initiation. The present results suggest that the ratio of patients with AVG increased with prolonged HD/HDF treatment. AVG has a higher probability of complications and lower patency as compared to AVF, thus careful management is needed. On the other hand, AVG contributes more to a good long prognosis, as it offers efficient dialysis. In cases of vascular deterioration due to long-term hemodialysis, it is inevitable to change from AVF to AVG, thus the ratio of AVG patients is expected to increase in cases of long-term HD/HDF.

Patients started on hemodialysis with tunneled dialysis catheter have similar survival after arteriovenous fistula and arteriovenous graft creation

Current guidelines suggest that arteriovenous fistula (AVF) is associated with survival advantage over arteriovenous graft (AVG). However, AVFs often require months to become functional, increasing tunneled dialysis catheter (TDC) use, which can erode the benefit of an AVF. We sought to compare survival in patients with end-stage renal disease after creation of an AVF or AVG in patients starting hemodialysis (HD) with a TDC and to identify patient populations that may benefit from preferential use of AVG over AVF. Using U.S. Renal Data System databases, we identified incident HD patients in 2005 through 2008 and observed them through 2008. Initial access type and clinical variables including albumin levels were assessed using U.S. Renal Data System data collection forms. Attempts at AVF and AVG creation in patients who started HD through a TDC were identified by Current Procedural Terminology codes. We accounted for the effect of changes in access type by truncating follow-up when an additional AVF or AVG was performed. Survival curves were then constructed, and log-rank tests were used for pairwise survival comparisons, stratified by age. Multivariate analysis was performed with Cox proportional hazards regressions; variables were chosen using stepwise elimination. An interaction of access type and albumin level was detected, and Cox models using differing thresholds for albumin level were constructed. The primary outcome was survival. Among the 138,245 patients who started with a TDC and had complete records amenable for analysis, 22.8% underwent AVF creation (mean age ± standard deviation, 68.9 ± 12.5 years; 27.8% mortality at 1 year) and 7.6% underwent AVG placement (70.2 ± 12.0 years; 28.2% mortality) within 3 months of HD initiation; 69.6% remained with a TDC (63.2 ± 15.4 years; 33.8% mortality). In adjusted Cox proportional hazards regression, AVF creation is equivalent to AVG placement in terms of survival (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.93-1.02; P = .349). AVG placement is superior to continued TDC use (HR, 1.54; 95% CI, 1.48-1.61; P < .001). In patients older than 80 years with albumin levels >4.0 g/dL, AVF creation is associated with higher mortality hazard compared with AVG creation (HR, 1.22; 95% CI, 1.04-1.43; P = .013). For patients who start HD through a TDC, placement of an AVF and AVG is associated with similar mortality hazard. Further study is necessary to determine the ideal access for patients in whom the survival advantage of an AVF over an AVG is uncertain.