Arteriovenous Graft Placement Research Articles

Surgical and endovascular assisted maturation procedures improve cannulation after arteriovenous fistula creation, but not after arteriovenous graft placement.

After creation, arteriovenous fistulae (AVF) and arteriovenous grafts (AVG) can undergo surgical or endovascular assisted maturation (AM) procedures to enable use for hemodialysis. We sought to explore the association of interventions with successful two-needle cannulation (TNC) using the United States Renal Data System (USRDS). Using the 2012-2017 USRDS, we identified patients initiating hemodialysis with tunneled dialysis catheters (TDC). Successful AVF/G use was defined as two-needle cannulation (TNC). Our principal outcome was time to first TNC after AVF/G creation. Death and new access placement were competing events that precluded TNC. Competing-risks regression models were constructed to identify factors associated with cannulation. Logistic regression was used to assess the association between AM procedures and 1-year TNC and also to compare post-cannulation outcomes. Among 81,143 patients, 15,880 (19.6%) had AVG and 65,263 (80.4%) had AVF. AVG patients were more likely than AVF patients to achieve TNC at 1 year on unadjusted (77.4% vs 64.0%, p < 0.001) and on multivariate analysis (sHR = 2.56 (2.49-2.63), p < 0.001). For AVFs, one AM surgical procedure was associated with improved 1-year TNC rates, but further revisions were not helpful. Endovascular AM procedures were associated with increased AVF TNC rates. Any procedure, surgical or endovascular, was detrimental to achieving TNC for AVGs.Following initial TNC, those accesses that needed AM procedures were associated with higher rates of access failure (AVF: OR = 1.32 (1.21-1.45); AVG: OR = 1.77 (1.500-2.00); p < 0.001), catheter replacement (AVF: OR = 1.27 (1.20-1.34); AVG: OR = 1.56 (1.42-1.71), p < 0.001), and additional endovascular procedures (AVF: 0.75 ± 1.22 no AM vs 1.33 ± 1.62 any AM; AVG: 1.31 ± 1.77 no AM vs 1.96 ± 2.22 any AM; all p < 0.001). AVG achieved TNC after creation more reliably than AVF. A single surgery or endovascular procedures for AVFs is associated with greater rates of TNC. For AVGs, any AM procedure is associated with lower cannulation rates, and reinforces the need for careful operative technique.

Comparison of Lower and Upper Extremity Arteriovenous Graft: A Retrospective Clinical Analysis with 5-Year Follow-Up

For patients in whom an upper extremity (UE) vascular access cannot be established, the lower extremity (LE) arteriovenous graft (AVG) could be selected. However, the application of LE AVG is limited owing to its high infection rate, uncertain patency time, and technical difficulties. This study aimed to compare the long-term patency rates and the incidence of vascular access complications of AVG in the LE and UE to provide a reference for the applications of AVG, especially in the LEs. This was a retrospective analysis of patients who successfully underwent LE or UE AVG placement from March 2016 to October 2021. Patient characteristics were collected and compared using parameter or nonparameter tests according to data type. Postoperative patency was evaluated using Kaplan-Meier test. Postoperative complication incidence density and intergroup comparison were estimated using the Poisson distribution. Twenty-two patients with LE AVG and 120 patients with UE AVG were included. The 1-year primary patency rate was 67.4% (±11.0% standard error [SE]) in the LE group and 30.1% (±4.5% SE) in the UE group (P=0.031). The assisted primary patency rate at postoperative months 12, 24, and 36 was respectively 78.6% (±9.6% SE), 65.5% (±14.4% SE), and 49.1% (±17.8% SE) in the LE group and 63.3% (±4.6% SE), 47.5% (±5.4% SE), and 30.4% (±6.1% SE) in the UE group (P=0.137). The secondary patency rate at postoperative months 12, 24, and 36 remains 95.5% (±4.4% SE) in the LE group and 89.3% (±2.9% SE), 83.7% (±3.9% SE), and 73.0% (±6.2% SE), respectively, in the UE group (P=0.200). Postoperative complications included stenosis, occlusion/thrombosis, infection, steal syndrome, pseudoaneurysm, severe postoperative serum swelling, and AVG exposure. The total incidence rates of postoperative complications were 0.87 (95% confidence interval [CI] 0.59-1.23) versus 1.61 (95% CI 1.45-1.79) (P=0.001) cases/person-year, the incidence rates of stenosis were 0.45 (95% CI 0.26-0.73) versus 0.92 (95% CI 0.80-1.06) (P=0.005) cases/person-year and the incidence rates of occlusion/thrombosis were 0.34 (95% CI 0.17-0.59) versus 0.62 (95% CI 0.52-0.74) cases/person-year in the LE group compared to those in the UE group (P=0.041). LE AVG had higher primary patency rate and lower postoperative complication incidence than UE AVG. With the development of interventional technology, both LE AVG and UE AVG exhibited high secondary patency rates. LE AVG can be a reliable and long-term alternative for appropriately selected patients with unusable UE vessels.

Is There a Bias Against Those With a Disability Status? Arteriovenous Graft Outcomes in a VA Access Population

Patients with end-stage renal disease on chronic hemodialysis often face socioeconomic challenges. The Veterans Health Administration supports those on disability with regular follow-ups. This study aimed to investigate the associations between disability and arteriovenous graft (AVG) placement outcomes in a veteran patient population. All veteran patients who had primary AVG placement (January 1, 2006, to January 1, 2019) were reviewed. Patient factors collected included disability status, patient demographics, comorbidities, medication use, smoking status, prior precursors, and history of previous central venous access. AVG outcomes examined included successful cannulation, days rested, functional patency, total endovascular interventions, and thrombosis events. Statistical tests used included the Fisher exact test and Student t-tests. A total of 88 patients had an AVG placed, and 69% of patients were on disability with a mean age of 64.9 ± 10.7 years. There was no statistical difference in race, body mass index, comorbidities, antiplatelet, or anticoagulation. Patients with disability were found to have a statistically higher percentage of prior hemodialysis access arteriovenous fistula (63.9% vs 37%; P = .02) when compared with the nondisabled patient cohort. Patients with disability were found to have statistically longer days rested (65.8 ± 132.6 vs 33.5 ± 35.5 days; P = .03), higher thrombosis events (1.7 ± 2.1 vs 0.6 ± 0.7; P = .001), and total number of endovascular interventions (3.2 ± 4.3 vs 1.2 ± 1.8; P = .004). When case matching to control for prior hemodialysis access history, a statistically significantly higher mean number of days rested (P = .001) and thrombosis events (P = .03) were found in the disability cohort (Table). Disability status is associated with increased access days rested, total endovascular interventions, and thrombosis events. Our data imply that patients with disabilities might have increased underlying comorbid states driving access outcomes. In addition, such status in the VA system might indicate an increased bias toward intervention and possible delay in access utilization.TableHemodialysis access outcome differences between those undergoing primary arteriovenous graft placement (AVG) without and with an established disability statusNo disability (n = 27)Disability (n = 61)P valueSuccessful cannulation, No. (%)20 (74.1)51 (83.6).29aRested (mean days ± SD)33 ± 3666 ± 132.03bFunctional patency (mean days ± SD)417 ± 533706 ± 519.61bEndovascular interventions (mean ± SD)1.2 ± 1.83.2 ± 4.3.004bThrombosis events (mean ± SD)0.6 ± 0.71.7 ± 2.1.001bSD, Standard deviation.aFactors were analyzed using the Fisher exact test.bFactors were analyzed using the Student t-test. Open table in a new tab

Comparing post-maturation outcomes of arteriovenous grafts and fistulae.

Though arteriovenous grafts (AVG) mature more reliably than arteriovenous fistulae (AVF) and require fewer maturation procedures (MP) to obtain functional patency, AVG are thought to have worse function after maturation. We explored differences in post-maturation outcomes between the following groups: AVF patients who did (AS-AVF) and did not (unAS-AVF) require assisted maturation and AVG patients who did (AS-AVG) and did not (unAS-AVG) require assisted maturation. Using the US Renal Data System (2012-2017), we retrospectively identified patients who initiated dialysis with a central venous catheter, underwent AVF or AVG placement and achieved successful two-needle cannulation. Primary patency and access abandonment after maturation were compared across groups using competing risks regression methods, generating sub-hazards ratios (sHR). We identified 42,664 AVF and 12,335 AVG that met inclusion criteria. A larger proportion of AVFs required interventions: 18,408 AVF (43.2%) versus 2594 AVG (21.0%; p < 0.01). Both AS-AVG and AS-AVF patients experienced patency loss at 1 year more frequently compared with unAS-AVG (67.5% & 57.5% vs 55.2% respectively). Patency loss was lowest in unAS-AVF (38.9%). These trends were robust on adjusted analysis (unAS-AVG reference, AS-AVG sHR = 1.44, p < 0.01; AS-AVF sHR = 1.08, p < 0.01, unAS-AVF sHR = 0.67, p < 0.01). AS-AVGs were more likely to be abandoned than unAS-AVGs (11.7% unAS-AVG vs 17.2% AS-AVG). Fistulae, assisted or not, had lower unadjusted rates of 1-year abandonment than grafts (8.9% AS-AVF vs 7.3% unAS-AVF). On adjusted analysis, AVF usage was protective against abandonment (unAS-AVG, reference; AS-AVF sHR = 0.67, p < 0.01; unAS-AVF sHR = 0.59, p < 0.01) while AS-AVG was not (AS-AVG sHR = 1.32, p < 0.01). unAS-AVF have the best long-term outcomes. AS-AVF lose primary patency at a higher rate than unAS-AVG. AVGs may be a better choice than AVFs if veins are marginal and likely to require assisted maturation. Further research is needed to identify anatomic and physiologic factors that affect long-term performance and influence conduit choice.

Arteriovenous Graft Failure in the Veterans Health Administration: Outcome Disparities Associated with Race.

Background Vascular access for ongoing hemodialysis often fails, frequently requiring repeated procedures to maintain vascular patency. While research has shown racial discrepancies in multiple aspects of renal failure treatment, there is poor understanding of how these factors might relate to vascular access maintenance procedures after arteriovenous graft (AVG) placement. Purpose To evaluate racial disparities associated with premature vascular access failure after percutaneous access maintenance procedures following AVG placement using a retrospective national cohort from the Veterans Health Administration (VHA). Materials and Methods All hemodialysis vascular maintenance procedures performed at VHA hospitals between October 2016 and March 2020 were identified. To ensure the sample represented patients who consistently used the VHA, patients without AVG placement within 5 years of their first maintenance procedure were excluded. Access failure was defined as a repeat access maintenance procedure or as hemodialysis catheter placement occurring 1-30 days after the index procedure. Multivariable logistic regression analyses were performed to calculate prevalence ratios (PRs) measuring the association between hemodialysis maintenance failure and African American race compared with all other races. Models controlled for vascular access history, patient socioeconomic status, and procedure and facility characteristics. Results In total, 1950 access maintenance procedures in 995 patients (mean age, 69 years ± 9 [SD], 1870 men) with an AVG created in one of 61 VHA facilities were identified. Most procedures involved African American patients (1169 of 1950, 60%) and patients residing in the South (1002 of 1950, 51%). Premature access failure occurred in 215 of 1950 (11%) procedures. When compared with all other races, African American race was associated with premature access site failure (PR, 1.4; 95% CI: 1.07, 1.43; P = .02). Among the 1057 procedures in 30 facilities with interventional radiology resident training programs, there was no evidence of racial disparity in the outcome (PR, 1.1; P = .63). Conclusion African American race was associated with higher risk-adjusted rates of premature arteriovenous graft failure after dialysis maintenance. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Forman and Davis in this issue.

Intimal growth on the luminal surface of arteriovenous grafts in rats.

Endothelial cells are known to grow on the luminal surface of arteriovenous grafts (AVGs) used in hemodialysis. Although endothelial cells are important for preventing infection, a detailed growth of endothelial cells in AVGs is unknown. This study sought to create a simpler animal model of AVGs and to investigate how endothelial cells form on the luminal surface. Polyethylene grafts were placed between the cervical artery and vein of Wistar rats. The grafts were removed at 6h, 24h, 3days, or 7days after placement. The luminal surface was observed under optical and polarizing microscopy and stained with endothelial cell markers (LEL, CD31), the progenitor cell marker CD34, and the macrophage marker ED-1. Microscopy demonstrated many diffuse vascular endothelial cells on the luminal surface of AVGs after placement. While there was no difference in the number of LEL-positive cells between the arterial side (AS) and venous side (VS) at 6h or 7days, there were significantly more of these cells on the VS at both 24h and 3days (p < 0.05). Analysis at 24h showed some CD31-positive cells and few CD34-positive cells. This was the first study to use a simple rat model of AVG placement. Endothelial cell formation was initially more active on the VS than on the AS, but these cells subsequently increased in number across the luminal surface. Future clinical studies might contribute clinically by confirming whether AS versus VS puncture results in different infection rates.

Central Line Access for Hemodialysis Adversely Affects Ipsilateral Arteriovenous Graft Outcomes

Central venous stenosis is a common problem that diminishes vascular access lifespan. Current national guidelines recommend that central catheters and arteriovenous grafts (AVGs) be placed contralateral to an existing hemodialysis access. We set forth to delineate any clinically significant outcomes based on laterality in patients undergoing AVG placement with an existing central catheter for dialysis treatments. Using a Veterans Administration Hospital dialysis access database over a four-year period (May 2014 to April 2018), we identified all patients who underwent AVG placement in an upper extremity with an existing ipsilateral (Ipsi-CL) or contralateral (Contra-CL) central line for hemodialysis. AVG outcomes examined included successful cannulation, functional patency, thrombosis events, and endovascular interventions per access site. Clinical records were also examined for location of AVG, arteriovenous fistula or AVG precursors, prior central line placement, peripherally inserted central catheter, and cardiac venous access. All outcomes were followed until July 2021. Student's t-test, Fisher's exact test, and multivariable analysis were used. A total of 71 AVGs: 55 (77%) were placed contralateral to existing central venous catheters and 16 (23%) were placed on the ipsilateral side. Baseline characteristics between the two groups were not found to be significantly different. This included a history of hypertension, smoking history, prior arteriovenous access, body mass index, race, glucose, creatinine, blood urea nitrogen, hemoglobin, mean corpuscular volume, platelet count, antiplatelet agent, and anticoagulation. 100% (n=16) of patients in the Ipsi-CL group had previous central venous access compared to 49.1% (n=27) in Contra-CL (P=<0.001). The mean functional patency for AVG with Contra-CL was 724.78±593.98days compared to AVGs with Ipsi-CL with mean days of 350.94±431.23days (P=0.001). A history of previous central venous catheterization and graft on ipsilateral side of a catheter at the time of surgery was associated with decreased functional duration of graft (odds ratio, 0.25; P=0.03). Within this cohort of patients that underwent AVG, we noted a statistically significant decrease in the duration of functional patency of grafts ipsilateral to central venous catheters. We did not find a difference in cannulation rates, thrombosis events, or overall endovascular interventions. Ipsilateral central access appears to be associated with decreased functional patency of AVGs. These findings highlight a discrepancy that is potentially clinically relevant and further studies are warranted.

FC098: Arteriovenous Access and Outcomes in Incident Hemodialysis Patients: Is Fistula First Approach Still Holding?

Abstract BACKGROUND AND AIMS Vascular access choice for patients with high risk of arteriovenous (AV) access failure has been sparking growing controversy as recent studies show similar survival and morbidity across patients receiving arteriovenous (AV) fistula or graft. We assessed hospitalization and mortality risks associated with access type in patients who started hemodialysis with a catheter without previous AV access creation in France, overall and by subgroups of age, sex and comorbidities. METHOD Longitudinal study of 18 800 incident hemodialysis patients from 2010 through 2018, based on the linkage of the French REIN registry of kidney replacement therapy (KRT) with the national health administrative database (SNDS). First-line AV access (fistula or graft) was ascertained from SNDS procedures codes. Hospitalizations were also identified through the SNDS, whereas mortality data was obtained from the REIN Registry. We used joint frailty models to estimate hazard ratios (HR) and 95% confidence intervals (CI) of recurrent hospitalization and death associated with AV grafts, compared with AV fistulæ. These models accounted for dependence between hospitalization and death. We further estimated propensity scores for first-line AV graft placement and used inverse probability weighting (IPW) to obtain weighted HR (wHR), accounting for potential indication bias. RESULTS Among studied patients, 35% were women, 45% had diabetes, 26% had history of heart failure and 19% had history of peripheral artery disease. More than half started dialysis urgently (52%). Patients with first-line AV graft (5%) were older than those with AV fistula (72 ± 14 versus 68 ± 15 years, respectively), and required more frequently assistance to walk (29% versus 17%). IPW resulted in covariate balance (absolute standardized difference &amp;lt;10%) within the overall population and the subgroups of interest (except for the timing of AV access creation in patients aged &amp;lt;70). Over a median follow-up of 48 months (IQR 27–48), hospitalization rates were 334 and 310 per 100 patient-years in the AV graft and fistula groups, respectively; mortality rates were 16 and 13 per 100 patient-years. Patients with AV graft had a 14% higher hazard of all-cause hospitalization (HR 1.14, 95% CI 1.08–1.20), which was only slightly attenuated in IPW analysis (wHR 1.11, 1.09–1.13). AV access type was not associated with mortality—HR 1.03 (0.89–1.19), wHR 1.11 (0.85–1.46). Results were consistent for most subgroups, except that the highest hazard of hospitalization with AV grafts compared to fistulæ was much attenuated in patients with diabetes, heart failure or peripheral artery disease with respect to patients without these comorbidities (Figure 1). CONCLUSION In patients starting hemodialysis with a catheter without previous AV access creation, the fistula first approach is associated with similar mortality, but lower risk of hospitalization compared to first-line AV graft. This may, however, not be the case for patients with a poor vascular condition, i.e. those with diabetes or peripheral artery disease, who have a similar hospitalization risk with either graft or fistula.

Technique for a lateral approach to a superficial femoral artery-femoral vein thigh loop arteriovenous graft placement in avoidance of a traditional groin incision.

The number of patients with end stage renal disease reliant on long-term hemodialysis access continues to grow. When traditional upper extremity hemodialysis sites are exhausted, lower extremity access should be considered. Although autogenous lower extremity options are available, prosthetic lower extremity grafts are frequently used. However, infection can complicate a significant percentage of lower extremity grafts with a traditional groin incision. We present our technique and early results of a lateral approach to a superficial femoral artery-femoral vein thigh loop arteriovenous graft (lat-SFA-FV AVG) in the proximal thigh, which avoids a traditional groin incision and provides a functional access with promising patency. Between April 2017 and August 2019, five lat-SFA-FV AVG were placed in our institution for arteriovenous access in patients who had exhausted options in upper extremities. Five patients were included in the study. Median SFA size was 8 mm. One patient had moderate SFA calcification, while the other four patients had either none or mild SFA calcification. All grafts were successfully placed with few postoperative complications, including no wound infections. One patient expired 3 weeks after the procedure due to unrelated cause. Three patients had functional grafts at a median follow-up of 499 days. Our early experience demonstrates that the lateral approach to the SFA-FV AVG has several advantages including avoidance of groin infection and acceptable patency. Furthermore, our early experience identifies patient factors which may be important to patient selection for this procedure.

Association of preoperative vein mapping with hemodialysis access characteristics and outcomes in the Vascular Quality Initiative

BackgroundPreoperative vein mapping before arteriovenous fistula (AVF) or arteriovenous graft (AVG) placement has been debated as a possible method of improving hemodialysis access outcomes for patients. However, high-quality national studies that have addressed this relationship are lacking. Thus, we assessed the association of preoperative vein mapping with hemodialysis access configuration and outcomes. MethodsIn the present cohort study, we analyzed all patients who had undergone AVF or AVG placement with data captured in the Vascular Quality Initiative hemodialysis access dataset from August 2011 to September 2019. The patients were stratified by whether they had undergone preoperative vein mapping. The primary (configuration) outcomes were access type (AVF vs AVG) and location (upper arm vs forearm). The secondary (longitudinal) outcomes were the successful initiation of hemodialysis, maintenance of secondary patency, and the need for reintervention 1 year after the index operation. ResultsOverall, 85.6% of the 46,010 included patients had undergone preoperative vein mapping. Of the 46,010 patients, 76.1% and 23.9% had undergone AVF and AVG creation, respectively. AVF creation (77.6% vs 67.3%) and forearm location (54.6% vs 47.3%) were more frequent for the patients who had undergone preoperative vein mapping than for those who had not (P < .001). After adjusting for baseline differences between the groups, preoperative vein mapping was associated with increased odds of receiving an AVF vs AVG (adjusted odds ratio, 1.64; 95% confidence interval [CI], 1.55-1.75) and forearm vs upper arm access (adjusted odds ratio, 1.22; 95% CI, 1.16-1.30). The incidence of the loss of secondary patency was lower for patients with preoperative vein mapping (P < .001), and persisted after risk adjustment (adjusted hazard ratio, 0.81; 95% CI, 0.75-0.88). ConclusionsPreoperative vein mapping was associated with favorable hemodialysis access configurations and outcomes in real-world practice. These data suggest that the use of preoperative vein mapping could improve the likelihood of favorable outcomes for patients requiring hemodialysis access.

Anticoagulation Therapy is Associated with Increased Access-related Wound Infections after Hemodialysis Access Creation

The effect of anticoagulation therapy (AC) on hemodialysis access patency and related complications is not well defined. Patients on long-term or chronic AC due to their underlying comorbid conditions may be particularly susceptible to access-related bleeding and complications from repetitive cannulation. Our goal is to assess the effect of anticoagulation therapy on outcomes after access creation. The Vascular Quality Initiative (VQI) database was queried for patients undergoing arteriovenous fistula (AVF) or graft (AVG) placement, from 2011 to 2019. Only patients with data on post-procedural AC status were included. Anticoagulation use was defined as patients on warfarin, dabigatran, or rivaroxaban after access creation at postoperative follow up. Demographic and procedural details were analyzed. Wound infection and patency rates at six months were assessed. Binomial logistic regression analysis was performed to assess the association of anticoagulation use with these outcomes. A total of 27,757 patients underwent access creation, with the majority undergoing AVF creation (78.8%). The average age was 61.4 years and 55.3% were male. 12.9% of patients were on postoperative AC. The wound infection rate was 2.3- 3.8% in the no AC and AC cohorts, respectively (P < 0.001). At six months follow-up, patency was 85.7- 84.3% in the no AC and AC cohorts, respectively (P=0.044). Expectedly, grafts had lower patency rates compared to AVF; those within the no AC cohort had a patency of 83.0% compared to 81.2 % in those on AC (P=0.106). On multivariable analysis, anticoagulation use was associated with a higher risk of wound infections (odds ratio [OR] 1.513, 95% confidence interval [CI] 1.160-1.973, P=0.002). AC use did not significantly affect access patency. Anticoagulation therapy was associated with a higher rate of wound infections but did not affect short-term access patency within six-months. These patients warrant close surveillance of their access for signs of infection. Furthermore, long-term implications of anticoagulation needs further evaluation.

The Effect of Race on Arteriovenous Graft Outcomes in a Veteran Dialysis Patient Population

Arteriovenous graft placement (AVG) is an established secondary hemodialysis access procedure. Previous studies have identified racial disparity as a confounding variable in hemodialysis access outcomes. We sought to examine our arteriovenous graft outcomes based on patient racial demographics in our veteran patient population.

Statins Usage at Arteriovenous Graft Placement Does Not Improve Outcomes in Diabetic Patients

The previous diabetic arteriovenous fistula animal model indicates improved flow dynamics with the use of HMG-CoA-reductase inhibitors (statins). We have reported on few thrombosis events in patients on statins who had successful cannulation of their radiocephalic arteriovenous fistula. We predict similar favorable outcomes in diabetic patients undergoing arteriovenous graft (AVG) placements.

Central Line Access for Hemodialysis Adversely Affects Ipsilateral Arteriovenous Graft Outcomes

Current national guidelines recommend that if a central catheter is needed for dialysis treatment, contralateral placement placements should be favored over an ipsilateral position. Previous venogram studies have demonstrated a central venous stenosis incidence of about 50% in patients with central access. We set forth to delineate any clinically significant outcomes in patients with an ipsilateral or contra lateral central catheter for dialysis treatments at the time of arteriovenous graft (AVG) placement.

Arteriovenous Vascular Access–Related Procedural Burden Among Incident Hemodialysis Patients in the United States

As the proportion of arteriovenous fistulas (AVFs) compared with arteriovenous grafts (AVGs) in the United States has increased, there has been a concurrent increase in interventions. We explored AVF and AVG maturation and maintenance procedural burden in the first year of hemodialysis. Observational cohort study. Patients initiating hemodialysis from July 1, 2012, to December 31, 2014, and having a first-time AVF or AVG placement between dialysis initiation and 1 year (N= 73,027), identified using the US Renal Data System (USRDS). Patient characteristics. Successful AVF/AVG use and intervention procedure burden. For each group, we analyzed interventional procedure rates during maturation maintenance phases using Poisson regression. We used proportional rate modeling for covariate-adjusted analysis of interventional procedure rates during the maintenance phase. During the maturation phase, 13,989 of 57,275 patients (24.4%) in the AVF group required intervention, with therapeutic interventional requirements of 0.36 per person. In the AVG group 2,904 of 15,572 patients (18.4%) required intervention during maturation, with therapeutic interventional requirements of 0.28 per person. During the maintenance phase, in the AVF group 12,732 of 32,115 patients (39.6%) required intervention, with a therapeutic intervention rate of 0.93 per person-year. During maintenance phase, in the AVG group 5,928 of 10,271 patients (57.7%) required intervention, with a therapeutic intervention rate of 1.87 per person-year. For both phases, the intervention rates for AVF tended to be higher on the East Coast while those for AVG were more uniform geographically. This study relies on administrative data, with monthly recording of access use. During maturation, interventions for both AVFs and AVGs were relatively common. Once successfully matured, AVFs had lower maintenance interventional requirements. During the maturation and maintenance phases, there were geographic variations in AVF intervention rates that warrant additional study.

Catheter Dependence After Arteriovenous Fistula or Graft Placement Among Elderly Patients on Hemodialysis

Creation of an arteriovenous fistula (AVF), compared with an arteriovenous graft (AVG), is associated with longer initial catheter dependence after starting hemodialysis (HD) but longer access survival and lower long-term catheter dependence. The extent of these potential long-term benefits in elderly patients is unknown. We assessed catheter dependence after AVF or AVG placement among elderly patients who initiated HD without a permanent access in place. Retrospective cohort study. Patients≥67 years of age identified in the US Renal Data System who had a first AVF (n=14,532) or AVG (n=3,391) placed within 1 year after HD initiation between May 2012 and May2017. AVF versus AVG placement in the first year of HD. Catheter dependence after AVF or AVG placement assessed using CROWNWeb data. Generalized estimating equations and negative binomial regression for catheter use over time and Cox proportional hazards models for mortality. Creation of an AVF versus AVG placement was associated with greater catheter dependence at 1 month (95.6% vs 92.5%) and 3 months (82.8% vs 41.2%), but lower catheter dependence at 12 months (14.2% vs 15.8%) and 36 months (8.2% vs 15.0%). Creation of an AVF, however, remained significantly associated with greater cumulative catheter-dependent days (80.1 vs 54.6 days per person-year) and a lower proportion of catheter-free survival time (78.1% vs 85.1%) after 3 years of follow-up. Potential for unmeasured confounding and analyses limited to elderly patients. Creation of an AVF was associated with significantly greater cumulative catheterdependence than placement of an AVGin an elderly population initiating HD without a permanent access. As the long-term benefits in terms of catheter dependence of an AVF are not realized in many elderly patients, specific patient characteristics should be considered when making decisions regarding vascular access.

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

BackgroundIt is unclear whether surgical placement of an arteriovenous (AV) fistula (AVF) confers substantial clinical benefits over an AV graft (AVG) in older adults with end-stage kidney disease (ESKD). We report vascular access outcomes of a pilot clinical trial.Study DesignPilot randomized parallel-group open-label trial.Setting & ParticipantsPatients 65 years and older with ESKD and no prior AV access receiving maintenance hemodialysis through a tunneled central venous catheter referred for AV access placement by their treating nephrologist.InterventionParticipants were randomly assigned in a 1:1 ratio to surgical placement of an AVG or AVF.OutcomesIndex AV access primary failure, successful cannulation, adjuvant interventions and infections.ResultsOf 122 older adults receiving hemodialysis and no prior AV access surgery, 24% died before (n = 18) or were too sick for (n = 11) referral for a permanent AV access. Of 46 eligible patients, 36 (78%) consented and were randomly assigned to AVG (n = 18) and AVF (n = 18) placement, of whom 13 (72%) and 16 (89%) underwent index AV access surgical placement, respectively. At a median follow-up of 321.0 days, primary AV access failure was noted in 31% in each group. The proportion of patients with successful cannulation was 62% (8 of 13) in the AVG and 50% (8 of 16) in the AVF group; median times to successful cannulation were 75.0 and 113.5 days, respectively. Endovascular procedures were recorded in 38% and 44%, and surgical reinterventions, in 23% and 25%, respectively. AV access infection was seen in 3 (23%) and 2 (13%) patients, respectively.LimitationsSmall sample size precludes statistical inference.ConclusionsAlmost one-quarter of older adults with incident ESKD and a central venous catheter as primary access were not referred for AV access placement due to medical reasons. Based on these limited results, there is little reason to favor either an AVF or AVG in this population until results from a larger randomized clinical trial become available.FundingGovernment funding to an author (Dr Murea is supported by National Institutes of Health∖National Institute on Aging grant 1R03 AG060178-01).Trial RegistrationNCT03545113.

Policy and Pandemic: The Changing Practice of Nephrology During the Coronavirus Disease-2019 Outbreak.

The coronavirus (coronavirus disease-2019) pandemic has changed care delivery for patients with end-stage kidney disease. We explore the US healthcare system as it pertains to dialysis care, including existing policies, modifications implemented in response to the coronavirus disease-2019 crisis, and possible next steps for policy makers and nephrologists. This includes policies related to resource management, use of telemedicine, prioritization of dialysis access procedures, expansion of home dialysis modalities, administrative duties, and quality assessment. The government has already established policies that have instated some flexibilities to help providers focus their response to the crisis. However, future policy during and after the coronavirus disease-2019 pandemic can bolster our ability to optimize care for patients with end-stage kidney disease. Key themes in this perspective are the importance of policy flexibility, clear strategies for emergency preparedness, and robust health systems that maximize accessibility and patient autonomy.

The Effect of Race on Arteriovenous Graft Outcomes in a Veteran Dialysis Patient Population

Arteriovenous graft (AVG) placement is an established secondary hemodialysis access procedure. Previous studies have identified racial disparity as a confounding variable in hemodialysis access outcomes. We sought to examine our AVG outcomes based on patients' racial demographics in our veteran patient population.

Central Line Access for Hemodialysis Adversely Affects Ipsilateral Arteriovenous Graft

Current national guidelines recommend that if a central catheter is needed for dialysis treatment, contralateral placement should be favored over an ipsilateral position. Previous venography studies have demonstrated a central venous stenosis incidence of about 50% in patients with central access. We set forth to delineate any clinically significant outcomes in patients undergoing arteriovenous graft (AVG) placement relative to an existing ipsilateral or contralateral central catheter for dialysis treatments.