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Background and Objectives: Referring hemodialysis patients for elective access angiography and percutaneous transluminal angioplasty (PTA) is commonly done to prevent access failure, yet the effectiveness of this procedure remains unclear. DESIGN, SETTING, PARTICIPANTS, & MEASURES: An observational matched cohort analysis among 40,132 Medicare beneficiaries receiving hemodialysis with a fistula or graft was performed. Cox regression was used to determine whether access intervention was associated with improved 1-year access survival., Results: Nonsurgical access intervention was found to be frequent at a rate of 20.9 procedures per 100 access years. In the 1-year period after intervention using angiography and PTA, the overall access failure rate was 53.7 per 100 access years in the intervention group and 49.6 in the nonintervention group (HR = 1.02; 95% CI, 0.96 to 1.08). Similar findings were also seen when the analysis was repeated in only fistulas (HR = 1.06; 95% CI, 0.98 to 1.15) and grafts (HR = 0.95; 95% CI, 0.86 to 1.05). In patients with a low intra-access flow rate (HR = 0.86; 95% CI, 0.75 to 0.99) or a new access (HR = 0.79; 95% CI, 0.71 to 0.89), angiography and PTA significantly increased access survival when compared with nonintervention (P for interaction was <0.0001). Angiography-PTA-related upper-extremity hematoma, vessel injury, or embolism-thrombosis occurred in 1.1% of all patients., Conclusions: Access characteristics significantly modify the survival benefits of angiography and PTA intervention where the benefits of these interventions are most seen in newer accesses or accesses with insufficient flow.

Background and Objectives: Conversion from central venous catheters to a graft or a fistula is associated with lower mortality risk in long-term hemodialysis (HD) patients; however, a similar association with hospitalization risk remains to be elucidated., Design, Setting, Participants, & Measurements: We conducted a prospective observational study all maintenance in-center HD patients who were treated in Fresenius Medical Care, North America legacy facilities; were alive on January 1, 2007; and had baseline laboratory data from December 2006. Access conversion (particularly from a catheter to a fistula or a graft) during the 4-month period from January 1 through April 30, 2007, was linked using Cox models to hospitalization risk during the succeeding 1-year follow-up period (until April 30, 2008)., Results: The cohort (N = 79,545) on January 1, 2007 had 43% fistulas, 29% catheters, and 27% grafts. By April 30, 2007, 70,852 patients were still on HD, and among 19,792 catheters initially, only 10.3% (2045 patients) converted to either a graft or a fistula. With catheters as reference, patients who converted to grafts/fistulas had similar adjusted hazard ratios (0.69) as patients on fistulas (0.71), while patients with fistulas/grafts who converted to catheters did worse (1.22), all P < 0.0001., Conclusions: Catheters remain associated with the greatest hospitalization risk. Conversion from a catheter to either graft or fistula had significantly lower hospitalization risk relative to keeping the catheter. Prospective studies are needed to determine whether programs that reduce catheters will decrease hospitalization risk in HD patients.

Eighty-two percent (82%) of patients initiating hemodialysis in the United States in 2006 did so with a catheter as the functioning access. Even in patients who have been followed by nephrologists for 6 months or more, 74% of patients initiated dialysis with a catheter. This is a multifactoral problem that requires attention and solutions from all stakeholders, including the nephrologist, the vascular surgeon, the hospital, and the insurance industry, as well as the patient and family. We propose a series of specific proposals that include a process for the timely referral and timely placement of a permanent access based on the patient's estimated or measured glomerular filtration rate (GFR), and a 'pay-for-performance' measure for vascular surgeons and nephrologists who admit patients with functional permanent accesses; such pay for performance would place a higher value for patients who are admitted with a functional arteriovenous (AV) fistula than for patients who are admitted with an AV graft. We also propose that hospitals develop a less permissive process for placement of PICC (peripherally inserted central catheters) lines in patients with GFR <60 ml/min and to consider surgery for access placement as 'urgent'. Finally, a more proactive educational process for patients and their families, including an 'informed non-consent' for patients who defer placement of a permanent access needs to be considered. The morbidity, mortality, and health-care costs associated with prolonged catheter use mandate urgent attention to this problem.

Background: We hypothesized that a change from central venous catheters to a fistula or graft would improve short-term mortality risk in maintenance hemodialysis patients., Design: Prospective observational study., Setting & Participants: All maintenance in-center hemodialysis patients treated in Fresenius Medical Care, North America legacy facilities alive on January 1, 2007 with baseline laboratory data from December 2006., Predictor: Access type (fistula, catheter, or graft), determined on December 31, 2006, and monthly thereafter. Conversion from a catheter to a fistula or graft during the 4-month period from January 1 to April 30, 2007., Outcome: Mortality was tracked from May 1, 2007, to December 31, 2007. Standard and time-dependent Cox models were used to determine hazard risks (HRs) of death with and without adjustment for case-mix and laboratory values., Results: At baseline, 79,545 patients had 43% fistulas, 29% catheters, and 27% grafts. Mean age was 62 +/- 15 years, 54% were men, 51% were white, and 53% had diabetes. Compared with fistulas, unadjusted HRs of death were higher for grafts (1.22) and catheters (1.76; P < 0.001). In adjusted models, overall risk for grafts was decreased to 1.05 (95% limits, 1.003-1.100; P < 0.05) and approached that for fistulas consistently across multiple strata. Compared with patients who continued using a catheter, those who converted to either a graft or fistula had an HR of 0.69, whereas those who converted from a graft or fistula to a catheter had increased HRs to 2.12 (both P < 0.001). Similar trends were observed in the subset of incident patients (vintage < 90 days at study onset)., Limitations: Observational design with residual confounding from unmeasured patient, facility, and treatment-related factors., Conclusions: Catheters have the worst associated mortality risk. Changing from a catheter to a fistula or graft is associated with significantly improved survival. The risk for grafts approached that of fistulas, providing an alternative to prolonged catheter exposure and potentially less hazardous "bridge" toward a fistula.

Background and Objectives: Patient knowledge about chronic hemodialysis (CHD) is important for effective self-management behaviors, but little is known about its association with vascular access use., Design, Setting, Participants, & Measurements: Prospective cohort of adult incident CHD patients from May 2002 until November 2005 and followed for 6 mo after initiation of hemodialysis (HD). Patient knowledge was measured using the Chronic Hemodialysis Knowledge Survey (CHeKS). The primary outcome was dialysis access type at: baseline, 3 mo, and 6 mo after HD initiation. Secondary outcomes included anemia, nutritional, and mineral laboratory measures., Results: In 490 patients, the median (interquartile range) CHeKS score (0 to 100%) was 65%[52% to 78%]. Lower scores were associated with older age, fewer years of education, and nonwhite race. Patients with CHeKS scores 20 percentage points higher were more likely to use an arteriovenous fistula or graft compared with a catheter at HD initiation and 6 mo after adjustment for age, sex, race, education, and diabetes mellitus. No statistically significant associations were found between knowledge and laboratory outcome measures, except for a moderate association with serum albumin. Potential limitations include residual confounding and an underpowered study to determine associations with some clinical measures., Conclusions: Patients with less dialysis knowledge may be less likely to use an arteriovenous access for dialysis at initiation and after starting hemodialysis. Additional studies are needed to explore the impact of patient dialysis knowledge, and its improvement after educational interventions, on vascular access in hemodialysis.

The success of Fistula First nationwide has been accompanied by an unplanned increase in hemodialysis catheters. Complications related to prolonged hemodialysis catheter use include increased morbidity, mortality, and cost. We hypothesize that the national focus on increasing fistulas may have inadvertently diverted attention away from initiatives to decrease dependence on hemodialysis catheters. Based on a synthesis of guidelines, reviews, published evidence, and the authors' opinions, we propose that the national vascular access initiative be revised to have a dual goal of Fistula First and "Catheters Last." These goals are not mutually exclusive, but rather complementary. We recommend a systematic refocus on interventions that not only increase fistulas, but help avoid extended catheter use. Clearly, the ideal practice for hemodialysis vascular access remains early placement of fistulas with enough maturation time such that they can be used for initiating long-term hemodialysis therapy when the need arises. To effect this change, a reimbursement policy covering the costs associated with permanent access placement before the need for dialysis is essential. Individualized patient management strategies may consider such innovative approaches as initiating patients on peritoneal dialysis therapy or using nonautogenous grafts as bridge accesses in lieu of catheters. For patients who are dialyzing using catheters, immediate active planning for permanent access placement and removal of the catheter is necessary. In the same vein as Fistula First, the renal community should once again be galvanized in working together toward controlling the catheter epidemic in our dialysis population.

Background: Vascular access thrombosis accounts for at least $1 billion dollars in annual expenses and 25% of hospitalizations for chronic hemodialysis patients. Low vascular access blood flow (less than 800 ml/min) has been shown to modestly increase the relative risk for thrombosis in the subsequent three months. In this study, it is hypothesized that a time-dependent decrease in vascular access blood flow may be more predictive of subsequent thrombosis especially in vascular accesses with flows more than 800 ml/min, since it would indicate the development of a critical outlet stenosis in the graft., Methods: Ninety-five accesses in 91 CHD patients were prospectively followed over 18 months. Vascular access blood flow was measured every six months by the ultrasound dilution technique. Thrombotic events were recorded during the three study periods., Results: A total of 34 thrombotic events in 95 accesses were documented through the total study duration. Accesses that thrombosed had a 22% decrease in vascular access blood flow during the first observation period and a further 41% decrease during the second observation period as compared to 4% drop and 15% increase during the first and second observation periods, respectively, for accesses that did not thrombose. There was an estimated 13.6-fold (95%, confidence interval 2.68 to 69.16) increase in the relative risk of thrombosis for accesses with more than 35% decrease in vascular access blood flow compared to those accesses with no change in blood flow. There was no statistical difference in the average vascular access blood flow of all patients over the study period., Conclusions: Accesses that show a large (>15%) decrement in vascular access blood flow are associated with a high risk of thrombosis. Serial measurements of vascular access blood flow predict access thrombosis.

Malfunction of permanent vascular accesses remains a cause of frequent and costly morbidity in patients receiving chronic hemodialysis (CHD). Several recommendations for routine monitoring of these permanent vascular accesses for incipient failure have been proposed. In this study, multiple indicators of incipient vascular access dysfunction, including "venous" and "arterial" pressures at serial blood flows (200 ml/min, 300 ml/min, and 400 ml/min), percent urea recirculation, Doppler ultrasound, and access blood flow by ultrasound dilution technique were simultaneously evaluated in a total of 220 vascular accesses in 170 chronic hemodialysis patients in two separate study periods (6 months apart). The rate of thrombosis was determined within the subsequent 12 weeks of each study period to assess the short-term predictive power of access thrombosis. During the period of follow-up, there were 34 thrombotic events in 172 polytetrafluoroethylene (PTFE) grafts and only one thrombotic event in 48 arterio-venous fistulas (AVF). Therefore, the statistical analysis was limited to the PTFE grafts. When grafts with thromboses were compared to those without thrombosis by univariate analysis, access blood flow measured either by ultrasound dilution technique (875 +/- 426 ml/min with thrombosis vs. 1193 +/- 677 ml/min without thrombosis, P = 0.001) or by Doppler ultrasound (762 +/- 420 ml/min with thrombosis vs. 1171 +/- 657 ml/min without thrombosis, P = 0.001) were significantly different in the two groups. There was good correlation (r = 0.79, P = 0.0001) between the blood flows determined by both techniques. The grade of stenosis determined by ultrasound was also a statistically significant predictor (P = 0.02). "Venous" and "arterial" pressures were numerically similar and were not statistically different between the accesses that did and those that did not thrombose. When multivariate analysis was used, there was a significantly increased risk of thrombosis only with decreasing access blood flow determined by ultrasound dilution techniques after adjusting for other confounding variables. When the average blood flow of all grafts (1134 ml/min) is considered as the reference access blood flow (relative risk of 1.0), the relative risk of a PTFE thrombotic event within the subsequent 12 weeks was 1.23 at a blood flow 950 ml/min, 1.67 at a blood flow of 650 ml/min and to 2.39 at a blood flow of 300 ml/min. In summary, access blood flow measured by either Dilution or Doppler is a reliable indicator of subsequent short-term thrombosis risk. Other proposed methods of evaluating access dysfunction were not useful in our patients. If simple to use, cost-effective devices to measure dialysis access blood flow become readily available, the measurement of access blood flow will likely become the method of choice for screening of PTFE vascular access dysfunction in hemodialysis patients.

Over a 4-year interval, 324 arteriovenous conduits were created in 256 patients with end-stage renal disease as access for chronic hemodialysis. These included 154 Cimino fistulae, 163 polytetrafluoroethylene (PTFE) grafts, and seven miscellaneous grafts. Satisfactory patency rates were demonstrated for as long as 4 years for both Cimino fistulae and PTFE grafts by life-table analysis. Failures of Cimino fistulae usually occurred early in the postoperative period, secondary to attempts to use inadequate veins. Thrombosis caused the majority of PTFE graft failures and was generally the result of venous stenosis. Correction of such venous stenosis is mandatory to restore graft patency and can result in prolonged graft survival.