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Charmaine E Lok - One of the best experts on this subject based on the ideXlab platform.
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kdoqi clinical practice guideline for Vascular Access 2019 update
American Journal of Kidney Diseases, 2020Co-Authors: Charmaine E Lok, Timmy Lee, Michael Allon, Thomas S Huber, Surendra Shenoy, Alexander S Yevzlin, Kenneth Abreo, Arif Asif, Brad C Astor, Marc H GlickmanAbstract:The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis Vascular Access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their Vascular Access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on Vascular Access choice, new targets for arteriovenous Access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.
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new insights into dialysis Vascular Access what is the optimal Vascular Access type and timing of Access creation in ckd and dialysis patients
Clinical Journal of The American Society of Nephrology, 2016Co-Authors: Karen Woo, Charmaine E LokAbstract:Optimal Vascular Access planning begins when the patient is in the predialysis stages of CKD. The choice of optimal Vascular Access for an individual patient and determining timing of Access creation are dependent on a multitude of factors that can vary widely with each patient, including demographics, comorbidities, anatomy, and personal preferences. It is important to consider every patient's ESRD life plan (hence, their overall dialysis Access life plan for every Vascular Access creation or placement). Optimal Access type and timing of Access creation are also influenced by factors external to the patient, such as surgeon experience and processes of care. In this review, we will discuss the key determinants in optimal Access type and timing of Access creation for upper extremity arteriovenous fistulas and grafts.
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preoperative Vascular Access evaluation for haemodialysis patients
Cochrane Database of Systematic Reviews, 2015Co-Authors: Sarah Daisy Kosa, Louise Moist, Charmaine E Lok, Ahmed A AljaishiAbstract:Background Haemodialysis treatment requires reliable Vascular Access. Optimal Access is provided via functional arteriovenous fistula (fistula), which compared with other forms of Vascular Access, provides superior long-term patency, requires few interventions, has low thrombosis and infection rates and cost. However, it has been estimated that between 20% and 60% of fistulas never mature sufficiently to enable haemodialysis treatment. Mapping blood vessels using imaging technologies before surgery may identify vessels that are most suitable for fistula creation. Objectives We compared the effect of conducting routine radiological imaging evaluation for Vascular Access creation preoperatively with standard care without routine preoperative vessel imaging on fistula creation and use. Search methods We searched Cochrane Kidney and Transplant's Specialised Register to 14 April 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review. Selection criteria We included randomised controlled trials (RCTs) that enrolled adult participants (aged ≥ 18 years) with chronic or end-stage kidney disease (ESKD) who needed fistulas (both before dialysis and after dialysis initiation) that compared fistula maturation rates relating to use of imaging technologies to map blood vessels before fistula surgery with standard care (no imaging). Data collection and analysis Two authors assessed study quality and extracted data. Dichotomous outcomes, including fistula creation, maturation and need for catheters at dialysis initiation, were expressed as risk ratios (RR) with 95% confidence intervals (CI). Continuous outcomes, such as numbers of interventions required to maintain patency, were expressed as mean differences (MD). We used the random-effects model to measure mean effects. Main results Four studies enrolling 450 participants met our inclusion criteria. Overall risk of bias was judged to be low in one study, unclear in two, and high in one.There was no significant differences in the number of fistulas that were successfully created (4 studies, 433 patients: RR 1.06, 95% CI 0.95 to 1.28; I² = 76%); the number of fistulas that matured at six months (3 studies, 356 participants: RR 1.11, 95% CI 0.98 to 1.25; I² = 0%); number of fistulas that were used successfully for dialysis (2 studies, 286 participants: RR 1.12, 95% CI 0.99 to 1.28; I² = 0%); the number of patients initiating dialysis with a catheter (1 study, 214 patients: RR 0.66, 95% CI 0.42 to 1.04); and in the rate of interventions required to maintain patency (1 study, 70 patients: MD 14.70 interventions/1000 patient-days, 95% CI -7.51 to 36.91) between the use of preoperative imaging technologies compared with standard care (no imaging). Authors' conclusions Based on four small studies, preoperative vessel imaging did not improve fistula outcomes compared with standard care. Adequately powered prospective studies are required to fully answer this question.
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Vascular Access morbidity and mortality trends of the last decade
Clinical Journal of The American Society of Nephrology, 2013Co-Authors: Charmaine E Lok, Robert N FoleyAbstract:Summary During the past decade, clear trends in the types of incident and prevalent hemodialysis Vascular Access can be observed. There has been a steady increase and recent stabilizaton of patients initiating hemodialysis with a central venous catheter, representing approximately 80% of all incident Accesses. There has also been a steady increase in prevalent fistula use, currently greater than 50% within 4 months of hemodialysis initiation. Patient and Vascular Access related morbidity and mortality are reflected in the type of Vascular Access used at initiation and for long-term maintenance dialysis. There is a three- to fourfold increase in risk of infectious complications in patients initiating dialysis with a catheter compared with either a fistula or graft and a sevenfold higher risk when the catheter is used as a prevalent Access. Procedure rates have increased two- to threefold for all types of Access. There is a significant increased risk of mortality associated with catheter use, especially within the first year of dialysis initiation.
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standardized definitions for hemodialysis Vascular Access
Seminars in Dialysis, 2011Co-Authors: Timmy Lee, Michele H Mokrzycki, Louise Moist, Ivan D Maya, Miguel A Vazquez, Charmaine E LokAbstract:Vascular Access dysfunction is one of the leading causes of morbidity and mortality among end-stage renal disease patients. Vascular Access dysfunction exists in all three types of available Accesses: arteriovenous fistulas, arteriovenous grafts, and tunneled catheters. To improve clinical research and outcomes in hemodialysis (HD) Access dysfunction, the development of a multidisciplinary network of collaborative investigators with various areas of expertise, and common standards for terminology and classification in all Vascular Access types, is required. The North American Vascular Access Consortium (NAVAC) is a newly formed multidisciplinary and multicenter network of experts in the area of HD Vascular Access, who include nephrologists and interventional nephrologists from the United States and Canada with: (1) a primary clinical and research focus in HD Vascular Access dysfunction, (2) national and internationally recognized experts in Vascular Access, and (3) a history of productivity measured by peer-reviewed publications and funding among members of this consortium. The consortium's mission is to improve the quality and efficiency in Vascular Access research, and impact the research in the area of HD Vascular Access by conducting observational studies and randomized controlled trials. The purpose of the consortium's initial manuscript is to provide working and standard Vascular Access definitions relating to (1) epidemiology, (2) Vascular Access function, (3) Vascular Access patency, and (4) complications in Vascular Accesses relating to each of the Vascular Access types.
Philip J Held - One of the best experts on this subject based on the ideXlab platform.
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Vascular Access use in europe and the united states results from the dopps
Kidney International, 2002Co-Authors: Ronald L Pisoni, Eric W Young, Dawn M Dykstra, Roger Greenwood, Erwin Hecking, Brenda W Gillespie, Robert A Wolfe, David A Goodkin, Philip J HeldAbstract:Vascular Access use in Europe and the United States: Results from the DOPPS. Background A direct broad-based comparison of Vascular Access use and survival in Europe (EUR) and the United States (US) has not been performed previously. Case series reports suggest that Vascular Access practices differ substantially in the US and EUR. We report on a representative study (DOPPS) which has used the same data collection protocol for> 6400 hemodialysis (HD) patients to compare Vascular Access use at 145 US dialysis units and 101 units in five EUR countries (France, Germany, Italy, Spain, and the United Kingdom). Methods Logistic analysis evaluated factors associated with native arteriovenous fistula (AVF) versus graft use or permanent Access versus catheter use for prevalent and incident HD patients. Times to failure for AVF and graft were analyzed using Cox proportional hazards regression. Results AVF was used by 80% of EUR and 24% of US prevalent patients, and was significantly associated with younger age, male gender, lower body mass index, non-diabetic status, lack of peripheral Vascular disease, and no angina. After adjusting for these factors, AVF versus graft use was still much higher in EUR than US (AOR = 21, P P 30 days prior to ESRD compared with 74% in the US ( P P = 0.01). New HD patients had a 1.8-fold greater odds ( P = 0.002) of starting HD with a permanent Access if a facility's typical time from referral to Access placement was ≤2 weeks. AVF use when compared to grafts was substantially lower (AOR = 0.61, P = 0.04) when surgery trainees assisted or performed Access placements. When used as a patient's first Access, AVF survival was superior to grafts regarding time to first failure (RR = 0.53, P = 0.0002), and AVF survival was longer in EUR compared with the US (RR = 0.49, P = 0.0005). AVF and grafts each displayed better survival if used when initiating HD compared with being used after patients began dialysis with a catheter. Conclusion Large differences in Vascular Access use exist between EUR and the US, even after adjustment for patient characteristics. The results strongly suggest that a facility's preferences and approaches to Vascular Access practice are major determinants of Vascular Access use.
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Vascular Access survival among incident hemodialysis patients in the united states
American Journal of Kidney Diseases, 1997Co-Authors: John D Woods, Eric W Young, Richard A Hirth, Marc N Turenne, Friedrich K Port, Robert L Strawderman, Philip J HeldAbstract:Vascular Access failure causes substantial morbidity to hemodialysis patients. We sought to identify factors determining survival of the permanent Vascular Access in use at the start of end-stage renal disease during 1990 in a national sample of 784 incident hemodialysis patients insured by Medicare. Medicare claims records were used to identify Access failures or revisions among patients with an arteriovenous (AV) fistula (n = 245) and an AV Vascular graft (n = 539). A proportional hazards analysis of time to first failure or revision, controlled by stratification for sex, race, and cause of end-stage renal disease, was used to determine the effect of age, Access type, and peripheral Vascular disease on Vascular Access survival. Patients with an AV fistula and who were older than 65 years had a risk of Access failure that was 24% lower than similar patients with an AV graft (P < 0.02). The relative risk of Access failure for an AV fistula, but not an AV graft, varied significantly with age for patients younger than 65 years (P < 0.01). The relative risk of Access failure for a patient with an AV fistula, compared with a patient of the same age with an AV graft, was 67% lower at the age of 40 years, 54% lower at the age of 50 years, and 24% lower at the age of 65 years. A history of peripheral Vascular disease was associated with a 24% higher risk of AV graft or fistula failure (P = 0.05). Measures to decrease Vascular Access-related morbidity among hemodialysis patients should include reversing the current trend toward increasing use of AV grafts, particularly in patients younger than 65 years.
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predictors of type of Vascular Access in hemodialysis patients
JAMA, 1996Co-Authors: Richard A Hirth, Eric W Young, Marc N Turenne, John D Woods, Friedrich K Port, Mark V Pauly, Philip J HeldAbstract:Objective. —Complications from Vascular Access account for 15% of hospital admissions among US hemodialysis patients. Complications are less frequent with arteriovenous fistulas than with synthetic grafts. We assessed clinical and nonclinical predictors of whether patients with end-stage renal disease (ESRD) starting hemodialysis receive a fistula or graft. We also investigated changes in practice between 1986-1987 and 1990. Design. —Cross-sectional study. Setting. —United States hemodialysis population. Patients. —Random, national samples of ESRD patients who started hemodialysis in 1986-1987 (n=2741) or 1990 (n=1409) from United States Renal Data System Special Studies. Main Outcome Measure. —Type of permanent Vascular Access (arteriovenous fistula vs synthetic graft), analyzed using multivariate logistic regression. Results. —Clinical and demographic factors as well as socioeconomic status, region of residence, and year starting hemodialysis predicted the type of Vascular Access. Overall, 56% of patients had grafts 30 days after starting dialysis, but graft use increased from 51% in 1986-1987 to 65% in 1990 (adjusted odds ratio [AOR], 1.67for 1990 vs 1986-1987; 95% confidence interval [CI], 1.43-1.95; P P P Concclusions. —This national study documents large variations in the relative use of fistulas and grafts and a trend away from fistulas. The prevalence of comorbid conditions fails to explain these findings. Presentation and referral of patients early in the process of their ESRD, teaching surgeons to place fistulas, and training dialysis nurses to Access fistulas may increase their use.
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hemodialysis Vascular Access morbidity in the united states
Kidney International, 1993Co-Authors: Harold I Feldman, Philip J Held, John T Hutchinson, Eva Stoiber, Marguerite F HartiganAbstract:Hemodialysis Vascular Access morbidity in the United States. Extensive morbidity related to hemodialysis Vascular Access exists among endstage renal disease (ESRD) patients, but the risk factors for this morbidity have not been extensively studied. Medicare ESRD patient data were obtained from 1984, 1985, and 1986. Hospitalization for Vascular Access morbidity (ICD-996.1, 996.6, or 996.7) was analyzed among prevalent patients and, using survival analysis, among incident patients to assess sex, age, race, and underlying cause of renal failure as risk factors. We found that 15 to 16% of hospital stays among prevalent ESRD patients were associated with Vascular Access-related morbidity. Black race, older age, female sex, and diabetes mellitus as a cause of kidney failure were all independent risk factors for Access-related morbidity. The rate ratio comparing Blacks to Whites was 1.12 (95% C.I., 1.09, 1.16); > 64 years to 20 to 44 years, 1.53 (1.46, 1.59); men to women, 0.81 (0.79, 0.84); and diabetes to glomerulonephritis, 1.29 (1.24, 1.35). We conclude that hemodialysis Vascular Access malfunction causes much hospitalization among ESRD patients. Women, Blacks, the elderly, and diabetics appear to be at particularly high risk, and additional studies are needed to understand these patterns.
Andrea Remuzzi - One of the best experts on this subject based on the ideXlab platform.
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blood flow in idealized Vascular Access for hemodialysis a review of computational studies
Cardiovascular Engineering and Technology, 2017Co-Authors: Bogdan Eneiordache, Andrea RemuzziAbstract:Although our understanding of the failure mechanism of Vascular Access for hemodialysis has increased substantially, this knowledge has not translated into successful therapies. Despite advances in technology, it is recognized that Vascular Access is difficult to maintain, due to complications such as intimal hyperplasia. Computational studies have been used to estimate hemodynamic changes induced by Vascular Access creation. Due to the heterogeneity of patient-specific geometries, and difficulties with obtaining reliable models of Access vessels, idealized models were often employed. In this review we analyze the knowledge gained with the use of computational such simplified models. A review of the literature was conducted, considering studies employing a computational fluid dynamics approach to gain insights into the flow field phenotype that develops in idealized models of Vascular Access. Several important discoveries have originated from idealized model studies, including the detrimental role of disturbed flow and turbulent flow, and the beneficial role of spiral flow in intimal hyperplasia. The general flow phenotype was consistent among studies, but findings were not treated homogeneously since they paralleled achievements in cardioVascular biomechanics which spanned over the last two decades. Computational studies in idealized models are important for studying local blood flow features and evaluating new concepts that may improve the patency of Vascular Access for hemodialysis. For future studies we strongly recommend numerical modelling targeted at accurately characterizing turbulent flows and multidirectional wall shear disturbances.
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the molecular mechanisms of hemodialysis Vascular Access failure
Kidney International, 2016Co-Authors: Akshaar Brahmbhatt, Andrea Remuzzi, Marco Franzoni, Sanjay MisraAbstract:The arteriovenous fistula has been used for more than 50 years to provide Vascular Access for patients undergoing hemodialysis. More than 1.5 million patients worldwide have end stage renal disease and this population will continue to grow. The arteriovenous fistula is the preferred Vascular Access for patients, but its patency rate at 1 year is only 60%. The majority of arteriovenous fistulas fail because of intimal hyperplasia. In recent years, there have been many studies investigating the molecular mechanisms responsible for intimal hyperplasia and subsequent thrombosis. These studies have identified common pathways including inflammation, uremia, hypoxia, sheer stress, and increased thrombogenicity. These cellular mechanisms lead to increased proliferation, migration, and eventually stenosis. These pathways work synergistically through shared molecular messengers. In this review, we will examine the literature concerning the molecular basis of hemodialysis Vascular Access malfunction.
Harold I Feldman - One of the best experts on this subject based on the ideXlab platform.
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hemodialysis Vascular Access morbidity
Journal of The American Society of Nephrology, 1996Co-Authors: Harold I Feldman, Sidney Kobrin, Alan G WassersteinAbstract:Complications associated with hemodialysis Vascular Access represent one of the most important sources of morbidity among ESRD patients in the United States today. In this study, new data on the magnitude and growth of Vascular Access-related hospitalization in the United States is presented, demonstrating that the costs of this morbidity will soon exceed $1 billion per yr. This study also reviews published literature on the morbidity associated specifically with native arteriovenous fistulae, polytetrafluoroethylene bridge grafts, and permanent central venous catheters. Next, new information on the changing patterns of Vascular Access type in the United States is presented, demonstrating the continuing evolution of medical practice away from the use of arteriovenous fistulae in favor of more reliance on synthetic bridge grafts. Based on these data, a discussion is provided of the tradeoffs among the most commonly available modalities of Vascular Access today. Although radial arteriovenous fistulae continue to represent the optimal Access modality, the appropriate roles for brachial arteriovenous fistulae, synthetic bridge grafts, and central venous catheters are less certain because of inadequate data on the long-term function of the first and the high rates of complications associated with the latter two. To reduce Vascular Access-related morbidity, strategies must be developed not only to prevent and detect appropriately early synthetic Vascular Access dysfunction, but to better identify the patients in a whom radial arteriovenous fistula is a viable clinical option.
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hemodialysis Vascular Access morbidity in the united states
Kidney International, 1993Co-Authors: Harold I Feldman, Philip J Held, John T Hutchinson, Eva Stoiber, Marguerite F HartiganAbstract:Hemodialysis Vascular Access morbidity in the United States. Extensive morbidity related to hemodialysis Vascular Access exists among endstage renal disease (ESRD) patients, but the risk factors for this morbidity have not been extensively studied. Medicare ESRD patient data were obtained from 1984, 1985, and 1986. Hospitalization for Vascular Access morbidity (ICD-996.1, 996.6, or 996.7) was analyzed among prevalent patients and, using survival analysis, among incident patients to assess sex, age, race, and underlying cause of renal failure as risk factors. We found that 15 to 16% of hospital stays among prevalent ESRD patients were associated with Vascular Access-related morbidity. Black race, older age, female sex, and diabetes mellitus as a cause of kidney failure were all independent risk factors for Access-related morbidity. The rate ratio comparing Blacks to Whites was 1.12 (95% C.I., 1.09, 1.16); > 64 years to 20 to 44 years, 1.53 (1.46, 1.59); men to women, 0.81 (0.79, 0.84); and diabetes to glomerulonephritis, 1.29 (1.24, 1.35). We conclude that hemodialysis Vascular Access malfunction causes much hospitalization among ESRD patients. Women, Blacks, the elderly, and diabetics appear to be at particularly high risk, and additional studies are needed to understand these patterns.
Marguerite F Hartigan - One of the best experts on this subject based on the ideXlab platform.
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hemodialysis Vascular Access morbidity in the united states
Kidney International, 1993Co-Authors: Harold I Feldman, Philip J Held, John T Hutchinson, Eva Stoiber, Marguerite F HartiganAbstract:Hemodialysis Vascular Access morbidity in the United States. Extensive morbidity related to hemodialysis Vascular Access exists among endstage renal disease (ESRD) patients, but the risk factors for this morbidity have not been extensively studied. Medicare ESRD patient data were obtained from 1984, 1985, and 1986. Hospitalization for Vascular Access morbidity (ICD-996.1, 996.6, or 996.7) was analyzed among prevalent patients and, using survival analysis, among incident patients to assess sex, age, race, and underlying cause of renal failure as risk factors. We found that 15 to 16% of hospital stays among prevalent ESRD patients were associated with Vascular Access-related morbidity. Black race, older age, female sex, and diabetes mellitus as a cause of kidney failure were all independent risk factors for Access-related morbidity. The rate ratio comparing Blacks to Whites was 1.12 (95% C.I., 1.09, 1.16); > 64 years to 20 to 44 years, 1.53 (1.46, 1.59); men to women, 0.81 (0.79, 0.84); and diabetes to glomerulonephritis, 1.29 (1.24, 1.35). We conclude that hemodialysis Vascular Access malfunction causes much hospitalization among ESRD patients. Women, Blacks, the elderly, and diabetics appear to be at particularly high risk, and additional studies are needed to understand these patterns.
