Arteriovenous Fistula Maturation Failure Research Articles

Superoxide in AVF dysfunction: a new target for intervention

an adequately functioning vascular access is an absolute requisite for patients receiving hemodialysis. Among the three currently available (fistulae, grafts, and tunneled catheters) vascular accesses, the arteriovenous fistula (AVF) is considered the “gold standard” and is the most common mode

Back to the Future: How Biology and Technology Could Change the Role of PTFE Grafts in Vascular Access Management

Although the arteriovenous fistula (AVF) is the preferred mode of dialysis vascular access, AVF maturation failure remains a huge clinical problem, often resulting in a prolonged duration of use of tunneled dialysis catheters. In contrast, polytetrafluoroethylene (PTFE) grafts do not suffer from early failure, but have significant problems with later stenosis and thrombosis. This review will initially summarize the pathology and pathogenesis of PTFE graft dysfunction and will then use this as a basis for describing some novel therapies, which may have the potential to reduce PTFE graft dysfunction. Finally, we will emphasize that the introduction of such therapies could be an important first step toward individualizing overall vascular access care.

Longitudinal Assessment of Hemodynamic Endpoints in Predicting Arteriovenous Fistula Maturation

Arteriovenous fistula (AVF) nonmaturation is currently a significant clinical problem; however, the mechanisms responsible for this have remained unanswered. Previous work by our group and others has suggested that anatomical configuration and the corresponding hemodynamic endpoints could have an important role in AVF remodeling. Thus, our goal was to assess the longitudinal (temporal) effect of wall shear stress (WSS) on remodeling process of AVFs with two different configurations. The hypothesis is that early assessment of hemodynamic endpoints such as temporal gradient of WSS will predict the maturation status of AVF at later time points. Two AVFs with curved (C-AVF) and straight (S-AVF) configurations were created between the femoral artery and vein of each pig. Three pigs were considered in this study and in total six AVFs (three C-AVF and three S-AVF) were created. The CT scan and ultrasound were utilized to numerically evaluate local WSS at 20 cross-sections along the venous segment of AVFs at 2D (D: days), 7D, and 28D postsurgery. These cross-sections were located at 1.5 mm increments from the anastomosis junction. Local WSS values at these cross-sections were correlated with their corresponding luminal area over time. The WSS in C-AVF decreased from 22.3 ± 4.8 dyn/cm(2) at 2D to 4.1 ± 5.1 dyn/cm(2) at 28D, while WSS increased in S-AVF from 13.0 ± 5.0 dyn/cm(2) at 2D to 36.7 ± 5.3 dyn/cm(2) at 28D. Corresponding to these changes in WSS levels, luminal area of C-AVF dilated (0.23 ± 0.14 cm(2) at 2D to 0.87 ± 0.14 cm(2) at 28D) with attendant increase in flow rate. However, S-AVF had minimal changes in area (0.26 ± 0.02 cm(2) at 2D to 0.27 ± 0.03 cm(2) at 28D) despite some increase in flow rate. Our results suggest that the temporal changes of WSS could have significant effects on AVF maturation. Reduction in WSS over time (regardless of initial values) may result in dilation (p < 0.05), while increase in WSS may be detrimental to maturation. Thus, creation of AVFs in a specific configuration which results in a decline in WSS over time may reduce AVF maturation failure.

Prevalence of Arteriovenous Fistulas in Incident Hemodialysis Patients: Correlation With Patient Factors That May Be Associated With Maturation Failure

Lok et al previously reported a risk equation for arteriovenous fistula (AVF) maturation failure. It is unclear whether this model or a more comprehensive model correlates with incident AVF use in the US hemodialysis population. Cross-sectional study. 195,756 adult patients initiating outpatient hemodialysis therapy in the United States between July 1, 2005, and December 31, 2009, with 6 months or more prior nephrology care. Patient characteristics (age, peripheral vascular disease, coronary artery disease, and race) populating the AVF maturation failure risk equation and other demographic and clinical variables from the Centers for Medicare & Medicaid Services (CMS) Medical Evidence Report (CMS 2728). AVF use at first outpatient dialysis treatment as recorded on the CMS 2728. Using the risk categories defined by Lok et al, AVF use varied from 19.0% (very high risk) to 25.6% (low risk). In a model using only these risk categories, logistic regression showed lower ORs for moderate-, 0.90 (95% CI, 0.88-0.93); high-, 0.80 (95% CI, 0.78-0.83); and very high-risk patients, 0.68 (95% CI, 0.63-0.73) compared with low risk. In the expanded model, odds were lower for women, blacks, Hispanics, age older than 85 years, diabetes, peripheral vascular disease, congestive heart failure, other cardiac disease, and underweight. Odds were higher for hypertension, overweight, obesity, 12 months or more nephrologist care, most insurance types, and each successive year after 2005. Despite associations, the C statistic for the expanded model was 0.64. This analysis is limited by lack of access creation history before dialysis therapy initiation and minimal external validation of CMS 2728 data. Clinical risk factors identified by Lok and expanded in this analysis have limited ability to predict incident AVF use. Even patients judged at highest risk can have successful AVF construction and initiate dialysis therapy through a functioning AVF.