Primary Arteriovenous Fistula Research Articles

Outcomes of three types of native arteriovenous fistula in a single center.

To study the outcomes of three different types of native arteriovenous fistula (AVF), the distal (D: radial-cephalic), middle-arm (MA: radial-cephalic) and proximal (P: brachial-cephalic) AVF access creation for hemodialysis patients in a single center. An 8-year retrospective review, from 2006 to 2014, was conducted at a single institution in which the surgical outcomes for three different types of native AVF creation were reviewed. Preoperative duplex vein mapping was obtained in all patients to choose the best vein and site for access. There were 317 patients identified with 41 D-AVFs, 120 MA-AVFs and 156 P-AVFs. Younger patients with a lower Charlson's Index were more frequent in the D-AVF group (p = 0.02). Mean operating room time was 15 minutes longer for the MA-AVF group than the two others (p = 0.018). Early failure (thrombosis at 30-day), one-year patency, one-year primary AVF functional patency for the D-AVF, MA-AVF, and P-AVF groups were 2.4% (n = 1), 8% (n = 1), 3.8% (n = 6), (p = 0.14); 97.6% (n = 39), 99% (n = 117), 89% (n = 129), (p<0.001); 80.5% (n = 33), 75.8% (n = 91), and 61.5% (n = 96) (p<0.001), respectively. Reintervention for fistula maturation was required in 17% (n = 7), 23% (n = 28), and 24% (n = 38) (p<0.01). The one-year venipuncture hematoma and steal syndrome occurrences were 9.7% (n = 4), 6.7% (n = 8), 3.8% (n = 6) (p = 0.06); and 0%, 0% and 3.8% (n = 6) (p = 0.04), respectively. In case of failure of either MA-AVF or D-AVF, a P-AVF was always feasible as a second native AVF hemodialysis access. D-AVF is still the gold-standard access for hemodialysis. If D-AVF is not possible, MA-AVF should be always investigated before committing to a P-AVF.

Hypoproteinemia as a prognostic risk factor for arteriovenous fistula failure.

Any vascular access is of limited duration with many factors which influence survival in patients on chronic hemodialysis (HD). Hypoproteinemia as a marker of chronic illness is common among chronic HD patients. Our aim was to analyze the survival of the primary arteriovenous fistula (AVFs) and the risk factors which influence their patency and to test the hypothesis that patients with normal values of serum proteins have lower risk of AVF failure compared to patients with hypoproteinemia. Seven hundred thirty-four consecutive patients were included who underwent creation of an AVF. The patients were prospectively followed-up for 2 years. Only patients with AVF function after a month from its creation were analyzed. The patients were divided into two subgroups, with normal and low serum protein levels (<65 g/L). At follow-up 497 (67.7%) AVFs were still functional while 237 (32.3%) AVFs failed due to thrombosis or stenosis. Serum proteins and AVFs created on the forearm were positive predictors while diabetes was a negative predictor of longer AVF survival (P < 0.001; P = 0.003; P = 0.043). When comparing patients with normal and low serum protein levels (<65 g/L), mean survival time was significantly longer in patients with normal serum levels (P < 0.001). In this study, hypoproteinemia was an independent prognostic marker for AVF failure at 2 years. Hypoproteinemia, based on our results, is an independent, more sensitive and prognostic marker of possible vascular access failure than the presence of other common factors which influence shorter AVF survival.

Calcification in arteriovenous fistula blood vessels may predict arteriovenous fistula failure: a 5-year follow-up study.

Arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis. The impact of vascular calcification process on AVF survival remains unclear and results of several studies about this issue are controversial. In the light of the new knowledge about the different susceptibility for calcification process in different blood vessels, the aim of our study was to analyze whether the calcification of AVF-blood vessels may have an impact on AVF longevity. The study included 90 patients, 49 males and 41 females, all of them Caucasians, with a mean age 62±11years, on regular hemodialysis for more than 1 year with patent primary AVFs. Vascular calcification in AVF-blood vessels or in the anastomotic region was detected using X-ray examination. Calcification in AVF-blood vessels was found in 62% of patients. Binary logistic regression analysis demonstrated that male gender, presence of diabetes mellitus and longer duration of AVF before calcification determination were associated with calcification of AVF-blood vessels. Using a Cox proportional hazard model adjusted for these standardized predicted values revealed that patients with present AVF-blood vessels calcification had increased risk to develop AVF failure with a hazard rate of 3.42 (95% confidence interval 1.00-11.67; P=0.049). Calcifications of AVF-blood vessels are found frequently among dialysis patients and may jeopardize the survival of native AVF. We suggested the local X-ray as simple and valid method for detection of patients that are at risk for AVFs failure which should be monitored more closely.

VASCULAR ACCESS IN PATIENTS ON CHRONIC HEMODIALYSIS IN THE MOSCOW REGION: CURRENT STATE AND OUTLOOK

Background: The prevalence of chronic kidney disease (CKD) is annually growing worldwide. Stable functioning arteriovenous fistula (AVF) is one of the main prerequisites of survival for patients on chronic hemodialysis (HD). As a rule, available clinical guidelines for creation and maintenance of HD vascular access do not give a clear answer to some important questions. We have summarized and analyzed our experience of the creation and maintenance of the vascular access. Aim: To analyze the results of the creation and maintenance of vascular access in a large population of patients on chronic HD (in the Moscow Region). Materials and methods: We analyzed the results of 3837 surgeries for creation and reconstruction of the vascular access in 1862 patients, performed from 2012 to 2016. Results: The CKD stage 5D incidence has increased from 239 to 391 over the last three years. Currently, 2204 patients are followed up and receiving treatment in 38 outpatient centers. Almost one half of all interventions, 43.5% (1668/3837), has been performed to create AVF. Only one third, i.e. 33% (1266/3837) of them was de novo operations, whereas 10.5% (403/3837) were done to create a new AVF in HD patients after thrombosis of the existing AVF. 15.4% (590/3837) of the interventions were performed for AVF reconstruction, 4% (154/3837) for AVF closure after successful kidney transplantation, 3.2% (121/3837) for creation of AVF with vascular graft, 3% (115/3837) for thrombectomy from the graft, 14.6% (559/3837) to implant a permanent central venous catheter (CVC), and 13.6% (520/3837) for placement of a temporary CVC. 54.4% (1012/1862) of the patients had their functional AVF, 2.2% (41/1862) had a vascular graft at the beginning of HD, and one year later, there were 73.8% (1152/1561) and 5.3% (83/1561) of such patients, respectively. The type of vascular access at the start of HD strongly depended on the cause of CKD. 60.4% (192/318) of patients with polycystic kidney disease and 65.1% (181/278) with systemic disease or cancer started HD with the CVC. Oneyear survival of patients who started HD with AVF, who started HD with CVC and switched to AVF, and those who initiated and continued HD with CVC only, was 87.5% (95% confidence interval [CI] 83.5– 90.6), 79.6% [95% CI 72.3–82.5], and 66.4% (95% CI 57–74.2), respectively. The 5-year survival in these groups was 61% (95% CI 51.8–71.9), 53.9% (95% CI 42.5–67), and 31.6% (95% CI 21.4–41.4), respectively. At one year, primary and secondary AVF patency amounted to 77.2% (95% CI 71.7–81.8) and 87% (95% CI 83.7–89.7), respectively, at 5 years 34.1% (95% CI 27.8–40.5) and 60.9% (95% CI 56.4– 65.1), respectively. Conclusion: A more detailed analysis is necessary to identify risk factors for complications of the vascular access and to optimize approaches to its creation and reconstruction. An effective way to achieve this goal is to establish a local registry of CKD patients.

Effects of far infrared therapy on arteriovenous fistulas in hemodialysis patients: a meta-analysis

Background: Far infrared (FIR) therapy may have a beneficial effect on maturity and function of arteriovenous fistulas (AVFs) in hemodialysis (HD) patients. Therefore, we performed this pooled analysis to assess the protective effects of FIR therapy in HD patients.Methods: The randomized controlled trials (RCTs) and quasi-RCTs of FIR therapy for HD patients were searched from multiple databases. Relevant studies were screened according to the predefined inclusion criteria. The meta-analyses were performed using RevMan 5.2 software (The Cochrane Collaboration, Oxford, UK).Results: Meta-analysis showed that FIR therapy could significantly increase the vascular access blood flow level (MD, 81.69 ml/min; 95% CI, 46.17–117.21; p < .001), AVFs diameter level (MD, 0.36 mm; 95% CI, 0.22–0.51; p < .001), and the primary AVFs patency (pooled risk ratio = 1.24; 95% CI, 1.12–1.37, p < .001). In addition, therapy with FIR ray radiation could decrease AVFs occlusion rates (pooled risk ratio = 0.20; 95% CI, 0.08–0.46; p < .001) and the level of needling pain (pooled risk ratio = 0.08; 95% CI, 0.06–0.10, p < .001).Conclusions: FIR therapy can reduce AVFs occlusion rates and needling pain level, while significantly improve the level of vascular access blood flow, AVFs diameter and the primary AVFs patency.

Creation of Primary Arterio-Venous Fistula

Creation of Primary Arterio-Venous Fistula

Strategies for Hemodialysis Access: A Vascular Surgeon’s Perspective

Problems related to hemodialysis access are a significant cause of morbidity and mortality in patients with end-stage renal disease. Physicians of all specialties who are involved in the placement and maintenance of vascular access for hemodialysis must have a long-term strategy for sequential placement of autogenous fistulas, transpositions, and prosthetic grafts to preserve access sites and to avoid long-term use of tunneled dialysis catheters. The Fistula First and KDOQI initiatives have provided strategies and algorithms for access placement in patients with chronic kidney disease. Preservation of veins should begin before dialysis access is necessary to achieve the goal of creating a primary arteriovenous (AV) fistula or transposition suitable for cannulation when dialysis is initiated. Prosthetic and biologic grafts offer reasonable alternatives when autogenous access is not feasible. Newer graft materials and conduits are under evaluation to improve long-term outcomes. Use of tunneled dialysis catheters should be discouraged and they should be considered a last resort for long-term access. We present a strategy from the perspective of a vascular surgeon for the sequential placement of AV fistulas, venous transpositions, and AV grafts in these challenging patients. We also discuss specific concerns regarding hemodialysis access in difficult patient populations such as the elderly patient and the morbidly obese patient.

Effect of ethnicity and socioeconomic status on vascular access provision and performance in an urban NHS hospital.

BackgroundThe aim of this study was to examine the effect of ethnicity, socioeconomic group (SEG) and comorbidities on provision of vascular access for haemodialysis (HD).MethodsThis was a retrospective review of two databases of HD sessions and access operations from 2003–11. Access modality of first HD session and details of transplanted patients were derived from the renal database. Follow-up was until 1 January 2015. Primary failure (PF) was defined as an arteriovenous fistula (AVF) used for fewer than six consecutive dialysis sessions. AVF survival was defined as being until the date the AVF was abandoned. Ethnicity was coded from hospital records. SEG was calculated from postcodes and 2011 census data from the Office of National Statistics. Comorbidities were calculated with the Charlson Comorbidity Index.ResultsFive hundred incident patients started chronic HD in the study period. Mode of starting HD was not associated with ethnicity (P = 0.27) or SEG (P = 0.45). Patients from ethnic minorities were younger when starting dialysis (P < 0.0001). Some 928 AVF patients' first AVF operations were analysed: 68% Caucasian, 26% Asian and 6% Afro-Caribbean. Half were in the most deprived SEG and 11% in the least deprived SEG. PF did not differ by ethnicity (P = 0.29), SEG (P = 0.75) or comorbidities (P = 0.54). AVF survival was not different according to ethnicity (P = 0.13) or SEG (P = 0.87). AVF survival was better for patients with a low comorbidity score (P = 0.04). The distribution of transplant recipients by ethnic group and SEG was similar to the distributions of all HD starters.ConclusionEthnicity and socioeconomic group had no effect on mode of starting HD, primary AVF failure rate or AVF survival. Ethnic minorities were younger at start of dialysis and at their first AVF operation.

A novel factor for primary arteriovenous fistula failure: hyperinsulinism

Introduction: Dysfunction of vascular access is an important reason of morbidity for dialysis patients and it is a major factor affecting the economical burden of hemodialysis. The preferred type of vascular access is creation of an arteriovenous fistula (AVF). However, the problem of fistula maturation rate is still a challenge. Herein, we tried to search the role of hyperinsulinism and insulin resistance as a new predictor of primary AVF failure (pAVFF) that may be a cause of intimal damage.Methods: We included 119 patients (73 male and 46 female) with a diagnosis of end-stage renal disease (ESRD) who had undergone an AVF operation by a vascular surgeon. The AVF was examined for presence of thrill on the first postoperative day. A successful cannulation with two fistula needles with a blood flow of 250 mL/min for at least one complete dialysis session, after 4 weeks of AVF surgery was defined as functioning access. Insulin resistance in our patients was determined by the standard homeostasis model assessment (homa-IR). A logistic-regression analysis was performed to investigate the independent factors related with pAVFF.Findings: Detection of pAVFF occurred in 27 (22.7%) patients. The presence of thrill, amount of daily proteinuria, insulin levels, homa-IR, and serum albumin levels were found to be significantly different between patients with fistula failure and those without pAVFF. The logistic-regression analysis of preoperative factors revealed the following OR (odds ratio) and 95% CI values: homa-IR 1.205 (1.063–1.366) (p = 0.004), serum albumin 0.398 (0.178–0.892) (p = 0.025), and the amount of daily proteinuria 1.307 (1.012–1.688) (p = 0.041). Even after addition of the presence of postoperative thrill on AVF, which was a postoperative strong clinical factor to the analysis, mean homa-IR and mean serum albumin continued to be independent predictors of pAVFF.Discussion: Insulin resistance or hyperinsulinism may be a significant cause of pAVFF, which emphasizes the role of endothelium in fistula dysfunction.

Outcomes of primary arteriovenous fistulas in patients older than 70 years

The population of elderly hemodialysis patients is increasing, yet the most suitable approach for providing permanent hemodialysis access remains unclear. Here we report outcomes using an approach aimed predominantly at creating radiocephalic (RC) fistulas. A single-center retrospective cohort study was performed in which access outcomes for primary arteriovenous fistulas created between January 1, 2005, and December 31, 2012, in patients aged 70years or older were compared. During the study period, 204 RC, 1 brachiobasilic, and 9 brachiocephalic (BC) primary fistulas were created initially for patients requiring dialysis. Immediate failure rates for RC fistulas were lower than for BC fistulas but not significantly so (12% vs 22%; Fisher's exact text, P= .319). One-year primary and secondary patency for RC fistulas was54% and 66%, respectively, and similar for those created in patients between 70 and 80years old and in those olderthan 80years. The secondary patency rate at 1year for RC fistulas using cephalic vein of diameter<2.5mm waslower than for fistulas created with cephalic vein >2.5mm (49% vs 72%; log-rank test, P= .005). Creation of a BCfistula was associated with a significantly higher incidence of steal syndrome than with an RC fistula (10% vs 2%; Fisher's exact text, P= .009). RC fistulas formed in the elderly carry a lower risk of steal syndrome than BC fistulas and offer the potential for further revision surgery, such that acceptable secondary patency is achieved for RC fistulas formed using even small (<2.5mm) cephalic veins.

Predictors of radio-cephalic arteriovenous fistulae patency in an Asian population.

To identify predictors of arteriovenous fistula (AVF) patency in Asian patients with autogenous radio-cephalic arteriovenous fistula (RCAVF). Retrospective review of 436 RCAVFs created between 2009 and 2013. Predictors of patency were identified with univariate and multivariate analysis. Kaplan-Meier survival analysis and log-rank test were used to calculate patency rates. Overall secondary patency rate was 72% at 12 months, 69% at 24 months, 58% at 36 months, 57% at 48 months, 56% at 60 months and 54% at 72 months. Univariate analysis showed that factors which predict for patency include male gender (p = 0.003), good diabetic control (p = 0.025), aspirin use (p = 0.031), pre-dialysis status (p = 0.037), radial artery diameter (p = 0.029) and non-calcified radial arteries (p = 0.002). Age (p = 0.866), cephalic vein diameter (p = 0.630) and surgeon grade (p = 0.472) did not predict for primary AVF failure. Multivariate analysis revealed the male gender to be an independent predictor for patency (odds ratio 1.99, p = 0.01). Subset analysis showed a significantly larger average radial artery diameter of 2.3 mm amongst males, as compared to 1.9 mm amongst females (p = 0.001) and no statistical difference in the average cephalic vein diameter. Within our Asian study population, 12-month patency rate of RCAVF is 72%, 69% at 24 months, 58% at 36 months, 57% at 48 months, 56% at 60 months and 54% at 72 months. Male gender is an independent predictor for RCAVF patency. In females or patients with calcified radial arteries, a more proximal AVF should be considered.

Comparison of Nonpenetrating Titanium Clips versus Continuous Polypropylene Suture in Dialysis Access Creation

Nonpenetrating titanium surgical clips (clips) offer a theoretical advantage of inducing less intimal hyperplasia at an anastomosis because of less endothelial injury. Whether this translates into improved outcomes when used in the creation of arteriovenous fistulas (AVFs) remains unclear. We sought to compare the maturation, patency, and failure rates of anastomoses created using traditional continuous polypropylene suture and clips. All primary AVF created at a single Veterans Administration Medical Center were reviewed over a 6-year period. Anastomoses were created with either clips or suture based on surgeon preference. Patient characteristics and surgical outcomes were collected. Comparisons were made between the 2 groups. Over a 6-year period, 334 fistulas were created (29% suture and 71% clips) in 326 patients. The mean age was 64.8 ± 11 years with 98% males. Comorbidities included diabetes (70%), hypertension (96.1%), and tobacco use (52.9% previous or current). Approximately half the patients were predialysis. Comparison of patient characteristics showed no differences between the suture and clip groups. There was no significant difference in maturation rate (suture 79% versus clips 72%, P = 0.25), median time to maturation (suture 62 ± 35 versus clips 71 ± 13 days, P = 0.07), 1 year primary patency rate (suture 37.4% versus clips 39.6, P = 0.72), 1 year assisted primary patency rate (suture 82.4% versus clips 76.3%, P = 0.31), or overall failure rates (suture 62% versus clips 58%, P = 0.56). Median time to initial failure or reintervention was not significantly different in the clip group (suture 615 [range, 239-991] versus clips 812 [range, 635-989] days, P = 0.72). Compared to traditional polypropylene suture creation of upper extremity AVFs, nonpenetrating clips had equivalent maturation, 1-year patency, and overall failure rates. Neither clips nor suture offers any clear advantage in the creation of AVF.

Outcomes for forearm and upper arm arteriovenous fistula creation with the transposition technique

To study the outcomes of three different types of arteriovenous fistula (AVF) transpositions (forearm cephalic vein transposition [FACVT], upper arm cephalic vein transposition [UACVT], and upper arm basilic vein transposition [UABVT]) for dialysis patients in a single center. A 6-year retrospective review, from 2006 to 2012, was conducted at a single institution in which the surgical outcomes for three different types of AVF transposition were reviewed. Preoperative duplex vein mapping was obtained in all patients to choose the best vein for access. There were 165 patients identified with 77 FACVTs, 52 UACVTs, and 36 UABVTs. Primary access maturation rates for the FACVT, UACVT, and UABVT groups were 86%, 90%, and 97%, respectively (P = .19). All transposed, matured primary AVFs were used after a mean of 9.9 weeks, without additional intervention. Primary 1-year patency for the FACVT, UACVT, and UABVT groups were 63%, 61%, and 70%, respectively (P = .71). Primary assisted 1-year patency for the FACVT, UACVT, and UABVT groups were 93%, 93%, and 100%, respectively (P > .999). Mean operating room times and time to intervention were not significantly different between the groups. The postoperative hematoma rate was 2% and wound infection rate was 2%. Multivariate analysis indicated no significant predictors of time to failure (P > .05). With low primary failure rates, reduced need for secondary interventions before maturation, and 1-year primary assisted patency rates in excess of 93%, our study showed that the transposition technique, in our experience, is superior to previously published literature in hemodialysis access creation.

Patient-Centered Dialysis Care: Depression, Pain, and Quality of Life.

Remarkable advancements have been made in the provision of chronic dialysis therapy since its inception decades ago. A series of studies inform current dialysis dosing recommendations, while advancements in strategies to treat mineral and bone disease, acid-base and electrolyte disturbances, and anemia have facilitated the management of these well-recognized complications of ESRD. The collective result has been a model of chronic dialysis care focused principally on the achievement of metabolic and dialysis-related targets. In fact, guidelines such as the Kidney Disease Outcomes Quality Initiative put forth by the National Kidney Foundation recommend metrics that characterize successful dialysis care, including the attainment of specific solute clearance targets; maintenance of hemoglobin, calcium, phosphorous, and parathyroid hormone levels within target ranges; and the preferred use of primary arteriovenous fistulae for vascular access. This focus on serologic and dialysis-specific outcomes has helped renal providers manage the biochemical effects related to the loss of kidney function and has reduced ESRD-related morbidity and mortality. Yet, absent from this model of care is an emphasis on the treatment of bothersome symptoms and the impact of such treatment on quality of life (QOL). Among the many symptoms that affect patients on chronic dialysis, depression and pain are particularly common, strongly associated with decrements in QOL, and potentially treatable. This review discusses key research findings and unanswered questions pertaining to the prevalence, significance, and treatment of depression and pain and the effect of such treatment on QOL in patients dependent on chronic dialysis, with the broad goal of incorporating symptom management strategies into a paradigm of patient-centered dialysis care.

Impact of a preoperative evaluation on the outcomes of an arteriovenous fistula.

PurposeThe aim of this study was to determine the possible predictors of primary arteriovenous fistula (AVF) failure and examine the impact of a preoperative evaluation on AVF outcomes.MethodsA total of 539 patients who underwent assessment for a suitable site for AVF creation by physical examination alone or additional duplex ultrasound were included in this study. Demographics, patient characteristics, and AVF outcomes were analyzed retrospectively.ResultsAVF creation was proposed in 469 patients (87.0%) according to physical examination alone (351 patients) or additional duplex ultrasound (118 patients); a prosthetic arteriovenous graft was initially placed in the remaining 70 patients (13.0%). Although the primary failure rate was significantly higher in patients assessed by duplex ultrasound (P = 0.001), ultrasound information changed the clinical plan, increasing AVF use for dialysis, in 92 of the 188 patients (48.9%) with an insufficient physical examination. Female sex and diabetes mellitus were risk factors significantly associated with primary AVF failure. Because of different inclusion criteria and a lack of adjustment for baseline differences, Kaplan-Meier survival analysis showed better AVF outcomes in patients assessed by physical examination alone; an insufficient physical examination was the only risk factor significantly associated with AVF outcomes.ConclusionRoutine use of duplex ultrasound is not necessary in chronic kidney disease patients with a satisfactory physical examination. Given that female gender and diabetes mellitus are significantly associated with primary AVF failure, duplex ultrasound could be of particular benefit in these subtypes of patients without a sufficient physical examination.

Abstract 16581: Pre-existing Venous Intimal Hyperplasia Explains Post-operatory Neointima Growth but Fails to Predict Arteriovenous Fistula Failure: The Matched-pair Cohort Study

Introduction: Arteriovenous fistulae (AVF) failure is the most common complication in hemodialysis patients. It compromises dialysis treatment, worsens patients’ quality of life and increases the medical costs associated with the maintenance of vascular accesses. There is a belief that AVF failure is mainly due to occlusive neointimal hyperplasia. This study assesses for the first time the impact of pre-existing venous intimal hyperplasia on post surgical neointima development and AVF function (patency). Methods and Results: Fifty one patients undergoing two-stage brachiobasilic AVF creation at the University of Miami Hospital and Jackson Memorial Health System were enrolled. Matched pair tissue samples were taken from each patient. The proximal basilic vein was procured during vascular access creation while the second biopsy was obtained at the time of AVF transposition for its superficialization. Tissues were rapidly formalin-fixed and cross-sectioned for histomorphometric measurements of the neointima and media areas. Pre-existing intima hyperplasia was persistent among most basilic veins with neointima to media ratios (N/M) ranging between 0.075 and 0.709 (mean: 0.289). The neointimal lesion size experienced a 2.26 fold increased during fistula maturation (p&lt;0.0001, paired t-test). A general linear regression model controlled for multiple baseline covariates revealed the existing positive correlation between the venous intima hyperplasia and the later neointimal growth in the corresponding AVF (B=0.728, p=0.0311). Unexpectedly, the venous N/M ratio failed to predict primary AVF patency using a COX proportional hazard model that included 9 baseline-covariates (age, gender, time between surgeries, diabetes, previous AVF and catheter, statins, anti-platelet and anti-hypertensive drugs). Conclusions: While pre-existing intimal hyperplasia correlates with the size of the post-operatory neointima in the AVF as revealed in this matched-pair cohort study, it has no impact on the future AVF function and success.

The reasons for the failure of the primary arteriovenous fistula surgery in patients with end-stage renal disease.

To analyze the reasons for the failure of the primary arteriovenous fistula surgery and explore preventive measures. A total of 819 patients with end-stage renal disease were enrolled in the study. Autologous arteriovenous fistula surgery was performed on all patients. Their clinical data of hemoglobin (HB), albumin (ALB), cholesterol (CHOL), parathyroid hormone (PTH), blood glucose and blood pressure were collected before surgery, while the diameters of the radial artery and cephalic vein were measured by ultrasound. The operations in 742 patients were successful, but failed in 77 cases (accounting for 7.07%). The failure group was significantly older (61.3 ± 13.4 years) than the successful group (45.6 ± 11.2 years). The ratio of diabetes 36 (46.8%) and hypertension 20 (26.0%) was significantly higher in the failure group than in the successful group, respectively 235 (31.7%) and 145 (19.5%). The patients with blood pressure below 120/70 mm Hg had a higher risk of failed surgery (36.4%) than those with blood pressure above 120/70 mm Hg (9.16%). The cephalic vein and radial artery diameter were significantly smaller in the failure group (1.35 ± 0.64 mm, 2.13 ± 0.81 mm) than in the successful group (1.98 ± 0.47 mm, 2.47 ± 0.74 mm); [corrected] the PTH levels in the failure group were significantly higher (782.39 ± 423.85) than in the successful group (378.83 ± 352.21). The autogenous arteriovenous fistula surgery failure highly correlated with the patient's age, blood pressure, the primary disease and the vessel diameter. In addition, the PTH levels had a certain correlation with the failure of the fistula surgery.

The Omega-3 fatty acids (Fish Oils) and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED) study: the updated final trial protocol and rationale of post-initiation trial modifications.

BackgroundThe FAVOURED study is an international multicentre, double-blind, placebo-controlled trial which commenced recruitment in 2008 and examines whether omega-3 polyunsaturated fatty acids (omega-3 PUFAs) either alone or in combination with aspirin will effectively reduce primary access failure of de novo arteriovenous fistulae (AVF) in patients with stage 4 and 5 chronic kidney disease. Publication of new evidence derived from additional studies of clopidogrel and a high screen failure rate due to prevalent aspirin usage prompted an updated trial design.Methods/designThe original trial protocol published in 2009 has undergone two major amendments, which were implemented in 2011. Firstly, the primary outcome ‘early thrombosis’ at 3 months following AVF creation was broadened to a more clinically relevant outcome of ‘AVF access failure’; a composite of thrombosis, AVF abandonment and cannulation failure at 12 months. Secondly, participants unable to cease using aspirin were allowed to be enrolled and randomised to omega-3 PUFAs or placebo. The revised primary aim of the FAVOURED study is to test the hypothesis that omega-3 PUFAs will reduce rates of AVF access failure within 12 months following AVF surgery. The secondary aims are to examine the effect of omega-3 PUFAs and aspirin on the individual components of the primary end-point, to examine the safety of study interventions and assess central venous catheter requirement as a result of access failure.DiscussionThis multicentre international clinical trial was amended to address the clinically relevant question of whether the usability of de novo AVF at 12 months can be improved by the early use of omega-3 PUFAs and to a lesser extent aspirin. This study protocol amendment was made in response to a large trial demonstrating that clopidogrel is effective in safely preventing primary AVF thrombosis, but ineffective at increasing functional patency. Secondly, including patients taking aspirin will enrol a more representative cohort of haemodialysis patients, who are significantly older with a higher prevalence of cardiovascular disease and diabetes which may increase event rates and the power of the study.Trial registrationAustralia & New Zealand Clinical Trial Register (ACTRN12607000569404)

Pre-existing Arterial Micro-Calcification Predicts Primary Unassisted Arteriovenous Fistula Failure in Incident Hemodialysis Patients.

Vascular access micro-calcification is a risk factor for cardiovascular morbidity and mortality in hemodialysis (HD) patients but its influence on vascular access patency is still undetermined. Our study aimed to determine the impact of arterial micro-calcification (AMiC) on the patency of vascular access in HD patients. One-hundred fourteen HD patients receiving arteriovenous fistula (AVF) operation were included in this study. During the operation, we obtained partial arterial specimen and performed pathological examination by von Kossa stain to identify AMiC. We compared primary unassisted AVF failure within 1 year between positive and negative AMiC groups, and performed Cox regression analysis for evaluating risk factor of AVF failure. The incidence of AMiC was 37.7% and AVF failure occurred in 45 patients (39.5%). The AVF failure rate within 1 year was greater in the positive AMiC group than those in the negative AMiC group (53.5% vs. 31.0%, p = 0.02). Kaplan-Meier analysis showed that the positive AMiC group had a lower AVF patency rate than the negative AMiC group (p = 0.02). The presence of AMiC was an independent risk factor for AVF failure. In conclusion, preexisting AMiC of the vascular access is associated with primary unassisted AVF failure in incident HD patients.

Predictive parameters of arteriovenous fistula functional maturation in a population of patients with end-stage renal disease.

IntroductionWith increasing numbers of patients diagnosed with ESRD, arteriovenous fistula (AVF) maturation has become a major factor in improving both dialysis related outcomes and quality of life of those patients. Compared to other types of access it has been established that a functional AVF access is the least likely to be associated with thrombosis, infection, hospital admissions, secondary interventions to maintain patency and death.AimStudy of demographic factors implicated in the functional maturation of arteriovenous fistulas. Also, to explore any possible association between preoperative haematological investigations and functional maturation.MethodsWe performed a retrospective chart review of all patients with ESRD who were referred to the vascular service in the University Hospital of Limerick for creation of vascular access for HD. We included patients with primary AVFs; and excluded those who underwent secondary procedures.ResultsOverall AVF functional maturation rate in our study was 53.7% (52/97). Female gender showed significant association with nonmaturation (P = 0.004) and was the only predictor for non-maturation in a logistic regression model (P = 0.011). Patients who had history of renal transplant (P = 0.036), had relatively lower haemoglobin levels (P = 0.01) and were on calcium channel blockers (P = 0.001) showed better functional maturation rates.ConclusionFemale gender was found to be associated with functional non-maturation, while a history kidney transplant, calcium channel-blocker agents and low haemoglobin levels were all associated with successful functional maturation. In view of the conflicting evidence in the literature, large prospective multi-centre registry-based studies with well-defined outcomes are needed.