Primary Arteriovenous Fistula Research Articles

The outcome of the primary vascular access and its translation into prevalent access use rates in chronic haemodialysis patients.

BackgroundThe American Fistula First Breakthrough Initiative currently aims for a 66% arterio-venous fistula (AVF) rate, while in the UK, best practice tariffs target AVF and arterio-venous graft (AVG) rates of 85%. The present study aims to assess whether these goals can be achieved.MethodsWe conducted a retrospective cohort study on patients who initiated haemodialysis from 1995 to 2006. Outcomes were the final failure-free survival of the first permanent access and the type of second access created. Prevalent use rates for the access types were calculated on the 1st January of each year for the second half of the study period.ResultsTwo hundred and eleven out of 246 patients (86%) received an AVF, 16 (6%) an AVG and 19 (8%) a permanent catheter (PC) as the first permanent access. Eighty-six (35%) patients had final failure of the primary access. One- and 3-year final failure-free survival rates were 73 and 65% for AVF compared with 40 and 20% for AVG and 62 and 0% for PC, respectively. In patients with primary AVF, female sex {hazard ratio (HR) 2.20 [confidence interval (CI) 1.29–3.73]} and vascular disease [HR 2.24 (CI 1.26–3.97)] were associated with a poorer outcome. A similar trend was observed for autoimmune disease [HR 2.14 (CI 0.99–4.65)]. As second accesses AVF, AVG and PC were created in 47% (n = 40), 38% (n = 33) and 15% (n = 13). The median prevalent use rate was 80.5% for AVF, 14% for AVG and 5.5% for PC.ConclusionsThe vascular access targets set by initiatives from the USA and UK are feasible in unselected haemodialysis patients. High primary AVF rates, the superior survival rates of AVFs even in patient groups at higher risk of access failure and the high rate of creation of secondary AVFs contributed to these promising results.

Metabolic Syndrome: A Marker for Decreased Cumulative Patency Among Patients Undergoing Arteriovenous Fistula Placement

The natural history of patients with metabolic syndrome (MetS) undergoing arteriovenous fistula placement is unknown. MetS has previously been found as a risk factor for poor outcomes for vascular surgery patients undergoing other interventions. The aim of this is study is to describe the outcomes of MetS patients undergoing primary arteriovenous fistula placement. The medical records of all patients undergoing arteriovenous fistula placement between 2004 and 2009 at the VA Connecticut Healthcare system were reviewed (n = 122). Survival, primary patency, and secondary patency were evaluated using Gehan-Breslow test for survival. MetS was defined as the presence of three or more of the following: blood pressure ≥130/≥90 mmHg, triglycerides ≥150 mg/dL, high-density lipoproteins (HDL) ≤50 mg/dL for women and ≤40 mg/dL for men, body mass index (BMI) ≥30 kg/m2, and fasting blood glucose ≥110 mg/dL. A total of 122 patients underwent primary arteriovenous fistula placement, and 75 (61%) were identified to have MetS. The distribution of MetS factors among all patients were 120 (98%) were hypertensive, 70 (57%) were diabetic, 51 (42%) had elevated triglycerides; 75 (61%) had decreased HDL, and 46 (38%) had an elevated BMI. 55 (45%) of patients were currently receiving hemodialysis. The mean age of patients was 65 years. The mean length of follow-up was 2.9 years. The forearm was the site of fistula placement in 76 (62%) of patients; no difference existed between groups (39%, MetS; 36%, No MetS; P = .78). The median time to primary failure was 0.57 years for all patients (0.76 years, No MetS; 0.47 years, MetS; P = .11). Secondary patency was 50% at 1.28 years for all patients (1.72 years, No MetS; 0.72 years, MetS; P = .01). Median survival duration for all patients was 4.7 years (5.2 years, No MetS; 4.5 years, MetS; P = .03). MetS is prevalent among patients undergoing arteriovenous fistula placement. Patients with MetS have equivalent primary patency rates, however, their survival and cumulative patency rates are significantly lower compared with those patients without MetS. MetS should be considered as a significant risk factor for patients undergoing arteriovenous fistula placement.

Outcomes of Secondary Compared to Primary Autogenous Haemodialysis Arteriovenous Fistulae, a Five Year Survey

Aims: We examined the outcome and patency rates of secondary in comparison to primary arteriovenous fistulae (AVF) in a cohort of haemodialysis (HD) patients. Study design: A retrospective review of native AVFs formed in a five year period. Place and Duration of Study: Department of Renal and Vascular Medicine Hull and East Yorkshire Hospitals NHS Trust, East Yorkshire between December 2000 to December 2005. Methodology: HD patients who had autogenous AVF created in a single centre over a 5 year period. 346 patients (mean age 61±16 years, 35.8% females, 29.2% diabetics) were included. Data on type of AVF, demographics, co-morbidities, immediate outcome and subsequent vascular access (VA) patency were collected. Results: 463 AVF were created (304 radiocephalic (RC) and 159 brachiocephalic (BC)), of which 160 (34.6%) were secondary procedures. There was no significant difference in the primary failure rate (PFR) of primary and secondary AVFs (38.9 vs. 37.5% respectively). Primary RC fistulae had a higher failure rate in comparison to BC fistulae (42.6 and 21.3%, respectively, p = 0.002, OR 2.7; CI: 1.4-5.3). There was a higher PFR of AVF among females (primary access: 47 vs. 33% in males, p = 0.028; OR 1.7; 95% CI: 1.1-2.8; secondary access: 53 vs. 27%, p= 0.002; OR 3.1; 95% CI: 1.5-6). There was no difference in PFR of primary and secondary fistulae among Research Article British Journal of Medicine & Medical Research, 2(1): 62-73, 2012 63 diabetics and non-diabetics. Conclusion: The primary success rate of secondary autogenous AVFs is similar to primary fistulae. Females have a higher rate of fistula failure.

Relationship between preoperative radial artery and postoperative arteriovenous fistula blood flow in hemodialysis patients

It is recommended that arteriovenous fistula (AVF) blood flow should be more than 425 ml/min before cannulation. However, the relationship between preoperative radial artery flow (RAF) and postoperative AVF blood flow has still not been examined. Sixty-one patients with end-stage kidney disease (ESKD) were examined. They had an AVF prepared at Juntendo University Hospital from July 2006 through August 2007. Preoperative RAF and postoperative AVF blood flows were measured by ultrasonography. AVF blood flow gradually increased after the operation. AVF blood flow was significantly correlated with preoperative RAF. When preoperative RAF exceeded 21.4 ml/min, AVF blood flow rose to more than 425 ml/min. The postoperative AVF blood flow in the group with RAF of more than 20 ml/min was significantly higher than that in those with less than 20 ml/min. Preoperative RAF of less than 20 ml/min had a significantly high risk of primary AVF failure within 8 months compared with that of more than 20 ml/min. It appears that measurement of RAF by ultrasonography is useful for estimating AVF blood flow postoperatively and can predict the risk of complications in ESKD patients.

The primary arteriovenous fistula failure—a comparison between diabetic and non-diabetic patients: glycemic control matters

Presence of diabetes mellitus has been shown to be related with the occurrence of primary arteriovenous fistula (AVF) failure in some but not in all studies. In the current study, we examined whether glycemic control as evaluated by HbA1c is independently related with primary AVF failure. We recorded sociodemographic, clinical, and laboratory parameters of the patients from medical records and hospital charts prior to AVF surgery. Primary AVF failure was described as a complication of the AVF before the first successful cannulation for HD treatment. Our study comprised of 160 non-diabetic (Group1) and 73 diabetic patients. Among diabetic patients, 37 had HbA1c values <7% (Group 2) and 36 patients had HbA1c values ≥7% (Group 3). In total, 74 (31.8%) patients had a history of primary AVF failure. The percentages of primary AVF failure were 27.5, 29.7, and 52.8% in Group 1, Group 2, and Group 3, respectively (P: 0.013). The percentage of patients with primary AVF failure was significantly lower in Group 1 and Group 2 than in Group 3 (P:0.003 and P:0.045, respectively). There was no difference with respect to primary AVF failure between Group 1 and Group 2 patients. We suggest that poor glycemic control as assessed by HbA1c may be an important factor for the development of primary AVF failure among diabetic subjects. It is possible that differences with respect to AVF failure between diabetic and non-diabetic patients may be partly attributed to glycemic control.

Primary arteriovenous fistula inflow proximalization for patients at high risk for dialysis access-associated ischemic steal syndrome

Establishing a functional vascular access while minimizing the risk of dialysis access-associated ischemic steal syndrome (DASS) may present a challenging problem in patients with severe peripheral vascular disease where even a low-flow arteriovenous fistula (AVF) may lead to severe symptoms and physical findings of DASS. Proximalization of arterial inflow for an existing vascular access is established as an effective treatment for DASS. We hypothesized that a primary proximal arterial inflow procedure for vascular access in patients judged to be at high risk for DASS would result in a successful hemodialysis access and mitigate the risk of steal syndrome. We report four such patients considered to be at significant risk for DASS after construction of a new vascular access. An axillary artery AVF inflow anastomosis was constructed in each patient. The access outflow configuration varied with the available venous outflow conduit identified during the preoperative ultrasound evaluation. In all four patients in this report, a functional autogenous dialysis access was established without DASS.

Mean Platelet Volume is not a Determinant of Primary Arteriovenous Fistula Failure in Hemodialysis Patients

Mean Platelet Volume is not a Determinant of Primary Arteriovenous Fistula Failure in Hemodialysis Patients

2D-Speckle Tracking Echocardiography Contributes to Early Identification of Impaired Left Ventricular Myocardial Function in Patients with Chronic Kidney Disease

Background/Aims: Our aim was to investigate left ventricular (LV) physiology and short-axis and long-axis regional LV myocardial function throughout the cardiac cycle with 2D-speckle tracking echocardiography (2D-STE) in patients with chronic kidney disease. Methods: The study population consisted of 40 maintenance hemodialysis patients (hemodialysis group), 20 uremic patients hospitalized for creation of primary arteriovenous fistula (nondialysis group), and a control group of 20 healthy volunteers. LV regional longitudinal, circumferential and radial peak systolic velocity (Vs); early diastolic velocity (Ve); and peak systolic strain (Ε) were measured with 2D-STE. Results: Increased LV wall thickness and a decreased E/A ratio were found in the nondialysis and hemodialysis groups as compared to the control group, but there was no difference between the 2 study groups. Longitudinal Vs and Ve of the LV basal segment and middle segment in hemodialysis group and nondialysis group were all slower than those in the control group, and Vs in the nondialysis group was slower than that of the hemodialysis group. Circumferential and radial Vs and Ve were not different among the 3 groups, except that the radial Vs of LV basal segment was markedly decreased in the nondialysis group. Longitudinal peak systolic strain in the hemodialysis and nondialysis groups were both decreased as compared to the control group. Circumferential and radial peak systolic strain was decreased only in the nondialysis group. Conclusions: 2D-STE may be used to identify early abnormalities in patients with chronic kidney disease who have preserved LV ejection fraction. LV regional function appeared to be better in the hemodialysis group than that in the nondialysis group.

Routine Preoperative Vascular Ultrasound Improves Patency and Use of Arteriovenous Fistulas for Hemodialysis

Arteriovenous fistulas (AVFs) are the preferred vascular access for hemodialysis but have a considerable failure rate. This study investigated whether routine preoperative vascular ultrasound results in better AVF outcome than physical examination. Patients with end-stage kidney disease referred for permanent access formation were assessed by independent examiners using physical examination and ultrasound. After random allocation, the ultrasound report was disclosed to the surgeon for patients in the ultrasound group but not for the clinical group. End points were AVF failure and survival rates, analyzed by intention to treat and by use for hemodialysis. AVFs were made in 208 of 218 randomized patients. Clinical and ultrasound groups were similar in terms of patient characteristics, allocation to individual surgeons, and proportion of forearm AVFs. The ultrasound group had a significantly lower rate of immediate failure (4% versus 11%, P = 0.028) and, among failed AVFs, less thrombosis (38% versus 67%, P = 0.029). Primary AVF survival at 1 year was not statistically different (ultrasound = 65%, clinical = 56%, P = 0.081). Assisted primary AVF survival at 1 year was significantly better for the ultrasound group (80% versus 65%, P = 0.012). The number of patients requiring preoperative ultrasound to prevent one AVF failure was 12. Routine preoperative vascular ultrasound in addition to clinical assessment improves AVF outcomes in terms of patency and use for dialysis. National Research Register, United Kingdom, trial number N0046131432.

Maintaining Vascular Access: The Management of Hemodialysis Arteriovenous Grafts

For the nephrologist and surgeon, maintaining vascular access is a significant challenge in hemodialysis (HD), because the portal is vulnerable to infection, stenosis, and thrombus. Vascular access options for HD include the placement of arteriovenous (AV) fistulas, AV grafts, and double-lumen, cuffed central vein catheters. Catheter use is generally associated with higher rates of infection and could compromise the adequacy of HD. Primary AV fistulas, which are generally recommended and provide excellent HD access, are not always the ideal choice for certain patients, such as the elderly or patients with diabetes mellitus. AV grafts allow for a large surface area available for cannulation, and thrombosed grafts have longer patency rates after revision than do revised fistulas. Although both AV fistulas and AV grafts are vulnerable to thrombosis and/or stenosis, surveillance and techniques such as Doppler ultrasound and intravascular ultrasound can minimize such complications. In addition, pharmacotherapeutic options are being studied to determine whether these complications can be prevented. Studies using a variety of pharmacologic agents have been conducted to determine whether stenosis and graft thrombosis can be prevented and have produced varying results. The use of warfarin can result in significant bleeding, but agents such as fish oil and angiotensin-converting enzyme inhibitors have shown some effect in increasing the patency in AV grafts and fistulas. Additional randomized trials with at least 1 or 2 yrs of follow-up are necessary to assess the long-term use of these pharmacotherapies.

Systemic arteriovenous fistulae for end-stage cyanosis after cavopulmonary connection: A useful bridge to transplantation

Intractable cyanosis after partial or complete cavopulmonary connection may rarely be managed by creating a systemic arteriovenous fistula. We investigated the long-term performance of arteriovenous fistulae. All 21 patients who received an arteriovenous fistula at The Hospital for Sick Children since the 1950s were investigated using parametric competing risk techniques. Primary arteriovenous fistula indication was (1) suboptimal pulmonary blood flow (N = 15) or (2) pulmonary shunting via pulmonary arteriovenous malformations (N = 6). Arteriovenous fistula longevity was determined by time to "occlusion" (absence of arteriovenous fistula flow via surgical ligation or spontaneous occlusion). All 21 patients had previously undergone second-stage palliation (Glenn shunt = 13; bidirectional shunt = 9). Five patients had undergone Fontan completion. Death in the presence of a functioning arteriovenous fistula occurred in 5 patients. Patients with bidirectional shunts had a significantly higher risk of death with a functioning arteriovenous fistula in situ (P = .04). High hemoglobin concentrations were associated with best outcome, and levels less than 170 g/L were associated with a high risk of death despite a functioning arteriovenous fistula (P < .01). Arteriovenous fistula occlusion occurred in 10 patients. Earlier occlusion was associated with previous Fontan completion (P = .02) and pulmonary arteriovenous malformations (P = .03). Surgical ligation during cardiac transplantation was the cause of occlusion in 7 patients. In these 7 patients, the arteriovenous fistula functioned for a median of 4.8 years. After transplantation, survival was 67% + or - 19% at 5 years. Overall survival was 73% + or - 10% 15 years after receiving an arteriovenous fistula (longest survival, 27.3 years). In patients with adequate hematocrit, arteriovenous fistula offers an effective bridge to transplantation when a high-risk Fontan procedure is deferred. Performance is best after unidirectional cavopulmonary connection and worse in the presence of pulmonary arteriovenous malformations. Survival is 75% at 15 years, despite being considered end stage.

Vascular Access in Patients Treated With Chronic Hemodialysis for 30 Years or More

The aim of our study was to evaluate vascular access in patients treated with chronic hemodialysis for 30 years or more. Patients who had started dialysis in 1978 or earlier were identified from the Slovenian Renal Replacement Therapy Registry. The data on vascular access on April 2008 are presented. Sixteen patients were still alive, seven men and nine women aged 62 +/- 12 years (46-84), and they had been treated for 32 +/- 1.7 years (30-35), mainly with chronic HD. They had started HD at the age of 30 +/- 12 years (13-50), and none had diabetes. The vascular access in nine was a native arteriovenous (AV) fistula, on the forearm in eight patients, and a brachiobasilic fistula in one patient. Four patients had their primary AV fistulas still in use (maximum 35 years). In the remaining five patients, multiple salvage procedures had been performed or new AV fistulas created. The vascular access in four patients was the polytetrafluoroethylene (PTFE) graft, functioning for 1-8 years. In three patients, a non-cuffed, single-lumen hemodialysis catheter (a precurved jugular in two patients and a subclavian in one) locked with 30% citrate, with mupirocin at the exit site, was used for 5-12 years. The catheters were exchanged approximately once every two years over a guide-wire because of mechanical damage. None of these three patients had had catheter-related sepsis or exit-site infection. Before catheters, these patients had had multiple AV fistulas and PTFE grafts. Although native AV fistula is the predominant type of vascular access, a greater than 30-year survival on hemodialysis is possible with the combined use of AV fistula, PTFE graft, and a non-cuffed hemodialysis catheter locked with citrate.

Preoperative Ultrasonographic Mapping of Blood Vessels Before Arteriovenous Fistula Construction in Elderly Patients With End‐stage Renal Disease

The aim of our retrospective study was to evaluate the ultrasonographic mapping of both arm and forearm vessels before primary arteriovenous fistula (AVF) construction in elderly patients with end-stage renal disease. There were 129 patients aged 75 +/- 6 (65-93) years, 58% men, 37% diabetics, who participated in the study. The inner diameter of veins (under compression) and arteries, and the arterial peak systolic velocity (PSV) were measured. The presence of arterial calcifications was noted. The positions for possible native AVF construction (radiocephalic and brachiocephalic) were suggested and an AVF was constructed by a trained nephrologist. An adequate cephalic vein was present in 76 (59%) patients (diameter 4.9 +/- 1.1 mm) in the right arm, and in 83 (64%) patients (4.7 +/- 1.2 mm) in the left arm. Suitable veins in the forearm were recorded in 73 (57%) patients on the right (3.7 +/- 0.7 mm) and in 76 (59%) patients on the left (3.5 +/- 1.0 mm) side. The inner arterial diameter was: brachial-right 4.6 +/- 0.6 mm (calcifications in 26%), left 4.6 +/- 0.7 mm (calcifications in 20%); radial-right 2.3 +/- 0.4 mm (calcifications in 36%), left 2.3 +/- 0.5 mm (calcifications in 29%). In 32% of patients, one native AVF was possible, in 17% two, in 23% three and in 18% four, while in 10% no AVF was possible. In 84% of patients an AVF was constructed, with no significant difference in non-diabetic vs. diabetic patients (88% vs. 80%) or females vs. males (87% vs. 83%). Native AVF can be constructed in the majority of elderly patients, often in multiple positions, with no significant differences in terms of sex or diabetic status.

Benefits of Intraoperative Digital Subtraction Angiography in Primary Arteriovenous Fistula Creation

Digital subtraction angiography (DSA) is an ideal procedure for improving vascular surgery results, not yet in use for arteriovenous fistula (AVF) creation. In a prospective study, the practicability and benefits of intraoperative completion DSA (CDSA) for this purpose were investigated. When the arteriovenous anastomosis was completed and clinically judged as running, DSA via percutaneous or open-site puncture was conducted. Findings and consequences were prospectively documented. From July 2005 to September 2006 a primary AVF was created in 54 patients. Fifty of these could be included in the study (68, 39-91 yrs). In 44 a forearm fistula, and in six patients an elbow fistula was newly created. In two cases we were unable to insert a cannula into the A. brachialis (study escape). In the remaining 48 cases, CDSA visualized afferent artery, anastomosis and draining vein. No complications occurred associated with CDSA; 3.5, 2-12 ml, contrast agent were required per patient. In 13 cases, CDSA revealed problems with the AVF that could be corrected immediately: the vein was freed from restraining soft tissue (n=4), a stealing venous branch was ligated (n=6), transluminal thrombectomy was conducted (n=1) or anastomosis was newly created (n=3). AVF could be successfully created proven by ongoing dialysis in 30 cases, and in eight cases as demonstrated by clinical and sonographic evaluations, resulting in a primary 1-yr patency rate of 79.2%. CDSA in AVF surgery is practicable and reveals conditions that can be corrected immediately, thus improving surgical outcome. Long since standard in other areas of vascular surgery, CDSA should become a routine procedure in AVF creation.

Preventing AVF thrombosis: the rationale and design of the Omega-3 fatty acids (Fish Oils) and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED) study

BackgroundHaemodialysis (HD) is critically dependent on the availability of adequate access to the systemic circulation, ideally via a native arteriovenous fistula (AVF). The Primary failure rate of an AVF ranges between 20–54%, due to thrombosis or failure of maturation. There remains limited evidence for the use of anti-platelet agents and uncertainty as to choice of agent(s) for the prevention of AVF thrombosis. We present the study protocol for a randomised, double-blind, placebo-controlled, clinical trial examining whether the use of the anti-platelet agents, aspirin and omega-3 fatty acids, either alone or in combination, will effectively reduce the risk of early thrombosis in de novo AVF.Methods/DesignThe study population is adult patients with stage IV or V chronic kidney disease (CKD) currently on HD or where HD is planned to start within 6 months in whom a planned upper or lower arm AVF is to be the primary HD access. Using a factorial-design trial, patients will be randomised to aspirin or matching placebo, and also to omega-3 fatty acids or matching placebo, resulting in four treatment groups (aspirin placebo/omega-3 fatty acid placebo, aspirin/omega-3 fatty acid placebo, aspirin placebo/omega-3 fatty acid, aspirin/omega-3 fatty acid). Randomisation will be achieved using a dynamic balancing method over the two stratification factors of study site and upper versus lower arm AVF. The medication will be commenced pre-operatively and continued for 3 months post surgery. The primary outcome is patency of the AVF at three months after randomisation. Secondary outcome measures will include functional patency at six and twelve months, primary patency time, secondary (assisted) patency time, and adverse events, particularly bleeding.DiscussionThis multicentre Australian and New Zealand study has been designed to determine whether the outcome of surgery to create de novo AVF can be improved by the use of aspirin and/or omega-3 fatty acids. Recently a placebo-controlled trial has shown that clopidogrel is effective in safely preventing primary AVF thrombosis, but ineffective at increasing functional patency. Our study presents significant differences in the anti-platelet agents used, the study design, and surgical and patient demographics that should contribute further evidence regarding the efficacy of anti-platelet agents.Trial RegistrationAustralia & New Zealand Clinical Trials Register (ACTRN12607000569404).

Randomized controlled trial of clopidogrel to prevent primary arteriovenous fistula failure in hemodialysis patients

The optimal vascular access for chronic maintenance hemodialysis is the arteriovenous fistula (AVF). Several studies suggest a role for antiplatelet agents in the prevention of primary AVF failure. A double-blind, randomized trial was conducted to assess the efficacy and safety of clopidogrel in hemodialysis patients. Ninety three patients were randomized to receive 75 mg/daily of clopidogrel or placebo. The treatment was initiated 7–10 days prior to scheduled access surgery and continued up to six weeks postoperatively, and then patients were monitored for six months. The primary outcome was AVF failure eight weeks after fistula creation. With a permuted block randomization schedule, 46 patients received clopidogrel and 47 patients received control placebo. The primary AVF failures at two months were 21.6% in placebo group and 5.2% in clopidogrel group (P = 0.03). The hazard ratio for the incidence of primary AVF failure was 0.72 (CI 95%, 0.41–1.01). Analysis of covariables indicated that this effect occurred principally as a result of clopidogrel administration. First hemodialysis from newly created AVF in clopidogrel group was significantly more successful than placebo group (P = 0.008). No life-threatening adverse event or severe bleeding was recorded in both groups. Clopidogrel seems to be effective and safe for prevention of primary AVF failure in hemodialysis patients.

Brachiobasilic versus brachiocephalic arteriovenous fistula: A prospective randomized study

The most recent Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines recommend that the order of preference for arteriovenous fistula (AVF) placement is the radial-cephalic primary AVF, followed by the secondary brachiocephalic (BC) and, if either of these is not viable, then brachiobasilic (BB) AVF should be fashioned. However, there is limited prospective data comparing technical and clinical outcomes of these two approaches. The purpose of our study was to compare outcome, patency, and complication rates in these two autogenous upper arm AV accesses. Between December 2003 and and January 2007, patients (61 male, 39 female) who have lost more distal AVFs were enrolled in the study. After preoperative duplex mapping, patients with patent both basilic and cephalic veins greater than 3 mm of diameter were randomized into BCAVF and BBAVF groups, each group consisting of 50 patients. All procedures were performed under local anesthesia as one-stage procedures. Follow-up data were prospectively collected. Kaplan-Meier analysis was used to calculate primary and secondary patency rates. Univariate and multivariate Cox-regression analysis was used to find risks for the occurrence of thrombosis. Baseline demographics, clinical characteristics, and preoperative history dialysis access were comparable between groups with the exception of the fact that mean caliber of the basilic veins were larger (4.51 +/- 0.93 mm vs 3.90 +/- 0.1 mm; P = .002). The mean duration of operation was significantly shorter in the BC group compared with the BB group (P < .001). There was no significant difference in the thirty day mortality, wound complications, 24 hour thrombosis, postoperative hemorrhage, maturation, and time to maturation between the groups. Mean follow-up was 43.2 +/- 1.8 months. Primary patency at 1 and 3 years of follow-up was 87% and 81% for the BC group and 86% and 73% for the BB group (P = .7) Secondary patency at one and three year follow-up was 87% and 70% for the BC group and 88% and 71% for the BB group, respectively (P = .8). Twenty-eight patients (28%) in the BC (18 patients) and BB (10 patients) group died with a patent fistula during the follow-up period (P = .18). Multivariate analysis revealed that use of dominant arm increased the risk of fistula failure. We conclude that brachiobasilic and brachiocephalic AVF are equally effective alternatives; however, a longer and demanding operation with BB AVF construction should be considered.

Primary and staged transposition arteriovenous fistulas

The use of catheters or prosthetic grafts for vascular access has significantly higher mortality and morbidity risks, in addition to higher costs, than arteriovenous fistulas (AVF). Many patients have a difficult access extremity due to complex medical illnesses, previous vascular access procedures, intravenous catheters, diabetes, vascular disease, female sex, age, and other complicating factors. Transposition AVFs (AVF-T) have been used for these individuals to avoid catheters and grafts. We report our experience with primary and staged basilic vein AVF-Ts and staged brachial vein AVF-Ts. From our database of consecutive vascular access operations, we reviewed patients from May 2003 to September 2006 for all upper extremity AVF-Ts. A primary AVF-T was used when the basilic vein was continuous with a minimum diameter of 4 mm and of adequate length. When the basilic vein was 2.5 to 4 mm, the procedure was staged. The proximal radial artery was used for inflow, if possible. When the basilic vein was not suitable, a radial vein or brachial vein anastomosis was performed as the first stage of a planned brachial vein AVF-T. The second stage operations of staged AVF-Ts were generally done 4 to 6 weeks after the primary AVF construction. All patients were evaluated with preoperative ultrasound imaging by the operating surgeon. From a database of 412 consecutive vascular access patients, 78 upper extremity transposition procedures were identified. Of these, 57 patients (73.1%) were women, 44 (56.4%) were diabetic, and 46 (59.0%) had previous access surgery. Fifty-eight operations were staged procedures. The basilic vein was used in 68 AVF-T, the brachial vein in six, and cephalic vein in four. The anastomosis was based on the proximal radial artery in 60 patients. Mean follow-up was 18 months (range, 3-48 months). Primary patency, primary assisted patency, and cumulative patency were 45.7%, 93.5%, and 96.0% at 12 months and 27.6%, 86.5%, and 88.9% at 24 months, respectively. No prosthetic grafts were used in the study period. Both primary and staged AVF-T procedures were successfully used in patients with difficult access extremities. AVF-Ts were durable, although many required an interventional procedure for maturation or maintenance. Cumulative (secondary) patency was 96.0% at 12 months and 88.9% at 24 months. The absence of an adequate basilic vein does not preclude the use of a staged AVF-T because the brachial vein offers a suitable alternative.

Stent Placement Versus Angioplasty Improves Patency of Arteriovenous Grafts and Blood Flow of Arteriovenous Fistulae

While endovascular stent placement is the standard of care in most percutaneous coronary and peripheral artery intervention, its role in the salvage of thrombosed and stenotic hemodialysis access remains controversial. We compared the effects of stent versus angioplasty on primary patency rates in the treatment of stenotic arteriovenous fistulae (AVF) and arteriovenous grafts (AVGs). Moreover, we compared access flow (Qa) and urea reduction ratio (URR) between the two groups as a metric of the effect of stent placement versus angioplasty on dialysis delivery. Cox regression analysis revealed that the primary assisted AVG patency was significantly longer for the stent group compared with angioplasty, with a median survival of 138 versus 61 d, respectively (aHR = 0.17; 95% confidence interval, 0.07 to 0.39; P < 0.001). The primary AVG patency for stent versus angioplasty was 91% versus 80% at 30 d, 69% versus 24% at 90 d, and 25% versus 3% at 180 d, respectively. The primary assisted AVF patency did not differ significantly between the stent and angioplasty groups. In patients dialyzing via AVF, multiple regression analysis revealed that stent placement was associated with improved after intervention peak Qa, 1627.50 ml/min versus 911.00 ml/min (beta = 0.494; P = 0.008), change in Qa from before to after intervention, 643.54 ml/min versus 195.35 ml/min (beta = 0.464; P = 0.012), and change in URR from before to after intervention, 5.85% versus 0.733% (beta = 0.389; P = 0.039). Our results suggest that stent placement is associated with improved AVG primary assisted patency and improved AVF blood flow, which may significantly impact on dialysis adequacy.

Hemodialysis Arteriovenous Fistula Patency Revisited

Vascular access standards are predominantly based on older, single-center reports; however, the hemodialysis population has changed dramatically and primary arteriovenous fistula failure is a huge problem. This prospective, multicenter study used standardized definitions to analyze patency rates and potential risk factors that affect functional patency and late arteriovenous fistula functionality. Eleven centers participated in a guidelines implementation program. All new permanent vascular accesses were included. Patency and functional patency, defined as access survival from creation and from first dialysis use, respectively, were calculated using Kaplan-Meier analysis. Risk factors for primary functional patency loss (intervention-free interval) and secondary failure (abandonment) were determined using regression models. A total of 491 arteriovenous fistulas were placed in 395 patients. Six-, 12-, and 18-mo secondary patency and functional patency were 75 +/- 2.0, 70 +/- 2.3, and 67 +/- 2.7% and 90 +/- 1.9, 88 +/- 2.2, and 86 +/- 2.7%, respectively. Primary failure rate was 40%. Thrombosis rate was 0.14 per patient-year. Diabetes and arteriovenous fistula surveillance were significantly associated with primary functional patency loss. Preoperative duplex was inversely related to secondary failure. The secondary failure rate per hospital varied from 0 to 39%. This study showed a marked difference between patency and functional patency, likely to be explained by high primary failure rates. Hemodialysis patients with diabetes can be expected to have reduced primary functional patency rates, but if treated adequately, then arteriovenous fistula functionality can be maintained as long as in patients without diabetes.