This systematic review and meta-analysis examine preventive operative techniques in high-risk patients undergoing surgery for hemodialysis access to mitigate the risk of Dialysis Access-Associated Steal Syndrome (DASS). Chronic kidney disease often leads to end-stage renal disease (ESRD), necessitating dialysis. Successful vascular access is crucial for efficient dialysis, but complications, such as DASS, pose significant challenges. DASS redirects arterial blood flow, affecting populations undergoing arteriovenous access surgery. This study aims to assess preventive strategies, including distal revascularization with interval ligation (DRIL) and extension techniques. A systematic search of PubMed, Cochrane Library, EMBASE, and Web of Science until 2022 identified 11 relevant studies. The inclusion criteria comprised non-pediatric hemodialysis patients reporting outcomes related to patency and complications. The data were analyzed using Review Manager 5.3.5 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen). Meta-analysis indicated a significant association between DASS and arteriovenous fistula (AVF) or arteriovenous graft (AVG) procedures. Radiocephalic AVF (RC-AVF) and distal endovascular AVF procedures were favored. Various interventions addressed venous narrowing, including simple plication and loop interposition. The Modified by Inserted Latex Link for Endovascular Repair (MILLER) technique, DRIL, Extension Technique, and Proximalization of Arterial Inflow (PAI) were assessed for arterial bypass graft and blood supply preservation. This study underscores the importance of individualized strategies in preventing DASS during hemodialysis access surgery. Prophylactic measures, such as the extension technique, show promise, while DRIL remains effective in treatment. Ongoing research is imperative for optimizing outcomes in this complex patient population.

Although randomised controlled trials (RCT) are considered the optimal form of evidence, there are relatively few in surgery. Surgical RCT are particularly likely to be discontinued with poor recruitment cited as a leading reason. Surgical RCT present challenges over and above those seen in drug trials as the treatment under study may vary between procedures, between surgeons in one unit, and between units in multi-centred RCT. The most contentious and debated area of vascular access remains the role of arteriovenous grafts, and thus the quality of the data that is used to support opinions, guidelines and recommendations is critical. The aim of this review was to determine the extent of variation in the planning and recruitment in all RCT involving AVG. The findings of this are stark: there have been only 31 RCT performed in 31 years, the vast majority of which exhibited major limitations severe enough to undermine the results. This underlines the need for better quality RCT and data, and further inform the design of future studies. Perhaps most fundamental is the planning for a RCT that accounts for the intended population, the uptake of a RCT and the attrition for the significant co-morbidity in this population.

Arteriovenous fistula (AVF) is currently the hemodialysis access with the longest life expectations for the patients. However, even the AVF is at risk for many complications, especially the development of stenosis. The latter can not only lead to inadequate hemodialysis but also lead to AVF thrombosis. Duplex Doppler ultrasonography is a very precise method, in the hands of experienced professionals, for the diagnosis of AVF complications. In this review, we summarize the ultrasound diagnostic criteria of significant stenoses and their indication for procedural therapy.

It is challenging for a surgeon to determine the appropriate vascular access for hemodialysis patients whose cephalic vein is usually inaccessible. The purpose of the study is to compare the complications and patency rates between transposed arteriovenous fistulas (tAVF) and arteriovenous graft (AVG) for the hemodialysis patients. Studies were recruited from PubMed, Cochrane library, EMBASE, the web of science databases, and reviewing reference lists of related studies from the inception dates to September 2, 2021. Statistical analyses were conducted using the statistical tool Review Manager version5.3 (Cochrane Collaboration, London, UK). I2 > 50% was defined as a high degree of heterogeneity, and then a random-effects model was used. Otherwise, the fixed-effects model was used. Odds ratio with its 95% confidence interval (95% CI) was used. Thirty-three trials (26 retrospective studies, four randomized controlled trials, two prospective trials, and one controlled-comparative study) with 6430 enrolled participants were identified in our analysis. The results showed that tAVF was accompanied with lower thrombosis rate (103/1184 (8.69%) vs 257/1367 (18.80%); I2 = 45%; 95% CI, 0.34 (0.26, 0.45)) and infection rate (43/2031 (2.12%) vs 180/2147 (8.38%); I2 = 0%; 95% CI, 0.20 (0.14, 0.30)) than arteriovenous graft. The significantly better primary patency rates, secondary patency rates, and primary assisted patency rates during follow-up were found in tAVF. However, the failure rate and the prevalence of hematoma were significantly lower in AVG group. No evidence showed the rate of overall mortality, steal syndrome, and aneurysm reduced in tAVF. Our results showed that tAVF is a promising vascular access technique for hemodialysis patients whose cephalic vein is inaccessible. Our data showed that tAVF has less thrombosis, infection risk, and better patency rates when compared with AVG. However, more attentions need to be paid to transposed arteriovenous fistulas maturation and hematoma.

The number of elderly patients initiating hemodialysis (HD) increased considerably over the past decade. Arteriovenous fistulas (AVFs) are the preferred vascular access (VA) type in most HD patients. Choice of VA for older hemodialysis patients presents a challenge. The higher incidence of comorbidities, longer AVF maturation times, risk of primary failure, risk of patency loss, and shorter life expectancy are important factors to consider. In this review we provide a comprehensive analysis on maturation rates, primary failure, patency, and mortality regarding vascular access in patients older than 75 years of age.

Arteriovenous grafts (AVGs) are an appropriate option for vascular access in certain hemodialysis patients. Expanded polytetrafluoroethylene (ePTFE) has become the dominant material for such grafts, due in part to innovations in graft design and surgical interventions to reduce complications and improve patency rates. Comprehensive evidence syntheses have not been conducted to update AVG performance in an era in which both access choice and ePTFE graft functioning may have changed. We conducted a systematic review and meta-analysis summarizing outcomes from recent studies of ePTFE AVGs in hemodialysis, following PRISMA standards. Literature searches were conducted in multiple databases to identify observational and interventional studies of AVG patency and infection risk. Primary, primary-assisted, and secondary patency rates were analyzed at 6, 12, 18, and 24 months postplacement. Kaplan-Meier graft survival plots were digitized to recreate individual patient-level data. Patency rates were pooled using a random effects model. We identified 32 studies meeting our selection criteria that were published from 2004 through 2019. A total of 38 study arms of ePTFE grafts were included, representing 3381 AVG accesses placed. The mean primary, primary-assisted, and secondary patency rates at 1 year were 41% (95% CI, 35% to 47%), 46% (95% CI, 41% to 51%), and 70% (95% CI, 64% to 75%), respectively. Mean 24-month patency rates were 28% (95% CI, 22% to 33%), 34% (95% CI, 27% to 41%), and 54% (95% CI, 47% to 61%), respectively. A high degree of heterogeneity across studies was observed. Overall risk of infection was not consistently reported, but among available studies the pooled estimate was 9% per patient-year (95% CI, 6% to 12%). This meta-analysis provides an up-to-date estimate of the performance of ePTFE AVGs, within the context of improved graft designs and improved interventional techniques.

BACKGROUND: Controversy exists regarding the best-performing vascular access type for patients undergoing haemodialysis. We aimed to compare outcomes of starting dialysis on arteriovenous fistulas (AVFs) versus arteriovenous grafts (AVGs) in haemodialysis patients.
METHODS: We conducted a systematic search of multiple electronic information sources and bibliographic reference lists. The following outcome parameters were evaluated at 1, 2 and 5 years: primary failure, defined as access never used for dialysis; primary patency, defined as intervention-free access survival; primary-assisted patency, defined as uninterrupted access survival with interventions; and secondary patency, defined as cumulative access survival.
RESULTS: We identified 15 comparative studies reporting a total of 118,434 patients who initiated haemodialysis with AVF (n = 95,143) or AVG (n = 23,291). Our analysis demonstrated that AVF was associated with significantly higher primary failure rate (OR: 2.05, p = .0005) but significantly higher rate of primary patency at 1 year (OR: 1.91, p < .00001), at 2 years (OR: 2.52, p < .00001) and at 5 years (OR: 2.59, p < .00001); and primary-assisted patency at 1 year (OR: 1.71, p < .00001), at 2 years (OR: 2.13, p < .00001) and 5 years (OR: 2.79, p < .00001). There was no significant difference in secondary patency at 1 year (OR: 1.08, p < .00001) but AVF had better secondary patency at 2 years (OR: 1.26, p < .00001) and 5 years (OR: 1.60, p < .00001) than AVG.
CONCLUSIONS: The meta-analysis of best available comparative evidence (Level 2) demonstrated that AVFs may be associated with significantly higher primary failure rate but higher primary patency, primary-assisted patency and secondary patency at 1, 2 and 5 years compared to AVGs. However, the available evidence is subject to significant selection bias and confounding by indication.

UNASSIGNED: It is unclear whether tapered arteriovenous grafts (AVGs) are superior to non-tapered AVGs when it comes to preventing upper extremity ischemic steal syndrome. We aimed to evaluate the outcomes of tapered and non-tapered AVGs using systematic review and meta-analysis.
UNASSIGNED: A literature search was systemically performed to identify all English publications from 1999 to 2019 that directly compared the outcomes of upper extremity tapered and non-tapered AVGs. Outcomes evaluated were the primary patency at 1-year (number of studies (n) = 4), secondary patency at 1-year (n = 3), and risk of ischemic steal (n = 5) and infection (n = 4). Effect sizes of individual studies were pooled using random-effects model, and between-study variability was assessed using the I2 statistic.
UNASSIGNED: Of 5808 studies screened, five studies involving 4397 patients have met the inclusion criteria and included in the analysis. Meta-analyses revealed no significant difference for the risk of ischemic steal syndrome (pooled odds ratio (OR) 0.92, 95% Confidence Incidence (CI) 0.29-2.91, p = 0.89, I2 = 48%) between the tapered and non-tapered upper extremity AVG. The primary patency (OR 1.33, 95% CI 0.93-1.90, p = 0.12, I2 = 10%) and secondary patency at 1-year (OR 1.49, 95% CI 0.84-2.63, p = 0.17, I2 = 13%), and rate of infection (OR 0.62, 95% CI 0.30-1.27, p = 0.19, I2 = 29%) were also similar between the tapered and non-tapered AVG.
UNASSIGNED: The risk of ischemic steal syndrome and patency rate are comparable for upper extremity tapered and non-tapered AVGs. This meta-analysis does not support the routine use of tapered graft over non-tapered graft to prevent ischemic steal syndrome in upper extremity dialysis access. However, due to small number of studies and sample sizes as well as limited stratification of outcomes based on risk factors, future studies should take such limitations into account while designing more robust protocols to elucidate this issue.

OBJECTIVE: Arteriovenous grafts (AVGs) are the second best option for haemodialysis access when native arteriovenous fistulae placement is not possible, because they have a lower patency owing to neointimal hyperplasia at the venous anastomosis. This review aimed to evaluate the effect of geometric graft modification to the graft-vein interface on AVG patency.
METHODS: The MEDLINE and Embase (OvidSP) databases were systematically searched for relevant studies analysing the effect of geometrically modified AVGs on graft patency and stenosis formation (last search July 2019).
METHODS: Data regarding AVG type, patency, and graft outlet stenosis was extracted for further evaluation. Data were pooled in a random effects model to estimate the relative risk of graft occlusion within one year. Follow up, number of patients, and relevant patient characteristics were extracted for the quality assessment of the included studies using Newcastle-Ottawa Scale and Cochrane Risk of Bias Tool. The quality of the evidence was determined according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system.
RESULTS: Search strategies produced 2772 hits, of which eight articles met predetermined inclusion criteria. Overall, the included articles had low to moderate risk of bias. In total, 414 expanded polytetrafluoroethylene AVGs (232 geometrically modified and 182 standard) were analysed, comprising two modified AVG types: a prosthetic cuff design (Venaflo®) and grafts with a Tyrell vein patch. Overall, modified grafts did not show a statistically significantly higher one year primary (relative risk [RR] 0.86, 95% confidence interval [CI] 95% 0.64-1.16; GRADE: \"low to very low\") or secondary patency (RR 0.57, 95% CI 0.32-1.02; GRADE: \"low to very low\") when compared with standard AVGs. Analysis of prosthetic cuffed grafts (112 patients) separately demonstrated a statistically significantly higher one year primary (RR 0.75, 95% CI 0.61-0.91) and one year secondary patency (RR 0.47, 95% CI 0.30-0.75) compared with standard grafts (92 patients). The results on stenosis formation were inconclusive and inadmissible to quantitative analyses.
CONCLUSIONS: The meta-analysis showed that a prosthetic cuff design significantly improves AVG patency, while a venous cuff does not. Although the heterogeneity and low number of available studies limit the strength of the results, this review shows the potential of grafts with geometric modification to the graft-vein anastomosis and should stimulate further clinical and fundamental research on improving graft geometry to improve graft patency.

OBJECTIVE: There is currently uncertainty regarding the ideal treatment to salvage thrombosed or failing synthetic arteriovenous grafts (AVGs) in patients with end stage renal disease. Therefore, a systematic review up to December 2018 and network meta-analysis of randomised control trials (RCTs) that compared three month failure risk of available treatments was carried out.
METHODS: Medline, Scopus, Embase, and the Cochrane Library were the data sources. Pairwise meta-analyses were based on random effects models. Network meta-analysis was conducted within a frequentist framework with a multivariable random effects approach to model treatment effects across studies. The metric of choice was the odds ratio (OR) along with the associated 95% confidence interval (CI).
RESULTS: Sixteen two arm RCTs were included involving 2011 patients who were randomised to six different treatments (plain balloon angioplasty, open surgical repair, stents, stent grafts, drug eluting balloons (DEBs), and cutting balloons). The network of RCTs had a star like geometry with plain balloon angioplasty being the common comparator. There were no significant differences between treatments with regards to risk of failure at three months with the exception of stent graft use that significantly reduced the risk of failure compared with plain balloon angioplasty (OR 0.53, 95% CI 0.34-0.84). Based on surface under the cumulative ranking curve (SUCRA) values, the best interventions to salvage thrombosed or failing AVGs were DEB and stent grafts.
CONCLUSIONS: Stent graft seems to perform better than plain balloon angioplasty in terms of saving thrombosed or failing AVGs. However, this network meta-analysis was limited by the lack of closed loops and thus unable to assess consistency between direct and indirect evidence. The efficacy of DEBs as a promising treatment deserves further investigation and new RCTs are required.