Comparison of efficacy of side to side versus end to side arteriovenous fistulae formation in chronic renal failure as a permanent hemodialysis access

A review of technical steps in the performance of arteriovenous fistula creation

Although it is accepted that a functional arteriovenous fistula (AVF) is the optimal vascular access for dialysis, achieving function is difficult as the outcomes of AVF creation are sub-optimal. Many technical steps have been proposed to improve outcomes, but the strength of evidence to support these is unclear. Thus, a systematic review of all randomised controlled trials (RCT) of operative strategies to optimise AVF outcomes was performed to summarise the evidence, review the overall level of standardisation in RCT and thus determine if there was an objective basis for the technical steps in AVF creation. A systematic review of all RCT was performed and studies categorised by intervention type. The rationale for each intervention, outcomes and limitations were described. Most importantly, the completeness of reporting procedural steps was compared for all RCT and the therapeutic impact considered by AVF site. Of 6741 records meeting the search criteria, 31 RCT were included. Most RCT did not control for all technical aspects or fully detail the operative methods, with a mean of 4 technical steps not reported for which other RCT have been performed. Of studies involving a surgical intervention in RCF, 10/13 reported a significant benefit compared to only 5/15 studies in BCF or larger vessels. Overall, the adequacy of reporting the technical details in all RCT of technical steps in AVF creation was poor. Despite this, there was a consistent patency benefit found in RCT performed in smaller vessels although the extent of interaction between these is uncertain. There remain gaps in the literature in defining the optimal steps in fistula creation that, if confirmed, could significantly improve AVF outcomes. This makes it essential that future studies of novel techniques, such as percutaneous AVF creation, incorporate a standardised operating procedure of optimal current practice of surgically created AVF as a meaningful comparator.

Comparison of End-To-Side and Side-To-Side Anastomosis Techniques in Arteriovenous Fistula for Hemodialysis: A Systematic Review and Meta-Analysis

Autogenous arteriovenous fistula (AVF) is the vascular access of choice for chronic kidney disease to patients requiring hemodialysis. However, there still needs to be more consensus on whether the best surgical approach is an end-to-side (ETS) or a side-to-side (STS) anastomosis. This study aims to compare venous maturation rates, midterm patency and postoperative steal syndrome rates between ETS and STS techniques for AVFs. Three databases were searched during November 2022: PubMed, Scopus, and ISI Web of Knowledge. Two independent reviewers examined both titles and abstracts. In all studies, eligibility was assessed, and data regarding the study's characteristics, methods, and considered outcomes were obtained. The odds ratio (OR) assessed maturation rates, 6- and 12-month patency, and steal syndrome. Meta-analysis was done using a fixed effects model if I2 values were under 30%, and a random-effects model from 30-60%. Thirteen studies were included, with a total of 1960 patients studied. Patients undergoing ETS anastomosis had higher maturation rates (OR 3.30 95% confidence interval [CI] 1.81, 6.00, I2 = 20%). No difference was found in patency at 6 months (OR 1.05 95% CI 0.69, 1.59, I2 = 54%) and 12 months (OR 0.75 95% CI 0.46, 1.23, I2 = 7%). Regarding steal syndrome, STS anastomosis presented a greater risk of developing this postoperative complication (OR 0.24 95% CI 0.11, 0.50, I2 = 0%). The present review suggests that ETS anastomosis is associated with higher maturation rates and a lower risk of arterial steal syndrome. Randomized clinical trials are required to confirm our findings.

International survey of radiocephalic arteriovenous fistula: ISRAF survey

AIMS

The objective of this survey was to encompass the full scope of international practice, entailing all technical, non-technical, preoperative stratification and functional maturation (FM) of RCAVF.

METHODS

The survey contained n = 19 questionnaires with n = 46 variables completed by n = 85 providers from n = 21 nations across n = 5 continents. The numerical values were subjected to mean with standard error whereas the nominal data to a non-parametric (Kruskal-Wallis & Spearman correlation test) and analysis of variance (ANOVA). The test of homogeneity, & probability was reported 95% confidence intervals (CI) alongside error plots. Furthermore, a decision and higher attribute tree model was constructed based on current survey for higher FM in RCAVF.

RESULTS

FM is independently associated with volume of surgeon per year (procedures performed) (p < 0.01) [High Volume: 73% (95% CI, 68-77%) versus Average volume: 63% (95% CI, 59-66%) vs Low volume: 56% (95% CI, 51-61%)]. FM increased by 8% with every 20 more procedures per group of surgeons on end point of FM. Amongst continents: Australia, America, Asia and South America demonstrated higher FM to Africa & Europe (p < 0.05). UK possessed a lower FM 58% (95% CI, 48-68%) in comparison to the world & Europe respectively [65% (95% CI, 61-70%) vs 61% (95% CI, 58--65%)]. There was a positive causal link between angle of anastomosis at 30-76° (p < 0.01), longitudinal & S-shaped incision & arteriotomy length of 3 & 4 mm to higher FM (p < 0.05).

CONCLUSION

FM in RCAVF is independently & incrementally associated with the volume of surgeon per year. There is a diverse inclusion, exclusion and technical approach in RCAVF creation. This survey advocates the importance of international collaboration and/or registry in assimilation, consolidate and development of consensus.

The Pathological Mechanisms and Therapeutic Molecular Targets in Arteriovenous Fistula Dysfunction

The number of patients with end-stage renal disease (ESRD) requiring hemodialysis is increasing worldwide. Although arteriovenous fistula (AVF) is the best and most important vascular access (VA) for hemodialysis, its primary maturation failure rate is as high as 60%, which seriously endangers the prognosis of hemodialysis patients. After AVF establishment, the venous outflow tract undergoes hemodynamic changes, which are translated into intracellular signaling pathway cascades, resulting in an outward and inward remodeling of the vessel wall. Outward remodeling refers to the thickening of the vessel wall and the dilation of the lumen to accommodate the high blood flow in the AVF, while inward remodeling is mainly characterized by intimal hyperplasia. More and more studies have shown that the two types of remodeling are closely related in the occurrence and development of, and jointly determining the final fate of, AVF. Therefore, it is essential to investigate the underlying mechanisms involved in outward and inward remodeling for identifying the key targets in alleviating AVF dysfunction. In this review, we summarize the current clinical diagnosis, monitoring, and treatment techniques for AVF dysfunction and discuss the possible pathological mechanisms related to improper outward and inward remodeling in AVF dysfunction, as well as summarize the similarities and differences between the two remodeling types in molecular mechanisms. Finally, the representative therapeutic targets of potential clinical values are summarized.

Percutaneous arteriovenous fistula creation in the management of severe Hemophilia A and end-stage kidney disease needing hemodialysis access, and beyond

With the contemporary KDOQI, a patient-focused approach in vascular access care is emphasized more than ever when planning RRT. Nevertheless, functional vascular access continues to be the Achilles' heel for successful hemodialysis in specific patient sub-groups, such as the Hemophilia-A population. The newer percutaneous endovascular approach is a safer alternative when conventional surgical AVF poses high bleeding risks perioperatively, which subsequently prevents ESKD patients to have desired permanent dialysis access. This article presents the case of a 45-year-old male with severe Hemophilia-A, who has been dialysis-dependent due to diabetic kidney disease and hypertension. Due to the severity of his progressively worsening bleeding disorder, his previous surgeries to treat other comorbidities have been complicated and involved challenging peri-operative treatment courses that include blood and factor VIII infusions, bleeding wounds, along with prolonged hospital stays. With the fear of bleeding diathesis, a conventional surgical AVF was not pursued, which has left him with a prolonged tunneled CVC while not being considered a candidate for peritoneal dialysis. We offered the patient a left arm percutaneous endovascular AVF creation with the WavelinQ™ 4F Endo-AVF system as an alternative option for his permanent hemodialysis access. An Endo-AVF was created bloodlessly between the left radial artery and lateral radial vein percutaneously with only two 4-French accesses at left wrist. The patient has been receiving full sessions of hemodialysis with expected flow rates and free of the CVC since. Likely the first case of such utilization reported, the utilization of percutaneous Endo-AVF for this patient has suggested not only that the endovascularly created AVF offers a good alternative dialysis access for hemophilia A patient populations, but also due to this technology's unique features, it can be potentially employed in other situations, such as needs for reliable and chronic venous accesses and blood product exchanges.

Comparison of end-to-side versus side-to-side anastomosis in upper limb arteriovenous fistula in hemodialysis patients: A systematic review and meta-analysis

Objective

It is currently unclear if the anastomosis technique impacts the patency of upper arm arteriovenous fistula (AVF) in hemodialysis patients. This review compared outcomes of end-to-side and side-to-side anastomosis for AVF fistula in hemodialysis patients.

Methods

PubMed, CENTRAL, Web of Science, and Embase were searched for all types of studies published between 1st January 2000 to 3rd September 2022. Patency rates at 6, 12 months, maturation time, and complications were compared between ETS and STS groups.

Results

Sixteen studies including six randomized controlled trials (RCTs) were included. Meta-analysis showed no difference in patency rates between ETS and STS group at 6 months (OR: 1.15 95% CI: 0.72, 1.83 I ² = 52% p = 0.56) but better patency with STS at 12 months (OR: 0.63 95% CI: 0.41, 0.95 I ² = 21% p = 0.03). The difference was non-significant in a subgroup analysis of RCTs and non-RCTs. In the absence of distal vein ligation in the STS group, the ETS group had significantly better patency at 6 months but with distal vein ligation, STS had higher patency at 12 months. Meta-analysis demonstrated no difference in maturation time between the two groups (MD: 0.10 95% CI: 0.29, 0.49 I ² = 89% p = 0.61). Only a descriptive analysis of complications could be carried out with no major difference.

Conclusion

Our review demonstrates that the STS anastomosis technique with distal vein ligation may result in significantly better patency rates as compared to the standard ETS technique. Data for complication rates are scarce and varied but without any significant differences between the two techniques.

End-to-side versus side-to-side anastomosis with distal vein ligation for arteriovenous fistula creation

INTRODUCTION

There is lack of compelling evidence about the best technique to carry out the anastomosis between the artery and the vein: end to side or side to side. This issue was addressed by very few randomized controlled studies. This topic has recently re-emerged with the advent of the endovascular fistula creation using the side-to-side technique.Objectives: To compare the results of both surgical techniques for the creation of arteriovenous anastomosis.

METHODS

This is a randomized controlled prospective study. All renal failure patients, 18 years and older, referred to our institution requiring creation of a new arm arteriovenous fistulas, including distal radio-cephalic, ulno-basilic, proximal brachio-cephalic or brachio-basilic configurations were included.

RESULTS

Between February 2018 and October 2018, 378 patients underwent creation of permanent haemodialysis access. A total of 100 patients were randomized equally into the end-to-side and side-to-side groups. Follow-up for the study purpose continued until May 2019 (mean = 9 months, range 1-12). Patients' age ranged from 19 to 68 years. Sevety-seven arteriovenous fistulas were created at the elbow (37 brachio-basilic and 40 brachio-cephalic). Radio-cephalic fistulae were 23, created at wrist and in the forearm. Primary technical success was 97%, and 35 (70%) and 17 (34%) cases achieved functionally maturation in the end-to-side and side-to-side groups, respectively (P = 0.0001). Primary and secondary patency rates at 12 months were 76% end to side versus 78% STS (P = 0.381) and 84% end to side versus 86% STS (P = 0.225), respectively.

CONCLUSION

End-to-side technique should be used in all instances of arteriovenous fistulas creation.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Comparison of side-to-end vs. side-to-side proximal arteriovenous fistula anastomosis in chronic renal failure patients

Introduction

Anastomotic creation of autogenous arteriovenous fistulas can be performed in different ways, side-to-end or side-to-side. However, there is a paucity of evidence to recommend them. The aim of this study is to compare both anastomosis types in elbow arteriovenous fistulas.

Material and methods

A prospective observational national multicenter study (ISRCTN62033470) was designed, including patients receiving a native arteriovenous fistula in the elbow using side-to-end or side-to-side anastomosis, between September, 2016 and September, 2017, with six-month postoperative follow-up period. Patient characteristics, surgical details, and follow-up data (primary, assisted primary and secondary patency, maturation, functionality, complications) were recorded and compared between both anastomosis groups using Kaplan–Meier curves estimations, at one and six-month follow-up, and finally a multivariate analysis with Cox regression was performed.

Results

Three centers participated in the study, including 133 cases (96 side-to-end, 37 side-to-side). The cephalic vein was more often used for side-to-end (58.3%) and basilic for side-to-side (78.4%; P < 0.001). Side-to-end anastomoses were faster to create (65.1–75.1 min; P = 0.009). During follow-up, 23 cases were lost (transplanted, dead, ligated, or lost), with no differences at one month. At six months, primary patency was better for the side-to-end group (78.5 − 55.9%; P = 0.038), but it was not confirmed as an independent predictor in the multivariate analysis. Furthermore, no significant differences in assisted primary or secondary patency, maturation or functionality were seen. Patients with side-to-side anastomosis more often required vein superficialization (2.1–16.2%; P = 0.002) and presented more frequent puncture hematomas (4.9–30.0%; P = 0.015).

Conclusions

Anastomosis type was not significantly related to different outcomes in the follow-up. Even though side-to-end anastomosis showed better primary patency at six months with lower need of vein superficialization and fewer puncture hematomas during follow-up, it was not confirmed as an independent predictor in the multivariate analysis, and similar assisted primary and secondary patency, maturation, and functionality rates have been seen after arteriovenous fistula creation.

Independent association of arteriovenous ratio index on the primary functional maturation of autologous radiocephalic arteriovenous fistula

OBJECTIVE

It has been hypothesized that a novel measurement technique of arteriovenous ratio (AVR) index obtained from inflow (radial artery diameter) to that of outflow (cephalic vein diameter) and its application through the Bernoulli effect has no impact on the primary functional maturation (FM) of autogenous radiocephalic arteriovenous fistula (RCAVF).

METHODS

A prospective consecutive single-center cohort study with intention to treat of 324 patients undergoing RCAVF during a period of 4 years was conducted. Variables of demographics, anatomic factors, laterality, comorbidities, anesthesia type, presence of intraoperative thrill, angle of anastomosis, and AVR index were assessed through univariate and multivariate logistic regression analysis on the end point of FM. The AVR was subjected to three decimal points to ensure maximal accuracy for best sensitivity and 1 - specificity by receiver operating characteristic curve. The χ² (subgroup) analyses were undertaken to investigate the differences in FM incidence within different ranges of AVR. Test of probability (P value) was considered to be significant with P < .05. Effect sizes were reported as odds ratio with their measure of uncertainty at 95% confidence intervals.

RESULTS

Among all variables, the AVR index remained the only independent factor associated with FM (66%; n = 214/324) of RCAVFs (P = .001; 95% confidence interval, 0.08-0.26). AVR of 1 to 1.06 was associated with 100% FM in RCAVFs. Decrease or increase of this index was associated with stepwise reduction in FM of RCAVFs (P < .05).

CONCLUSIONS

The suggested novel measurement technique (AVR index) is an independent predictor of FM in RCAVFs. This study implies that minimal diameter (ie, inflow artery dimeter to outflow cephalic vein diameter) mismatch (AVR, 1-1.06) irrespective of other variables remains crucial for optimal hemodynamics (pressure and velocity) of RACVFs and their primary FM.

End-To-Side versus Side-To-Side Anastomosis in Upper Limb Arteriovenous Fistula for Dialysis Access: A Systematic Review and a Meta-Analysis

BACKGROUND

An arteriovenous fistula (AVF) is the best modality for hemodialysis access. The end-to-side (ETS) technique has been suggested in the literature to produce superior results to the side-to-side (STS) approach; however, in the absence of a systematic review, this practice remains debatable.

METHODS

Online search for randomized controlled trials and observational studies that compared the ETS versus the STS anastomosis techniques in creating an upper limb AVF. Aims were to systematically assess the difference between both procedures in terms of access maturation, patency, and postoperative complications.

RESULTS

Seven studies were included with 463 patients in the ETS group and 523 in the STS group. The difference between the 2 techniques was not significant in relation to patency rates at 3, 6, 12, and 24 months (P values: 0.28, 0.82, 0.54, and 0.21, respectively). There were fewer cases of postoperative hematoma in the ETS group; however, the difference was not significant (P = 0.09). Arterial steal syndrome was found to be significantly associated with the STS configuration in pooled analysis (pooled risk ratio = 0.11 [0.01-0.88], 95% CI, P = 0.04).

CONCLUSIONS

Similar maturation rates between ETS and STS fistula configuration, however, arterial steal syndrome was significantly associated with the STS technique. ETS will likely remain as the preferred AVF configuration as it is less technically demanding.

Reporting Quality Assessment of Randomized Controlled Trials Published in Nephrology Urology Monthly Journal

CONTEXT

Randomized controlled trials (RCTs) are important tools for evidence-based health care decisions. It is, therefore, important that they be conducted and reported with the highest possible standards. The aim of this study was to evaluate the reporting quality of the RCTs published in nephrology urology monthly journal and to examine whether there was a change over time in the reporting quality.

EVIDENCE ACQUISITION

The quality of each report was assessed using the Consolidated Standards of Reporting Trials (CONSORT) 2010 Statement checklist and a 5-point quality assessment instrument, i.e. the Jadad scale.

RESULTS

Eighteen (14 Iranian and 4 non-Iranian) RCTs were published from 2012 to 2014 on topics including renal stone (16.6%), hemodialysis and transplantation (38.8%), and prostate conditions (11.1%). Interventions comprised surgery, drugs, and teaching method in 7 (38 %), 10 (55%), and 1 (5%) of them, respectively. According to the CONSORT checklist, the weakest reported items were registration number, identification as a randomized trial in the title, and settings and locations where the data were collected. The mean Jadad score of the reports was 2.72 ± 1.36 (54% of their maximum possible total score). According to the Jadad and CONSORT scales, there was an increase in the quality of reporting from 2012 to 2014.

CONCLUSIONS

This assessment shows low reporting quality scores in reports. Training courses for researchers, using standard reporting tools (e.g. CONSORT 2010 Statement checklist), and consultation with methodologists can improve the quality of published RCTs.

Elbow Arteriovenous Fistulae

Multiple superficial veins in different anatomical configurations exist in the elbow. The resulting variety of elbow arteriovenous fistulae (AVFs) is described in this paper. A classification of elbow AVF in nontransposed AVF, transposed AVF and multiple outflow AVF is proposed. The nontransposed brachiocephalic AVF has the lowest primary failure rate and a good medium-term survival particularly in the elderly. The simplest technique is an end-to-side anastomosis of the median cubital vein to the brachial artery. In cases of small upper arm veins, a perforating vein AVF, using multiple outflow tracts, may be helpful to lower primary failure risk. In the era of vein mapping with portable ultrasound elbow AVF should be made when forearm veins are exhausted or too small. A side-to-side AVF in order to enhance retrograde flow in the median forearm vein seems rarely indicated, in particular considering the greater risk of steal and venous hypertension. A transposed brachiobasilic AVF is a tertiary access procedure after the simpler alternatives have been exhausted. There is conflicting evidence of the benefits of one-stage versus two-stage procedures. Therefore, the type of operation should be tailored to the individual patient.