Standardized definitions for hemodialysis vascular access

Is Endovascular Arteriovenous Fistula a Feasible Alternative for Hemodialysis Patients?

INTRODUCTION

For hemodialysis (HD) patients, the selection of vascular access is a crucial factor that significantly affects morbidity and mortality. Historically, native arteriovenous fistulas (AVFs) have been established using surgical techniques. However, devices facilitating percutaneous endovascular arteriovenous fistula (endoAVF) formation have recently been introduced in clinical practice, showing promising initial evidence. The primary objectives were technical success, efficacy, and cannulation rates. The secondary objectives included primary and cumulative patency, safety, and the number of procedures required to maintain fistula patency.

METHODS

A prospective, single-center, single-arm study included all patients who underwent endoAVF creation using the WavelinQ™ EndoAVF System at a University Hospital between December 2021 and August 2023.

RESULTS

A total of 20 patients who underwent an endoAVF were included. Technical success was 100%. In total, 75% (15) of the endoAVFs met the criteria for physiological suitability. The cannulation rate was 66% (10/15) for endoAVFs that reached physiological suitability. At 6 months of follow-up, the primary and cumulative patency rates were 65% and 75%, respectively; at 12 months, these were 50% and 70%, respectively. Serious adverse events were not observed. The reintervention rate was 0.33 procedures/patient-year.

CONCLUSION

Based on our experience, creating AVFs using the WavelinQ 4-F EndoAVF System is safe and effective, with high technical success rates and acceptable patency and reintervention rates.

Sharp recanalization with transseptal needle for unsuccessful standard recanalization of chronic thoracic central vein occlusion in hemodialysis patients

BACKGROUND

Many cases of chronic thoracic central vein occlusion (CVO) fail to recanalize using the standard conventional guidewire technique. This study aims to present the outcomes of sharp recanalization with a transseptal needle in chronic thoracic CVO.

METHODS

This retrospective study involved 22 hemodialysis patients who developed clinical signs and symptoms of CVO, had unsuccessful conventional endovascular treatment using guidewire, and underwent sharp recanalization with a transseptal needle from January 2018 to December 2021. Demographic information of patients, technical success rate, and complications were kept. Post-intervention primary patency rate was examined using survival regression.

RESULTS

Thirteen men and nine women were enrolled with a median age of 50 years (range: 30-83 years). The most common site of thoracic CVO was the right brachiocephalic vein (21 patients). The average length of occlusion was 2.5 cm (range: 1-4.4 cm). Technical success rate was 90.9% (20 patients). Major complications occurred in three instances, including severe hemothorax and pulmonary edema. The median post-intervention primary patency between balloon angioplasty alone and primary stenting was 2.1 and 8.0 months (p = 0.015). Post-intervention primary patency rates at 6 and 12 months in the group receiving balloon angioplasty alone versus primary stenting were 33.3% and 0% versus 70.6% and 29.4% (p = 0.013).

CONCLUSION

Sharp recanalization with a transseptal needle is successful in chronic thoracic CVO cases that fail with conventional recanalization. Primary stenting in this CVO lesion shows a greater primary patency compared to balloon angioplasty alone.

Vascular access hands-on training for young nephrologists: The fellows' experience of the N-PATH project REVAC module

Chronic kidney disease is a major public health problem, as population studies record a prevalence of 7.2% in individuals over 30 years and is expected to increase in the future. Many of them will end up undergoing hemodialysis treatment, and vascular access is not only an essential requirement for the technique, but also a determining factor in their prognosis; for all these reasons, every nephrologist should have both theoretical and practical knowledge of vascular access; however, the practical training is generally uneven and dependent on the hospital in which you train. It is within this context that the N-PATH (Nephrology Partnership for Advancing Technology in Healthcare) program was born with the objective of training 40 young European nephrologists in theoretical and practical aspects of Interventional Nephrology. To fulfill its mission, the 2-year program is composed of four modules of 6 months each including theoretical courses and hands-on training: Renal Expert in Molecular Pathology (REMAP), Renal Expert in Vascular Access (REVAC), Renal Expert in Medical Ultrasound (REMUS), and Renal Expert in Peritoneal Dialysis (REPED). By bringing together young nephrologists from all over Europe, the goal is also to create a strong network and promote Nephrology career at the European level. This publication highlights the experience of fellows who attended the REVAC hands-on training in Milan, focused on simulation and virtual reality for vascular access, and its impact on their nephrology training.

Editor's Choice - Outcomes of Cold Stored Saphenous Vein Allografts for Haemodialysis Vascular Access

OBJECTIVE

The aim of this study was to evaluate the outcomes of cold stored saphenous vein allografts (CSVAs) for haemodialysis vascular access.

METHODS

A retrospective, two centre study was conducted between January 2016 and December 2020 of all patients who had CSVA placement for haemodialysis vascular access. Primary, primary assisted, and secondary patency were analysed, as well as procedural complications and re-interventions.

RESULTS

One hundred and nine patients (n = 55 women) with a mean age of 67.2 ± 13.6 years, with no options for creating an autogenous arteriovenous fistula, were included in the study. At one year, primary, primary assisted, and secondary patency were 37.6%, 59.0%, and 73.3%, respectively; and at two years 19.9%, 42.5%, and 54.9%, respectively. During a mean follow up period of 26 ± 18 months, five patients (4.6%) had an access infection, with no related death. During the follow up period, 32 patients (29.4%) died and 13 patients (11.9%) underwent a kidney transplant. None of these patients showed immunoconversion before transplantation. The cumulative incidence of adverse events by the Fine-Gray method was calculated. Considering competing risks (death and renal transplantation), 9.2% of patients lost their vascular access at one year and 18% at two years. Moreover, 57.8% patients had stenosis, mainly on the outflow (45.9%), and 49.5% had thrombosis.

CONCLUSION

With a comparable patency rate associated with a low infection rate, CSVA offers a potential alternative to expanded polytetrafluoroethylene grafts. This creates haemodialysis vascular access when the venous capital is exhausted in patients with reported risk factors for vascular access infection, i.e., insertion in the thigh, advanced age, diabetes mellitus, immunocompromised state, obesity, or revision of an infected prosthetic graft.

Multi-Center Two-Year Patency Outcomes of Endovascular Arteriovenous Fistulas (endoAVF) Created with a 4 French System

PURPOSE

To assess multicenter two-year patency outcomes of endovascular arteriovenous fistulas (endoAVF) created with the WavelinQ device.

MATERIALS AND METHODS

Patients who had fistulas created at three centers from January 2018 to December 2020 were included in this retrospective study. In total, 112 patients underwent endoAVF creation [40 females, 72 males; mean age 60 years (range 18-88)]. Data collected included patient demographics, location of fistula creation, interventions performed, and brachial artery flows pre- and post-creation. Two-year cumulative patency, functional patency, and primary patency were assessed with Kaplan-Meier methodology. Factors affecting patency and maturation were examined using the Cox proportional hazards model.

RESULTS

Technical success defined as angiographically successful endoAVF creation was 97.3% (109/112). In 11 patients the fistula did not mature for dialysis use. For 98 patients (87%) with endoAVF maturation, 12- and 24-month cumulative patency was 94.3% and 91.7%. Functional patency (two-needle cannulation) at 12 and 24 months was 95.7% and 92.7%, respectively. Median maturation time is 95 days (IQR 51-231 days). Male gender and brachial vein coiling at the time of endoAVF creation were predictive of maturation. There were 34 censored events (four patients undergoing renal transplantation; 30 patients deceased). Number of reinterventions per patient year was 0.73 where 43 were maturation procedures and 101 were maintenance procedures. One Grade 3 complication occurred of arterial access puncture site pseudoaneurysm.

CONCLUSION

A high two-year functional and cumulative patency following endoAVF creation with the WavelinQ device was observed in this multicenter real-world experience Level of Evidence: 3 Level of Evidence III.

Two-Year Cumulative and Functional Patency after Creation of Endovascular Arteriovenous Hemodialysis Fistulae

PURPOSE

To assess 2-year cumulative and functional patency of endovascular arteriovenous fistulae (endoAVF) created with the WavelinQ device.

MATERIALS AND METHODS

Patients who had fistulae created at a single center from December 2019 to December 2020 were included in this retrospective study. Forty-three patients underwent endoAVF creation (22 females, 21 males). Data collected included patient demographics, location of fistula creation, interventions performed, and brachial artery flow before and after creation. Two-year cumulative and functional patency rates were assessed with Kaplan-Meier method, and variables that affected patency and maturation were examined using Cox proportional hazards model.

RESULTS

Technical success was 95% (41/43), and in 4 patients, the fistula did not mature for dialysis use (9.7%). For the remaining 37 patients with endoAVF maturation, 25 had ulnar-ulnar fistulae, 10 had radial-radial fistulae, and 2 had interosseous artery-vein fistulae. Mean maturity time was 73 days, and brachial artery flow of >886 mL/min was predictive of maturation. Mean tunneled dialysis catheter removal time was 133 days. Number of interventions per patient-year was 0.38, where 8 were maturation procedures (5 vein elevations/transpositions and 3 coil embolizations) and 21 were maintenance angioplasties. Two-year cumulative/secondary and functional patency rates were 89.4% and 92.1%, respectively, with a mean follow-up of 665.7 days. Examined variables did not impact cumulative or functional patency. One adverse event was migration of coil to the heart, which was successfully retrieved at time of procedure.

CONCLUSIONS

Two-year patency of 89.4% and functional patency of 92.1% were observed after endoAVF creation with WavelinQ device.

Vascular Access Outcomes in Patients with Autosomal Dominant Polycystic Kidney Disease

Key Points

More patients with autosomal dominant polycystic kidney disease received their first intervention to re-establish vascular access patency. Patients with autosomal dominant polycystic kidney disease do not require differential monitoring and treatment of hemodialysis vascular access.

Background

Autosomal dominant polycystic kidney disease (ADPKD) is a leading hereditary cause of ESKD, often using hemodialysis as a form of RRT. Patients with ADPKD may also present with extrarenal manifestations, including arterial aneurysms. The gold standard for hemodialysis access is an arteriovenous vascular access (VA), such as arteriovenous fistulas (AVFs) or arteriovenous grafts (AVGs). However, limitations, such as low VA flow and inadequate AVF outward remodeling, affect VA utilization. This study aimed to explore whether ADPKD affects patency rates of AVFs/AVGs in comparison with other underlying ESKD causes.

Methods

We conducted a retrospective cohort study using data from the Swedish Renal Registry from 2011 to 2020, with follow-up until 2022. We included 496 patients with ADPKD and 4321 propensity score–matched controls. VA patency rates of patients with ADPKD were compared with those of non-ADPKD patients using Kaplan–Meier survival curves and Mantel–Cox log-rank test. Interventions to maintain or restore patency were also analyzed.

Results

Patients with ADPKD constituted 8.0% of all patients, with a higher proportion in the pre-ESKD phase during VA creation (51.6% versus 40.6%). No significant differences were observed in primary, postcannulation primary, secondary, or functional patency between patients with ADPKD and non-ADPKD patients. However, more VAs were ligated in patients with ADPKD (10.5% versus 7.7%, P = 0.03), and they underwent more first interventions to re-establish flow (49.4% versus 41.9%, P = 0.02).

Conclusions

These findings suggest that AVF/AVG patency remains comparable in patients with ESKD with or without ADPKD, and VA monitoring and treatment strategies for patients with ADPKD should align with those for individuals with other ESKD causes.

Multi-perspective ultrasound evaluation of Carotid Intima-Media thickness in hemodialysis access patients and its possible use to predict clinical outcomes

BACKGROUND

Hemodialysis (HD) patients present an increased carotid intima-media thickness (CIMT) and calcified plaques, and studies have demonstrated that CIMT is predictor for cardiovascular death in this patient population; hence, the importance of identifying early non-invasive markers of atherosclerosis. We aim to propose a new three-perspective CIMT measuring method in HD population, and to further investigate the possible use and value of this method to predict outcomes.

METHODS

A cross-sectional study was conducted, the CIMT was measured with duplex ultrasound during the perioperative access planning. Software provided maximum CIMT in a 10 mm (mm) width of the common carotid artery. CIMT was measured in Right (R) and Left (L) carotid arteries, both in anterior (a), lateral (l), and posterior (p) view. The sum of these values (Ra+Rl+Rp+La+Ll+Lp) was completed and termed as Sixth Carotid Intimal (SCI) score. We stratified either in low (summation <4) or high (>=4) SCI score groups. Demographics, patency rates, complications, and mortality were collected; chi-square test was used for our analysis.

RESULTS

A total of 30 patients (mean age 49 years and 56% females) that underwent access creation in the upper arm from 2010 to 2016 were selected and studied. A low SCI score was found 19 patients and 11 had high SCI, no significant difference was observed in demographics, history cardiovascular disease, and clinical outcomes as early thrombosis, and primary, primary-assisted patency at 12 months. Interestingly, during the follow up period of 36 months a significant higher difference in late thrombosis rates occurred (63.6% vs 26.3%, p = .044) and a higher all-cause mortality (54.4% vs 15.7%, p = .025) in patients with SCI score group above 4.

CONCLUSIONS

The SCI score method, might offer a screening tool for traditional cardiovascular risk factors in HD patients. In this study, we demonstrate an increased rate in late thrombosis and mortality in those with high SCI. Further research is necessary to better define the role of CIMT in vascular surgical procedures.

Regulation of vascular remodeling by immune microenvironment after the establishment of autologous arteriovenous fistula in ESRD patients

Autogenous arteriovenous fistula (AVF) is the preferred dialysis access for receiving hemodialysis treatment in end-stage renal disease patients. After AVF is established, vascular remodeling occurs in order to adapt to hemodynamic changes. Uremia toxins, surgical injury, blood flow changes and other factors can induce inflammatory response, immune microenvironment changes, and play an important role in the maintenance of AVF vascular remodeling. This process involves the infiltration of pro-inflammatory and anti-inflammatory immune cells and the secretion of cytokines. Pro-inflammatory and anti-inflammatory immune cells include neutrophil (NEUT), dendritic cell (DC), T lymphocyte, macrophage (Mφ), etc. This article reviews the latest research progress and focuses on the role of immune microenvironment changes in vascular remodeling of AVF, in order to provide a new theoretical basis for the prevention and treatment of AVF failure.

Risk factors for in-stent restenosis in maintenance hemodialysis patients with central venous occlusive disease and biomechanical assessment of stents

OBJECTIVES

To investigate the risk factors and biomechanical mechanisms of in-stent restenosis (ISR) in central venous occlusive disease (CVOD).

PATIENTS AND METHODS

This retrospective study consecutively included 77 maintenance hemodialysis (MHD) patients with CVOD who received the first percutaneous transluminal angioplasty with stenting (PTS) due to symptomatic CVOD in a tertiary hospital. The mean age was 59.7 ± 14.0 years, and 51.9% of patients were male. The clinical characteristics, occurrence of ISR and patency rates were recorded. Finite element method was applied to assess the biomechanical properties of stents.

RESULTS

Among 77 patients with a mean CVS score of 8.0 ± 2.8, 20.8%, 62.3%, and 16.9% of patients had the main vein of CVOD in the subclavian vein, brachiocephalic vein, and superior vena cava, respectively. A total of 72 (93.5%) patients received successful PTS treatment, for which the stents implanted were mainly Fluency covered stent (48.6%) and SMART bare stent (31.9%). During 15 (10-24)-months of follow-up, ISR occurred in 36.1% of the 72 patients. The primary and assisted primary patency rates at 6, 12, and 18 months were 78%, 56%, 42% and 95%, 90%, 87%, respectively. A prolonged dialysis vintage was an independent risk factor for ISR, yet the stent type or the main vein location was not correlated with ISR. Among three laser-engraving stents, the SMART stent was the best in terms of flexibility, stress, and strain on stents but worst in stress or strain on vessels. The Luminexx stent was the best in radial force and worst in stress or strain on stents. The Vici stent was the best in stress and strain on vessels and worst in radial force and flexibility.

CONCLUSIONS

An unsatisfactory comprehensive biomechanical performance from configurations rooted in existing stents may account for the high incidence of ISR in CVOD.

Outcomes of stent grafts for treatment of central venous disease in hemodialysis patients

BACKGROUND

To evaluate the effectiveness of stent graft (SG) for the treatment of central venous disease (CVD) in hemodialysis patients.

METHODS

Between January 2014 and April 2022, 122 patients on hemodialysis with symptomatic CVD were treated with percutaneous transluminal angioplasty (PTA) and bare-metal stent (BMS) or SG placement. The mean follow-up was 14.5 months (IQR: 8.0, 24.2). Patency rates of the target sites were calculated using Kaplan-Meier and log-rank studies. Multivariate Cox proportional hazard models were used to evaluate the association between various characteristics and target site primary patency.

RESULTS

Technical success rate was 100%. At 3, 6, 12, and 24 months, the target sites primary patency rates were 86.4%, 74.2%, 45.1%, and 30.4% for PTA; 94.7%, 78.6%, 60.8%, and 45.6% for BMS; and 94.0%, 92.0%, 82.4%, and 66.8% for SG, respectively, and the assisted primary patency rates were 86.5%, 80.4%, 63.8%, and 46.0% for PTA; 94.7%, 89.5%, 77.5%, and 71.1% for BMS; 100%, 100%, 97.8%, and 83.4% for SG, respectively. The Kaplan-Meier analysis indicated that SGs achieved better primary and assisted primary patency than PTA or BMS (p<0.05). SG use and concomitant stenosis were the independent predictors of target site primary patency dysfunction in the multivariate analysis.

CONCLUSIONS

This study confirmed the better long-term patency of SG in comparison with PTA and BMS for the treatment of CVD in hemodialysis patients.

Effect of insertion site on tunnelled haemodialysis catheter outcomes: an observational study of 967 catheters

BACKGROUND

The right internal jugular vein is the preferred approach to tunnelled haemodialysis catheter placement. However, the effect of the insertion site on long-term catheter outcomes remains uncertain.

AIMS

We aimed to analyse a large cohort of tunnelled haemodialysis catheter placements to compare short-term and long-term results according to central venous catheter location.

METHODS

A retrospective cohort study was performed on consecutive tunnelled catheter insertions at two centres over 7 years. The primary outcome was catheter survival, compared according to the central vein site. We used the Kaplan-Meier curve method and Cox proportional hazards modelling to determine the effect of the catheterisation route on primary patency, adjusted for clinical risk factors for catheter failure.

RESULTS

There were 967 tunnelled dialysis catheter placements in 620 patients. The median survival for right internal jugular vein catheters was 569 days. There were no differences in rates of catheter failure between right internal jugular, left internal jugular (adjusted hazard ratio [HR], 0.80; 95% confidence interval [CI], 0.52-1.21), external jugular (HR, 0.79; CI, 0.33-3.13), subclavian (HR, 0.67; CI, 0.58-2.44) and femoral vein (HR, 1.20; CI, 0.36-1.33) catheters following multivariable analysis. There were no major differences in functionality or complications between the groups.

CONCLUSIONS

This study identified no statistically significant relationship between tunnelled haemodialysis catheter insertion site and catheter survival. The contemporary approach to dialysis vascular access should be tailored to specific patient circumstances.

Effect of two different techniques of arteriovenous fistula puncture on wound infection in haemodialysis patients

Safe and effective arteriovenous fistula (AVF) puncture is very important to reduce the wound complications of haemodialysis (HD). For AVF puncture in dialysis patients, there is a lack of clarity and consistency regarding the relative advantage of buttonhole (BH) over rope-ladder (RL) cannulae in terms of wound complications. The study was published in several scientific databases including Cochrane Library, PubMed and Embase by October 2023. Data from all controlled trials looking at the effect of BH and RL on wound complications in haemodialysis patients were included. The articles were written in English, and they were about adult who had AVF while on dialysis. Studies with or without BH or RL treatment were excluded from the analysis. The data was analysed with RevMan5.3 software. Out of 215 trials, 9 were chosen for the final analysis. The study publication dates were between 2000 and 2023. Of these, 17 326 patients received AVF therapy. Among them, there were 3070 BH and 14 256 RL. In 9 studies, RL had a lower risk of postoperative wound infection compared to BH (OR, 3.38; 95% CI, 3.06, 3.73 p < 0.0001); In all 3 studies, there were no statistically significant differences in the risk of post operative bleeding in RL versus BH(OR, 0.76; 95% CI, 0.25, 2.33 p = 0.63). Our studies have demonstrated that RL trocars are superior to BH trocars in the prevention of wound infection.

Small Oversized Stent Graft Is Associated With Increased Patency for the Treatment of Central Venous Disease in Hemodialysis Patients

PURPOSE

The purpose of this study was to identify the independent predictors of higher patency rates and investigate the selection of specifications of stent graft in the treatment of central venous disease.

MATERIALS AND METHODS

This retrospective study included 54 patients who underwent stent-grafts' placement for the treatment of central venous disease between March 2017 and September 2022 at a tertiary hospital. The demographic data for the patients and the clinical data of the treated lesions were collected and analyzed. The patency rates of the treated lesions with different oversizing range were calculated via the Kaplan-Meier and log-rank analyses. The multivariate Cox proportional hazard models were constructed to identify the independent predictor of the target site primary patency.

RESULTS

The median follow-up period was 21.5 months. The primary patency rates of the target sites were 90.7%, 72.2%, and 55.1% at 6, 12, and 24 months, respectively. The assisted primary patency rates of the lesions were 96.3%, 92.5%, and 80.3% at 6, 12, and 24 months, respectively. The log-rank analysis showed that the stent-grafts' placement with small oversizing had significantly higher primary patency rates than those with large oversizing (p=0.022). The multivariate analysis revealed that concomitant stenosis and large oversizing stent graft were the independent predictors of target site primary patency.

CONCLUSIONS

Stent grafts showed reasonable primary patency for the treatment of central venous disease in hemodialysis patients. A stent graft with small oversizing is associated with better target site primary patency rates than those with large oversizing.

CLINICAL IMPACT

Stent grafts showed reasonable primary patency for the treatment of central venous disease in hemodialysis patients. Few studies, however, have explored the efficiency of stent grafts to treat CVD by considering different factors such as sizing considerations, the rate of oversizing percentage, etc. A stent graft with small oversizing is associated with better target site primary patency rates than those with large oversizing. Excessive oversizing should be avoided to prevent infolding or stent collapse.

Fully no-touch technique without inflating the cephalic vein increase the patency rate of arteriovenous fistulas

INTRODUCTION

One of the most important problems for patients undergoing hemodialysis due to chronic renal failure is the need for a long-lasting vascular access. The patency of vascular access is affected by many factors. Factors related to surgery are also among these factors. No-touch techniques theoretically and practically prevent endothelial damage due to minimal contact on vascular structures. It is a well-known fact that surgeries performed with these methods also increase long-term survival.

METHODS

Patients who underwent distal radiocephalic arteriovenous fistula (AVF) surgery for the first time between 2017 and 2021 were included in our study. The groups, whose cephalic veins were inflated conventionally and not inflated, were compared in a prospective randomized manner.

RESULTS

There was a significant difference between both groups in terms of failure and patency rates, which is one of the study endpoints (p = 0.012). The fact that the patency period is long, and the failure rate is low stands out as the superiority of the fully no-touch technique in AVF surgery. On the other hand, no significant difference was observed in terms of failure to maturation and fistula maturation time.

CONCLUSIONS

Fully no-touch technique in AVF surgery should be considered primarily in suitable patients due to its long patency time and low failure rate.

Low Posterior Internal Jugular Vein Approach for Tunnelled Haemodialysis Catheter Insertion: A Report on Outcomes at a Single Centre

AIM

The impact of technical differences in cannulation technique for tunnelled haemodialysis catheter insertion is undetermined. We aimed to assess clinical outcomes of the low posterior approach for internal jugular vein tunnelled catheter placement.

METHODS

A retrospective audit was undertaken on consecutive tunnelled catheter procedures performed at a single centre between January 2016 and June 2022. Only catheters specifically placed with a low posterior internal jugular approach were included. The study's primary outcome was 12-month catheter survival, evaluated using the Kaplan-Meier survival curve and log-rank test. Secondary outcomes included catheter performance and procedure-related complications.

RESULTS

During the study period, 391 tunnelled internal jugular haemodialysis catheters were inserted in 272 patients using the low posterior technique. The 12-month primary patency rate was 68%. Catheter insertion was successful in 96% of cases. Peri-procedural complications occurred in 4% of cases, most frequently bleeding. The most common reasons for catheter loss were dysfunction (10%) and bacteraemia (6%). The best predictors of catheter failure were advanced age (HR 1.02, 95% CI 1.00-1.04) and in-centre dialysis treatment locality (HR 2.04, 95% CI 1.19-3.45).

CONCLUSION

The low posterior approach for internal jugular vein tunnelled catheter insertion is effective and safe. We demonstrated a 12-month catheter survival rate of 68%. Further research comparing the low posterior approach with other internal jugular vein cannulation techniques is warranted.

Efficacy and Safety of Sharp Recanalization with the Stiff End of a Microguidewire for Treatment of Refractory Central Venous Occlusions in Hemodialysis Patients

BACKGROUND

Sharp recanalization is a viable procedure for some refractory central venous occlusions that cannot be recanalized with the conventional technique. The sharp recanalization procedures reported in previous studies are often rely on costly devices and with a certain proportion of complications. This study aimed to present an inexpensive and risk-controllable coaxial centrifugally sharp recanalization technique that was independent of any additional costly devices.

METHODS

This retrospective study enrolled 8 patients who had received sharp recanalization of central venous occlusions, between August 2017 and May 2021. The sharp recanalization technique was performed centrifugally with the stiff end of a microguidewire after the lesions failed to be passed through with the conventional technique. Clinical data of patients on their lesions, technical success rate, procedure-related complications, and patency rates were collected and analyzed to assess the efficacy and safety of the technique.

RESULTS

Technical success was achieved in all patients, with no complications were observed. All symptoms were ameliorated within 48h postsurgery. The median follow-up period was 22 months. All patients maintained patency or assisted patency at 12 month follow-up.

CONCLUSIONS

Sharp recanalization performed centrifugally with the stiff end of the microguidewire could be a cost-effective and safe alternative procedure for the treatment of refractory central venous occlusion that cannot be recanalized with conventional technique.

Patency of Drug-Coated versus Conventional Balloon Angioplasty for Hemodialysis Access Stenosis

Purpose

This study aimed to evaluate the post-intervention target primary patency of drug-coated balloon angioplasty (DCBA) compared with conventional balloon angioplasty (CBA) in the treatment of the dysfunctional autogenous arteriovenous fistula (AVF) in a real-world clinical setting.

Materials and Methods

This retrospective study included 24 patients with end-stage renal disease, who developed dysfunctional AVF during hemodialysis, and underwent endovascular treatment using CBA and DCBA from January 1, 2014, to June 30, 2021. The demographic data of patients and details regarding their fistula were recorded. Post-intervention target primary patency was analyzed.

Results

Sixteen men and 8 women with an average age of 63.9 ± 14.2 years, who underwent 333 endovascular treatments in 57 target lesions of access were enrolled. DCBA was a protective factor for the treatment of a target lesion of dysfunctional access with an adjusted hazard ratio of 0.725 (95% confidence interval [CI]: 0.528-0.996; P = 0.047). According to the Weibull proportional hazards regression model, DCBA showed a longer post-intervention target primary patency than CBA.

Conclusion

DCBA has better outcomes in terms of post-intervention target primary patency in the real-world treatment of dysfunctional autogenous AVF.

The RADAR technique in reconstruction of failed autologous arteriovenous fistulas due to juxta-anastomotic stenosis is equivalent to that with traditional surgery in maintenance hemodialysis patients

OBJECTIVE

Autologous arteriovenous fistula (AVF) is recommended as superior vascular access for hemodialysis but has a high rate of failure, and juxta-anastomotic stenosis (JAS) is one of the predominant causes of fistula failure. The aim of this study was to compare the primary patency in reconstruction of failed AVFs due to JAS between the radial artery deviation and reimplantation (RADAR) technique and traditional surgery (end-vein to side-artery neo-anastomosis) in maintenance hemodialysis (MHD) patients.

METHODS

A total of 1215 MHD patients with failed AVF were enrolled in this retrospective cohort study, and 614 patients with failed AVF received surgical intervention. Among these surgical interventions, 417 patients experienced AVF failure due to JAS. Finally, 25 patients who received the RADAR technique were enrolled. Controls of 50 patients received traditional surgery were randomly selected matched by age and sex. Clinical data such as age, sex, comorbidities, and blood biochemical indices were collected. Kaplan-Meier survival curves and Cox proportional hazards analyses were used to explore the difference between the RADAR group and the traditional group in reconstruction of failed AVFs.

RESULTS

The RADAR group and the traditional group shared common baseline characteristics. The primary patencies of the reconstructed AVFs were 88.8%, 79.0%, 72.2%, 57.4%, and 38.3% at 12, 24, 36, 48, and 60 months among the 75 patients, respectively. Kaplan-Meier survival curve analysis demonstrated similar primary patencies in the two groups (log-rank test, p = 0.73). Compared with the traditional group, the RADAR group had no difference in predicting AVF failure after adjusting for potential confounders, with an HR of 0.92 (95% CI, 0.18-4.63).

CONCLUSIONS

The primary patency of the RADAR technique and the traditional surgery in the reconstruction of failed AVFs due to JAS is almost equal in 5 years.

Results of a hemodialysis vascular access routine ultrasound surveillance protocol and frequency of surveillance guided pre-emptive access maintenance interventions

BACKGROUND

To evaluate the implementation of routine surveillance using ultrasound on hemodialysis vascular access (VA) outcomes and determine the number and frequency of corrective, surveillance-guided procedures performed.

METHODS

Multicenter, prospective, observational study that includes consecutive hemodialysis patients receiving therapy from native arteriovenous fistulae (AVF) or grafts (AVG). Participants were assigned to a routine VA Color Doppler ultrasound surveillance (DUS) protocol from January 2019 to December 2021. Patients were referred for corrective procedures (endovascular or surgical) based on clinical or DUS findings (pre-emptive procedures; PEP). Primary endpoint was the estimation of primary unassisted (PUP) and secondary patency (SP) rates. Secondary endpoints were the determination of the number and frequency of PEP and VA survival rates.

RESULTS

In total, 223 patients with 243 VA (192 AVF and 51 AVG) were included. Access PUP and SP rates were 83% and 93% at 12 months, 75% and 88% at 24 months, and 72% and 83% at 36 months follow-up. Autologous fistulae PUP and SP were 89% and 96% at 12 months, 81% and 93% at 24 months, and 80% and 89% at 36 months, respectively. Graft PUP and SP were 56% and 80% at 12 months, 44% and 65% at 24 months, and 39% and 54% at 36 months, respectively. In total, 56 corrective procedures (38/56 PEP; 65.5%) were performed (0.13 procedures/year), of which 34 were in AVF patients (0.09 procedures/year) and 22 in AVG patients (0.40 procedures/year). Overall, 33 VA losses occurred (0.06 failures/year), 17 in AVF (0.04 failures/year), and 16 in AVG patients (0.20 failures/year).

CONCLUSION

The use of DUS resulted in the timely diagnosis of dysfunction, satisfactory overall VA survival, and patency rates, with a low PEP frequency. Randomized controlled trials are required to establish the value of DUS surveillance on access patency and whether DUS-guided interventions could improve VA outcomes.

ACR Appropriateness Criteria® Dialysis Fistula Malfunction

The creation and maintenance of a dialysis access is vital for the reduction of morbidity, mortality, and cost of treatment for end stage renal disease patients. One's longevity on dialysis is directly dependent upon the quality of dialysis. This quality hinges on the integrity and reliability of the access to the patient's vascular system. All methods of dialysis access will eventually result in dialysis dysfunction and failure. Arteriovenous access dysfunction includes 3 distinct classes of events, namely thrombotic flow-related complications or dysfunction, nonthrombotic flow-related complications or dysfunction, and infectious complications. The restoration of any form of arteriovenous access dysfunction may be supported by diagnostic imaging, clinical consultation, percutaneous interventional procedures, surgical management, or a combination of these methods. This document provides a rigorous evaluation of how variants of each form of dysfunction may be appraised and approached systematically. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Performance Characteristics of Candidate Criteria for Hemodialysis Arteriovenous Fistula Maturation

BACKGROUND

Twenty to 60% of newly created hemodialysis arteriovenous fistulas do not mature adequately for use. One barrier to developing interventions to improve fistula outcomes is a lack of standardized criteria for maturation.

METHODS

Using data from the multicenter, prospective Hemodialysis Fistula Maturation (HFM) Study, we determined sensitivities, specificities, and positive and negative predictive values of multiple candidate maturation criteria using the HFM Study maturation criteria as the reference. We also compared, across the maturation criteria, relationships between maturation and fistula survival using Cox proportional hazards models.

RESULTS

We included 535 of the 602 HFM Study participants. The median (interquartile range) age was 57 (47-65) years, 70% were men, and 45% were Black participants. Depending on the criterion and time frame for ascertainment (3, 4, 5, 6, or 9 months), sensitivities ranged from 57% to 100%, specificities ranged from 85% to 100%, positive predictive values ranged from 88% to 100%, and negative predictive values ranged from 65% to 100%. For all criteria, areas under the curve for the 6-month (0.90-0.97 for unassisted maturation and 0.89-0.95 for overall maturation) and 9-month time frames were similar. Attainment of unassisted maturation was associated with lower risks of fistula abandonment, with hazard ratios ranging from 0.10 to 0.40 depending on the criterion and time frame. Eliminating dialysis adequacy indicators, or simplifying the criteria in other ways, had little effect on performance characteristics.

CONCLUSIONS

High performance characteristics are maintained with maturation criteria that are simpler and less burdensome to ascertain than the HFM Study outcome measure.

Functional patency rates of arteriovenous fistula of a retrospective cohort study from one of the biggest centers in Canada

BACKGROUND

The main barriers to arterio-venous fistula (AVF) utilization are primary failure, long maturation duration, and low secondary patency rates.

METHODS

In this retrospective cohort study, primary, secondary, functional primary, and functional secondary patency rates were calculated and compared between two age groups (< 75 years and >  = 75 years) and between radiocephalic (RC-) and upper arm (UA-) AVFs, and factors determining the duration of functional secondary patency were evaluated.

RESULTS

Between 2016 and 2020, 206 predialysis patients whose AVFs had been created previously initiated renal replacement treatment. RC-AVFs comprised 23.3% and were created after favorable analysis of the forearm vasculature. Overall, the primary failure rate was 8.3, and 84.7% started hemodialysis with a functioning AVF. Functional secondary patency rates of primary AVFs were better with RC-AVFs [1,3 and 5 year rates of 95.8, 81.9 and 81.9% versus 83.4, 71.8 and 59.2% for UA-AVFs (log rank p: 0.041)]. There was no difference between the two age groups for any of the AVF outcomes assessed. Among patients whose AVF was abandoned, 40.3% had gone on to have a second fistula created. This was significantly less likely in the older group (p < 0.01).

IN CONCLUSION

(1) UA-AVFs were placed more commonly than RC-AVFs; (2) a selection bias existed whereby RC-AVFs were only created after favorable forearm vasculature was demonstrated or suspected; (3) superior functional secondary patency rates were observed with RC-AV's, perhaps stemming from this selection bias; (4) the elderly were more likely to have only one AVF creation attempt.

Systematic review and meta-analysis of preoperative interventions to support the maturation of arteriovenous fistulae in patients with advanced kidney disease

BACKGROUND

There is great potential to improve outcomes of arteriovenous fistulas (AVFs) by focusing more on the preoperative period of AVF creation. We aim to systematically review the evidence on safety and efficacy of various preoperative interventions that have been tried to improve AVF maturation and success rate.

METHODS

We searched five databases: PubMed, Embase, CINAHL, Cochrane Library and King's Fund Library. Experimental studies that investigated the effect of various preoperative interventions to improve AVF outcomes among advanced chronic kidney disease (CKD) patients were searched. The effect size for primary outcome was calculated as the weighted mean difference in the final vessel calibre, rate of AVF maturation or primary failure between the intervention and control arm. We also assessed adverse effects and dropout rates. This review was preregistered in the International Prospective Register of Systematic Reviews (CRD42020193257).

RESULTS

Eight eligible studies were identified involving three types of intervention: hand exercise (n = 6), cholecalciferol supplementation (n = 1) and pneumatic compression of the arm using a Fist Assist device (n = 1). The overall effect size of hand exercise on distal cephalic vein calibre was 0.24 mm [95% confidence interval (CI) 0.03-0.45] on meta-analysis of hand exercise studies. On restricting analysis to two randomized controlled trials (RCTs) that had independent control groups, the effect size was higher, at 0.29 mm (95% CI 0.11-0.47). Hand exercise was a well-tolerated intervention, especially when confined to the first 4 weeks.

DISCUSSION

Hand exercise is the predominant intervention tried in the preoperative period of AVF creation, although there is methodological heterogeneity. Intermittent pneumatic compression using a Fist Assist device is a novel intervention that has shown some promise. Well-designed prospective RCTs are needed on preoperative interventions among advanced CKD patients, aimed at improving AVF outcomes.

Analysis of patency rates and factors associated with arteriovenous fistula in maintenance hemodialysis patients followed for 10 years

OBJECTIVE

This study analyzed the long-term arteriovenous fistula (AVF) patency rate and its determinants in patients undergoing maintenance hemodialysis.

METHODS

General data and laboratory examinations of hemodialysis patients were collected retrospectively. The primary patency time, primary functional patency time, cumulative patency time, cumulative functional patency time, and temporary central venous catheterization (CVC) time were counted. Cox regression was used to analyze the relationships between different factors and AVF survival time. Kaplan-Meier survival analysis was used to analyze the primary patency, primary functional patency, cumulative patency, and cumulative functional patency rates between different groups.

RESULTS

A total of 174 patients were included (mean age 58.38 ± 15.35 years), 57 women (32.76%) and 68 diabetics (39.08%). Univariate and multivariate Cox regression showed a correlation between UCR and AVF primary patency time, primary functional patency time, cumulative patency time, and cumulative functional patency time (HR 1.127, 1.116, 1.127, 1.115, 1.088, 1.075, 1.087, 1.013; 95%CI 1.055-1.204, 1.043-1.194, 1.055-1.204, 1.042-1.194, 1.022-1.158, 1.006-1.149, 1.021-1.157, 1.004-1.147; p < 0.001, 0.001, <0.001, 0.002, 0.008, 0.033, 0.009, 0.039, respectively). Duration of temporary CVC was also correlated (HR 1.013, 1.013, 1.013, 1.014, 1.008, 1.008, 1.008, 1.008; 95%CI 1.007-1.018, 1.008-1.019, 1.008-1.019, 1.009-1.020, 1.004-1.012, 1.004-1.012, 1.004-1.012, 1.004-1.012; p < 0.001, <0.001, <0.001, <0.001, <0.001, <0.001, <0.001, <0.001, respectively). Female sex was correlated with the primary patency time and the primary functional patency time (HR 1.755, 1.765, 1.767; 95%CI 1.028-2.997, 1.034-3.014, 1.021-3.057; p = 0.039, 0.037, 0.042, respectively), but not with the cumulative patency time and the cumulative functional patency time, the primary patency rate and primary functional patency rate of AVF were higher in male than in female patients (χ2 = 4.439, 4.531; p = 0.035, 0.033, respectively). The primary patency rate, primary functional patency rate, cumulative patency rate, and cumulative functional patency rate of AVF with UCR > 10.11 group are lower than those with UCR ≤ 10.11 (χ2 = 10.745, 10.712, 4.605, 4.472; p = 0.001, 0.001, 0.032, 0.034, respectively). The group of DTCP ≤ 42 days is better than DTCP > 42 days (χ2 = 6.014, 6.055, 8.572, 8.461; p = 0.014, 0.014, 0.003, 0.004, respectively).

CONCLUSION

Women with high UCR values at the beginning of dialysis and a long duration of temporary CVC have a poor long-term survival rate of AVF. Therefore, UCR can be used as an indicator to predict the long-term survival rate of AVF. Simultaneously, clinicians should remove the temporary catheter as early as possible if conditions permit it.

Cannulation Technique of Vascular Access in Hemodialysis and the Impact on the Arteriovenous Fistula Survival: Systematic Review and Meta-Analysis

Adequate cannulation technique (CT) methods and successful puncture are essential for hemodialysis (HD) and arteriovenous fistula (AVF) maintenance. This systematic review and meta-analysis was designed to identify which CT allows better AVF primary patency and lower rates of complications in HD patients. The search was carried out on the CINAHL, MEDLINE, Cochrane Library, and Joanna Briggs Institute Library databases to identify all randomized controlled trials (RCTs) and observational studies comparing clinical outcomes of buttonhole (BH) versus rope ladder cannulation (RL) from 2010 to 2022. The Risk-of-Bias (Rob 2) tool was used for RCTs and the ROBINS-I was used for non-randomized studies. RevMan 5.4 was used for the meta-analysis. A total of five RCTs, one quasi-randomized controlled trial, and six observational studies were included. When compared with RL cannulation, BH cannulation significantly increased bacteremia (RR, 2.76, 95% CI (1.14, 6.67), p = 0.02) but showed no differences in AVF primary patency (HR, 1.06, 95% CI (0.45, 4.21), p = 0.90). There was no thrombosis reduction (RR, 0.51, 95% CI (0.23, 1.14), p = 0.10) or intervention number reduction (RR, 0.93, 95% CI (0.49, 1.80), p = 0.84) with BH. Outcomes like pain, hematoma, and aneurism could not be merged due to a lack of data, reported as medians, as well as due to different definitions. The quality in general was poor and the heterogeneity among the studies prevented us from merging the outcomes.

Early Follow-Up after Arteriovenous Fistula Creation is Associated with Improved Access-Related Outcomes

BACKGROUND

Up to 60% of arteriovenous fistulas (AVF) require intervention to assist maturation, which prolongs the time until it can be used for hemodialysis (HD). Current guidelines recommend early postoperative AVF examination to detect and address immaturity to decrease time to maturation. This study evaluates how the timing of postoperative follow-up to assess AVF maturity affects patients' outcomes.

METHODS

All patients who underwent AVF creation between 2017 and 2021 in an academic medical center were retrospectively reviewed, excluding patients lost to follow-up or not on HD. Outcomes were compared between patients that had delayed follow-up to assess AVF maturity, >8 weeks post surgery, versus early follow-up, <8 weeks post-surgery. AVF evaluation for maturity consisted of physical examination and duplex ultrasound. Primary endpoints were time to first cannulation (interval from AVF creation to first successful cannulation) and time to catheter-free dialysis (interval from AVF creation to central venous catheter removal).

RESULTS

A total of 400 patients were identified: 111 in the delayed follow-up group and 289 in the early follow-up group. The median time to follow-up was 78 days (interquartile range [IQR], 66-125) in the delayed follow-up group versus 39 days (IQR, 36-47) in the early follow-up group, (P < 0.0001). The maturation rate was 87% in the delayed follow-up group versus 81% in the early follow-up group, (P = 0.1) and both groups had similar rates of interventions to assist maturation (66% vs. 57%, P = 0.2). The early follow-up group had a significantly shorter median time to first cannulation (50 vs. 88 days; P < 0.0001) and shorter time to catheter-free HD (75 vs. 118 days; P <0.0001). At 4 months after AVF creation, the incidence of first cannulation was 74% in the early follow-up group versus 63% in the delayed follow-up group (P = 0.001). Similarly, the incidence of catheter-free dialysis was 65% in the early follow-up group versus 50% in the delayed follow-up group at 4 months postoperatively, (P = 0.036).

CONCLUSIONS

Early postoperative follow-up for evaluation of fistula maturation is associated with reduced time to first successful cannulation of AVF for HD and reduced time to catheter-free dialysis.

Vein and artery diameter influence on arteriovenous fistula maturation and patency in a Mexican population

BACKGROUND

There is no consensus of the optimal arterial and venous sizes on arteriovenous fistula (AVF) function and patency. The purpose of our study was to determine the influence of vein and artery sizes on maturation and patency in autologous first time AVF in a vascular access clinic of Mexican Social Security.

METHODS

Approved IRB single-center retrospective study in patients referred for their first AVF from 01/2018/ to 04/2020. Perianastomotic inner vein diameter and single inner artery diameter was recorded by duplex ultrasound. Outcomes were: failure to mature (FTM) and cumulative primary patency survival.

RESULTS

Eighty-six AVF's were created (mean age 45.5 ± 15.1 years; 62.8% male; mean BMI 25.9 ± 4.3 kg/m2). About 86% were brachiocephalic AVF. Eight (8.1%) AVF had FTM. Mean follow-up was 19.7 ± 8.5 months. Two-year patency survival was 81.4%. FTM vein and artery diameters (2.1 ± 0.3 and 2.8 ± 0.7 mm respectively) were smaller than successful AVF's (3.1 ± 0.9 and 3.5 ± 0.6 mm) (p < 0.05). ROC curve calculated a 2.15 mm vein diameter cutoff (AUC: 0.86) and a 2.95 mm artery diameter cutoff (AUC: 079) for FTM AVF's (83% sensitivity, 72% specificity both) (p < 0.05). AVF's created with a vein diameter <2.15 mm and <2.95 mm artery diameter had statistically significant lower patency survival than AVF's with larger vein and artery diameters (p < 0.05).

CONCLUSION

Vein diameter <2.15 mm and artery diameter <2.95 mm influences AVF maturation and patency in a Mexican population.

Tunneled femoral dialysis catheter: Practical pointers

One of the most challenging aspects of providing end-stage kidney disease care is to achieve adequate long-term access to the bloodstream to support hemodialysis (HD) therapy. Although upper extremity arteriovenous fistula remains the vascular access of choice for patients on HD, complications such as central venous stenosis, access thrombosis, or exhaustion of suitable access sites in the upper extremity, ultimately result in pursuing vascular access creation in the lower extremity. The current review focuses on the indications, contraindications, and clinically relevant practical procedural tips to successfully place a tunneled femoral dialysis catheter. The review highlights some of the prevailing misconceptions regarding femoral catheter placement practices.

Mid-term cumulative patency of fistula and PTFE grafts among hemodialysis patients: A retrospective, single-center study from Palestine

BACKGROUND

Due to the long waiting time for kidney transplantation, most End-Stage renal disease patients are commenced on either hemodialysis or peritoneal dialysis. Reusable fistulas have the lowest risk for death, cardiovascular events, and infections among all vascular accesses. This study aims to report the outcomes of the arteriovenous fistulas and PTFE grafts and the related predictive clinical and demographic variables.

METHODS

This retrospective study reviewed the charts of all hemodialysis patients between January 2017 and January 2021 at the Dialysis Center of An-Najah National University Hospital, Nablus, Palestine. Our outcomes were a primary failure, primary and secondary patency, and the related factors. Survival analysis using the Kaplan-Meier method was conducted, and the log-rank test was used to compare patency rates. The Cox proportional hazards regression model tested factors relevant to primary and secondary patency rates in univariate and multivariate analyses.

RESULTS

A total of 312 procedures were performed during the study period. Primary failure was 7.1% for AVF, 13.9% for arterio-venous graft (AVG) procedures. Peripheral arterial disease and left-sided AVF were associated with more primary failure rates. AVF, primary patency rates at 1, 2, and 3 years were 82%, 69%, and 59%, respectively, while secondary patency rates at 1, 2, and 3 years were 85%, 72%, and 63%, respectively. Factors associated with increased AVF patency in a proportional hazard model were younger age and dual antiplatelet administration.

CONCLUSION

Our study adds further evidence that autogenous AVF has better results than prosthetic AVG in both primary and secondary patency rates as well as less primary failure rates. Therefore, we encourage further longitudinal studies that assess the benefits of using antiplatelet on AVF outcome versus risks of bleeding, especially with dual agents.

A systematic review aggregated data and individual participant data meta-analysis of percutaneous endovascular arteriovenous fistula

OBJECTIVE

To assess the short-term and mid-term safety and efficacy of percutaneous endovascular arteriovenous fistula (pAVF) creation.

METHODS

A systematic search was implemented corresponding to the PRISMA 2020 and the PRISMA for individual participant data (IPD) systematic reviews 2015. Aggregated data from the included studies were obtained and meta-analyzed regarding both the overall pAVF efficacy and the comparison of pAVF with surgical AVF (sAVF). We performed a two-stage IPD meta-analysis for studies comparing pAVF and sAVF regarding primary and secondary patency. Primary end points included primary patency, secondary patency, and functional cannulation.

RESULTS

Eighteen studies with 1863 patients were included. The overall pAVF, primary patency, secondary patency, functional cannulation and abandonment rates were 54.01% (95% confidence interval [CI], 40.69-66.79), 87.27% (95% CI, 81.53-91.42), 79.94% (95% CI, 65.94-89.13), and 15.58% (95% CI, 7.77-28.79), respectively. The overall pAVF, technical success, maturation, reintervention per person-years and mean time to maturation rates were 97.08% (95% CI, 95.66-98.04), 82.13% (95% CI, 71.64-89.32), 0.80 (95% CI, 0.34-1.47), and 58 days (95% CI, 36.64-92.82), respectively. Secondary patency and pAVF abandonment rates where the only end points were WavelinQ and Ellipsys displayed statistically significant differences of 81.36% (95% CI, 76.15-85.65) versus 92.12% (95% CI, 87.94-94.93) and 32.54% (95% CI, 22.23-44.87) versus 11.13% (95% CI, 4.82-23.65). An IPD meta-analysis of hazard ratios for primary and secondary patency between pAVF and sAVF were 1.27 (95% CI, 0.61-2.67) and 1.25 (95% CI, 0.87-1.80), favoring sAVF. Statistically significant difference between pAVF and sAVF were solely depicted for steal syndrome relative risk of 5.91 (95% CI, 1.12-31.12) and wound infections relative risk of 4.19 (95% CI, 1.04-16.88). Plotting of pAVF smoothed hazard estimate displayed an upsurge in the probability of primary patency failure at 1 month after the intervention.

CONCLUSIONS

Although we failed to identify statistically significant differences between pAVF and sAVF regarding any of the primary end points, pAVF displayed a decreased risk for steal syndrome and wound infection. Although both the Ellipsys and WavelinQ devices displayed satisfactory secondary patency rates, Ellipsys demonstrated a statistically significant improved rate compared with WavelinQ. Additionally, and despite the borderline statistically insignificant inferior reintervention rate displayed by WavelinQ, one in three WavelinQ pAVFs resulted in abandonment. The introduction of pAVF as a treatment modality calls for standardized definition adjustment and improvement.

Second Percutaneous Transluminal Angioplasty Versus Surgical Reconstruction for Hemodialysis Access Failure Within a Short Time Period

BACKGROUND

The purpose of this study was to compare patency and nonabandonment rates for second percutaneous transluminal angioplasty (PTA) and surgical reconstruction for the treatment of failing vascular access due to restenosis or reocclusion in a short time after initial PTA.

METHODS

Seventy two consecutive patients who underwent second treatment within 90 days after the initial PTA were evaluated retrospectively. The patency (time to corrective procedure) and access abandonment were compared among patients who underwent a second PTA (n = 35) and those who underwent surgical reconstruction (n = 37). Univariate and multivariate analyses were performed to determine independent predictors of patency and access abandonment at 1 year after the treatment.

RESULTS

At 1 year after the treatment, the patency rates were 35.1% and 11.4% (P = 0.02) and nonabandonment rates were 64.9% and 77.1% (P = 0.25) for surgical reconstruction and second PTA, respectively. The Kaplan-Meier survival analysis showed that the surgical reconstruction group had better patency probability (P = 0.02), but there was no difference in the nonabandonment probability between the groups (P = 0.29). Shorter time to retreatment was associated with good patency. The female gender was likely to be associated with access abandonment.

CONCLUSIONS

The access abandonment between the 2 procedures had no difference, although surgical reconstruction provided better patency than second PTA.

Temporal regulation of notch activation improves arteriovenous fistula maturation

BACKGROUND

Arteriovenous fistula (AVF) maturation is a process involving remodeling of venous arm of the AVFs. It is a challenge to balance adaptive AVF remodeling and neointima formation. In this study we temporally controlled Notch activation to promote AVF maturation while avoiding neointima formation.

METHODS

Temporal Notch activation was controlled by regulating the expression of Notch transcription factor, RBP-Jκ, or dnMAML1 (dominant negative MAML2) in vascular smooth muscle cells (VSMCs). AVF mouse model was created and VSMC phenotype dynamic changes during AVF remodeling were determined.

RESULTS

Activated Notch was found in the nuclei of neointimal VSMCs in AVFs from uremic mice. We found that the VSMCs near the anastomosis became dedifferentiated and activated after AVF creation. These dedifferentiated VSMCs regained smooth muscle contractile markers later during AVF remodeling. However, global or VSMC-specific KO of RBP-Jκ at early stage (before or 1 week after AVF surgery) blocked VSMC differentiation and neointima formation in AVFs. These un-matured AVFs showed less intact endothelium and increased infiltration of inflammatory cells. Consequently, the VSMC fate in the neointima was completely shut down, leading to an un-arterialized AVF. In contrast, KO of RBP-Jκ at late stage (3 weeks after AVF surgery), it could not block neointima formation and vascular stenosis. Inhibition of Notch activation at week 1 or 2, could maintain VSMC contractile markers expression and facilitate AVF maturation.

CONCLUSIONS

This work uncovers the molecular and cellular events in each segment of AVF remodeling and found that neither sustained increasing nor blocking of Notch signaling improves AVF maturation. It highlights a novel strategy to improve AVF patency: temporally controlled Notch activation can achieve a balance between adaptive AVF remodeling and neointima formation to improve AVF maturation.

TRANSLATIONAL PERSPECTIVE

Adaptive vascular remodeling is required for AVF maturation. The balance of wall thickening of the vein and neointima formation in AVF determines the fate of AVF function. Sustained activation of Notch signaling in VSMCs promotes neointima formation, while deficiency of Notch signaling at early stage during AVF remodeling prevents VSMC accumulation and differentiation from forming a functional AVFs. These responses also delay EC regeneration and impair EC barrier function with increased inflammation leading to failed vascular remodeling of AVFs. Thus, a strategy to temporal regulate Notch activation will improve AVF maturation.

Study protocol for Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID)

Background

A functioning vascular access (VA) is crucial to providing adequate hemodialysis (HD) and considered a critically important outcome by patients and healthcare professionals. A validated, patient-important outcome measure for VA function that can be easily measured in research and practice to harvest reliable and relevant evidence for informing patient-centered HD care is lacking. Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID) aims to assess the accuracy and feasibility of measuring a core outcome for VA function established by the international Standardized Outcomes in Nephrology (SONG) initiative.

Methods

VALID is a prospective, multi-center, multinational validation study that will assess the accuracy and feasibility of measuring VA function, defined as the need for interventions to enable and maintain the use of a VA for HD.

The primary objective is to determine whether VA function can be measured accurately by clinical staff as part of routine clinical practice (Assessor 1) compared to the reference standard of documented VA procedures collected by a VA expert (Assessor 2) during a 6-month follow-up period. Secondary outcomes include feasibility and acceptability of measuring VA function and the time to, rate of, and type of VA interventions.

An estimated 612 participants will be recruited from approximately 10 dialysis units of different size, type (home-, in-center and satellite), governance (private versus public), and location (rural versus urban) across Australia, Canada, Europe, and Malaysia.

Validity will be measured by the sensitivity and specificity of the data acquisition process. The sensitivity corresponds to the proportion of correctly identified interventions by Assessor 1, among the interventions identified by Assessor 2 (reference standard). The feasibility of measuring VA function will be assessed by the average data collection time, data completeness, feasibility questionnaires and semi-structured interviews on key feasibility aspects with the assessors.

Discussion

Accuracy, acceptability, and feasibility of measuring VA function as part of routine clinical practice are required to facilitate global implementation of this core outcome across all HD trials. Global use of a standardized, patient-centered outcome measure for VA function in HD research will enhance the consistency and relevance of trial evidence to guide patient-centered care.

Trial registration

Clinicaltrials.gov: NCT03969225. Registered on 31st May 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02987-1.

Differential hemodynamics between arteriovenous fistulas with or without intervention before successful use

A significant number of arteriovenous fistulas (AVFs) fail to maturate for dialysis. Although interventions promote maturation, functional primary patency loss is higher for AVFs with interventions (assisted maturation) than AVFs without interventions (un-assisted maturation). Although blood flow-associated hemodynamics have long been proposed to affect AVF remodeling, the optimal hemodynamic parameters for un-assisted maturation are unclear. Additionally, AVF maturation progress is generally not investigated until 6 weeks after AVF creation, and the examination is focused on the AVF's venous limb. In this exploratory study, patients (n = 6) underwent magnetic resonance imaging (MRI) at 1 day, 6 weeks, and 6 months after AVF creation surgery. Before successful use for hemodialysis, three AVFs required intervention and three did not. MRI of the AVFs were used to calculate lumen cross-sectional area (CSA) and perform computational fluid dynamics (CFD) to analyze hemodynamics, including velocity, wall shear stress (WSS), and vorticity. For the venous limb, the no-intervention group and intervention group had similar pre-surgery vein diameter and 1-day post-surgery venous CSA. However, the no-intervention group had statistically larger 1-day venous velocity (0.97 ± 0.67 m/s; mean ± SD), WSS (333 ± 336 dyne/cm2) and vorticity (1709 ± 1290 1/s) than the intervention group (velocity = 0.23 ± 0.10 m/s; WSS = 49 ± 40 dyne/cm2; vorticity = 493.1 ± 227 1/s) (P < 0.05). At 6 months, the no-intervention group had statistically larger venous CSA (43.5 ± 27.4 mm2) than the intervention group (15.1 ± 6.2 mm2) (P < 0.05). Regarding the arterial limb, no-intervention AVF arteries also had statistically larger 1-day velocity (1.17 ± 1.0 m/s), WSS (340 ± 423 dyne/cm2), vorticity (1787 ± 1694 1/s), and 6-month CSA (22.6 ± 22.7 mm2) than the intervention group (velocity = 0.64 ± 0.36 m/s; WSS = 104 ± 116 dyne/cm2, P < 0.05; vorticity = 867 ± 4551/s; CSA = 10.7 ± 6.0 mm2, P < 0.05). Larger venous velocity, WSS, and vorticity immediately after AVF creation surgery may be important for later lumen enlargement and AVF maturation, with the potential to be used as a tool to help diagnose poor AVF maturation earlier. However, future studies using a larger cohort are needed to validate this finding and determine cut off values, if any.

Upper limb exercise for arteriovenous fistula maturation in people requiring permanent haemodialysis access

BACKGROUND

The failure of arteriovenous fistulas (AVF) to mature is a major problem in patients with kidney failure who require haemodialysis (HD). Preoperative planning is an important factor in increasing functional AVF. Upper limb exercise has been recommended to gain AVF maturation. Studies of pre- and post-operative upper limb exercises in patients with kidney failure patients have been reported; however, the optimal program for this population is unknown due to inconsistent results among these programs.

OBJECTIVES

We aimed to determine if upper limb exercise would be beneficial for AVF maturation (prior to and post AVF creation) in patients with kidney failure and to improve AVF outcomes. This review also aimed to identify adverse events related to upper limb exercise.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 15 March 2022 through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov, and other resources (e.g. reference list, contacting relevant individuals, and grey literature).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs, comparing upper limb exercise training programs with no intervention or other control programs before or after AVF creation in patients with kidney failure. Outcome measures included time to mature, ultrasound and clinical maturation, venous diameter, blood flow in the inflow artery, dialysis efficacy indicator, vascular access function (functional AVF), vascular access complications, and adverse events.

DATA COLLECTION AND ANALYSIS

Study selection and data extraction were taken by four independent authors. Bias assessment and quality assessment were undertaken independently by two authors. The effect estimate was analysed using risk ratio (RR) with 95% confidence intervals (CI) for dichotomous data, or mean difference (MD) or standardised mean difference (SMD) for continuous data. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Nine studies (579 participants) were included, and seven studies (519 participants) conducting post-operative exercise training could be meta-analysed. Three comparisons were undertaken: (i) isotonic exercise training versus no intervention; (ii) isometric versus isotonic exercise training; and (iii) isotonic (high volume) versus isotonic exercise training (low volume). Due to insufficient data, we could not analyse pre-operative exercise training. Overall, the risk of bias was low for selection and reporting bias, high for performance and attrition bias, and unclear for detection bias. Compared to no intervention, isotonic exercise training may make little or no difference to ultrasound maturation (2 studies, 263 participants: RR 1.09, 95% CI 0.94 to 1.25; I² = 0%; low certainty evidence), but may improve clinical maturation (2 studies, 263 participants: RR 1.14, 95% CI 1.02 to 1.27; I² = 0%; low certainty evidence). Compared to isotonic exercise training, isometric exercise training may improve both ultrasound maturation (3 studies, 160 participants: RR 1.56, 95% CI 1.21 to 2.00; I² = 22%; low certainty evidence) and clinical maturation (3 studies, 160 participants: RR 1.80, 95% CI 1.18 to 2.76; I² = 53%; low certainty evidence). Venous diameter (3 studies, 160 participants: MD 0.84 mm, 95% CI 0.45 to 1.23; I² = 0%; low certainty evidence) and blood flow in the inflow artery (3 studies, 160 participants: MD 140.62 mL/min, 95% CI 38.72 to 242.52; I² = 0%; low certainty evidence) may be greater with isometric exercise training. It is uncertain whether isometric exercise training reduces vascular access complications (2 studies, 110 participants: RR 2.54, 95% CI 0.38 to 17.08; I² = 47%; very low certainty evidence). It is uncertain whether high volume isotonic exercise training improves venous diameter (2 studies, 93 participants: MD 0.19 mm, 95% CI -0.75 to 1.13; I² = 34%; very low certainty evidence) or blood flow in the inflow artery (1 study, 15 participants: MD -287.70 mL/min, 95% CI -625.99 to 60.59; very low certainty evidence) compared to low volume isotonic exercise training. None of the included studies reported time to mature, dialysis efficacy indicator, vascular access function, or adverse events.

AUTHORS' CONCLUSIONS

Our findings suggest that the current research evidence examining upper limb exercise programs is of low quality, attributable to variability in the type of interventions used and the overall low number of studies and participants.

Evaluation of the clinical utility of the PromarkerD in-vitro test in predicting diabetic kidney disease and rapid renal decline through a conjoint analysis

BACKGROUND

Early identification of patients at risk of developing diabetic kidney disease or rapid renal decline is imperative for appropriate patient management, but traditional methods of predicting renal decline are limited.

OBJECTIVE

This study evaluated the impact of PromarkerD, a biomarker-based blood test predicting the risk of diabetic kidney disease (DKD) and rapid renal decline.

METHODS

Conjoint analysis clarified the importance of PromarkerD and other patient attributes to physician decisions for type 2 diabetes patients. Forty-two patient profiles were generated, with varying levels of albuminuria, estimated glomerular filtration rate (eGFR), blood pressure, hemoglobin A1c (HbA1c), age, and PromarkerD result. A web-based survey asked each physician to make monitoring/treatment decisions about eight randomly selected profiles. Data were analyzed using multivariable logit models.

RESULTS

Two hundred three primary care physicians and 197 endocrinologists completed the survey. PromarkerD result was most important for increasing the frequency of risk factor monitoring. PromarkerD was second to HbA1c in importance for deciding to prescribe sodium/glucose cotransporter-2 inhibitors (SGLT2s) with a DKD indication, second to blood pressure for increasing the dose of lisinopril, and second to eGFR for replacing ibuprofen with a non-nephrotoxic medication. Compared with no PromarkerD results, a high-risk PromarkerD result was associated with significantly higher odds of increasing monitoring frequency (odds ratio [OR]: 2.56, 95% confidence interval: 1.90-3.45), prescribing SGLT2s (OR: 1.98 [1.56-2.52]), increasing lisinopril dose (OR: 1.48 [1.17-1.87]), and replacing ibuprofen (OR: 1.78 [1.32-2.40]). A low-risk PromarkerD result was associated with significantly lower odds of increasing monitoring frequency (OR: 0.48 [0.37-0.64]), prescribing SGLT2s (OR: 0.70 [0.56-0.88]), and replacing ibuprofen (OR: 0.75 [0.57-0.99]).

CONCLUSION

PromarkerD could increase adoption of renoprotective interventions in patients at high risk for renal decline and lower the likelihood of aggressive treatment in those at low risk. Further studies are needed to assess patient outcomes with PromarkerD in real-world practice.

A randomised control trial protocol of MuST for vascular access cannulation in hemodialysis patients (MuST Study): contributions for a safe nursing intervention

BACKGROUND

The vascular access preservation and the maintenance of a complication-free fistula remains an Achilles' heel of hemodialysis in chronic kidney patients due to its substantial contribution to the morbidity and mortality. Systematic studies in the area of examining cannulation practices, achieving complication-free cannulation, and strategies to improve fistula survival are needed. For this reason, we consider it essential to create and investigate new methodologies for approaching fistula in patients on regular HD. The Multiple Single Cannulation Technique (MuST) is based on the association between the rope-ladder (RL) using the arteriovenous vessel through progressive rotation, and the buttonhole (BH) since there are three specific cannulation sites for each cannulation day during the week. The MuST is simple to implement and seems to be a very promising technique in terms of patient safety. Previous studies already showed an arteriovenous fistula survival similar to RL but significantly higher than BH.

METHODS

This MuST study is a multicenter, prospective, non-blind, parallel-group, randomized controlled trial with the intervention group submitted to MuST and a control group undergoing the rope-ladder, up to 100 subjects for each group. Patients will be randomized 1:1 to one of two cannulation technique (CT), and the follow-up period of this study will be 12 months. Primary outcome is to evaluate the arteriovenous fistula survival rate at 12 months determined by the percentage of fistulas in use from the beginning of the study to the date of the first clinical intervention by angioplasty or vascular surgery, to maintain or restore patency (unassisted patency). Secondary outcome is to evaluate arteriovenous fistula survival rate at 12 month determined by the percentage of fistulas in use from the study start to the date of access abandonment due to dysfunction, patient abandonment, or death, treatment change modality or study end. We will also evaluate the assisted primary patency and include the following secondary outcomes associated with the cannulation technique: Infection, Hematoma, Aneurysm development, and pain.

DISCUSSION

The study will investigate whether fistula survival can be improved when using cannulation by MuST compared to the RL. MuST study will provide important information on fistula survival when cannulated by MuST but also information related to its use in fistulas previously cannulated by other CTs.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT05081648 registered on 18 October 2021.

Long Term Results from The Pivotal Multicenter Trial of Ultrasound Guided Percutaneous Arteriovenous Fistula Creation for Hemodialysis Access

PURPOSE

To report the five-year results from the Pivotal Multicenter Trial of Ultrasound Guided Percutaneous Arteriovenous Fistula (pAVF) Creation for Hemodialysis Access.

MATERIALS AND METHODS

Retrospective review of 107 intent-to-treat (ITT) patients from the pivotal trial provided a long-term follow-up population (LTP) of 85 patients followed a median 50 months (range 12-60). Data evaluated in the LTP group were fistula maturation and use, secondary procedures, and complications. Kaplan-Meier analysis of primary, primary assisted, cumulative patency, and functional patency (time from two-needle to abandonment) were performed for the ITT population.

RESULTS

In the LTP 99% (84/85) of fistulas were mature with 99% (78/79) of patients requiring hemodialysis using their pAVF. Sustained fistula use (two-needle cannulation at prescribed rate, 2/3 sessions) was achieved in 92% (78/85) of patients, with seven patients never using their pAVF because not on dialysis (n=4), peritoneal dialysis (n=2), and refusing to use fistula (n=1). Fistula maintenance was required in 31.8% (27/85) of patients and included fistula dysfunction (21.2%), thrombosis (5.9%), cannulation injury (12.9%), and arm swelling (4.7%). The number of procedures performed per patient per year (PPPY) to maintain function and patency was 0.32 (91/288) for years 2-5. The cumulative patency was 89.5%, 88.4%, 88.4%, 85.6%, and 82.0% years 1-5, respectively. The functional patency was 91.8% at the end of the study. There were no major complications related to pAVF during long-term follow-up CONCLUSION: Percutaneous fistulae have provided clinically effective and durable access for hemodialysis with low complications. Continued use and evaluation of pAVF is warranted.

Association of Permanent Vascular Access Dysfunction with Subsequent Risk of Cardiovascular Disease: A Population-Based Cohort Study

A functional permanent vascular access (VA) is required to perform a successful hemodialysis procedure. Hemodialysis VA dysfunction is a major cause of morbidity and hospitalization in the hemodialysis population. Cardiovascular disease (CVD) is the leading cause of death in patients receiving chronic hemodialysis. Information about CVD associated with hemodialysis VA dysfunction is unclear. We analyzed the association between dialysis VA dysfunction and the risk of developing CVD in hemodialysis patients. This nationwide population-based cohort study was conducted using data from the National Health Insurance Research Database in Taiwan. One million subjects were sampled from 23 million beneficiaries and data was collected from 2000 to 2013. Patients with end-stage renal disease who had received permanent VA construction and hemodialysis and were aged at least 20 years old from 2000 to 2007 were included in the study population. The primary outcome was CVD, as defined by ICD-9-CM codes 410–414 and 430–437. A total of 197 individuals with permanent VA dysfunction were selected as the test group, and 100 individuals with non-permanent VA dysfunction were selected as the control group. Compared with the control group, the adjusted hazard ratio of CVD for the VA dysfunction group was 3.05 (95% CI: 1.14–8.20). A Kaplan–Meier analysis revealed that the cumulative incidence of CVD was higher in the permanent VA dysfunction group than in the comparison group. Permanent VA dysfunction is significantly associated with an increased risk of subsequent CVD.

Preoperative Cardiac Index as a Predictor of Maturation and Primary Patency of Radiocephalic Arteriovenous Fistula in Hemodialysis

BACKGROUND

Radiocephalic arteriovenous fistula (RCAVF) is the best access modality to be considered initially when planning arteriovenous fistula (AVF) for maintenance hemodialysis. Considering the higher incidence of RCAVF failed maturation (M), it is important to perform proper preoperative evaluation and identification of high-risk patients. There has been no study on the influence of preoperative cardiac function on the M and patency of AVFs. The purpose of this investigation is to determine whether preoperative cardiac index (CI) is a predictor of M and primary patency of RCAVF.

METHOD

A total of 365 end-stage renal disease patients undergoing RCAVF surgery were consecutively enrolled with a median follow-up time of 20 months in this prospective cohort study. Demographics, vascular diameters measured by duplex ultrasound examination, and CI measured by echocardiography, were analyzed for effect on RCAVF primary functional M and primary patency.

RESULT

Patients in the group achieving primary RCAVF functional M had a significantly larger mean CI than the group with early RCAVF failure (2.93 ± 0.77 vs. 3.57 ± 0.76 L/min/m2, p < 0.001). The receiver operating characteristic curve was plotted and demonstrated that preoperative vein diameter and CI can predict failure of RCAVF M. The AUC of CI was higher (0.745 vs. 0.666). Multivariate regression analysis, adjusted for age, sex, diabetes, preoperative dialysis status and vessel diameters, showed that decreased CI remained associated with increased risk of failure of M (FM) and worse primary unassisted patency. The Kaplan-Meier survival analysis suggested that patients with CI <3 L/min/m2 had a worse primary unassisted patency rate at all time points compared with patients with CI ≥3 L/min/m2.

CONCLUSION

This study demonstrated that preoperative CI was associated with RCAVF M and long-term patency. A decreased CI may be a possible predictor of an increased risk of FM and a shorter primary patency time.

Evolutive profile of hemodialysis vascular accesses Hemodialysis accesses

INTRODUCTION

Arterio-venous fistula (AVF) is the first-choice vascular access for hemodialysis (HD). Hemodialysis catheter (KT) may be a temporary or permanent alternative.

AIM

To evaluate indications of KT and AVF and their predictive factors of complications.

METHODS

It's a retrospective multicentric study interesting KT and AVF in patients treated by hemodialysis, in the Kef Governorate in north-western Tunisia, during the period from 01/07/18 to 31/12/18.

RESULTS

We included 288 AVF and 148 KT that were created on 205 patients. The average age was 58.14 years, the sex ratio was 1.5. Hypertensive patients and diabetics represented respectively 83.9% and 27.3% of the population. Diabetic nephropathy was the most common (25.9%). For the KT, the main indication was the wait for AVF creation (68.9%). The overall incidence of immediate complications was 11.5%. Dysfunction was reported in 23.6% of cases with obesity and tunneled type of KT as contributing factors. KT infection was occuring in 39.2% of cases. It was promoted by prolonged duration of use and hemoglobin level < 8g/dl. The use of antiseptic lock reduced infections' risk (p=0.011). For AVF, the most common complications were thrombosis (36.2%), aneurysm (29.9%) and stenosis (22.6%). Survival rate was 60% at 2000 days. The AVF impairing factors were diabetes (p=0.05), obesity (p=0.05), anterior AVF creation (p=0.011), AVF grafts (p=0.016), and anticoagulant therapy (p=0.0001). Antiplatelet therapy improved AVF patency (p=0.02).

CONCLUSION

Much remained to be done to reduce KT complications, creation of AVF on time and prevention of their complications.

The association between the locations of arteriovenous fistulas and patency rates: A systematic review and meta-analysis

BACKGROUND

The arteriovenous fistulas (AVF) continue to be the most prevalent type of vascular access for hemodialysis (HD). However, the appropriate locations of AVF are controversial. We conducted the meta-analysis to investigate the differences in patency between upper-arm and forearm AVF.

METHODS

PubMed, EMBASE, CENTRAL, and ISI Web of Science were searched to identify studies with differences in AVF patency at different locations. Reviewers searched the database, screened studies according to inclusion criteria, and conducted Meta-analysis.

RESULTS

A total of 12 studies involving 3437 patients were selected. Pooled data showed that primary patency (PP) of AVF were higher in upper-arm than forearm at 1 and 2 years (odds ratio [OR] = 1.54, p = 0.0005; OR = 2.45, p = 0.001), but the differences in cumulative patency (CP) were not statistically significant at 1 and 2 years (OR = 2.10, p = 0.08; OR = 2.16, p = 0.1). The differences in PP and CP between upper-arm and forearm AVF in patients older than 65 years were not statistically significant at 1 (OR = 1.61, p = 0.05; OR = 2.05, p = 0.17) and 2 years (OR = 3.40, p = 0.13; OR = 1.38, p = 0.16). In Asian patients, the differences in PP and CP between upper-arm and forearm AVF were not statistically significant at 1 (OR = 1.17, p = 0.41; OR = 1.02, p = 0.94) and 2 years (OR = 2.95, p = 0.08; OR = 1.23, p = 0.41).

CONCLUSIONS

In this study, the CP of upper-arm and forearm AVF was similar in overall population. There was no difference in PP and CP of AVF between upper-arm and forearm in Asian population or the elderly. The forearm AVF could be consider to be the first choice. for Asian patients or the elderly.

Endovascular Arteriovenous Fistula Creation: A Review

Endovascular arteriovenous fistula (endoAVF) creation offers a minimally invasive method for the formation of arteriovenous shunts utilized for hemodialysis. Currently, there exist two similar yet unique devices: WavelinQ and Ellipsys. This review analyzes the anatomy, pre- and postoperative considerations, fistula creation methods, and outcomes associated with endoAVF. Currently, data are limited with regard to clinical efficacy of endoAVFs when compared to surgical AVFs. However, early data suggest endoAVFs are a useful technique in the creation of AVFs.

Pediatric hemodialysis access

Pediatric hemodialysis access is a demanding field. Procedures are infrequent, technically challenging, and associated with high complication and failure rates. Each procedure affects subsequent access and transplants sites. The choice is made easier and outcomes improved when access decisions are made by a multidisciplinary, pediatric, hemodialysis access team. This manuscript reviews the current literature and offers technical suggestions to improve outcomes.

Multiple single cannulation technique of arteriovenous fistula: A randomized controlled trial

Introduction

Despite the impact needling has had on vascular access survival and patient outcome, there is no universal or standardized method proposed for proper cannulation. Rigorous studies are needed, examining cannulation practices, and challenges to achieving complication‐free cannulation.

Methods

This randomized, open‐label trial was conducted at 18 dialysis units owned by a large private dialysis provider operating in Portugal. Eligible patients were adults on chronic hemodialysis, with a new arteriovenous fistula (AVF); cannulated for at least 4 weeks complication‐free. Patients were randomly assigned in a 1:1 ratio to one of three cannulation techniques (CT): Multiple Single cannulation Technique (MuST), rope‐ladder (RLC), and buttonhole (BHC). The primary endpoint was AVF primary patency at 1 year.

Findings

One hundred seventy‐two patients were enrolled between March 2014 and March 2017. Fifty‐nine patients were allocated to MuST, 56 to RLC, and 57 to BHC.

MuST and RLC were associated with a better AVF primary patency than BHC. Primary patency at 12 months was 76.3% in MuST, 59.6% in BHC, and 76.8% in RLC group. Mean AVF survival times were 10.5 months (95% CI = 9.6, 11.3) in the MuST group, 10.4 months (95% CI = 9.5, 11.2) in RLC, and 9.5 months (95% CI = 8.6, 10.4) in BHC. BHC was a significant risk predictor for AVF survival with 2.13 times more events than the other two CT (HR 2.13; 95% CI = 1.07, 4.21; p = 0.03).

Discussion

MuST was easy to implement without a diagram and there is no need to use blunt needles. This study showed MuST was efficacious and safe in maintaining the longevity of AVF in dialysis patients.

Transjugular intrahepatic portosystemic shunt creation may be associated with hyperplastic hepatic nodular lesions in the long term: an analysis of 18 pediatric and young adult patients

BACKGROUND

Retrospective studies have demonstrated the efficacy and safety of pediatric and adolescent transjugular intrahepatic portosystemic shunt (TIPS), but long-term outcomes warrant further investigation.

OBJECTIVE

To report on the development of hyperplastic hepatic nodular lesion development in children and young adults (<21 years) with TIPS patency >3 years.

MATERIALS AND METHODS

Eighteen children and young adults, including 10 (55.6%) females and 8 (44.4%) males, underwent TIPS creation with >3 years' patency and follow-up evaluation at a tertiary children's hospital. The mean age at the time of TIPS creation was 12.5±5.1 years (range: 1.5-20.0 years). The mean model for end-stage liver disease (MELD) at the time of TIPS creation was 8.1±1.6 (range: 6-11). Indications for TIPS creation included acute variceal bleeding (8/18, 44.4%), primary (1/18, 5.6%) or secondary (7/18, 38.9%) prevention of varices, portal vein thrombosis (1/18, 5.6%), and splenic sequestration (1/18, 5.6%). Technical successes, intra-procedural parameters, hemodynamic and clinical successes, TIPS patencies, adverse events, imaging evaluations, and follow-ups were recorded.

RESULTS

All (100%) TIPS placements were successful; however, a direct intrahepatic portosystemic shunt was created in one (5.6%) patient. Mean reduction of the portosystemic shunt gradient was 9.1±3.3 mmHg (range: 4-16 mmHg). Seventeen (94.4%) patients demonstrated clinical success with resolution of their initial clinical indication for TIPS placement. The 3-year TIPS primary, primary-assisted, and secondary patencies were 83.3% (15/18), 94.4% (17/18), and 100% (18/18), respectively. Two (11.1%) patients developed mild, medically controlled hepatic encephalopathy. One (5.6%) patient developed hepatopulmonary syndrome. Nine (50%) patients developed single or multiple hepatic nodules at a mean imaging surveillance time after TIPS of 4.4±3.0 years (range: 1.5-10.2 years). Six (33.3%) patients developed nodules >1 cm with imaging features most consistent with focal nodular hyperplasia or focal nodular hyperplasia-like nodules. The mean follow-up duration was 5.7±2.9 years (range: 3.0-13.1 years).

CONCLUSION

Long-term (>3 years) portosystemic shunting via TIPS is associated with the development of hepatic nodular lesions in children. Consequently, children with TIPS may need gray-scale assessment of hepatic parenchyma as part of routine ultrasound exams and extended imaging surveillance until more is understood regarding the natural history of induced nodularity.

Comparison of one-year patency rates of end-to-side and side-to-side anastomosis technique in proximal forearm region radial-cephalic fistulas

OBJECTIVES

In this study, the effects of anastomosis techniques on the results of patients with autogenous radial-cephalic proximal forearm fistula were investigated.

METHODS

Patients who underwent radial-cephalic proximal forearm fistula surgery (arteriovenous fistula) between April 2015 and August 2017 at the Department of Cardiovascular Surgery of Ordu University were compared retrospectively in terms of the results of anastomosis techniques. The study included 131 patients who had arteriovenous fistulas created by side-to-side and end-to-side anastomosis technique.

RESULTS

There was no significant difference in demographic data, comorbidities, radial artery, and cephalic vein diameters in patients undergoing radial-cephalic proximal forearm fistula surgery. However, it was observed that fistula maturation was earlier in the group with end-to-side anastomosis technique, and the one-year patency rates were higher in the group with side-to-side anastomosis technique.

CONCLUSION

In Arteriovenous fistulas created in the proximal forearm region, the one-year patency rate of the side-to-side anastomosis technique was higher, while the maturation of the end-to-side technique observed earlier.

Outcomes and predictors of failure of arteriovenous fistulae for hemodialysis

Purpose

Arteriovenous fistula(AVF) is preferred vascular access for hemodialysis but has primary failure in 20–60%. Studying predictors of AVF failure would help plan appropriate management.We studied AVF outcomes, clinical and vascular factors predicting their failure in patients requiring hemodialysis.

Methods

Retrospective study of patients with AVF creation from January 2017 to December 2018. Outcomes studied were immediate (< 72 h), primary (3 months) AVF failure, six-month/one-year patency, analyzed for predictive clinical, vascular factors as assessed using Pre-operative Doppler Ultrasound(DUS).

Results

Of 530 AVFs in 460 patients, DUS was done in 426/530 (80.4%), 349/460 (75.8%) were males, mean age was 53.10 ± 14.54 (18–91), 215/460(46.7%) had Diabetes mellitus(DM), 423/460(92%) hypertension. AVFs were radiocephalic in 79/530 (14.9%), brachiocephalic 418/530 (78.9%), brachiobasilic 33/530 (6.2%). AVF Immediate/Primary failure was seen in 64/530 (12.1%), 90/352 (25.6%); Patency at six months/one year in 253/352(71.8%),191/305 (62.6%), respectively. Older age had less immediate failures (AOR 0.97, CI 0.95–0.99, p 0.03). Feeding arterial diameter predicted immediate and primary failure on univariate analysis [OR 0.64 (95% CI 0.49–0.83), 0.62 (95% CI 0.47–0.89), respectively], but not multivariate. Artery diameter of > 4.0 mm had less failures [immediate (p 0.01), primary (p 0.02)], < 2.0 mm had specificity 95.9% and 95.4% for immediate, primary failure respectively.

Conclusion

AVF failure is 12.1%, immediately; 25.6% three months after construction, Patency at 6 months is 71.8%, one year 62.6%. Immediate failures decrease with age. Artery diameters > 4.0 mm had less, < 2.0 mm had more failures.