Comparison of Clinical Effectiveness and Safety of Drug-Coated Balloons versus Percutaneous Transluminal Angioplasty in Arteriovenous Fistulae: A Review of Systematic Reviews and Updated Meta-Analysis

PURPOSE

To evaluate the clinical effectiveness and safety of drug-coated balloons (DCBs) compared with those of percutaneous transluminal angioplasty (PTA) for arteriovenous fistula (AVF) stenosis via a review of systematic reviews (SRs) and an update of the current meta-analysis.

MATERIALS AND METHODS

Literature was searched to retrieve SRs comparing DCBs and PTA for AVFs. A narrative review of SRs and pooled analysis were performed.

RESULTS

Eleven SRs were included. DCBs demonstrated favorable outcomes at 6 and 12 months compared with PTA, with improved patency in 7 SRs and a trend toward favorable outcomes without statistical significance in 3 SRs. Target lesion revascularization (TLR) was reported in 3 SRs; 2 reviews reported a significantly lower incidence in the DCB group than in the PTA group, whereas 1 review reported no significant differences at 12 months. Four studies reporting all-cause mortality revealed no significant difference between the 2 treatments. In the updated meta-analysis including 23 studies, DCBs demonstrated improved primary patency at 6 months (risk ratio [RR], 1.27; 95% CI, 1.07-1.50) and 12 months (RR, 1.36; 95% CI, 1.19-1.55) and were associated with a lower incidence of TLR at 6 months (RR, 0.54; 95% CI, 0.41-0.73) and 12 months (RR, 0.78; 95% CI, 0.62-0.99). There was no difference in mortality between the 2 groups for 24 months.

CONCLUSIONS

A review of SRs and meta-analysis update revealed the consistent benefits of DCBs over PTA in treating AVFs in terms of primary patency and TLR. Compared with PTA, DCBs do not increase mortality risk.

Use of a Paclitaxel Drug-Eluting Stent for the Treatment of Hemodialysis Access Outflow Stenosis

PURPOSE

To evaluate the outcomes and durability of drug-eluting stents (DESs) for the treatment of hemodialysis access outflow stenosis.

MATERIAL AND METHODS

A single-center retrospective analysis was conducted of all patients with hemodialysis vascular access outflow stenosis treated with a paclitaxel-coated DES (Eluvia; Boston Scientific, Marlborough, Massachusetts) between January 2020 and July 2022. A total of 34 DESs were implanted to treat outflow stenosis in 32 patients. Primary target lesion patency after stent deployment was the main outcome. Comparison between the time interval free from target lesion reintervention (TLR) after previous plain balloon angioplasty (PBA) and that after stent deployment for the same target lesion was considered a secondary outcome.

RESULTS

The primary patency at 6, 12, and 18 months was 63.1%, 47.6%, and 41.7%, respectively. The secondary patency rate was 100% at 18 months. The median time interval free from TLR increased from 4.1 to 11.9 months (P < .001). No adverse events were observed during the median follow-up period of 387 days.

CONCLUSIONS

The patency rates after use of DES for hemodialysis access outflow stenosis were comparable with results for drug-coated balloons and stent grafts, addressing recoil and minimizing the risk of jailing by a covered stent.

Study protocol for a Prospective, Randomized controlled trial of stEnt graft and Drug-coated bAlloon Treatment for cephalic arch stenOsis in dysfunctional arteRio-venous fistulas (PREDATOR)

BACKGROUND

Treatment of cephalic arch stenosis (CAS) is associated with high risk of failure and complications. Although stent-graft (SG) placement has improved patency rates, stent edge restenosis has been raised as a potential limiting factor for SG usage in CAS. This study aims to evaluate the safety and efficacy of combining stent graft placement with paclitaxel-coated balloon (PCB) angioplasty versus PCB alone in the treatment of CAS.

METHODS

This is an investigator-initiated, prospective, international, multicenter, open-label, randomized control clinical trial that plans to recruit 80 patients, who require fistuloplasty from dysfunctional arteriovenous fistula (AVF) from CAS. Eligible participants are randomly assigned to receive treatment with SG and PCB or PCB alone in a 1:1 ratio post-angioplasty (n = 40 in each arm). Randomization is stratified by de novo or recurrent lesion, and the participants are followed up for 1 year. The primary endpoints of the study are target lesion primary patency (TLPP) and access circuit primary patency (ACPP) rates at 6-months. The secondary endpoints are TLPP and ACPP at 3- and 12-month; target lesion and access circuit assisted primary and secondary patency rates at 3, 6, and 12-months and the total number of interventions; complication rate; and cost-effectiveness.

DISCUSSION

This study will evaluate the clinical efficacy and safety of combination SG and PCB implantation compared to PCB alone in the treatment of CAS for hemodialysis patients.

Sirolimus-coated balloon angioplasty in maintaining the patency of thrombosed arteriovenous graft: 1-year results of a prospective study

BACKGROUND

A prospective, pilot study was designed to test the feasibility of using sirolimus-coated balloon (SCB) to treat graft vein junction of thrombosed arteriovenous graft (AVG) following successful pharmacomechanical thrombectomy. The present report provides the 1-year results of this study.

METHODS

This is a 1-year follow-up of a single, prospective, single-arm study that was conducted from 2018 to 2019 in 20 patients who presented to a tertiary institution with thrombosed AVG. The recruited patients received SCB angioplasty at the graft-vein junction following successful endovascular thrombectomy of a thrombosed AVG. One year after recruitment, there were three deaths, one AVG revision, and one AVG explantation among the participants recruited. The outcomes of 15 subjects at 1-year following the index procedure obtained from electronic medical records were re-examined.

RESULTS

The 1-year access circuit primary patency rate was 40%, while assisted primary and secondary patency rates were 46.7% and 73.3%, respectively. A total of 16 interventions (4 angioplasties, 12 thrombectomies) were performed in 9 patients over the 12 months. Four AVGs were abandoned. The median number of interventions per patient was 1 (0-3) per year. Using Kaplan-Meier analysis, the mean estimated post-intervention access circuit primary patency was 230 (95% CI: 162-300) days, while access circuit assisted primary patency was 253 (95% CI: 187-320) days, and access circuit secondary patency was 292 (95% CI: 230-356) days. Sub-group analysis did not show a significant difference in the mean estimated primary patency between AVG with de novo and recurrent stenosis (245 days, 95% CI: 151-339 vs 210 days, 95% CI: 113-307; p = 0.29).

CONCLUSIONS

SCB may help sustain the patency of thrombosed AVG following successful thrombectomy.

Dialysis Access Maintenance: Plain Balloon Angioplasty

Plain balloon angioplasty remains the first-line treatment for dialysis access stenosis. This chapter reviews the outcomes of plain balloon angioplasty from cohort studies and comparative studies. Angioplasty outcomes are more favourable in arteriovenous fistulae (AVF) compared to arteriovenous grafts (AVG) with primary patency at 6 months ranging from 42-63% compared to 27-61%, respectively, and improved for forearm fistulae compared with upper arm fistulae. Higher pressures are required to treat stenoses in AVFs compared to AVGs. Outcomes are worse in more severe stenoses, increased patient age, previous interventions and fistulae that develop early stenoses. Major complication rates following angioplasty in dialysis access are between 3 and 5%. Repeat treatments and the use of adjuncts such as drug-coated balloons and stents can prolong the patency of dialysis access. Level of Evidence No level of evidence (Review paper).

Long-term mortality and patency after drug-coated balloon angioplasty in the hemodialysis circuit: A systematic review and meta-analysis of randomized controlled trials

PURPOSE

To compare all-cause mortality and primary patency with drug-coated balloon angioplasty (DCBA) compared with plain balloon angioplasty (PBA) in people with hemodialysis-related stenosis.

MATERIALS AND METHODS

PubMed, Embase, and Cochrane Library databases were searched from November 1966 to February 2021 to identify randomized controlled trials (RCTs) that assessed the use of DCBA versus PBA for stenosis in hemodialysis circuits. Data extracted from the articles were integrated to determine all-cause mortality, target lesion primary patency (TLPP), circuit access primary patency (CAPP), 30-day adverse events, and technical success for the two approaches. We performed meta-analysis on these results using a fixed-effects model to evaluate odds ratios (ORs) and 95% confidence intervals (CIs) where I2 < 50% in a test for heterogeneity, or a random-effect model if otherwise. Sensitivity and subgroup analyses were also performed.

RESULTS

Sixteen RCTs of 1672 individuals were included in our meta-analysis, of which 839 individuals received DCBA and 833 received PBA. The pooled outcome showed no statistical difference between DCBA and PBA in all-cause mortality at 6 months (OR = 1.29, 95% CI = 0.72-2.32, p = 0.39, I2 = 4%), 12 months (OR = 1.02, 95% CI = 0.68-1.53, p = 0.91, I2 = 0%), and 24 months (OR = 1.50, 95% CI = 0.87-2.57, p = 0.15, I2 = 0%), 30-day adverse events (OR = 1.09, 95% CI = 0.30-3.98, p = 0.90, I2 = 66%), and technical success (OR = 0.18, 95% CI = 0.02-1.92, p = 0.16, I2 = 65%). The DCBA had significantly better outcomes versus PBA in TLPP at 6 months (OR = 2.37, 95% CI = 1.84-3.04, p < 0.001, I2 = 44%) and 12 months (OR = 1.77, 95% CI = 1.22-2.56, p = 0.002, I2 = 56%), and CAPP at 6 months (OR = 2.07, 95% CI = 1.21-3.54, p = 0.008, I2 = 67%) and 12 months (OR = 1.66, 95% CI = 1.29-2.15, p < 0.001, I2 = 0%).

CONCLUSION

In hemodialysis circuit stenosis, DCBA appears to have similar safety but greater efficacy than PBA.

Comparison of drug-coated balloon angioplasty versus common balloon angioplasty for arteriovenous fistula stenosis: A systematic review and meta-analysis

Drug-coated balloons (DCBs) have been used in dialysis patients with arteriovenous fistula (AVF) stenosis, but whether DCBs have advantages over ordinary balloons is still controversial. A meta-analysis was designed to investigate the safety and efficacy of DCBs and common balloons (CBs) in the treatment of AVF stenosis. We searched the PubMed, EMBASE, and China National Knowledge Internet (CNKI) databases for randomized controlled trials that evaluated the comparison of DCB angioplasty versus CB angioplasty for AVF stenosis in dialysis patients and reported at least one outcome of interest. The results showed that the DCB group had a higher first-stage patency rate of the target lesion 6 months [odds ratio, OR = 2.31, 95% confidence interval, CI: (1.69, 3.15), p < .01] and 12 months [OR = 2.09, 95% CI: (1.50, 2.91), p < .01] after surgery. There was no statistically significant difference in all-cause mortality between the two groups at 6 months [OR = 0.85, 95% CI: (0.47, 1.52), p = .58] and 12 months [OR = 0.99, 95% CI: (0.60, 1.64), p = .97]. Compared with CB, DCBs as a new endovascular treatment for AVF stenosis have a higher primary patency rate of target lesions and can delay the occurrence of restenosis. There is no evidence that DCB can increase the mortality of patients.

Drug-eluting balloon (DEB) versus plain old balloon angioplasty (POBA) in the treatment of failing dialysis access: A prospective randomized trial

Objective

To compare the efficacy of angioplasty using drug-eluting balloons (DEB) compared with plain old balloon angioplasty (POBA) to reduce the rate of restenosis.

Methods

This prospective, single-centre, single-blinded, 1:1 randomized, clinical trial enrolled patients that had primary or restenotic lesions in native upper extremity arteriovenous (AV) fistulas or at the graft-venous anastomosis. Patients were randomized to angioplasty with a POBA or a DEB. The primary effectiveness endpoints were freedom from target lesion revascularization (TLR) and functional status of access circuit at 12 months.

Results

A total of 42 (28 male, 14 female; age range, 42–83 years) patients were enrolled. Patients were followed for 12 months. No significant differences were detected between the POBA and DEB groups regarding total number of TLR procedures (31 versus 36, respectively), freedom from TLR (3 versus 4, respectively) and functional status of the access circuit at 12 months (14 of 20 patients [70%] versus 17 of 22 patients [77%], respectively).

Conclusion

This clinical trial did not demonstrate any significant differences between DEB angioplasty and standard balloon angioplasty when treating dysfunctional haemodialysis access.

Drug-Coated Balloons for the Dysfunctional Vascular Access: An Evidence-Based Road Map to Treatment and the Existing Obstacles

An underlying stenosis within the venous limb of a hemodialysis access circuit is the main etiology for graft and fistula dysfunction as well as other symptoms such as arm, breast, and neck swelling. Treatment options for both peripheral and central venous stenoses include plain old balloon angioplasty, angioplasty with drug-coated balloons, and stenting. This article discusses the current evidence for the use of drug-coated balloon angioplasty in this patient population.

Paclitaxel coated balloon versus conventional balloon angioplasty in dysfunctional dialysis arteriovenous fistula: a systematic review and meta-analysis of randomized controlled trials

Purpose

To compare the efficacy and safety between paclitaxel coated balloon (PCB) angioplasty and conventional balloon (CB) angioplasty in the treatment of dysfunctional arteriovenous fistula (AVF).

Methods

We searched four major electronic databases (PubMed, EMBASE, Web of Science and the Cochrane Library) for randomized controlled trials (RCTs) published from inception through November 28, 2021. Outcomes of interest included target lesion primary patency (TLPP), technical success and all-cause mortality. The STATA package version 15.1 was utilized to undertake meta-analyses.

Results

Fourteen RCTs totaling 1535 patients were analyzed. The available data showed that there were no significant differences of TLPP rates at 3, 6, 9 and 12 months between the PCB group and the CB group (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.93–1.07, p = 1.000, I² = 33.5%, Cochrane Q test p = 0.185, fixed-effect model; RR 1.17, 95% CI 0.99–1.39, p = 0.065, I² = 75.4%, Cochrane Q test p = 0.000, random-effect model; RR 0.81, 95% CI 0.35–1.89, p = 0.625, I² = 62.8%, Cochrane Q test p = 0.045, random-effect model; RR 1.19, 95% CI 0.97–1.47, p = 0.096, I² = 40.5%, Cochrane Q test p = 0.071, random-effect model). In addition, two groups had similar technical success rates (RR 1.00, 95% CI 0.97–1.03, p = 1.000, I² = 0.0%, Cochrane Q test p = 0.596, fixed-effect model) and all-cause mortality rates (RR 1.00, 95% CI 0.54–1.84, p = 1.000, I² = 0.0%, Cochrane Q test p = 0.599, fixed-effect model).

Conclusions

PCB angioplasty did not appear to convey any obvious advantage over CB angioplasty in the treatment of dysfunctional AVF. However, further multi-center, large-scale and well-designed RCTs are needed to prove outcomes.

SIroliMus coated angioPlasty versus plain balloon angioplasty in the tREatment of dialySis acceSs dysfunctION (IMPRESSION): study protocol for a randomized controlled trial

Background

Percutaneous transluminal angioplasty is the current standard treatment for arteriovenous fistula (AVF) stenosis. The mid- and long-term patency with plain balloon angioplasty (PBA) is however far from satisfactory. While paclitaxel-coated balloon angioplasty has been shown to be superior to PBA, concern over its safety profile has recently arisen after a reported possible increased mortality risk with a meta-analysis of large lower limb studies. An angioplasty balloon with a new type of drug coating, the sirolimus-coated balloon (SCB), has been proven to improve patency in the coronary arteries. However, its effect on AV access has yet to be studied.

Methods/design

This is an investigator-initiated, prospective, multicenter, double-blinded, randomized controlled clinical trial to assess the effectiveness of SCB compared to PBA in improving the patency of AVF after angioplasty. A total of 170 patients with mature AVF that requires PTA due to AVF dysfunction will be randomly assigned to treatment with a SCB or PBA at a 1:1 ratio, stratified by location of AVF and followed up for up to 1 year. The inclusion criteria include [1] adult patient aged 21 to 85 years who requires balloon angioplasty for dysfunctional arteriovenous fistula [2]; matured AVF, defined as being in use for at least 1 month prior to the angioplasty; and [3] successful angioplasty of the underlying stenosis with PBA, defined as less than 30% residual stenosis on digital subtraction angiography (DSA) and restoration of thrill in the AVF on clinical examination. The exclusion criteria include thrombosed or partially thrombosed access circuit at the time of treatment, presence of symptomatic or angiographically significant central vein stenosis that requires treatment with more than 30% residual stenosis post angioplasty, and existing stent placement within the AVF circuit. The primary endpoint of the study is access circuit primary patency at 6 months. The secondary endpoints are target lesion primary patency; access circuit-assisted primary patency; access circuit secondary patency at 3, 6, and 12 months; target lesion restenosis rate at 6 months; total number of interventions; complication rate; and cost-effectiveness. The trial is supported by Concept Medical.

Discussion

This study will evaluate the clinical efficacy and safety of SCB compared to PBA in the treatment of AVF stenosis in hemodialysis patients.

Trial registration

ClinicalTrials.govNCT04409912. Registered on 1 June 2020

Drug-Coated Balloon Versus Plain Balloon Angioplasty for Hemodialysis Dysfunction: A Meta-Analysis of Randomized Controlled Trials

Background Both drug-coated balloon (DCB) angioplasty and conventional plain balloon angioplasty (PBA) can be implemented to treat hemodialysis dysfunction. The present study aims to compare the safety and efficacy of these 2 approaches by conducting a meta-analysis of available randomized controlled trials. Methods and Results PubMed, Cochrane Library, and Embase databases were queried from establishment to January 2021. A total of 18 randomized controlled trials including 877 and 875 patients in the DCB and PBA groups, respectively, were included in the present meta-analysis. Target lesion primary patency, circuit patency, target lesion revascularization, and mortality were pooled. Odds ratios (ORs) were reported with 95% CIs. Publication bias was analyzed with funnel plot and Egger test. Target lesion primary patency was higher among patients who underwent DCB (OR, 2.93 [95% CI, 2.13-4.03], P<0.001 at 6 months; OR, 2.47 [95% CI, 1.53-3.99], P<0.001 at 1 year). Also, the DCB group had a higher dialysis circuit patency at 6 months (OR, 2.42; 95% CI, 1.56-3.77 [P<0.001]) and 1 year (OR, 1.91; 95% CI, 1.22-3.00 [P=0.005]). Compared with the PBA group, the DCB group had lower odds of target lesion revascularization during follow-up (OR, 0.43 [95% CI, 0.23-0.82], P=0.001 at 6 months; OR, 0.74 [95% CI, 0.32-1.73], P=0.490 at 1 year). The OR of mortality was comparable between 2 groups at 6 months (OR, 1.18; 95% CI, 0.42-3.33 [P=0.760]) and 1 year (OR, 0.93; 95% CI, 0.58-1.48 [P=0.750]). Conclusions Based on evidence from 18 randomized controlled trials, DCB angioplasty is superior to PBA in maintaining target lesion primary patency and circuit patency among patients with dialysis circuit stenosis. DCB angioplasty also reduces target lesion revascularization with a similar risk of mortality compared with PBA.

Treatment of cephalic arch stenosis in dysfunctional arteriovenous fistulas with paclitaxel-coated versus conventional balloon angioplasty

Background

Treatment of cephalic arch stenosis (CAS) with standard plain old balloon angioplasty (POBA) in dysfunctional arteriovenous fistulas (AVF), is associated with early re-stenosis and higher failure rates compared to other lesions. Paclitaxel-coated balloons (PCB) may improve patency rates. This is a retrospective cohort study. Patients who underwent POBA or PCB for CAS over a 3-year period were included. Outcomes compared were circuit primary patency rates (patency from index procedure to next intervention), circuit primary assisted-patency rates (patency from index procedure to thrombosis), and target lesion (CAS) patency rates (stenosis > 50%) at 3, 6 and 12 months.

Results

Ninety-one patients were included. Sixty-five (71.4%) had POBA, while 26 (28.6%) had PCB angioplasty. There were 62 (68.1%) de-novo lesions. CAS was the only lesion that needed treatment in 24 (26.4%) patients. Circuit primary patency rates for POBA versus PCB groups were 76.2% vs. 60% (p = 0.21), 43.5% vs. 36% (p = 0.69) and 22% vs. 9.1% (p = 0.22) at 3, 6 and 12-months respectively. Circuit assisted-primary patency rates were 93.7% vs. 92% (p = 1.00), 87.1% vs. 80% (p = 0.51) and 76.3% vs. 81.8% (p = 0.77), whilst CAS target lesion intervention-free patency rates were 79.4% vs. 68% (p = 0.40), 51.6% vs. 52% (p = 1.00) and 33.9% vs. 22.7% (p = 0.49) at 3, 6 and 12-months respectively. Estimated mean time to target lesion intervention was 215 ± 183.2 days for POBA and 225 ± 186.6 days for PCB (p = 0.20).

Conclusion

Treatment of CAS with PCB did not improve target lesion or circuit patency rates compared to POBA.

Drug-coated balloon angioplasty for failing haemodialysis access: meta-analysis of randomized clinical trials

BACKGROUND

Arteriovenous fistulas, a major treatment for end-stage kidney disease, frequently require endovascular reinterventions to maintain haemodialysis function. Drug-coated angioplasty balloons (DCBs) were developed with the intention of reducing reintervention rates. The aim of this study was to perform a systematic review and meta-analysis of DCBs in the treatment of failing haemodialysis access.

METHODS

Electronic databases were searched systematically to identify all relevant RCTs and any follow-up studies from RCTs. Pooled estimates of dichotomous outcomes were calculated using the odds ratio (OR) and 95 per cent confidence interval. Effect data are presented as summary hazard ratio and 95 per cent confidence interval.

RESULTS

Some 19 studies from 18 RCTs and comprising 1898 patients were included in the meta-analysis. Compared with plain balloon angioplasty (PBA), DCB use was associated with higher target-lesion primary patency (HR 0.60, 95 per cent c.i. 0.45 to 0.79), access-circuit primary patency (HR 0.67, 0.56 to 0.80), and less target-lesion revascularization (TLR) within 6 months (OR 0.33, 0.23 to 0.47). No difference was observed between DCB and PBA in 12-month TLR (OR 0.62, 0.28 to 1.37). Mortality after DCB use was similar to that associated with PBA use at 6 months (OR 1.20, 0.65 to 2.21) and 12 months (OR 0.99, 0.66 to 1.49), and was higher at 24 months (23.1 versus 16.6 per cent), although the difference was not statistically significant (OR 1.53, 0.92 to 2.53).

CONCLUSION

Drug-coated balloon angioplasty of haemodialysis fistulas is associated with higher patency rates and lower rates of reintervention in the short to mid term. Although mortality rates appeared to be higher with drug-coated angioplasty at 24 months, this did not reach statistical significance.

Editor's Choice - Paclitaxel Coated Balloon Angioplasty vs. Plain Balloon Angioplasty for Haemodialysis Arteriovenous Access Stenosis: A Systematic Review and a Time to Event Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

A systematic review and meta-analysis of randomised controlled trials (RCTs) was performed to determine the effectiveness and safety of drug coated balloon (DCB) angioplasty compared with uncoated plain balloon (PB) angioplasty in treating arteriovenous access stenosis.

METHODS

MEDLINE, Embase, Scopus, and the Cochrane Central Register of Controlled Trials were searched for RCTs comparing paclitaxel coated DCB and PB angioplasty for arteriovenous access stenosis. The last date of the literature search was 31 December 2020. Risk of bias of the retrieved studies was assessed with the Cochrane Collaboration tool for assessing risk of bias (RoB 2.0). The random effects model was used to estimate the risk of loss of target lesion patency (six and 12 months) and circuit patency (six and 12 months). Procedure related adverse events and mortality rate were also compared. Patency results were pooled using the time to event meta-analytical method and the quality of evidence was assessed according to the GRADE approach.

RESULTS

Sixteen eligible trials, including 1 682 lesions, were included in the quantitative analysis for the efficacy and safety of paclitaxel coated DCBs. DCBs were associated with a lower risk of loss of target lesion patency at six months (HR 0.53, 95% CI 0.42 - 0.66) and 12 months (HR 0.60, 95% CI 0.47 - 0.76), and were also associated with improved six and 12 month circuit patency. Overall quality of evidence was moderate to low. Procedural complications were rare, and the risk of death up to 12 months was similar between the two groups (OR 1.03, 95% CI 0.68 - 1.56).

CONCLUSION

Paclitaxel coated DCBs reduced the risk of loss of target lesion patency and circuit patency in arteriovenous access stenosis compared with PBs. Considering the heterogeneity of the included trials, there is a need to investigate optimal treatment regimens regarding drug dose and agent of the DCB and the treatment procedure.

Drug Coated Balloons for Dysfunctional Haemodialysis Venous Access: A Patient Level Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

To perform an individual patient data level meta-analysis of randomised controlled trials comparing drug coated balloon angioplasty (DCB) against conventional percutaneous transluminal angioplasty (PTA) in the treatment of dysfunctional haemodialysis venous access.

METHODS

A search was conducted from inception to 13 November 2020. Kaplan-Meier curves comparing DCB with PTA by target lesion primary patency (TLPP) and access circuit primary patency (ACPP) were graphically reconstructed to retrieve patient level data. One stage meta-analyses with Cox models with random effects shared frailties were conducted to determine hazard ratios (HRs). Dynamic restricted mean survival times (RMST) were conducted in view of violation of the proportional hazards assumption. Conventional two stage meta-analyses and network meta-analyses under random effects Frequentist models were conducted to determine overall and comparative outcomes of paclitaxel concentrations used. Where outliers were consistently detected through outlier and influence analyses, sensitivity analyses excluding those studies were conducted.

RESULTS

Among 10 RCTs (1 207 patients), HRs across all models favoured DCB (one stage shared frailty HR 0.62, 95% CI 0.53 - 0.73, p < .001; two stage random effects HR 0.60, 95% CI 0.42 - 0.86, p = .018, I² = 65%) for TLPP. Evidence of time varying effects (p = .005) was found. TLPP RMST was + 3.54 months (25.0%) longer in DCB treated patients compared with PTA (p = .001) at three years. TLPP at six months, one year, and two years was 75.3% vs. 58.1%, 51.1% vs. 37.1%, and 31.4% vs. 26.0% for DCB and PTA, respectively. The P-Scores within the Frequentist network meta-analysis suggest that higher concentrations of paclitaxel were associated with better TLPP and ACPP. Among six RCTs (854 patients), the one stage model favoured DCB (shared frailty HR 0.72, 95% CI 0.60 - 0.87, p < .001) for ACPP. Conversely, the two stage random effects model demonstrated no significant difference (HR 0.76, 95% CI 0.35 - 1.67, p = .41, I² = 81%). Sensitivity analysis excluding outliers significantly favoured DCB (HR 0.61, 95% CI 0.41 - 0.91, p = .027, I² = 62%).

CONCLUSION

Overall evidence suggests that DCB is favoured over PTA in TLPP and ACPP.

A multicenter randomized controlled trial indicates that paclitaxel-coated balloons provide no benefit for arteriovenous fistulas

The role of paclitaxel-coated balloons has been established in the coronary and peripheral arterial circulations with recent interest in the use of paclitaxel-coated balloons to improve patency rates following angioplasty of arteriovenous fistulas. To assess the efficacy of paclitaxel-coated angioplasty balloons to prolong the survival time of target lesion primary patency in arteriovenous fistulas, we designed an investigator-led multi-center randomized controlled trial with follow up time variable for a minimum of one year. Patients with an arteriovenous fistula who were undergoing an angioplasty for a clinical indication were included but patients with one or more lesions outside the treatment segment were excluded. Following successful treatment with a high-pressure balloon, 212 patients were randomized. In the intervention arm, the second component was insertion of a paclitaxel-coated balloon. In the control arm, an identical procedure was followed, but using a standard balloon. The primary endpoint was time to loss of clinically driven target lesion primary patency. Primary analysis showed no significant evidence for a difference in time to end of target lesion primary patency between groups: hazard ratio 1.18 with a 95% confidence interval of 0.78 to 1.79. There were no significant differences for any secondary outcomes, including patency outcomes and adverse events. Thus, our study demonstrated no evidence that paclitaxel-coated balloons provide benefit, following standard care high-pressure balloon angioplasty, in the treatment of arteriovenous fistulas. Hence, in view of the benefit suggested by other trials, the role of paclitaxel-coated angioplasty balloons remains uncertain.

Intimal Hyperplasia and Arteriovenous Fistula Failure: Looking Beyond Size Differences

The development of venous intimal hyperplasia (IH) has been historically associated with failure of arteriovenous fistulas (AVF) used for hemodialysis. This long-standing assumption, based on histological observations, has been recently challenged by clinical studies indicating that the size of the intima by itself is not enough to explain stenosis or AVF maturation failure. Irrespective of this lack of association, IH is present in most native veins and fistulas, is prominent in many cases, and suggests a role in the vein that may not be reflected by its dimensions. Therefore, the contribution of IH to AVF dysfunction remains controversial. Using only clinical data and avoiding extrapolations from animal models, we critically discuss the biological significance of IH in vein remodeling, vascular access function, and the response of the venous wall to repeated trauma in hemodialysis patients. We address questions and pose new ones such as: What are the factors that contribute to IH in pre-access veins and AVFs? Do cellular phenotypes and composition of the intima influence AVF function? Are there protective roles of the venous intima? This review explores these possibilities, with hopes of rekindling a critical discussion about venous IH that goes beyond thickness and AVF outcomes.

Paclitaxel-Coated Balloons for the Treatment of Symptomatic Central Venous Stenosis in Vascular Access: Results From a European, Multicenter, Single-Arm Retrospective Analysis

INTRODUCTION

This was a European, multicenter, investigator-initiated and run, single-arm retrospective analysis to assess the safety and the clinical benefit of the use of paclitaxel-coated balloon (PCB) for the treatment of symptomatic central venous stenosis (CVS).

MATERIALS AND METHODS

Eleven centers from 7 countries across Europe, submitted 86 cases performed during the period between October 2015 and June 2018. Minimum follow-up was 6 months. Patient baseline demographics and procedural details were collected. Mean age was 62.6 years (SD 15.2 years). Median vascular access age was 3.0 years (IQR 1.2-4.8 years). A total of 55 were arteriovenous fistulas (64%) the rest arteriovenous grafts (31/86, 36%). Vessels treated were 43 subclavian veins, 42 brachiocephalic veins and 1 superior vena cava. Median drug-coated balloon diameter was 10 mm (IQR 8-12 mm). Primary outcome measures were clinically assessed intervention-free period (IFP) of the treated segment at 6 months and procedure-related minor and major complications. Secondary outcome measures included access circuit survival, patient survival, and the investigation of independent factors that influence the IFP.

RESULTS

IFP was 62.7% at 6 months. Median patient follow-up time was 1.0 year (IQR 0.5-2.2 years). There was 1 minor complication (1/86; 1.2%) and no major complications. Access circuit survival was 87.7% at 6 months. Patient survival was 79.7% at 2 years according to Kaplan-Meier survival analysis. Higher balloon diameters significantly favored IFP [HR 0.71 (0.55-0.92), p=0.006; 5-7 mm group vs 8-12 mm group, p=0.025].

CONCLUSION

In this analysis, use of PCBs for the treatment of symptomatic CVS was safe. Efficacy was comparable to previous trials. Increased balloon size had a significant effect on patency rates.

Plain versus paclitaxel-coated balloon angioplasty in arteriovenous fistula and graft stenosis: An umbrella review

An umbrella review was performed to synthesize the evidence from systematic reviews/meta-analyses of clinical trials investigating the efficacy and safety of paclitaxel-coated balloons (PCB) vs. conventional balloon angioplasty in arteriovenous fistulas (AVFs) and grafts stenosis.Medline (via PubMed) and SCOPUS databases were searched up to July 15th 2020. All meta-analyses that enrolled randomized controlled trials (RCTs) comparing PCB with plain balloons in AVFs and grafts were included. Re-analysis of original data was performed assessing predictive intervals (PI). Quality of the included meta-analyses was assessed using AMSTAR score. Eight meta-analyses were included and four clinical outcomes [target lesion primary patency (TLPP), circuit primary patency, mortality, complication rate] derived from 14 RCTs, were analyzed. There were no significant differences in the TLPP in meta-analyses providing data purely from autologous AVFs. Significant benefits regarding TLPP and circuit primary patency at 3, 6, and 12-months in favor of PCB were reported in four meta-analyses mixing AVFs and grafts; however when PI were assessed, in all but one meta-analysis these included the null value, indicating no significant benefit. In only one meta-analysis significant difference of TLPP at 12-months in favor of PCB was noticed. (Odds Ratio 0.0009 PI: 0.28-0.85) No mortality difference was noticed in four meta-analyses providing data up to 24 months. In conclusion this overview revealed a modest benefit of using PCB angioplasty compared to plain angioplasty in AVFs and graft stenosis. No increased mortality was noticed in the PCB group.

A Multicenter Global Registry of Paclitaxel Drug-Coated Balloon in Dysfunctional Arteriovenous Fistulae and Grafts: 6-Month Results

PURPOSE

To assess the safety and clinical benefit of the Lutonix drug-coated balloon (DCB) catheter for the treatment of dysfunctional arteriovenous fistulae (AVF) and grafts (AVG) in a heterogenous real-world population.

MATERIALS AND METHODS

This multicenter, prospective study enrolled 320 subjects from 12 countries in 25 sites across Europe and Asia. A total of 392 lesions were treated with the Lutonix 035 DCB catheter. Lesions were de novo and restenotic, located in every part of the circuit from the cannulation zone to central venous outflow. In-stent restenotic lesions also were treated. The primary safety endpoint was freedom from serious adverse events involving the access circuit through 30 days. The primary effectiveness endpoint was target lesion primary patency (TLPP) through 6 months. Secondary endpoints included access circuit primary patency (ACPP) at 6 months and the investigation of factors that would independently influence the primary endpoints.

RESULTS

The primary safety endpoint was 95.5%, while TLPP was 73.9% at 6 months, per Kaplan-Meier survival analysis. ACPP was 71% at 6 months. TLPP for stenosis of AVFs was 78.1%. Subgroup analysis showed significantly improved TLPP when DCB was dilated for ≥120 seconds (P = .007). TLPP was significantly better when predilation occurred compared with cases where only DCB angioplasty was performed (77% vs 48.6%, P = .0005).

CONCLUSIONS

The Lutonix AV Global Registry confirms that the Lutonix DCB is a safe and effective treatment option in real-world patients with dysfunctional AVF or AVG. Procedural details had a significant role in TLPP. No significant difference in TLPP was observed among different treatment areas.

Safety and Efficacy of Paclitaxel-Eluting Balloon Angioplasty for Dysfunctional Hemodialysis Access: A randomized trial Comparing with Angioplasty Alone

PURPOSE

To assess whether angioplasty of hemodialysis access (HA) stenosis with a drug-coated balloon (DCB) would prevent restenosis in comparison with plain-balloon percutaneous transluminal angioplasty (PTA).

MATERIALS AND METHODS

This prospective randomized clinical trial enrolled 120 patients with dysfunctional arteriovenous fistulae (n = 109) and grafts (n = 11), due to a ≥50% stenosis between March 2014 and April 2018. All patients underwent high-pressure balloon angioplasty and were then randomized to either DCB (n = 60) or PTA (n = 60). Patients were followed-up for 1 year, and angiography was performed 6 months after angioplasty. The primary endpoint was the late lumen loss (LLL) at 6 months. Secondary endpoints included other angiographic parameters at 6 months and HA failures, adverse event, and mortality at 12 months. Continuous variables were compared with a Student t-test, and Kaplan-Meier curves were used for freedom from HA failure and for mortality.

RESULTS

LLL in the DCB and in the PTA group were 0.64 mm ± 1.20 and 1.13 mm ± 1.51, respectively (P = .082, adjusted P = .0498). DCB was associated with lower percentage stenosis (54.2% ± 19.3 vs 61.7% ± 18.2; P = .047) and binary restenosis ≥50% (56.5% vs 81.1%; P = .009) than PTA. The number of HA failures after 12 months was lower for DCB than for PTA (45% vs 66.7%; P = .017). Mortality at 12 months was 10% and 8.3% in the DCB and PTA groups, respectively (P = .75).

CONCLUSIONS

Despite LLL improvement that failed to reach statistical significance, this study demonstrated decreased incidence and severity of restenosis with DCB compared with PTA to treat dysfunctional HA.

Network meta-analysis of trials comparing first line endovascular treatments for arteriovenous fistula stenosis

OBJECTIVE

We investigated the comparative effectiveness of different endovascular treatments for patients with failing autogenous arteriovenous fistulas (AVFs) with outflow vein stenosis.

METHODS

The Medline (via PubMed) and SCOPUS databases were searched. We performed a systematic review and network meta-analysis of randomized controlled trials that had investigated the effectiveness of plain balloon angioplasty (PBA), cutting balloon angioplasty, and drug-coated balloon angioplasty (DCBA) to treat vein stenoses in autogenous AVFs. Studies of central vein stenosis were excluded. The main outcome measures were the failure rates at 6 months and 1 year after treatment.

RESULTS

Eleven randomized controlled trials were included, with 814 patients, 395 of whom had undergone PBA. The network meta-analysis showed that DCBA at 6 months was significantly more effective than PBA (odds ratio, 0.39; 95% confidence interval, 0.18-0.81) and ranked as the best treatment option, although the difference was not statistically significant compared with cutting balloon angioplasty (odds ratio, 0.65; 95% confidence interval, 0.20-2.12). The differences among the three treatments at 1 year were not statistically significant. Additional conventional pairwise meta-analyses did not find significant differences at 1 year.

CONCLUSIONS

In failing AVFs with outflow stenosis, DCBA was significantly superior to PBA, with improved 6-month failure rates. However the effectiveness of DCBA in the long term deserves further investigation.

Single-Center Prospective Pilot Study of Sirolimus Drug-Coated Balloon Angioplasty in Maintaining the Patency of Thrombosed Arteriovenous Graft

PURPOSE

To investigate the use of a sirolimus drug-coated balloon (DCB) in the management of a thrombosed arteriovenous graft (AVG).

MATERIALS AND METHODS

A single-center prospective pilot study was conducted between October 2018 and October 2019. Twenty patients (age = 67.0 years ± 10; male = 35%; mean time on dialysis = 31 months) with thrombosed upper limb AVG were enrolled. After successful pharmacomechanical thrombectomy and adequate treatment of the graft vein junction, sirolimus DCB angioplasty was performed at the graft vein junction. The patients were followed-up for 6 months, and all adverse events occurring during the study period were recorded.

RESULTS

The primary circuit patency rates at 3 and 6 months were 76% and 65%, respectively, while the assisted-primary circuit patency rates at 3 and 6 months were 82% and 65%, respectively. The 3- and 6-month secondary circuit patency rates were 88% and 76%, respectively. Using Kaplan-Meier analyses, the estimated mean primary, assisted-primary, and secondary patencies were 285 days (95% confidence interval (CI) = 194-376 days), 319 days (95% CI = 221-416 days), and 409 days (95% CI = 333-485 days). No adverse event directly related to sirolimus DCB use was observed.

CONCLUSIONS

The results of this pilot study suggest that the application of sirolimus DCB at the graft vein junction after the successful thrombectomy of AVG may be a feasible option to improve patency outcomes.

Randomized Controlled Trial for Paclitaxel-coated Balloon versus Plain Balloon Angioplasty in Dysfunctional Hemodialysis Vascular Access: 12-month Outcome from a Nonsponsored Trial

BACKGROUND

Plain balloon angioplasty is regarded as the mainstay of treatment for failing vascular access with high success rate, but the poor treatment durability creates significant workload and increases patient morbidity. The study aims to compare target lesion primary patency rate at 12 months between paclitaxel-coated balloon (DCB) versus plain old balloon angioplasty (POBA) for treatment of dysfunctional vascular access.

METHODS

This nonsponsored-randomized trial enrolled 40 patients with dysfunctional dialysis access at a single center. Patients were randomized into In.Pact Admiral Paclitaxel DCB or POBA after lesion crossing regardless of lesion type. Patients are followed up under surveillance protocol. Patients, hemodialysis staff, and sonographer are blinded to the treatment arms. Twelve-month primary patency rate in both arms are evaluated.

RESULTS

40 patients were recruited since June 2016 and were allocated to the DCB or POBA group. The mean age is 58 and 57 years with comparable demographic parameters. The locations of target lesion were comparable in both groups (juxta and arteriovenous anastomosis, cannulation site, and fistula/graft), with similar mean target lesion stenosis 69.8 +/- 15.8% for DCB and 69.5 +/- 13.6% for POBA (P = 0.95), and the lesion length for DCB is 45.8 +/- 38.4 mm and 50.2 +/- 33.5 mm for POBA (P = 0.70). Patients in DCB performed significantly better in terms of primary patency at 6 months 85% versus 55% (P = 0.007). The superiority in primary patency in DCB group exists at 12 months 65% versus 30% (P = 0.007).

CONCLUSIONS

Paclitaxel balloon angioplasty approach provides significant better primary patency in dysfunctional arteriovenous access at 12 months in our nonsponsored-randomized trial.

Paclitaxel-Coated Balloon versus Plain Balloon Angioplasty for Dysfunctional Autogenous Radiocephalic Arteriovenous Fistulas: A Prospective Randomized Controlled Trial

Objective

To report the mid-term results of a single-center randomized controlled trial comparing drug-coated balloon angioplasty (DBA) and plain balloon angioplasty (PBA) for the treatment of dysfunctional radiocephalic arteriovenous fistulas (RCAVFs).

Materials and Methods

In this prospective study, 39 patients (mean age, 62.2 years; 21 males, 18 females) with RCAVFs failing due to juxta-anastomotic stenosis were randomly assigned to undergo either both DBA and PBA (n = 20, DBA group) or PBA alone (n = 19, PBA group) between June 2016 and June 2018. Primary endpoints were technical and clinical success and target lesion primary patency (TLPP); secondary outcomes were target lesion secondary patency (TLSP) and complication rates. Statistical analysis was performed using the Kaplan-Meier product limit estimator.

Results

Demographic data and baseline clinical characteristics were comparable between the groups. Technical and clinical success rates were 100% in both groups. There was no significant difference between the groups in the mean duration of TLPP (DBA group: 26.7 ± 3.6 months; PBA group: 27.0 ± 3.8 months; p = 0.902) and TLSP (DBA group: 37.3 ± 2.6 months; PBA group: 40.4 ± 1.5 months; p = 0.585). No procedural or post-procedural complications were identified.

Conclusion

Paclitaxel-coated balloon use did not significantly improve TLPP or TLSP in the treatment of juxta-anastomotic stenosis of dysfunctional RCAVFs.

Study protocol of a pilot study on sirolimus-coated balloon angioplasty in salvaging clotted arteriovenous graft

Background

In arteriovenous graft (AVG) for haemodialysis, the primary cause of failure is venous stenosis of the graft-vein junction from neointimal hyperplasia (NIH), resulting in thrombosis. While interventions to salvage clotted AVG are known to have high clinical success rates, long-term patency rates have been suboptimal. Drug-coated balloon (DCB) has been used to treat stenosed arteriovenous access in recent years with encouraging results but data on its effect in clotted AVG is unavailable.

Methods

This is an investigator-initiated, single-center, single-arm prospective pilot study to determine the safety and outcome of the sirolimus-coated balloon (SCB) in the salvage of thrombosed AVG. Twenty patients who undergo successful percutaneous thrombectomy will receive treatment with SCB at the graft vein junction. The patients will be followed-up for 6-months. The primary endpoint is the patency rates at 3-month while the secondary endpoints are the patency rates and the number of interventions needed to maintain patency at 6-month.

Discussion

Unremitting efforts have been made to prolong the patency of AV accesses over the years. DCB angioplasty combines mechanical and biological treatment for vascular stenosis. Sirolimus, being a cystostatic anti-proliferative agent, has been successfully used in coronary artery interventions. As the primary pathology of vascular stenosis in the dialysis circuit is neointimal hyperplasia, the use of sirolimus in balloon angioplasty may be effective. With this prospective study, we evaluate the efficacy and safety of SCB in patients with clotted AVG.

Trial registration

ClinicalTrials.gov Identifier: NCT03666208 on 11 September 2018.

A systematic review and meta-analysis of the risk of death and patency after application of paclitaxel-coated balloons in the hemodialysis access

OBJECTIVE

The comparison between paclitaxel-coated balloon (PCB) angioplasty and plain balloon angioplasty (PBA) for hemodialysis (HD) access stenosis or occlusion has not been well investigated. The objectives of this systematic review and meta-analysis were to compare all-cause mortality, HD access primary patency, and circuit primary patency after endovascular maintenance procedures using PCB angioplasty vs PBA.

METHODS

MEDLINE, Embase, and Cochrane Databases were systematically searched to identify all the relevant studies on paclitaxel-coated devices for stenosis or thrombosis of HD access. A random effects model was applied to pool the effect measures. Dichotomous data were presented using an odds ratio (OR). Effect data were presented using pooled hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

A total of 16 studies were included in this meta-analysis, 12 randomized controlled trials and 4 cohort studies involving 1086 patients who underwent endovascular treatment for HD access stenosis or occlusion. All-cause mortality rates at 6, 12, and 24 months after intervention were similar between the PCB and PBA groups (6 months: OR, 1.06 [95% CI, 0.38-2.96; P = .907; I² = 19.2%]; 12 months: OR, 1.20 [95% CI, 0.66-2.16; P = .554; I² = 0%]; 24 months: OR, 1.43 [95% CI, 0.83-2.45; P = .195; I² = 0%]). There was a significant improvement of primary patency in the PCB group compared with the PBA group (HR, 0.47; 95% CI, 0.33-0.69; P < .001; I² = 67.3%). This benefit was consistent with the analysis of randomized controlled trials, whereas cohort studies were excluded. Further subgroup analysis of target lesions demonstrated that primary patency was significantly higher in the PCB group than in the PBA group, not only for arteriovenous fistula (HR, 0.54; 95% CI, 0.30-0.98; P = .041; I² = 76.8%) but also for central venous stenosis (HR, 0.39; 95% CI, 0.22-0.71; P = .002; I² = 0%). The PCB group was associated with higher 6-month (OR, 0.40; 95% CI, 0.27-0.59; P < .001) and 24-month lesion primary patency (OR, 0.28; 95% CI, 0.11-0.72; P = .009) than PBA and was marginally associated with 12-month lesion primary patency (OR, 0.52; 95% CI, 0.26-1.03; P = .06). Circuit primary patency analysis showed a marginal trend toward better outcome in the PCB group (HR, 0.63; 95% CI, 0.40-1.00) but no statistical significance (P = .052).

CONCLUSIONS

This systematic review and meta-analysis demonstrated that PCB angioplasty is associated with significantly improved primary patency of arteriovenous fistula and central venous stenosis for HD access maintenance, with no evidence of increasing all-cause mortality based on short-term and midterm follow-up. Further large cohort study is needed to investigate long-term mortality.

Arteriovenous access in hemodialysis: A multidisciplinary perspective for future solutions

In hemodialysis, vascular access is a key issue. The preferred access is an arteriovenous fistula on the non-dominant lower arm. If the natural vessels are insufficient for such access, the insertion of a synthetic vascular graft between artery and vein is an option to construct an arteriovenous shunt for punctures. In emergency situations and especially in elderly with narrow and atherosclerotic vessels, a cuffed double-lumen catheter is placed in a larger vein for chronic use. The latter option constitutes a greater risk for infections while arteriovenous fistula and arteriovenous shunt can fail due to stenosis, thrombosis, or infections. This review will recapitulate the vast and interdisciplinary scenario that characterizes hemodialysis vascular access creation and function, since adequate access management must be based on knowledge of the state of the art and on future perspectives. We also discuss recent developments to improve arteriovenous fistula creation and patency, the blood compatibility of arteriovenous shunt, needs to avoid infections, and potential development of tissue engineering applications in hemodialysis vascular access. The ultimate goal is to spread more knowledge in a critical area of medicine that is importantly affecting medical costs of renal replacement therapies and patients’ quality of life.

Drug-coated balloon versus conventional balloon angioplasty of hemodialysis arteriovenous fistula or graft: A systematic review and meta-analysis of randomized controlled trials

Background

Restenosis remains a significant problem in endovascular therapy for hemodialysis vascular access. Drug-coated balloon (DCB) angioplasty decreases restenosis in peripheral and coronary artery diseases. The aim of this systematic review and meta-analysis is to assess the patency outcomes following DCB angioplasty, as compared to conventional balloon (CB) angioplasty for the stenosis of hemodialysis vascular access.

Methods

A comprehensive search in the MEDLINE, EMBASE, and CENTRAL databases was conducted in order to identify eligible randomized controlled trials evaluating DCB angioplasty for hemodialysis vascular access dysfunction. The primary endpoint was the 6-month target lesion primary patency and the secondary endpoints were 12-month target lesion primary patency and procedure-related complications. Risk ratios (RR) were pooled and relevant subgroups were analyzed separately.

Results

Eleven randomized controlled trials comprised of 487 patients treated with DCB angioplasty and 489 patients treated with CB angioplasty were included. There were no significant differences in the target lesion primary patency at 6 months [RR, 0.75; 95% confidence interval (CI), 0.56, 1.01; p = 0.06] and at 12 months (RR 0.89; 95% CI, 0.79, 1.00; p = 0.06). The absence of benefit for the DCB group remained, even in the arteriovenous fistula subgroup or the subgroup of studies excluding central vein stenosis. The risk of procedure-related complication did not differ between the two groups (RR 1.00; 95% CI 0.98, 1.02; p = 0.95).

Conclusion

DCB angioplasty did not demonstrate significant patency benefit for the treatment of hemodialysis vascular access dysfunction. Wide variations in patency outcomes across studies were noted. Further studies focusing on specific types of access or lesions are warranted to clarify the value of DCB for hemodialysis vascular access. (PROSPERO Number CRD42019119938)

Comparative Effectiveness of Drug-Coated Balloon vs Balloon Angioplasty for the Treatment of Arteriovenous Fistula Stenosis: A Meta-analysis

Purpose: To compare the effectiveness and safety outcomes of drug-coated balloon angioplasty (DCBA) vs conventional balloon angioplasty (BA) for arteriovenous fistula (AVF) stenosis. Materials and Methods: A systematic review was conducted of PubMed and Embase databases from 1966 to May 2019 to identify English-language articles evaluating DCBA vs BA for the treatment of AVF stenosis. Data extracted from each study were synthesized to evaluate target lesion revascularization (TLR), technical success, and mortality for the 2 approaches. Meta-analyses were performed on these outcomes using random effects models to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup and sensitivity analyses were performed. Results: Twelve studies [6 randomized controlled trials (RCTs) and 6 cohort studies] comprising 979 patients were included in this meta-analysis. The pooled results showed that AVFs treated with DCBA had significantly fewer TLRs at 6 months (OR 0.31, 95% CI 0.14 to 0.69, p=0.004) and 12 months (OR 0.45, 95% CI 0.21 to 0.97, p=0.04) than BA. The 2 approaches had similar technical success rates (OR 0.22, 95% CI 0.03 to 1.43, p=0.11). Additionally, the pooled OR of 12-month mortality was 0.71 (95% CI 0.20 to 2.51, p=0.60), indicating no significant difference between DCBA and BA. Subgroup analysis based on study design showed the superiority of DCBA to BA in cohort studies but not RCTs, which had high heterogeneity. Significant publication bias was found in the cohort studies. Conclusion: In de novo or recurrent AVF stenosis, DCBA appears to be an effective procedure associated with lower 6- and 12-month TLR compared with BA. However, larger and randomized controlled studies are warranted to draw definitive conclusions.

Use of Paclitaxel Eluting Stents in Arteriovenous Fistulas: A Pilot Study

Purpose

We report short-term patency outcomes of a proof of concept study conducted to determine the efficacy of drug-eluting stent (DES) for the treatment of arteriovenous fistula (AVF) stenosis in hemodialysis patients.

Materials and Methods

This is a single-center, retrospective observational study involving 10 patients with AVF dysfunction treated with DESs between January 2017 and December 2017. The primary outcome was AVF patency confirmed by sonographic and clinical assessment at 1 month and 6 to 9 months after treatment.

Results

A total of 12 DESs were deployed in 10 patients with dysfunctional AVF (radiocephalic: 7, brachiocephalic: 3). During the early follow up (mean: 28.6 days), primary access circuit and DES patency was 100%, with an average volume flow rate of 886.4 mL/min. Nine patients were available for short-term follow up (mean: 202.4 days; 1 unrelated death), with a mean volume flow rate of 1,048.9 mL/min. The primary DES patency was 7/9 (77.8%), and 3 patients required angioplasty at other parts of the circuit (primary access circuit patency: 4/9 [44.4%]). The assisted primary access circuit patency was 77.8%. In 2 patients, the ultrasound revealed that the DESs were thrombosed without any antecedent stenosis; they were salvaged with angioplasty. Both patients previously underwent 2 DESs implanted and recently stopped dual antiplatelet therapy. B-mode sonographic assessment at all timepoints showed minimal intimal ingrowth on the stent struts.

Conclusion

This study demonstrates acceptable short-term patency for DESs in the treatment of AVF stenosis. Dual antiplatelet therapy is probably mandatory in the short term.

Mortality After Paclitaxel-Coated Device Use in Dialysis Access: A Systematic Review and Meta-Analysis

Purpose: To report the risk of all-cause mortality in patients who underwent dialysis access treatment using paclitaxel-coated devices compared with percutaneous transluminal angioplasty (PTA) with an uncoated balloon. Materials and Methods: A systematic review and meta-analysis of randomized controlled trials were performed to investigate the mortality outcomes associated with paclitaxel-coated devices in the treatment of patients with a failing dialysis access (last search date February 28, 2019). The primary endpoint was all-cause mortality. This analysis included 8 studies comparing paclitaxel-coated balloon (PCB) angioplasty (n=327) and PTA (n=331) in the treatment of failing dialysis access. None investigated paclitaxel-coated stents. Mortality data were pooled using a random effects model. Statistical heterogeneity was evaluated with a chi-square test and the I2 statistic. Summary statistics are expressed as relative risk ratios (RR) with a 95% confidence interval (CI). Results: At the pooled mean follow-up of 13.5 months (median 12, range 6–24) all-cause mortality was similar in the PCB group (13.8%) compared with PTA (11.2%; RR 1.26, 95% CI 0.85 to 1.89, p=0.25; I2=0%). Subgroup analysis, stratified according to length of follow-up, confirmed that there were no statistically significant differences in mortality at short- and midterm follow-up [6-month (8 studies): 5.2% vs 4.8%, RR 1.24, 95% CI 0.62 to 2.47, p=0.55; 12-month (6 studies): 6.3% vs 6.0%, RR 1.06, 95% CI 0.43 to 2.63, p=0.90; and 24-month (3 studies): 19.0% vs 13.5%, RR 1.38, 95% CI 0.90 to 2.12, p=0.14). Conclusion: The analysis found no difference in short- to midterm mortality among patients treated with a drug-coated balloon compared with PTA. With proven benefit and no evidence of harm, the authors recommend ongoing use of PCB for the failing dialysis access.