Systematic Review of Drug Eluting Balloon Angioplasty for Arteriovenous Haemodialysis access Stenosis

Polymer-coated paclitaxel-eluting stents for the treatment of stenosed native arteriovenous fistulas: Long-term results from the ELUDIA study

BACKGROUND

Percutaneous transluminal angioplasty is the preferred treatment of stenosed failing arteriovenous fistulas (AVF) but is hampered by increasing rates of vascular restenosis because of development of myointimal hyperplasia.

METHODS

This multicenter observational study of polymer-coated low-dose paclitaxel-eluting stents (ELUvia stents by Boston Scientific) in stenosed AVF undergoing hemoDIAlysis (ELUDIA) was jointly conducted in three tertiary hospitals from Greece and Singapore. Failure of AVF was defined according to K-DOQI criteria and significant fistula stenosis (>50%DS by visual estimate) was determined with subtraction angiography. Patients were considered for ELUVIA stent insertion based on significant elastic recoil following balloon angioplasty for the treatment of a single vascular stenosis within a native AVF. The primary outcome measure was sustained long-term patency of the treated lesion/fistula circuit defined as successful stent placement with resumption of uninterrupted hemodialysis and without significant vascular restenosis (50%DS threshold) or other secondary interventions during follow-up.

RESULTS

Some 23 patients received the ELUVIA paclitaxel-eluting stent (eight radiocephalic, 12 brachiocephalic, and three transposed brachiobasilic native AVFs). Mean AVF age at the time of failure was 33.9 ± 20.4 months. Treated lesions included 12 stenoses at the juxta-anastomotic segment, nine at the outflow veins, and two cephalic arch lesions with a mean diameter stenosis of 86 ± 8%. Median stent diameter and length used were 7 mm and 40 mm, respectively. After a median follow-up period of 20 months, some 18 stents out of 23 cases remained patent (cumulative rate 78.3%) without any clinical or imaging evidence of recurrent stenosis. Estimated primary patency of the ELUVIA stents was 80.6% and of the corresponding fistula circuit 65.1% at 2 years by Kaplan-Meier methods.

CONCLUSIONS

This observational study has shown promising long-term results of polymer-coated paclitaxel-eluting stents for the treatment of failing arteriovenous fistulas. Large-scale controlled studies are necessary.

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.

Arteriovenous Access for Hemodialysis: A Review

Importance

Hemodialysis requires reliable vascular access to the patient's blood circulation, such as an arteriovenous access in the form of an autogenous arteriovenous fistula or nonautogenous arteriovenous graft. This Review addresses key issues associated with the construction and maintenance of hemodialysis arteriovenous access.

Observations

All patients with kidney failure should have an individualized strategy (known as Patient Life-Plan, Access Needs, or PLAN) for kidney replacement therapy and dialysis access, including contingency plans for access failure. Patients should be referred for hemodialysis access when their estimated glomerular filtration rate progressively decreases to 15 to 20 mL/min, or when their peritoneal dialysis, kidney transplant, or current vascular access is failing. Patients with chronic kidney disease should limit or avoid vascular procedures that may complicate future arteriovenous access, such as antecubital venipuncture or peripheral insertion of central catheters. Autogenous arteriovenous fistulas require 3 to 6 months to mature, whereas standard arteriovenous grafts can be used 2 to 4 weeks after being established, and "early-cannulation" grafts can be used within 24 to 72 hours of creation. The prime pathologic lesion of flow-related complications of arteriovenous access is intimal hyperplasia within the arteriovenous access that can lead to stenosis, maturation failure (33%-62% at 6 months), or poor patency (60%-63% at 2 years) and suboptimal dialysis. Nonflow complications such as access-related hand ischemia ("steal syndrome"; 1%-8% of patients) and arteriovenous access infection require timely identification and treatment. An arteriovenous access at high risk of hemorrhaging is a surgical emergency.

Conclusions and Relevance

The selection, creation, and maintenance of arteriovenous access for hemodialysis vascular access is critical for patients with kidney failure. Generalist clinicians play an important role in protecting current and future arteriovenous access; identifying arteriovenous access complications such as infection, steal syndrome, and high-output cardiac failure; and making timely referrals to facilitate arteriovenous access creation and treatment of arteriovenous access complications.

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.

USE of IMplanting the Biotronik PassEo-18 Lux drug coated balloon to treat failing haemodialysis arteRiovenous FIstulas and grafts (SEMPER FI Study)

BACKGROUND

Plain old balloon angioplasty has been the mainstay of treatment for arteriovenous fistula (AVF) stenoses. Recent studies suggest that drug coated balloons (DCB) may significantly reduce re-intervention rates on native and recurrent lesions. The Passeo-18 Lux DCB (Biotronik AG, Buelach, Switzerland) is packaged with a 3.0 µg/mm2 dose of paclitaxel. The hypothesis is that its use provides better target lesion primary patency (TLPP), primary assisted patency (PP), secondary patency (SP) rates and reduces the number of visits for re-intervention in a cohort of patients with stenotic AVF and arteriovenous grafts (AVGs).

METHODS

The USE of IMplanting the Biotronik PassEo-18 Lux DCB to treat failing haemodialysis arteRiovenous FIstulas and grafts trial (SEMPER FI) was a prospective double-centre, multi-investigator, non-consecutive, non-blinded single-arm study investigating the efficacy and safety of the Passeo-18 Lux DCB in patients with stenotic AVF/AVG lesions between January 2021 and January 2022. Patient demographics, clinical characteristics, vascular access history, operative indications, details and outcomes were collected prospectively. TLPP, circuit access primary patency (CAP), PP, SP and deaths 6- and 12-months post-intervention were studied.

RESULTS

Ninety-one patients with 110 lesions were recruited across the two centres. 62.6% (n = 57) were male with a median age of 63.5 years (SD = 10.5). 62.6% (n = 57) were taking anti-platelets. Eighty-five AVFs and six AVGs were treated. 60% (n = 54) of AVFs intervened were radiocephalic. 52.7% (n = 58) of targeted lesions were juxta-anastomotic stenosis (JAS) and one-third (n = 33) at the AVF/AVG outflow. 70.9% (n = 78) of lesions were recurrent. Median time from last intervention was 219 days. 78% of target lesions (n = 85) and circuits (n = 70) were patent at 6-months, of which 96.7% (n = 87) of those requiring assisted intervention were patent.

CONCLUSION

This study shows that the Passeo-18 Lux DCB can be an effective and safe tool in the treatment of failing haemodialysis AVFs/AVGs.

Transradial intervention in dialysis patients undergoing percutaneous coronary intervention: a Japanese nationwide registry study

Aims

Transradial intervention (TRI) for percutaneous coronary intervention (PCI) is used to reduce periprocedural complications. However, its effectiveness and safety for patients on dialysis are not well established. We aimed to investigate the association of TRI with in-hospital complications in dialysis patients undergoing PCI.

Methods and results

We included 44 462 patients on dialysis who underwent PCI using Japanese nationwide PCI registry data (2019-21) regardless of acute or chronic coronary syndrome. Patients were categorized based on access site: TRI, transfemoral intervention (TFI). Periprocedural access site bleeding complication requiring transfusion was the primary outcome and in-hospital death, and other periprocedural complications were the secondary outcomes. Matched weighted analysis was performed for TRI and TFI. Here, 8267 (18.6%) underwent TRI, and 36 195 (81.4%) underwent TFI. Patients who received TRI were older and had lower rates of comorbidities than those who received TFI. Access site bleeding rate and in-hospital death were significantly lower in the TRI group (0.1% vs. 0.7%, P < 0.001; 1.8% vs. 3.2%, P < 0.001, respectively). After adjustment, TRI was associated with a lower risk of access site bleeding (odds ratio [OR] [95% confidence interval (CI)]: 0.19 [0.099-0.38]; P < 0.001) and in-hospital death (OR [95% CI]: 0.79 [0.65-0.96]; P = 0.02). Other periprocedural complications between TRI and TFI were not significantly different.

Conclusion

In patients undergoing dialysis and PCI, TRI had a lower risk of access site bleeding and in-hospital death than TFI. This suggests that TRI may be safer for this patient population.

Longitudinal micro-incision creation prior to balloon angioplasty for treatment of arteriovenous access dysfunction in a real-world patient population: 6-month cohort analysis

INTRODUCTION

Routine hemodialysis depends on well-functioning vascular access. In the event of vascular access dysfunction, percutaneous transluminal balloon angioplasty (PTA) is conducted to restore patency. Although an angioplasty procedure can provide an excellent immediate result by opening the access to allow dialysis to continue, the long-term patency rates are less than satisfactory. The goal of this study was to assess the outcomes of patients who underwent a novel vessel preparation via longitudinal, controlled-depth micro-incisions prior to PTA.

METHODS

This multicenter, prospective, observational registry enrolled hemodialysis patients scheduled to undergo PTA of their arteriovenous fistula or graft due to clinical or hemodynamic abnormalities. A primary endpoint was anatomic success, defined as angiographic confirmation of <30% residual stenosis post-procedure without an adverse event. Additional assessments included device technical success, clinical success, freedom from target lesion revascularization, target lesion primary patency, and circuit primary patency at 6 months.

FINDINGS

A total of 148 lesions were treated with the FLEX Vessel Prep™ System (FLEX VP) prior to PTA in 114 subjects at eight clinical sites. Target lesions were 21 ± 25 mm in length with mean pre-procedure stenosis of 75.2% ± 4.7%. Five procedural complications were recorded without serious adverse events. Two subjects did not complete the follow-up evaluation. Target lesion primary patency across all subjects at 6-months was 62.2% with mean freedom from target lesion revascularization of 202.7 days. Target lesion primary patency and freedom from target lesion revascularization for AVF cases (n = 72) were 67.5% and 212.9 days, respectively. Target lesion primary patency and freedom from target lesion revascularization for AVGs (n = 42) were 52.4% and 183.3 days, respectively. In cases treating AVF cephalic arch stenosis (n = 25), 6-month target lesion primary patency was 70.6% and freedom from target lesion revascularization was 213.4 days.

DISCUSSION

This FLEX-AV registry demonstrates safety and effectiveness, notably in the cephalic arch and AVGs, when FLEX VP is used prior to PTA for treatment of vascular access dysfunction in a population of end-stage renal disease subjects.

Endovascular salvage of failing arterio-venous fistulas utilising sirolimus eluting balloons: Six months results from the ISABELLA trial

BACKGROUND

Aim of this pilot clinical study was to evaluate the safety and efficacy of the Selution Sustained Limus Release (SLR)™ sirolimus-eluting balloon (SEB) for improving failing arterio-venous fistulas (AVF) patency in Asian haemodialysis patients.

METHODS

Prospective single-centre, multi-investigator, non-consecutive, non-blinded single arm trial. Forty end-stage renal failure Asian patients with a dysfunctional AVF underwent SEB angioplasty between May and November 2020. All stenotic lesions were prepared with high pressure non-compliant balloon angioplasty prior to SEB angioplasty. Endpoints of interest included target lesion primary patency and circuit access patency and safety through 30 days. All patients received dual antiplatelet therapy for 1 month and were followed up with Duplex ultrasound at 6 months.

RESULTS

There was one subject dropout so final n = 39 patients (mean age 65.0 ± 11.9; males = 26 (66.7%)) and n = 43 target lesions treated. Main indication for intervention was dropping access flow (24/39; 61.5%) and most common target lesion was in the juxta-anastomosis (24/43; 54.5%). There was 100% technical and procedural success. There were no adverse events related to the SEB. Target lesion primary patency rates at 3 and 6 months were 39/41 (95.1%) and 28/39 (71.8%) respectively. Access circuit patency rates at 3 and 6 months were 35/37 (94.6%) and 22/35 (62.9%) respectively. There were 3 (7.7%) deaths all attributable to patients' underlying co-morbidities.

CONCLUSIONS

Fistuloplasty using the novel Selution SLR™ SEB for dysfunctional AVF circuits seems a safe and effective modality in Asian haemodialysis patients at 6 months but larger randomised controlled studies are required now to determine its true efficacy against plain balloon angioplasty.

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.

Use of the helical SUPERA™ stent and Passeo-18 Lux™ drug-coated balloon to treat recurrent cephalic arch stenosis for dysfunctional brachiocephalic fistulas: 1 year results of the Arch V SUPERA-LUX study

BACKGROUND

Aim of Arch V SUPERA-LUX was to evaluate the safety and efficacy of the combination therapy of SUPERA™ (Abbott Vascular, Santa Clara, CA, USA) helical stent implantation and Passeo-18 Lux™ (Biotronik Asia Pacific Pte Ltd, Singapore) drug coated balloon (DCB) elution to treat recurrent cephalic arch stenosis (CAS) in the setting of AV access dysfunction.

METHODS

Investigator-initiated, single-center, single-arm prospective pilot study of 20 end-stage renal failure Asian patients with a dysfunctional brachiocephalic fistula. All had symptomatic recurrent CAS within 6 months of prior intervention. The lesion was pre-dilated with a standard high-pressure balloon (Biotronik Passeo-35 HP balloon). The DCB (Passeo-18 Lux™) is subsequently inflated and the SUPERA™ stent deployed to sit 2 mm distal to the cephalic arch and covering the CAS but within the DCB zone. All patients were prescribed dual antiplatelet therapy for 3 months and followed up with Duplex ultrasound at 6- and 12-months.

RESULTS

There were 9 (45%) males and mean age was 67 ± 11.0 years. Mean time from prior procedure was 113 ± 68 days and main indication for reintervention was high venous pressure (9/20, 45%). Technical success was 100% and there were no peri-procedural complications related to either stent or DCB deployment. Target lesion primary patency at 6- and 12-months was 10/18 (55%) and 5/16 (31%), respectively. Mean time to target lesion re-intervention was 170 ± 82 days. Circuit access patency was 8/18 (44%) and 2/16 (13%) at 6- and 12-months respectively and mortality was 3/20 (15%) attributed to the patients' underlying co-morbidities.

CONCLUSION

Dual prong strategy of using SUPERA™ stenting and Passeo-18 Lux™ drug elution for recurrent CAS, although safe, was no more efficacious than conventional balloon angioplasty or stenting alone. Development of an intense inflammatory reaction within the stent led to reinterventions of a number of cases with suboptimal results.

Intervention with selution SLR™ Agent Balloon for Endovascular Latent Limus therapy for failing AV Fistulas (ISABELLA) Trial: Protocol for a pilot clinical study and pre-clinical results

BACKGROUND

The aim of this pilot clinical study is to evaluate the safety and efficacy of the Selution Sustained Limus Release (SLR)™ sirolimus-coated balloon (M.A. MedAlliance SA, Nyon, Switzerland) for improving the patency of failing arterio-venous fistulas (AVF) in hemodialysis patients. We also present herein a pre-clinical pharmacokinetic and safety evaluation of Selution™ to justify its first use in hemodialysis patients for endovascular access salvage.

METHODS AND RESULTS

This is an investigator-initiated prospective single-center, non-blinded single-arm trial. Forty patients with clinically significant de novo or recurrent stenoses in a mature AVF circuit will be recruited. All stenotic lesions will be prepared with high pressure non-compliant conventional balloon angioplasty (CBA) prior to deployment of the Sustained-Release Selution™ sirolimus drug-eluting balloon. The primary efficacy endpoint is 6-month target lesion primary patency and the primary safety endpoint is freedom from localized or systemic serious adverse events through 30 days. Secondary endpoints of interest include technical and clinical success rates and circuit access patency at 3 and 6 months. Follow-up will occur for 2 years for those patients whose AVFs remain patent. Pharmacokinetic and histological animal safety studies performed with the Selution™ coating formulation showed prolonged arterial tissue retention of sirolimus with therapeutic levels up to 60 days and non-toxic and rapidly declining blood levels. Histological results in animal models demonstrated safety, freedom from intraluminal thrombus, reduction in restenosis by sirolimus elution compared to CBA, and no evidence of embolic phenomena indicative of adverse particulate effects.

DISCUSSION

Long release sirolimus coated balloons may serve as a promising novel alternative therapy to paclitaxel-based technology for treating conduit stenosis secondary to neointimal hyperplasia. Pre-clinical pharmacokinetic and histological animal data are encouraging and provide suggestion of safety and efficacy in this setting. This single-center trial will provide a first step toward demonstration of efficacy and safety of this device for treatment of stenotic fistulas.

IN.PACT AV access randomized trial: Japan cohort outcomes through 12 months

PURPOSE

There is a lack of adjudicated and prospectively randomized published outcomes on the use of drug-coated balloons (DCB) to treat dysfunctional arteriovenous fistula in Asian patients. This post hoc subgroup analysis of 112 Japanese participants from the global IN.PACT AV Access trial reports outcomes through 12 months.

MATERIALS AND METHODS

Participants were treated with DCB (n = 58) or standard non-coated percutaneous transluminal angioplasty (PTA) balloons (n = 54). Outcomes included target lesion primary patency (TLPP), access circuit primary patency, and safety.

RESULTS

Through 6 months, TLPP was 86.0% (49/57) in the DCB group and 49.1% (26/53) in the PTA group (p < 0.001). Through 12 months, TLPP was 67.3% (37/55) in the DCB group and 43.4% (23/53) in the PTA group (p = 0.013).

CONCLUSION

In this post hoc analysis of Japanese participants from the IN.PACT AV Access trial, participants treated with DCB had higher TLPP through 6 and 12 months compared with PTA.

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.

Morphological Lesion Types Are Associated with Primary and Secondary Patency Rates after High-Pressure Balloon Angioplasty for Dysfunctional Arteriovenous Fistulas

BACKGROUND

Neointimal hyperplasia (NIH) is believed to be the main reason for arteriovenous fistula (AVF) dysfunction, but other mechanisms are also recognized to be involved in the pathophysiological process. This study investigated whether different morphological types of AVF lesions are associated with the patency rate after percutaneous transluminal angioplasty (PTA).

METHODS

This retrospective study included 120 patients who underwent PTA for autogenous AVF dysfunction. All the cases were evaluated under Doppler ultrasound (DU) before intervention and divided into 3 types: Type I (NIH type), Type II (non-NIH type), and Type III (mixed type). Prognostic and clinical data were analyzed by Kaplan-Meier analysis and the Cox proportional hazards model.

RESULTS

There was no statistical difference in baseline variables among groups, except for lumen diameter. The primary patency rates in Type I, Type II, and Type III groups were 78.4, 93.2, and 83.2% at 6 months and 59.5, 84.7, and 75.5% at 1 year, respectively. The secondary patency rates in Type I, Type II, and Type III groups were 94.4, 97.1, and 100% at 6 months and 90.5, 97.1, and 94.7% at 1 year, respectively. The Kaplan-Meier curve showed that the primary and secondary patency rates of Type I group were lower than those of Type II group. Multivariable Cox regression analysis demonstrated that postoperative primary patency was correlated with end-to-end anastomosis (hazard ratio [HR] = 2.997, p = 0.008, 95% confidence interval [CI]: 1.328-6.764) and Type I lesion (HR = 5.395, p = 0.004, 95% CI: 1.730-16.824).

CONCLUSIONS

NIH-dominant lesions of AVF evaluated by DU preoperatively were a risk factor for poor primary and secondary patency rate after PTA in hemodialysis patients.

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.

Restoring arteriovenous access: Pilot study using a scoring balloon in 50 patients

Background:

Arteriovenous access failure is most often due to the development of neointimal hyperplastic stenoses. Balloon angioplasty remains standard of care for endovascular treatment of stenoses obstructing blood flow in hemodialysis fistulas and grafts. Scoring balloon technologies have been developed to disrupt the atheromatous plaque and have shown to be safe and effective for treating stenosis in the hemodialysis access circuit. However, improvement in patency has yet to be established.

Methods:

This prospective, single-arm study included 50 patients with stenosed hemodialysis fistula/grafts treated with the AngioSculpt® scoring balloon (Philips) and followed for 6 months. The primary endpoint was target lesion primary patency at 2 and 6 months defined as freedom from re-intervention.

Results:

Treatment with the scoring balloon resulted in a reduction in stenosis from 78% ± 13.36% to 7.2% ± 7.57% (mean ± standard deviation). Scoring balloon inflation pressures averaged 11.4 atm; no slippage/dissections occurred. After 2 months, 10% of patients required re-intervention. At 6 months, 19% of patients required re-intervention. The 6-month freedom from re-intervention rate was higher for patients with stenosed fistulas (83.3%) compared to patients with stenosed grafts (71.4%). Six-month patency rates were highest for patients with no or one previous intervention (91.6% and 90.0%, respectively); patients with two to five preceding interventions had a 6-month patency rate of 80%, and those with more than five previous interventions had a 50% 6-month patency rate.

Conclusion:

Results from this pilot study suggest that the AngioSculpt scoring balloon may be a viable treatment option for stenosed arteriovenous fistula/graft access.

Efficacy and safety of secondary procedures for maintaining arteriovenous hemodialysis access patency: protocol for a systematic review and network meta-analysis

BACKGROUND

Arteriovenous (AV) hemodialysis access creation is recommended by international guidelines as the preferred method of hemodialysis access. However, most AV access sites will require revision to maintain patency. Although several treatment options exist, many have not been directly compared. We intend to compare the relative effectiveness of methods to maintain post-intervention primary patency of failing AV access.

METHODS

We will search EMBASE, MEDLINE, CENTRAL, trial registries, the grey literature, and ancestry and citation search from January 1977 to present, for randomized controlled trials comparing interventions to maintain primary patency of AV access. Two investigators will independently and blindly review all identified citations and extract data from included studies. The primary outcome is the primary patency 6 months after intervention. Secondary outcomes include immediate technical and functional success, reinterventions, patency, and mortality. Risk of bias, subgroup analyses, and sensitivity analyses are planned.

DISCUSSION

There are a number of treatment modalities for the management of failing AV access. However, most modalities have only been directly compared with plain old balloon angioplasty, and currently synthesized evidence focuses on individual pairwise comparisons. In light of the lack of comprehensively synthesized evidence and clinical equipoise, our study intends to synthesize currently available evidence though it is unclear which treatment modality is most effective.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ID CRD42020148224.

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.

Paclitaxel drug-coated balloon angioplasty for the treatment of failing arteriovenous fistulas: a single-center experience

Objectives: To report our experience of angioplasty with Lutonix (Bard Peripheral Vascular, Inc., Tempe, AZ) drug-coated balloon (DCB) for the treatment of failing arteriovenous fistulas (AVF).Materials and methods: Retrospective, single-center analysis consisting of 14 patients treated with Lutonix paclitaxel DCBs in the period from July 2015 through April 2017. We analyzed technical success, clinical success, primary patency of the target lesion, primary patency of the dialysis circuit, and the rate of complications. Regular follow-up of AVF patency was realized by clinical examination and duplex ultrasonography. The Kaplan-Meier survival method was applied to determine the cumulative primary patency of the target lesion and the dialysis circuit.Results: Technical success was 100% and clinical success 92.9%. There were no major or minor complications. Cumulative target lesion primary patency after DCB was 69.2% at 6 months and 31.6% at 12 months. Cumulative vascular circuit primary patency was 61.5% at 6 months and 31.6% at 12 months.Conclusion: Compared to results reported in literature with plain old balloon angioplasty (POBA), Lutonix paclitaxel DCB angioplasty proved a short-term patency benefit in treatment of dialysis AVF stenosis.

Use of Paclitaxel Coated Drug Eluting Technology to Improve Central Vein Patency for Haemodialysis Access Circuits: Any Benefit?

Purpose

Central venous stenosis is a recurring problem affecting dialysis access patency. Increasing evidence suggests that the use of drug-coated balloons (DCBs) improves target lesion primary patency (TLPP) in dialysis access. However, few studies have investigated the use of DCBs specifically in central venous stenosis. Thus, this study presents our initial experience with DCBs in the central vein of a dialysis access circuit.

Materials and Methods

This is a retrospective cohort study of all hemodialysis patients who underwent central vein angioplasty with DCB between February 2017 and March 2018 at Singapore General Hospital. We compared the primary patency post DCB angioplasty to the primary patency of the patient’s previous plain old balloon angioplasty (POBA).

Results

We observed a 100% anatomic and procedural success rate with no complications. The median follow-up period was 151 days (interquartile range, 85.5-234 days) and no patients were lost to follow-up. The 30- and 90-day TLPPs after DCB were 93.3% and 75.7%, respectively. The mean primary patency in our study group post-DCB during the follow-up period was 164 days (vs. 140 days in the POBA group). However, no statistically significant difference was detected.

Conclusion

DCB showed a similar TLPP to that for POBA in treating central venous stenosis with a trend toward a longer re-intervention-free period for DCB. However, there were numerous confounding factors and a well-designed randomized controlled trial is warranted to assess the true utility of DCB in treating central venous stenosis.

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.

Comparison of drug-coated balloon angioplasty versus conventional angioplasty for arteriovenous fistula stenosis: Systematic review and meta-analysis

BACKGROUND

Arteriovenous fistula is the most preferred form of vascular access, but stenosis treated by balloon angioplasty is prone to restenosis. Multiple trials have been published with regard to the use of paclitaxel-coated balloon to prolong lesion patency compared to conventional balloon. Although paclitaxel-coated balloon has theoretical appeal, its use has not been widespread nationwide due to cost and lack of large-scale multicenter studies. We performed this meta-analysis to evaluate whether paclitaxel-coated balloon outperforms conventional balloon to prolong target lesion patency.

METHODS

PubMed/Medline, Clinical Trials.gov, EMBASE, Scopus, Web of Science, and Cochrane Central were searched from inception through April 2019 for studies that investigated the use of paclitaxel-coated balloon in arteriovenous fistula.

RESULTS

Ten studies were included in the final meta-analysis: six studies were randomized controlled trials and four studies were cohort studies. There were 911 participants with a mean age of 64.78 (±5.96) years, and 61.89% were male. Outcome of interest was target lesion primary patency, recorded at 1, 3, 6, 7, 12, and 24 months. Meta-analysis of randomized controlled trials shows that paclitaxel-coated balloons did not statistically improve target lesion primary patency compared to conventional balloons at months 1 (odds ratio = 1.54, p = 0.6373), 3 (odds ratio = 0.57, p = 0.0575), 6 (odds ratio = 0.65, p = 0.3644), 7 (odds ratio = 0.63, p = 0.0582), 12 (odds ratio = 0.64, p = 0.0612), and 24 (odds ratio = 0.43, p = 0.3452). Effect of paclitaxel-coated balloons was statistically significant for cohort studies at months 6 (odds ratio = 0.26, p = 0.0007), 12 (odds ratio = 0.21, p = 0.0001), and 24 (odds ratio = 0.23, p = 0.01).

CONCLUSION

Paclitaxel-coated balloon showed no statistically significant improvement over conventional balloons in decreasing fistula stenosis in randomized controlled trial but were significant for cohort studies.

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.

Effect of combination of non-slip element balloon and drug-coating balloon for in-stent restenosis lesions (ELEGANT study)

BACKGROUND

In-stent restenosis (ISR) remains a problematic issue of coronary intervention. The non-slip element balloon (NSE) is a balloon catheter with 3 longitudinal nylon elements which are attached proximally and distally to the balloon component. The expectation is that this design of balloon is able to achieve a larger lumen area due to the elements, as well as reducing balloon slippage. We investigated whether NSE pre-dilatation improves angiographic outcomes compared to a high pressure non-compliant balloon pre-dilatation, followed by a drug-coating balloon (DCB) for treatment of ISR lesions with optical coherence tomographic imaging (OCT).

METHODS

Patients were eligible for the study if one or more in-stent restenosis lesions were treated with a paclitaxel-coating balloon. Patients were randomized to NSE pre-dilatation (NSE group) or high pressure non-compliant balloon pre-dilatation (POBA group) in a 1:1 fashion in 17 hospitals. The primary endpoint was in-segment late loss [post minimal lumen diameter (MLD)-follow-up MLD] at 8 months.

RESULTS

One hundred and five patients were allocated to each group. Balloon slippage (7.9% versus 22.9%, p=0.002) and geographical miss (6.9% versus 21.9%, p=0.002) were observed less in the NSE group compared to the POBA group. Acute gain was significantly larger in the NSE group (1.17±0.42mm versus 1.06±0.35mm, p=0.04), but post minimum stent lumen area analyzed by OCT was similar between the two groups (3.85±1.67mm² versus 3.81±1.93mm², p=0.64). At 8 months, average lesion length was significantly shorter than the POBA group (5.78±3.26mm versus 6.97±4.59mm, p=0.04), but average in-segment late loss was similar between the two groups (0.28±0.45mm versus 0.27±0.38mm, p=0.75).

CONCLUSION

Eight-month angiographic outcomes were similar between NSE and non-compliant balloon pre-dilatation with DCB for treatment of ISR lesions. However, NSE pre-dilatation has advantages such as reduction of balloon slippage and geographical miss during the procedure.

Elevated Platelet Galectin-3 and Rho-Associated Protein Kinase Activity Are Associated with Hemodialysis Arteriovenous Shunt Dysfunction among Subjects with Diabetes Mellitus

Introduction

Hyperglycemia is a major factor in influencing the patency rate of arteriovenous shunts, potentially associated with the RhoA/Rho-associated protein kinase (ROCK) pathway. Besides, galectin-3 mediates thrombotic mechanisms in venous thrombosis and peripheral artery disease. We hypothesized that high ROCK activity and galectin-3 levels are associated with arteriovenous shunt dysfunction.

Methods

We prospectively enrolled 38 patients diagnosed with arteriovenous shunt dysfunction. 29 patients received a complete follow-up and each provided two blood samples, which were collected at the first visit for occluded status of arteriovenous shunts and 1 month later for patent status. A Western blot assay for a myosin phosphatase target subunit (MYPT) was performed to examine Rho-kinase activity. A Western blot assay for platelet galectin-3 and enzyme-linked immunosorbent assay (ELISA) for circulating galectin-3 were completed.

Results

Higher platelet MYPT ratios and galectin-3 levels were identified at occluded arteriovenous shunts (MYPT ratio: 0.5 [0.3-1.4] vs. 0.4 [0.3-0.6], p = 0.01; galectin-3: 1.2 [0.4-1.6] vs. 0.7 [0.1-1.2], p = 0.0004). The plasma galectin-3 binding protein ELISA was also higher at occluded arteriovenous shunts (8.4 [6.0-9.7] μg/mL vs. 7.1 [4.5-9.1] μg/mL, p = 0.009). Biomarker ratios (occluded/patent status) trended high in patients with poorly controlled diabetes (MYPT ratio: 1.7 [1.0-3.0] vs. 1.1 [0.7-1.3], p = 0.06; galectin-3: 1.6 [1.3-3.4] vs. 1.1 [0.8-1.9], p = 0.05).

Conclusion

High platelet ROCK activity and galectin-3 levels are associated with increased risk in arteriovenous shunt dysfunction, especially in patients with poorly controlled diabetes.

Clinical Evaluation of the Cook Advance Enforcer 35 Focal-Force PTA Balloon Catheter for Treatment of Hemodialysis Fistula Stenoses: A Feasibility Study

PURPOSE

A prospective, single-center, single-arm feasibility study evaluated procedural and short-term performance of the Advance Enforcer 35 focal-force percutaneous transluminal angioplasty (PTA) balloon catheter in treating stenoses of mature native arteriovenous (AV) hemodialysis access circuits.

MATERIALS AND METHODS

Twenty-eight patients undergoing treatment for stenosis of a mature native AV hemodialysis access circuit were enrolled at a single institution. Angiographic assessments of the study lesion were required at baseline and after the procedure. Adjunctive procedures for significant residual stenosis were permitted, and patients had clinical and imaging follow-up for as long as 6 months.

RESULTS

Treatment with the study balloon was effective in reducing the average percent diameter stenosis of the treated lesion from 66.3% (range, 43.8%-93.3%) before the procedure to 23.7% (range, -6.7% to 51.4%) after the procedure. The average inflation pressure required was 12.3 atm. Only 1 patient required an adjunctive procedure, and all patients could resume normal dialysis following the study procedure. At 3 months, 62.0% of study lesions remained patent, and the 6-month patency rate was 25.1%. Two adverse events associated with the study procedure were reported: access-site hematoma and forearm pain (3.6% each).

CONCLUSIONS

The results demonstrate safety of the study balloon in treating AV access stenosis. Nominal-diameter angioplasty was achieved at relatively low pressure in most study patients without the use of adjunctive procedures, and resumption of normal dialysis was achieved for all patients.

Fistuloplasty using a radiation-and-time-saving sheathless balloon catheter

Introduction:

Sheath placement in dialysis access interventions is traditionally necessary to obtain imaging, guide percutaneous angioplasty, and evaluate results. The aim of this study was to assess the feasibility of performing sheathless Arterio-venous (AV) access interventions using a novel percutaneous angioplasty balloon catheter.

Methods:

Between May and September 2017, data on all dialysis access interventions using a novel percutaneous angioplasty balloon with a dedicated injection port were collected. All procedures were performed without a sheath. Success was established as no conversion to sheath placement. Demographic data, location of lesion, time to perform procedure, amount of contrast used, radiation exposure, and access complications were recorded. Ultrasound was used to evaluate access site complications.

Results:

Sheathless interventions were successful in 24 patients with the mean age of 62 years (29–94). There were 5 PTFE grafts and 19 native fistulas. Lesions were located anywhere from the arterial anastomosis to the cephalic arch. The average balloon size was 6 mm (5–7 mm), and the procedure time was 15.8 min (8–45 min). No access site complications were observed.

Conclusion:

Sheathless intervention is feasible with several potential advantages, including short procedure time, minimal contrast volume, and reduced radiation exposure. Finally, the lower profile at the access site may result in fewer complications.

Drug-Coated Versus Plain Balloon Angioplasty In Arteriovenous Fistulas: A Randomized, Controlled Study With 1-Year Follow-Up (The Drecorest Ii-Study)

Background and Aims:

Stenosis due to intimal hyperplasia and restenosis after initially successful percutaneous angioplasty are common reasons for failing arteriovenous fistulas. The aim of this study was to evaluate the effect of drug-coated balloons in the treatment of arteriovenous fistula stenosis.

Design:

Single-center, parallel group, randomized controlled trial. Block randomized by sealed envelope 1:1.

Materials and Methods:

A total of 39 patients with primary or recurrent stenosis in a failing native arteriovenous fistulas were randomized to drug-coated balloon (n = 19) or standard balloon angioplasty (n = 20). Follow-up was 1 year. Primary outcome measure was target lesion revascularization.

Results:

In all, 36 stenoses were analyzed; three patients were excluded due to technical failure after randomization. A total of 88.9% (16/18) in the drug-coated balloon group was revascularized or occluded within 1 year, compared to 22.2% (4/18) of the stenoses in the balloon angioplasty group (relative risk for drug-coated balloon 7.09). Mean time-to- target lesion revascularization was 110 and 193 days after the drug-coated balloon and balloon angioplasty, respectively (p = 0.06).

Conclusions:

With 1-year follow-up, the target lesion revascularization-free survival after drug-coated balloon-treatment was clearly worse. The reason for this remains unknown, but it may be due to differences in the biological response to paclitaxel in the venous arteriovenous fistula-wall compared to its antiproliferative effect in the arterial wall after drug-coated balloon treatment of atherosclerotic occlusive lesions. Trial registration: ClinicalTrials.gov NCT03036241

Treatment of juxta-anastomotic stenoses for failing distal radiocephalic arteriovenous fistulas: Drug-coated balloons versus angioplasty

The aim of our study is to report the results of two types (type A, type B) paclitaxel drug-coated balloon compared with standard percutaneous transluminal angioplasty in the treatment of juxta-anastomotic stenoses of mature but failing distal radiocephalic hemodialysis arteriovenous fistulas. Two groups of 26 and 44 patients treated with two different drug-coated balloon are compared with a control group of 86 treated with standard percutaneous transluminal angioplasty. A color Doppler ultrasound was performed to evaluate stenosis and for treatment planning. We assess primary patency, defined as the absence of dysfunction of the arteriovenous fistulas, patent lesion or residual stenosis < 30% and no need for further reintervention of target lesion. Primary patency and secondary patency are evaluated after 12 months with color Doppler ultrasound for the whole arteriovenous fistulas, defined as absolute (absolute primary patency, absolute secondary patency) and target lesion. Postprocedural technical and clinical success was 100%. After 12 months, absolute primary patency is 81.8% for type A, 84.1% type B, and 54.7% for standard percutaneous transluminal angioplasty; target lesion primary patency is 92% type A, 86.4% type B, and 62.8% standard percutaneous transluminal angioplasty; absolute secondary patency is 95.4% type A, 95.5% type B, and 80.7% standard percutaneous transluminal angioplasty; target lesion secondary patency is 100% type A, 97.7% type B, and 80.7% standard percutaneous transluminal angioplasty. All the patients treated with drug-coated balloon (type A + type B) have an absolute primary patency of 83.3%, a target lesion primary patency of 87.9%, an absolute secondary patency of 95.5%, and a target lesion secondary patency of 98.4%. Our study confirms that the use of drug-coated balloon, indiscriminately among different brands, improves primary patency with statistically significant difference in comparison with standard percutaneous transluminal angioplasty and decreases reintervention of target lesion in juxta-anastomotic stenoses of failing distal arteriovenous fistulas maintaining the radiocephalic fistula as long as possible.

A Review of Percutaneous Transluminal Angioplasty in Hemodialysis Fistula

The number of patients in dialysis increases every year. In this review, we will evaluate the role of percutaneous transluminal angioplasty (PTA) according to patency of arteriovenous fistula and grafts. The main indication of PΤΑ is stenosis > 50% or obstruction of the vascular lumen of an arteriovenous fistula and graft. It is usually performed under local anesthesia. The infection rate is as low as the number of complications. Fistula can be used in dialysis in the same day without the need for a central venous catheter. Primary patency is >50% in the first year while primary assisted patency is 80-90% in the same time period. Repeated PTA is as durable as the primary PTA. An early PTA carries a risk of new interventions. Cutting balloon can be used as a second-line method. Stents and covered stents are kept for the management of complications and central outflow venous stenosis. PTA is the treatment of choice for stenosis or obstruction of dialysis fistulas. Repeated PTA may be needed for better patency. Drug eluting balloon may become the future in PTA of dialysis fistula, but more trials are needed.

Predicting Technical Success after Fistuloplasty: An Analysis of 176 Procedures

BACKGROUND

Significant stenoses in arteriovenous fistulae (AVFs) or arteriovenous grafts (AVGs) with limitation of flow and dialysis inadequacy should prompt consideration for fistuloplasty. We sought to identify fistulae, lesions, and patient-specific variables, which predict for outcomes after fistuloplasty.

METHODS

Data were extracted retrospectively from a renal access database from 2011 to 2016 of patients undergoing fistuloplasty. Demographics, comorbidities, outcomes of intervention, and flow rates documented on preintervention and postintervention duplex were collected. Secondary analysis of factors associated with postfistuloplasty flow rates of >600 mL/min, previously shown to be predictive of not requiring future intervention, was performed.

RESULTS

Of 204 attempted fistuloplasties, 176 were completed. One hundred forty (79.5%) were native AVFs and 34 (19.3%), AVGs (no data for 2). Median stenosis treated was 75%, with a majority (43.8%) in the proximal outflow vein. Flow rate on duplex after fistuloplasty was significantly better in AVFs (mean improvement 189.2 mL/min) than that in AVGs (mean improvement 51.8 mL/min; P = 0.034). Greatest flow improvement occurred for needling site stenotic lesions compared with other locations (from anastomosis to central vein) but was not significant. Brachio-brachial or brachio-axillary AVGs did significantly (P < 0.05) worse than all other fistulae types. The presence of hypertension was predicted for postfistuloplasty flow rate of >600 mL/min.

CONCLUSIONS

Flow rates after fistuloplasty vary depending on the type of fistula treated and the presence of hypertension. Knowledge of this can lead to better patient selection and counseling for fistuloplasty.

Impact of Lesion Morphology on Durability After Angioplasty of Failed Arteriovenous Fistulas in Hemodialysis Patients

PURPOSE

To investigate if morphological patterns of arteriovenous fistula (AVF) venous lesions affect primary patency after percutaneous transluminal angioplasty (PTA).

METHODS

From July 2014 to June 2015, 262 patients underwent PTA for failed AVFs. A total of 104 patients were excluded owing to (1) calcification or AVF occlusion precluding ultrasound examination, (2) central venous or arterial lesions, and (3) no follow-up, leaving 158 patients (mean age 71±12; 96 men) for analysis. More than half of the patients had one or more previous PTAs for the failed AVF. Prior to PTA the stenotic lesions were assessed using ultrasonography to determine stenotic patterns at the minimum lumen area site and to evaluate the flow volume in the brachial artery. Three stenotic patterns were identified: intimal hyperplasia (IH) stenosis (n=110), shrinking lumen stenosis (n=32), and venous valve-related stenosis (n=16). The main outcome measure was primary patency after PTA estimated using Kaplan-Meier analysis. Predictors for loss of primary patency were determined using a multivariate Cox proportional hazards model; the results are presented as the adjusted hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Median follow-up after PTA was 6.3 months (interquartile range 3.3, 10.5). The 6-month primary patency estimates were 56%±5% in the IH group, 40±9% in the shrinking lumen group, and 100% in the valve stenosis group (IH vs shrinking, p=0.013; IH vs valve, p=0.003). In multivariate analysis, shrinking lumen morphology had a negative impact on primary patency (HR 2.05, 95% CI 1.25 to 3.36, p=0.005), while venous valve-related stenosis had a positive impact (HR 0.19, 95% CI 0.04 to 0.79, p=0.023). Flow volume (10-mL/min increments; HR 0.97, 95% CI 0.96 to 0.99, p=0.004) and history of PTA (HR 1.66, 95% CI 1.06 to 2.60, p=0.029) were also independently associated with primary patency after PTA.

CONCLUSION

The patterns of AVF stenosis as determined by ultrasound can affect the outcome of treatment with balloon dilation.

Drug eluting balloon angioplasty for assisted maturation of failing fistulae

OBJECTIVE

To present our experience of balloon-assisted maturation with drug-eluting balloon dilation in patients with recurrent failing arteriovenous fistulae.

CASE SERIES

Three patients (all males, mean age 71 years) with a complex history of failed attempts at native fistula creation underwent surgical creation of arteriovenous fistulae. Two patients had a two-stage brachio-brachial fistula and 1 had a brachio-cephalic fistula that also required subsequent elevation. After a few weeks of preserved patency with a thrill detected clinically, all patients had a gradual deterioration of flow manifested with loss of thrill and multiple severely stenotic lesions of neo-intimal hyperplasia seen on duplex ultrasound. All 3 non-maturing native arteriovenous fistulae had 1 or more angioplasties with regular balloons that were initially successful; however, they rapidly deteriorated with a loss of thrill and a recurrence of multiple stenosis. Drug-eluting balloon dilation was used subsequently as a last resort to save these failing fistulae. All procedures were successful with the preservation of patency and adequate fistula flow (>600 mL/min) during the follow-up period (4-8 months, mean 6 months), and all patients received successful dialysis with 2-needle cannulation of their fistulae. There were no adverse events during the study period.

CONCLUSIONS

Drug-eluting balloon angioplasty was to salvage nonmaturing fistulae with durable results in complex patients where conventional treatment had previously failed. Drug-eluting balloons may provide a useful treatment option for patients prone to multiple access failures due accelerated neo-intimal hyperplasia.

Cardiovascular Disease in Patients with End-Stage Renal Disease on Hemodialysis

Cardiovascular disease is a major concern for patients with end-stage renal disease (ESRD), especially those on hemodialysis. ESRD patients with coronary artery disease often do not have symptoms or present with atypical symptoms. Coronary lesions in ESRD patients are characterized by increased media thickness, infiltration and activation of macrophages, and marked calcification. Several studies showed worsened clinical outcomes after coronary revascularization, which were dependent on the severity of renal dysfunction. ESRD patients on hemodialysis have the most severe renal dysfunction; thus, the clinical outcomes are worse in these patients than in those with other types of renal dysfunction. Medications for primary or secondary cardiovascular prevention are also insufficient in ESRD patients. Efficacy of drug-eluting stents is inferior in ESRD patients, compared to the excellent outcomes observed in patients with normal renal function. Unsatisfactory outcomes with trials targeting cardiovascular disease in patients with ESRD emphasize a large potential to improve outcomes. Thus, optimal strategies for diagnosis, prevention, and management of cardiovascular disease should be modified in ESRD patients.

Usefulness of paclitaxel-releasing high-pressure balloon associated with cutting balloon angioplasty for treatment of outflow stenoses of failing hemodialysis arteriovenous shunts

AIM

To evaluate the technical and clinical success, primary patency (PP) and complications of angioplasty performed with paclitaxel-coated balloon (PCBs) associated with cutting balloon and for the treatment of the outflow stenoses of failing hemodialysis arteriovenous shunt.

MATERIAL AND METHODS

From September 2014 to September 2015, 50 patients with 66 stenoses were registered. Vascular accesses were autogenous (n = 20) and prosthetic (n = 30). Stenosis were documented during follow-up with routine echo-color Doppler, clinical evaluation and in the remaining incidentally during fistulography. Angioplasty was performed with cutting balloon and afterward with PCB. The mean follow-up time was 8 months (range 6-15 months). Technical success, clinical success, primary patency and complications were registered.

RESULTS

Technical success was 100 %. Clinical success was 94.7 %. Primary patency rate was 87.7 %; in five patients, a significant re-stenosis (≥50 %) was registered. A residual asymptomatic stenosis (<30 %) was registered in four cases (7 %). No major complications were registered.

CONCLUSIONS

A short-term patency benefit may be obtained including PCB in angioplasty treatment of failing hemodialysis arteriovenous shunts.

Future research directions to improve fistula maturation and reduce access failure

With the increasing prevalence of end-stage renal disease, there is a growing need for hemodialysis. Arteriovenous fistulae (AVF) are the preferred type of vascular access for hemodialysis, but maturation and failure continue to present significant barriers to successful fistula use. AVF maturation integrates outward remodeling with vessel wall thickening in response to drastic hemodynamic changes in the setting of uremia, systemic inflammation, oxidative stress, and pre-existent vascular pathology. AVF can fail due to both failure to mature adequately to support hemodialysis and development of neointimal hyperplasia that narrows the AVF lumen, typically near the fistula anastomosis. Failure due to neointimal hyperplasia involves vascular cell activation and migration and extracellular matrix remodeling with complex interactions of growth factors, adhesion molecules, inflammatory mediators, and chemokines, all of which result in maladaptive remodeling. Different strategies have been proposed to prevent and treat AVF failure based on current understanding of the modes and pathology of access failure; these approaches range from appropriate patient selection and use of alternative surgical strategies for fistula creation, to the use of novel interventional techniques or drugs to treat failing fistulae. Effective treatments to prevent or treat AVF failure require a multidisciplinary approach involving nephrologists, vascular surgeons, and interventional radiologists, careful patient selection, and the use of tailored systemic or localized interventions to improve patient-specific outcomes. This review provides contemporary information on the underlying mechanisms of AVF maturation and failure and discusses the broad spectrum of options that can be tailored for specific therapy.

Drug-coated balloon angioplasty for dialysis access fistula stenosis

Maintaining vascular access patency represents a tremendous challenge in hemodialysis patients. Although "native" arteriovenous fistula (AVF) is currently recommended as primary vascular access, neointimal hyperplasia stenoses frequently develop, with a risk for AVF thrombosis and vascular access loss. For years, first-line treatment of AVFs stenoses has been percutaneous transluminal angioplasty, generally with high-pressure or cutting uncoated balloons. However, restenosis and reintervention rates remain incredibly high and occur, according to recent studies, in up to 60% and 70% of patients at 6 and 12 months, respectively. Drug-coated balloons delivering paclitaxel at the angioplasty site have proved their superiority in the treatment of coronary and peripheral arterial stenoses. Paclitaxel reduces neointimal hyperplasia and drug-coated balloons, therefore, it represents an attractive option for AVF stenoses. Because data are scarce, the aim of this paper was to review the concepts and current results of drug-coated balloons in AVF stenosis management.