A systematic review and meta-analysis of drug-coated balloon versus conventional balloon angioplasty for dialysis access stenosis

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.

Management of thoracic outlet syndrome in patients with hemodialysis access

Patients with threatened arteriovenous access are often found to have central venous stenoses at the ipsilateral costoclavicular junction, which may be resistant to endovascular intervention. Stenoses in this location may not resolve unless surgical decompression of thoracic outlet is performed to relieve the extrinsic compression on the subclavian vein. The authors reviewed the management of dialysis patients with central venous lesions at the thoracic outlet, as well as the role of surgical decompression with first-rib resection or claviculectomy for salvage of threatened, ipsilateral dialysis access.

Comparison of Lower and Upper Extremity Arteriovenous Graft: A Retrospective Clinical Analysis with 5-Year Follow-Up

BACKGROUND

For patients in whom an upper extremity (UE) vascular access cannot be established, the lower extremity (LE) arteriovenous graft (AVG) could be selected. However, the application of LE AVG is limited owing to its high infection rate, uncertain patency time, and technical difficulties. This study aimed to compare the long-term patency rates and the incidence of vascular access complications of AVG in the LE and UE to provide a reference for the applications of AVG, especially in the LEs.

METHODS

This was a retrospective analysis of patients who successfully underwent LE or UE AVG placement from March 2016 to October 2021. Patient characteristics were collected and compared using parameter or nonparameter tests according to data type. Postoperative patency was evaluated using Kaplan-Meier test. Postoperative complication incidence density and intergroup comparison were estimated using the Poisson distribution.

RESULTS

Twenty-two patients with LE AVG and 120 patients with UE AVG were included. The 1-year primary patency rate was 67.4% (±11.0% standard error [SE]) in the LE group and 30.1% (±4.5% SE) in the UE group (P = 0.031). The assisted primary patency rate at postoperative months 12, 24, and 36 was respectively 78.6% (±9.6% SE), 65.5% (±14.4% SE), and 49.1% (±17.8% SE) in the LE group and 63.3% (±4.6% SE), 47.5% (±5.4% SE), and 30.4% (±6.1% SE) in the UE group (P = 0.137). The secondary patency rate at postoperative months 12, 24, and 36 remains 95.5% (±4.4% SE) in the LE group and 89.3% (±2.9% SE), 83.7% (±3.9% SE), and 73.0% (±6.2% SE), respectively, in the UE group (P = 0.200). Postoperative complications included stenosis, occlusion/thrombosis, infection, steal syndrome, pseudoaneurysm, severe postoperative serum swelling, and AVG exposure. The total incidence rates of postoperative complications were 0.87 (95% confidence interval [CI] 0.59-1.23) versus 1.61 (95% CI 1.45-1.79) (P = 0.001) cases/person-year, the incidence rates of stenosis were 0.45 (95% CI 0.26-0.73) versus 0.92 (95% CI 0.80-1.06) (P = 0.005) cases/person-year and the incidence rates of occlusion/thrombosis were 0.34 (95% CI 0.17-0.59) versus 0.62 (95% CI 0.52-0.74) cases/person-year in the LE group compared to those in the UE group (P = 0.041).

CONCLUSIONS

LE AVG had higher primary patency rate and lower postoperative complication incidence than UE AVG. With the development of interventional technology, both LE AVG and UE AVG exhibited high secondary patency rates. LE AVG can be a reliable and long-term alternative for appropriately selected patients with unusable UE vessels.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

Angioplasty for dysfunctional arteriovenous fistulas: A meta-analysis of recent randomized controlled trials compared paclitaxel-coated balloon versus conventional balloon angioplasty

BACKGROUND

Stenosis in arteriovenous fistulas (AVF) due to neointimal hyperplasia is one of the most common causes of hemodialysis vascular access dysfunction. Treating patients with dysfunctional AVF with drug-coated balloon (DCB) angioplasty may potentially improve outcomes.

OBJECTIVES

This systematic review aimed to compare the effectiveness and safety of DCB angioplasty versus conventional balloon angioplasty by pooling evidence from the most recent randomized controlled trials.

METHODS

We conducted a comprehensive literature search in the Web of Science, Embase, and Cochrane central databases. Two independent researchers screened the article, extracted interest, and evaluated included studies for risk of bias. Pooled estimation was conducted in terms of 6-month target-lesion primary patency (TLPP) and target-lesion reintervention (TLR), as well as other outcomes.

RESULTS

Results were expressed with odds ratio (OR) and 95% confidence interval (CI). A total of five RCTs were identified and included in the meta-analyses, with 1107 participants. DCB has a trend of a higher rate of TLPP (OR 1.79, 95% CI 0.66-4.90, p = 0.181) and a significantly lower rate of TLR (0.52, 95% CI 0.29-0.92, p = 0.034), as compared to conventional balloon angioplasty. No difference in the 6-month access circuit primary patency and reinvention was observed between the two groups.

CONCLUSION

DCB may be an alternative treatment of dysfunctional AVF given a trend of a higher rate of TLPP and a significantly lower rate of TLR than conventional balloon angioplasty within 6 months after the indexed procedure. Moreover, DCB was non-inferior to conventional balloon angioplasty in terms of safety. Considering variations in the DCB technique, further studies are warranted for a standardized process.

IN.PACT AV Access Randomized Trial of Drug-Coated Balloons for Dysfunctional Arteriovenous Fistulae: Clinical Outcomes through 36 Months

PURPOSE

To present the 36-month outcomes of the prospective randomized IN.PACT AV Access study of participants with obstructive de novo or restenotic native upper extremity arteriovenous dialysis fistula lesions treated with drug-coated balloon (DCBs) or standard percutaneous transluminal angioplasty (PTA) following successful high-pressure PTA.

MATERIALS AND METHODS

Participants at 29 international sites were randomized 1:1 to receive an IN.PACT AV DCB (n = 170) or undergo PTA (n = 160). The outcomes through 36 months included target lesion primary patency (TLPP) and access circuit primary patency (ACPP) (composites of clinically driven target lesion or access circuit revascularization and/or access circuit thrombosis), number of reinterventions, and serious adverse events involving the access circuit.

RESULTS

TLPP was 52.1% in the DCB group compared with 36.7% in the PTA group through 24 months and 43.1% in the DCB group compared with 28.6% in the PTA group through 36 months (both log-rank P < .001). ACPP was 39.4% in the DCB group compared with 25.3% in the PTA group through 24 months and 26.4% in the DCB group compared with 16.6% in the PTA group through 36 months (both log-rank P < .001). Cumulative incidence of access circuit thrombosis through 36 months was 8.2% in the DCB group compared with 18.3% in the PTA group (log-rank P = .040). Cumulative incidence of mortality through 36 months was 26.6% in the DCB group compared with 30.8% in the PTA group (log-rank P = .71).

CONCLUSIONS

This study demonstrated superior TLPP and ACPP with DCBs compared with PTA, with no difference in mortality through 3 years. Access circuit thrombosis was statistically significantly higher in the PTA group at 3 years.

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.

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).

Surgical Referral for Hemodialysis Access Maintenance

Hemodialysis access is the lifeline for end-stage renal disease patients. However, dialysis access is associated with a host of complications, including thrombosis, recurrent stenosis, infection, aneurysmal changes and bleeding. Although endovascular therapy remains the first-line treatment owing to its less invasive nature, there are certain situations where surgical referral is recommended or even necessary. Regardless, management of dialysis access complications requires a multidisciplinary approach. Interventional radiologists should be familiar with the appropriate timing for surgical referral to better serve the complex patient population.

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.

The role of stents in hemodialysis vascular access

Vascular access is the Achilles' heel of dialysis therapy among patient with end stage kidney disease. The development of neointimal hyperplasia and subsequent stenosis is common in vascular access and is associated with significant morbidity. Percutaneous transluminal angioplasty using balloon inflation was the standard therapy of these lesions. However, the balloon-based approaches were associated with poor vascular access patency rate necessitating new inventions. It is within this context that different types of stents were developed in order to improve the overall dialysis vascular access functionality. In this article, we review the available literature regarding the use of stents in treating dialysis vascular access stenotic lesions. Further, we review the major clinical trials of stent use in different anatomic locations and in different clinical scenarios.

IN.PACT AV Access Randomized Trial: 12-month Clinical Results Demonstrating the Sustained Treatment Effect of Drug-Coated Balloons

PURPOSE

To present twelve-month outcomes of the IN.PACT AV Access Study, a prospective, single-blinded trial enrolling participants with obstructive de novo or restenotic native upper extremity arteriovenous dialysis fistula lesions treated with drug-coated balloon (DCB) or percutaneous transluminal angioplasty (PTA).

MATERIALS AND METHODS

After successful high-pressure PTA, participants at 29 international sites were randomized 1:1 to treatment with IN.PACT AV DCB (n=170) or standard uncoated PTA (n=160). Outcomes at 12 months include target lesion primary patency (TLPP), defined as freedom from clinically-driven target lesion revascularization or access circuit thrombosis, access circuit primary patency (ACPP), number of reinterventions, and adverse events involving the access circuit.

RESULTS

At 12 months, TLPP was 63.8% (90/141) in the DCB group compared to 43.6% (61/140) in the PTA group (p<0.001). The total number of reinterventions required to maintain TLPP through 360 days was 93 in the DCB group and 144 in the PTA group, a 35.4% reduction in reinterventions when DCB was used. Access circuit thrombosis was 2.9% (4/138) in the DCB group and 6.2% (8/129) in the PTA group (p=0.19). Time to TLPP was assessed using a multivariable analysis to identify factors associated with loss of patency. Treatment device was the independent predictor with the largest effect, with a hazard ratio of 0.42 (95%CI [0.29, 0.64]; p<0.001).

CONCLUSION

TLPP was statistically significantly higher in DCB compared to standard PTA at 12 months, demonstrating the sustained and superior effectiveness of this device for the treatment of dysfunctional arteriovenous dialysis fistulas.

A single-centre, retrospective analysis of mortality over 80 months comparing paclitaxel-coated balloon versus standard balloon angioplasty in the treatment of dysfunctional arteriovenous access

AIM

Percutaneous transluminal angioplasty (PTA) is a standard treatment for arteriovenous fistula (AVF) stenosis to preserve haemodialysis vascular access, promoting improved dialysis adequacy and better outcomes for those dependent on renal replacement therapy. Drug coated balloons (DCB) may help reduce the rate of neointimal hyperplasia and recurrent stenosis, but their use in femoropopliteal angioplasty has been associated with increased mortality at 2 and 5 year follow-up. This study aims to address the long-term safety of PTA for AVF stenosis with clinical correlation to participant co-morbidity and mortality.

METHODS

All patients undergoing PTA for AVF stenosis at a single centre between 2013 and 2017 were identified and grouped according to the use of DCB versus standard balloon angioplasty. All data was anonymised and correlated to verify independent predictors of mortality.

RESULTS

481 (400 standard balloon; 81 DCB) procedures were performed in 313 patients (250 standard balloon; 63 DCB). Follow-up at 80 months did not show any difference in mortality (p = 0.546). Multivariate analysis identified time on dialysis (p < 0.001), age (p = 0.001) and Charlson comorbidity index (p = 0.02) as independent predictors of mortality.

CONCLUSIONS

In this study, mortality was not associated with the use of DCBs, but was related to established factors of dialysis longevity, age and comorbidity.

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.

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.

Sharp Needle Recanalization Technique for Peripheral Hemodialysis Arteriovenous Fistula Occlusion

PURPOSE

To determine the efficacy of a percutaneous sharp needle recanalization technique for the treatment of peripheral hemodialysis arteriovenous fistula (AVF) occlusion.

MATERIALS AND METHODS

This study included 13 patients (14 procedures) between May 2010 and February 2020 with non-thrombotic AVF occlusion wherein guidewire passage through the occluded segment had failed. We successfully passed the guidewire through the occluded segment using a sharp needle recanalization technique with Chiba or Colapinto needles, under ultrasound or fluoroscopic guidance. The type of AVF, site and length of occlusion, technical success, complications, and long-term patency were analyzed.

RESULTS

Technical success was achieved in 12 (85.7%) out of 14 procedures. The procedure failed in two patients due to the poor angle of approach in the axillary area and diffuse severe stenosis in the draining cephalic vein. In eight procedures, sharp needle recanalization was performed under ultrasound guidance, while the other six procedures were performed under fluoroscopic guidance. Chiba and Colapinto needles were used in five and nine procedures, respectively. The mean length of occlusion was 2.7 cm (range 1.8-4.2 cm). There was one case of mild complication, that is, mild contrast extravasation, which was treated by stent deployment. The post-intervention primary patency rates at 6 months, 1 year, and 2 years were 81.8%, 36.4%, and 18.2%, respectively.

CONCLUSION

The results of this limited series suggest that the sharp needle recanalization technique is a simple and effective method for the treatment of peripheral non-thrombotic AVF occlusion.

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.

New Devices and Technologies for Hemodialysis Vascular Access: A Review

In the United States, hemodialysis remains the most common treatment modality for kidney failure, chosen by almost 90% of incident patients. A functioning vascular access is key to providing adequate hemodialysis therapy. Recently, major innovations in devices and technology for hemodialysis vascular access care have rapidly changed the landscape. Novel endovascular devices for creation of arteriovenous fistulas may offer a solution to the barriers encountered in initiating maintenance hemodialysis with a permanent vascular access rather than a central venous catheter (CVC). Furthermore, in the prevalent hemodialysis population, the minimally invasive endovascular arteriovenous fistula procedure should help improve long wait times for vascular access creation, which remains a major barrier to reducing CVC dependence. Bioengineered grafts are being developed and may offer another option to polytetrafluoroethylene grafts. Early studies with these biocompatible grafts are promising, as additional studies continue to evaluate their clinical outcomes in comparison to cryopreserved or synthetic options. Prolonging the vascular access patency with appropriate use of devices such as drug-coated balloons and stent grafts may complement the novel techniques of creating arteriovenous access. Finally, innovative solutions to treat stenosed and occluded thoracic central veins can provide an approach to creating a vascular access and allow patients with exhausted vasculature to remain on hemodialysis. The robust developments in hemodialysis vascular access are likely to change practice patterns in the near future.

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.

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.

Early (6 months) results of a pilot prospective study to investigate the efficacy and safety of sirolimus coated balloon angioplasty for dysfunctional arterio-venous fistulas: MAgicTouch Intervention Leap for Dialysis Access (MATILDA) Trial

Background

The aim of this pilot study was to evaluate the safety and efficacy of the MagicTouch™ sirolimus-coated balloon (SCB) catheter (Concept Medical Inc., Tampa, FL, US) on improving the patency of failing arterio-venous fistulas (AVF) with de novo and recurrent stenoses. MATILDA reports early outcomes at 3- and 6 months post intervention.

Methods

Single-centre, single-arm prospective pilot study of 33 (18 males; mean age 64.7±11.6 years) end-stage renal failure Asian patients with a dysfunctional AVF, who underwent SCB angioplasty between May 2019-January 2020. All procedures were performed under local anaesthetic without sedation and as day surgery. All patients were prescribed dual antiplatelet therapy for 3 months and followed up with Duplex ultrasound at 3 and 6 months.

Results

47 stenotic target lesions treated and 24/33 (72.7%) patients were for restenosis. Main indications for intervention was low/dropping access flow (21/33; 63.6%) and most common target lesion was in the juxta-anastomosis (19/47; 40.4%). There was 100% technical and procedural success. There were no peri-procedural complications related to the SCB. The target lesion primary patency rates at 3 and 6 months were 46/47 (97.9%) and 29/35 (82.9%) respectively. Circuit access patency rates at 3 and 6 months were 31/33 (93.9%) and 17/25 (68%) respectively. There was one (2.9%) death at 6 months and 4/33 (12.1%) overall to date, all from patients’ underlying co-morbidities.

Conclusions

SCB angioplasty for dysfunctional AVF circuits is a safe and efficacious modality in Asian haemodialysis patients at six months comparable if not better than the paclitaxel data reported to date in the literature.

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)

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.

Helical stent (SUPERA™) and drug-coated balloon (Passeo-18 Lux™) for recurrent cephalic arch stenosis: Rationale and design of arch V SUPERA-LUX Study

BACKGROUND

The treatment options for cephalic arch stenosis are limited and standard of care remains at crossroads - none are ideal and there is currently no gold standard. Endovascular techniques are now the preferred primary therapeutic option because they are minimally invasive and better tolerated by haemodialysis patients who have multiple comorbidities. However, conventional plain old balloon angioplasty, bare metal stenting and stent grafts all have their limitations. The aim of this trial is to evaluate whether the helical SUPERA™ stent (Abbott Vascular, Santa Clara, CA, USA), which has a higher degree of flexibility and resistance to compressive forces compared to traditionally laser-cut nitinol stents, combined with a drug-coated balloon (Biotronik Passeo-18 Lux™) to minimize the neointimal hyperplasia effect, can improve patency and reduce reintervention rates.

METHODS AND RESULTS

Arch V SUPERA-LUX is a pilot investigator-initiated single-centre, single-arm prospective study. Twenty patients with a brachiocephalic fistula within 6 months of initial plain old balloon angioplasty for significant cephalic arch stenosis will be recruited for treatment with SUPERA and drug-coated balloon. The primary objectives are immediate angiographic and procedural success, primary patency and functional fistula at 1 week, 8 weeks, 6 and 12 months. The results from eight patients treated prospectively as proof of concept have shown primary patency of 83.3% at 1 year with 100% technical and procedural success rates. Enrolment for the Arch V SUPERA-LUX study is expected to be completed at the end of 2019.

CONCLUSION

The Arch V SUPERA-LUX study is the first trial to evaluate whether SUPERA stent implantation and drug-coated balloon use can provide superior protection against restenosis compared to traditional angioplasty, bare metal stents and stent grafts in recurrent cephalic arch stenosis. Initial pilot results are encouraging but longer follow-up is required to truly test this technique.

TRIAL REGISTRATION

This study is registered on ClinicalTrials.gov NCT03891693.