Plain balloon first and drug-eluting balloon second? The role of DCBs in arteriovenous access

Kate Steiner (Stevenage, UK) discusses existing clinical evidence on drug-coated balloons (DCBs) in the treatment of arteriovenous access stenosis—and outlines areas where further data are still needed on how they stack up against more traditional plain-balloon techniques.

Failure of maturation in native autologous arteriovenous fistulas (AVFs), fistula thrombosis and dialysis access dysfunction are most often caused by arteriovenous access stenosis. Restenosis after percutaneous transluminal angioplasty (PTA) procedures occurs with patients often requiring repeat treatments to maintain functional patency, but strategies to increase primary patency rates post-PTA would improve outcomes for these patients. Whether DCBs should be a first-line treatment is dependent on there being enough evidence to advocate their use as such for the treatment of arteriovenous access stenosis.

The Kidney Disease Outcomes Quality Initiative (KDOQI) clinical practice guidelines for vascular access recommend a patient-individualised approach to the choice of balloon type for angioplasty based on the operator’s best clinical judgement and expertise.¹ They concluded there was insufficient evidence to make a recommendation regarding the use of DCBs in the primary treatment of AVF or arteriovenous graft (AVG) stenosis. A UK consensus approach for managing symptomatic AVF stenosis in haemodialysis patients published in 2021 came to the conclusion that, for stenoses recurring between three and 12 months, the group would have a lower threshold for using DCBs, but there was limited evidence to support their use as a first-line treatment.²

Since both of these publications, further trial data from multicentre randomised controlled trials (RCTs) have been presented and published, but whether this is sufficient to justify the use of DCBs as a first-line therapy remains to be seen. There are conflicting results seen in the trial data. The higher cost of DCBs is another factor and there has been concern about their safety profile since the US Food and Drug Administration (FDA) and UK Medicines and Healthcare products Regulatory Agency (MHRA) alerts regarding the use of drug-coated devices, and mortality data from their use in the treatment of peripheral vascular arterial disease.

The Lutonix investigational device exemption (IDE) clinical study (BD) was one of the first large RCTs examining the use of DCBs in arteriovenous access, and the two-year results demonstrated fewer interventions were needed to maintain target-lesion primary patency (TLPP) in the DCB group compared with plain-balloon angioplasty (PBA) at nine months where improvement in TLPP was statistically significantly higher.³ There were variable differences in patency rates between the groups at other timepoints within the study.

The IN.PACT AV Access clinical study (Medtronic), comparing DCB angioplasty with PBA, demonstrated that, at six months, TLPP was significantly higher within the DCB group at 82.2% compared with 59.5% within the standard PBA group.⁴ Trial data at 12 and 24 months have been presented, demonstrating sustained higher patency rates in the DCB group. The PAVE study was an investigator-led multicentre RCT, comparing the Lutonix DCB catheter with standard balloon angioplasty. The results were published in 2021, demonstrating a higher six-month primary patency rate for standard high-pressure balloon angioplasty at 84.5% compared with 71.7% in the DCB group.⁵

The studies to date demonstrate mixed results. The primary patency rates at six months for standard balloon angioplasty in the PAVE trial are similar to those seen for DCB angioplasty in the IN.PACT study. A key similarity of the trials is adequate vessel preparation with effective PBA prior to DCB use. None of the above trials have reported a statistically significant difference in mortality between the DCB and standard balloon angioplasty groups.

The KDOQI guidelines recommend a patient-individualised approach. It appears that some patients respond well to standard balloon angioplasty, while other patients will benefit from less frequent repeat interventions following DCB angioplasty. There are likely to be contributing variables that may fall into two groups: patient factors and lesion factors. Patient factors are unlikely to be demographic variables, which do not appear to be responsible for significant differences in outcome, but it may be that, in the future, biochemical or genetic markers are identified. Lesion factors include lesion location, de-novo versus restenotic lesions, and lesion morphology.

There does not appear to be sufficient evidence at present to advocate the primary use of DCBs for all patients and all lesions. It remains to be seen whether they are effective as first-line agents in all patients and in the treatment of multi-level disease.

References:

1. Lok C, Huber T S, Lee T, et al. KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update. AJKD. 2020; 75(4) Suppl2: 1–164.
2. Jaffer O, Gibbs P, Gibson M, et al. A UK Expert Consensus Approach for Managing Symptomatic Arteriovenous Fistula (AVF) Stenosis in Haemodialysis Patients. CVIR. 2021; 44(11): 1736–46.
3. Trerotola S, Saad T, Roy-Chaudhury P. The Lutonix AV randomised trial of paclitaxel-coated balloons in arteriovenous fistula stenosis: 2 year results and subgroup analysis. JVIR. 2020; 31(1): 1–14.
4. Lookstein R, Haruguchi H, Ouriel K, et al. Drug Coated balloons for dysfunctional arteriovenous fistulas. NEJM. 2020; 383: 733–42.
5. Karunanity N, Robinson E, Farhan A, et al. A multicenter randomized controlled trial indicates that paclitaxel-coated balloons provide no benefit for arteriovenous fistulas. Kidney International. 2021; 100: 447–56.

Kate Steiner is a consultant interventional radiologist, and the interventional radiology lead, at East and North Hertfordshire NHS Trust in Stevenage, UK. She has a subspeciality interest in vascular intervention and diagnostic vascular imaging, and in vascular ultrasound in particular. She is a Vascular Access Society of Britain and Ireland (VASBI) council member and maintains a research portfolio.

The author declared no relevant disclosures pertaining to this article.