The second day of the 2023 meeting of the American Society of Diagnostic and Interventional Nephrology (ASDIN; 17–19 February, Orlando, USA) played host to a packed afternoon session on new technologies for interventional nephrology. Amidst this came a presentation from Daniel Patel (Volusia Flagler Vascular Center, Daytona Beach, USA) on drug-coated balloon (DCB) use in arteriovenous fistula (AVF) stenosis.
Patel launched into a discussion of plain balloon and DCB angioplasty, noting that the former has a primary patency rate of only 50% after six months according to a 2019 systematic meta-analysis led by Ian Jun Yan Wee (National University of Singapore, Singapore). “Is there a better way to do what we do?” he asked. “Is there a physiological way rather than a mechanical way that we can get a better outcome here?”
Moving to focus on paclitaxel, he raised results from a study into its use with the Lutonix (BD) balloon published in 2018 in the Clinical Journal of the American Society of Nephrology (CJASN). This study, by Scott Trerotola (Perelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania) et al, found that DCB angioplasty was equivalent in terms of safety with plain-balloon, but that it “did not meet the primary effectiveness end point at 180 days compared with conventional angioplasty”. It demonstrated no “no difference in access circuit patency” as well as “no lesion-specific benefit of DCB”.
Patel said “the story is not completely over for Lutonix”, drawing attention to the ABISS trial underway in France that has suggested “some improvement in Lutonix outcomes”, but that there was not yet meaningful data from this study to analyse. He also posed the question of whether paclitaxel-based DCBs could demonstrate better primary patency rates with higher doses.. Initial concerns regarding risk of mortality with Paclitaxel doses have not been demonstrated multiple DCB dialysis access studies, Patel argued. More recent studies, he said, are beginning to examine the effects on animal models of higher doses of the drug in angioplasty than have previously been tried, up to 6μg compared to the 3–4μg of previous studies. These include a 2021 investigation by Ole Gemeinhardt (Humboldt-Universität zu Berlin, Berlin, Germany) et al.
The IN.PACT Arteriovenous (AV) Access IDE study, published in The New England Journal of Medicine (NEJM) and carried out by Robert A Lookstein (Ichan School of Medicine at Mount Sinai, New York City, New York) et al, did also find that DCB was superior to plain-balloon angioplasty “for the treatment of stenotic lesions in dysfunctional haemodialysis arteriovenous fistulas during the 6 months after the procedure”. Its three-year data has also shown the benefits of “reduced interventions” while also demonstrating “improved patency” and “potential for cost savings” in comparison to treatment with plain balloon angioplasty.
Sirolimus was also addressed in the course of Patel’s talk. Describing it as “effective in preventing arterial re-stenosis”, he cited the MATILDA trial published in the European Journal of Vascular and Endovascular Surgery (ESVS) and the ISABELLA trial cited in Journal of Vascular Access (JVA). These prospective studies signalled efficacy of Sirolimus in treating dialysis access stenosis, Patel suggested, though he also noted that further studies are ongoing.
Finally, Patel asked: “are we there yet?” There remain many unanswered questions on DCBs, he argued, including particularly the advantages of a higher dose of paclitaxel. He also questioned whether “cutting balloon vessel prep” and employing larger-diameter balloons may have a beneficial effect. Comparison of DCBs with stent grafts are also due, he said, as was further investigation into where exactly DCB technology works best—whether that is in central veins, immature AV fistulae, AV graft stenosis or elsewhere. All of these, he said, were critical questions to be answered with the help of future studies. Finally, in review of the evidence, he said the data from the IN.PACT AV study were “compelling”, while DCBs appeared to be “ideal for poor stent areas” like cannulation zones and vessel junctions. Concluding, he said there was significant potential for DCB technology to transform the management of haemodialysis patients.