A first-time presentation at the 2024 Charing Cross (CX) International Symposium (23–25 April, London, UK) of five-year data from the IN.PACT AV Access study evaluating the IN.PACT AV (Medtronic) drug-coated balloon (DCB) led principal investigator and CX co-chair Andrew Holden (Auckland, New Zealand) to conclude that “we know which DCB to use” now. However, discussions during the CX Vascular Access Masterclass did raise several other questions that are yet to be answered conclusively.
With IN.PACT AV Access having demonstrated superior outcomes at three years with the IN.PACT AV DCB versus plain balloon angioplasty for dialysis access—as per a presentation from Holden at last year’s CX Symposium—the speaker initially noted that it is currently the only randomised pivotal study to have produced “consistent and sustained clinical benefit” with an arteriovenous fistula (AVF) treatment device at such a long-term follow-up.
According to Holden, 98 patients—57 in the DCB group and 41 in the standard percutaneous transluminal angioplasty (PTA) group—had follow-up data available at five years. He reported an all-cause mortality rate (post vital status update) of 41% and 46.5%, respectively, across these two groups, describing these figures as “comparable”. Holden highlighted the fact that both of these figures are significantly lower than a 60.4% five-year mortality rate among US haemodialysis patients derived from the United States Renal Data System (USRDS).
“Durable, long-term data suggest the use of IN.PACT AV DCB as a standard of care for AVF maintenance in patients with ESKD [end-stage kidney disease],” Holden concluded, also remarking that “we now know which DCB to use”, and reporting that the device is enabling prolonged time to reintervention in dialysis access patients.
These findings may—in Holden’s view, at least—have drawn a line under debates over the optimal DCB in dialysis intervention, but further discussions throughout the Vascular Access Masterclass revealed several other areas yet to be fully addressed. The first of two controversies tackled within the session alluded to the fact that, despite recommendations in the 2019 update to the Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline for Vascular Access, ‘we don’t know what the right access, at the right time, for the right patient, is’.
Presentations here saw Maarten Snoeijs (Maastricht University, Maastricht, The Netherlands) assert that “access registries are not adequate, currently”; Karen Stevenson (University of Glasgow, Glasgow, UK) highlight the need for ‘minimally disruptive vascular access’ owing to the immense burden experienced by dialysis patients; and David Kingsmore (University of Glasgow, Glasgow, UK) advocate arteriovenous grafts (AVGs) over AVFs, drawing dissent from Robert Shahverdyan (Asklepios Klinik Barmbek, Hamburg, Germany). A somewhat more positive outlook was conveyed via a presentation from Koen van der Bogt (Leiden University Medical Centre, Leiden, The Netherlands), who updated delegates on progress towards developing a ‘dynamic AVF’ that is able to normalise flow rates between dialysis sessions, thus reducing patients’ cardiac burden. While this project remains in its infancy, CX Executive Board member Nicholas Inston (Queen Elizabeth Hospital Birmingham, Birmingham, UK) described the concept as “really innovative and futuristic”.
Following this, speakers debated a highly contentious notion: ‘endoAVFs are a failed experiment’. Tobias Steinke (Schön Klinik, Dusseldorf, Germany) and Shannon Thomas (Prince of Wales Hospital, Sydney, Australia) delivered arguments favouring this statement, with the former emphasising that device-created fistulas have demonstrated some success in specialised centres but these results are unlikely to be replicable in the ‘real world’, and the latter positing that better surgical fistulas—not endoAVFs—hold the key to truly solving existing vascular access challenges.
Meanwhile, Shahverdyan and Monnie Wasse (Rush University Medical Center, Chicago, USA) were in opposition to these viewpoints, with both primarily focusing their arguments on positive data produced on the Ellipsys (Medtronic) and WavelinQ (BD) systems. Shahverdyan also noted that endoAVFs are “a complementary addition, not a replacement” for surgical fistulas. Wasse pointed to the high technical success rates observed with endoAVFs, also averring that they are already part of the current standard of care and should now be incorporated into clinical guidelines.
Both sides garnered considerable support, but pro-endoAVF arguments accrued marginally more support, with an audience poll revealing that 54% of those in attendance disagreed with the suggestion that endovascular fistulas are a ‘failed experiment’. CX Executive Board member Kate Steiner (East and North Herts NHS Trust, Stevenage, UK) weighed in on these discussions, noting that “it would be impossible to take [endoAVFs] away now”—especially given the number of patients she sees who would not be able to receive a fistula if only surgical options were available. Inston dubbed the session and voting result as “fascinating”, predicting that such debates are likely to rage on for several years.
