Randomized Controlled Study of Sirolimus-coated Balloons for Dysfunctional Hemodialysis Fistulas

<h2>Abstract</h2><h3>Introduction</h3> Restenosis following balloon angioplasty remains a major cause of arteriovenous fistula (AVF) dysfunction in patients receiving maintenance hemodialysis. We evaluated whether use of sirolimus-coated angioplasty balloons (SCB) improves access circuit primary patency (ACPP) in patients with dysfunctional, non-thrombosed AVFs. <h3>Methods</h3> This investigator-initiated, multicenter, single-blinded, randomized controlled trial (ClinicalTrials.gov identifier: NCT04409912) enrolled 170 patients from three tertiary teaching hospitals in Singapore. Patients with dysfunctional AVFs, including those with single or multiple stenotic lesions within the access circuit, were included. Following successful plain balloon angioplasty (<30% residual stenosis on digital subtraction angiography), patients were randomly assigned using a centralized web-based system to receive additional treatment with SCB (n=83) or placebo balloons (n=87). During the 12-month follow-up, patients and managing physicians were blinded. The proceduralists and coordinators could not be blinded because of visible differences between the balloons. The primary endpoint was ACPP during the first 6 months after the index procedure. Secondary endpoints included 12-month patency and safety outcomes. <h3>Results</h3> In both intention-to-treat and per-protocol analyses, 6-month ACPP was significantly higher in the SCB group compared with the placebo group (p=0.03). At 6 months, 70.1% (95% CI, 58.7–78.8) of patients treated with SCB remained patent, compared with 56.7% (95% CI, 45.5–66.4) in the placebo group. At 12 months, the difference in patency was not statistically significant in the intention-to-treat analysis (37.1% vs. 27.7%; p=0.07) but remained significant in the per-protocol analysis (36.4% vs. 25.2%; p=0.04). Adverse events were infrequent and no deaths occurred within 30 days in both groups. <h3>Conclusions</h3> Use of SCB following successful plain balloon angioplasty improved 6-month ACPP in patients with dysfunctional AVFs, including those with multiple stenotic lesions. Short-term safety findings were reassuring.