Covered stents vs. balloon angioplasty for dysfunctional arteriovenous fistulas and grafts in hemodialysis: a systematic review and meta-analysis

To evaluate the added clinical value of covered stents following vessel preparation compared to percutaneous transluminal angioplasty (PTA) alone for dysfunctional hemodialysis arteriovenous fistulas (AVFs) and grafts (AVGs). PubMed, EMBASE, and the Cochrane Library were searched from inception to October 2025. Randomized controlled trials (RCTs) comparing covered stent placement vs. PTA alone in adult patients with AV access stenosis were included. Two independent reviewers extracted data and assessed the risk of bias. Random-effects meta-analyses and prespecified subgroup evaluations by access type were performed. Six RCTs comprising 1121 patients met the inclusion criteria. Compared with PTA alone, covered stents significantly improved target-lesion primary patency at 6 months (OR=3.97, 95% CI 2.08–7.59), 12 months (OR=4.17, 95% CI 2.50–6.95), and 24 months (OR=3.44, 95% CI 1.50–7.88). Access circuit primary patency (ACPP) was significantly higher for stents at 6 months (OR=1.96, 95% CI 1.11–3.44), but lost statistical significance at 12 and 24 months. Procedural success was significantly higher in the covered stent group (OR=2.03, 95% CI 1.01–4.09). Subgroup analyses demonstrated statistically significant 6-month primary patency benefits within both AVF and AVG cohorts (interaction p = 0.11). Covered stents offer superior immediate procedural success and long-term target-lesion patency compared with PTA alone, with the most robust evidence observed in AVG populations. However, their broader protective effect on the overall access circuit is time-bound, and clinicians must carefully weigh this benefit against potential device-related complications. Future RCTs should prioritize exact anatomical site-stratification and larger AVF cohorts to better define optimal patient selection.