Longitudinal ultrasonographic assessment of external vessel preservation by drug-coated balloon in juxta-anastomotic AVF stenosis

BACKGROUND: Juxta-anastomotic stenosis is a major cause of arteriovenous fistula (AVF) dysfunction. Although drug-coated balloons (DCB) have demonstrated clinical benefit, the associated morphological changes compared with plain old balloon angioplasty (POBA) remain poorly defined. This study aimed to characterize vascular remodeling patterns after DCB and POBA using ultrasonographic cross-sectional area (CSA) analysis. METHODS: In 41 patients with juxta-anastomotic AVF stenosis, all initially underwent POBA and subsequently DCB for recurrent stenosis. Luminal cross-sectional area (L‑CSA), external vessel cross-sectional area (E‑CSA), and vessel wall area (VWA) were assessed pre-treatment, post-treatment, and at 3 months. Longitudinal mixed-effects and baseline-adjusted models evaluated remodeling patterns and independent treatment effects. Exploratory intima-media thickness (IMT) analysis was performed. RESULTS: Median target lesion primary patency (TLPP) was longer after DCB than POBA (10.8 vs 3.3 months). At 3 months, L‑CSA and E‑CSA were significantly larger after DCB, whereas VWA did not differ between treatments. Longitudinal mixed-effects models showed significant treatment-by-time interactions for L‑CSA and E‑CSA, with progressive luminal narrowing and external vessel shrinkage after POBA that were attenuated after DCB, while VWA increased similarly in both groups. Baseline-adjusted models confirmed that DCB was independently associated with larger 3-month L‑CSA and E‑CSA suggesting that the patency benefit observed after DCB was associated with preservation of external vessel dimensions rather than suppression of wall thickening. Exploratory analyses further showed that, despite similar changes in IMT area, IMT thickness increased more slowly after DCB, suggesting a possible contribution to sustained E‑CSA preservation. CONCLUSION: DCB provided improved clinical outcomes in juxta-anastomotic stenosis. These findings suggest that improved outcomes after DCB may be associated with preservation of external vessel architecture and mitigation of constrictive remodeling, potentially supported by IMT suppression, rather than a predominant inhibitory effect on wall thickening. This suggests a site-specific mechanism of DCB action in the hemodynamically stressed juxta-anastomotic segment.