Quantifying the early recoil of post-angioplasty lesions in the native arterio-venous fistula

Background: Despite technically successful angioplasty of native arteriovenous fistula (AVF) stenoses, early luminal loss may occur before routine post-angiography surveillance. While elastic recoil is recognized intra-procedurally, delayed reduction in luminal diameter from early post-angioplasty recoil (EPR) remains poorly characterized. Methods: We performed a retrospective secondary analysis of a multicenter randomized controlled trial comparing drug-eluting balloons (DEB) with sham balloons for recurrent AVF stenoses in 102 patients. Minimum luminal diameter on completion angiography (D0) was compared with the first post-angioplasty ultrasound performed within 14 days (D1). EPR was defined as >30% reduction in luminal diameter between D0 and D1. Baseline clinical, vascular access, and procedural variables were analyzed to identify predictors of EPR. Re-intervention rates and luminal changes at 6 months were assessed. Results: Of 129 trial participants, 102 had complete angiographic and ultrasound datasets. EPR occurred in 42 patients (41%), with a mean diameter reduction of 43.7%. AVFs demonstrating EPR were significantly older than those without recoil (mean age 3.71 vs 2.33 years; p = 0.022). Patient age, access location, prior interventions, and stent use were not associated with EPR. Mean diameter reduction was 43.7% in the EPR group versus 11.5% in the non-EPR group (p < 0.001). Overall 6-month re-intervention rates were similar between groups; however, subgroup analysis demonstrated that EPR accounted for approximately 45% of total luminal loss in 27/102 patients requiring repeat intervention. DEB use did not influence EPR but was associated with reduced late restenosis. Conclusions: Early post-angioplasty luminal loss detected on ultrasound is common following AVF angioplasty and occurs more frequently in older fistulas. EPR contributes substantially to subsequent restenosis and may represent an under-recognized mechanism of early treatment failure. Selective early ultrasound surveillance may help identify patients at increased risk of early luminal compromise.