PURPOSE: This study aimed to evaluate the prognostic value of thrombus stiffness, measured by strain elastography, in independently predicting the success of endovascular treatment for thrombosed hemodialysis fistulas. METHODS: The study employed a retrospective observational design. Forty-nine patients with chronic kidney disease undergoing hemodialysis and experiencing fistula dysfunction were included. Various factors were evaluated, including patient age, sex, comorbidities, arteriovenous fistula (AVF) type, use of antiplatelet agents, duration of thrombosed AVF dysfunction, thrombus length, thrombus stiffness, and thrombus strain ratio (SR). Thrombus stiffness was measured using strain ultrasound elastography. RESULTS: The presence of comorbidities (P=0.018), duration of AVF dysfunction due to thrombosis (P=0.005), thrombus stiffness (P<
0.001), and thrombus SR (P<
0.001) were statistically significant predictors of treatment success, while other factors were not. Thrombus stiffness and SR, assessed by two independent radiologists with excellent inter-reader agreement, demonstrated high reliability. The optimal SR cut-off for treatment success was 1.4 (sensitivity, 0.947
specificity, 0.901
area under the curve, 0.935). Multivariable logistic regression analysis revealed that both thrombus SR and thrombus stiffness significantly influenced treatment outcomes (P=0.003 and P=0.007, respectively). A 0.1-unit increase in thrombus SR was associated with 9.37% reduction in the likelihood of treatment success, while a smilar increase in thrombus stiffness exhibited an 8.06% reduction, underscoring their importance as prognostic factors in clinical setting. CONCLUSION: This study demonstrates the utility of strain ultrasound elastography in assessing thrombus stiffness in thrombosed hemodialysis AVFs and its correlation with treatment success.