Shear Wave Elastography in AV Fistula Thrombosis: Differentiating Thrombus Age and Assessing Clinical Outcomes of Balloon Angioplasty.

Objectives: To evaluate the role of shear wave elastography (SWE) in distinguishing acute from subacute thrombi in thrombosed arteriovenous fistulas (AVFs) and explore the relationship between thrombus stiffness and outcomes of balloon angioplasty.

Materials and methods: This retrospective study included 44 dialysis patients with thrombosed AVFs from June 2022 to June 2024. Patients underwent Doppler ultrasound and SWE to assess thrombus age, followed by balloon angioplasty. Based on ultrasound findings and clinical history, patients were classified into acute and subacute thrombus groups. SWE was used to measure thrombus stiffness (kPa values). Procedural outcomes, including technical and clinical success, and primary and secondary patency, were compared between groups.

Results: The study included 23 patients with acute and 21 with subacute thrombus. SWE measurements (average, median, and maximum kPa) were significantly higher in subacute thrombi (P < .001). A strong positive correlation existed between thrombus age and kPa values (r = .770, r = .727, r = .835). Receiver operating characteristic analysis showed SWE could effectively distinguish acute from subacute thrombi, with an average cut-off of 31.733 kPa (sensitivity: 90.5%, specificity: 73.9%). No significant correlation was found between SWE values and procedural outcomes (P > .05).

Conclusion: SWE is a promising tool for assessing thrombus age in AVF thrombosis, effectively differentiating between acute and subacute thrombi. Although it did not predict procedural success, SWE could complement existing imaging for improved thrombus characterization and treatment planning.