The Role of High-Frequency Wall Vibrations in Adverse Vascular Remodeling of Arteriovenous Fistula for Hemodialysis

KEY POINTS: Flow-induced high-frequency vascular vibrations, computed through fluid-structure interaction simulations, are associated with fistula complications. The association between vibrations and arteriovenous fistula complications suggests a potential new mechanism responsible for vascular remodeling. The frequency and amplitude of vibrations are potential biomarkers for arteriovenous fistula surveillance. BACKGROUND: Despite progress in research, the mechanobiological mechanisms behind adverse vascular remodeling and failure in arteriovenous fistula (AVF) for hemodialysis remain unclear. The aim of this investigation was to assess the association between flow-induced vascular wall vibrations and adverse vascular remodeling in AVFs. METHODS: Six ESKD patients with native distal radio-cephalic AVF were monitored for 1 year with magnetic resonance imaging and Doppler ultrasound examinations. Patients were divided based on AVF outcomes: two maintained proper AVF patency and four developed complications (two venous stenoses and two excessive dilatations). Patient-specific fluid-structure interaction simulations were performed at different time points. RESULTS: Before vascular remodeling, stenotic AVFs exhibited two dominant frequency bands, between 45 and 100 Hz, while excessively dilated AVFs exhibited a single band at 50 Hz. Before the onset of remodeling, patients with complications exhibited significantly higher vibration amplitude (22.5±5.8 μ m versus 6.6±2.0 μ m, P < 0.01) and high-pass strain ([1.30±0.35] 10 -3 versus [0.30±0.10] 10 -3 , P < 0.01) than those with proper patency. Significant differences in vibration amplitude and high-pass strain were observed between patients with proper patency and those with stenosis ( P < 0.001 and P < 0.01, respectively), and in high-pass strain between patients with preserved patency and those with excessive dilatation ( P < 0.01). CONCLUSIONS: Specific vibration frequencies and amplitude levels appear to be associated with distinct types of vascular remodeling, indicating that they could potentially be biomarkers for AVF surveillance.