Multiphysics coupling numerical simulation of flow-diverting stents in the treatment of patients with pulsatile tinnitus

Patients with pulsatile tinnitus (PT) have unstable treatment effects after resurfacing surgery. Flow-diverting stents (FDS) are proposed as a potential method for the treatment of PT, but the therapeutic effect is not clear. This study aimed to investigate the efficacy of FDS in the treatment of patients with PT induced by sigmoid sinus diverticulum (SSD) and sigmoid sinus wall dehiscence (SSWD). In addition, we aimed to explore the treatment mechanism of PT. Transient-state multiphysics coupling numerical simulation method based on computed tomography angiography of five patients was used to clarify the biomechanical and acoustic states before and after FDS placement. FDS was placed to prevent the blood flow from impacting the vessel wall in the SSD and SSWD areas. Low blood flow velocity (<0.0391 m/s), high relative residence time (>10 Pa-1), and low wall shear stress of SSD might lead to thrombosis after FDS placement. The average pressure on the SSWD area of each patient decreased by 13.77%, 18.82%, 29.23%, 19.03%, and 11.20%. The average displacement of the vessel wall on the SSWD area showed acute pulsation and decreased by 15.29%, 14.64%, 30.22%, 41.03%, and 21.28%. The average sound pressure level at the tympanum decreased by 14.01%, 9.33%, 17.66%, 18.88%, and 25.18%, respectively. In brief, FDS was placed to avoid blood flow impacting vessels and reduce the vibration of vessels in the short term, thereby attenuating the degree of PT. The long-term prognosis was that the SSWD area was blocked after SSD thrombosis. Therefore, FDS might be an effective method for the treatment of PT induced by SSD and SSWD. This study would provide a theoretical basis for the treatment of PT and an exploration of FDS design in the treatment of PT.