Hemodynamics study on the relationship between the sigmoid sinus wall dehiscence and the blood flow pattern of the transverse sinus and sigmoid sinus junction

Sigmoid sinus wall dehiscence (SSWD) is a common pathophysiology of patients with pulsatile tinnitus (PT). However, the pathological mechanism of SSWD is unclear. This study aimed to investigate the relationship between the position of the SSWD and blood flow pattern of the transverse sinus and sigmoid sinus (TS-SS) junction. The impact of the blood flow was hypothesized to be the pathological mechanism of SSWD. Twenty patients and two healthy volunteers were analyzed retrospectively, and transient computer fluid dynamics was used to verify this hypothesis. A 4D flow magnetic resonance imaging experiment was performed to validate the numerical simulation. The position of high-velocity blood flow impacting the vessel wall (17/20) was consistent with SSWD. In healthy volunteers, the temporal bone was thin where the blood flow impacted the blood vessel wall. The average wall shear stress (20/20) and pressure (18/20) of the SSWD area (peak) were higher than those of sigmoid sinus wall anomalies (the contact area between the vessel wall and the temporal bone at the TS-SS junction). The average wall pressure percentage differences of 16/20, 11/20, and 4/20 patients were more than 5%, 10%, and 20%, respectively. The average wall shear stress percentage differences of 20/20, 18/20, and 16/ 20 patients were more than 5%, 10%, and 20%, respectively. In brief, the blood flow of the TS-SS junction impacted the vessel wall and increased wall pressure, which might be an important pathological mechanism of SSWD. This study could serve as a basis for the diagnosis and SSWD resurfacing surgery of patients with PT induced by SSWD.

Automated summary

This study investigated the relationship between the position of sigmoid sinus wall dehiscence (SSWD) and the blood flow pattern at the junction of the transverse sinus and sigmoid sinus (TS-SS). It was found that the location of high-velocity blood flow impacting the vessel wall was consistent with SSWD, and the temporal bone was thinner in healthy volunteers where the blood flow impacted the vessel wall. The study also revealed higher wall shear stress and pressure in the SSWD area. Therefore, the impact of blood flow may be an important pathological mechanism of SSWD.