横窦狭窄合并颈静脉球高位对乙状窦血管血流动力学影响的数值模拟

Numerical simulation of the effect of transverse sinus stenosis with high jugular bulb on hemodynamics of sigmoid sinus vessels

目的探讨横窦狭窄(transverse sinus stenosis,TSS)合并颈静脉球高位(high-riding jugular bulbs,HJB)对乙状窦(sigmoid sinus,SS)血管血流动力学的影响,为横窦狭窄合并颈静脉球高位导致的搏动性耳鸣(pulsatile tinnitus,PT)治疗提供理论依据。方法基于具有横窦狭窄和颈静脉球高位的搏动性耳鸣患者,利用三维建模软件Freeform,建立横窦狭窄程度0%、25%、50%和75%,球高度0 cm、0.5 cm和1.0 cm的血管模型;利用流体动力学虚拟仿真分析软件,对血管中的瞬态流动进行数值模拟,入口施加瞬态流速,出口施加恒定压力;计算后得到血管的压力和涡量等参数,进而分析横窦狭窄合并颈静脉球高位对乙状窦血管的血流动力学影响。结果在相同的横窦狭窄程度下,颈静脉球高度的变化对乙状窦壁异常区域(sigmoid sinus wall anomalies,SSWA)的时间平均壁面压力(TAP_(avg))影响较大,而对SS处的时间平均体积涡量(TAV_(avg)V)影响不明显。在相同的颈静脉球高度下,横窦狭窄程度的加深,对SSWA区域的TAP_(avg)和SS处的TAV_(avg)V均有明显的影响。结论当横窦狭窄与颈静脉球高位同时存在时,横窦狭窄对乙状窦血管血流动力学的影响显著,横窦狭窄可能是导致耳鸣的主要原因。颈静脉球高位的存在会增大SSWA区域的壁面压力,乙状窦骨壁缺失可能是由高速血流长期冲击而成。

Objective To explore the effect of transverse sinus stenosis(TSS)combined with high jugular bulb(HJB)on sigmoid sinus(SS)and to provide a theoretical basis for the treatment of pulsating tinnitus caused by transverse sinus stenosis combined with high jugular bulb.Methods Based on patients with pulsating(PT)tinnitus with transverse sinus stenosis and jugular bulbous height,3D modeling software Freeform was used to establish vascular models with transverse sinus stenosis degree of 0%,25%,50%and 75%,and bulbous height of 0cm,0.5 cm and 1.0 cm.The transient flow in the blood vessel was numerically simulated by using the virtual simulation software of fluid dynamics.The transient flow rate was applied at the inlet and constant pressure was applied at the outlet.After calculation,parameters such as pressure and vorticity of vessels were obtained,and then the hemodynamic effect of transverse sinus stenosis combined with high jugular bulb on sigmoid sinus vessels was analyzed.Results At the same degree of transverse sinus stenosis,the change of jugular bulb height had a greater impact on TAP_(avg) in sigmoid sinus wall anomalies(SSWA)region,but had no significant impact on TAV_(avg)V in SS.At the same jugular bulb height,the deepening of transverse sinus stenosis had significant effects on TAP_(avg) in the SSWA region and TAV_(avg)V in the SS.Conclusions When transverse sinus stenosis and high jugular bulb exist together,the effect of transverse sinus stenosis on the hemodynamics of sigmoid sinus vessels is significant,and transverse sinus stenosis may be the main cause of tinnitus.The presence of high jugular bulb will increase the wall pressure in the SSWA region,and sigmoid sinus wall dehiscence may be caused by the long-term impact of high-speed blood flow.