Blood flow changes in the transverse-sigmoid sinus junction following effective surgical reconstruction for unilateral pulsatile tinnitus with sigmoid sinus wall anomalies: a four-dimensional flow magnetic resonance imaging analysis.

Abstract

Background: Pulsatile tinnitus (PT) with sigmoid sinus wall anomalies (SSWAs) is often treated by surgical reconstruction. However, the effect of this surgical procedure on the PT-related blood flow is unclear. This study compared changes in the PT-related blood flow velocity and patterns in the transverse-sigmoid sinus junction (TSSJ) before and after surgical reconstruction using four-dimensional (4D) flow magnetic resonance imaging (MRI).

Methods: A retrospective study analyzed patients with unilateral pulse-synchronous PT confirmed to have ipsilateral SSWAs on preoperative CT, who underwent surgical reconstruction and had pre- and postoperative 4D flow MRI, with PT eliminated or significantly alleviated after at least 6 months of follow-up. Quantitative and qualitative data of the blood flow properties, including bilateral velocity, and the net flow upstream and downstream of the TSSJ, as well as vortices in the TSSJ, were obtained and compared before and after surgery.

Results: In total, 19 patients were included in the study, of whom, 6 had sigmoid sinus wall dehiscence (SSWD), and 13 had a diverticulum. Significant differences were only observed in the ipsilateral upstream average velocity (V_avg) in the SSWA group, and the contralateral downstream maximum velocity (V_max) in the SSWA group and diverticulum group before and after treatment (P=0.01, P=0.01, P=0.04, respectively). No significant changes were observed in the other quantitative indicators. Among the 19 patients, 17 had vortices on the surgical side before surgery; 8 showed vortex disappearance, and 9 showed a reduction in the vortex intensity after surgery. Vortices were observed in 11 of the 13 patients with diverticulum before surgery, but these disappeared or slowed after surgical intervention. The high-speed jet flow remained unchanged in 16 patients with transverse sinus stenosis (TSS) before and after treatment.

Conclusions: Surgical reconstruction does not appear to have a significant effect on PT-related blood flow properties, which suggests that this surgery is safe; however, the risk of ongoing recurrence remains.