Effects of Different Degrees of Extraluminal Compression on Hemodynamics in a Prominent Transverse-Sigmoid Sinus Junction.

Objectives: To simulate hemodynamic changes after extraluminal compression in pulsatile tinnitus (PT) patients with a prominent transverse-sigmoid sinus junction (PTSJ). Methods: One patient-specific case was reconstructed based on computed tomography venography (CTV) images of a PT patient. The compression degree served as a new index in this study. Cases with 10, 20, 30, 40, 50, 60, 70, 80, and 90% of the compression degree of the control subject were constructed. Steady-state computational fluid dynamics (CFD) were assessed. The wall pressure distribution, wall maximum pressure (P _max ) and flow pattern (velocity streamlines and velocity vector) of the PTSJ were calculated to evaluate hemodynamic differences among all cases. Results: With increasing compression, the wall pressure at the compression point and downstream of the PTSJ decreased but increased upstream. When the compression degree exceeded 70%, the upstream pressure increased significantly. Above 50% compression, the blood flow pattern downstream of the sigmoid sinus tended to spiral, especially after 80% compression. Beyond 60% compression, the blood flow pattern under the compression axis became more medial. Conclusion: Mechanical compression of PTSJ changes wall pressure and blood flow patterns. The degree of compression should be carefully observed to avoid possible complications or reoccurrence. [ABSTRACT FROM AUTHOR]