Hemodynamic changes during simulation of sub-maximal handgrip maneuver in small basilar tip aneurysms: A...

Evaluate through computational fluid dynamics (CFD) and fluid structure interaction (FSI) simulations basilar tip aneurysms (BTAs) hemodynamics at rest and during early (PLT1) and late (PLT2) phases of a sub-maximal handgrip (HG) maneuver.

Vascular segmentation used 3D rotational angiograms, and meshes were generated for accurate simulation. Time-averaged wall shear stress (TAWSS) at the aneurysm/parent vessel, oscillatory shear index (OSI), relative residence time (RRT), low and high shear stress area ratio (LSAR/HSAR), and wall deformation metrics (Von Mises stress, wall displacement, and strain) were calculated and compared.

Seven patients (mean age: 60 ± 4.3 years; mean aneurysm size: 5.00 ± 1.76 mm) were included. 3 aneurysms were irregular, and 2 were ruptured. Ruptured BTAs were smaller (3.58 vs. 5.56 mm; p = 0.2009), had higher RRT (0.66 vs. 0.43 m²/N; p = 0.0276) and LSAR (5.11 % vs. 0 %; p = 0.0326). In unruptured BTAs, HG increased TAWSS (PLT1 +28.4 %, p = 0.0002; PLT2: +23.9 %, p = 0.0002), reduced RRT (PLT1 -21.7 %, p = 0.0009; PLT2: -18.6 %; p = 0.0016), increased HSAR (PLT1 +82.1 %, p = 0.0431, PLT2 +68.9 %, p = 0.0431), increased peak von Mises stress (PLT1 +18.6 %, p = 0.0223, PLT2 +31.9 %; p = 0.0087), maximum wall displacement (PLT1 +8.0 %, p = 0.0431; PLT2 +12.8 %, p = 0.0431) and maximum strain (PLT1 +7.13 %, p = 0.0201; PLT2 +11.8 %, p = 0.0043). Ruptured aneurysms showed similar trends with higher TAWSSR increases (PLT1 +31.6 %, p = 0.0225; PLT2 +28.2 %, p = 0.0391) and larger reductions in RRT (PLT1 -24.4 %, p = 0.0178; PLT2 -23.8 %, p = 0.0411).

In unruptured BTAs, PLT1 produced the greatest TAWSS increase and RRT reduction, whereas PLT2 led to maximal wall deformation. Ruptured aneurysms demonstrated greater TAWSSR increases and RRT reductions during simulation.