Perforator-sparing basilar artery reconstruction normalizes pathological hemodynamics in vertebrobasilar dolichoectasia: a CFD study.

Vertebrobasilar dolichoectasia (VBD) carries high risks of stroke and hemorrhage, yet current treatments remain suboptimal and often compromise critical pontine perforators (PPs). We used computational fluid dynamics (CFD) to evaluate a novel hemodynamically-guided, perforator-sparing reconstruction strategy. Patient-specific CFD models from 24 VBD patients were compared with 24 age-sex-matched controls and virtual post-intervention models simulating idealized partial anterior basilar artery (BA) lumen reduction to establish hemodynamic optimization targets while preserving posterior wall PPs. Transient simulations quantified pressure, velocity, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) within the BA and nine modeled PPs per case. Untreated VBD exhibited pathological hemodynamics: elevated aneurysmal pressure (101.73 ± 0.28 vs. 100.59 ± 0.87 mmHg, p < 0.001), flow stasis (velocity: 5.53 ± 3.52 vs. 12.41 ± 3.44 cm/s, p < 0.001), reduced TAWSS (0.007 ± 0.004 vs. 0.03 ± 0.01 Pa, p < 0.001), and increased OSI (0.07 ± 0.04 vs. 0.01 ± 0.00) and RRT (12.73 ± 13.81 vs. 0.33 ± 0.11 /Pa, all p < 0.001). Perforator hemodynamics remained comparable to controls. Virtual reconstruction of BA normalized all aneurysmal parameters toward physiological levels (Post vs. Pre: all p < 0.001) without adversely affecting hemodynamics in the modeled PPs under the assumptions of the CFD framework. Strong correlations existed between BA volume and adverse hemodynamics, with therapeutic benefits approaching saturation at about 250 mm3. This in silico study demonstrates that perforator-sparing partial reconstruction can normalize VBD's pathological hemodynamics without adversely affecting hemodynamics in the modeled PPs, and establishes a quantitative framework for future endovascular device development, though clinical translation requires validation through experimental models and prospective trials.