Computational Fluid Dynamics for Predicting Delayed Cerebral Ischemia after Subarachnoid Hemorrhage

Background and purpose: Delayed cerebral ischemia (DCI) is a significant cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (SAH). Recently, we reported the various hemodynamic characteristics of ruptured aneurysm with computational fluid dynamics (CFD). The aim of this study was to assess whether CFD was useful to predict the development of DCI after SAH. Materials and methods: This was a single-center, retrospective, observational study. We investigated 53 consecutive patients with SAH. CFD was analyzed by subtraction 3-dimentional computed tomography angiography performed within 72 hours after onset. Results: Six of 53 patients (11.3%) had DCI. There were no significant differences in age, SAH grades at admission, amount of subarachnoid or intraventricular blood, aneurysm location and treatment modalities (clipping or coiling) between patients with and without DCI. Concerning the CFD analysis, the areas of extracranial ICA and distal parent artery were tended to be smaller (14.1 mm3 vs 18.0 mm3, 3.58 mm3 vs 4.67 mm3, respectively), and the flow velocity in distal parent artery also tended to be higher (0.640 m/s vs 0.469 m/s) in patients with DCI than without DCI, but there were no significant differences. Conclusions: This study first describes the possibility of CFD analysis to predict the subsequent development of DCI after SAH. CFD analysis may be useful to predict the DCI in SAH patients, because it is possible to detect the slight differences described above on CT angiography data obtained at admission.