RESUMEN
The aim of our study was to identify risk factors for recanalization 6 months after coil embolization using clinical data followed by computational fluid dynamics (CFD) analysis. METHODS: Firstly, clinical data of 184 patients treated with coil embolization were analyzed retrospectively. Secondly, aneurysm models for high/low recanalization risk were generated based on ROC curves and their cut-off points. Afterward, CFD was utilized to validate the results. RESULTS: In multivariable analysis, aneurysm filling during the first embolization was an independent risk factor whilst packing density was a protective factor of recanalization after 6 months in patients with aSAH. For patients with unruptured aneurysms, packing density was found to be a protective factor whilst the aneurysm neck size was an independent risk factor. Complex flow pattern and multiple vortices were associated with aneurysm shape and were characteristic of the high recanalization risk group. CONCLUSIONS: Statistical analysis suggested that there are various factors influencing recanalization risk. Once certain values of morphometric parameters are exceeded, a complex flow with numerous vortices occurs. This phenomenon was revealed due to CFD investigations that validated our statistical research. Thus, the complex flow pattern itself can be treated as a relevant recanalization predictor.
RESUMEN
BACKGROUND: The objective of our project was to identify a late recanalization predictor in ruptured intracranial aneurysms treated with coil embolization. This goal was achieved by means of a statistical analysis followed by a computational fluid dynamics (CFD) with porous media modelling approach. Porous media CFD simulated the hemodynamics within the aneurysmal dome after coiling. METHODS: Firstly, a retrospective single center analysis of 66 aneurysmal subarachnoid hemorrhage patients was conducted. The authors assessed morphometric parameters, packing density, first coil volume packing density (1st VPD) and recanalization rate on digital subtraction angiograms (DSA). The effectiveness of initial endovascular treatment was visually determined using the modified Raymond-Roy classification directly after the embolization and in a 6- and 12-month follow-up DSA. In the next step, a comparison between porous media CFD analyses and our statistical results was performed. A geometry used during numerical simulations based on a patient-specific anatomy, where the aneurysm dome was modelled as a separate, porous domain. To evaluate hemodynamic changes, CFD was utilized for a control case (without any porosity) and for a wide range of porosities that resembled 1-30% of VPD. Numerical analyses were performed in Ansys CFX solver. RESULTS: A multivariate analysis showed that 1st VPD affected the late recanalization rate (p < 0.001). Its value was significantly greater in all patients without recanalization (p < 0.001). Receiver operating characteristic curves governed by the univariate analysis showed that the model for late recanalization prediction based on 1st VPD (AUC 0.94 (95%CI: 0.86-1.00) is the most important predictor of late recanalization (p < 0.001). A cut-off point of 10.56% (sensitivity-0.722; specificity-0.979) was confirmed as optimal in a computational fluid dynamics analysis. The CFD results indicate that pressure at the aneurysm wall and residual flow volume (blood volume with mean fluid velocity > 0.01 m/s) within the aneurysmal dome tended to asymptotically decrease when VPD exceeded 10%. CONCLUSIONS: High 1st VPD decreases the late recanalization rate in ruptured intracranial aneurysms treated with coil embolization (according to our statistical results > 10.56%). We present an easy intraoperatively calculable predictor which has the potential to be used in clinical practice as a tip to improve clinical outcomes.
RESUMEN
OBJECTIVE: Traumatic brain injury (TBI) remains a major cause of morbidity and mortality worldwide. The prognostic value of skull fracture (SF) remains to be clearly defined. To evaluate the need for neurosurgical intervention and determine the risk factors of conservative treatment failure (CTF), we retrieved from the hospital database the records of patients with SF after TBI. METHODS: We analyzed 146 consecutive patients (mean age: 49.8 ± 17.5 years) treated at the department of neurosurgery in a 5-year period. Clinical data, radiologic reports, and laboratory results were evaluated retrospectively. RESULTS: A total of 63% of patients were treated conservatively, 21.9% were operated on immediately, and 15.1% experienced CTF. Overall, 73.3% had a favorable outcome; the mortality rate was 13%. Intracranial bleeding occurred in 96.6% of cases, basilar SF in 61%, and cerebrospinal fluid (CSF) leak in 2.8%. The independent risk factors for outcome were Glasgow Coma Scale (GCS) score, age, and platelet count (PCT). The independent risk factors for CTF were epidural hematoma, subdural hematoma, mass effect, edema, international normalized ratio, PCT, mean platelet volume, and CSF leakage. The consensus decision tree algorithm used at the accident and emergency department indicated patients with no need for neurosurgical intervention with an accuracy of 91.7%, sensitivity of 88.9%, and featured the importance of mass effect, GCS, and epidural hematoma. CONCLUSIONS: Tests included in the complete blood count appeared useful for predicting the course in patients with SF, although the most important factors were age and neurologic status, as well as radiologic findings. Our decision tree requires further validation before it can be used in everyday practice.
