This study investigates the hemodynamic efficiency of endovascular coiling treatment for patient-specific middle cerebral artery (MCA) aneurysms, utilizing comprehensive computational models to analyze blood flow dynamics. Cerebral aneurysms, particularly those located within the MCA, carry significant risks of rupture, which can lead to severe neurological consequences. Endovascular coiling has surfaced as an effective, minimally invasive treatment option aimed at mitigating these risks by stabilizing the aneurysm wall and promoting thrombus formation.
Despite the widespread application of coiling, the relationship between the size of aneurysms and the efficacy of this treatment remains under-explored from the computational fluid dynamics (CFD) perspective. This study offers fresh insights by employing the Casson non-Newtonian model to simulate blood flow dynamics around both original and scaled-down geometries of MCA aneurysms.
The results reveal pivotal hemodynamic factors, such as wall shear stress (WSS) and oscillatory shear index (OSI), which were systematically analyzed to evaluate the effectiveness of coiling across varying aneurysm sizes. Key findings indicate coiling significantly reduces the risk of rupture, with larger aneurysm sac volumes showing more substantial decreases in high-risk hemodynamic zones.
For the study, the researchers employed CFD simulations, solving the Navier-Stokes equations for laminar, incompressible, and periodic blood flow. The simulations were illustrating the blood flow dynamics within the aneurysm, with the main comparison involving the original and scaled-down patient-specific MCA aneurysm models derived from the Aneurisk project.
A 67-year-old patient’s unruptured MCA aneurysm served as the model subject, and simulations were conducted applying realistic hemodynamic conditions, including hematocrit levels and blood flow rates variably between 3800 mg/s and 6600 mg/s. The findings emphasized how coiling is modeled as creating porous conditions inside the aneurysm sac, significantly affecting the wall shear stress profiles.
Assessments show the contour of WSS around the coiled aneurysms, comparing it with the uncoiled condition. The results illustrated coiling’s effectiveness at lowering shear stress on the aneurysm surface, potentially reducing the risks associated with rupture. Notably, the evaluation revealed high-pressure regions post-coiling, particularly evident in original models, underscoring the relevance of coiling, especially for larger Sac volumes.
The OSI, recognized as another significant parameter for evaluating rupture risks, displayed pronounced changes across the cardiac cycles modeled. The results suggested specific regions near the ostium are more susceptible to rupture than others, and interestingly, the application of coiling is demonstrated to effectively limit the land area at high risk.
Through detailed analysis, the study portrays not only the immediate effects of coiling on hemodynamic factors like pressure and shear stress but also emphasizes the longer-term implications for patient-specific treatment strategies. The insights provided reflect advancements as they can potentially aid surgeons and medical professionals toward more optimized intervention approaches for dealing with complex aneurysm cases, adjusting tactics depending on size and shape as well as the overall efficacy of coiling treatment.
Conclusively, the work showcases how computational evaluations of endovascular techniques can bridge knowledge gaps concerning aneurysm treatments. The investigational outcomes advocate for stronger integration of computational insights with clinical practices for enhancing treatment safety and efficacy as well as improving patient outcomes. The authors assert, “the use of coiling could efficiently decrease the shear stress on the surface of the sac,” highlighting the relevance of employing such advanced techniques for cerebral aneurysm treatments.