Statins are not associated with short-term improved aneurysm healing in a rabbit model of unruptured aneurysms

Background Owing to their anti-inflammatory effects and ability to stimulate production of extracellular matrix and chemotactic migration of mesenchymal progenitor cells, statins could potentially improve aneurysm healing after endovascular treatment. Objective To test the hypothesis that systemic administration of simvastatin would improve aneurysm healing in a rabbit model of unruptured intracranial aneurysms. Methods Experimental aneurysms were created in female rabbits and were embolized with platinum coils. Six rabbits served as controls and six rabbits received oral administration of simvastatin. Digital subtraction angiography was used to evaluate stability after embolization. Subjects were euthanized 4 weeks after coil embolization. Histologic samples were examined with a grading system (0-12) based on neck and dome features. Aneurysm occlusion data were compared using a Student t test. Results No significant differences in the mean aneurysm size were found between groups. No coil compaction occurred in either group. All aneurysms in both the statin and control groups showed stable occlusion. There were no significant differences in the histologic grade of occlusion in either group (statin group 2.6±0.8 vs control group 2.7±3.2, p=0.94). Conclusions Systemic statin administration after platinum coil embolization of unruptured aneurysms in a rabbit model does not improve aneurysm occlusion rates at 4 weeks.