The purpose of this study is to evaluate the long-term stability of embolized aneurysms using the volume embolization rate (VER). One hundred and six aneurysms in 96 patients who were treated with Guglielmi detachable coils were selected for this study. Follow-up angiography was performed at six or more months after initial treatment. Every aneurysm was packed as densely as possible, however, the percentage of stability varied according to the size of the aneurysm or the size of the aneurysm neck. The percentage of stable aneurysm was 82% (56/68) in small aneurysms with small necks, 68% (13/19) in small aneurysms with wide necks and 42% (8/19) in large aneurysms. The mean VER of embolized aneurysms in each size was 30%, 22% and 17%, respectively. There was a correlation between the percentage of stable aneurysms and the mean VER. On the other hand, there seemed to be a difference of VER for the stability of embolized aneurysms between ruptured aneurysms and unruptured ones. In small aneurysms with small necks, the stability of embolized aneurysms in ruptured ones was obtained only when the VER was greater than 30%, whereas it was found in unruptured ones even though the VER was less than 20%. In conclusion, the long-term stability of embolized aneurysms was obtained in small-sized aneurysms, especially small neck aneurysms, and unruptured ones. The VER is a good, objective index to predict the long-term stability of embolized aneurysms.
Evaluation of Aneurysm Stability After Endovascular Embolization With Guglielmi Detachable Coils: Correlation Between Long-Term Stability and Volume Embolization Ratio
