Model analysis of coil embolization of cerebral aneurysms: prediction of thrombus formation in aneurysms based on the coil embolization rate.
OBJECTIVE
Intra-aneurysmal coil embolization has been established as a common method for the intravascular treatment of cerebral aneurysms, but few studies have evaluated its long-term results. Because there is no sufficient objective landmark of complete embolization, determination of its application depends on a surgeon's experience.


METHODS
A glass cerebral aneurysm model was produced, and the changes in intra-aneurysmal hemodynamics were examined. Nylon thread with a diameter of 0.33 mm, resembling the coils clinically used for embolization, was used to fill in the model. After perfusion of glycerin solution to represent human blood, the half life of a dye injected into the aneurysm was optically measured, and the relationship between the half life and the volume embolization rate (VER) of nylon thread in the aneurysm was examined.


RESULTS
The maximal VER obtained by filling nylon thread in the aneurysm was 41.7+/- 2.9%. The half life of the dye increased with the VER and was significantly increased at VER>30%.


CONCLUSIONS
The half life of the dye in the aneurysm reflected stagnation of intra-aneurysmal hemodynamics, suggesting that the prolongation of the half life enhances thrombus formation. The results of this study suggested that VER>30% is sufficient for effective coil embolization.
Shimano
Hiroshi
H
Department of Neurosurgery, Osaka Medical College, Takatsuki, Japan. shimaan@m4.dion.ne.jp
Nagasawa
Shiro
S
Miyatake
Shin-Ichi
S
Kawanishi
Masahiro
M
Yamaguchi
Kazunobu
K
Kawabata
Shinji
S
Kuroiwa
Toshihiko
T
D002341:Carotid Artery Thrombosis / Q000503:physiopathology / Q000601:surgery*; D002343:Carotid Artery, Internal / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D004396:Coloring Agents; D004621:Embolization, Therapeutic / Q000295:instrumentation* / Q000379:methods*; D005990:Glycerol; D006801:Humans; D020766:Intracranial Embolism / Q000503:physiopathology / Q000601:surgery*; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods*; D011237:Predictive Value of Tests; D019736:Prostheses and Implants / Q000592:standards*; D014656:Vascular Surgical Procedures / Q000295:instrumentation / Q000379:methods*
D004396:Coloring Agents; D005990:Glycerol