Evaluation of the characteristics of various types of coils for the embolization of intracranial aneurysms with an optical pressure sensor system.
BACKGROUND
In coil embolization for an intracranial aneurysm, it is important to appropriately choose the coil most suitable for coping with various unforeseen situations. Additionally, because dense coil packing of the aneurysm sac is the most important factor to avoid a recurrence, properly selecting the coil is essential. In this article, the authors measured the coil insertion pressure of various types of coils with a newly developed sensor system, and coil characteristics were investigated.


METHODS
The sensor consists of a hemostatic valve connected to the proximal end of a microcatheter. The sensor principle is based on an optical system. Using this, an experimental silicone aneurysm embolization was performed automatically at constant speed. The pattern of the insertion pressure and the maximum insertion pressure (MIP) were analyzed for the various types of coils. The sensor continuously monitored the mechanical force during the insertions.


RESULTS
The sensor adequately recorded the coil insertion pressure during embolization in each coil. MIP was generally ranked in order of the coil type. The soft type coils required relatively less insertion pressure than standard/helical and 3D type. As for the patterns of coil insertion pressure, each coil presented a saw-like pressure pattern, though we observed some slight differences. 3D type coils showed peak pressure at the moment of "painting". Coil loop diameters barely affected MIP. However, as to the patterns of pressure, larger size coils more often presented the peak.


CONCLUSIONS
Coil characteristics were well evaluated. The results obtained here reflected some actual clinical experience. Furthermore, collecting the in vivo study is mandatory, which may provide clinically useful data.
Matsubara
Noriaki
N
Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan. mnoriaki0817@yahoo.co.jp
Miyachi
Shigeru
S
Nagano
Yoshitaka
Y
Ohshima
Tomotaka
T
Hososhima
Osamu
O
Izumi
Takashi
T
Tsurumi
Arihito
A
Wakabayashi
Toshihiko
T
Sano
Akihito
A
Fujimoto
Hideo
H
D004621:Embolization, Therapeutic / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000295:instrumentation*; D006801:Humans; D002532:Intracranial Aneurysm / Q000503:physiopathology* / Q000601:surgery*; D008365:Manometry / Q000295:instrumentation*; D055096:Optical Devices; D011312:Pressure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers