Stability of microcatheter for cerebral aneurysm embolization after steam shaping

To compare the performance of stability after steam shaping on 4 types of microcatheters, which are commonly used for cerebral aneurysm embolization, an experimental simulation was performed. Distal portion of the microcatheters were shaped into the 90 degree with length of 5 mm with the steam under the instruction of each catheter. In the temperature kept water bath, the change of the angle of the catheter tips were recorded and measured. Several stresses were added to the tips with coaxially passing through the guiding catheter, using guidewire and Guglielmi detachable coil (GDC). The degree of straightening was prominent on braided microcatheters and on the short length of shaping. The degree of recover of the primary shaping was prominent on non-braided catheter. The most influence factor of straightening of shaped catheter tip was the stress from the manipulation of guidewire. The influence from the inserting GDC was less than the guidewire manipulation. It was shown that the decreased angle after large stress was recovered under the situation of without or with small stress. Our study shows that the nonbraided microcatheter was suitable when stability of microcatheter tip after steam shaping was requested for aneurysm coiling.