Background: In coil embolization of neurovascular aneurysms, we have noted that few wide-necked unruptured aneurysms are successfully embolized. This prompted us to search for useful factors to assist the choice of methods of coil embolization.
Method: We first measured aneurysm size and volume using auto measurement (NVvol) and VER (NVver). Second, we calculated the volume (NVapp) and VER (NVapp) using approximation expressions. Third, we measured the end-on view neck angle using a 3 dimensional digital subtraction angiography (3D-DSA) image.
Results: NVvol and NVapp were correlated (y=0.87x). NVvol VER and NVapp VER approached 24% in 41 clinical cases. The dome/neck ratio averaged 1.15. Length of neck and the end-on view neck angle were significantly different between the stent-assisted group and the balloon-assisted group. NVvol and NVapp showed a good correlation with basic examination results in 41 clinical cases.
Conclusion: The end-on view neck angle is significantly different. This boundary neck angle was 100° for the two groups. The end on-view neck angle is thus a useful factor for deciding medical treatment strategy.