gms | German Medical Science

Objective: To assess feasibility and imaging quality of aneurysm-configuration and aneurysm-carrying blood vessels of the circle of Willis using 3D-fluoroscopy and intravenous contrast application during cerebral aneurysm surgery.

Method: 7 patients were positioned on a carbon table with their head fixed in a carbon Mayfield clamp. 60 ml of iodine contrast agent were administered by a central venous catheter. With a delay of 12 seconds, a 3-D fluoroscopy scan was performed (Medtronic O-Arm^®). The Dicom data set was transferred to an Apple PowerMac workstation and reconstructed using the OsiriX imaging software.

Results: No adverse effects were observed after the rapid intraoperative administration of the contrast agent. In images acquired before clip-placement, the configuration of the aneurysm, the aneurysm-carrying vessel and the distal vessel anatomy were well assessable. After placement of the clip, the course of blood vessels proximal and distal of the clip was clearly visible, the patency of the distal vessels was clearly visible. After clipping, however, the aneurysm itself and its close vicinity could not be assessed sufficiently due to metal clip artifacts in the imaging data, to decide whether it was completely occluded. In particular, it could not be assessed whether the aneurysm was completely occluded or not.

Conclusions: Intraoperative angiography of intracranial vessels by intravenous contrast-enhanced 3D-fluoroscopy by supplies image data, which can be quickly processed to assess the configuration of an aneurysm. After placement of a clip, the contrast filling of the vessels proximal and distal to an aneurysm can be clearly assessed. However, the current image data routines do not allow the calculation of data that can be used to reliably determine complete aneurysm occlusion. Enhanced image processing could improve this technique to become a useful intraoperative imaging tool.