"Virtual stent" - clinical evaluation and user experience of on-the-fly stent simulation in treatment of cerebral aneurysms.

BACKGROUND Predicting final position can be challenging when treating cerebral aneurysms. Third-Party software proved helpful in selecting proper stents in treatment planning. Recent angiographic systems provide basic simulation capabilities integrated in the post-processing software to simulate position. Goal of this analysis was to evaluate the simulation process and correlation with definite position. MATERIALS AND METHODS Thirty-three datasets with fusiform (n = 10) and saccular (n = 23) aneurysms, treated with or flow-diverter, were processed. A virtual stent of the same (nominal) size was simulated and its position was compared to the treatment result. Simulated length was rated in five grades (too short, shorter, equal, longer, too long), with regard to side-branches, anchoring zone etc. Simulation quality (centerline recognition/adherence to vessel margins) was rated in three grades (no, minor or major corrections required). RESULTS Simulation was successful in 32/33 cases (97%), with one abortive attempt (3%). In 27/33 simulations (82%), there was no need for centerline refinement. Minor corrections were necessary in four and major corrections in two cases. Simulated nominal length was rated equal in 14/33 (42%) cases and shorter or longer - but within acceptable range - in each 9/33 (27%) cases. CONCLUSION Basic simulation tools available with genuine angiographic workplace software can provide good simulation capabilities without need for third-party equipment. They can facilitate treatment planning and help to avoid shortage of devices. Yet, lack of calculation of foreshortening in large vessel diameters leaves the user to rely on their experience to account for device-specific properties.