Application of virtual reality techniques in preoperative surgical planning for intracranial anterior circulation aneurysms

Objective 　To investigate the value of virtual reality (VR) technique in the surgical planning for anterior circulation aneurysms of Willis circle. Methods 　A total of 50 patients with 57 aneurysms confirmed by CT angiography in the anterior circle of Willis were enrolled in this study. In preoperative Hunt-Hess scale, grade Ⅰ was designated in 7 patients, grade Ⅱ in 22, grade Ⅲ in 17, grade Ⅳ in 3, grade Ⅴ in 1 patient. Among the aneurysms, 16 were small (≤5mm in diameter), 28 medium (5-15mm), 10 large (15-25mm) and 3 giant (≥25mm) in size. The thin-slice head scanning data were achieved by 64-slice spiral CT machine. These data was then transferred into Dextroscope image workstation. The virtual imaging system generated clear and vivid virtual images. We compared the findings between simulation surgical operation and actual operation. Results 　VR system make the operator felt "personally on the scene" and was able to communicate with the imaging. It could not only visually display the anatomical structures in three dimensions, but also could simulate some surgical procedures, which basically simulated the same outcome of actual operation. All the 50 patients were successfully treated by microsurgical clipping of main aneurysmal or contributory aneurysmal necks. Conclusions 　The surgeons is able to be more confident, and the identification for the complex vascular abnormality is improved by planning operative procedure in virtual-reality environment. The virtual-reality system makes the actual operative procedure more concise, thus it is of positive value in surgery for intracranial aneurysm.