title: Simulation of and training for cerebral aneurysm clipping with 3-dimensional models.
abstract: OBJECTIVE
  With improvements in endovascular techniques, fewer aneurysms are treated by surgical clipping, and those aneurysms targeted for open surgery are often complex and difficult to treat. We devised a hollow, 3-dimensional (3D) model of individual cerebral aneurysms for preoperative simulation and surgical training. The methods and initial experience with this model system are presented.
  
  
  METHODS
  The 3D hollow aneurysm models of 3 retrospective and 8 prospective cases were made with a prototyping technique according to data from 3D computed tomographic angiograms of each patient. Commercially available titanium clips used in our routine surgery were applied, and the internal lumen was observed with an endoscope to confirm the patency of parent vessels. The actual surgery was performed later.
  
  
  RESULTS
  In the 8 prospective cases, the clips were applied during surgery in the same direction and configuration as in the preoperative simulation. Fine adjustments were necessary in each case, and 2 patients needed additional clips to occlude the atherosclerotic aneurysmal wall. With these 3D models, it was easy for neurosurgical trainees to grasp the vascular configuration and the concept of neck occlusion. Practicing surgery with these models also improved their handling of the instruments used during aneurysm surgery, such as clips and appliers.
  
  
  CONCLUSIONS
  Using the hollow 3D models to simulate clipping preoperatively, we could treat the aneurysms confidently during live surgery. These models allow easy and concrete recognition of the 3D configuration of aneurysms and parent vessels.
authors.affiliation: Department of Neurosurgery, Kanto Medical Center, NTT EC, Tokyo, Japan.
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Kimura
authors.forename: Akio
authors.initials: A
authors.lastname: Morita
authors.forename: Kengo
authors.initials: K
authors.lastname: Nishimura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Aiyama
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Itoh
authors.forename: Syunsuke
authors.initials: S
authors.lastname: Fukaya
authors.forename: Shigeo
authors.initials: S
authors.lastname: Sora
authors.forename: Chikayuki
authors.initials: C
authors.lastname: Ochiai
mesh_terms: D002533:Cerebral Angiography / Q000379:methods; D002536:Cerebral Arteries / Q000473:pathology* / Q000601:surgery*; D017076:Computer-Aided Design; D004503:Education, Medical, Graduate / Q000379:methods; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D008953:Models, Anatomic; D019635:Neurosurgical Procedures / Q000193:education / Q000295:instrumentation / Q000379:methods; D011108:Polymers; D011446:Prospective Studies; D012189:Retrospective Studies; D013525:Surgical Instruments; D013663:Teaching; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000193:education* / Q000295:instrumentation / Q000379:methods
chemical_list: D011108:Polymers