Advanced Manufacturing in the Fabrication of a Lifelike Brain Glioblastoma Simulator for the Training of Neurosurgeons

Abstract

Neurosurgeons require considerable expertise and practical experience to deal with the critical situations commonly encountered in complex surgical operations such as cerebral cancer; however, trainees in neurosurgery seldom have the opportunity to develop these skills in the operating room. Physical simulators can give trainees the experience they require. In this study, we adopted advanced molding and replication techniques in the fabrication of a physical simulator for use in practicing the removal of cerebral tumors. Our combination of additive manufacturing and molding technology with elastic material casting made it possible to create a simulator that realistically mimics the skull, brain stem, soft brain lobes, and cerebral cancer with cerebral tumors located precisely where they are likely to appear. Multiple and systematic experiments were conducted to prove that the elastic material used herein was appropriated for building professional medical physical simulator. One neurosurgical trainee reported that under the guidance of a senior neurosurgeon, the physical simulator helped to elucidate the overall process of cerebral cancer removal and provided a realistic impression of the tactile feelings involved in craniotomy. The trainee also learned how to make decisions when facing the infiltration of a cerebral tumor into normal brain lobes. Our results demonstrate the efficacy of the proposed physical simulator in preparing trainees for the rigors involved in performing highly delicate surgical operations.

Keywords: brain simulator; cerebral cancer surgery practice; neurosurgeon surgical simulator.

Figure 1

3D-printed parts of medical simulator: (a) top and bottom of skull with position pins; (b) brain stem with position hooks; (c) assembled skull and brain stem.

Figure 2

(a) Mold of brain lobe printed using a 3D printer (Fortus 360mc, Stratasys) with acrylonitrile butadiene styrene (ABS); (b,c) the mold was fixed within a transparent box into which white silicon was poured to create a cast; (d) the silicon mold was sliced open using a knife and then peeled back to remove the ABS mold from within; (e) beige-colored jelly mixture was poured into the cavity; (f) to create a realistic model of the brain lobe.

Figure 3

(a) A small quantity of jelly was poured into the silicon mold; (b) placement of preformed cerebral tumor within the jelly; (c) the cast was then closed, into which the remaining jelly mixture was poured; (d) finished right parietal lobe with embedded cerebral tumor.

Figure 4

(a) Top-view image of simulator prior to assembly of the top skull, frontal lobe, and parietal lobe; (b) side-view image of simulator prior to placement of the top skull; (c) entire simulator ready for practicing surgical techniques.

Figure 5

(a) Measured height of brain lobe made of jelly wax only after 14 days; (b) measured height of brain lobe made of jelly wax and thermoplastic rubber after 14 days; (c) comparison chart showing the measured height in terms of days for both cases.

Figure 6

(a) A V-clamp was inserted into the cut for either 4 h or 8 h, representing that surgical forceps were used to make space between brain lobes during the surgery for either 4 h or 8 h; (b) a crack was observed on the hemispheric object made of jelly wax only; (c) no crack was observed on the hemispheric object made of jelly wax and thermoplastic rubber; (d) recovery ratio after 4 h for both cases, 100% recovery ratio means no crack was observed and lower recovery ratio means wider crack was found; (e) recovery ratio after 8 h for both cases.

Figure 7

The experimental results of the tensile tests for both materials.

Figure 8

(a) Dr. Liu giving a neurosurgery trainee instructions on the use of the proposed simulator; (b) adjusting the angle and orientation of the head prior to commencing surgery; (c) marking the skull with three points to guide the trainee in sawing the top skull prior to craniotomy; (d,e) cutting off the top skull to expose the brain lobes; (f) making space between the brain lobes to locate the tumor; (g) using surgical forceps to remove the tumor; (h) removal of grey tumor tissue left a cavity within the lobe (infiltration scenario); (i) withdrawal of forceps and covering of skull to complete the operation.