Anatomical Reproducibility of a Head Model Molded by a Three-dimensional Printer

Abstract

We prepared rapid prototyping models of heads with unruptured cerebral aneurysm based on image data of computed tomography angiography (CTA) using a three-dimensional (3D) printer. The objective of this study was to evaluate the anatomical reproducibility and accuracy of these models by comparison with the CTA images on a monitor. The subjects were 22 patients with unruptured cerebral aneurysm who underwent preoperative CTA. Reproducibility of the microsurgical anatomy of skull bone and arteries, the length and thickness of the main arteries, and the size of cerebral aneurysm were compared between the CTA image and rapid prototyping model. The microsurgical anatomy and arteries were favorably reproduced, apart from a few minute regions, in the rapid prototyping models. No significant difference was noted in the measured lengths of the main arteries between the CTA image and rapid prototyping model, but errors were noted in their thickness (p < 0.001). A significant difference was also noted in the longitudinal diameter of the cerebral aneurysm (p < 0.01). Regarding the CTA image as the gold standard, reproducibility of the microsurgical anatomy of skull bone and main arteries was favorable in the rapid prototyping models prepared using a 3D printer. It was concluded that these models are useful tools for neurosurgical simulation. The thickness of the main arteries and size of cerebral aneurysm should be comprehensively judged including other neuroimaging in consideration of errors.

Measuring and Establishing the Accuracy and Reproducibility of 3D Printed Medical Models

“…Data in the same meta-analysis (12) also indicate that unsatisfactory accuracy was the most reported drawback of 3D printing technology, as stated in 34 (22%) of the 158 articles. Prominent examples include preoperative skull models that contained incorrect or entirely missing anatomy, such as occluded or altered foramina, blurred sutures, and pseudodefects not present in the skull (16) (Fig 2); vascular models that did not include arteries that were visualized on the source CT angiogram (18) or that contained artificial fenestrations, occlusions, or aneurysms that were not present on the source images (19,20); and gross deformations of dental implant guide models (21)…”

3D printing in neurosurgery: A systematic review

“…[279111419333637] One study in particular performed a more comprehensive evaluation across 22 patients with unruptured aneurysms, comparing the reproducibility of the length and thickness of the main arteries and the size of the aneurysm between a 3D-CTA and the printed model. [11] In all studies comprising both qualitative and quantitative assessments, significant differences between preoperative imaging and printed models were only observed in a few minute areas, indicating that these models accurately represent patient anatomy. Table 2 summarizes the findings from these studies.…”

Ex Vivo Aneurysm models mimicking real cases for the preoperative training of the clipping technique

“…Using cadaveric models is the most appropriate experimental model as it tests the anatomical knowledge and the arachnoid dissection technique, but it cannot mimic an in vivo environment, even if the arteries are connected to a continuous perfusion system. [3,8] The virtual reality aneurysm clipping simulation provides a realistic haptic virtual reality clipping of patient based cerebral aneurysm. The system is designed to give the user the sense of the force of the clip and the tissue deformation as the clip is positioned on the aneurysm neck.…”