Three-dimensional printing of anatomically accurate, patient specific intracranial aneurysm models

Abstract

ObjectiveTo develop and validate a method for creating realistic, patient specific replicas of cerebral aneurysms by means of fused deposition modeling.MethodsThe luminal boundaries of 10 cerebral aneurysms, together with adjacent proximal and distal sections of the parent artery, were segmented based on DSA images, and corresponding virtual three-dimensional (3D) surface reconstructions were created. From these, polylactic acid and MakerBot Flexible Filament replicas of each aneurysm were created by means of fused deposition modeling. The accuracy of the replicas was assessed by quantifying statistical significance in the variations of their inner dimensions relative to 3D DSA images. Feasibility for using these replicas as flow phantoms in combination with phase contrast MRI was demonstrated.Results3D printed aneurysm models were created for all 10 subjects. Good agreement was seen between the models and the source anatomy. Aneurysm diameter measurements of the printed models and source images correlated well (r=0.999; p<0.001), with no statistically significant group difference (p=0.4) or observed bias. The SDs of the measurements were 0.5 mm and 0.2 mm for source images and 3D models, respectively. 3D printed models could be imaged with flow via MRI.ConclusionsThe 3D printed aneurysm models presented were accurate and were able to be produced inhouse. These models can be used for previously cited applications, but their anatomical accuracy also enables their use as MRI flow phantoms for comparison with ongoing studies of computational fluid dynamics. Proof of principle imaging experiments confirm MRI flow phantom utility.

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.…”

Quantification of velocity reduction after flow diverter placement in intracranial aneurysm: An ex vivo study with 3D printed replicas

“…The fabrication of aneurysm replicas has been described elsewhere [13]. Briefly, digital surface models were created retrospectively from segmented 3D digital subtraction angiography images that were acquired during clinical diagnosis.…”

“…The method can be carried out in 2D (single slice), 3D (multiple slices), or 4D (multiple slices + time), where the fourth dimension is time and flow is visualized at different phases in the cardiac cycle. Previous work has shown that pcMRI can be carried out in anatomically accurate, 3D printed aneurysm replicas [12][13]. Herein we present comparisons between the hemodynamics before and after placement of a flow diverter in aneurysm replicas (n=3).…”

Innovations in surgery simulation: a review of past, current and future techniques

“…Some newly developed multimaterial 3D printers can produce models with multiple tissue types. As a result, some of the models produced by rapid prototyping are able to replicate actual patients' anatomical structures with remarkable realism (37,(54)(55)(56)(57).…”

“…One study found a strong correlation between 3D-printed models and the actual patients' anatomy (57). Additionally, studies have shown that surgeons using these models find them easy to use and superior to the use of traditional imaging alone (54,58).…”