Treatment planning for image-guided neuro-vascular interventions using patient-specific 3D printed phantoms

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.

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Integrated multi-modality image-guided navigation for neurosurgery: open-source software platform using state-of-the-art clinical hardware

International Journal of Computer Assisted Radiology and Surgery ◽

10.1007/s11548-021-02374-5 ◽

2021 ◽

Author(s):

Jonathan Shapey ◽

Thomas Dowrick ◽

Rémi Delaunay ◽

Eleanor C. Mackle ◽

Stephen Thompson ◽

...

Keyword(s):

Skull Base ◽

Open Source ◽

Open Source Software ◽

Skull Base Surgery ◽

Patient Specific ◽

Software Platform ◽

Image Guided ◽

Phantom Model ◽

Technical Requirements ◽

Navigated Ultrasound

Abstract Purpose Image-guided surgery (IGS) is an integral part of modern neuro-oncology surgery. Navigated ultrasound provides the surgeon with reconstructed views of ultrasound data, but no commercial system presently permits its integration with other essential non-imaging-based intraoperative monitoring modalities such as intraoperative neuromonitoring. Such a system would be particularly useful in skull base neurosurgery. Methods We established functional and technical requirements of an integrated multi-modality IGS system tailored for skull base surgery with the ability to incorporate: (1) preoperative MRI data and associated 3D volume reconstructions, (2) real-time intraoperative neurophysiological data and (3) live reconstructed 3D ultrasound. We created an open-source software platform to integrate with readily available commercial hardware. We tested the accuracy of the system’s ultrasound navigation and reconstruction using a polyvinyl alcohol phantom model and simulated the use of the complete navigation system in a clinical operating room using a patient-specific phantom model. Results Experimental validation of the system’s navigated ultrasound component demonstrated accuracy of $$<4.5\,\hbox {mm}$$ < 4.5 mm and a frame rate of 25 frames per second. Clinical simulation confirmed that system assembly was straightforward, could be achieved in a clinically acceptable time of $$<15\,\hbox {min}$$ < 15 min and performed with a clinically acceptable level of accuracy. Conclusion We present an integrated open-source research platform for multi-modality IGS. The present prototype system was tailored for neurosurgery and met all minimum design requirements focused on skull base surgery. Future work aims to optimise the system further by addressing the remaining target requirements.

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Total Meniscus Reconstruction Using a Polymeric Hybrid-Scaffold: Combined with 3D-Printed Biomimetic Framework and Micro-Particle

Polymers ◽

10.3390/polym13121910 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1910

Author(s):

Hun-Jin Jeong ◽

Se-Won Lee ◽

Myoung Wha Hong ◽

Young Yul Kim ◽

Kyoung Duck Seo ◽

...

Keyword(s):

Shape Matching ◽

Femoral Condyle ◽

Immunohistochemical Analysis ◽

Cartilage Degeneration ◽

Patient Specific ◽

Hybrid Scaffold ◽

Meniscus Tissue ◽

Cell Source ◽

3D Printed ◽

Meniscus Regeneration

The meniscus has poor intrinsic regenerative capability, and its injury inevitably leads to articular cartilage degeneration. Although there are commercialized off-the-shelf alternatives to achieve total meniscus regeneration, each has its own shortcomings such as individualized size matching issues and inappropriate mechanical properties. We manufactured a polycaprolactone-based patient-specific designed framework via a Computed Tomography scan images and 3D-printing technique. Then, we completed the hybrid-scaffold by combining the 3D-printed framework and mixture micro-size composite which consists of polycaprolactone and sodium chloride to create a cell-friendly microenvironment. Based on this hybrid-scaffold with an autograft cell source (fibrochondrocyte), we assessed mechanical and histological results using the rabbit total meniscectomy model. At postoperative 12-week, hybrid-scaffold achieved neo-meniscus tissue formation, and its shape was maintained without rupture or break away from the knee joint. Histological and immunohistochemical analysis results showed obvious ingrowth of the fibroblast-like cells and chondrocyte cells as well as mature lacunae that were embedded in the extracellular matrix. Hybrid-scaffolding resulted in superior shape matching as compared to original meniscus tissue. Histological analysis showed evidence of extensive neo-meniscus cell ingrowth. Additionally, the hybrid-scaffold did not induce osteoarthritis on the femoral condyle surface. The 3D-printed hybrid-scaffold may provide a promising approach that can be applied to those who received total meniscal resection, using patient-specific design and autogenous cell source.

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Design, Fabrication, and Accuracy of a Novel Noncovering Lock-Mechanism Bilateral Patient-Specific Drill Guide Template for Nondeformed and Deformed Thoracic Spines

HSS Journal ® ◽

10.1177/1556331621996331 ◽

2021 ◽

pp. 155633162199633

Author(s):

Mehran Ashouri-Sanjani ◽

Shima Mohammadi-Moghadam ◽

Parisa Azimi ◽

Navid Arjmand

Keyword(s):

Thoracic Spine ◽

Sagittal Plane ◽

Ct Scanning ◽

Entry Point ◽

In Vivo Studies ◽

Patient Specific ◽

Plane Angle ◽

Severe Scoliosis ◽

3D Printed

Background: Pedicle screw (PS) placement has been widely used in fusion surgeries on the thoracic spine. Achieving cost-effective yet accurate placements through nonradiation techniques remains challenging. Questions/Purposes: Novel noncovering lock-mechanism bilateral vertebra-specific drill guides for PS placement were designed/fabricated, and their accuracy for both nondeformed and deformed thoracic spines was tested. Methods: One nondeformed and 1 severe scoliosis human thoracic spine underwent computed tomographic (CT) scanning, and 2 identical proportions of each were 3-dimensional (3D) printed. Pedicle-specific optimal (no perforation) drilling trajectories were determined on the CT images based on the entry point/orientation/diameter/length of each PS. Vertebra-specific templates were designed and 3D printed, assuring minimal yet firm contacts with the vertebrae through a noncovering lock mechanism. One model of each patient was drilled using the freehand and one using the template guides (96 pedicle drillings). Postoperative CT scans from the models with the inserted PSs were obtained and superimposed on the preoperative planned models to evaluate deviations of the PSs. Results: All templates fitted their corresponding vertebra during the simulated operations. As compared with the freehand approach, PS placement deviations from their preplanned positions were significantly reduced: for the nonscoliosis model, from 2.4 to 0.9 mm for the entry point, 5.0° to 3.3° for the transverse plane angle, 7.1° to 2.2° for the sagittal plane angle, and 8.5° to 4.1° for the 3D angle, improving the success rate from 71.7% to 93.5%. Conclusions: These guides are valuable, as the accurate PS trajectory could be customized preoperatively to match the patients’ unique anatomy. In vivo studies will be required to validate this approach.

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