Hespel AM, Hudson J, Wilhite R.
Introduction/Purpose: Cross-sectional imaging modalities such as multislice computed tomography (CT), magnetic resonance imaging (MRI) or 40 ultrasound, allow creation of a high resolution 3D image within minutes using acquired data. In human medicine, 3D virtual representations of volumetric data aid in surgical planning and provide a better learning experience for the surgeons and trainees involved. With 3D printing, it is poss ible to prototype these 3D models , creating an accurate and palpable representation of the anatomy within hours.
Methods: Patients requiring advanced spinal , facia l or laryngeal surgery were prospectively recruited upon surgeons’ request. Images were acquired using a single slice CT, exported into a rapid prototyping software, Mimics Innovation Suite®. This software allows creation of accurate 3D models. Using thresholding and segmentation processes, the non-anatomical parts and non-clinically useful parts of the models were removed. Once the model rendered, they were corrected and printed using a Replicator2® 3D printer. The models were all printed using polylactic-acid-polymer, a corn based plastic at a temperature of 230 degrees celsius .
Results: Two dogs with atlanto-axial sublu xation , one dog with thoracic spinal malformation, one dog with a C2 fracture, one dog with a laryngeal mass and one horse with multiple comminuted facial fractures were included. The use of 3D models allowed the surgeons to choose preoperatively the ideal surgical approach as well as the type and size of implants needed in all but one of the surgeries. In this last case , the fractu re of the axis was considered stable based on the model and surgery was not performed. Teaching models of the canine and feline bronchial tree were printed for use in the endoscopy room. Furthermore, models for research projects including one involving gangliosidosis type 2 and another involving the podotrochlear apparatus of the laminitic horse were also created.
Discussion/Conclusion: Rapid prototyping is used commonly in human medicine for preoperative planning, and creation of custom made prostheses. The use of rapid prototyping is less commonly reported in the veterinary literature. 3D models are now commonly used in our institution to help the planning of complicated surgeries, subjectively reducing the surgery time and the complications associated with longer surgery. In both veterinary and human medicine the models have proven to enhance communication across clinicians, students and clients. Models have also been proven useful as a teaching tool for both undergraduate and trainees. Desktop 3D printers, which are inexpensive and user friendly, could popularize rapid prototyping in the future.
NB: 3D models will be provided to allow a hands-on approach for the audience.