3D Printing in Surgical Fields
First patented by American engineer Charles Hull in 1984, three-dimensional (3D) printing is based on an additive technology by which materials are gradually layered out to create 3D objects. Depending on the objective of the 3D print, it can be classified according to the basic material used – solid, liquid, or powder. A rapidly evolving field in the medical industry, the advent of 3D printing has revolutionized surgical fields in particular.
In their most widely used clinical application, 3D printers can generate 3D models of an individual’s body part. Producing highly accurate and customized reproductions obtained from patients’ radiological images, these models increase a surgical team’s anatomical insight. In preoperative planning in particular, they enhance the 3D perception of the planned operation, enabling a surgeon to visualize and practice the surgery, enabling the preadaptation of surgical instruments. This can shorten the duration of an operation while improving precision, which is particularly important for reconstructive surgery 1. Surgeries supported by 3D models have been shown to outperform those enhanced by conventional 2D imaging and 3D virtual models 2.
For example, facial reconstructive surgery targets an intricate anatomy – being able to print out a high-resolution 3D model of a facial injury allows for detailed, efficient and accurate preoperative planning and preparation, including as regards how best to maneuver instruments within a narrow operative field.
Beyond patient-specific anatomical models, 3D printing has also been met with an increasing number of applications across a variety of surgical disciplines – extending the range of possible uses to processes including but not limited to pre-operative planning, patient counselling, student and resident education, surgical training, and intraoperative navigation.
Patient-specific implants can also be 3D-printed – planned based on accurate 3D imaging and thus resulting in precisely fitting implants – to restore a patient’s proper anatomy and function. In cranio-maxillofacial surgery, for example, titanium implants are used for load-bearing reconstruction following mandibular resections 3; Similarly, customized patient-specific implants are integrated with dental implants for dental arch and occlusion restoration 4. Patient-specific implants are also used in orthopedics for bony reconstruction following tumor resections 5 and cervical spine reconstruction 6. In neurosurgery, patient-specific implants are used in cranioplasty for reconstructing skull defects 7.
Finally, recently, 3D printing was leveraged to create surgical tools, alongside patient-specific models or implants in the context of reconstructive procedures 8.
In the future, it will be important to reduce the manufacturing costs and time required for 3D printing in order to further increase its accessibility. Meanwhile, technological challenges to be addressed include the need for increased resolution, speed, and full compatibility with biological materials. In addition, the 3D printing of biological structures, recreating the architecture and functionality of real human organs and tissues, will also represent an area of fertile future research, including in the form of the 3D bio-printing of viable cells to build back missing bone or soft tissue. 3D printing in surgical fields will ostensibly continue to see many more innovative treatment modalities in the near future.
References
1. Shilo, D., Emodi, O., Blanc, O., Noy, D. & Rachmiel, A. Printing the Future—Updates in 3D Printing for Surgical Applications. Rambam Maimonides Med. J. (2018). doi:10.5041/rmmj.10343
2. Pugliese, L. et al. The clinical use of 3D printing in surgery. Updates in Surgery (2018). doi:10.1007/s13304-018-0586-5
3. Leiser, Y., Shilo, D., Wolff, A. & Rachmiel, A. Functional reconstruction in mandibular avulsion injuries. J. Craniofac. Surg. (2016). doi:10.1097/SCS.0000000000003104
4. Rachmiel, A., Shilo, D., Blanc, O. & Emodi, O. Reconstruction of complex mandibular defects using integrated dental custom-made titanium implants. Br. J. Oral Maxillofac. Surg. (2017). doi:10.1016/j.bjoms.2017.01.006
5. Pruksakorn, D. et al. Rapid-prototype endoprosthesis for palliative reconstruction of an upper extremity after resection of bone metastasis. Int. J. Comput. Assist. Radiol. Surg. (2015). doi:10.1007/s11548-014-1072-2
6. Xu, N. et al. Reconstruction of the upper cervical spine using a personalized 3D-printed vertebral body in an adolescent with ewing sarcoma. Spine (Phila. Pa. 1976). (2016). doi:10.1097/BRS.0000000000001179
7. Jardini, A. L. et al. Cranial reconstruction: 3D biomodel and custom-built implant created using additive manufacturing. J. Cranio-Maxillofacial Surg. (2014). doi:10.1016/j.jcms.2014.07.006
8. George, M., Aroom, K. R., Hawes, H. G., Gill, B. S. & Love, J. 3D Printed Surgical Instruments: The Design and Fabrication Process. World J. Surg. (2017). doi:10.1007/s00268-016-3814-5