The use of 3D printing as part of complex spine surgery not only helps surgeons visualize target pathology, but it can also provide valuable assistance in surgical planning and rehearsal.
With technologies becoming more affordable and accessible, advancements in 3D printing are revolutionizing clinical care. Imaging is a key factor in the development of 3D models which can help surgeons reduce time and costs and can improve outcomes for the most challenging surgeries.
"Integration of the information provided by multimodality imaging exams necessary for surgical planning can be a difficult task," said presenter Lumarie Santiago, MD, professor of radiology at the University of Texas MD Anderson Cancer Center in Houston. "This is particularly true in cases where multiple surgical specialties are working in concert.
In her case-based education exhibit, Dr. Santiago covered practical considerations for the use of 3D printing in preparation for complex spine surgeries.
Dr. Santiago described the 3D printing workflow and shared details about quality assurance as part of the planning process. She noted that the 3D printing workflow begins with determining the optimal imaging exam and sequence for performing tumor segmentation. "High-quality imaging is the basis for segmentation which includes anatomy of interest, pathology and structures that may affect the surgical approach," she said. "Imaging is our truth."
Dr. Santiago described the processes of registration and using fusion to capture the most useful information from the imaging.
When segmentation is complete, it's accuracy is verified, and the resulting 3D rendering is reviewed by the surgeon. Dr. Santiago's exhibit detailed the processes for working closely with the surgeon to prescribe surgical planes, and for integrating them into the 3D model. "After exporting the 3D model into the printer software and printing it, the accuracy of the print is verified by measuring target anatomy in three dimensions and comparing it to its imaging correlate," Dr. Santiago said.
After thorough preparation, throughout rehearsal and intraoperatively, the 3D printed model aids communication of the surgical approach to members of the multidisciplinary team.
Access and Visualization Influence Material Selection
Material selection is a critical part of the 3D printing process with material strength and flexibility and the planned surgical approach included among important factors for consideration.
"The approach for a particular case may require displacement of anatomy to allow access for surgical instruments or protect it from injury," Dr. Santiago said. "Selection of materials with similar properties to the anatomy involved in the case allows surgeons the opportunity to practice these maneuvers and test fit instruments and other devices prior to surgery."
Dr. Santiago said materials that highlight pathology and resemble tissue properties influence material selection for personalized 3D models. In addition, use of removable parts allows for visualization and manipulation of the anatomy each specialty will manage. Examples included using clear materials to allow for disease visualization in small or difficult to access areas like the epidural space.
The 3D printing team at Dr. Santiago's institution includes a biomedical engineer, radiologists and surgeons who all play important roles in the process that begins with imaging.
"Radiologists contribute their expertise in imaging protocol optimization, imaging interpretation and segmentation verification, among others," Dr. Santiago said. "3D printed models bridge the gaps in communication between multidisciplinary teams and the patients they treat."
Access the education exhibit, "3D Printing and Digital Surgical Rehearsal in Complex Spine Surgery," (INEE-8) on demand at Meeting.RSNA.org.