3D printed kidney
An artificial kidney with hydrogel injected into it to give it a lifelike feel.
Physicians at the University of Rochester Medical Centre (URMC) have used 3D printers to develop fabricated artificial organs that can even physically bleed when cut.
These 3D models are said to be incredibly realistic and mimic the real thing. Initially the replicas are to be used to create simulations for training and could soon be widely used to rehearse complex operations.
The artificial human anatomy parts were made as part of a programme which has been named the Simulated Inanimate Model for a Physical Learning Experience, or SIMPLE. It is the brainchild of Ahmed Ghazi, M.D., M.SC., an assistant professor in the Department of Urology and Jonathan Stone, M.D., a Neurosurgery resident who also holds a degree in biomedical engineering.
During the process, images are converted from medical scans into computer generated designs and, through the assistance of 3D printing, fabricating lifelike organs that can be poked, prodded and dissected.
“Very few surgical simulations are successful at recreating the live event from the beginning to the end,” said Ghazi. “What we have created is a model that looks, feels, and reacts like a live organ and allows trainees and surgeons to replicate the same experience they would face in the operating room with a real patient.”
The development of the method begun two years ago when Ghazi and Stone first met. It begins with images obtained from MRI, CT or ultrasound scans into computer-assisted designs (CAD). Instead of using these designs to create rigid plastic replicas of human anatomy, like has been done previously, Ghazi and Stone converted the CADs into moulds which were built using a 3D printer. Then, the moulds are injected with a hydrogel which solidifies the model after freezing. Since the water consistency of the hydrogel is identical to that found in our bodies, the artificial organs have the same feel as the real thing.
Working with the University of Rochester Department of Biomedical Engineering, the team also ensured the models had the same mechanical properties as real tissue, conducting a number of scientific tests.
Once the basic models had been created, the pair began to tweak the designs in order to change the pathology. Using the 3D printer to create more rigid structures, the team are also able to create bone to simulate procedures involving the spine and skull.
While just being able to handle and examine a replica organ can provide surgeons with a great deal of insight, Ghazi and Stone wanted to further enhance the model. Already able to observe where blood vessels enter and exit the organ, and locate a tumour if there is one, they wanted the students to be able to replicate the complete surgical experience. This required building the rest of the human anatomy so the entire process of guiding instruments to the right location, moving other organs out the way, clamping blood vessels, and resecting and removing tumours could be practiced.
As well as the whole human anatomy being produced, artificial blood vessels were implemented, and connected to bags of red dye that will ‘bleed’ if cut. This was also done with other bodily fluids, such as urine or bile, to show students how sensitive or tough certain interior parts of the body are.
The assembled unit could then be brought into the operating room, hooked up to a robotic surgical system, and then the entire procedure could be simulated.
“The fact that we could someday have surgeons practice procedures on these models before going to the operating room helps eliminate the unknown, increases safety, and improves the quality of care,” said Ghazi. “Patients can, in turn, reassure themselves by asking their surgeons ‘how did the rehearsal go yesterday?’ That is going to be the future of surgery.”