The ability to produce highly detailed three-dimensional models from radiological scans is a huge advance, not only in prosthetics and implants but also in surgical preparation.
Hospitals generally use 3D printing to produce highly detailed models of patient-specific structures from CT and MRI scans. Images from scans are converted into Computer-Aided Design (CAD) files and printed out in a layer-by-layer fashion with polymer resins.
These 3D models help surgeons to plan and optimize surgery, which improves operating and recovery times, thus improving outcomes. The models are also useful as teaching tools.
For example, in cancer of the jaw, where a section of the mandible has been removed, a scan of the jaw can be printed. This enables surgeons to optimize the design and practice fitting the prosthesis for individual cases.
Our biggest customers are maxillofacial labs, where titanium plates are required and a high degree of surgical planning is paramount.
The advantages of this individualized surgery planning appear to be considerable.
Surgeons are seeing huge benefits in surgical planning, improved patient treatment, shorter theatre times and hospital stays where incisions are more accurate.
An Improved Understanding of the Anatomy
For pediatric cardiologist Dr. Matthew Bramlet from the Children’s Hospital of Illinois, teamed up with the Jump Trading Simulation and Education Center, the ability to model a structure in 3D, as opposed to seeing it in 2D on a screen, is vital for an “improved understanding” of the anatomy.
“Imagine trying to manipulate through a 3D maze with only 2D images of the maze. Congenital heart disease, which consists of complex 3D structures in unusual orientations is the perfect substrate for demonstrating the benefit of going from 2D to 3D. When one encounters a confusing 3D spatial orientation issue, why should we settle for anything other than an exact replica of the complex 3D structure?”
In his experience, just replicating the heart in 3D improves understanding significantly:
I would encourage children’s hospitals to dedicate resources to this innovation as it can have direct patient impact in dramatic ways.
Cost of a 3D Printing Service Still Very Expensive
The setting up and running costs of a 3D printing service for a single department or hospital can make it prohibitive though. Mr. Sherry explained:
An average hospital in the U.K. orders around €11,000 – €16,000 worth of models per annum, which is far below the running costs of a printer, software and operating costs.
Part owned by the National Health Service, Replica 3dm is a printing service hub of the NHS, and is connected to the NHS Picture Archiving and Communications System for easy transfer of scans.
Depending upon the size of the model, the turnaround time is around 3 days. A mandible for instance takes 12 to 16 hours to print. But Mr. Sherry is convinced printing times will plummet.
We haven’t quite reached the Star Trek replicator but we’re not far away. New printers entering the market have reduced this to around 1 hour with the same accuracy. It won’t be long before this is minutes and it happens in the operating theatre.
Replica 3dm uses a Stratasys printer with a photopolymer acrylic, printing in 28 micron layers, enabling very accurate modeling and a high-quality finish. The resin is flexible enough to allow surgeons to drill it and strong enough to support titanium plates.
Models are printed with a combination of build and support material, with the build material costing 25 cents per gram of build and 11 cents per gram of support.
The Jump Trading Simulation and Education Center uses a plaster composite ink-jet binder printer by Z-Corp (now 3D Systems). The cost of materials per printed heart model ranges from between €13 to €52.
Replicating Texture Is Still a Long Way Off
For all of their tangible benefits, the models don’t have the same texture or consistency as the organs they are modeling. For Dr. Bramlet that’s a secondary concern.
“I have yet to meet a surgeon who doesn’t want some pliable form such as latex or silicone, and silicone printers are on the horizon, but I believe the first goal of improved understanding of the actual anatomy surpasses the ability to surgically manipulate a model.”
So replicating texture is still a way off, but for the time being, 3D printing can reproduce the size and shape of an organ with astounding precision, the benefits of that are tangible.