In a "world first," 3D printing has been used for the creation a new sternum and part of a rib cage to replace those of a 54-year-old man with cancer.
The operation was performed at Salamanca University Hospital in Spain, and the implant was made by medical device company Anatomics, who created it using the Australian state-owned Commonwealth Scientific and Industrial Research Organization (CSIRO) 3D printing facility Lab 22 in Melbourne, Australia.The surgery was carried out by Drs. Jose Aranda, Marcelo Jimene and Gonzalo Vereda, and the procedure has been described in the European Journal of Cardio-Thoracic Surgery. The patient had suffered from a tumor in the chest wall. Surgeons knew that reconstruction would be difficult due to the complex geometry of the chest cavity and the fact that conventional titanium implants are held together by screws, which can come undone over time, causing further complications. As Dr. Aranda says:
"We thought maybe we could create a new type of implant that we could fully customize to replicate the intricate structures of the sternum and ribs [...]. We wanted to provide a safer option for our patient, and improve their recovery post-surgery."
3D technology is gaining momentum
Interest is growing in 3D technology for the medical field. According to the Cardiothoracic Surgery Network (CTSNet), the Mayo Clinic have been using 3D models made from liquid polymers since 2006.
3D models offer better opportunities for surgeons to plan procedures and to educate patients. The models have enabled surgeons to rehearse procedures, select appropriate instrumentation and divide task responsibility. They also help prepare patients in terms of what to expect and why surgery is necessary.
However, this was the first case of a sternum and rib cage being replaced using 3D technology.
3D modeling begins with 2D images such as X-ray, computed tomography (CT) or magnetic resonance imaging (MRI). A series of slices, or a "stack," of 2D images of a particular anatomical structure are used to create the model.
The Spanish team provided Anatomics with high-resolution CT data, from which they were able to create a 3D construction of the chest wall and tumor, allowing the surgeons to plan and accurately define resection margins.
From here, a rigid sternal core and semi-flexible titanium rods were created to act as prosthetic ribs attached to the sternum. The printer directed an electron beam at a bed of titanium powder in order to melt it and create each layer. The process was repeated, layer by layer, until the implant was complete.
"3D printing has significant advantages over traditional manufacturing methods, particularly for biomedical applications," says Alex Kingsbury of CSIRO. "As well as being customizable, it also allows for rapid prototyping - which can make a big difference if the patient is waiting for surgery."
Once completed, the implant was sent by courier to Spain, where it was implanted into the patient.
Dr. Aranda pronounced the operation a success, commenting that the team had been able to create a body part that was "fully customized and fitted like a glove."In May, Medical News Today reported on the use of 3D implants in three babies who suffered from life-threatening airway problems.