Computer-aided design and computer-aided manufacturing (CAD/CAM) are extending their reach from industrial and engineering pursuits into the patient care arena, with the technology now being used to aid in breast reconstruction for people with cancer, as a recent project has demonstrated.
Normally employed in such undertakings as the design of buildings, bridges, and aircraft, CAD/CAM techniques allow for the fabrication of tailor-made, complex parts with high precision. As Professor Dietmar Werner Hutmacher of Georgia Institute of Technology in Atlanta and Queensland University of Technology in Kelvin Grove, Queensland, Australia, and study coauthors explain in the journal Biofabrication, the ability to build patient-specific models based on medical imaging data offers major potential. A relatively new clinical area of application for these techniques is breast reconstruction.
More than 300,000 breast reconstructions are performed annually in the United States alone, using nondegradable silicone implants or by means of transplantation of autologous tissue consisting of skin, fat, muscle, and connected vasculature. A new approach based on tissue-engineering principles is under development. Multiple studies have demonstrated the creation of vascularized adipose constructs; current efforts are directed toward making the concept clinically relevant.
Hutmacher’s group received informed consent to obtain images from a 46-year-old female patient with invasive ductal carcinoma. They performed laser scanning from three angles as the patient remained in an upright position with each arm at a 90° angle. The images were then imported into a software package that produced a single image representing the patient’s breast and surrounding thorax region. That image was then used to form a three-dimensional (3D) model that the surgical team used as an operative aid during autologous tissue reconstruction.
The result was a more perfect breast shape with a higher degree of symmetry between the breasts. However, the procedure does have drawbacks: It requires a long duration of anesthesia (5 to 10 hours), causes considerable blood loss, and raises problems at the donor site including wide and unsightly scars, abdominal weakness, abdominal bulge, and hernia.
Researchers have begun exploring ways to bypass these problems, possibly by following a tissue-engineering approach to breast reconstruction. The investigators were able to derive from the imaged data a solid breast model that they digitally processed for the fabrication of customized scaffolds for breast tissue engineering. In theory, a patient’s own cells could be harnessed and grown onto the highly specific scaffold and then transferred to the affected area, thus eliminating the need to transfer tissue from other parts of the body. This, in turn, would reduce anesthesia duration, blood loss, and scarring.
Hutmacher and team have a long-term goal of providing a CAD/CAM-based solution to the breast solution field following a tissue-engineering approach. But as they demonstrated in the current study, laser imaging and rapid prototyping can already be employed for better outcomes in surgery using the current gold standard of autologous breast reconstruction. ONA