METHODS

Pre-operative computerized tomographies were used along with proprietary software to import images into the 3-D printer. Sterolithography additive manufacturing, a technique in which an ultraviolet laser is used to cure a photosensitive resin in sequential, horizontally oriented layers was employed to build the models (Medical Modeling Inc., Golden, CO). We printed 20 models with four different variations on materials and properties for 12 patients with renal masses. Subsequently the patients underwent surgical extirpation of their renal masses.

RESULTS

The four model types are demonstrated in figure 1. Initially, the models were made a firm plastic with only renal parenchyma and the mass being contrasted by a clear and pink resin. Subsequently, the collecting system and vasculature were added to the models. A second type of firm model allowed for multiple different colors to represent independently normal parenchyma, renal mass, vasculature, and collecting system. More recently, we have developed two malleable type models that enable the pre-operative simulation of tumor resection and renorrhaphy. Patients, their families and trainees consistently stated that the models enhanced their understanding of the renal tumor in relation to surrounding normal renal parenchyma and hilar structures.

CONCLUSIONS

Pre-operative physical 3-D models using readily available printing techniques can be constructed and may potentially influence both patients' and trainees' understanding of renal malignancies. With experience, 3-D printing has evolved such that models more closely approximate actual renal units. Download PPT