Use of Personalized Printed 3-Dimensional Kidney Models for Simulation before Nephron Sparing Surgery: Methodology and Examples from a Case Series

Introduction: Nephron sparing surgery may be challenging in cases of complex or aberrant renal anatomy. 3-Dimensional printing technology has allowed the creation of 3-dimensional models that can aid in preoperative surgical planning and simulation. We describe the construction of personalized 3-dimensional kidney models, and present a series of patients with complex surgical anatomy to illustrate their use in surgical planning and performance of complex nephron sparing surgery. Methods: Three patients with complex renal masses were identified. Contrast enhanced computerized tomography studies were used to create segmentation images based on separate scan phases, which were overlaid to create virtual 3-dimensional models. High-fidelity 3-dimensional physical models were then created using 3-dimensional printing technology. The 3-dimensional models were used as an aid in the surgical planning and performance of nephron sparing surgery. Results: Three patients with complex renal anatomy presented with T1b or T2 renal masses. Two patients had absolute or relative indications for nephron sparing surgery and in 1 patient a benign mass was suspected on imaging. The 3-dimensional kidney models were constructed based on preoperative cross-sectional imaging to evaluate the feasibility of nephron sparing surgery and to simulate the surgical approach. All patients underwent successful nephron sparing surgery with negative surgical margins and preservation of renal function at followup. Conclusions: We describe the creation of personalized 3-dimensional kidney models to facilitate the visualization of the renal mass and its relationship with surrounding structures, the identification of renal and tumor vasculature, and the evaluation of aberrant anatomy. These 3-dimensional models represent a valuable tool for preoperative planning and simulation in cases with complex anatomical considerations.