Mechanical and functional validation of a perfused, robot-assisted partial nephrectomy simulation platform using a combination of 3D printing and hydrogel casting
Introduction and objectives
There is a scarcity of high-fidelity, life-like, standardized and anatomically correct polymer-based kidney models for robot-assisted partial nephrectomy (RAPN) simulation training. The purpose of this technical report is to present mechanical and functional testing data as evidence for utilizing a perfused hydrogel kidney model created utilizing 3D printed injection casts for RAPN simulation and training.
Anatomically correct, tumor-laden kidney models were created from 3D-printed casts designed from a patient's CT scan and injected with poly-vinyl alcohol (PVA). A variety of testing methods quantified Young’s modulus in addition to comparing the functional effects of bleeding and suturing among fresh porcine kidneys and various formulations of PVA kidneys.
7% PVA at three freeze–thaw cycles (7%-3FT) was found to be the formula that best replicates the mechanical properties of fresh porcine kidney tissue, where mean(± SD) values of Young’s modulus of porcine tissue vs 7%-3FT samples were calculated to be 85.97(± 35) kPa vs 80.97(± 9.05) kPa, 15.7(± 1.6) kPa vs 74.56(± 10) kPa and 87.46(± 2.97) kPa vs 83.4(± 0.7) kPa for unconfined compression, indentation and elastography testing, respectively. No significant difference was seen in mean suture tension during renorrhaphy necessary to achieve observable hemostasis and capsular violation during a simulated perfusion at 120 mmHg.
This is the first study to utilize extensive material testing analyses to determine the mechanical and functional properties of a perfused, inanimate simulation platform for RAPN, fabricated using a combination of image segmentation, 3D printing and PVA casting.
Keywords3D printing High fidelity Partial nephrectomy Mechanical testing Simulation Inanimate model Perfused kidney model
Protocol/project development: RM, SM, MB, AG. Data collection or management: BE, EB, PS, SF, RM, AG. Data analysis: BE, EB, PS, SF, RM, AG. Manuscript writing/editing: RM, AG, TC.
Compliance with ethical standards
Conflict of interest
RMelnyk: none. B Ezzat: none. E Belfast: none. P Saba: none. S Farooq: none. S McAleavey: none. M Buckley: none. A Ghazi: Intuitive Surgical: Research grant, Olympus America: Consultant.
Research involving human participants and/or animals
This research was conducted utilizing porcine kidneys. Fresh porcine kidneys were acquired through the University of Rochester veterinary research facilities.
No informed consent was required for this study.
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