Rachel Melnyk1, Bahie Ezzat2, Elizabeth Belfast1, Patrick Saba1, Shamroz Farooq3, Timothy Campbell3, Stephen McAleavey2, Mark Buckley2, Ahmed Ghazi4. 1. Department of Urology, Simulation Innovation Laboratory, Univeristy of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, 14642, USA. 2. Department of Biomedical Engineering, Hajim School of Engineering, University of Rochester, 500 Joseph C. Wilson Blvd, Rochester, NY, 14611, USA. 3. School of Medicine and Dentistry, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, 14642, USA. 4. Department of Urology, Simulation Innovation Laboratory, Univeristy of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, 14642, USA. ahmed_ghazi@URMC.rochester.edu.
Abstract
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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Entities:
Keywords:
3D printing; High fidelity; Inanimate model; Mechanical testing; Partial nephrectomy; Perfused kidney model; Simulation
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