Ahmed Ghazi1, Patrick Saba2, Rachel Melnyk2, Jean Joseph2. 1. University of Rochester Medical Center, Division Department of Urology, 601 Elmwood Ave, Rochester, NY. Electronic address: Ahmed_Ghazi@URMC.rochester.edu. 2. University of Rochester Medical Center, Division Department of Urology, 601 Elmwood Ave, Rochester, NY.
Abstract
BACKGROUND: Three-dimensional (3D) printing technology has been utilized to create patient-specific (PS) replicas as visual aids for surgical planning.1-4 However, they cannot recreate the operative experience due to a lack of realistic tissue characteristics. OBJECTIVES: Develop anatomically accurate, realistic, PS partial nephrectomy platforms suitable for pre-operative surgical rehearsals using 3D-printing and hydrogel casting. MATERIAL: Patient CT scans were segmented into a computer-aided design (CAD) file and used to create injection casts. Kidney and tumor casts along with hollow vascular and urinary structures were 3D-printed. The hilar structures and tumor were registered into the kidney cast, injected with poly-vinyl alcohol (PVA) hydrogel, and processed to create the kidney phantom. Mechanical and functional testing protocols were completed to confirm that the properties of PVA matched the live tissue.5 Anatomical accuracy was confirmed by CT scanning the phantom and creating another CAD, which was compared to the original patient CAD. Full-procedural PS rehearsals were completed 24-48 hours prior to their respective live surgeries. Clinically relevant metrics (warm ischemia time, estimated blood loss, and positive surgical margins) from each rehearsal and live case were compared using a Wilcoxon-rank sum test. RESULTS: The 7%-3freeze/thaw PVA best recreated the mechanical and functional properties of porcine kidneys, while anatomical verification showed ≤1 mm deviation of the kidney and tumor from the patient anatomy and ≤3 mm for the hilar structures. PS rehearsal platforms were fabricated using these methods for 8 patients (average tumor size 5.92 cm and nephrometry score 9.8). A positive correlation was found for warm ischemia time and estimated blood loss between rehearsals and live surgeries. CONCLUSION: This reproducible method shows high anatomical accuracy, realistic tissue properties, and translational effects between rehearsals and live surgery. To determine the effects on patient outcomes, future studies will compare the impact of completing a pre-operative rehearsal vs standard surgical preparation.
BACKGROUND: Three-dimensional (3D) printing technology has been utilized to create patient-specific (PS) replicas as visual aids for surgical planning.1-4 However, they cannot recreate the operative experience due to a lack of realistic tissue characteristics. OBJECTIVES: Develop anatomically accurate, realistic, PS partial nephrectomy platforms suitable for pre-operative surgical rehearsals using 3D-printing and hydrogel casting. MATERIAL: Patient CT scans were segmented into a computer-aided design (CAD) file and used to create injection casts. Kidney and tumor casts along with hollow vascular and urinary structures were 3D-printed. The hilar structures and tumor were registered into the kidney cast, injected with poly-vinyl alcohol (PVA) hydrogel, and processed to create the kidney phantom. Mechanical and functional testing protocols were completed to confirm that the properties of PVA matched the live tissue.5 Anatomical accuracy was confirmed by CT scanning the phantom and creating another CAD, which was compared to the original patient CAD. Full-procedural PS rehearsals were completed 24-48 hours prior to their respective live surgeries. Clinically relevant metrics (warm ischemia time, estimated blood loss, and positive surgical margins) from each rehearsal and live case were compared using a Wilcoxon-rank sum test. RESULTS: The 7%-3freeze/thaw PVA best recreated the mechanical and functional properties of porcine kidneys, while anatomical verification showed ≤1 mm deviation of the kidney and tumor from the patient anatomy and ≤3 mm for the hilar structures. PS rehearsal platforms were fabricated using these methods for 8 patients (average tumor size 5.92 cm and nephrometry score 9.8). A positive correlation was found for warm ischemia time and estimated blood loss between rehearsals and live surgeries. CONCLUSION: This reproducible method shows high anatomical accuracy, realistic tissue properties, and translational effects between rehearsals and live surgery. To determine the effects on patient outcomes, future studies will compare the impact of completing a pre-operative rehearsal vs standard surgical preparation.
Authors: Jonathan L Silberstein; Michael M Maddox; Phillip Dorsey; Allison Feibus; Raju Thomas; Benjamin R Lee Journal: Urology Date: 2014-06-21 Impact factor: 2.649
Authors: Daniel Schmauss; Gerd Juchem; Stefan Weber; Nicolas Gerber; Christian Hagl; Ralf Sodian Journal: Ann Thorac Surg Date: 2014-06 Impact factor: 4.330
Authors: Rachel Melnyk; Bahie Ezzat; Elizabeth Belfast; Patrick Saba; Shamroz Farooq; Timothy Campbell; Stephen McAleavey; Mark Buckley; Ahmed Ghazi Journal: World J Urol Date: 2019-11-02 Impact factor: 4.226