University of Rochester Medical Center, Division Department of Urology, 601 Elmwood Ave, Rochester, NY.
University of Rochester Medical Center, Division Department of Urology, 601 Elmwood Ave, Rochester, NY.
Urology. 2021 Jan;147:317. doi: 10.1016/j.urology.2020.10.023. Epub 2020 Oct 28.
Three-dimensional (3D) printing technology has been utilized to create patient-specific (PS) replicas as visual aids for surgical planning. However, they cannot recreate the operative experience due to a lack of realistic tissue characteristics.
Develop anatomically accurate, realistic, PS partial nephrectomy platforms suitable for pre-operative surgical rehearsals using 3D-printing and hydrogel casting.
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. 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.
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.
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.
三维（3D）打印技术已被用于创建患者特异性（PS）复制品，作为手术规划的视觉辅助工具。然而，由于缺乏真实的组织特性，它们无法重现手术过程。
使用 3D 打印和水凝胶铸造技术开发适合术前手术排练的解剖学准确、真实、PS 部分肾切除术平台。
对患者的 CT 扫描进行分割，形成计算机辅助设计（CAD）文件，并用于创建注射铸模。肾脏和肿瘤铸模以及空心血管和泌尿结构进行 3D 打印。将肾门结构和肿瘤注册到肾脏铸模中，注入聚乙烯醇（PVA）水凝胶，并进行处理以创建肾脏模型。完成机械和功能测试协议，以确认 PVA 的特性与活体组织匹配。通过对模型进行 CT 扫描并创建另一个 CAD 来确认解剖学准确性，然后将其与原始患者 CAD 进行比较。在各自的活体手术前 24-48 小时完成全程序 PS 排练。使用 Wilcoxon 秩和检验比较每次排练和活体手术的临床相关指标（热缺血时间、估计失血量和阳性手术切缘）。
7%-3 次冻融 PVA 最能再现猪肾的机械和功能特性，而解剖验证显示肾脏和肿瘤与患者解剖结构的偏差≤1mm，肾门结构的偏差≤3mm。使用这些方法为 8 名患者（平均肿瘤大小为 5.92cm，肾肿瘤评分 9.8）制造了 PS 排练平台。排练和活体手术之间的热缺血时间和估计失血量呈正相关。
这种可重复的方法具有较高的解剖学准确性、真实的组织特性，以及排练和活体手术之间的转化效果。为了确定对患者结局的影响，未来的研究将比较完成术前排练与标准手术准备的影响。
