Background: The majority of PCNLs are performed prone, while most pre-operative CT scans are done supine. The purpose of this pilot study is to determine if there is utility of prone CT scans in pre-operative planning for prone PCNL by identifying patient populations at risk for organ injury and tract length related complications. Materials and Methods: To represent typical pre-operative planning using CT, 2D-axial-prone/supine percutaneous tract measurements were performed by minimizing the distance from the target calyx to the posterior-lateral skin in a single axial plane. The minimum distance and organ interception rates for the 2D-axial planning scans were recorded. Results: A total of 60 CT Colonography and 13 CT Urography patients were included in analysis. There were 42 females and 31 males with unspecified pathologies ranging in age from 27 to 86 years and in BMI from 17.1 to 49. Multiple logistic regression identified female gender and low BMI as predictors of organ interception on the left. On multiple linear regression comparing the difference in axial prone/supine lengths; BMI, gender, and age were not significant independent predictors of changes in tract length in any pole when prone versus supine. However, shorter supine tracts tended to lengthen when prone, and longer supine tracts tended to shorten. Conclusions: This pilot study has demonstrated that patients with very long and short estimates of tract length in the supine position may have shorter and longer tracts, respectively, with repositioning to prone. Thus, prone CT may have benefit when anticipating exceptionally long (>15cm) tract lengths. Prone scans also revealed more potential organ interceptions, particularly for low BMI and females in the left upper pole. In patients for whom prone CT demonstrates an organ interception, the urologist should consider an alternate target calyx or ultrasound guided percutaneous access to identify the most appropriate needle trajectory.

中文翻译：

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俯卧位计算机断层扫描在经皮肾镜取石术之前是否有作用？

背景：大多数 PCNL 是俯卧位进行的，而大多数术前 CT 扫描是仰卧位进行的。这项初步研究的目的是通过识别有器官损伤风险和与导管长度相关的并发症的患者人群，确定俯卧位 CT 扫描是否适用于俯卧位 PCNL 的术前计划。材料和方法：为了使用 CT 代表典型的术​​前计划，通过在单个轴向平面上最小化从目标花萼到后外侧皮肤的距离进行二维轴向俯卧/仰卧经皮道测量。记录二维轴向计划扫描的最小距离和器官截取率。结果：共有 60 例 CT 结肠造影和 13 例 CT 尿路造影患者被纳入分析。有 42 名女性和 31 名男性患有未指明的病理，年龄从 27 岁到 86 岁不等，BMI 从 17.1 到 49 岁。多元逻辑回归确定女性性别和低 BMI 是左侧器官截留的预测因素。关于比较轴向俯卧/仰卧长​​度差异的多元线性回归；当俯卧与仰卧时，BMI、性别和年龄都不是任何极杆长度变化的显着独立预测因子。然而，较短的仰卧位束在俯卧时倾向于延长，而较长的仰卧位束倾向于缩短。结论：这项初步研究表明，仰卧位束长度估计值非常长和短的患者在重新定位到俯卧位时可能分别有更短和更长的束。因此，俯卧位 CT 在预期特别长（> 15 厘米) 道长度。俯卧位扫描还揭示了更多潜在的器官拦截，特别是对于低 BMI 和左上极的女性。对于俯卧 CT 显示器官截断的患者，泌尿科医师应考虑替代目标花萼或超声引导的经皮通路，以确定最合适的进针轨迹。