Abstract: Application of mixed reality technology in surgery of primary retroperitoneal tumor        SHI Xiao-qiang*，QIU Guang-lin，LIANG Ting，et al. *Department of General Surgery，the First Affiliated Hospital of Xi'an Jiaotong University，Xi’an 710061，China
Corresponding authors：WANG Shu-feng，E-mail: dawn@mail.xjtu.edu.cn；LI Xu-qi，E-mail: lixuqi@163.com
Abstract    Objective    To explore the application value of mixed reality technique in primary retroperitoneal tumor surgery. Methods    The clinical data of 21 patients with primary retroperitoneal tumor treated in the First Affiliated Hospital of Xi'an Jiaotong University from March 2017 to April 2019 were analyzed retrospectively. The CTA image data of all patients were reconstructed into three-dimensional visualization images, and then holographic projection in the surgeon's field of vision or superimposed on the patient's real body by mixed reality technology to assist in preoperative evaluation and intraoperative navigation. Results    All the 21 patients successfully applied mixed reality technique during the operation，including 18 cases of radical tumor resection，3 cases of abdominal exploration and tumor biopsy；the median operation time was 210(40-580) minutes；the median blood loss was 300(20-1700) mL，and the median tumor diameter was 13.2(5.9-40.0) cm. There were no serious complications such as massive bleeding，intestinal anastomotic fistula and death after operation. The virtual three-dimensional model image of Hololens holographic projection clearly，stably and intuitively shows the size and location of the tumor and its anatomical relationship with adjacent organs and blood vessels. The sensitivity and specificity of evaluating tumor invasion of adjacent organs were 63.6% and 70.0% respectively，and the sensitivity and specificity of evaluating tumor invasion of adjacent important vessels were 87.5% and 84.6%，respectively. Conclusion    The mixed reality technique can project the anatomical images of primary retroperitoneal tumor and adjacent blood vessels and organs clearly and accurately，which provides a new auxiliary method for the accurate implementation of surgery.

Key words: mixed reality, preoperative evaluation, intraoperative navigation, primary retroperitoneal tumor

摘要： 目的    探讨混合现实技术在原发性腹膜后肿瘤手术中的应用价值。方法    回顾性分析2017年3月至2019年4月西安交通大学第一附属医院收治的21例原发性腹膜后肿瘤病人的临床资料。所有病人的计算机断层扫描血管造影（CTA）图像数据先进行三维可视化重建，再通过混合现实技术全息投影于外科医生视野或叠加于病人现实身体，辅助术前评估和术中导航。结果    21例病人术中均成功应用混合现实技术，其中18例行根治性肿瘤切除，3例行腹腔探查、肿瘤活检手术，手术时间为210（40~580）min，出血量为300（20~1700）mL，肿瘤最大径为13.2（5.9~40.0）cm，术后无大出血、肠吻合口漏、死亡等严重并发症发生。全息投影的虚拟三维模型图像清晰、稳定、直观的显示了肿瘤的大小、位置、与毗邻器官和血管的解剖关系，评价肿瘤侵犯邻近器官的敏感度和特异度分别为63.6%和70.0%，评价肿瘤侵犯邻近重要血管的敏感度和特异度分别为87.5%和84.6%。结论    混合现实技术能够清晰准确的投影原发性腹膜后肿瘤与毗邻血管和器官的解剖图像，为手术的精准实施提供了一种新的辅助方法。

关键词: 混合现实, 术前评估, 术中导航, 原发性腹膜后肿瘤