目的:探讨混合现实技术在口腔颌面部肿瘤手术中的应用价值。方法:选择2018年12月—2020年1月就诊于北京大学口腔医院口腔颌面外科需行手术治疗的肿瘤患者,将患者术前增强CT原始数据导入星图医学影像工作站(维卓致远,中国北京),分别对肿瘤、血管、骨骼等重要解剖结构进行三维模型重构,显示其术前空间关系,对重点结构进行标记,并进行术前规划。通过混合现实技术在术区立体显示三维重建模型,术者利用简单手势在术中保持无菌状态下对眼前的三维重建模型进行调整,观察肿瘤范围、大小、位置及其与周围临近重要解剖结构的关系。应用混合现实技术辅助手术进行,手术开始前进行三维模型配准,肿瘤显露过程中进行术中验证,术后利用Likert量表对混合现实技术的应用效果进行评价。结果:入选的8例患者均顺利实施了混合现实技术辅助下的肿瘤切除手术,手术过程中三维重建模型平均配准时间为12.0 min,术者在所有病例的手术中均都能直观、立体地观看肿物以及周围解剖结构的三维重建模型,并可在术中自行调整图像。Likert量表评价结果显示:在感知准确性、帮助确定解剖部位、术中图像引导作用,以及改善手术安全性的潜力方面均获得较高评分(分别为4.22、4.19、4.16和4.28分)。8例患者术后愈合良好,无手术并发症发生。结论:混合现实技术能通过三维重建模型实时立体可视化,提供术区解剖结构信息,引导和修正手术操作,提高口腔颌面部肿瘤切除手术的准确性和安全性。

Objective: To explore the application of mixed reality technique for the surgery of oral and maxillofacial tumors. Methods: In this study, patients with a diagnosis of an oral and maxillofacial tumor who were referred to Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from December 2018 to January 2020 were selected. The preoperative contrast-enhanced computed tomography data of the patients were imported into StarAtlas Holographic Medical Imaging System (Visual 3D Corp., Beijing, China). Three-dimensional (3D) model of tumor and key structures, such as skeleton and vessels were reconstructed to three-dimensionally present the spatial relationship between them, followed with the key structures delineation and preoperative virtual surgical planning. By using mixed reality technique, the real-time 3D model was displayed stereotactically in the surgical site. While keeping sterile during operation, the surgeon could use simple gestures to adjust the 3D model, and observed the location, range, and size of tumor and the key structures adjacent to the tumor. Mixed reality technique was used to assist the operation: 3D model registration was performed for guidance before tumor excision; intraoperative real-time verification was performed during tumor exposure and after excision of the tumor. The Likert scale was used to evaluate the application of mixed reality technique after the operation. Results: Eight patients underwent mixed reality assisted tumor resection, and all of them successfully completed the operation. The average time of the 3D model registration was 12.0 minutes. In all the cases, the surgeon could intuitively and three-dimensionally observe the 3D model of the tumor and the surrounding anatomical structures, and could adjust the model during the operation. The results of the Likert scale showed that mixed reality technique got high scores in terms of perceptual accuracy, helping to locate the anatomical parts, the role of model guidance during surgery, and the potential for improving surgical safety (4.22, 4.19, 4.16, and 4.28 points respectively). Eight patients healed well without perioperative complications. Conclusion: By providing real-time stereotactic visualization of anatomy of surgical site and guiding the operation process through 3D model, mixed reality technique could improve the accuracy and safety of the excision of oral and maxillofacial tumors.