Eaton-Peabody Laboratories, Massachusetts Eye and Ear.
Department of Otology and Laryngology, Harvard Medical School.
Otol Neurotol. 2021 Jun 1;42(5):e598-e604. doi: 10.1097/MAO.0000000000003058.
Predicting the course of cranial nerve (CN) VII in the cerebellopontine angle (CPA) on preoperative imaging for vestibular schwannoma (VS) may help guide surgical resection and reduce complications. Diffusion MRI based tractography has been used to identify cranial nerve trajectory, but intraoperative validation of this novel approach is challenging. Currently, validation is based on operative report descriptions of the course of cranial nerves, but yields a simplified picture of the three-dimensional (3D) course of CN VII. In this study, we investigate the accuracy of tractography with detailed patient-specific 3D-printed VS tumors.
Retrospective case review.
Tertiary referral center.
Twenty adult VS surgical candidates.
We compared tractography with intraoperative 3D course of CN VII. The surgeons were blinded to tractography and drew the intraoperative course of the CN VII on a patient specific 3D-printed tumor model for detailed comparison with tractography.
Of 20 patients, one was excluded due to subtotal removal and inability to assess CN VII course. In the remaining 19 patients, 84% (16/19) tractography was successful. In 94% of tumors with tractography (15/16), the intraoperative description of CN VII course matched the tractography finding. The maximum distance, however, between tractography and intraoperative course of CN VII was 3.7 mm ± 4.2 mm.
This study presents a novel approach to CN VII tractography validation in VS. Although descriptions of CN VII intraoperatively match tractography, caution is warranted as quantitative measures suggest a clinically significant distance between tractography and CN VII course.
在桥小脑角（CPA）术前影像学检查中预测前庭神经鞘瘤（VS）颅神经VII 的走行，有助于指导手术切除并减少并发症。基于弥散磁共振成像的束追踪技术已被用于识别颅神经轨迹，但术中验证这种新方法具有挑战性。目前，验证基于手术报告中对颅神经走行的描述，但简化了颅神经 VII 的三维（3D）走行。在这项研究中，我们使用详细的患者特定 3D 打印 VS 肿瘤来研究束追踪的准确性。
回顾性病例研究。
三级转诊中心。
20 名成年 VS 手术候选者。
我们比较了束追踪与 CN VII 的术中 3D 走行。手术医生对束追踪结果不知情，并在患者特定的 3D 打印肿瘤模型上绘制 CN VII 的术中走行，以便与束追踪进行详细比较。
在 20 名患者中，1 名患者因部分切除和无法评估 CN VII 走行而被排除。在其余 19 名患者中，84%（16/19）的束追踪成功。在有束追踪的 19 个肿瘤中，94%（15/16）的肿瘤术中描述的 CN VII 走行与束追踪结果一致。然而，束追踪与 CN VII 术中走行的最大距离为 3.7mm ± 4.2mm。
本研究提出了一种新的方法来验证 VS 中 CN VII 的束追踪。尽管术中对 CN VII 的描述与束追踪结果相匹配，但需要谨慎，因为定量测量提示束追踪与 CN VII 走行之间存在显著的临床差异。
