1Department of Neurosurgery, University Hospital Münster; and.
2Karl Storz GmbH & Co., Tuttlingen,Germany.
J Neurosurg. 2018 Feb;128(2):399-405. doi: 10.3171/2016.11.JNS161072. Epub 2017 Mar 24.
OBJECTIVE Fluorescence guidance with 5-aminolevulinic acid (5-ALA) helps improve resections of malignant gliomas. However, one limitation is the low intensity of blue light for background illumination. Fluorescein has recently been reintroduced into neurosurgery, and novel microscope systems are available for visualizing this fluorochrome, which highlights all perfused tissues but has limited selectivity for tumor detection. Here, the authors investigate a combination of both fluorochromes: 5-ALA for distinguishing tumor and fluorescein for providing tissue fluorescence of adjacent brain tissue. METHODS The authors evaluated 6 patients who harbored cerebral lesions suggestive of high-grade glioma. Patients received 5-ALA (20 mg/kg) orally 4 hours before induction of anesthesia. Low-dose fluorescein (3 mg/kg intravenous) was injected immediately after anesthesia induction. Pentero microscopes (equipped either with Yellow 560 or Blue 400 filters) were used to visualize fluorescence. To simultaneously visualize both fluorochromes, the Yellow 560 module was combined with external blue light illumination (D-light C System). RESULTS Fluorescein-induced fluorescence created a useful background for protoporphyrin IX (PPIX) fluorescence, which appeared orange to red, surrounded by greenly fluorescent normal brain and edematous tissue. Green brain-tissue fluorescence was helpful in augmenting background. Levels of blue illumination that were too strong obscured PPIX fluorescence. Unspecific extravasation of fluorescein was noted at resection margins, which did not interfere with PPIX fluorescence detection. CONCLUSIONS Dual labeling with both PPIX and fluorescein fluorescence is feasible and gives superior background information during fluorescence-guided resections. The authors believe that this technique carries potential as a next step in fluorescence-guided resections if it is completely integrated into the surgical microscope.
荧光引导下使用 5-氨基酮戊酸（5-ALA）有助于提高恶性胶质瘤的切除率。然而，其存在一个局限性，即用于背景照明的蓝光强度较低。荧光素最近已重新引入神经外科，并且有新型显微镜系统可用于可视化这种荧光染料，该染料可突出所有灌注组织，但对肿瘤检测的选择性有限。在此，作者研究了两种荧光染料的组合：5-ALA 用于区分肿瘤，荧光素用于提供邻近脑组织的组织荧光。
作者评估了 6 例存在疑似高级别胶质瘤脑病变的患者。患者在麻醉诱导前 4 小时口服 5-ALA（20mg/kg）。麻醉诱导后立即静脉注射低剂量荧光素（3mg/kg）。作者使用 Pentero 显微镜（分别配备 Yellow 560 或 Blue 400 滤波器）来可视化荧光。为了同时可视化两种荧光染料，将 Yellow 560 模块与外部蓝光照射（D-light C System）相结合。
荧光素诱导的荧光为原卟啉 IX（PPIX）荧光创造了有用的背景，PPIX 荧光呈橙色至红色，周围是绿色荧光的正常脑组织和水肿组织。绿色脑组织荧光有助于增强背景。过强的蓝色照明水平会使 PPIX 荧光模糊。在切除边缘处注意到荧光素的非特异性外渗，但这并未干扰 PPIX 荧光的检测。
同时对 PPIX 和荧光素荧光进行双重标记是可行的，并且在荧光引导下切除过程中可提供更好的背景信息。作者认为，如果该技术完全集成到手术显微镜中，它可能成为荧光引导下切除的下一步。
