German Cancer Research Center (DKFZ), Heidelberg, Germany.
National Center for Tumor Diseases (NCT/UCC), Dresden, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany; Medizinische Fakultät and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
J Biomed Opt. 2023 Sep;28(9):094803. doi: 10.1117/1.JBO.28.9.094803. Epub 2023 May 12.
Cerebrospinal fluid (CSF) rhinorrhea (leakage of brain fluid from the nose) can be difficult to identify and currently requires invasive procedures, such as intrathecal fluorescein, which requires a lumbar drain placement. Fluorescein is also known to have rare but significant side effects including seizures and death. As the number of endonasal skull base cases increases, the number of CSF leaks has also increased for which an alternative diagnostic method would be highly advantageous to patients.
We aim to develop an instrument to identify CSF leaks based on water absorption in the shortwave infrared (SWIR) without the need of intrathecal contrast agents. This device needed to be adapted to the anatomy of the human nasal cavity while maintaining low weight and ergonomic characteristics of current surgical instruments.
Absorption spectra of CSF and artificial CSF were obtained to characterize the absorption peaks that could be targeted with SWIR light. Different illumination systems were tested and refined prior to adapting them into a portable endoscope for testing in 3D-printed models and cadavers for feasibility.
We identified CSF to have an identical absorption profile as water. In our testing, a narrowband laser source at 1480 nm proved superior to using a broad 1450 nm LED. Using a SWIR enabling endoscope set up, we tested the ability to detect artificial CSF in a cadaver model.
An endoscopic system based on SWIR narrowband imaging can provide an alternative in the future to invasive methods of CSF leak detection.
脑脊液（CSF）鼻漏（脑液从鼻子漏出）很难识别，目前需要进行侵入性程序，例如鞘内荧光素检查，这需要放置腰椎引流管。荧光素也有罕见但严重的副作用，包括癫痫发作和死亡。随着经鼻颅底手术数量的增加，CSF 漏的数量也有所增加，因此，对于患者来说，替代诊断方法将非常有利。
我们旨在开发一种基于短波近红外（SWIR）水吸收的仪器来识别 CSF 泄漏，而无需鞘内对比剂。该设备需要适应人体鼻腔的解剖结构，同时保持当前手术器械的低重量和人体工程学特性。
获得 CSF 和人工 CSF 的吸收光谱，以表征可以用 SWIR 光靶向的吸收峰。在将它们适配到便携式内窥镜中进行 3D 打印模型和尸体的可行性测试之前，对不同的照明系统进行了测试和改进。
我们发现 CSF 的吸收谱与水完全相同。在我们的测试中，1480nm 的窄带激光源比使用 1450nm 的宽 LED 更优越。使用启用 SWIR 的内窥镜系统，我们测试了在尸体模型中检测人工 CSF 的能力。
基于 SWIR 窄带成像的内窥镜系统将来可以替代 CSF 泄漏检测的侵入性方法。
