Ebihara Yuma, Li Liming, Noji Takehiro, Kurashima Yo, Murakami Soichi, Shichinohe Toshiaki, Hirano Satoshi
Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine; Division of Minimally Invasive Surgery, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
Department of Bio-material, Graduate School of Photonics Science, Chitose Institute of Science and Technology, Chitose, Hokkaido, Japan.
J Minim Access Surg. 2022 Jan-Mar;18(1):125-128. doi: 10.4103/jmas.JMAS_165_20.
Near-infrared (NIR) fluorescence image-guided surgery (FIGS) introduces a revolutionary new approach to address this basic challenge in minimally invasive surgery. However, current FIGS systems have some limitations - the infrared rays cannot detect and visualise thick tissues with low concentrations of the fluorescent agent. We established a novel laparoscopic fluorescence spectrum (LFS) system using indocyanine green (ICG) fluorescence to overcome these limitations.
Bovine serum albumin (BSA) was conjugated to ICG, and the mixtures were serially diluted at 5 × 10-5 × 10 mg/mL. We used the LFS system and a NIR camera system (NLS; SHINKO OPTICAL CO., LTD Tokyo, Japan) to determine the optical dilution for the fluorescence detection. BSA was conjugated to ICG (5.0 × 10 mg/mL) and used to coat the clips. We attempted to identify the fluorescence-coated clip from the serosal side of the cadaveric porcine stomach tissues using the LFS system and the NIR camera system. We measured the depth of the cadaveric porcine stomach wall at the thickest part that could be confirmed.
We could not visualise fluorescence concentrations <2.5 × 10 mg/mL using the NIR camera system. The spectrum was detected at a concentration <2.5 × 10 mg/mL. We were able to identify the spectrum of ICG (829 nm) to a 13-mm depth of cadaveric porcine stomach wall by using the LFS system but could not identify the same with the NIR camera system regardless of wall thickness.
The novel LFS system with NIR fluorescence imaging in this ex vivo and cadaveric porcine model was confirmed useful at deeper depths and lower concentrations. Based on these findings, we anticipate that the LFS system can be integrated and routinely used in minimally invasive surgery.
近红外（NIR）荧光图像引导手术（FIGS）引入了一种革命性的新方法，以应对微创手术中的这一基本挑战。然而，当前的FIGS系统存在一些局限性——红外线无法检测和可视化低浓度荧光剂的厚组织。我们建立了一种使用吲哚菁绿（ICG）荧光的新型腹腔镜荧光光谱（LFS）系统来克服这些局限性。
将牛血清白蛋白（BSA）与ICG偶联，并将混合物以5×10 - 5×10 mg/mL的浓度进行系列稀释。我们使用LFS系统和近红外相机系统（NLS；日本东京新光光学株式会社）来确定荧光检测的光学稀释度。将BSA与ICG（5.0×10 mg/mL）偶联并用于包裹夹子。我们试图使用LFS系统和近红外相机系统从猪尸体胃组织的浆膜侧识别荧光包裹的夹子。我们测量了猪尸体胃壁最厚部分可确认的深度。
使用近红外相机系统无法可视化浓度<2.5×10 mg/mL的荧光。在浓度<2.5×10 mg/mL时检测到光谱。通过使用LFS系统，我们能够识别出猪尸体胃壁13毫米深度处的ICG光谱（829纳米），但无论胃壁厚度如何，使用近红外相机系统均无法识别相同的光谱。
在这个离体和猪尸体模型中，具有近红外荧光成像的新型LFS系统在更深的深度和更低的浓度下被证实是有用的。基于这些发现，我们预计LFS系统可以集成并常规用于微创手术。
