A new fluorescence imaging technique for visualizing hepatobiliary structures using sodium fluorescein: result of a preclinical study in a rat model

Laparoscopic fluorescence imaging technique for visualizing biliary structures using sodium fluorescein: the result of a preclinical study in a porcine model

Purpose

Near-infrared fluorescence imaging has been recently applied in the field of hepatobiliary surgery. Our objective was to apply blue-light fluorescence cholangiography during laparoscopic surgery. Therefore, we designed a preclinical study to evaluate the feasibility of using blue-light fluorescence for cholangiography in a porcine model.

Methods

Five millimeters of sodium fluorescein (SF) solution was administered into the gallbladder of 20 male 3-way crossbred (Landrace × Yorkshire × Duroc) pigs in laparoscopic approach. The biliary tree was observed under blue light (a peak wavelength of 450 nm) emitted from a commercialized light-emitting diode (LED) light source (XLS1 extreme, Chammed).

Results

In 18 of 20 porcine models, immediately after SF solution was administered into the gallbladder, it was possible to visualize the biliary tree under blue light emitted from the LED light source.

Conclusion

This study provided a preclinical basis for using blue-light fluorescence cholangiography using SF in laparoscopic surgery. The clinical feasibility of blue-light fluorescence imaging techniques for laparoscopic cholecystectomy remained to be demonstrated.

Laparoscopic Liver Resection Enhanced by an Intervention-Guided Fluorescence Imaging Technique Using Sodium Fluorescein

BACKGROUND AND OBJECTIVES

In laparoscopic liver resections, tumor localization is a critical aspect of ensuring clear resection margins and preserving the hepatic parenchyma. In this study, we designed a fluorescence imaging technique using a new fluorophore for tumor localization.

MATERIALS AND METHODS

Immediately before laparoscopic or transthoracic liver resection, microcatheter was inserted through the hepatic artery and used to engrave the segment containing the tumor in the intervention room. Under blue light, the fluorescence of the lesion was visually confirmed, and the location was determined through intraoperative sonography. After tumor localization, liver resection was performed.

RESULTS

From February 2017 to March 2020, 24 patients underwent laparoscopic liver resection (LLR) or video-assisted transthoracic liver resection (VTLR) using intervention-guided fluorescence imaging technique (IFIT).

CONCLUSIONS

IFIT can provide some advantages in the field of LLR. In addition, in cases of VTLR for hepatocellular carcinoma in the superior posterior segment in patients with marginal liver function, IFIT is considered useful.

Innovative treatment for hepatocellular carcinoma (HCC)

Indocyanine green (ICG) is not new in the field of liver surgery. Early studies performed in the 1980s and 1990s revealed the value of the ICG clearance test in predicting post-hepatectomy morbidity and mortality. ICG clearance and retention tests are crucial for determining precise liver function before liver surgery and offer several benefits for safe surgery. Whereas ICG is well-known and has long history in medicine, recent progress in infrared light technology over the last decade has highlighted another feature of ICG. For example, ICG fluorescence-guided surgery may change the next generation of liver surgery. In the near future, ICG with near-infrared (NIR) light photodynamic therapy (PDT) is expected to become a new treatment method for hepatocellular carcinoma (HCC). Furthermore, several aspects of the mechanisms of ICG accumulation in HCC cells have been revealed by important basic research studies. New imaging technologies and mechanistic findings keep ICG in the spotlight. In this article, we review three recently described topics of ICG which may contribute to the development of innovative and new treatments method for HCC, fluorescence-guided surgery, mechanism of ICG accumulation in HCC cells, PDT for HCC.