The LIver SEntinel LYmph-node (LISELY) study: A prospective intraoperative real time evaluation of liver lymphatic drainage and sentinel lymph-node using near-infrared (NIR) imaging with Indocyanine Green (ICG)

Real-Time Navigation in Liver Surgery Through Indocyanine Green Fluorescence: An Updated Analysis of Worldwide Protocols and Applications

BACKGROUND

Indocyanine green (ICG) fluorescence has seen extensive application across medical and surgical fields, praised for its real-time navigation capabilities and low toxicity. Initially employed to assess liver function, ICG fluorescence is now integral to liver surgery, aiding in tumor detection, liver segmentation, and the visualization of bile leaks. This study reviews current protocols and ICG fluorescence applications in liver surgery, with a focus on optimizing timing and dosage based on clinical indications.

METHODS

Following PRISMA guidelines, we systematically reviewed the literature up to 27 January 2024, using PubMed and Medline to identify studies on ICG fluorescence used in liver surgery. A systematic review was performed to evaluate dosage and timing protocols for ICG administration.

RESULTS

Of 1093 initial articles, 140 studies, covering a total of 3739 patients, were included. The studies primarily addressed tumor detection (40%), liver segmentation (34.6%), and both (21.4%). The most common ICG fluorescence dose for tumor detection was 0.5 mg/kg, with administration occurring from days to weeks pre-surgery. Various near-infrared (NIR) camera systems were utilized, with the PINPOINT system most frequently cited. Tumor detection rates averaged 87.4%, with a 10.5% false-positive rate. Additional applications include the detection of bile leaks, lymph nodes, and vascular and biliary structures.

CONCLUSIONS

ICG fluorescence imaging has emerged as a valuable tool in liver surgery, enhancing real-time navigation and improving clinical outcomes. Standardizing protocols could further enhance ICG fluorescence efficacy and reliability, benefitting patient care in hepatic surgeries.

[Preliminary results of fluorescent lymphography in patients with biliary cancer undergoing liver resection]

OBJECTIVE

To evaluate the diagnostic capability of intraoperative fluorescence lymphography (FLG) in detecting of sentinel lymph nodes (SLN) and lymph outflow pathways in patients with biliary cancer (BC).

MATERIAL AND METHODS

From April 2023 till March 2024, ten liver resections for BC were performed using FLG. We carried out the standard lymph node dissection with additional removal of lymph nodes (LN) that have accumulated indocyanine green (ICG). The lymphatic outflow pathways in all patients and frequency of SLN invasion were evaluated.

RESULTS

Ten patients were included: five patients had been diagnosed with intrahepatic cholangiocarcinoma (IHCC), two - with perichilar tumor (PT), the last three ones had gallbladder cancer (GBC). SLN No. 1 were detected in eight patients, the accumulation of ICG was detected in the following groups of LN: No. 8 (n=2), No. 13 (n=1), No. 12b (n=2), cystic lymph node (n=2), and No. 7 (n=1). SLN No. 2 was detected in seven patients. In three cases LN No. 13 were stained, in one - LN No. 12a, in another - LN No. 8. In two patients, staining of vesicular LN was noted. The combined morphological assessment of SLN No. 1 and SLN No. 2 made it possible to predict the presence of LN metastases in all patients (100%, n=3). Fluorescence of third-order LN was detected in four patients. In one case, the staining of LN No. 13 was noted. Another patient revealed accumulation of ICG in LN No. 3. In two cases, at the third stage, fluorescence of LN No. 7 was noted, while metastatic invasion of LN No. 7 was detected in one patient with IHCC.

CONCLUSION

Using FLG, it was possible to determine an alternative lymph flow outpath to LN No. 7 in three patients. The method allowed to identify and remove metastatic LN No. 7 in one case. 100% sensitivity was shown in the determination of SLN in BC in a small group of patients. It is advisable to study the sensitivity of the method in large-scale studies.

Indocyanine Green and Hepatobiliary Surgery: An Overview of the Current Literature

Indocyanine green (ICG) is an inert polypeptide that almost totally binds to high molecular weight plasma proteins; it is cleared by the hepatocytes and directly excreted into the bile with a half-life of about 3-5 minutes. Specific systems are required to see fluorescent images. The use of this dye has been reported in different surgical specialties, and the applications in hepatobiliary surgery are widening. Being firstly used to evaluate the preoperative liver function, intra- and postoperative dynamic checking of hepatic activity has been reported and integrated within perioperative protocols allowing a tailored treatment allocation. Intravenous injection (IV) or injection into the gallbladder can ease difficult cholecystectomy. Biliary leakage detection could be enhanced by IV ICG injection. Although with some contrasting results, the use of ICG for both delineating the limits of the resection and tumor-enhanced visualization was demonstrated to improve short- and long-term outcomes. Although the lack of strong evidence still precludes the introduction of this tool in clinical practice, it harbors great potential in liver surgery.

Nano-tracers for sentinel lymph node detection: current trends in technique and application

Sentinel lymph node (SLN) detection and biopsy is a critical staging component for several cancers. Apart from established methods using dyes or radiolabeled colloids, newer techniques are emerging, like near-infrared fluorescent compounds, targeted molecular radiopharmaceuticals and magnetic nano-tracers. In the overview section of this review, we categorize SLN detection tracers based on their principle of use. We discuss the merits of existing tracers and provide a glimpse of in-development formulations. A subsequent clinical section explores the expanded role of SLN detection in management of various cancers, citing current medical guidelines and the leading conclusions of long-term clinical trials. The concluding section tries to provide a perspective of promising developments and the work required to bring them to clinical fruition.