Fluorescence-guided surgery: comprehensive review

Abstract

Background: Despite significant improvements in preoperative workup and surgical planning, surgeons often rely on their eyes and hands during surgery. Although this can be sufficient in some patients, intraoperative guidance is highly desirable. Near-infrared fluorescence has been advocated as a potential technique to guide surgeons during surgery.

Methods: A literature search was conducted to identify relevant articles for fluorescence-guided surgery. The literature search was performed using Medical Subject Headings on PubMed for articles in English until November 2022 and a narrative review undertaken.

Results: The use of invisible light, enabling real-time imaging, superior penetration depth, and the possibility to use targeted imaging agents, makes this optical imaging technique increasingly popular. Four main indications are described in this review: tissue perfusion, lymph node assessment, anatomy of vital structures, and tumour tissue imaging. Furthermore, this review provides an overview of future opportunities in the field of fluorescence-guided surgery.

Conclusion: Fluorescence-guided surgery has proven to be a widely innovative technique applicable in many fields of surgery. The potential indications for its use are diverse and can be combined. The big challenge for the future will be in bringing experimental fluorophores and conjugates through trials and into clinical practice, as well as validation of computer visualization with large data sets. This will require collaborative surgical groups focusing on utility, efficacy, and outcomes for these techniques.

Fig. 1

Example of near-infrared fluorescence perfusion imaging using indocyanine green during preparation of a gastric conduit after oesophagectomy, demonstrating a tapering in the degree of perfusion a White light image. b Near-infrared fluorescence image. c Colour-NIR merge image. d Subsequent regions of interest are drawn to plot time–intensity curves. e Time–intensity curves based on absolute fluorescent signal. f Time–intensity curves based on normalized curves.

Fig. 2

Overview of clinical applications of fluorescence-guided surgery in colorectal, hepatopancreatobiliary, and endocrine surgery Indocyanine green and methylene blue are commercially available fluorescent probes with applications in these patients. Specific dosing and dose timing for the indications above are described fully in the main text. Created using BioRender.com. ICG, indocyanine green; MB, methylene blue; SLN, sentinel lymph node.

Fig. 3

Illustrative example of the application of computer vision and artificial intelligence methods to indocyanine green fluorescence angiography for the classification of rectal cancer The images to the left show the white light endoscopic appearance of a rectal tumour above a still of the dynamic indocyanine green perfusion phase of the same lesion. Indocyanine green intensity time series from the boxed areas in these images allow prediction (including mathematical probability) of whether the lesion is cancerous or not based on rapid statistical inference of such time-series analyses. ROI, region of interest.