Robert Loving

Introduction. During surgical operations, greater understanding of a patient’s specific blood flow to an area and additional information allowing for a more complete understanding of the areas vasculature allows surgeons so make the most informed decision and produce better outcomes for their patients^1,2. Most methods of vessel visualization must be done post-operatively, such as angiograms performed in a catheter lab, or are imprecise and only give the surgeon qualitative data, such as ultrasound doppler². Indocyanine Green, and other fluorescent tracers, can be used intraoperatively to evaluate the integrity of vessels in a surgical field intraoperatively which allows for a reduction in complication rates and allows for improved post-operative outcomes. Indocyanine Green also has a very high LD50 relative to its concentration needed to effectively image vessels and is cleared quickly from the body which allows for easy adoption³. Methods. Indocyanine Green was analyzed in several observational studies both retrospectively and proactively to determine its effectiveness in application to several different surgical procedures^1,2,4. Historically fluorescent dyes were used mostly in ophthalmology for retinal procedures and only in the last couple of decades has been applied to other surgical specialties^1,5. Because of this now many studies are being done analyzing complication rates with and without using Indocyanine Green to aid in intraoperative decision making⁶. Results. Indocyanine Green has been shown to be effective at reducing complication rates and producing better outcomes for patients. One of the most common metrics used in these studies was whether or not a second surgery was necessary to fix a problem from the original surgery^1,5. When Indocyanine Green was used during an operation the need for a second surgery was consistently reduced by nearly 50%^2,4. This demonstrated the effectiveness of using Indocyanine Green. Indocyanine Green was also shown to be an extremely efficient and produced promising results when used to check anastomoses or blockages in flow, such as aneurysm operations^1,4,7. Conclusion. Indocyanine Green is a useful tool for visualizing blood flow intraoperatively. It is easy to learn and use and has relatively low toxicity levels leading to rapid adoption in a wide array of surgical specialties³. The use of Indocyanine Green intraoperatively as a means of checking for complications has produced favorable results and led to improved outcomes. Indocyanine Green has proven to be particularly efficacious when checking anastomoses or blockage of flow ^1,4,7.

1. Shibata Y, Kurihara S, Arai S, et al. Efficacy of Indocyanine Green Angiography on Microsurgical Subinguinal Varicocelectomy. J Invest Surg. 2017;30(4):247-251. doi:10.1080/08941939.2016.1236855
2. Chaturvedi A, Shukair SA, Le Rolland P, Vijayvergia M, Gunn JW, Subramanian H. Blood vessel detection, localization and estimation using a smart laparoscopic grasper: a Monte Carlo study. Biomed Opt Express. 2018;9(5):2027-2040. Published 2018 Apr 3. doi:10.1364/BOE.9.002027
3. Alander JT, Kaartinen I, Laakso A, et al. A Review of Indocyanine Green Fluorescent Imaging in Surgery. International Journal of Biomedical Imaging. 2012;2012:1-26. doi:10.1155/2012/940585.
4. Kim JC, Lee JL, Park SH. Interpretative Guidelines and Possible Indications for Indocyanine Green Fluorescence Imaging in Robot-Assisted Sphincter-Saving Operations. Dis Colon Rectum. 2017;60(4):376-384. doi:10.1097/DCR.0000000000000782
5. Pirie CG, Rogers TE, Dorshow RB. Effectiveness of MB-102, a novel fluorescent tracer agent, for conducting ocular angiography in dogs. Am J Vet Res. 2020;81(5):428-436. doi:10.2460/ajvr.81.5.428
6. Smithee W, Chakravarthi S, Epping A, et al. Initial Experience with Exoscopic-Based Intraoperative Indocyanine Green Fluorescence Video Angiography in Cerebrovascular Surgery: A Preliminary Case Series Showing Feasibility, Safety, and Next-Generation Handheld Form-Factor. World Neurosurg. 2020;138:e82-e94. doi:10.1016/j.wneu.2020.01.244
7. Tajsic T, Cullen J, Guilfoyle M, et al. Indocyanine green fluorescence video angiography reduces vascular injury-related morbidity during micro-neurosurgical clipping of ruptured cerebral aneurysms: a retrospective observational study. Acta Neurochir (Wien). 2019;161(11):2397-2401. doi:10.1007/s00701-019-04029-6