Editorial The Beginning of a New Era of Digestive Surgery Guided by Fluorescence Imaging

There has been a dramatic increase in the use of fluorescence imaging for visualizing biological structures during surgery; a MEDLINE search with the keywords “fluorescence imaging ” and “surgery ” yielded year-on-year increases in the number of publications, which reached more than 1,200 articles in 2012 (fig. 1). Use of fluorescence imaging in surgical settings started at the beginning of the 21st century with angiography using indocyanine green (ICG) as a source of fluorescence during coronary artery bypass grafting [1], and this was followed by sentinel node navigation in breast cancer surgery [2] and intraoperative an-giography for cerebral aneurysm [3] in the mid 2000s. Since near-infrared imaging systems became commercially available for open surgery in 2005 and for laparoscopic surgery in 2011, the application of fluorescence-guided surgery has further accelerated. Among the numerous fluorescent probes available for in vivo imaging, ICG remains the mainstay in the clinical setting. The safety of ICG has been established over more than 50 years of clinical usage. Its fluorescent properties (excitation 750–810 nm, emission around 830 nm) mean that the signal is not absorbed by hemoglobin or water, which confers ad-vantages in visualizing deep-lying structures. In the field of hepatobiliary surgery, the fac