Goda Y¹, Mori H¹, Kobara H¹, Nishiyama N¹, Kobayashi N¹, Yachida T¹, Masaki T¹.

Endoscopy. 2017 Oct 17. doi: 10.1055/s-0043-119984. [Epub ahead of print]

Linked color imaging (LCI; Fujifilm Co., Tokyo, Japan) is a newly developed image- enhanced technique that has shown high diagnostic performance in the field of gastrointestinal endoscopy. LCI enhances color separation of the mucosal layer, making red regions redder and white regions whiter. This contributes to the detection of gastric cancer [1], ulcerative colitis [2], colorectal polyps [3, 4], and other lesions. Although the diagnostic productivity is steadfast, the treatment benefit of LCI remains unclear or limited [5]. We herein introduce an advantage of LCI with respect to increasing the safety of endoscopic mucosal resection (EMR), illustrating the efficacy of LCI in the treatment field.

Compared with white-light imaging, narrow- band imaging, and bright-light imaging, the view of the blood vessels in the superficial layer is much more conspicuous when obtained by LCI. When performing EMR, local injection is the first crucial step and the basis of later procedures such as polyp removal by snaring. However, injury to the superficial vessels invisible with white light sometimes induces hematoma formation, making subsequent snaring difficult (▶Fig. 1 a). LCI can more precisely reveal the running of the superficial vessels around a colorectal polyp than can white light imaging (▶Fig. 1 b) and bright-light imaging (▶Fig. 1 c). LCI enhances the reddish, glaring characteristics of the vessels, pinpointing safe sites for needling (▶Fig. 1 d). Consequently, the clinician can avoid needling blood vessels near the polyp (▶Fig. 1 e) and prevent unnecessary bleeding and hematoma formation (▶Fig. 1 f), leading to secure completion of EMR.

White-light imaging, bright-light imaging, and LCI for EMR local injections are compared in ▶Video 1. Only LCI shows the reddish network pattern of the superficial blood vessels. This leads to sufficient swelling of the submucosal layer and appropriate removal of colorectal polyps.

Fig. 1 Endoscopic images illustrating the advantages of linked color imaging (LCI) during endoscopic mucosal resection. a Improper injection can induce hematoma formation. b Superficial vessels around a colorectal polyp are invisible with white-light imaging. c Superficial vessels are also unclear with bright-light imaging. d LCI shows the orientation of vessels around the polyp. e The injection needle pinpoints a site lacking vessels. f Unnecessary hematoma formation and bleeding can be avoided during mucosal injection.

Video 1 White-light imaging only ambiguously shows the blood vessel routes, whereas linked color imaging (LCI) indicates the vessels clearly as a vivid reddish color. From injection to snaring, LCI allows the clinician to avoid unnecessary bleeding.

¹Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan.

Kono Y¹, Kawahara Y², Okada H¹.

Clin Gastroenterol Hepatol. 2017 Sep 1. pii: S1542-3565(17)31045-5.

Chromoendoscopy (CE) and image-enhanced endoscopy are useful for accurately diagnosing gastric neoplasms. However, unclear lesions, such as those with a flat morphology or normochromic color, sometimes can be missed. We herein present a case in which CE was performed with the combined use of an acetic acid indigo carmine mixture (AIM) and linked-color imaging (LCI), and this method was effective for detecting early gastric cancer. A Japanese man in his 70s underwent esophagogastroduodenoscopy for screening purposes. It was difficult to identify any lesions by white-light imaging (Figure A).

However, when performing image-enhanced endoscopy with LCI, a shallow depressed lesion was identified in the prepyloric area and this modality made it easier to detect the lesion, but the visibility was insufficient to distinguish clearly between the lesion and the surrounding area (Figure B). CE using an AIM with LCI enhanced not only the surface color, but also the demarcation line of the lesion (Figure C). A histologic examination of a biopsy specimen showed differentiated-type adenocarcinoma, and endoscopic submucosal dissection thereafter was performed.

The pathologic diagnosis of the resected specimen showed well-differentiated adenocarcinoma of the stomach (Figure D). Performing CE using an AIM and LCI is useful for detecting gastric neoplasms.