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Background and study aims The pocket-creation method (PCM) is a novel strategy for endoscopic submucosal dissection (ESD). The aim of this study is to determine the efficacy of the PCM for colorectal laterally spreading tumors, non-granular type (LST-NG). Patients and methods The records of 126 consecutive patients with colorectal LST-NG who underwent ESD between April 2012 and July 2015 were retrospectively reviewed. Patients were divided into PCM (n = 73) and conventional method (CM) (n = 53) groups. Results The en bloc resection rate in the PCM group was significantly higher than in the CM group (100 % [73/73] vs. 92 % [49/53], P = 0.03). The en bloc resection rate with severe fibrosis was higher in the PCM group than in the CM group (100 % [3/3] vs. 60 % [3/5]). The R0 resection rate for the two groups was not statistically significantly different (93 % [68/73] vs. 91 % [48/53], P = 0.74). The perforation rate in the PCM group was lower than in the CM group although not statistically significantly less (0 % 0/73 vs. 4 % 2/53, P = 0.18). For lesions resected en bloc, dissection speed for the PCM group was significantly faster than for the CM group (median [IQR], 19 [13 –24] vs. 14 [10 – 22] mm2/min, P = 0.03). Conclusion ESD using PCM achieves a reliable and safe resection of colorectal LST-NG.

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White light imaging (WLI) may not reveal early upper gastrointestinal cancers. Linked color imaging (LCI) produces bright images in the distant view and is performed for the same screening indications as WLI. LCI and blue laser imaging (BLI) provide excellent visibility of gastric cancers in high color contrast with respect to the surrounding tissue. The characteristic purple and green color of metaplasias on LCI and BLI, respectively, serve to increase the contrast while visualizing gastric cancers regardless of a history of Helicobacter pylori eradication.LCI facilitates color-based recognition of early gastric cancers of all morphological types, including flat lesions or those in an H. pylori-negative normal background mucosa as well as the diagnosis of inflamed mucosae including erosions. LCI reveals changes in mucosal color before the appearance of morphological changes in various gastric lesions. BLI is superior to LCI in the detection of early esophageal cancers and abnormal findings of microstructure and microvasculature in close-up views of upper gastrointestinal cancers. Excellent images can also be obtained with transnasal endoscopy. Using a combination of these modalities allows one to obtain images useful for establishing a diagnosis. It is important to observe esophageal cancers (brown) using BLI and gastric cancers (orange) surrounded by intestinal metaplasia (purple) and duodenal cancers (orange) by LCI.

Conventional endoscopy can miss flat early gastric cancers (0-IIb) because they may not be visible. We treated a patient with synchronous flat early gastric cancers missed by conventional white-light endoscopy (WLE). A 74-year-old Japanese male was referred for endoscopic submucosal dissection (ESD) of a depressed-type early gastric cancer (0-IIc) on the posterior wall of the antrum. Linked color imaging (LCI) detected two flat reddish lesions (0-IIb) measuring 30 mm and 10 mm in diameter in the distal body and prepyloric area, respectively, which had not been detected by conventional WLE. LCI clearly demonstrated the line of demarcation between the malignant lesion and the surrounding mucosa without magnification. Flat early gastric cancers were suspected because both lesions had irregular surface patterns using magnifying blue laser imaging (BLI). An additional depressed lesion (0-IIc) was detected by laser WLE along the greater curvature in the antrum. Magnifying BLI suggested a malignant lesion. Histological examination of biopsy specimens revealed atypical glands in all four lesions. ESD of these lesions was performed. Pathological examination of the resected specimens confirmed well-differentiated adenocarcinoma localized to the mucosa in all four lesions. Flat early gastric cancers became clearly visible using new endoscopic technology.