Confocal laser endomicroscopy enables in vivo microscopic observation during ongoing endoscopy by using the fluorescent confocal imaging technique. There have been endoscopy-based, probe-based, and needle-based confocal laser endomicroscopes, but the endoscopy-based scope is no longer available. Probe- and needle-based confocal laser endomicroscopy can be applied to various organs such as the biliary and pancreatic ducts, liver, bronchial tubes and alveoli, urinary bladder, and thyroid gland. Fluorescent agents can be administered in two ways including intravenous injection and intraluminal spraying. Confocal laser endomicroscopy enables not only microscopic observation but also functional and molecular imaging. In this article, we describe the mechanism of confocal laser endomicroscopy, its specifications, observation method, and characteristics, and introduce various fields of application in addition to actual images.

A 75-year-old man with thoracic esophageal cancer received preoperative chemotherapy. After the first course of chemotherapy, he developed fever, cervical swelling and pain. Computed tomographic scan revealed a mediastinal abscess extending to a retropharyngeal abscess. Since there was no clinical improvement with conservative therapy, endoscopic ultrasound (EUS)-guided transesophageal drainage of the mediastinal abscess was performed, which subsequently led to resolution of the abscess. This is the first report of a case with mediastinal abscess treated by EUS-guided transesophageal drainage in Japan.

White globe appearance (WGA) has recently been identified as an endoscopic marker that is useful for diagnosing early gastric carcinoma. However, the clinical efficacy of WGA for diagnosing noncancerous lesions remains unclear. Here, we describe a patient with type A gastritis in whom several WGAs were detected. Several white spots were visually captured on the atrophic mucosa under white light imaging, indicating that WGAs can be observed under magnifying endoscopy with narrow band imaging. The biopsy specimen obtained from a white spot revealed histologically eosinophilic material with necrotic fragments in the dilated gland, demonstrating intra-glandular necrotic debris. This case provides multidisciplinary information for investigating the clinical significance of WGAs in noncancerous lesions.

A 70-year-old male was referred to our department due to melena which began one month previously. Esophagogastroduodenoscopy and colonoscopy were performed, but no signs of active bleeding were found. Therefore, capsule endoscopy was performed to check for small intestinal lesions. Capsule endoscopy revealed multiple protruded lesions and bloody intestinal fluid in a lesion in the upper ileum. Double-balloon enteroscopy revealed multiple protruded lesions suspicious of being hemangioma. Endoscopic mucosal resection of a lesion was performed, and it was finally diagnosed as capillary hemangioma. Sclerotherapy was performed by injecting polidocanol in the multiple hemangiomas. After this treatment, there was no melena and the follow-up endoscopy showed decreased size of the lesions. Thus, sclerotherapy was found to be useful in the treatment of multiple hemangiomas in the small intestine.

Endoscopic injection sclerotherapy (EIS) and variceal ligation (EVL) for esophageal varices are the standard treatments for prevention of esophageal varices bleeding. On the other hand, these treatments for varices may induce the development of ectopic varices. Ectopic varices are rare, but have a higher risk of bleeding. Among the ectopic varices, bile duct varix is extremely rare. However, patients with bile duct varix are at risk for jaundice as well as bleeding. Extra-hepatic portal obstruction is often complicated with bile duct varices as collateral circulations, and EIS may increase the intravessel pressure of the bile duct varices and compress the bile duct. We report two patients who developed obstructive jaundice after EIS. Case 1: A 21-year-old male developed idiopathic extra-hepatic portal thrombosis. Three years later, EIS was performed for esophageal varices with red color signs. After EIS, he developed obstructive jaundice. Cholangiography showed multiple compressions due to biliary varices at the distal and intra-hepatic bile ducts. The patient requires continuous endoscopic biliary stenting. Case 2: The female patient has a congenital extra-hepatic portal obstruction. EIS and EVL were performed for esophageal varices with red color signs at 18 years of age, and she developed obstructive jaundice 12 years after EIS. Cholangiography showed multiple compressions due to biliary varices at the distal and intra-hepatic bile ducts. Endoscopic biliary stenting was performed. Five months after biliary stenting, she developed re-exacerbation of esophageal varices and EIS was performed again. After the second EIS procedure, stenosis of the distal bile duct worsened and she required continuous endoscopic biliary drainage. In conclusion, in cases with esophageal varices associated with extra-hepatic portal obstruction, the treatment for esophageal varices should be decided very carefully while paying attention to the biliary varices.

The ampulla of Vater (ampulla) has anatomical features that are not found in other portions of the gastrointestinal tract. The ampulla of Vater is formed by the union of the pancreatic duct and the common bile duct. Although consensus is being obtained for local excision including endoscopic ampullectomy for the treatment of adenomas that do not extend into the biliary and pancreatic ducts, pancreatoduodenectomy is basically recommended for the treatment of adenocarcinoma because of the difficulty in diagnosis of invasion into the sphincter of Oddi. It is also problematic that the pathological diagnosis of biopsy samples and that of resected samples are often different. The indication of endoscopic ampullectomy has to be determined by considering the findings of endoscopy, endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS). We will illustrate the actual diagnostic procedure of ampullary tumors (adenoma and adenocarcinoma) focusing on the indication of endoscopic ampullectomy.

Computed tomographic colonography (CTC) can be considered to be the best radiological test for the diagnosis of colorectal cancer. CTC can be used for both diagnostic and screening applications in colorectal cancer as a complementary examination to colonoscopy. Reading of CTC examinations should include endoluminal three-dimensional (3D) as well as two-dimensional (2D) planar view images. Primary 3D endoluminal fly-through reading is evaluated using 2D images for confirmation and characterization of any potential findings. The primary 2D reading technique is based on lumen tracking in which the physician interactively tracks the course of the distended colonic lumen from the rectum to the cecum. The primary 2D technique is performed with additional endoluminal 3D virtual endoscopic views for problem-solving. Evidence-based reading is mandatory for quality control of CTC.

The Questionnaire on the Education and Training System for Female Trainee Endoscopists was sent to 4,281 female members of the Japan Gastroenterological Endoscopy Society. Only 169 members filled out the questionnaire. Fourteen percent of the respondents have taken continuing education and training courses. For female trainee endoscopists, it is difficult to attend continuing education and training courses due to family obligations. Opportunities to attend continuing education and training courses that provide a support structure for female endoscopists have to be increased in Japan.

Background and Aim: Safety and effectiveness of cold snare polypectomy (CSP) compared with hot snare polypectomy (HSP) has been reported. The aim of the present study is to carry out a meta-analysis of the efficacy and safety of HSP and CSP.

Methods: Randomized controlled trials were reviewed to compare HSP with CSP for resecting small colorectal polyps. Outcomes reviewed include complete resection rate, polyp retrieval, delayed bleeding, perforation and procedure time. Outcomes were documented by pooled risk ratios (RR) with 95% confidence intervals (CI) using the Mantel-Haenszel random effect model.

Results: Eight studies were reviewed in this meta-analysis, including 1665 patients with 3195 polyps. Complete resection rate using HSP was similar to CSP (RR: 1.02, 95% CI: 0.98-1.07, P = 0.31). Polyp retrieval after HSP was similar to CSP (RR: 1.00, 95% CI: 1.00-1.01, P = 0.60). Delayed bleeding rate after HSP was higher than after CSP, although not significantly (patient basis: RR: 7.53, 95% CI: 0.94-60.24, P = 0.06; polyp basis: RR: 7.35, 95% CI: 0.91-59.33, P = 0.06). Perforation was not reported in all eight studies. Total colonoscopy time for HSP was significantly longer than CSP (mean difference 7.13 min, 95% CI: 5.32-8.94, P < 0.001). Specific polypectomy time for HSP was significantly longer than CSP (mean difference 30.92 s, 95% CI: 9.15-52.68, P = 0.005).

Conclusion: This meta-analysis shows significantly shorter procedure time using CSP compared with HSP. CSP tends toward less delayed bleeding compared with HSP. We recommend CSP as the standard treatment for resecting small benign colorectal polyps.