Kenshi Yao

Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer.

BACKGROUND The color change observed endoscopically in early gastric cancer is thought to correlate with vascular density and architecture. This study investigated the endoscopic microvascular architecture in intramucosal gastric carcinoma in vivo. METHODS Intramucosal gastric carcinomas without ulceration in 27 patients were studied by using a new magnifying upper endoscope with attention to microvascular findings. The carcinomas were divided into two major types histologically: differentiated (18) and undifferentiated (9). RESULTS A regular subepithelial capillary network was demonstrated in noncancerous mucosa. The appearance of the carcinomas differed depending on histologic differentiation. With all of the differentiated carcinomas, there was a well-demarcated area where the regular capillary pattern of noncancerous mucosa had disappeared and irregular microvessels were proliferating. In contrast, with undifferentiated carcinomas there was only an ill-defined area with disappearance or a reduction in the density of capillaries in the noncancerous mucosa. CONCLUSIONS Magnified endoscopic observation of microvessels may be of assistance in the identification of intramucosal gastric carcinomas that exhibit only subtle changes in color and shape at standard endoscopy.

Magnifying narrowband imaging is more accurate than conventional white-light imaging in diagnosis of gastric mucosal cancer.

BACKGROUND & AIMS It is difficult to accurately diagnose patients with depressed gastric mucosal cancer based on conventional white-light imaging (C-WLI) endoscopy. We compared the real-time diagnostic yield of C-WLI for small, depressed gastric mucosal cancers with that of magnifying narrow-band imaging (M-NBI). METHODS We performed a multicenter, prospective, randomized, controlled trial of patients with undiagnosed depressed lesions ≤10 mm in diameter identified by esophagogastroduodenoscopy. Patients were randomly assigned to groups that were analyzed by C-WLI (n = 176) or M-NBI (n = 177) immediately after detection; the C-WLI group received M-NBI after C-WLI. We compared the diagnostic accuracy, sensitivity, and specificity between C-WLI and M-NBI and assessed the diagnostic yield of M-NBI conducted in conjunction with C-WLI. RESULTS Overall, 40 gastric cancers (20 in each group) were identified. The median diagnostic values for M-NBI and C-WLI were as follows: accuracy, 90.4% and 64.8%; sensitivity, 60.0% and 40.0%; and specificity, 94.3% and 67.9%, respectively. The accuracy and specificity of M-NBI were greater than those of C-WLI (P < .001); the difference in sensitivity was not significant (P = .34). The combination of M-NBI with C-WLI significantly enhanced performance compared with C-WLI alone; accuracy increased from (median) 64.8% to 96.6% (P < .001), sensitivity increased from 40.0% to 95.0% (P < .001), and specificity increased from 67.9% to 96.8% (P < .001). CONCLUSIONS M-NBI, in conjunction with C-WLI, identifies small, depressed gastric mucosal cancers with 96.6% accuracy, 95.0% sensitivity, and 96.8% specificity. These values are better than for C-WLI or M-NBI alone.

White opaque substance within superficial elevated gastric neoplasia as visualized by magnification endoscopy with narrow-band imaging: a new optical sign for differentiating between adenoma and carcinoma

BACKGROUND The microvascular pattern (MVP) as visualized by magnification endoscopy (ME) is a reliable marker for differentiating between benign and malignant gastric flat lesions. However, in cases of gastric neoplasia of 0-IIa type, it is sometimes impossible to visualize the MVP because a white opaque substance (WOS) obscures the subepithelial MVP. OBJECTIVE To investigate whether the morphology of the WOS could be a useful optical sign for discriminating between adenoma and carcinoma. SETTING Single tertiary referral center. MATERIALS Forty-six gastric neoplasias of only 0-IIa type (18 adenomas and 28 early carcinomas) were evaluated. INTERVENTION The prevalence and the morphology of the WOS as visualized by ME with narrow-band imaging (NBI) according to histologic type (adenoma vs carcinoma). MAIN OUTCOME MEASUREMENTS The WOS is more frequently present in adenomas than in carcinomas. With regard to the morphology of the WOS, 100% of the examples of WOS within adenomas demonstrated a regular distribution; in contrast, 83% of the examples of WOS within carcinomas showed an irregular distribution. RESULTS In cases in which a neoplasia of 0-IIa type showed either WOS with a regular distribution or a regular MVP, the sensitivity and specificity for discriminating adenoma from carcinoma were 94% and 96%, respectively. LIMITATIONS The number of cases was limited. The WOS has not yet been characterized by chemical analysis. CONCLUSION In cases in which the WOS is observed, rather than assessing the MVP, morphologic analysis of the WOS could be an alternative new optical sign for discriminating adenoma from carcinoma when using ME with NBI.

Novel endoscopic observation in Barrett’s oesophagus using high resolution magnification endoscopy and narrow band imaging

Background High resolution magnification endoscopy with narrow band imaging (NBI) may improve the detection of specialised intestinal metaplasia (SIM) and dysplasia in Barrett’s oesophagus.

Usefulness of magnifying endoscopy with narrow-band imaging for determining the horizontal extent of early gastric cancer when there is an unclear margin by chromoendoscopy (with video)

BACKGROUND Magnifying endoscopy (ME) with narrow-band imaging (NBI) may allow reliable delineation of the horizontal extent of early gastric cancers before endoscopic submucosal dissection (ESD). However, the advantages of ME with NBI over standard endoscopy with dye spraying (chromoendoscopy [CE]) have yet to be elucidated. OBJECTIVE To investigate the usefulness and limitations of ME with NBI when CE is unsuccessful for determining the horizontal extent of early gastric cancer. DESIGN Case series. SETTING Single tertiary referral center. MATERIALS Series of 350 consecutive early gastric cancers resected en bloc using ESD. INTERVENTION ME with NBI for cancers with unclear margins by CE. MAIN OUTCOME MEASUREMENTS The rate of successful delineation by ME with NBI for cancers that had demonstrated unclear margins using CE. RESULTS The proportion of cancers showing unclear margins using CE was 18.9% (66/350). Of these, 62 of 66 cancers were examined using ME with NBI, with the entire margins successfully delineated in 72.6% (45/62) of the lesions that had shown unclear margins using CE. The success rate was 0% for undifferentiated cancers, significantly lower than that for differentiated lesions (P < .00001). LIMITATIONS Even by using ME with NBI, endoscopic delineation remains difficult for undifferentiated lesions. CONCLUSIONS ME with NBI is an excellent modality for identifying the entire margin of early gastric cancers, when the margins are unclear using CE.

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society (JGES), in collaboration with the Japanese Gastric Cancer Association (JGCA), has produced ‘Guidelines for ESD and EMR for Early Gastric Cancer’, as a set of basic guidelines in accordance with the principles of evidence‐based medicine. These Guidelines cover the present state of knowledge and are divided into the following seven categories: Indications, Preoperative diagnosis, Techniques, Evaluation of curability, Complications, Long‐term postoperative surveillance, and Histology. Twenty‐three statements were finally accepted as guidelines, and the majority of these were obtained from descriptive studies with lower evidence levels. A number of statements had to be created by consensus (the lowest evidence level), as evidence levels remain low for many specific areas in this field.

Adverse reactions to azathioprine cannot be predicted by thiopurine S-methyltransferase genotype in Japanese patients with inflammatory bowel disease

Background and Aims:  Azathioprine (AZA) is associated with a high frequency of adverse reactions. We examined polymorphism of the thiopurine S‐methyltransferase (TPMT) gene to determine whether the TPMT genotype would be a predictive marker for the development of adverse reactions to AZA.

ENDOSCOPIC BALLOON DILATATION USING DOUBLE‐BALLOON ENDOSCOPY IS A USEFUL AND SAFE TREATMENT FOR SMALL INTESTINAL STRICTURES IN CROHN'S DISEASE

Background:  Endoscopic balloon dilatation (EBD) is a therapeutic option for intestinal strictures of Crohns disease (CD). Double‐balloon endoscopy (DBE) enables EBD to be performed even for deep‐situated strictures of the small intestine. The aim of this study was to clarify the efficacy and safety of EBD using DBE for small bowel strictures in patients with CD.

Novel Zoom Endoscopy Technique for Visualizing the Microvascular Architecture in Gastric Mucosa

We have developed and established a zoom endoscopy technique based on visualization of the mucosal microvascular architecture in units as small as the capillary in the normal stomach and early gastric cancer. With regard to the microvascular architecture of the normal stomach, the findings differed according to the section of the stomach. The gastric body showed a honeycomb-like subepithelial capillary network pattern with collecting venule, whereas the gastric antrum showed a coil-shaped subepithelial capillary network pattern. Regarding early gastric cancer, the following findings seemed to be specific for differentiated carcinoma: (1) a demarcation line between the cancerous and the noncancerous mucosa, (2) the disappearance of the regular subepithelial capillary network pattern, and (3) the presence of an irregular microvascular pattern. These findings, which were visualized by magnified observation, could be useful in clinical practice when we attempt to make a correct endoscopic diagnosis of flat reddened lesions (gastritis vs cancer) and when we attempt to determine the precise horizontal margin of early gastric cancer. This could help us to perform successful endoscopic resection based on endoscopic findings alone. In conclusion, our zoom endoscopy for visualizing the microvascular architecture in gastric mucosa could be a new system for diagnosing early gastric cancer.

Colonoscopy in the diagnosis of intestinal tuberculosis in asymptomatic patients

BACKGROUND Colonoscopy with terminal ileoscopy is crucial for the diagnosis of intestinal tuberculosis. This report describes characteristic endoscopic findings in patients with intestinal tuberculosis with few or no clinical symptoms. METHODS Data for 11 consecutive patients in whom a diagnosis of intestinal tuberculosis was made during the last 15 years in one facility were reviewed. Clinical findings and the frequency of endoscopic findings were evaluated. Mucosal lesions were classified into 4 types: type 1, circumferential ulceration with nodules; type 2, round or irregularly shaped small ulcers, arranged circumferentially, without nodules; type 3, multiple erosions restricted to the large intestine; and type 4, small ulcers or erosions restricted to the ileum. The gross endoscopic appearance of healed lesions included patulous ileocecal valve, pseudodiverticular deformity, and atrophic mucosal areas with aggregated ulcer scars. RESULTS Only one patient had remarkable clinical symptoms (anorexia and weight loss), whereas, the other 10 had few or no symptoms. The frequency of type 1, 2, 3, and 4 endoscopic findings was, respectively, 36%, 36%, 9%, and 18%. The frequencies for patulous ileocecal valve, pseudodiverticular deformity, and atrophic mucosal area were, respectively, 45%, 45%, and 91%. CONCLUSIONS When colonoscopy is performed in asymptomatic patients, it is important to be aware of subtle endoscopic findings that are characteristic for intestinal tuberculosis. Recognition of such findings may lead to a correct diagnosis of early stage intestinal tuberculosis.