Yoshiki Nomura

The diagnostic accuracy of high-resolution endoscopy, autofluorescence imaging and narrow-band imaging for differentially diagnosing colon adenoma.

BACKGROUND AND STUDY AIMS Conventional colonoscopy can result in unnecessary biopsy or endoscopic resection due to its inability to distinguish adenomas from hyperplastic polyps. This study therefore evaluated the efficacy of high-resolution endoscopy (HRE), autofluorescence imaging (AFI), and narrow-band imaging (NBI) in discriminating colon adenoma from hyperplastic polyps. PATIENTS AND METHODS This was a prospective multicenter study in patients undergoing AFI and NBI examinations. HRE, AFI, and NBI images were classified into two groups based on morphological characteristics, the predominant color intensities, and the visibility of meshed capillary vessels, respectively. Each of the endoscopic photographs were independently evaluated by a single endoscopist. The images were then assessed by three specialists and three residents, the latter having performed < 500 colonoscopies and < 30 NBI and AFI examinations. Diagnostic test statistics were calculated to compare the accuracy in differentiating colon adenoma from hyperplastic polyps for each method. RESULTS A total of 183 patients were enrolled in the study and 339 adenomas and 85 hyperplastic polyps were identified. AFI and NBI could distinguish adenoma from hyperplastic polyps with an accuracy of 84.9 % and 88.4 %, respectively, whereas HRE exhibited an accuracy of 75.9 %. In the 358 lesions in which the AFI diagnosis was consistent with that of NBI, the accuracy, sensitivity, and specificity were high, at 91.9 %, 92.7 %, and 92.9 %, respectively. During the study comparing specialists and residents, AFI and NBI dramatically improved the diagnostic accuracy of residents from 69.1 % to 86.1 % and 84.7 %, respectively. CONCLUSIONS Both AFI and NBI are considered to be feasible tools that can discriminate colon adenoma from hyperplastic polyps, and their use may be particularly beneficial for less-experienced endoscopists.

Back-to-Back Comparison of Auto-Fluorescence Imaging (AFI) Versus High Resolution White Light Colonoscopy for Adenoma Detection

BackgroundSome patients under close colonoscopic surveillance still develop colorectal cancer, thus suggesting the overlook of colorectal adenoma by endoscopists. AFI detects colorectal adenoma as a clear magenta, therefore the efficacy of AFI is expected to improve the detection ability of colorectal adenoma. The aim of this study is to determine the efficacy of AFI in detecting colorectal adenoma.MethodsThis study enrolled 88 patients who underwent colonoscopy at Asahikawa Medical University and Kushiro Medical Association Hospital. A randomly selected colonoscopist first observed the sigmoid colon and rectum with conventional high resolution endosopy (HRE). Then the colonoscopist changed the mode to AFI and handed to the scope to another colonoscopist who knew no information about the HRE. Then the second colonoscopist observed the sigmoid colon and rectum. Each colonoscopist separately recorded the findings. The detection rate, miss rate and procedural time were assessed in prospective manner.ResultsThe detection rate of flat and depressed adenoma, but not elevated adenoma, by AFI is significantly higher than that by HRE. In less-experienced endoscopists, AFI dramatically increased the detection rate (30.3%) and reduced miss rate (0%) of colorectal adenoma in comparison to those of HRE (7.7%, 50.0%), but not for experienced endoscopists. The procedural time of HRE was significantly shorter than that of AFI.ConclusionsAFI increased the detection rate and reduced the miss rate of flat and depressed adenomas. These advantages of AFI were limited to less-experienced endoscopists because experienced endoscopists exhibited a substantially high detection rate for colorectal adenoma with HRE.

Autofluorescence imaging and the quantitative intensity of fluorescence for evaluating the dysplastic grade of colonic neoplasms

Background and aimsAutofluorescence imaging (AFI) is a novel technology which can capture fluorescence emitted from intestinal tissues. While AFI is useful for detecting colorectal neoplasms, it is unclear whether AFI can facilitate the diagnosis by differentiating the extent of dysplasia of colorectal neoplasms. This study investigated the efficacy of AFI in discriminating high-grade from low-grade adenoma.Materials and methodsSixty-seven patients who underwent colonoscopy with AFI were enrolled in this study. The AFI images obtained from 158 lesions in these patients were visually classified into four categories, namely, green (G), green with magenta spots (GM), magenta with green spots (MG), and magenta (M), according to their color intensities, immediately after the examination. The AFI images of the lesions were quantified using an image-analytical software program (F index). Either the F index or the visual assessment was prospectively compared with the dysplastic grade.ResultsThe F index of the high-grade adenomas was significantly lower than that of the low-grade adenomas, hyperplasia, and normal mucosa (p < 0.05). The incidence of the lesions classified into the M classification for high-grade adenomas (55.6%) was significantly higher than that of either low-grade adenomas (20.8%) or hyperplasia (0%). No correlation was observed between the F index or the visual classification and the tumor shape. The F index was not influenced by the size of the lesion, while the size was significantly associated with the visual classification of AFI.ConclusionsAFI, particularly the F index, is considered to be a useful procedure for estimating the dysplastic grade of colonic adenomas.

Biomarkers predicting development of metachronous gastric cancer after endoscopic resection: an analysis of molecular pathology of Helicobacter pylori eradication

Metachronous gastric cancer (MGC) after endoscopic resection (ER) of gastric cancer still occurs to some degree even after Helicobacter pylori (H. pylori) treatment. We evaluated whether two biomarkers related to carcinogenesis expressed in intestinal metaplasia (IM) become predictors for MGC development after eradication. We performed a hospital‐based, case–control study of 75 patients, including 50 mucosal cancer patients who had undergone ER (Group DYS), and 25 age‐ and sex‐matched chronic gastritis patients for whom H. pylori had been successfully eradicated (control). Additionally, Group DYS patients were divided into two groups: 25 successfully H. pylori‐eradicated (eradicated group) and 25 un‐eradicated patients (persistent group). All patients were followed for 1 year. We analyzed microsatellite instability (MSI) and immunoperoxidase assays using a monoclonal antibody for the colonic phenotype (Das‐1). Both MSI and Das‐1 reactivity in IM were significantly higher in Group DYS than in the control (p < 0.05 and p < 0.01, respectively). MSI and Das‐1 reactivity were strong and independent predictors for gastric cancer (OR = 7.09, 95% CI 1.27–39.6, p = 0.03 for MSI and OR = 4.96, 95% CI 1.64–15.0, p = 0.005 for Das‐1 reactivity). The incidence of MSI tended to decrease in the eradicated group (p = 0.07), but not in the persistent group. The Das‐1 immunoreactivity in IM also declined in both the eradicated group and the control. Interestingly, all MGCs after ER were positive for MSI or Das‐1 reactivity. MSI or Das‐1 reactivity in IM strongly predicts the development of MGC. Patients in whom these biomarkers persist after eradication may therefore have a high risk of developing MGC.

Reduction of E-cadherin by human defensin-5 in esophageal squamous cells.

Barretts esophagus (BE) is metaplastic columnar epithelium converted from normal squamous epithelia in the distal esophagus that is thought to be a precancerous lesion of esophageal adenocarcinoma. BE is attributed to gastroesophageal reflux disease (GERD), and therefore gastric acid or bile acids are thought to be factors that cause epithelial cell damage and inflammation in the gastro-esophageal junction. The decrease of adherent junction molecules, E-cadherin has been reported to be associated with the progression of the Barretts carcinoma, but the initiation of BE is not sufficiently understood. BE is characterized by the presence of goblet cells and occasionally Paneth cells are observed at the base of the crypts. The Paneth cells possess dense granules, in which human antimicrobial peptide human defensin-5 (HD-5) are stored and secreted out of the cells. This study determined the roles of HD-5 produced from metaplastic Paneth cells against adjacent to squamous cells in the gastro-esophageal junction. A human squamous cell line Het-1A, was incubated with the synthetic HD-5 peptide as a model of squamous cell in the gastro-esophageal junctions, and alterations of E-cadherin were investigated. Immunocytochemistry, flowcytometry, and Western blotting showed that the expression of E-cadherin protein was decreased. And a partial recovery from the decrease was observed by treatment with a CD10/neprilysin inhibitor (thiorphan). In conclusion, E-cadherin expression in squamous cells was reduced by HD-5 using in vitro experiments. In gastro-esophageal junction, HD-5 produced from metaplastic Paneth cells may therefore accelerate the initiation of BE.

Capsule endoscopy is a feasible procedure for identifying a Diphyllobothrium nihonkaiense infection and determining the indications for vermifuge treatment.

Diphyllobothrium is a member of Cestoda family, which is the largest parasite of humans. The diagnosis of diphyllobothriasis is based on the detection of eggs in the stool. Because the remainder of the scolex causes a relapse in diphyllobothriasis, the scolex must be completely discharged to cure the parasite infection. However, the scolex or forefront of the Diphyllobothrium is difficult to detect with gastroduodenoscopy and colonoscopy, because most Diphyllobothrium attach to the jejunal wall. In the present case, capsule endoscopy detected proglottids as well as forefront of the parasite at jejunum. Based on the results of capsule endoscopy, the patient underwent additional vermifuge (anthelminthic) treatment to cure the diphyllobothriasis and discharged a worm measuring 3 m in length with a scolex. Capsule endoscopy is a practical option to determine whether additional vermifuge treatment is required through the detection of the proglottids as well as a scolex or forefront of the parasite.

The incidence and risk factors of venous thromboembolism in Japanese inpatients with inflammatory bowel disease: a retrospective cohort study

Background/Aims Venous thromboembolism (VTE) is a major extraintestinal manifestation in inflammatory bowel disease (IBD), regarded as an independent risk factor for VTE according to reports from Western countries. However, the incidence and risk factors of VTE in Asian IBD patients are not fully understood. We aimed to reveal the incidence and risk factors of VTE in Japanese IBD inpatients. Methods The incidence of VTE in inpatients with IBD (n=340), gastrointestinal cancers (n=557), and other gastrointestinal diseases (n=569) treated at our hospital from 2009 to 2013 was retrospectively investigated. The characteristics and laboratory data of IBD inpatients with and without VTE were compared in univariate and multivariate analyses. Clinical courses of VTE in IBD were surveyed. Results VTE was detected in 7.1% of IBD inpatients, significantly higher than in gastrointestinal cancer inpatients (2.5%) and inpatients with other gastrointestinal diseases (0.88%). The incidence of VTE in ulcerative colitis (UC) patients (16.7%) was much higher than that in those with Crohns disease (3.6%). In the univariate analysis, the risk factors were an older age, central venous catheter, prednisolone, surgery, low serum albumin, high serum C-reactive protein and D-dimer. According to a multivariate analysis, >50 years of age and surgery were the only risk factors. The in-hospital mortality rate of IBD inpatients with VTE was 4.2%. Conclusions The incidence of VTE with IBD, especially UC, was found to be high compared with other digestive disease, which was almost equivalent to that of Western countries. The efficacy of prophylaxis needs to be investigated in Asian IBD patients.

The Detection of Pancreatic and Retroperitoneal Plasmacytoma Helped to Diagnose Multiple Myeloma: A Case Report.

AbstractMultiple myeloma is characterized by the neoplastic proliferation of a single clone of plasma cells producing a monoclonal protein. However, the involvement of pancreas is a rare event. We herein report a rare case of pancreatic plasmacytoma, which was detected before the diagnosis of multiple myeloma.An 83-year-old male was referred to our hospital for further evaluation of obstructive jaundice and a pancreatic mass. A contrast-enhanced computed tomography (CT) scan revealed solid masses with homogenous enhancement in the pancreatic head and retroperitoneum. The histological findings of the retroperitoneal mass obtained by CT-guided biopsy showed multiple sheets of atypical plasma cells, which were positively immunostained for CD79a, CD138, and the &kgr; light chain. Serum immunoelectrophoresis detected M-component of immunoglobulin A-&kgr;, and the histological findings of the bone marrow revealed an abnormally increased number of atypical plasma cells with irregular nuclei and cytoplasmic vacuolation. The patient was therefore diagnosed to have multiple myeloma involving the pancreas and retroperitoneum. Although chemotherapy was performed, the patient died 6 months after the diagnosis.The pancreatic plasmacytoma was detected before the multiple myeloma in the present case. It is difficult to diagnose a pancreatic plasmacytoma without a history of multiple myeloma and related disease.

Pilot study of endoscopic retrograde 3-dimensional – computed tomography enteroclysis for the assessment of Crohn’s disease

Purpose Endoscopic retrograde ileography (ERIG) is developed in our institute and applied clinically for the diagnosis and assessment of the Crohn’s disease activity. We have further improved the technique using 3-dimensional – computed tomography enteroclysis (3D-CTE) and conducted a retrospective study to determine the feasibility and the diagnostic value of endoscopic retrograde 3D-CTE (ER 3D-CTE) in Crohn’s disease patients in a state of remission. Methods Thirteen Crohn’s patients were included in this pilot study. CTE was performed after the infusion of air or CO2 through the balloon tube following conventional colonoscopy. The primary endpoint of this study was to assess the safety of this method. Secondarily, the specific findings of Crohn’s disease and length of the visualized small intestine were assessed. Results The procedures were completed without any adverse events. Gas passed through the small intestine and enterographic images were obtained in 10 out of 13 cases, but, in the remaining patients, insertion of the balloon tubes into the terminal ileum failed. Various features specific to Crohn’s disease were visualized using ER 3D-CTE. A cobble stone appearance or hammock-like malformation was specific and effective for diagnosing Crohn’s disease and the features of anastomosis after the surgical operations were also well described. Therefore, this technique may be useful after surgery. Conclusion In this study, ER 3D-CTE was performed safely in Crohn’s disease patients and may be used for the diagnosis and follow-up of this disease.

The endoscopic findings of the upper gastrointestinal tract in patients with Crohn’s disease

Crohn’s disease (CD) is a type of chronic inflammatory bowel disease (IBD) associated with ulceration, and the main foci of the inflammation in CD patients are typically the terminal ileum and colon. However, in the upper gastrointestinal tract (GIT), including the esophagus, stomach and duodenum, inflammatory lesions are also detected as well, with a relatively high frequency (30–75%). Recent advances in imaging modalities, including endoscopy, have aided in the diagnosis of CD. Various lesions, including aphtha, erosion, ulcers, bamboo-joint-like appearance and notch-like appearance, are detected in the upper GI of CD patients. Of these lesions, the bamboo-joint-like appearance in the gastric cardiac region and notch-like appearance in the second portion of the duodenum are highly specific for CD, regardless of the disease activity at other sites. These two findings, particularly a bamboo-joint-like appearance, have therefore been considered as potential biomarkers for CD. Although proton pump inhibitors (PPIs) are administered as an initial treatment for upper GIT lesions of CD, the efficacy of this treatment remains controversial. The administration of mesalazine, steroids, immunosuppressant and biologic agents is expected to be effective for treating such lesions.