Time filter

Source Type

Sano, Japan

Hewett D.G.,Indiana University | Hewett D.G.,University of Queensland | Kaltenbach T.,Veterans Affairs Palo Alto Health Care System | Kaltenbach T.,Stanford University | And 6 more authors.
Gastroenterology | Year: 2012

BACKGROUND & AIMS: Almost all colorectal polyps ≤5 mm are benign, yet current practice requires costly pathologic analysis. We aimed to develop and evaluate the validity of a simple narrow-band imaging (NBI)-based classification system for differentiating hyperplastic from adenomatous polyps. METHODS: The study was conducted in 4 phases: (1) evaluation of accuracy and reliability of histologic prediction by NBI-experienced colonoscopists; (2) development of a classification based on color, vessels, and surface pattern criteria, using a modified Delphi method; (3) validation of the component criteria by people not experienced in endoscopy or NBI analysis (25 medical students, 19 gastroenterology fellows) using 118 high-definition colorectal polyp images of known histology; and (4) validation of the classification system by NBI-trained gastroenterology fellows, using still images. We performed a pilot evaluation during real-time colonoscopy. RESULTS: We developed a classification system for the endoscopic diagnosis of colorectal polyp histology and established its predictive validity. When all 3 criteria were used, the specificity ranged from 94.9% to 100% and the combined sensitivity ranged from 8.5% to 61.0%. The specificities of the individual criteria were lower although the sensitivities were higher. During realtime colonoscopy, endoscopists made diagnoses with high confidence for 75% of consecutive small colorectal polyps, with 89% accuracy, 98% sensitivity, and 95% negative predictive values. CONCLUSIONS: We developed and established the validity of an NBI classification system that can be used to diagnose colorectal polyps. In preliminary real-time evaluation, the system allowed endoscopic diagnoses of colorectal polyp histology. © 2012 AGA Institute. Source

Hayashi N.,Hiroshima University | Tanaka S.,Hiroshima University | Hewett D.G.,University of Queensland | Kaltenbach T.R.,Veterans Affairs Palo Alto Health Care System | And 4 more authors.
Gastrointestinal Endoscopy | Year: 2013

Background: A simple endoscopic classification to accurately predict deep submucosal invasive (SM-d) carcinoma would be clinically useful. Objective: To develop and assess the validity of the NBI international colorectal endoscopic (NICE) classification for the characterization of SM-d carcinoma. Design: The study was conducted in 4 phases: (1) evaluation of endoscopic differentiation by NBI-experienced colonoscopists; (2) extension of the NICE classification to incorporate SM-d (type 3) by using a modified Delphi method; (3) prospective validation of the individual criteria by inexperienced participants, by using high-definition still images without magnification of known histology; and (4) prospective validation of the individual criteria and overall classification by inexperienced participants after training. Setting: Japanese academic unit. Main Outcome Measurements: Performance characteristics of the NICE criteria (phase 3) and overall classification (phase 4) for SM-d carcinoma; sensitivity, specificity, predictive values, and accuracy. Results: We expanded the NICE classification for the endoscopic diagnosis of SM-d carcinoma (type 3) and established the predictive validity of its individual components. The negative predictive values of the individual criteria for diagnosis of SM-d carcinoma were 76.2% (color), 88.5% (vessels), and 79.1% (surface pattern). When any 1 of the 3 SM-d criteria was present, the sensitivity was 94.9%, and the negative predictive value was 95.9%. The overall sensitivity and negative predictive value of a global, high-confidence prediction of SM-d carcinoma was 92%. Interobserver agreement for an overall SM-d carcinoma prediction was substantial (kappa 0.70). Limitations: Single Japanese center, use of still images without prospective clinical evaluation. Conclusion: The NICE classification is a valid tool for predicting SM-d carcinomas in colorectal tumors. Copyright © 2013 by the American Society for Gastrointestinal Endoscopy. Source

Sato N.,Asahikawa University | Saijo Y.,Asahikawa University | Sasagawa Y.,Rumoi Municipal Hospital | Morimoto H.,Fukagawa Municipal Hospital | And 9 more authors.
Clinical and Experimental Hypertension | Year: 2015

Background: Combination antihypertensive therapy with an angiotensin receptor blocker (ARB) and a calcium channel blocker (CCB) or diuretics is common. This subanalysis investigated blood pressure (BP) variability in patients receiving ARB-based combination therapy. Methods: In a prospective, randomized, open-label trial, hypertensive outpatients (-65 years) who did not achieve their target BP with ARB monotherapy switched to losartan 50 mg/hydrochlorothiazide 12.5mg (ARB + D) or ARB plus amlodipine 5mg (ARB + C) for 12 months. Clinic BP and heart rate (HR), measured every 3 months, visit-to-visit variability and seasonal variation were evaluated. Results: No significant between-group differences in average, maximum, or minimum systolic or diastolic BP, or HR, were found. Visit-to-visit BP variability (systolic) was significantly higher in the ARB +D group than in the ARB + C group. When each group was subdivided into two seasonal groups (summer and winter), no significant between-group differences in BP were found. Multivariate regression analyses showed a tendency toward negative correlation between outdoor temperature and urinary albumin:creatinine ratio and estimated glomerular filtration rate at 12 months in the ARB + D group. Conclusion: Combination therapy with an ARB plus a CCB may be preferable to that with an ARB plus diuretics for decreasing BP variability. As for seasonal variability, both treatments can be used safely regardless of season. © 2014 Informa Healthcare USA. Source

Oba S.,Hiroshima University | Tanaka S.,Hiroshima University | Sano Y.,Sano Hospital | Oka S.,Hiroshima University | Chayama K.,Hiroshima University
Digestion | Year: 2011

The narrow-band imaging system can be used to examine the microvascular architecture and surface pattern on the mucosal surface with high sensitivity. The clinical significance of NBI observation is summarized as follows: (1) differential diagnosis of hyperplasia, adenoma, and carcinoma; (2) diagnosis according to the presence of a surface pattern as an alternative to magnifying endoscopic observation with dye spraying, and (3) determination of the invasion depth of an early colorectal carcinoma. However, at present, many NBI magnifying observation classifications for colorectal tumor exist in Japan. To internationally standardize the NBI observation criteria, a simple classification system is required. On the basis of these backgrounds, an international cooperative group (Colon Tumor NBI Interest Group - CTNIG) has developed a simple category classification (NICE classification: NBI International Colorectal Endoscopic Classification) which classifies NBI findings into types 1-3. Copyright © 2011 S. Karger AG, Basel. Source

Takizawa K.,Shizuoka Cancer Center | Ono H.,Shizuoka Cancer Center | Kakushima N.,Shizuoka Cancer Center | Tanaka M.,Shizuoka Cancer Center | And 7 more authors.
Gastric Cancer | Year: 2013

Background: The behavior of early gastric cancer (EGC) with mixed-type histology (differentiated and undifferentiated) is incompletely understood. This study aimed to clarify the clinicopathological features of EGC with mixed-type histology in relation to lymph node (LN) metastasis. Methods: Clinicopathological data from 410 patients who underwent surgical resection for intramucosal EGC were reviewed. Lesions were classified into four types according to the proportion of differentiated and undifferentiated components at histopathology: pure differentiated (PD) type, mixed predominantly differentiated (MD) type, mixed predominantly undifferentiated (MU) type, and pure undifferentiated (PU) type. We examined the clinicopathological differences between PD and MD, and between PU and MU, and the rate of LN metastasis according to tumor size and ulceration. Results: Moderately differentiated adenocarcinoma was the primary component in MD relative to PD (90.7 vs. 46.1 %). Signet ring cell carcinoma was the main component in PU relative to MU (81.5 vs. 33.3 %). LN metastasis was more common in MU than PU (19.0 vs. 6.0 %). For intramucosal tumors larger than 20 mm without lymphovascular invasion and without ulceration, the rate of LN metastasis was 0 % for MD and 24 % for MU. For intramucosal lesions less than 30 mm with ulceration but without lymphovascular invasion, the rate of LN metastasis was 0 % for MD and 20 % for MU. Conclusions: Histologically mixed-type EGC with a predominantly undifferentiated component should be managed as an undifferentiated-type tumor. Further investigation is required to determine whether mixed-type EGC with a predominantly differentiated component could be managed the same way as a differentiated-type EGC. © 2012 The International Gastric Cancer Association and The Japanese Gastric Cancer Association. Source

Discover hidden collaborations