Background and Study Aims: Colonoscopy is still considered the standard investigation for the detection of colorectal adenomas, but the miss rate, especially for small and flat lesions, remains unacceptably high. Chro...Background and Study Aims: Colonoscopy is still considered the standard investigation for the detection of colorectal adenomas, but the miss rate, especially for small and flat lesions, remains unacceptably high. Chromoscopy has been shown to increase the yield for lesion detection in inflammatory bowel disease. The aim of this randomized prospective study was to determine whether a combination of chromoscopy and structure enhancement could increase the adenoma detection rate in high-risk patients. Patients and Methods: All patients included in the trial had a personal history of colorectal adenomas and/or a family history of colorectal cancer (but excluding genetic syndromes). They were randomized to one of two tandem colonoscopy groups, with the first pass consisting of conventional colonoscopy for both groups, followed by either chromoscopy and structure enhancement (the “study" group) or a second conventional colonoscopy (the control group) for the second-pass colonoscopy. All detected lesions was examined histopathologically after endoscopic resection or biopsy. The principal outcome parameter was the adenoma detection rate; the number, histopathology, and location of lesions was also recorded. Results: A total of 292 patients were included in the study (146 patients in each group). The patients’demographic characteristics, the indications for colonoscopy, and the quality of bowel preparation were similar in the two groups. There was a significant difference between the two groups with respect to the median duration of the examination (18.9 minutes in the control group vs. 27.1 minutes for the study group, P < 0.001). Although more hyperplastic lesions were detected throughout the colon in the study group (P = 0.033), there was no difference between the two groups in either the proportion of patients with at least one adenoma or in the total number of adenomas detected. Chromoscopy and structure enhancement diagnosed significantly more diminutive adenomas (< 5mm) in the right colon, compared with controls (P = 0.039). Conclusions: On the basis of our results we cannot generally recommend the systematic use of chromoscopy and structure enhancement in a high-risk patient population, although the detection of small adenomas in the proximal colon was improved.展开更多
Background and Study Aim: Patients with long-standing in-flammatory bowel disease (IBD) have an increased risk of developing colonic dysplasias. Dysplastic changes in flat mucosa are likely to be missed by conventiona...Background and Study Aim: Patients with long-standing in-flammatory bowel disease (IBD) have an increased risk of developing colonic dysplasias. Dysplastic changes in flat mucosa are likely to be missed by conventional colonoscopy. Endoscopic fluorescence imaging, using 5-aminolevulinic acid (5-ALA) as photosensitizer, has evolved as a new technique to differentiate between normal colonic mucosa and dysplasia. We combined this technique with random biopsies to prospectively evaluate the occurrence of dysplasias in patients with long-standing IBD. Patients and Methods: 52 colonoscopies were performed in 42 consecutive patients (n = 28 with ulcerative colitis, n = 11 with Crohn’s colitis, n = 3 with indeterminate colitis; mean age 43 years, range 21-78) with long-standing IBD colitis (median disease duration 14 years, range 3-40). All patients were in clinical remission. Patients were examined using both conventional white light and by fluorescence colonoscopy using oral 5-ALA. Four biopsies were taken every 10cm frommucosa of normal appearance. In addition, macroscopically suspicious and fluorescence-positive areas were biopsied. Results: A total of 688 biopsies of red-fluorescent (n = 20) and nonfluorescent (n = 662) areas of mucosa were taken. Dysplasia was detected histopathologically in only two of the biopsies. These biopsies were taken from two polypoid lesions which were fluorescence-negative. Conclusions: The rate of colonic dysplasia in patients with long-standing IBD colitis may be lower than previously reported.展开更多
Background and study aims: The aim of the present study was to analyze the reasons for false findings on computed tomographic (CT) colonography. Patients and methods: A total of 100 consecutive CT colonography examina...Background and study aims: The aim of the present study was to analyze the reasons for false findings on computed tomographic (CT) colonography. Patients and methods: A total of 100 consecutive CT colonography examinations were carried out before conventional colonoscopies scheduled on the same day. Before the study, an experienced radiologist received training in analyzing CT colonographies. The radiologists and endoscopists were blinded to each others findings. The patients received standard polyethylene glycol bowel preparation and were scanned in the prone and supine positions using a helical CT scanner and commercially available software for image analysis. Each pair of examinations was later followed by an unblinded analysis, comparing the CT colonographies with video recordings of the conventional colonographies in order to determine the reasons for tumors being missed or false- positive diagnoses arising on CT colonography. Results: Ninety polyps were detected in 41 patients. For patients with tumors ≥ 5 mm and ≥ 10mm, the sensitivity was 67% and 75% , respectively, and the specificity was 84% and 95% , respectively. The most important reasons for the 38 false findings of tumors ≥ 5 mm were perception errors (21 of 38) and misinterpretation of flat lesions in particular, including a high- grade dysplasia and a flat elevated Dukes A carcinoma. Residual stool was frequently the reason for misinterpreting lesions ≥ 10 mm (four of 10). Conclusions: Perception errors were the main reason for false findings of lesions ≥ 5 mm, including one flat malignant lesion. Residual stool caused four of 10 false findings for lesions ≥ 10 mm. Reading CT colonographies requires a high level of expertise, and conventional colonography is still regarded as the gold standard for detecting colorectal lesions.展开更多
文摘Background and Study Aims: Colonoscopy is still considered the standard investigation for the detection of colorectal adenomas, but the miss rate, especially for small and flat lesions, remains unacceptably high. Chromoscopy has been shown to increase the yield for lesion detection in inflammatory bowel disease. The aim of this randomized prospective study was to determine whether a combination of chromoscopy and structure enhancement could increase the adenoma detection rate in high-risk patients. Patients and Methods: All patients included in the trial had a personal history of colorectal adenomas and/or a family history of colorectal cancer (but excluding genetic syndromes). They were randomized to one of two tandem colonoscopy groups, with the first pass consisting of conventional colonoscopy for both groups, followed by either chromoscopy and structure enhancement (the “study" group) or a second conventional colonoscopy (the control group) for the second-pass colonoscopy. All detected lesions was examined histopathologically after endoscopic resection or biopsy. The principal outcome parameter was the adenoma detection rate; the number, histopathology, and location of lesions was also recorded. Results: A total of 292 patients were included in the study (146 patients in each group). The patients’demographic characteristics, the indications for colonoscopy, and the quality of bowel preparation were similar in the two groups. There was a significant difference between the two groups with respect to the median duration of the examination (18.9 minutes in the control group vs. 27.1 minutes for the study group, P < 0.001). Although more hyperplastic lesions were detected throughout the colon in the study group (P = 0.033), there was no difference between the two groups in either the proportion of patients with at least one adenoma or in the total number of adenomas detected. Chromoscopy and structure enhancement diagnosed significantly more diminutive adenomas (< 5mm) in the right colon, compared with controls (P = 0.039). Conclusions: On the basis of our results we cannot generally recommend the systematic use of chromoscopy and structure enhancement in a high-risk patient population, although the detection of small adenomas in the proximal colon was improved.
文摘Background and Study Aim: Patients with long-standing in-flammatory bowel disease (IBD) have an increased risk of developing colonic dysplasias. Dysplastic changes in flat mucosa are likely to be missed by conventional colonoscopy. Endoscopic fluorescence imaging, using 5-aminolevulinic acid (5-ALA) as photosensitizer, has evolved as a new technique to differentiate between normal colonic mucosa and dysplasia. We combined this technique with random biopsies to prospectively evaluate the occurrence of dysplasias in patients with long-standing IBD. Patients and Methods: 52 colonoscopies were performed in 42 consecutive patients (n = 28 with ulcerative colitis, n = 11 with Crohn’s colitis, n = 3 with indeterminate colitis; mean age 43 years, range 21-78) with long-standing IBD colitis (median disease duration 14 years, range 3-40). All patients were in clinical remission. Patients were examined using both conventional white light and by fluorescence colonoscopy using oral 5-ALA. Four biopsies were taken every 10cm frommucosa of normal appearance. In addition, macroscopically suspicious and fluorescence-positive areas were biopsied. Results: A total of 688 biopsies of red-fluorescent (n = 20) and nonfluorescent (n = 662) areas of mucosa were taken. Dysplasia was detected histopathologically in only two of the biopsies. These biopsies were taken from two polypoid lesions which were fluorescence-negative. Conclusions: The rate of colonic dysplasia in patients with long-standing IBD colitis may be lower than previously reported.
文摘Background and study aims: The aim of the present study was to analyze the reasons for false findings on computed tomographic (CT) colonography. Patients and methods: A total of 100 consecutive CT colonography examinations were carried out before conventional colonoscopies scheduled on the same day. Before the study, an experienced radiologist received training in analyzing CT colonographies. The radiologists and endoscopists were blinded to each others findings. The patients received standard polyethylene glycol bowel preparation and were scanned in the prone and supine positions using a helical CT scanner and commercially available software for image analysis. Each pair of examinations was later followed by an unblinded analysis, comparing the CT colonographies with video recordings of the conventional colonographies in order to determine the reasons for tumors being missed or false- positive diagnoses arising on CT colonography. Results: Ninety polyps were detected in 41 patients. For patients with tumors ≥ 5 mm and ≥ 10mm, the sensitivity was 67% and 75% , respectively, and the specificity was 84% and 95% , respectively. The most important reasons for the 38 false findings of tumors ≥ 5 mm were perception errors (21 of 38) and misinterpretation of flat lesions in particular, including a high- grade dysplasia and a flat elevated Dukes A carcinoma. Residual stool was frequently the reason for misinterpreting lesions ≥ 10 mm (four of 10). Conclusions: Perception errors were the main reason for false findings of lesions ≥ 5 mm, including one flat malignant lesion. Residual stool caused four of 10 false findings for lesions ≥ 10 mm. Reading CT colonographies requires a high level of expertise, and conventional colonography is still regarded as the gold standard for detecting colorectal lesions.
