Prospective and randomized study to evaluate the clinical impact of cap assisted colonoscopy (CAC).

BACKGROUND: Although colonoscopy is the standard procedure in the diagnosis of colorectal neoplasia, a significant number of clinical relevant lesions may be missed even by experienced endoscopists using current technology. A transparent cap mounted at the tip of a colonoscope may be an easy way to extend the visual field during colonoscopy and may improve the detection rate of mucosal lesions. MATERIAL AND METHODS: The significance of cap assisted (CAC) vs. conventional colonoscopy (CC) on polyp detection rate was evaluated in a prospective randomized controlled trial in 504 patients. RESULTS: CC and CAC detected polyps in 39.3 % and 31.8, not significantly different. There was also no significant difference between CAC and CC according to age, sex, indication for colonoscopy, diverticulosis, sedation, bowel cleansing, withdrawal time, time/number of attempts to intubate the cecal walve, number, localization, size or histology of polyps,. However, the time to reach the cecal floor and the overall time of colonoscopy were significantly lower for CAC (1 minute). CONCLUSION: CAC was without clinical impact on polyp detection rate or performance of colonoscopy.

Cap-assisted colonoscopy (CAC) significantly extends visualization in the right colon.

BACKGROUND: Although colonoscopy is the standard procedure in the diagnosis of colorectal neoplasia, a significant number of clinically relevant lesions may be missed even by experienced endoscopists using current technology. Particular problems may occur with blind spots behind the semilunar folds and within the right colon. A transparent cap mounted at the tip of a colonoscope may be an easy way to extend the visual field during colonoscopy and may improve the detection rate of mucosal lesions. However, data in the literature are controversial and the quantity of the potential extension of visualization by a transparent cap has not been reported yet. MATERIAL AND METHODS: The significance of cap-assisted colonoscopy (CAC) to increase visualization within different colonic segments (rectum, sigmoid colon, descending colon, transverse colon, ascending colon, cecum) was quantitatively analyzed by randomized back-to-back colonoscopies with and without cap. The investigations were performed in a colonic training model by 5 investigators. The inner colonic surface was stained by a raster of dots and the number of dots counted during colonoscopy served as a measure for the visible surface area of each segment. RESULTS: The time to advance the colonoscope to the respective colonic segments and the overall time to reach the cecum were not significantly different between conventional and CAC. In contrast, overall withdrawal time and withdrawal times for the cecum, ascending colon, descending colon and rectum were significantly longer for CAC, but not for the transverse and sigmoid colon. Visualization of the colonic surface was significantly increased during CAC. Overall, 59.76 ± 2.70 % of the maximal countable dots were visualized without cap and 85.36 ± 9.62 % with cap. The improvement of visualization was only significant for the right colon, but not for the rectum, sigmoid or descending colon. CONCLUSION: The finding of the present study suggests that the extension of visualization by CAC may be of particular value for the right colon.

Fructose malabsorption: how much fructose can a healthy subject tolerate?

BACKGROUND/AIMS: In a prospective study, we evaluated fructose absorption capacity in 17 healthy female volunteers aged 16-27 years. METHODS: All volunteers underwent analysis of their daily food intake diary and standardized breath tests. The volunteers were challenged consecutively with oral intake of 50, 25 and 15 g of fructose. RESULTS: The average daily ingestion of fructose (19.54 ± 14.95 g) was not different between volunteers with positive and negative breath tests. On day 1, 53% of subjects exhibited a significant (≥20 ppm) increase in breath hydrogen and gastrointestinal symptoms upon challenge with 50 g of fructose. Moreover, 37.5% of the volunteers with a negative breath test became positive upon a second challenge with 50 g of fructose but remained asymptomatic. On day 2, 1 of the 9 volunteers (12.5%) with a positive breath test on day 1 exhibited an asymptomatic positive breath test upon exposure to 25 and 15 g of fructose on day 3. The 8 volunteers with a negative test (25 g of fructose) remained negative after a second exposure to 25 g of fructose. CONCLUSION: The results of this study indicate that hydrogen breath tests with fructose challenge of 50 g of fructose are inappropriate to characterize clinically significant fructose malabsorption.

Evidence for mast cell activation in patients with therapy-resistant irritable bowel syndrome.

Previous findings suggested an involvement of mast cells in the pathogenesis of irritable bowel syndrome (IBS). The pathophysiological significance of mast cells is defined both by their number in tissue and by their activity. In the present pilot study activity of mast cells in patients with therapy-resistant IBS was investigated for the first time systematically. Twenty patients with therapy-resistant IBS were investigated for the presence of a pathologically increased mast cell mediator release by means of a validated structured interview suitable to identify mast cell mediator-related symptoms and by determing selected surrogate parameters for mast cell activity. Nineteen of the 20 patients presented mast cell mediator-related symptoms. Pathologically increased mast cell activity-related coagulation and fibrinolysis parameters were detected in 11 of 12 patients investigated in that regard. One patient had an elevated level of methylhistamine in urine. The present data provide evidence that in patients with therapy-resistant IBS a pathologically increased systemic mast cell activity may occur with high prevalence. This finding fits to the idea of an assumed contribution of activated mast cells in the pathophysiology of IBS.

Krefeld CONTRA study: conventional peroral Esophago-Gastro-Duodenoscopy (EGD) vs. transnasal EGD--a prospective and randomised study with independent evaluation of conscious sedation, endoscope diameter, and access path.

BACKGROUND: The guidelines of the German Gastroenterology Society (Deutsche Gesellschaft für Verdauungs- und Stoffwechselkrankheiten, DGVS) demand the presence of an additional qualified person solely responsible for patient monitoring during sedated endoscopy. Transnasal esophagogastroduodenoscopy (EGD) allows easy access to the upper gastrointestinal tract and may avoid the complications induced by conscious sedation and reduce medical costs. PATIENT AND METHOD: 120 patients referred to diagnostic EGD were assigned to six groups: group 1, unsedated peroral EGD with normal-caliber endoscope; group 2, unsedated peroral EGD with small-caliber endoscope; group 3, sedated peroral EGD with normal-caliber endoscope; group 4, sedated peroral EGD with small-caliber endoscope; group 5, unsedated transnasal EGD with small-caliber endoscope; group 6, sedated transnasal EGD with small-caliber endoscope. Outcome parameters included objective (duration, oxygen saturation) and subjective measures (standardised visual analogue scales) of the endoscopy staff (handling, insertion, retroflexion, tolerability, overall assessment) and patients (pain, unpleasantness, sore throat, choking, gagging, meteorism, anxiety, acceptability). RESULTS: The patients were comparable according to age, sex, anxiety, and respiratory function before EGD. Sedoanalgesia was without effect on EGD handling and duration, patient tolerability and overall assessment by endoscopists and assistants. Negative effects of sedoanalgesia (decreased oxygen saturation, patient acceptability) were much lower and without significance for transnasal compared to peroral EGD. Patient tolerability and acceptability of the endoscopic staff (handling, insertion, retroflexion) were significantly better for the small-caliber endoscope. Duration of unsedated transnasal EGD was slightly but significantly longer, pain, unpleasantness, and anxiety slightly but significantly higher compared to sedated peroral EGD. However, these differences could no loner be detected seven days after endoscopy. Cost analysis revealed major advantage for transnasal EGD. CONCLUSION: Unsedated transnasal EGD may replace diagnostic peroral EGD, reduces costs with acceptable patient discomfort and has advantagous acceptability of the endoscopic staff.

Prospective comparison between double-balloon enteroscopy and spiral enteroscopy.

BACKGROUND AND STUDY AIMS: Push enteroscopy, balloon-guided, and single- and double-balloon enteroscopy (DBE) are now well established techniques in gastrointestinal endoscopy for small-bowel imaging and therapy. There are no published prospective studies comparing DBE with spiral enteroscopy and so the aim of the current study was to compare the performance of the two techniques in patients undergoing diagnostic enteroscopy. PATIENTS AND METHODS: Between January and December 2009, 35 patients referred for diagnostic enteroscopy were prospectively assigned to either spiral enteroscopy (n=18) or DBE (n=17). The performance of the two techniques was compared. RESULTS: The patients were comparable with regard to age, sex, and indication for enteroscopy. Investigation performance, as assessed by time of insertion into the pylorus, the depth of insertion, the duration of the enteroscopy, and the amount of sedoanalgesia required were not significantly different between spiral enteroscopy and DBE. In 40% of the investigations, enteroscopy could detect abnormalities in the intestinal mucosa, in particular inflammatory changes and ulcers and, to a lesser extent, angiodysplasia. No significant difference in pathological findings could be detected between the two groups; however, clinically, diagnostic yield appeared to be higher for DBE (47.1% vs. 33.4%; n.s.). CONCLUSION: Although this small study appears to show that DBE has a clinically higher diagnostic yield than spiral enteroscopy, larger studies are needed to confirm this preliminary finding.