Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Colonoscopes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,297 records · Page 72Linked to original sources
PubMed1984

Direct vision brush cytology with colonoscopy: an aid to the accurate diagnosis of colonic strictures.

The accuracy of direct vision brush cytology at colonoscopy was compared with colonoscopic biopsies, colonoscopy alone and radiology in the diagnosis of colonic strictures. There were 82 brushings in 79 patients; 55 had malignant and 24 had benign lesions. Cytology was correct in 66 (81 per cent), and biopsy was less accurate with 53 (68 per cent) correct reports. The combined accuracy of cytology and biopsy was 88 per cent. Whilst an endoscopic diagnosis was usually correct (96 per cent), direct vision brush cytology had an important place in the accurate tissue diagnosis of colonic strictures, particularly those in the rectosigmoid.

Barium Sulfate↗
PubMed1987

Symptomatic submucosal lipoma of the large bowel.

Symptomatic large bowel lipomata may be of considerable size and usually present in middle age with symptoms of obstruction or bleeding. Although they are rare, their recognition is important so that patients may be spared unnecessary colonic resection for a presumptive malignant diagnosis. Colonoscopic removal may often be feasible. Six cases are reported together with a review of the literature emphasizing the characteristic features.

Adult↗
PubMed1988

Angiodysplasia of the colon: endoscopic diagnosis and treatment.

Of 34 patients with massive lower intestinal bleeding, 17 (11 men and 6 women, age range 33-85 years; mean 64.8 years) were diagnosed as having angiodysplasia of the colon. The diagnosis was made by colonoscopy and the lesions were treated successfully by fulguration in 13 (86.6 per cent) of 15 patients. Two of the 17 patients underwent surgical resection of the involved intestinal segment. One patient still has sporadic intestinal haemorrhage, and another patient died from bleeding of the left colon after blind right colectomy. The remaining 13 patients have had no further bleeding in the 1-7 years following colonoscopic fulguration. Colonoscopy is a useful method of diagnosing angiodysplasia of the colon and affords the possibility of treatment.

Adolescent↗
PubMed1990

Photodynamic therapy for colorectal cancer: a quantitative pilot study.

Ten patients with colorectal cancers unsuitable for operation were treated with endoscopic photodynamic therapy (PDT). The patients were assessed before treatment, and at 1 week and 1 month after treatment by colonoscopy with biopsy and endoluminal ultrasound examination. The depth of tumour was measured and the effect of PDT was quantified by measuring the reduction in tumour depth. All patients were sensitized with 2.5 mg kg-1 of haematoporphyrin derivative, 48 h before phototherapy. A standard treatment protocol of light exposure was used. Up to four parts of the tumour were treated with 50J of red light (630 nm) from a tuneable dye laser, through a flexible optical fibre passed through the colonoscope and inserted into the tumour. Two patients with small lesions are tumour-free 20 and 28 months after PDT. One treatment of an advanced tumour was complicated by a haemodynamically significant secondary haemorrhage. PDT may be most suitable for the treatment of small tumours or for small areas of persistent tumour where the bulk has been removed by alternative techniques.

Adenocarcinoma↗
PubMed1992

Function of the human colon.

Despite the volume of research on human colonic dysfunction, little is known about colonic function in health. This has stemmed partly from the difficulty in obtaining access to the organ. Two approaches have been used: studies on patients with stomas, and intestinal intubation techniques. The colonoscope has also recently been used to gain access. All these methods have limitations and results must be interpreted with caution. The accepted roles of the colon include the conservation of water and electrolytes and the controlled evacuation of faeces. Recent research has demonstrated its importance as a metabolic organ with an influence on overall metabolism, an effect that may in large part be attributed to the activity of colonic microflora. Evidence demonstrating that the defunctioned colon behaves differently from the functioning colon in the same individual has implications for a proper understanding of the organ, as practically all previous in vivo studies have been conducted in cleansed or defunctioned human colon.

Colon↗
PubMed1993

New technique to measure mucosal metabolism and its use to map substrate utilization in the healthy human large bowel.

A new method of assessing substrate utilization in gastrointestinal mucosal specimens is described. Small human endoscopic biopsy specimens with wet weights ranging between 1.4 and 12.2 mg were used to quantify the oxidation of three metabolic substrates, glucose, glutamine and butyrate, through to carbon dioxide over a 2-h period. The technique proved to be reproducible and capable of distinguishing variations in mucosal metabolism between individuals (P < 0.0001 for each substrate). Results were similar to those obtained previously using human and rat colonocytes. To characterize the metabolism of the healthy large bowel, specimens were obtained from five regions in 15 patients who had a normal colonoscopic examination. The results show that butyrate is the preferred fuel source of large bowel mucosa, followed by glutamine, then glucose (P < 0.01). There was no significant regional variation in utilization of the three substrates between the five regions; with respect to glutamine, this is contrary to previous findings.

Adult↗
PubMed2005

Cancer surveillance in ulcerative colitis.

BACKGROUND: Patients with ulcerative colitis are at a higher risk of developing colorectal cancer than those without the disease. Surveillance programmes are used routinely to detect dysplasia and cancer in patients with ulcerative colitis. However, such programmes are poorly effective. This article discusses possible improvements suggested by recent research. METHODS: Papers relating to cancer associated with ulcerative colitis and surveillance programmes to detect such cancer were identified using Medline searches. Further papers were identified from the reference lists of identified papers. RESULTS: The probability of cancer for all patients with ulcerative colitis regardless of disease extent was 2 per cent at 10 years, 8 per cent at 20 years and 18 per cent at 30 years; the overall prevalence of colorectal cancer in any patient was 3.7 per cent. Indications for colonoscopic surveillance are extensive disease for 8-10 years, especially in those with active inflammation, a family history of colorectal cancer and primary sclerosing cholangitis. Problems affecting surveillance include the diagnosis of dysplasia, difficulty in differentiating 'sporadic' adenomas from a dysplasia-associated lesion or mass, and decision making based on surveillance findings. Molecular genetic and endoscopic advances to alleviate these problems are discussed. CONCLUSION: Rates of detection of dysplasia can be improved by chromoendoscopy. Molecular genetics has the potential to identify patients most at risk of cancer and can differentiate between different types of lesion.

Aneuploidy↗
PubMed2005

Screening and preventive behaviors one year after predictive genetic testing for hereditary nonpolyposis colorectal carcinoma.

BACKGROUND: Prevention benefits from predictive genetic testing for cancer will only be fully realized if appropriate screening is adopted after testing. The current study assessed screening and preventive behaviors during 12 months after predictive genetic testing for hereditary nonpolyposis colorectal carcinoma (HNPCC) in an Australian clinical cohort. METHODS: Participants received predictive genetic testing for HNPCC at one of five Australian familial cancer clinics. Data on self-reported screening behaviors (colonoscopy, and endometrial sampling and transvaginal ultrasound for women) and prophylactic surgery (colectomy, and hysterectomy and bilateral oophorectomy for women) were collected using postal questionnaires before (baseline) and 12 months after receipt of genetic test results. Age, gender, perceived risk of cancer, and cancer-specific distress were assessed as predictors of colonoscopic screening. RESULTS: In the current study, 114 participants returned baseline questionnaires (32 carriers and 82 noncarriers of an HNPCC mutation). Ninety-eight participants also returned a 12-month follow-up questionnaire. Of those > or = 25 years, 73% reported having had a colonoscopy before genetic testing. At follow-up, 71% (15 of 25) of carriers and 12% (8 of 65) of noncarriers reported having a colonoscopy in the 12 months after receipt of test results. The reduction in colonoscopy among noncarriers was statistically significant (P < 0.001). High perceived risk was associated with colonoscopy at baseline. At follow-up, mutation status was the only variable significantly associated with colonoscopy. Among female mutation carriers, 47% reported having transvaginal ultrasonography and 53% endometrial sampling during follow-up. There was low uptake of prophylactic surgery for colorectal, endometrial, or ovarian carcinomas. CONCLUSIONS: The majority of individuals reported appropriate screening behaviors after predictive genetic testing for HNPCC. The small group of noncarriers who had screening after genetic testing might benefit from additional counseling.

Adult↗
PubMed1984

Some studies of the bacterial flora associated with the mucosa of the human gastrointestinal tract.

Specimens of mucosal tissue of the small and large bowel obtained either by a colonoscope or during surgical operations were investigated quantitatively for their bacterial flora. A detailed prescription of the methodology using an anaerobic chamber is given. Most of the mucosal specimens of the small intestine as well as all the specimens of the large intestine contained bacteria (about 10(4) germs/g). Predominantly, Bacteroides, gram-positive rods, and cocci were isolated. In contrast to the gut lumen flora anaerobic bacteria of the mucosal flora did not outnumber the aerobes. In patients with inflammatory bowel disease or with carcinoma of the colon the mucosal flora showed no demonstrable alterations even after undergoing a sulphonamide therapy.

Bacteria, Aerobic↗
PubMed1992

Cost savings in mass population screening for colorectal cancer resulting from the early detection and excision of adenomas.

The widely-accepted hypothesis of a development sequence from colorectal adenoma to carcinoma is felt by clinicians to legitimate adenoma excision during routine colonoscopic investigation. Using published data on adenoma development, and adenoma prevalence data derived from the Nottingham colorectal cancer screening trial, the number of carcinomas prevented by early excision as a result of screening is predicted. The cost-effectiveness of early excision is then evaluated with reference to the expected treatment costs saved. These cost savings are found to represent a discount on the overall costs of mass population screening for colorectal cancer.

Adenoma↗
PubMed1995

Primary sclerosing cholangitis and ulcerative colitis: evidence for increased neoplastic potential.

Primary sclerosing cholangitis (PSC) is a biliary destructive disease mostly affecting patients with ulcerative colitis (UC). PSC has been suggested to be an independent risk factor for the development of colorectal malignancy in UC. Patients with PSC also have an increased risk of developing cholangiocarcinoma. This study aimed at assessing the cumulative risk of colorectal neoplasia in PSC and UC, and also to determine risk factors for the development of cholangiocarcinoma. Fifty-eight PSC patients were included. Forty PSC patients having extensive UC were each matched to two control patients of the same age, with extensive colitis and a comparable duration of the colitis, but without PSC. All UC patients had been under colonoscopic surveillance with multiple biopsies. Among the 40 PSC patients with UC, 16 developed colonic dysplasia or carcinoma, versus 10 in the control group (P < .001). The absolute cumulative risk of developing colorectal dysplasia/carcinoma in the PSC/UC groups was 9%, 31%, and 50% after 10, 20, and 25 years of disease duration. In the group with UC only, the corresponding risk was 2%, 5%, and 10%, respectively (P < .001). Ten patients with PSC developed cholangiocarcinoma, all but one having UC. In the control group, no cholangiocarcinoma occurred. Patients with PSC and UC with colorectal neoplasia developed cholangiocarcinoma significantly more often compared with patients with UC and PSC without colonic dysplasia/carcinoma (P < .02). This study demonstrates not only that patients with PSC and UC have a significantly higher risk of developing colorectal neoplasia compared with patients having UC only, but also that patients with PSC and UC having colorectal neoplasia are more prone to develop cholangiocarcinoma.

Adolescent↗
PubMed2007

Azathioprine and mesalazine-induced effects on the mucosal flora in patients with IBD colitis.

BACKGROUND: The impact of azathioprine and 5-aminosalicylic acid (5-ASA) on the innate immunity and mucosal flora is unknown. The study investigated the influence of IBD treatment on the concentrations and spatial organization of mucosal bacteria using fluorescence in situ hybridization with 16s r-RNA targeting probes. METHODS: We prospectively investigated colonoscopic biopsies from five groups of 20 subjects each: patients with ulcerative or indeterminate colitis treated with azathioprine (group 1), azathioprine and 5-ASA (group 2), 5-ASA (group 3), untreated IBD (group 4), and healthy controls. RESULTS: The elevated numbers of leukocytes in mucus of IBD patients were reduced nearly to norm in patients treated with azathioprine alone. In contrast, 5-ASA therapy had no influence on mucus leukocyte migration and was associated with the lowest concentrations of mucosal bacteria of all IBD groups. The suppressed migration of leukocytes in azathioprine-treated patients was accompanied by a 28-fold higher concentration of mucosal bacteria when compared with the 5-ASA group or a 1000-fold increase when compared with healthy controls. The percent of the epithelial surface covered with adherent bacteria (P < 0.001) and the amenability of mucosal bacteria (P = 0.01) were also significantly increased in the azathioprine-treated group compared with all other IBD groups. The patients receiving both 5-ASA and azathioprine did not differ statistically from untreated IBD patients either in mucus leukocyte migration or in bacterial concentrations. CONCLUSIONS: Azathioprine and 5-ASA induce opposite effects on the mucus barrier. Concomitant therapy of 5-ASA and azathioprine mutually neutralizes the effects of both on the mucosal flora and the barrier function.

Adult↗
PubMed2003

Predictors of metachronous colorectal neoplasms in sporadic adenoma patients.

Our objective was to assess the overall risk of subsequent colorectal neoplasms (cancer or adenoma) in relation with the various characteristics of the index lesion in a cohort of patients who underwent endoscopic polypectomies of colorectal adenomas. A total of 1086 patients with adenomas of the large bowel were reported between 1979 and 1999 at the National Cancer Institute of Milan during a screening program for colorectal carcinoma. Data on patients who had colonoscopic examinations and treatments were collected prospectively. The relation between colorectal cancer (CRC) and adenoma features was assessed by computing the hazard ratio (HR) values and corresponding confidence intervals (95% CI) according to Cox proportional hazard models. Of the 1086 eligible patients (487 females, 579 males), 736 had single adenomas (67.7%) and 350 had multiple adenomas (32.3%). Histologic examination revealed 772 cases of tubular adenoma (73%), 205 cases of tubulovillous adenoma and 80 cases of villous adenoma (7.5%). Severe dysplasia was found in 3.3% of the cases. During the 11393 person-years of follow-up, with an average time of surveillance of 10.5 years, colorectal carcinomas developed in 10 patients (0.8%) and a new adenoma in 323 patients (29%). Multivariate analysis showed that male gender (HR 1.6; 95% CI 1.3-2.0), multiple polyps (HR 1.6; 95% CI 1.3-2.0), polyps larger than 2 cm (HR 1.5; 95% CI 1.1-2.1), tubulovillous and villous histology (HR 1.3; 95% CI 1.0-1.6 and HR 1.8; 95% CI 1.2-2.6, respectively) at index polypectomy were statistically significant risk factors for developing metachronous adenomatous polyps. The standardized incidence rates (SIR) for CRC was 0.52 (95% CI 0.25-0.95). The SIR was increased in subjects with severe dysplasia (2.8; 95% CI 0.34-1.02). Some features of large bowel adenomas are strongly correlated with an increased risk of metachronous adenomas and colorectal cancer. However, the endoscopic polypectomy is able to reduce by 50% the incidence of CRC in patients with large bowel adenomas.

Adenoma↗
PubMed2004

Colorectal cancer risk in adenoma patients: a nation-wide study.

Colorectal cancer incidence after adenoma removal has been studied in selected populations of adenoma patients. Our study estimates the trend in colorectal cancer incidence after adenoma removal in actual clinical practice. From PALGA, a nationwide network and registry of histo- and cytopathology in the Netherlands, we extracted data of all patients diagnosed with colorectal adenomas between 1 January 1988 and 1 October 1998. The data were used to calculate population-based colorectal cancer incidence rates after adenoma removal. A total of 78,473 adenoma patients were followed for a mean of 4.5 years after the first adenoma removal. The colorectal cancer incidence ratio compared with the general population matched by age and gender was 38.4 (37.3-39.5) in the first year after adenoma removal and 1.5 (95% confidence interval (CI): 1.4-1.6) after Year 1. The incidence ratio decreased from 2.8 (2.5-3.1) in Year 2 to 0.9 (0.6-1.2) in Years 9-11. This time trend is the opposite of the upward time trend that was expected after adenoma removal. Adenoma patients in the Netherlands are at increased risk for colorectal cancer compared to the general population. The high cancer incidence in Years 1-5 after polypectomy can be explained by a colonoscopic sensitivity for cancer of approximately 90%.

Adenoma↗
PubMed2005

Helicobacter pylori infection is associated with colon adenomatous polyps detected by high-resolution colonoscopy.

Helicobacter pylori (H. pylori) is associated with the development of cancer in the stomach, but both positive and negative associations were reported with colorectal neoplasia. We sought to determine whether H. pylori is associated with colon neoplasia in Japanese population. We examined 332 patients who underwent routine high-resolution total colonoscopy and serologic testing for IgG antibodies agonist H. pylori. Subjects who received cyclooxygenase-2 inhibitors or previous eradication therapy and those with borderline titer levels were excluded from data analysis (n = 27). Seronegative control subjects were from the same study population to maximize the representativeness. There were no significant differences in age and gender between the 2 patient groups. A significant increase in the incidence of adenomatous polyps (p < 0.0001) and decrease in normal colonoscopic findings (p < 0.0005) were observed in seropositive patients than those seronegative. Our study indicates an etiological link of H. pylori infection to colorectal neoplasia and the need of routine colonoscopy in seropositive patients.

Adenomatous Polyps↗
PubMed2006

New immunochemical fecal occult blood test with two-consecutive stool sample testing is a cost-effective approach for colon cancer screening: results of a prospective multicenter study in Chinese patients.

The purpose of the study is to evaluate a new immunochemical fecal occult blood test method (Hemosure IFOBT), and compare it to the Guaiac-based chemical method (CFOBT) for colorectal cancer detection. A hypothetical sequential method (SFOBT), in which IFOBT was used only as a confirmatory test for CFOBT, was also evaluated. A total of 324 patients were recruited from 5 major hospitals in Beijing, China. For each patient, 3 consecutive stool samples were collected for simultaneous CFOBT and IFOBT tests, followed by colonoscopic examination. We compared the sensitivity and specificity of the 3 methods (CFOBT, IFOBT and SFOBT) in two settings, with the first 2 consecutive samples versus all 3 samples. Although the sensitivity for the detection of cancer and large (>20 mm) or multiple adenoma was similar for all 3 methods in the three-sample setting, in the two-sample setting IFOBT had higher sensitivity than SFOBT for detecting cancer (87.8% vs. 75.5%, respectively, p < 0.05) and large (>20 mm) or multiple adenomas (65.4% vs. 42.3%, respectively, p < 0.05). The IFOBT also had a higher specificity than the CFOBT (89.2% vs. 75.5%, respectively, p < 0.01) in "normal" individuals defined by colonoscopy in the three-sample setting. Comparing two-sample setting to the three-sample setting, both CFOBT and SFOBT showed significant loss of sensitivity for the detection of cancer as well as adenoma, whereas the sensitivity for IFOBT did not change significantly. Overall, IFOBT with two-sample testing showed compatible sensitivity and specificity to the three-sample testing, and had a lower relative cost per cancer detected than the three-sample testing. In conclusion, the new Hemosure IFOBT with two consecutive stool samples appears to be the most cost-effective approach for colon cancer screening.

Adenoma↗
PubMed1990

Natural history of colorectal polyps and the effect of polypectomy on occurrence of subsequent cancer.

To elucidate the natural history of colorectal polyps and to observe the influence of endoscopic polypectomy on the incidence of colorectal cancer, we conducted a retrospective cohort study of all patients who had undergone colonoscopic examination at the Center for Adult Diseases, Osaka, between April 1974 and December 1985. The study subjects consisted of a control group (760 non-polyp patients) and a polyp group (648 polyp patients, including 136 treated by polypectomy at the initial examination). These subjects were followed up until the end of 1987 by record linkage with the Osaka Cancer Registry's file to observe the occurrence of colorectal cancer. The O/E (observed/expected numbers derived from the general population) was 5.1 (95% confidence interval = 2.5-9.4) and 1.0 (0.1-3.6) for the polyp and control group, respectively. When subjects in the polyp group were categorized into polypectomy and non-polypectomy sub-groups, the O/E was 2.3 (0.1-12.6) and 8.0 (3.4-15.8) respectively. The relative risk of undergoing polypectomy to developing subsequent cancer was estimated at 0.3 (0.1-2.1). These results suggest an increased risk of developing cancer among polyp patients and the possibility of prophylactic effect of polypectomy against subsequent cancer. A large-scale and long-term follow-up study is required to confirm these findings.

Age Factors↗
PubMed2004

Risk factors for peritoneal dissemination of colorectal cancer.

BACKGROUND AND OBJECTIVES: The aim of this study was to clarify the risk factors associated with positive peritoneal dissemination (PPD) of colorectal cancer (CRC). METHODS: From June 2000 to September 2002, 143 CRC patients who underwent elective curative (79.0%) or non-curative (21.0%) open laparotomy were prospectively studied. Clinical evaluations including classical factors, colonoscopic evaluation, intraoperative evaluation, and pathological features were recorded. PPD was diagnosed when macro- (MAPD) or microscopic peritoneal dissemination (MIPD) was evident. Positive peritoneal cytology from initially existing ascites or washing lavage indicated MIPD. Various factors were analyzed with univariate (Chi-square test) and then multivariate analyses (logistic regression test) to search for the risk factors of PPD. RESULTS: Overall, MIPD, MAPD, and PPD were found in 2.8%, 6.3%, and 9.1%, respectively. Univariate analysis identified age (< or =59 years), CA19-9 (> or = 34.6 U/ml), poor differentiation, circumferential involvement (> or = 3 quadrants), ascites volume (>80 ml), pN+, and pT4 as risk factors of PPD. PPD did not occur in patients with well-differentiated tumors, less circumferential involvement (< 2 quadrants), or no lymph node metastasis. After multivariate analysis, CA19-9 (Odds ratio (95% CI), 8.6 (1.7-43.1)), pT4 (9.0 (1.3-61.0)), and age (5.26 (1.1-25.0)) remained significant risk factors. CONCLUSION: CA19-9 (> or = 34.6 U/ml), pT4, and age (< or =59 years) were significant risk factors of PPD.

Adult↗