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Humphris J.,Gastroenterology and Liver Services
Tropical gastroenterology : official journal of the Digestive Diseases Foundation | Year: 2012

Confocal laser endomicroscopy (CLE) is an advanced imaging technique which combines conventional white light endoscopy (WLE) with an integrated or probe based confocal microscope. This allows microscopic examination of the surface epithelium and in vivo diagnosis during endoscopy. Established CLE applications include the diagnosis of Barrett's oesophagus, gastric intestinal metaplasia, coeliac disease and microscopic colitis. CLE can differentiate hyperplastic from adenomatous polyps in the colon and may obviate the need to biopsy all polyps at endoscopy. CLE is particularly helpful in surveillance endoscopy in inflammatory bowel disease where it has been shown to reduce the number of biopsies required and improve the detection of dysplasia. The future of CLE may be with new contrast agents to allow for molecular tagging and improved endoscopic diagnoses. The aim of this review is to describe the technology and techniques involved in CLE, and discuss the evolving applications in obtaining "virtual biopsy" throughout the GI tract.

Lunney P.C.,University of Sydney | Leong R.W.L.,Gastroenterology and Liver Services
Alimentary Pharmacology and Therapeutics | Year: 2012

Background: Smoking is the best-characterised environmental association of ulcerative colitis (UC). Smoking has been observed to exert protective effects on both the development and progression of UC. Aims: To examine the association between UC and smoking, possible pathogenic mechanisms and the potential of nicotine as a therapeutic agent in the treatment of UC. Methods: A literature search was conducted through MEDLINE, using the MeSH search terms 'ulcerative colitis' and 'smoking' or 'nicotine'. Relevant articles were identified through manual review. The reference lists of these articles were reviewed to include further appropriate articles. Results: Ulcerative colitis is less prevalent in smokers. Current smokers with a prior diagnosis of UC are more likely to exhibit milder disease than ex-smokers and nonsmokers. There is conflicting evidence for smokers having reduced rates of hospitalisation, colectomy and need for oral corticosteroids and immunosuppressants to manage their disease. Multiple potential active mediators in smoke may be responsible for these clinical effects, including nicotine and carbon monoxide, but the precise mechanism remains unknown. Nicotine has demonstrated variable efficacy in the induction of remission in UC when compared to placebo and conventional medicines. Despite this, the high frequency of adverse events limits its clinical significance. Conclusions: Nicotine's application as a therapeutic treatment in ulcerative colitis is limited. Presently, it may be an option considered only in selected cases of acute ulcerative colitis refractory to conventional treatment options. This review also questions whether nicotine is the active component of smoking that modifies risk and inflammation in ulcerative colitis. © 2012 Blackwell Publishing Ltd.

Lunney P.C.,University of Sydney | Kariyawasam V.C.,Gastroenterology and Liver Services | Wang R.R.,University of Sydney | Middleton K.L.,University of Sydney | And 5 more authors.
Alimentary Pharmacology and Therapeutics | Year: 2015

Background Smoking demonstrates divergent effects in Crohn's disease (CD) and ulcerative colitis (UC). Smoking frequency is greater in CD and deleterious to its disease course. Conversely, UC is primarily a disease of nonsmokers and ex-smokers, with reports of disease amelioration in active smoking. Aim To determine the prevalence of smoking and its effects on disease progression and surgery in a well-characterised cohort of inflammatory bowel diseases (IBD) patients. Methods Patients with smoking data of the Sydney IBD Cohort were included. Demographic, phenotypic, medical, surgical and hospitalisation data were analysed and reported on the basis of patient smoking status. Results 1203 IBD patients were identified comprising 626 CD and 557 UC with 6725 and 6672 patient-years of follow-up, respectively. CD patients were more likely to smoke than UC patients (19.2% vs. 10.2%, P < 0.001). A history of smoking in CD was associated with an increased proportional surgery rate (45.8% vs. 37.8%, P = 0.045), requirement for IBD-related hospitalisation (P = 0.009) and incidence of peripheral arthritis (29.8% vs. 22.0%, P = 0.027). Current smokers with UC demonstrated reduced corticosteroid utilisation (24.1% vs. 37.5%, P = 0.045), yet no reduction in the rates of colectomy (3.4% vs. 6.6%, P = 0.34) or hospital admission (P = 0.25) relative to nonsmokers. Ex-smokers with UC required proportionately greater immunosuppressive (36.2% vs. 26.3%, P = 0.041) and corticosteroid (43.7% vs. 34.5%, P = 0.078) therapies compared with current and never smokers. Conclusions This study confirms the detrimental effects of smoking in CD, yet failed to demonstrate substantial benefit from smoking in UC. These data should encourage all patients with IBD to quit smoking. © 2015 John Wiley & Sons Ltd.

Selinger C.P.,Gastroenterology and Liver Services | Leong R.W.,Gastroenterology and Liver Services
Inflammatory Bowel Diseases | Year: 2012

Ulcerative colitis (UC) and Crohn's disease (CD) may directly result in morbidity and rarely mortality from complications such as colorectal cancer or sepsis. Mortality rates compared with the matched general population, measured by standardized mortality ratio, may therefore be increased. This review examines the evidence derived from cohort- and population-based mortality studies. In CD the majority of studies and two meta-analyses demonstrated increased standardized mortality ratios of ≈1.5-fold, especially for those diagnosed at younger ages and requiring extensive or multiple resection surgery. In UC mortality rates are similar to those of the general population in most studies and a meta-analysis. Proctocolectomy removes the inflammatory burden of UC and can manage colorectal dysplasia but may result in perioperative complications. There is no clear temporal trend of improvement in survival for either CD or UC. Few data are available from countries outside Europe and North America, so geographical influences remain largely unknown. Copyright © 2012 Crohn's & Colitis Foundation of America, Inc.

Wang R.,Gastroenterology and Liver Services | Leong R.W.,Gastroenterology and Liver Services
World Journal of Gastroenterology | Year: 2014

To examine and evaluate recent evidence regarding the epidemiology, pathogenesis and management of colorectal cancer (CRC) development in inflammatory bowel disease (IBD)-primary sclerosing cholangitis (PSC) patients. Using the PubMed database, a literature search was conducted for relevant articles in English from the past 10 years. Relevant studies investigating PSC as a risk factor for CRC in IBD in the context of incidence and prevalence, pathogenesis, prevention and prognosis were included in this review. Recent evidence increasingly points to PSC as a significant risk factor in the development of CRC in patients with concomitant IBD. PSC may be an important risk factor for CRC in different populations worldwide. The mechanism for this increase in risk is still unclear. The efficacy of UDCA as a chemopreventive agent remains controversial. Liver transplantation does not halt the development of CRC, although there is not enough evidence to suggest that it is associated with increased incidence of CRC. While routine colonoscopic surveillance should be performed in patients with concurrent PSC and IBD, more high-level evidence is required to support the benefits of the procedure. While many new developments have taken place in the last decade, the pathogenesis and optimal management of CRC development in IBD-PSC patients remain unclear. © 2014 Baishideng Publishing Group Inc. All rights reserved.

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