ORCID Profile
0000-0002-4529-3543
Current Organisations
University of Queensland
,
Colonoscopy Clinic
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Publisher: Springer Science and Business Media LLC
Date: 04-12-2012
Publisher: BMJ
Date: 10-11-2020
DOI: 10.1136/GUTJNL-2020-321753
Abstract: Large (≥20 mm) sessile serrated lesions (L-SSL) are premalignant lesions that require endoscopic removal. Endoscopic mucosal resection (EMR) is the existing standard of care but carries some risk of adverse events including clinically significant post-EMR bleeding and deep mural injury (DMI). The respective risk-effectiveness ratio of piecemeal cold snare polypectomy (p-CSP) in L-SSL management is not fully known. Consecutive patients referred for L-SSL management were treated by p-CSP from April 2016 to January 2020 or by conventional EMR in the preceding period between July 2008 and March 2016 at four Australian tertiary centres. Surveillance colonoscopies were conducted at 6 months (SC1) and 18 months (SC2). Outcomes on technical success, adverse events and recurrence were documented prospectively and then compared retrospectively between the subsequent time periods. A total of 562 L-SSL in 474 patients were evaluated of which 156 L-SSL in 121 patients were treated by p-CSP and 406 L-SSL in 353 patients by EMR. Technical success was equal in both periods (100.0% (n=156) vs 99.0% (n=402)). No adverse events occurred in p-CSP, whereas delayed bleeding and DMI were encountered in 5.1% (n=18) and 3.4% (n=12) of L-SSL treated by EMR, respectively. Recurrence rates following p-CSP were similar to EMR at 4.3% (n=4) versus 4.6% (n=14) and 2.0% (n=1) versus 1.2% (n=3) for surveillance colonoscopy (SC)1 and SC2, respectively. In a historical comparison on the endoscopic management of L-SSL, p-CSP is technically equally efficacious to EMR but virtually eliminates the risk of delayed bleeding and perforation. p-CSP should therefore be considered as the new standard of care for L-SSL treatment.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2010
DOI: 10.1038/AJG.2010.245
Abstract: Colonoscopy provides imperfect protection against colorectal cancer and is operator dependent. Colonoscopies typically are poorly documented. We aimed to determine whether videorecording impacts short-term performance of colonoscopy. We videorecorded routine colonoscopies by seven colonoscopists, with and without their awareness. Colonoscopy quality was measured by blinded assessment of inspection time and technique. From pre- to post-awareness of videorecording, mean inspection time increased by 49% for all colonoscopies combined and increased significantly for four in idual colonoscopists. The overall quality of mucosal inspection technique improved by 31% after awareness of videorecording. Awareness of videorecording improved physician performance of colonoscopy. Further investigation of the role of videorecording in achieving sustained improvements in the quality performance of colonoscopy, including increases in adenoma detection, is warranted.
Publisher: American Medical Association (AMA)
Date: 13-02-2006
DOI: 10.1001/ARCHINTE.166.3.294
Abstract: Hemochromatosis in white subjects is mostly due to homozygosity for the common C282Y substitution in HFE. Although clinical symptoms are preventable by early detection of the genetic predisposition and prophylactic treatment, population screening is not currently advocated because of the discrepancy between the common mutation prevalence and apparently lower frequency of clinical disease. This study compared screening for hemochromatosis in subjects with or without a family history. We assessed disease expression by clinical evaluation and liver biopsy in 672 essentially asymptomatic C282Y homozygous subjects identified by either family screening or health checks. We also observed a subgroup of untreated homozygotes with normal serum ferritin levels for up to 24 years. Prevalence of hepatic iron overload and fibrosis were comparable between the 2 groups. Disease-related conditions were more common in male subjects identified by health checks, but they were older. Hepatic iron overload (grades 2-4) was present in 56% and 34.5% of male and female subjects, respectively hepatic fibrosis (stages 2-4) in 18.4% and 5.4% and cirrhosis in 5.6% and 1.9%. Hepatic fibrosis and cirrhosis correlated significantly with the hepatic iron concentration, and except in cases of cirrhosis, there was a 7.5-fold reduction in the mean fibrosis score after phlebotomy. All subjects with cirrhosis were asymptomatic. Screening for hemochromatosis in apparently healthy subjects homozygous for the C282Y mutation with or without a family history reveals comparable levels of hepatic iron overload and disease. Significant hepatic fibrosis is frequently found in asymptomatic subjects with hemochromatosis and, except when cirrhosis is present, is reversed by iron removal.
Publisher: Elsevier BV
Date: 04-2017
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2010
DOI: 10.1038/AJG.2009.757
Abstract: Hyperplastic polyposis syndrome (HPS) confers an increased risk of colorectal cancer and is difficult to manage clinically. Because both polyps and resultant cancers display the CpG island methylator phenotype and mutation of the BRAF oncogene, and because sporadic cancers with these characteristics are associated with cigarette smoking, we hypothesized that cigarette smoking may predispose to the development of HPS. This was a case-control study with two independent control series conducted at a tertiary hospital in Brisbane, Queensland, Australia. Cases comprised patients with HPS (n=32) recruited through the database of the Queensland Familial Bowel Registry, who satisfied the World Health Organization international classification for HPS. Cases were compared with colonoscopy controls (n=298) defined as consecutive patients undergoing colonoscopy for clinical indications, who were free from polyps. We also compared cases with a second set of population controls (n=645) selected at random from a population register serving the catchment area for cases. This was an observational study, and all participants completed a questionnaire to obtain a comprehensive smoking history. The prevalence rate of current smoking was 47% in HPS patients, 17% in colonoscopy controls, and 12% in population controls. HPS patients were significantly more likely to be current smokers than were either colonoscopy controls (odds ratio (OR)=8.3, 95% confidence interval (CI): 3.0-22.9) or population controls (OR=12.7, 95% CI: 4.9-33.1). Cigarette smoking is strongly associated with HPS, thus suggesting that smoking exposure may increase the expression of this condition. Further studies should examine the possible benefits of quitting smoking in HPS patients.
Publisher: Wiley
Date: 03-11-2014
DOI: 10.1111/DEN.14433
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2010
DOI: 10.1038/AJG.2010.247
Abstract: Problems with the quality of colonoscopy are well recognized. Variation in colonoscopist performance is compounded by payment structures that reward volume rather than quality. Payment reform has emerged as one strategy to address these and more systemic problems in the quality of health care. Various forms of value-based purchasing might encourage a realignment of incentives, and allow reimbursement to be directly linked with clinically important goals of colonoscopy. This paper proposes criteria for the selection of quality measures, and three candidate indicators to define quality for the purpose of payment reform in colonoscopy: cecal intubation rate, adenoma detection rate, and recommended post-polypectomy surveillance interval. These measures represent valid, credible, and reliable indicators of the quality of colonoscopy for colorectal cancer screening and surveillance. Payment reform should explicitly link public reporting and performance on these quality measures to payment for colonoscopy.
Publisher: Elsevier BV
Date: 08-2012
DOI: 10.1016/J.GIE.2012.04.454
Abstract: Polyps seen and not removed during colonoscope insertion are sometimes unable to be found during withdrawal. To investigate the impact of additional inspection during instrument insertion on adenoma detection in sedated patients undergoing routine screening or surveillance colonoscopy. Randomized, controlled trial. University hospital and associated ambulatory surgery center. Patients undergoing elective screening or surveillance colonoscopy. Patients were randomized to undergo colonoscopy with 3 minutes of dedicated inspection time during insertion plus 6 minutes during withdrawal versus 9 minutes of inspection on instrument withdrawal. The primary outcome measure was the adenoma detection rate (proportion of patients with adenomas) between patients in whom inspection for adenomas was performed partly on instrument insertion compared with patients for whom inspection was performed entirely on withdrawal. There was no difference in the proportion of patients with 1 or more adenomas between the inspection on insertion group (52%) and the inspection on withdrawal group (58%). There were no significant differences in total procedure time, time taken to remove polyps, sedation doses, or after-procedure pain between groups. Single-center study with two endoscopists. Inspection during colonoscope insertion offered no additional benefit compared with an equivalent period of inspection performed entirely during withdrawal. These results do not support an additional role for routine inspection during colonoscope insertion.
Publisher: Elsevier BV
Date: 07-2010
DOI: 10.1016/J.GIEC.2010.03.001
Abstract: Colonoscopy is a dominant modality for colorectal cancer prevention in average-risk patients aged 50 years and older. Non-polypoid colorectal neoplasms (NP-CRNs) are likely a significant contributing factor to interval colorectal cancers because they have a higher prevalence in Western populations than previously thought, are more difficult to detect visually with conventional colonoscopy, and are more likely to contain advanced histology than polypoid neoplasms, regardless of size. The accurate identification and complete removal of NP-CRNs is thus an integral part of high-quality colonoscopy, and a critical component of the ongoing efforts to make colorectal cancer screening programs widely available, effective, and accepted by patients. In this article, the authors examine the quality indicators for colonoscopy, present the reasons for interval cancers, and discuss the relation between NP-CRNs and quality colonoscopy.
Publisher: Oxford University Press (OUP)
Date: 06-2010
DOI: 10.1093/JNCI/DJQ189
Publisher: Elsevier BV
Date: 2015
Publisher: Elsevier BV
Date: 04-2004
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.GIE.2011.10.030
Abstract: No useful comparative data exist on the relative realism of commercially available devices for simulating colonoscopy. To develop an instrument for quantifying realism and provide the first wide-ranging empiric comparison. Repeated measures, observational study. Nineteen experienced colonoscopists completed cases on 4 colonoscopy simulators (AccuTouch, GI Mentor II, Koken, and Kyoto Kagaku) and evaluated each device. A medical simulation center in a large tertiary hospital. For each device, colonoscopists completed the newly developed Colonoscopy Simulator Realism Questionnaire (CSRQ), which contains 58 items grouped into 10 subscales measuring the realism of different aspects of the simulation. Subscale scores are weighted and combined into an aggregated score, and there is also a single overall realism item. Overall, current colonoscopy simulators were rated as only moderately realistic compared with real human colonoscopy (mean aggregated score, 56.28/100 range, 48.39-60.45, where 0 = "extremely unrealistic" and 100 = "extremely realistic"). On both overall realism measures, the GI Mentor II was rated significantly less realistic than the AccuTouch, Kyoto Kagaku, and Koken (P < .001). There were also significant differences between simulators on 9 subscales, and the pattern of results varied between subscales. The study was limited to commercially available simulators, excluding ex-vivo models. The CSRQ does not assess simulated therapeutic procedures. The CSRQ is a useful instrument for quantifying simulator realism. There is no clear "first choice" simulator among those assessed. Each has unique strengths and weaknesses, reflected in the differing results observed across 9 subscales. These findings may facilitate the targeted selection of simulators for various aspects of colonoscopy training.
Publisher: Georg Thieme Verlag KG
Date: 06-2006
Abstract: The role of acetic acid spray during magnification chromocolonoscopy has not previously been evaluated. We aimed to compare the accuracy of predicting polyp histology at magnification colonoscopy, using acetic acid and indigo carmine, either alone or in combination. A total of 46 consecutive patients with polyps detected during colonoscopy which measured 10 mm or less were alternately ided into two groups. In group A patients, 1.5 % acetic acid was applied to the mucosa first, followed by indigo carmine spray in group B patients, the order was reversed. The pit pattern was assessed after application, in real time. All the lesions were resected and examined histologically. Altogether, 37 adenomas and 36 hyperplastic polyps were evaluated. In group A, the diagnostic accuracy after spraying with acetic acid was 95 %, which increased to 98 % after application of indigo carmine. In group B, the accuracy after indigo carmine application was 83 %. After subsequent spraying with acetic acid, images were enhanced in 70 % of patients, with an increase in accuracy to 97 %. The mean time required to obtain an initial clear image with the first dye was 14 seconds for both groups. This is the first description of the use of acetic acid for pit pattern analysis of colonic polyps. Its ease of use, low cost, and safety, together with its excellent accuracy in the assessment of polyp pit patterns suggest that this method could easily be applied to routine magnification colonoscopy.
Publisher: Wiley
Date: 04-2014
DOI: 10.1111/DEN.12281
Abstract: During colonoscopy, small and diminutive colorectal polyps are commonly encountered. It is estimated that at least one adenomatous polyp is detected in almost half of all patients undergoing screening colonoscopy. In contrast, the 'predict, resect, and discard' strategy for diminutive and small colorectal polyps is a current topic especially in Western countries. 'Is this an acceptable policy in Japan?' Herein, we report the results of a questionnaire survey with regard to the management of diminutive colorectal polyps, including the thoughts of Japanese endoscopists regarding the 'predict, resect, and discard' strategy. At the moment, we propose that this strategy should be used by skilled endoscopists only.
Publisher: Elsevier BV
Date: 09-2012
DOI: 10.1053/J.GASTRO.2012.05.006
Abstract: 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. 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. 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 in idual criteria were lower although the sensitivities were higher. During real-time colonoscopy, endoscopists made diagnoses with high confidence for 75% of consecutive small colorectal polyps, with 89% accuracy, 98% sensitivity, and 95% negative predictive values. 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.
Publisher: Wiley
Date: 29-03-2019
DOI: 10.1111/DEN.13330
Publisher: Routledge
Publisher: Wiley
Date: 02-12-2016
DOI: 10.1111/DEN.12761
Abstract: Small-caliber endoscopes such as gastroscopes or pediatric colonoscopes are occasionally required to negotiate fixed or angulated colons. However, the use of a new ultrathin instrument (diameter 7.0 mm) narrower than other conventional colonoscopes has not been evaluated. The aim of the present study was to compare the use compare the use of an ultrathin colonoscope (UTC) with a pediatric colonoscope (PDC) for colonoscopy in older female patients. A prospective, randomized, controlled trial was conducted in a single academic endoscopy unit. A total of 77 female patients aged ≥70 years undergoing unsedated colonoscopy were randomized to colonoscopy with a UTC (n = 39) or PDC (n = 38). Primary outcome measurement was the degree of pain using a numerical rating scale, and secondary outcomes were cecal intubation rate, ileal intubation rate, time to cecum and adenoma detection rate. There was a significant difference in reported pain using the numerical rating scale (median, UTC 1 vs PDC 4, P < 0.0001). Cecal intubation rates were 97.4% in UTC and 92.1% in PDC (P = 0.36), and ileal intubation rates were 82.0% and 89.4% (P = 0.76), respectively. However, median times to cecum were significantly longer using UTC compared with PDC (15.2 min vs 11.1 min, P = 0.022). Adenoma detection rates were 30.7% in UTC and 26.3% in PDC (P = 0.80). Colonoscopy using UTC was almost equivalent to that of PDC in older female patients, with significantly less pain compared with PDC. UTC may be an alternative to PDC for the difficult colon.
Publisher: Elsevier BV
Date: 12-2009
DOI: 10.1016/J.SOCSCIMED.2009.09.048
Abstract: Hospitals involve a complex socio-technical health system, where communication failures influence the quality of patient care. Research indicates the importance of social identity and intergroup relationships articulated through power, control, status and competition. This study focused on interspecialty communication among doctors for patients requiring the involvement of multiple specialist departments. The paper reports on an interview study in Australia, framed by social identity and communication accommodation theories of doctors' experiences of managing such patients, to explore the impact of communication. Interviews were undertaken with 45 doctors working in a large metropolitan hospital, and were analysed using Leximancer (text mining software) and interpretation of major themes. Findings indicated that intergroup conflict is a central influence on communication. Contested responsibilities emerged from a model of care driven by single-specialty ownership of the patient, with doctors allowed to evade responsibility for patients over whom they had no sense of ownership. Counter-accommodative communication, particularly involving interpersonal control, appeared as important for reinforcing social identity and winning conflicts. Strategies to resolve intergroup conflict must address structural issues generating an intergroup climate and evoke interpersonal salience to moderate their effect.
Publisher: Elsevier BV
Date: 12-2010
DOI: 10.1016/J.SOCSCIMED.2010.08.013
Abstract: Emergency clinicians undertake boundary-work as they facilitate patient trajectories through the Emergency Department (ED). Emergency clinicians must manage the constantly-changing dynamics at the boundaries of the ED and other hospital departments and organizations whose services emergency clinicians seek to integrate. Integrating the care that differing clinical groups provide, the services EDs offer, and patients' needs across this journey is challenging. The journey is usually accounted for in a linear way - as a "continuity of care" problem. In this paper, we instead conceptualize integrated care in the ED using a complex adaptive systems (CAS) perspective. A CAS perspective accounts for the degree to which other departments and units outside of the ED are integrated, and appropriately described, using CAS concepts and language. One year of ethnographic research was conducted, combining observation and semi-structured interviews, in the EDs of two tertiary referral hospitals in Sydney, Australia. We found the CAS approach to be salient to analyzing integrated care in the ED because the processes of categorization, diagnosis and discharge are primarily about the linkages between services, and the communication and negotiation required to enact those linkages, however imperfectly they occur in practice. Emergency clinicians rapidly process large numbers of high-need patients, in a relatively efficient system of care inadequately explained by linear models. A CAS perspective exposes integrated care as management of the patient trajectory within porous, shifting and negotiable boundaries.
Publisher: Elsevier BV
Date: 06-2005
DOI: 10.1016/J.BEHA.2004.10.001
Abstract: Hereditary haemochromatosis is a primary inherited disorder of iron metabolism leading to progressive iron loading of parenchymal cells of the liver and other organs with erse clinical manifestations, including cirrhosis, diabetes and skin pigmentation. This chapter will focus on HFE-associated hereditary haemochromatosis, which accounts for approximately 90% of cases in Caucasian populations. Penetrance is incomplete, with variable clinical expression. The majority of cases demonstrate biochemical expression, but a much lower proportion develop advanced disease. Clinical disease--especially hepatic fibrosis--is related to the level of body iron stores, which is reflected primarily in the liver. The available evidence indicates that adequate screening and diagnostic strategies ensure that early case detection and treatment occur prior to the development of irreversible end-organ damage. The most cost-effective methods of early case detection are family (cascade) screening and evaluation of potential cases by primary care physicians with a high index of clinical suspicion.
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.GIE.2011.04.005
Abstract: Colonoscopy is less effective in the proximal compared with the distal colon. To describe the success rate, yield, and safety of retroflexion of the right side of the colon after a careful forward-viewing examination. Prospective observational study. Tertiary-care hospital outpatient endoscopy center and associated ambulatory surgery center. A total of 1000 consecutive adults undergoing elective screening or surveillance colonoscopy, without previous bowel resection, inflammatory bowel disease, or polyposis syndromes. After cecal intubation, a careful examination of the cecum to the hepatic flexure was performed in the forward view with removal of all identified polyps. The colonoscope was then reinserted to the cecum and retroflexed, and examination was performed to the hepatic flexure in retroflexion. Success rate, per-polyp and per-patient miss rates, and adverse events rate of retroflexion. Retroflexion was successful in 94.4% of patients. Looping in the insertion tube was the apparent cause of 89% of failed attempts. The forward view identified 634 proximal colon polyps and 497 adenomas, and retroflexion identified an additional 68 polyps and 54 adenomas, representing a per-adenoma miss rate of 9.8% and an intention-to-treat, per-patient adenoma miss rate of 4.4%. Older age, male sex, and polyps seen on the forward view predicted polyps seen on retroflexion. There were no adverse events. Single-center, uncontrolled study with only 2 endoscopists. Right-sided colon retroflexion is generally achievable and safe in our hands. The yield is comparable to that expected from a second examination in the forward view.
Publisher: Elsevier BV
Date: 02-2011
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.GTC.2013.05.015
Abstract: Colonoscopic polypectomy is fundamental to effective colonoscopy. Through its impact on the polyp-cancer sequence, colonoscopic polypectomy reduces colorectal cancer incidence and mortality. Because it eliminates electrosurgical risk, cold snaring has emerged as the preferred technique for most small and all diminutive polyps. Few clinical trial data are available on the effectiveness and safety of specific techniques. Polypectomy technique seems highly variable between endoscopists, with some techniques more effective than others are. Further research is needed to investigate operator variation in polypectomy outcomes and establish an evidence base for best practice.
Publisher: Elsevier BV
Date: 10-2010
DOI: 10.1016/J.GIE.2010.04.030
Abstract: Failures of adenoma detection diminish the effectiveness of colonoscopy. This study investigated the impact of cap-fitted colonoscopy (CFC) on the adenoma miss rate at colonoscopy. Randomized, tandem colonoscopy study. University hospital. This study involved patients undergoing elective screening or surveillance colonoscopy. Patients were randomized to undergo cap-fitted (n = 52) or regular, high-definition (n = 48) colonoscopy before undergoing a second colonoscopy by the alternate method. During CFC, a plastic cap or hood was attached to the tip of the colonoscope, which was used to flatten haustral folds and improve mucosal exposure. The primary outcome measure was the miss rate for adenomas between patients who underwent CFC first and patients who underwent regular colonoscopy first. A total of 238 adenomas were detected in 67 patients (67%), with a combined overall miss rate of 27.7%, comprising 66 missed adenomas in 38 patients. Patients undergoing initial CFC had a significantly lower miss rate for all adenomas compared with that of patients undergoing regular colonoscopy (21% vs 33%, P = .039). Miss rates with CFC were significantly lower for adenomas of ≤5 mm (22% vs 35% P = .037). There was no significant difference in per-patient miss rates between the initial CFC group (51%, n = 18) and the initial regular colonoscopy group (63%, n = 20, P = .36). Single-center study with two endoscopists. CFC reduces miss rates for all adenomas and specifically for small adenomas. ( NCT00577083).
Publisher: Wiley
Date: 31-10-2013
DOI: 10.1111/DEN.12195
Abstract: It has been reported that double-balloon colonoscopy (DBC) is useful for patients after failed colonoscopy. In most cases previously reported, expert colonoscopists have carried out DBC. However, DBC may not require significant expertise. The objective of the present study is to assess DBC carried out by an inexperienced colonoscopist in patients referred after previously incomplete colonoscopy. In a single center between June 2011 and September 2012, we enrolled 28 consecutive patients referred following incomplete conventional colonoscopy. The reported reasons for previous failed colonoscopy were severe pain during the procedure in 15, long redundant colon in 13 and sigmoid fixation in eight. Under instruction by an experienced colonoscopist, all procedures were carried out by a gastroenterology trainee with little colonoscopy experience. A double-balloon instrument with carbon dioxide insufflation was used under fluoroscopic guidance, with i.v. sedation. Cecal intubation rate, time to cecum and patient-reported pain using a visual analog scale (0 to 10) were evaluated. The trainee achieved a cecal intubation in all patients (100%) without primary involvement by the experienced colonoscopist. Time to cecum ranged from 6 min to 66 min (median time to cecum 15 min 55 s). No patients required additional sedation. Visual analogue pain scores ranged from 0/10 to 10/10 (median score 2.5/10). There were no complications. DBC may enable inexperienced colonoscopists to achieve total colonoscopy after previously incomplete conventional colonoscopy.
Publisher: Wiley
Date: 13-03-2023
DOI: 10.1111/DEN.14531
Abstract: The number of artificial intelligence (AI) tools for colonoscopy on the market is increasing with supporting clinical evidence. Nevertheless, their implementation is not going smoothly for a variety of reasons, including lack of data on clinical benefits and cost‐effectiveness, lack of trustworthy guidelines, uncertain indications, and cost for implementation. To address this issue and better guide practitioners, the World Endoscopy Organization (WEO) has provided its perspective about the status of AI in colonoscopy as the position statement. WEO Position Statement : Statement 1.1: Computer‐aided detection (CADe) for colorectal polyps is likely to improve colonoscopy effectiveness by reducing adenoma miss rates and thus increase adenoma detection Statement 1.2: In the short term, use of CADe is likely to increase health‐care costs by detecting more adenomas Statement 1.3: In the long term, the increased cost by CADe could be balanced by savings in costs related to cancer treatment (surgery, chemotherapy, palliative care) due to CADe‐related cancer prevention Statement 1.4: Health‐care delivery systems and authorities should evaluate the cost‐effectiveness of CADe to support its use in clinical practice Statement 2.1: Computer‐aided diagnosis (CADx) for diminutive polyps (≤5 mm), when it has sufficient accuracy, is expected to reduce health‐care costs by reducing polypectomies, pathological examinations, or both Statement 2.2: Health‐care delivery systems and authorities should evaluate the cost‐effectiveness of CADx to support its use in clinical practice Statement 3: We recommend that a broad range of high‐quality cost‐effectiveness research should be undertaken to understand whether AI implementation benefits populations and societies in different health‐care systems.
Publisher: Georg Thieme Verlag KG
Date: 17-02-2015
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2011
DOI: 10.1038/AJG.2011.13
Publisher: Elsevier BV
Date: 03-2015
Publisher: Elsevier BV
Date: 10-2011
Publisher: BMJ
Date: 19-02-2016
Publisher: BMJ
Date: 03-10-2016
Publisher: Future Medicine Ltd
Date: 12-2013
DOI: 10.2217/CRC.13.70
Abstract: SUMMARY Colorectal cancer remains a major cancer diagnosis, and a cause of mortality worldwide with screening and surveillance programs representing a significant healthcare commitment. The serrated pathway is responsible for 20–30% of colon cancers and evidence is accumulating for a major role in the relative failure of colonoscopy to provide high-level protection from cancer in the proximal colon. Although the significance of the serrated pathway and its precursor lesions are well established, the prevalence of the precursor lesions at colonoscopy is not. Multiple factors can impact attempts to accurately assess the prevalence of these lesions. This review discusses these factors and summarizes publications on sessile serrated adenoma and proximal serrated polyp prevalence.
Publisher: SAGE Publications
Date: 30-01-2009
Abstract: Communication failures in the complex environment of hospital care affect the quality of care and occurrence of inadvertent harm. This study investigated doctors' written communication using a s le of medical records, specifically doctors' progress notes, and the frameworks of social identity and communication accommodation theories. These records include standardized and stylized language, and are intended to record assessment and treatment of patients according to known guidelines for practice. An interpretive analysis of the language and discourse in these records revealed that doctors used medical record entries both to express their specialty identity and to negotiate intergroup conflict. Nonaccommodation and interspecialty conflict sometimes took precedence over facilitation of patient treatment and management. Thus, intergroup communication in this context can constitute a serious threat to the quality of patient care.
Publisher: BMJ
Date: 02-04-2020
DOI: 10.1136/GUTJNL-2020-321185
Abstract: Coronavirus-19 (COVID-19) caused by SARS-CoV-2 has become a global pandemic. Risk of transmission may occur during endoscopy and the goal is to prevent infection among healthcare professionals while providing essential services to patients. Asia was the first continent to have a COVID-19 outbreak, and this position statement of the Asian Pacific Society for Digestive Endoscopy shares our successful experience in maintaining safe and high-quality endoscopy practice at a time when resources are limited. Sixteen experts from key societies of digestive endoscopy in Asia were invited to develop position statements, including patient triage and risk assessment before endoscopy, resource prioritisation and allocation, regular monitoring of personal protective equipment, infection control measures, protective device training and implementation of a strategy for stepwise resumption of endoscopy services after control of the COVID-19 outbreak.
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.CGH.2010.09.013
Abstract: Colonoscopy may have a greater protective effect for distal colorectal cancer (CRC) than proximal CRC. Serrated polyps are frequently located in the proximal colon, can be missed during colonoscopy, and may progress to CRC. We investigated the prevalence and endoscopist detection rates of proximal serrated polyps in a large cohort of average risk patients undergoing screening colonoscopy. Screening colonoscopies performed by 15 attending gastroenterologists at 2 academic endoscopy units between 2000 and 2009 were reviewed. Serrated polyps included hyperplastic polyps, sessile serrated adenomas, and traditional serrated adenomas. Endoscopist-level detection rates for adenomas and serrated polyps were calculated. Pearson correlation coefficients were calculated to evaluate the associations of adenoma and proximal serrated polyp detection rates. Logistic regression was used to compare endoscopists' detection rates. A total of 11,049 polyps were detected in 6681 colonoscopies (adenomas: 5637, 51% serrated: 3984, 36% proximal serrated: 1238, 11%). The proportion of colonoscopies with at least one proximal serrated polyp was 13% (range 1%-18%). Proximal serrated polyp detection rates per colonoscopy ranged from 0.01 to 0.26. Adenoma and proximal serrated polyp detection rates per colonoscopy were strongly correlated (R = 0.76, P = .0005). The odds of detecting at least one proximal serrated polyp for in idual endoscopists ranged from 0.05 to 0.67 compared to the highest level detector. Endoscopist (P < .0001), but not patient age (P = .76) or gender (P = .95), was associated with proximal serrated polyp detection. In an average-risk screening cohort, the detection of proximal serrated polyps was highly variable and endoscopist dependent. A significant proportion of proximal serrated polyps may be missed during colonoscopy. High-quality colonoscopy is important for the detection and resection of all polyps with neoplastic potential.
Publisher: Elsevier BV
Date: 08-2012
DOI: 10.1016/J.GIE.2012.04.446
Abstract: Accurate colonoscopic assessment of colorectal polyp histology could avoid resection of distal nonadenomatous polyps and reduce costs and risk. To assess the accuracy of predicting histology by using narrow-band imaging (NBI) in real time for distal colorectal polyps. Prospective observational study. University hospital and ambulatory surgery center. This study involved 225 consecutive adults undergoing elective screening or surveillance colonoscopy. We evaluated real-time histology of 235 distal (rectosigmoid) colorectal polyps from 31 patients by using high-definition colonoscopy and NBI without optical magnification. For each polyp, the endoscopist described size, Paris classification, and surface characteristics (vascular and pit pattern, color, pseudodepression). Before resection, histology was predicted, and a level of confidence (high or low) was assigned. Sensitivity and negative predictive value of high-confidence endoscopic predictions of adenomatous versus hyperplastic histology for polyps ≤ 5 mm. The accuracy of a high-confidence endoscopic prediction was 97.7%, sensitivity for adenomatous histology 93.9%, specificity 98.4%, negative predictive value 97.9%, and positive predictive value 75.6%. The performance characteristics for predicting diminutive distal polyps (≤ 5 mm) with high confidence were sensitivity 96.0%, specificity 99.4%, negative predictive value 99.4%, and positive predictive value 96.0%. Single-center study with a single endoscopist. NBI without optical magnification is sufficiently accurate to allow distal hyperplastic polyps to be left in place without resection and small, distal adenomas to be discarded without pathologic assessment. These findings validate NBI criteria based on color, vessels, and pit characteristics for predicting real-time colorectal polyp histology.
Publisher: Elsevier BV
Date: 10-2010
DOI: 10.1016/J.GIEC.2010.07.011
Abstract: Colonoscopy is sometimes considered the preferred colorectal cancer screening modality, yet this modality may be subject to variation in operator performance more than any other screening test. Failures of colonoscopy to consistently detect precancerous lesions threaten the effectiveness of this technique for the prevention of colorectal cancer. Studies on high-level adenoma detectors under optimal conditions have begun to establish the true efficacy of colonoscopy and further widen the gap between efficacy and effectiveness. Research is required to establish the component skills, attitudes, and behaviors for high-level mucosal inspection competence necessary for training and assessment. Interventions to bridge the gap between efficacy and effectiveness are lacking, yet they should emphasize quality measurement and operate at various levels within the health system to motivate change in endoscopist behavior.
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.GIEC.2014.12.002
Abstract: Colonoscopy for average-risk colorectal cancer screening has transformed the practice of gastrointestinal medicine in the United States. However, although the dominant screening strategy, its use is not supported by randomized controlled trials. Observational data do support a protective effect of colonoscopy and polypectomy on colorectal cancer incidence and mortality, but the level of protection in the proximal colon is variable and operator-dependent. Colonoscopy by high-level detectors remains highly effective, and ongoing quality improvement initiatives should consider regulatory factors that motivate changes in physician behavior.
Publisher: Elsevier BV
Date: 11-2006
DOI: 10.1053/J.GASTRO.2006.08.038
Abstract: Sporadic colorectal cancers with a high degree of microsatellite instability are a clinically distinct subgroup with a high incidence of BRAF mutation and are widely considered to develop from serrated polyps. Previous studies of serrated polyps have been highly selected and largely retrospective. This prospective study examined the prevalence of sessile serrated adenomas and determined the incidence of BRAF and K-ras mutations in different types of polyps. An unselected consecutive series of 190 patients underwent magnifying chromoendoscopy. Polyp location, size, and histologic classification were recorded. All polyps were screened for BRAF V600E and K-ras codon 12 and 13 mutations. Polyps were detected in 72% of patients. Most (60%) were adenomas (tubular adenomas, tubulovillous adenomas), followed by hyperplastic polyps (29%), sessile serrated adenomas (SSAs 9%), traditional serrated adenomas (0.7%), and mixed polyps (1.7%). Adenomas were more prevalent in the proximal colon (73%), as were SSAs (75%), which tended to be large (64% >5 mm). The presence of at least one SSA was associated with increased polyp burden (5.0 vs 2.5 P < .0001) and female sex (P < .05). BRAF mutation was rare in adenomas (1/248 [0.4%]) but common in SSAs (78%), traditional serrated adenomas (66%), mixed polyps (57%), and microvesicular hyperplastic polyps (70%). K-ras mutations were significantly associated with goblet cell hyperplastic polyps and tubulovillous adenomas (P < .001). The prevalence of SSAs is approximately 9% in patients undergoing colonoscopy. They are associated with BRAF mutation, proximal location, female sex, and presence of multiple polyps. These findings emphasize the importance of identifying and removing these lesions for endoscopic prevention of colorectal cancer.
Publisher: Elsevier BV
Date: 11-2006
DOI: 10.1016/J.CGH.2006.07.009
Abstract: Two major mutations are defined within the hemochromatosis gene, HFE. Although the effects of the C282Y substitution have been well characterized, the clinical significance of the C282Y/H63D state remains unclear. This study assessed the phenotypic expression in C282Y/H63D subjects as compared with C282Y homozygotes. Data were obtained from 91 C282Y/H63D probands, 158 C282Y/H63D subjects identified through family screening, and 483 C282Y homozygotes. Subjects underwent clinical evaluation, genotyping, biochemical assessment, and liver biopsy examination where clinically indicated. C282Y/H63D probands had significantly less clinical and biochemical expression than C282Y homozygotes. Biochemical expression was higher in C282Y/H63D probands than in C282Y/H63D subjects identified through family screening (P < .001). Of the C282Y/H63D subjects with serum ferritin levels greater than 1000 mug/L, all had known comorbid factors that could have contributed to the increased ferritin level. Of the 51 C282Y/H63D subjects who underwent liver biopsy examination, significantly increased iron stores were present in 9 subjects and hepatic fibrosis was present in 13. Twelve of the 13 had evidence of hepatic steatosis, excess alcohol consumption, or diabetes. The mobilizable iron level was significantly higher in C282Y homozygous males than in compound heterozygous males (P < .001). Genetic screening of C282Y/H63D first-degree relatives detected 5 C282Y homozygotes. C282Y/H63D subjects referred for assessment had a high prevalence of increased iron indices but did not develop progressive clinical disease without comorbid factors such as steatosis, diabetes, or excess alcohol consumption. When fibrosis was seen, 1 or more comorbid factors almost always were present. Thus, phlebotomy therapy is warranted and cascade screening of relatives should be performed because expressing C282Y homozygotes may be detected.
Publisher: Wiley
Date: 17-10-2018
DOI: 10.1111/DEN.13272
Abstract: Colonic spasm can interfere with colonoscopy, but antispasmodic agents can cause complications. This study aimed to assess the inhibitory effect of topical lidocaine compared with a placebo control. In five tertiary-care hospitals in Japan, 128 patients requiring endoscopic resection of a colorectal lesion were enrolled and randomly and double-blindly allocated to colonoscopy with topical administration of 2% lidocaine solution 20mL (LID, n = 64) or normal saline 20mL (control, n = 64). During colonoscopy, the assigned solution was applied with a spray catheter near the lesion and the area was observed for three minutes. primary endpoint was the inhibitory effect at three time-points (1, 2 and 3 minutes after dispersion), using a three-point scale (excellent, fair, poor). Secondary endpoints were rebound spasm and adverse events. All endpoints were scored in real time. Serum lidocaine levels were measured in 32 patients (LID 16, control 16). There were no significant differences between groups in patient demographics. At all time-points, the proportion of patients with "excellent" scores was greater in LID group than control group, with significant differences observed at 2 minutes (p = 0.02) and 3 minutes (p = 0.02). In LID group, the rate of "excellent" scores increased by 12.5% at 2 minutes and was maintained at 3 minutes. Rebound spasm did not occur in LID group, compared with 15.6% of control group (p = 0.001). There were no adverse events in LID group. All serum lidocaine levels were below detectable levels. Topical lidocaine is an effective and safe method for suppressing colorectal spasm during colonoscopy (UMIN000024733).
Publisher: Springer Science and Business Media LLC
Date: 16-05-2009
DOI: 10.1007/S00535-009-0065-3
Abstract: It remains controversial whether chromocolonoscopy using indigocarmine increases the detection of colorectal polyps. We aimed to assess the impact of indigocarmine dye spray on the detection rate of adenomas and the feasibility of learning the technique in a Western practice. 400 patients were prospectively allocated into 2 groups A (n = 200): indigocarmine chromocolonoscopy was performed by a Japanese colonoscopist with expertise in chromoscopy B (n = 200): initial 100 patients (B-1), a Western colonoscopist with no previous experience of chromoscopy performed conventional colonoscopy, but with at least 10 min observation during colonoscopy withdrawal. In the next 100 patients (B-2), he performed chromocolonoscopy. All polyps found were resected. Regression analysis was used to compare the numbers of polyps detected in groups A, B-1 and B-2, whilst controlling for gender, age, indication and history of colorectal cancer. There were significant differences in the numbers of neoplastic polyps and flat adenomas between groups A and B-1 as well as between B-1 and B-2, but not between A and B-2. There was no significant difference in numbers of advanced lesions. Chromocolonoscopy (A and B-2) detected more neoplastic polyps of <or=5 mm. Chromocolonoscopy increases the detection of neoplastic polyps and flat adenomas, particularly diminutive polyps, but does not increase the detection of advanced lesions.
Publisher: Wiley
Date: 25-01-2019
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2010
DOI: 10.1038/AJG.2010.330
Abstract: Variation in the detection of both adenomas and cancers at colonoscopy is well established, and adenoma detection is a valid indicator of the quality of colonoscopy. A study reported in this issue demonstrated variable detection of serrated lesions among endoscopists. It is possible that serrated lesions are a major key to the lower level of protection provided by colonoscopy for proximal compared with the distal colon cancer, and serrated lesions may be an appropriate detection target during colonoscopy.
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1016/J.GIE.2012.03.246
Abstract: Previous studies have demonstrated the construct validity of virtual reality colonoscopy simulators by showing that they can distinguish between users according to their level of endoscopic experience. Although physical model simulators are known to simulate looping more realistically than these devices, they lack published validation evidence. To assess the construct validity of a physical model simulator, the Kyoto Kagaku Colonoscope Training Model (Kyoto Kagaku Co. Ltd, Kyoto, Japan) and to determine its suitability for assessing the insertion skill of trainee colonoscopists. Validation study 21 experienced colonoscopists and 18 novices made 2 attempts at each of 4 standard cases on the Kyoto Kagaku physical model simulator, and we compared their performance on each case. A medical simulation center in a large tertiary hospital. Completion rates, times to cecum, and peak forces applied to the colon model. Compared with novices, experienced colonoscopists had significantly higher completion to cecum rates and shorter times to cecum for each of the 4 cases (all P < .005). For 2 cases, experienced colonoscopists also exerted significantly lower peak forces than did novices (both P = .01). Two of the model's 6 "standard cases" were not included in the study. The 4 cases included in the study have construct validity in that they can distinguish between the performance of experienced colonoscopists and novices, reproducing experienced/novice differences found in real colonoscopy. These cases can be used to validly assess the insertion skill of colonoscopy trainees.
Publisher: Elsevier BV
Date: 07-2013
DOI: 10.1016/J.APERGO.2012.11.003
Abstract: A key goal for patient safety is to improve the early recognition and management of patients whose conditions deteriorate whilst in hospital. Paper-based observation charts are the main means of recording and monitoring patients' physiological stability, yet observations (e.g., blood pressure, heart rate, and respiratory rate) are not always correctly recorded or appropriately acted upon. No prior published study has applied usability heuristics to systematically compare the usability of multiple observation chart designs. In this study, five evaluators with human factors, applied psychology, or medical expertise inspected 25 observation charts for usability problems. Every chart was found to have substantial usability problems, potentially affecting the ability of hospital staff to accurately record observations or recognize patient deterioration. We proposed a new observation chart design, which avoids many of the previously observed usability problems.
Publisher: Wiley
Date: 22-02-2016
DOI: 10.1111/DEN.12625
Abstract: Optical diagnosis is an emerging paradigm in Western endoscopic practice for the colonoscopic management of diminutive polyps, and includes two complementary clinical strategies: 'resect and discard', in which diminutive high-confidence adenomas are identified, and then removed and discarded without pathological assessment and 'diagnose and leave', where diminutive high-confidence hyperplastic polyps are identified in the rectosigmoid and then left without resection or biopsy. Like other aspects of colonoscopy performance, adoption of optical diagnosis in Western practice is limited by operator dependency and variation in clinical effectiveness. There is substantial potential for optical diagnosis of colorectal neoplasia during colonoscopy to alleviate the rising costs of health care in the West. However, operator dependence in diagnostic performance together with critical system factors such as informed consent, credentialing, medical legal support and reimbursement incentives must be overcome before optical diagnosis of diminutive lesions is considered for widespread adoption in Western clinical practice.
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.GIE.2013.04.185
Abstract: A simple endoscopic classification to accurately predict deep submucosal invasive (SM-d) carcinoma would be clinically useful. To develop and assess the validity of the NBI international colorectal endoscopic (NICE) classification for the characterization of SM-d carcinoma. 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 in idual criteria by inexperienced participants, by using high-definition still images without magnification of known histology and (4) prospective validation of the in idual criteria and overall classification by inexperienced participants after training. Japanese academic unit. Performance characteristics of the NICE criteria (phase 3) and overall classification (phase 4) for SM-d carcinoma sensitivity, specificity, predictive values, and accuracy. We expanded the NICE classification for the endoscopic diagnosis of SM-d carcinoma (type 3) and established the predictive validity of its in idual components. The negative predictive values of the in idual 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). Single Japanese center, use of still images without prospective clinical evaluation. The NICE classification is a valid tool for predicting SM-d carcinomas in colorectal tumors.
Publisher: Georg Thieme Verlag KG
Date: 06-10-2015
Publisher: Springer Science and Business Media LLC
Date: 12-2015
Publisher: Elsevier BV
Date: 09-2010
DOI: 10.1016/J.GIE.2010.03.1124
Abstract: Colonoscopy with narrow-band imaging can allow real-time determination of polyp histology. To determine whether physicians with varying levels of experience can learn and apply endoscopic criteria to distinguish between adenomas and hyperplastic polyps. Prospective observational study. University teaching hospital. This study involved 37 physicians (medical residents, N = 12 gastroenterology fellows, N = 12 and gastroenterology faculty, N = 13). Small-group, 20-minute, didactic teaching sessions in which the endoscopic criteria for determining polyp histology by using narrow-band imaging were described and demonstrated. Learning outcomes were evaluated by using written pretests and posttests in which participants scored pathologically verified, high-definition polyp photographs as adenomas or hyperplastic polyps. The mean overall scores increased significantly from 47.6% correct on the pretest to 90.8% correct on the posttest (P = .0001). The overall mean percentage of responses answered don't know was significantly lower on the posttest (0.6%) compared with the pretest (20.5%, P < .0001). After training, the level of agreement was substantial (kappa = 0.69 for all participants, kappa = 0.79 for fellows). Our study did not assess for sustained improvement with time or in vivo accuracy of histological prediction during live colonoscopy. Further validation in a s le of community physicians is required. A short, didactic teaching session can achieve high accuracy and good interobserver agreement in the use of narrow-band imaging for determining the histology of colorectal polyps.
Publisher: Elsevier BV
Date: 10-2015
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.GIE.2016.11.031
Abstract: Optical diagnosis allows for real-time endoscopic assessment of colorectal polyp histology and consists of the resect and discard and diagnose and leave paradigms. This survey assessed patient acceptance of optical diagnosis and their responses to a hypothetical doomsday scenario. We conducted a 3-month cross-sectional survey of colonoscopy outpatients presenting to an Australian academic endoscopy center. A total of 981 patients completed the survey (76.0% response rate). The 60.8% of patients who supported resect and discard were more likely to be older men who co-supported diagnose and leave. Fewer patients (49.6%) supported diagnose and leave. A family history of missed cancer diagnosis (odds ratio [OR], 0.59 P = .003) was significantly associated with rejection of resect and discard, and a personal or family history of bowel cancer (OR, 0.7 P = .04) was significantly associated with rejection of diagnose and leave. In the hypothetical scenario of a cancerous polyp incorrectly left in situ leading to stage III disease, 208 (21.2%) patients would definitely ask for financial compensation, 584 (59.5%) were unsure, and 189 (19.3%) would definitely not seek compensation. The patient-proposed median value of compensation sought was $760,000 USD ($1,000,000 AUD $1 AUD = $0.76 USD). Notably, 18.5% would be willing to give optical diagnosis another chance after this error. Patient support for optical diagnosis is limited, and those who are not supporters are more likely to seek financial compensation if errors occur.
Location: United States of America
No related grants have been discovered for David Hewett.