Siwan Thomas-Gibson

St. Mark's Hospital, Harrow, England, United Kingdom

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Publications (72)308.29 Total impact

  • United European Gastroenterology Week, Vienna, Austria; 10/2014
  • United European Gastroenterology Week; 10/2014
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    M Matharoo, S Thomas-Gibson, A Haycock, N Sevdalis
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    ABSTRACT: Patient safety and quality improvement are increasingly prioritised across all areas of healthcare. Errors in endoscopy are common but often inconsequential and therefore go uncorrected. A series of minor errors, however, may culminate in a significant adverse event. This is unsurprising given the rising volume and complexity of cases coupled with shift working patterns. There is a growing body of evidence to suggest that surgical safety checklists can prevent errors and thus positively impact on patient morbidity and mortality. Consequently, surgical checklists are mandatory for all procedures. Many UK hospitals are mandating the use of similar checklists for endoscopy. There is no guidance on how best to implement endoscopy checklists nor any measure of their usefulness in endoscopy. This article outlines lessons learnt from innovating service delivery in our unit.
    Frontline gastroenterology. 10/2014; 5(4):260-265.
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    ABSTRACT: Although colonoscopy is considered the optimal procedure for bowel cancer screening, it remains an imperfect tool for cancer prevention, due to missed adenomas and early cancers. Optimal imaging modalities, innovative scopes and accessories (cap-assisted colonoscopy) have attempted to decrease the adenoma miss rate. Adenoma detection rates (ADR) have been shown to be a key performance indicator METHODS: Endocuff-vision is a simple accessory mounted at the end of the scope with a proximal row of 6mm length soft plastic, finger-like projections. During scope insertion, these projections invert towards the shaft of the tube and during withdrawal they evert to hold back the colonic folds augmenting the forward endoscopic views. ADRs were recorded and evaluated for screening colonoscopy procedures before and after introduction of Endocuff-vision.
    Gut 06/2014; 63(Suppl 1):A152-A153. · 10.73 Impact Factor
  • Digestive Disease Week, Chicago; 05/2014
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    ABSTRACT: Background Until recently a finding of dysplasia arising within segment of bowel affected by ulcerative colitis (UC) was an indication for colectomy. However, some dysplastic lesions are discrete and endoscopically resectable. Long-term follow-up data for these selected patients is currently limited. The aim of this study was to evaluate the long term outcomes of patients with UC who have had an endoscopic resection of dysplasia within segment of bowel affected by colitis. Methods Patients who had a surveillance colonoscopy for UC at St Mark's Hospital between 1998 and 2008 and had an endoscopic resection of dysplastic lesions were identified from the endoscopic and histology databases. Clinical notes, endoscopy and histopathology reports were reviewed. Results One hundred patients met the inclusion criteria (male: female = 66: 34). Eighty-seven had extensive and 13 left-sided colitis, with median disease duration of 24 (IQR 13–33). The median age at disease onset and time of dysplasia diagnosis was 34 (IQR 27–48) and 61 (IQR 54–69) years old, respectively. There were 121 discrete lesions in 100 patients (Ip (60), Is (36), IIa (3), IIb (4), IIa/c (1), LST (1), and 16 were described as “appearance suspicious for DALM (Paris classification not recorded)” but which were also resected endoscopically. Median size was 8 mm (IQR 4–15). Lesions were removed using snare polypectomy (43), EMR (29), hot biopsy (20) or ESD (3) techniques. Histology showed LGD in 111 lesions and HGD in 10 lesions: 36 (30%) favoured UC-associated dysplasia, 56 (46%) favoured adenoma, and 29 (24%) lesions were inconclusive between dysplasia and adenoma. Median duration of follow up was 70 months (IQR 53–89). Overall, two cancers were detected during that time: one in same and one in distant segment to the previous dysplasia. The proportion of patients who developed dysplasia recurrence was 24% with median duration to recurrence of 41 months (IQR=16–55). Nineteen patients (19%) had recurrence to the same grade of dysplasia that was initially treated: three patients had colectomy (2 LGDs and 1 with no dysplasia), two patients died from unrelated cause, and 14 patients are still on endoscopic follow-up. Four patients (4%) have progressed from LGD to HGD which were all detected during surveillance: three patients had colectomy (Duke's A CRC, LGD, and indeterminate dysplasia, respectively), and one patient refused surgery whose latest colonoscopy showed LGD. One patient was lost in follow up for 5 years and subsequent colonoscopy detected Duke's C cancer. Conclusion Patients with endoscopically resectable, well circumscribed dysplastic lesions within the segment of colitis have a good outcome with endoscopic treatment with close surveillance.
    European Crohn's Colitis Organisation, Copenhagen; 02/2014
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    ABSTRACT: Background While it is well recognised that patients with ulcerative colitis (UC) have an increased risk of colorectal cancer (CRC), the precise magnitude and the proportion of patients progressing to CRC from pre-malignant neoplastic lesions is still being debated. This study reports on data collected from patients with endoscopically and histologically confirmed extensive UC over a 40-year period from a tertiary centre in the UK. Methods A retrospective analysis of UC patients enrolled in long-term surveillance at St Marks Hospital, UK was performed. Data were obtained from the prospective surveillance database, medical records, surgical, endoscopy and histology reports. The primary end point was defined as death, colectomy, withdrawal from surveillance, or census date (January 1, 2013). Results Since 1971, a total of 1,375 patients underwent 8,623 (median = 5, IQR 3–8) colonoscopies during 17,444 patient-years of follow up. The median follow up duration was 10 years (IQR 6–15 years), and 857 patients were still on the surveillance program as of January 1, 2013. Median age of UC onset was 30 years (IQR 22–40). A total of 318 (23.1%) patients developed neoplasia of which 69 (5%) had CRC. The proportion of patients who had progressed to CRC for each type of neoplasia during surveillance was: adenoma (3/79, 3.8%), indefinite dysplasia (12/49, 24.5%), LGD (19/131, 14.5%), and HGD (8/27, 30%). Median age and disease duration at the time of CRC diagnosis was 55 years (IQR 49–63) and 22 years (IQR 14–29), respectively. The locations of CRCs were: distal to splenic flexure (40, 58%), proximal to splenic flexure (24, 35%), multifocal CRC involving both proximal and distal colon (3, 4%), or unidentified (2, 3%). Surgical specimen revealed that 21 (30%) of CRCs were accompanied by at least one or more focus of DALM, of which 6 (8.4%) were multi-focal CRCs affecting two or more segments of colorectum. Within surveillance, the cumulative incidence of CRC by disease duration was 0.2% at 10 years, 2.6% at 20 years, 7.3% at 30 years, 10.1% at 40 years and 13.1% at 50 years. Conclusion The overall incidence of CRC, even among patients with extensive UC at the tertiary referral centre, was considerably lower than reports from other earlier published studies. However, neoplasia in any form (i.e. adenoma, LGD, HGD, or CRC) was common, eventually affecting almost 1 in 4 patients undergoing surveillance. Given the variable rates of progression from dysplasia to CRC and relatively high incidence of multifocal lesions, patients with any grade of dysplasia require close monitoring and a careful pan-colonic examination to ensure that no lesions are missed.
    European Crohn's Colitis Organisation, Copenhagen; 02/2014
  • Gastroenterology 01/2014; 146(5):S-118. · 12.82 Impact Factor
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    ABSTRACT: To validate the delivery and efficacy of the national laparoscopic colorectal surgery "training the trainer" (Lapco TT) curriculum. The National Training Programme in Laparoscopic Colorectal Surgery designed the Lapco TT curriculum to improve, standardize, and benchmark the quality of training. Evidence for such courses rarely extends beyond subjective feedback. The Lapco TT curriculum tailors key teaching skills for laparoscopic colorectal surgery: training structure, skills deconstruction, trainer intervention, and performance enhancing feedback. Ten Lapco TT courses were delivered to 65 national Lapco trainers since 2010. The course was validated at Kirkpatrick's 4 levels of evaluation: (i) pre- and post-course interviews reflecting initial reaction; (ii) training quality assessment on simulated scenarios using the Structured Training Trainer Assessment Report (STTAR) tool; (iii) follow-up interviews at 4 to 6 months; and (iv) delegate performance ratings, by their trainees, using the mini-STTAR and the delegates' trainees learning curves before and after the course. There were significant improvements in training in the post-course simulated scenario, especially in the "set" (P < 0.001). Delegates described improved framework and structure in their native training environment, which aided difficult training situations. Findings mirrored in performance ratings by their trainees: overall (4.37 vs 4.46, P = 0.040), agreed learning points (3.65 vs 4.00, P = 0.042), encouraged self-reflection (3.67 vs 3.94, P = 0.046), and encouraged team awareness (3.53 vs 4.05, P = 0.045). The learning curve of delegates' trainees improved after the course. The Lapco TT curriculum improved training performance in the short- and long-term, provided a structured training framework, and enhanced the learning curve of delegates' trainees.
    Annals of surgery 12/2013; · 7.90 Impact Factor
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    ABSTRACT: Serrated polyposis is a condition of the colon characterised by multiple serrated polyps. This review aims to provide a practical guide to the day-to-day management of serrated polyposis including diagnosis, endoscopic identification of serrated polyps, surveillance, the role of endoscopic and surgical management and screening of family members. The literature was searched using Pubmed and Medline databases for the terms "serrated polyp, serrated polyposis, hyperplastic polyposis". English language abstracts were read and the full article was retrieved if relevant to the review. Expert opinion from the authors was also sort. Advances in our knowledge of the molecular pathways involved in serrated polyposis and an improved clinical picture of the disease from retrospective studies have led to better understanding of its pathogenesis and natural history. However there are still areas not answered by the literature, and hence empirical management or expert opinion has to be followed. Improvements in our understanding of serrated polyposis together with improvements in endoscopic equipment and technique have enabled the endoscopist to be at the forefront of managing this condition from diagnosis to endoscopic surveillance and control of the polyps. This article is protected by copyright. All rights reserved.
    Colorectal Disease 11/2013; · 2.08 Impact Factor
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    ABSTRACT: Measuring quality is a current need of medical services either to assess their cost-effectiveness or to identify discrepancies requiring refinement. With the advent of bowel cancer screening and increasing patient awareness of bowel symptoms, there has been an unprecedented increase in demand for colonoscopy. Consequently, there is an expanding open-discussion on missed rates of cancer or precancerous polyps during diagnostic/screening colonoscopy and on the rate of adverse events related to therapeutic colonoscopy. Delivering a quality colonoscopy service is therefore a healthcare priority. Colonoscopy is a multi-step process and therefore assessment of all aspects of the procedure must be addressed. Quality in colonoscopy refers to a combination of many patient-centered technical and non-technical skills and knowledge aiming to patient's safety and satisfaction through a continuous effort for improvement. The benefits of this endless process are hiding behind small details which can eventually make the difference in colonoscopy. Identifying specific quality metrics help to define and shape an optimal service and forms a secure basis of improvement. Τhis paper does not aim to give technical details on how to perform colonoscopy but to summarize what to measure and when, in accordance with the current identified quality indicators and standards for colonoscopy.
    World journal of gastrointestinal endoscopy. 10/2013; 5(10):468-75.
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    Gut 06/2013; 77(5):AB132–AB133. · 10.73 Impact Factor
  • Gut 06/2013; 62(Suppl 1):A1. · 10.73 Impact Factor
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    ABSTRACT: Introduction Endoscopists are now expected to perform polypectomy routinely. Colonic polypectomy varies in difficulty, depending on polyp morphology, size, location and access. The measurement of the degree of difficulty of polypectomy, based on polyp characteristics, has not previously been described. Objective To define the level of difficulty of polypectomy. Methods Consensus by nine endoscopists regarding parameters that determine the complexity of a polyp was achieved through the Delphi method. The endoscopists then assigned a polyp complexity level to each possible combination of parameters. A scoring system to measure the difficulty level of a polyp was developed and validated by two different expert endoscopists. Results Through two Delphi rounds, four factors for determining the complexity of a polypectomy were identified: size (S), morphology (M), site (S) and access (A). A scoring system was established, based on size (1–9 points), morphology (1–3 points), site (1–2 points) and access (1–3 points). Four polyp levels (with increasing level of complexity) were identified based on the range of scores obtained: level I (4–5), level II (6–9), level III (10–12) and level IV (>12). There was a high degree of interrater reliability for the polyp scores (interclass correlation coefficient of 0.93) and levels (κ=0.888). Conclusions The scoring system is feasible and reliable. Defining polyp complexity levels may be useful for planning training, competency assessment and certification in colonoscopic polypectomy. This may allow for more efficient service delivery and referral pathways.
    Frontline Gastroenterology. 06/2013; 4:244-248.
  • K. Patel, S. Thomas-Gibson, O. D. Faiz, M. D. Rutter
    Gut 05/2013; 62(Suppl 1):A149. · 10.73 Impact Factor
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    ABSTRACT: BACKGROUND: Colonoscopy reduces colorectal cancer mortality and morbidity principally by the detection and removal of colon polyps. It is important to retrieve resected polyps to be able to ascertain their histologic characteristics. OBJECTIVE: The aim of the study was to evaluate the cause of polyp retrieval failure. DESIGN: Bowel cancer screening colonoscopy data were collected prospectively. SETTING: The Bowel Cancer Screening Program in the National Health Service. PATIENTS: Screening participants were referred to our screening center after a positive fecal occult blood test result. INTERVENTION: A total of 4383 polyps were endoscopically removed from 1495 patients from October 2006 to February 2011. MAIN OUTCOME MEASUREMENTS: The number, size, shape, and location of polyps; polyp removal method; quality of bowel preparation; total examination time; and insertion and withdrawal times in collected data were examined retrospectively. RESULTS: The polyp retrieval rate was 93.9%, and the failure rate was 6.1%, thus 267 polyps were not retrieved. In univariate analysis, factors affecting polyp retrieval failure were small polyp size, sessile polyps, and cold snare polypectomy (P < .001). Polyp retrieval was less successful in the proximal colon (P = .002). In multivariate analysis, polyp size and method of removal were independent risk factors for polyp retrieval failure (P < .001). LIMITATIONS: Retrospective study. CONCLUSION: Small polyp size and cold snare removal were found to be significantly associated with polyp retrieval failure. It was difficult to retrieve small, sessile, and proximal colon polyps. Optical diagnosis could be an efficacious option as a surrogate for histologic diagnosis for these lesions in the near future.
    Gastrointestinal endoscopy 12/2012; · 6.71 Impact Factor
  • Kinesh Patel, Sarah Marshall, Siwan Thomas-Gibson
    Clinical medicine (London, England) 12/2012; 12(6):580-2. · 1.32 Impact Factor
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    ABSTRACT: The development of a structured virtual reality (VR) training curriculum for colonoscopy using high-fidelity simulation. Colonoscopy requires detailed knowledge and technical skill. Changes to working practices in recent times have reduced the availability of traditional training opportunities. Much might, therefore, be achieved by applying novel technologies such as VR simulation to colonoscopy. Scientifically developed device-specific curricula aim to maximize the yield of laboratory-based training by focusing on validated modules and linking progression to the attainment of benchmarked proficiency criteria. Fifty participants comprised of 30 novices (<10 colonoscopies), 10 intermediates (100 to 500 colonoscopies), and 10 experienced (>500 colonoscopies) colonoscopists were recruited to participate. Surrogates of proficiency, such as number of procedures undertaken, determined prospective allocation to 1 of 3 groups (novice, intermediate, and experienced). Construct validity and learning value (comparison between groups and within groups respectively) for each task and metric on the chosen simulator model determined suitability for inclusion in the curriculum. Eight tasks in possession of construct validity and significant learning curves were included in the curriculum: 3 abstract tasks, 4 part-procedural tasks, and 1 procedural task. The whole-procedure task was valid for 11 metrics including the following: "time taken to complete the task" (1238, 343, and 293 s; P < 0.001) and "insertion length with embedded tip" (23.8, 3.6, and 4.9 cm; P = 0.005). Learning curves consistently plateaued at or beyond the ninth attempt. Valid metrics were used to define benchmarks, derived from the performance of the experienced cohort, for each included task. A comprehensive, stratified, benchmarked, whole-procedure curriculum has been developed for a modern high-fidelity VR colonoscopy simulator.
    Annals of surgery 06/2012; 256(1):188-92. · 7.90 Impact Factor
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    ABSTRACT: There is a gap in the formal assessment of technical skills in polypectomy that is now considered an integral part of colonoscopy. Polypectomy has been shown to reduce the incidence of colorectal cancer but does have associated complications. Polypectomy competency assessment should arguably be a part of the certification process for all endoscopists. A polypectomy competency assessment tool (Direct Observation of Polypectomy Skills [DOPyS]) has been developed and its reliability examined. This study examined the ability of the DOPyS to reliably distinguish between endoscopists with different levels of experience, ie, its construct validity. To determine the construct validity of the DOPyS. Videos of 32 polypectomies (endoscopic view only) were collected from 2 expert (> 1000 colonoscopies) endoscopists (17 polyps) and 6 intermediate-level (100-500 colonoscopies) endoscopists (15 polyps). The videos were edited to include only the entire polypectomy procedure, arranged in random order, and assessed blindly by 4 experienced endoscopists, only 2 of whom were familiar with polypectomy assessment by using the DOPyS before scoring. The differences in overall competency scores (range 1-4; competency, scores ≥ 3) for the expert and intermediate groups were compared by using the Fisher exact test. Single center. The analysis suggested that both trained assessors familiar with the DOPyS could reliably distinguish between the expert and intermediate endoscopists (P = .049 and P < .001), with the expert group scoring higher than the intermediate one. For the assessors with no previous experience of the DOPyS, no such difference could be seen (P = .71 and P = .15). Small sample and polyp size. The results of the analysis suggested that the DOPyS could reliably differentiate between polypectomies performed by endoscopists of different levels of experience, but only if the assessors were trained in the use of the assessment tool. Training is therefore required to use this tool reliably.
    Gastrointestinal endoscopy 12/2011; 75(3):568-75. · 6.71 Impact Factor
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    ABSTRACT: Despite its ubiquitous use over the past 4 decades, there is no structured, formal method with which to assess polypectomy. To develop and validate a new method with which to assess competency in polypectomy. Polypectomy underwent task deconstruction, and a structured checklist and global assessment scale were developed (direct observation of polypectomy skills [DOPyS]). Sixty bowel cancer screening polypectomy videos were randomly chosen for analysis and were scored independently by 7 expert assessors by using DOPyS. Each parameter and the global rating were scored from 1 to 4 (scores ≥3 = competency). The scores were analyzed by using generalizability theory (G theory). Multicenter. Fifty-nine of the 60 videos were assessable and scored. The majority of the assessors agreed across the pass/fail divide for the global assessment scale in 58 of 59 (98%) polyps. For G-theory analysis, 47 of the 60 videos were analyzed. G-theory analysis suggested that DOPyS is a reliable assessment tool, provided that it is used by 2 assessors to score 5 polypectomy videos all performed by 1 endoscopist. DOPyS scores obtained in this format would reflect the endoscopist's competence. Small sample and polyp size. This study is the first attempt to develop and validate a tool designed specifically for the assessment of technical skills in performing polypectomy. G-theory analysis suggests that DOPyS could reliably reflect an endoscopist's competence in performing polypectomy provided a requisite number of assessors and cases were used.
    Gastrointestinal endoscopy 06/2011; 73(6):1232-9.e2. · 6.71 Impact Factor

Publication Stats

505 Citations
308.29 Total Impact Points

Top Journals

Institutions

  • 2002–2014
    • St. Mark's Hospital
      Harrow, England, United Kingdom
  • 2008–2013
    • Imperial College London
      • Section of Biosurgery and Surgical Technology
      Londinium, England, United Kingdom
    • St. Mark's Hospital
      Salt Lake City, Utah, United States