Siwan Thomas-Gibson

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

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Publications (81)462.96 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: National bowel cancer screening programmes have resulted in a significant shift to earlier stage colonic malignancy at diagnosis. Yet the primary treatment, colectomy, is morbid with complications in up to 40% of patients. New minimally invasive local excision techniques are being developed, but methods to assess local lymphatic staging more accurately, such as sentinel lymph node mapping, will be needed. In this video vignette we detail the use of near-infrared (NIR) laparoscopic sentinel lymph mapping in two patients with early colon cancer. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Colorectal Disease 03/2015; DOI:10.1111/codi.12950 · 2.02 Impact Factor
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    ABSTRACT: Suboptimal adenoma detection rate (ADR) at colonoscopy is associated with increased risk of interval colorectal cancer. It is uncertain how ADR might be improved. We compared the effect of leadership training versus feedback only on colonoscopy quality in a countrywide randomised trial. 40 colonoscopy screening centres with suboptimal performance in the Polish screening programme (centre leader ADR ≤25% during preintervention phase January to December 2011) were randomised to either a Train-Colonoscopy-Leaders (TCLs) programme (assessment, hands-on training, post-training feedback) or feedback only (individual quality measures). Colonoscopies performed June to December 2012 (early postintervention) and January to December 2013 (late postintervention) were used to calculate changes in quality measures. Primary outcome was change in leaders' ADR. Mixed effect models using ORs and 95% CIs were computed. The study included 24 582 colonoscopies performed by 38 leaders and 56 617 colonoscopies performed by 138 endoscopists at the participating centres. The absolute difference between the TCL and feedback groups in mean ADR improvement of leaders was 7.1% and 4.2% in early and late postintervention phases, respectively. The TCL group had larger improvement in ADR in early (OR 1.61; 95% CI 1.29 to 2.01; p<0.001) and late (OR 1.35; 95% CI 1.10 to 1.66; p=0.004) postintervention phases. In the late postintervention phase, the absolute difference between the TCL and feedback groups in mean ADR improvement of entire centres was 3.9% (OR 1.25; 95% CI 1.04 to 1.50; p=0.017). Teaching centre leaders in colonoscopy training improved important quality measures in screening colonoscopy. NCT01667198. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to
    Gut 02/2015; DOI:10.1136/gutjnl-2014-307503 · 13.32 Impact Factor
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    ABSTRACT: Introduction This study provides an overview of the longest-running colonoscopic surveillance programs for colorectal cancer (CRC) in patients with ulcerative colitis (UC). Methods Data were obtained from medical records, endoscopy and histology reports. Primary end points were defined as death, colectomy, withdrawal from surveillance, or censor date (January 1, 2013). Results A total of 1,375 patients were followed-up for 15,234 patient-years (median, 11 years per-patient). Cancer was detected in 72 patients (incidence rate (IR), 4.7 per 1,000 patient-years). Time-trend analysis revealed that while there was significant decrease in incidence of colectomy for dysplasia (linear regression, R= -0.43; P=0.007), IR of advanced CRC and interval CRC have steadily decreased over last four decades (Pearson’s correlation, -0.99; P=0.01 for both trends). The IR of early CRC has increased 2.5-fold in the current decade compared with last decade (Chi-squared, P=0.05), however, its 10-year survival rate was high (79.6%). The IR of dysplasia has similarly increased (P=0.01), potentially attributable to recent use of chromoendoscopy, which was twice more effective at detecting dysplasia compared with white-light endoscopy (P<0.001). CRCs were frequently accompanied by synchronous CRC or spatially distinct dysplasia (37.5%). Finally, the risk of CRC was not significantly different between “indefinite” or low-grade dysplasia (log-rank, P= 0.78). Conclusion Colonoscopic surveillance may have a significant role in reducing the risk of advanced and interval CRC while allowing patients to retain their colon. Given the ongoing risk of early CRC, patients with any grade of dysplasia who are managed endoscopically should be monitored closely with advanced techniques.
    The American Journal of Gastroenterology 01/2015; · 9.21 Impact Factor
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    ABSTRACT: To investigate whether novel, non-technical skills training for Bowel Cancer Screening (BCS) endoscopy teams enhanced patient safety knowledge and attitudes. A novel endoscopy team training intervention for BCS teams was developed and evaluated as a pre-post intervention study. Four multi-disciplinary BCS teams constituting BCS endoscopist(s), specialist screening practitioners, endoscopy nurses and administrative staff (A) from English BCS training centres participated. No patients were involved in this study. Expert multidisciplinary faculty delivered a single day's training utilising real clinical examples. Pre and post-course evaluation comprised participants' patient safety awareness, attitudes, and knowledge. Global course evaluations were also collected. Twenty-three participants attended and their patient safety knowledge improved significantly from 43%-55% (P ≤ 0.001) following the training intervention. 12/41 (29%) of the safety attitudes items significantly improved in the areas of perceived patient safety knowledge and awareness. The remaining safety attitude items: perceived influence on patient safety, attitudes towards error management, error management actions and personal views following an error were unchanged following training. Both qualitative and quantitative global course evaluations were positive: 21/23 (91%) participants strongly agreed/agreed that they were satisfied with the course. Qualitative evaluation included mandating such training for endoscopy teams outside BCS and incorporating team training within wider endoscopy training. Limitations of the study include no measure of increased patient safety in clinical practice following training. A novel comprehensive training package addressing patient safety, non-technical skills and adverse event analysis was successful in improving multi-disciplinary teams' knowledge and safety attitudes.
    World Journal of Gastroenterology 12/2014; 20(46):17507-15. DOI:10.3748/wjg.v20.i46.17507 · 2.43 Impact Factor
  • United European Gastroenterology Week; 10/2014
  • United European Gastroenterology Week, Vienna, Austria; 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.
    10/2014; 5(4):260-265. DOI:10.1136/flgastro-2013-100393
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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. DOI:10.1136/gutjnl-2014-307263.327 · 13.32 Impact Factor
  • Digestive Disease Week, Chicago; 05/2014
  • Gastrointestinal Endoscopy 05/2014; 79(5):AB233-AB234. DOI:10.1016/j.gie.2014.05.113 · 4.90 Impact Factor
  • Gastroenterology 05/2014; 146(5-5):S-118. DOI:10.1016/S0016-5085(14)60424-8 · 12.82 Impact Factor
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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
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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; 261(1). DOI:10.1097/SLA.0000000000000437 · 7.19 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; 16(6). DOI:10.1111/codi.12475 · 2.02 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.
    10/2013; 5(10):468-75. DOI:10.4253/wjge.v5.i10.468
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    Gut 06/2013; 77(5):AB132–AB133. DOI:10.1016/j.gie.2013.04.033 · 13.32 Impact Factor
  • Gut 06/2013; 62(Suppl 1):A1. DOI:10.1136/gutjnl-2013-304907.001 · 13.32 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.
    06/2013; 4:244-248. DOI:10.1136/flgastro-2013-100331
  • K. Patel, S. Thomas-Gibson, O. D. Faiz, M. D. Rutter
    Gut 05/2013; 62(Suppl 1):A149. DOI:10.1016/j.gie.2013.03.800 · 13.32 Impact Factor

Publication Stats

671 Citations
462.96 Total Impact Points


  • 2002–2015
    • St. Mark's Hospital
      Harrow, England, United Kingdom
  • 2008–2014
    • Imperial College London
      • Section of Biosurgery and Surgical Technology
      Londinium, England, United Kingdom
    • St. Mark's Hospital
      Salt Lake City, Utah, United States
  • 2009–2012
    • WWF United Kingdom
      Londinium, England, United Kingdom
  • 2007
    • Royal Melbourne Hospital
      Melbourne, Victoria, Australia