Siwan Thomas-Gibson

Colorectal Stenting for Malignant and Benign Disease: Outcomes in Colorectal Stenting

INTRODUCTION:Self-expanding metal stents are now an established treatment for malignant colonic obstruction. Favorable outcomes have been reported both for cancer palliation and treatment of acute obstruction as a “bridge” to surgery. However, little data exists regarding the use of stents for benign colonic obstruction.METHODS:All cases of colonic stent insertion occurring between December 1996 to October 2002 were reviewed. During the study period, 36 patients with malignant obstruction and 6 patients with benign obstructive disease underwent placement of self-expandable stents using a combined endoscopic and fluoroscopic technique.RESULTS:Stent placement was successful in 36 of 42 patients (86 percent). Complications occurred in 16 of 36 patients (44 percent): migration (n = 7), reobstruction (n = 5), perforation (n = 2), fistula formation (n = 1), and stent fracture (n = 1). Stent placement was successful in 100 percent of patients with benign strictures but poststent migration was frequent (2/6).CONCLUSIONS:Stent insertion provided an effective outcome in patients with malignant colonic obstruction as a palliative and preoperative therapy. Although a relatively high migration rate was observed in patients with benign strictures, stenting was still effective in providing luminal patency (median follow-up, 7.5 months). Stenting should be considered as a first-line treatment for malignant strictures and as a potential therapy for selected benign strictures.

Development and validation of a training module on the use of narrow-band imaging in differentiation of small adenomas from hyperplastic colorectal polyps.

BACKGROUND Experts are accurate in differentiating small adenomas from hyperplastic polyps at colonoscopy by using narrow-band imaging (NBI). OBJECTIVE To prospectively evaluate the effectiveness of an NBI training module on individuals with varying colonoscopy experience. DESIGN Prospective educational evaluation study. SETTING Academic endoscopy unit. PARTICIPANTS Twenty-one participants of varying colonoscopy experience (novices, trainees, and experienced gastroenterologists) and 5 experts in NBI. INTERVENTION Participants completed a computer-based test module consisting of 30 NBI polyp images. No feedback was given. They then completed a computer-based training module on the use of NBI in the differentiation of adenomas and hyperplastic polyps. The test module was then completed a second time. MAIN OUTCOME MEASUREMENTS Construct validity (the difference in baseline accuracy on the test module between different groups of participants) and content validity (difference in accuracy achieved on the test module before and after training) of the training module. RESULTS There was a significant difference in the baseline accuracy (P < .001) between experts (0.95; 95% confidence interval [CI], 0.92-0.97), experienced colonoscopists (0.68; 95% CI, 0.68-0.74), trainees (0.75; 95% CI, 0.67-0.82), and novices (0.62; 95% CI, 0.46-0.77). Accuracy increased significantly (P < .001) for all 3 groups after training (novices 0.84; 95% CI, 0.78-0.88, trainees 0.90; 95% CI, 0.84-0.93, and experienced colonoscopists 0.84; 95% CI, 0.76-0.89). After training, the agreement was moderate at least (κ = 0.56 for novices, κ = 0.70 for trainees, and κ = 0.54 for experienced colonoscopists). LIMITATIONS This study did not assess the accuracy of optical diagnosis in routine clinical practice. CONCLUSION A short, computer-based training module can improve the diagnostic accuracy and interobserver agreement for the use of NBI to differentiate adenomas from hyperplastic polyps and could be used for the initial training in optical diagnosis.

Training and transfer of colonoscopy skills: a multinational, randomized, blinded, controlled trial of simulator versus bedside training

BACKGROUND The Olympus colonoscopy simulator provides a high-fidelity training platform designed to develop knowledge and skills in colonoscopy. It has the potential to shorten the learning process to competency. OBJECTIVE To investigate the efficacy of the simulator in training novices in colonoscopy by comparing training outcomes from simulator training with those of standard patient-based training. DESIGN Multinational, multicenter, single-blind, randomized, controlled trial. SETTING Four academic endoscopy centers in the United Kingdom, Italy, and The Netherlands. PARTICIPANTS AND INTERVENTION This study included 36 novice colonoscopists who were randomized to 16 hours of simulator training (subjects) or patient-based training (controls). Participants completed 3 simulator cases before and after training. Three live cases were assessed after training by blinded experts. MAIN OUTCOME MEASUREMENTS Automatically recorded performance metrics for the simulator cases and blinded expert assessment of live cases using Direct Observation of Procedural Skills and Global Score sheets. RESULTS Simulator training significantly improved performance on simulated cases compared with patient-based training. Subjects had higher completion rates (P=.001) and shorter completion times (P < .001) and demonstrated superior technical skill (reduced simulated pain scores, correct use of abdominal pressure, and loop management). On live colonoscopy, there were no significant differences between the 2 groups. LIMITATIONS Assessment tools for live colonoscopies may lack sensitivity to discriminate between the skills of relative novices. CONCLUSION Performance of novices trained on the colonoscopy simulator matched the performance of those with standard patient-based colonoscopy training, and novices in the simulator group demonstrated superior technical skills on simulated cases. The simulator should be considered as a tool for developing knowledge and skills prior to clinical practice.

Forty-Year Analysis of Colonoscopic Surveillance Program for Neoplasia in Ulcerative Colitis: An Updated Overview.

Objectives:This study provides an overview of the largest and longest-running colonoscopic surveillance program for colorectal cancer (CRC) in patients with long-standing 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 (1 January 2013).Results:A total of 1,375 UC patients were followed up for 15,234 patient-years (median, 11 years per patient). CRC was detected in 72 patients (incidence rate (IR), 4.7 per 1,000 patient-years). Time-trend analysis revealed that although there was significant decrease in incidence of colectomy performed for dysplasia (linear regression, R=−0.43; P=0.007), IR of advanced CRC and interval CRC have steadily decreased over past 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 past decade (χ2, P=0.045); however, its 10-year survival rate was high (79.6%). The IR of dysplasia has similarly increased (χ2, P=0.01), potentially attributable to the recent use of chromoendoscopy that was twice more effective at detecting dysplasia compared with white-light endoscopy (χ2, 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).Conclusions:Colonoscopic surveillance may have a significant role in reducing the risk of advanced and interval CRC while allowing more patients to retain their colon for longer. Given the ongoing risk of early CRC, patients with any grade of dysplasia who are managed endoscopically should be monitored closely with advanced techniques.

A comparative study of standard vs. high definition colonoscopy for adenoma and hyperplastic polyp detection with optimized withdrawal technique

Background  Colonoscopy has a known miss rate for polyps and adenomas. High definition (HD) colonoscopes may allow detection of subtle mucosal change, potentially aiding detection of adenomas and hyperplastic polyps.

Dynamic patient position changes during colonoscope withdrawal increase adenoma detection: a randomized, crossover trial

BACKGROUND Colonoscopy has a miss rate for adenomas that may partly relate to poor visualization of the colonic surface. Dynamic position changes during colonoscope withdrawal can improve luminal distension. OBJECTIVE To assess whether position changes also improve adenoma and polyp detection. DESIGN Randomized crossover clinical trial. SETTING Academic endoscopy unit. PATIENTS This study involved 130 patients who presented for routine colonoscopy. INTERVENTION Examination either entirely in the left lateral position followed by position changes (cecum to hepatic flexure, left lateral; transverse colon, supine; splenic flexure and descending colon, right lateral) or vice versa. After both examinations, polyps were removed for histopathology. MAIN OUTCOME MEASUREMENTS Proportion of patients with ≥1 polyp or adenoma detected between the hepatic flexure and the sigmoid-descending colon junction. Luminal distension was measured on a scale of 1 to 5: 1, total collapse; 5, fully distended. RESULTS At least 1 adenoma was detected in 34% of patients in colon areas in which the patient position differed from left lateral (transverse colon, splenic flexure, descending colon) compared with 23% examined with the patient in the left lateral position alone (P = .01). At least 1 polyp was detected in 52% of patients with position changes versus 34% of patients examined in the left lateral position alone (P < .001). Adenoma and polyp detection were positively correlated with an improved distension score (correlation coefficient, 0.12; P < .001). Adenomas were detected in 16% of colon areas with adequate distension scores (4 and 5) compared with 7% of those with borderline or nondiagnostic scores (1-3; P < .001). LIMITATIONS Single-operator study. CONCLUSION Dynamic position changes during colonoscope withdrawal significantly improved polyp and adenoma detection. ( CLINICAL TRIAL REGISTRATION NUMBER NCT00234650).

Leadership training to improve adenoma detection rate in screening colonoscopy: a randomised trial

Objective 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. Design 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. Results 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). Conclusions Teaching centre leaders in colonoscopy training improved important quality measures in screening colonoscopy. Trial registration number NCT01667198.

British Society of Gastroenterology/Association of Coloproctologists of Great Britain and Ireland guidelines for the management of large non-pedunculated colorectal polyps

These guidelines provide an evidence-based framework for the management of patients with large non-pedunculated colorectal polyps (LNPCPs), in addition to identifying key performance indicators (KPIs) that permit the audit of quality outcomes. These are areas not previously covered by British Society of Gastroenterology (BSG) Guidelines. A National Institute of Health and Care Excellence (NICE) compliant BSG guideline development process was used throughout and the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool was used to structure the guideline development process. A systematic review of literature was conducted for English language articles up to May 2014 concerning the assessment and management of LNPCPs. Quality of evaluated studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) Methodology Checklist System. Proposed recommendation statements were evaluated by each member of the Guideline Development Group (GDG) on a scale from 1 (strongly agree) to 5 (strongly disagree) with >80% agreement required for consensus to be reached. Where consensus was not reached a modified Delphi process was used to re-evaluate and modify proposed statements until consensus was reached or the statement discarded. A round table meeting was subsequently held to finalise recommendations and to evaluate the strength of evidence discussed. The GRADE tool was used to assess the strength of evidence and strength of recommendation for finalised statements. KPIs, a training framework and potential research questions for the management of LNPCPs were also developed. It is hoped that these guidelines will improve the assessment and management of LNPCPs.

What is the most reliable imaging modality for small colonic polyp characterization? Study of white-light, autofluorescence, and narrow-band imaging

BACKGROUND AND STUDY AIMS In vivo optical diagnosis of small colorectal polyps has potential clinical and cost advantages, but requires accuracy and high interobserver agreement for clinically acceptability. We aimed to assess interobserver variability and diagnostic performance of endoscopic imaging modalities in characterizing small colonic polyps. METHODS High quality still images of 80 polyps < 1 cm were recorded using white-light endoscopy (WLE), autofluorescence imaging (AFI) and narrow-band imaging with and without magnification (NBI and NBImag). All images were assessed for quality, prediction of polyp histology, and vascular pattern intensity (with NBI) by nine experienced colonoscopists (four experts in advanced imaging) from five UK centers. Interobserver agreement (kappa statistic), sensitivity, specificity, and accuracy were calculated compared with histopathological findings. RESULTS Interobserver agreement for predicting polyp histology using NBImag was significantly better for experts (κ = 0.63, substantial) compared with nonexperts (κ = 0.30, fair; P < 0.001), and was moderate for all colonoscopists with WLE, AFI and NBI. Interobserver agreement for vascular pattern intensity using NBI was 0.69 (substantial) for experts and 0.57 (good) for nonexperts. NBImag had higher sensitivity than WLE (experts, 0.93 vs. 0.68, P < 0.001; nonexperts, 0.90 vs. 0.52, P < 0.001) and higher overall accuracy (experts, 0.76 vs. 0.64, P = 0.003; nonexperts 0.61 vs. 0.40, P < 0.001). AFI had worse accuracy than WLE for both expert colonoscopists (0.53 vs. 0.64, P = 0.02) and nonexperts (0.32 vs. 0.40, P = 0.04). CONCLUSIONS Of the imaging modalities tested, NBImag appeared to have the best overall accuracy and interobserver agreement, although not adequate for in vivo diagnosis. NBI and AFI did not have better sensitivity, specificity, or accuracy compared with WLE.

Use of video and magnetic endoscope imaging for rating competence at colonoscopy: Validation of a measurement tool

BACKGROUND Counting the number of procedures performed provides at best a crude measure of technical competence in colonoscopy. The aim of this study was to develop and validate a qualitative and a quantitative score for measuring technical competency in colonoscopy using videotape evaluation. METHODS Eighteen endoscopists with varying levels of experience were prospectively videotaped during colonoscope insertion. The following were recorded simultaneously: a closed circuit television view showing instrument handling, the endoscopic luminal view, and a continuous display of the colonoscope configuration (magnetic endoscope imaging). Videotapes were reviewed blindly and in random order by 3 experts. Performance in 3 categories was evaluated: (1) manipulation of instrument controls (0-10), (2) manipulation of the insertion tube (0-6) and (3) depth of insertion (0-4). A global assessment of competence was given for each endoscopist. RESULTS Comparing the total scores as assessed by the 3 blinded experts, for each individual endoscopist, there were significant differences. However, there was good interobserver agreement and correlation between the individual scores and global assessment ratings of competence (p < 0.0001). CONCLUSIONS The video assessment tool described appears to measure technical competence at colonoscopy, although in its present form it lacks reliability. Refinement of the score may improve reliability and deserves further evaluation.