Feasibility and economic assessment of chromocolonoscopy for detection of proximal serrated neoplasia within a population-based colorectal cancer screening programme (CONSCOP): an open-label, randomised controlled non-inferiority trial.

BACKGROUND: Most post-colonoscopy interval colorectal cancers are proximal; serrated polyps are often precursors to these cancers and are considered difficult to detect. We assessed the safety, feasibility, and economic effect of chromocolonoscopy on detection of proximal serrated neoplasia. METHODS: We did an open-label, multicentre, randomised, controlled non-inferiority trial including patients from Bowel Screening Wales centres. Participants who tested positive for faecal occult blood and who were eligible for and considered fit to have colonoscopy (patients with known cases of polyposis syndromes, Lynch syndrome, and chronic inflammatory disease were excluded) were randomly assigned (1:1; with the use of minimisation, stratified by centre with an 80:20 random element) to either standard white light colonoscopy (standard group) or chromocolonoscopy (indigo carmine dye [0·2%]; chromocolonoscopy group) using a secure, internet-based, computerised, randomisation system that used centralised, dynamic allocation. Participants were followed up for 1 year and data from index colonoscopies and associated clearance procedures were analysed. All proximal polyps were reviewed by an expert pathologist panel. The main outcome on which power was based was time taken to perform the colonoscopy procedure, defined as from the time when the scope was inserted to withdrawal from the anus, assessed in the per-protocol population. The non-inferiority margin was 15 min. This trial is complete and is registered with ClinicalTrials.gov, number NCT01972451. FINDINGS: Between Nov 20, 2014, and June 16, 2016, 741 (72%) of 1031 patients screened were eligible and consented: 360 were randomly assigned to white light colonoscopy and 381 to chromocolonoscopy. In the chromocolonoscopy group, the procedure took a mean of 36·8 min (SD 15·0), compared with a mean of 30·6 min (13·7) in the standard group (mean difference 6·3 min [95% CI 4·2-8·4] longer with chromocolonoscopy than in the standard group). The mean difference was within the prespecified non-inferiority margin. Detection rates for proximal serrated lesions were significantly higher in the chromocolonoscopy group than in the control group (45 [12%] of 381 patients vs 23 [6%] of 360 patients; odds ratio 1·96 [95% CI 1·16-3·32]; p=0·012). Serious adverse events (four cases of postpolypectomy bleeding [two in each group], and one case of anxiety and hyperventilation [in the chromocolonoscopy group]), colonoscopy quality measures, comfort scores, and sedation were similar between groups. INTERPRETATION: Chromocolonoscopy is feasible within a population-based colorectal cancer screening programme, is safe, and has significantly increased detection of proximal serrated neoplasia and other polyp types compared with standard colonoscopy. Larger randomised trials of chromocolonoscopy, powered for improved detection of significant serrated polyps and for longer-term follow-up to investigate the effect on reduction of interval cancers within screening populations, are warranted. FUNDING: Health and Care Research Wales (RfPPB-1021).

Assessment of technical parameters and skills training to inform a simulation-based training program for semi-automated robotic colonoscopy.

Background and study aims Video-colonoscopy, despite being the gold-standard for diagnosis of colorectal lesions, has limitations including patient discomfort and risk of complications. This study assessed training characteristics and acceptability in operators of a new robotic colonoscope (RC). Materials and methods Participants (n = 9) with varying degrees of skill and background knowledge in colonoscopy performed colonoscopies with a RC on a simulation-based training model. Quantitative procedure-related and qualitative operator-related parameters were recorded. Results Polyp detection rate was highest in the novice group (91.67 %) followed by experts (86.11 %), then equally, trainees and video gamers (79.17 %). Four participants repeated the procedure at a follow-up session. Each participant improved cecal intubation time and had the same or higher polyp detection rate. The potential role for RC was identified for an out-of-hospital environment and as a novel diagnostic tool. Conclusions Results from this pilot suggest that operators at all skill levels found the RC acceptable and potentially useful as a diagnostic tool. Acquisition of skills with RC seems to improve rapidly to a clinically relevant level with simulation-based training.

Retroperitoneal Fibrosis as a Cause of Chylous Ascites.

Retroperitoneal fibrosis is a rare condition characterized by chronic inflammation and marked fibrosis of the retroperitoneal tissue, often leading to entrapment of abdominal organs. We report a 69-year-old white man who presented with a 5-week history of gradual onset of progressive abdominal distension. He had no history or risk factors for an underlying liver condition. Ascites and a retroperitoneal mass encasing the major abdominal vessels were revealed on imaging. Biopsies of the mass confirmed the presence of retroperitoneal fibrosis, and the ascitic fluid was milky, consistent with chylous ascites. We discuss this rare presentation and the challenges of treatment for chylous ascites caused by RPF, including the role for supportive treatment.

A rare case of iron deficiency.

Giant lipomas of the stomach are very rare, accounting for less than 3% of all benign tumors of the stomach. A clear-cut endoscopic differentiation between gastric lipomas and other submucosal neoplasms is not feasible, because routine endoscopic gastric biopsies do not reach the submucosal layer. Gastric submucosal lipomas can cause gastric ulceration as in the case presented below and in rare instances this may in turn promote gastric cancer. Therefore, complete pretreatment diagnostic evaluation is needed. We present a 52-year-old man with a 6-month history of epigastric discomfort, early satiety, decreased appetite, and dyspepsia. His weight was noted to be stable and he was iron deficient (hemoglobin 11.5 g/dl and ferritin of 5 g/dl). His past history included a gastric ulcer found on endoscopy 5 years ago for which he was on omeprazole 40 mg once a day, hypertension, hypercholesterolemia, and diabetes. Clinical examination revealed central obesity with divarification of recti muscles. He underwent a colonoscopy that was normal, and an oesophago-gastro-duodenoscopy that revealed a smooth extrinsic indentation of the anterior aspect of the distal stomach at around 50 cm. Biopsies of this were normal. A computed tomography scan was obtained () that demonstrated a 14 by 15-cm fatty tumor arising from the distal stomach with a couple of 5-mm nodes adjacent to tumor and no distant metastasis representing either a lipoma, liposarcoma or gastrointestinal stromal tumours. He subsequently underwent a subtotal gastrectomy. Macroscopically, the antrum was distorted by a huge submucosal intramural tumor mass. The antral mucosa was stretched over its surface and bore a central 15-mm ulcer surrounded by a raised border (). Microscopic examination confirmed an ulcerated benign submucosal lipoma. Our patient was symptomatic with a large gastric lipoma that necessitated surgical excision. Following surgery his postoperative recovery was uneventful, and he was asymptomatic when reviewed 4 weeks later. This case demonstrates a rare case of gastric lipoma causing gastric epithelial ulceration leading to iron deficiency.