Odds of Incomplete Colonoscopy in Colorectal Cancer Screening Based on Socioeconomic Status

The aim of this study is to investigate the association between socioeconomic status (SES) and the risk of having an incomplete colonoscopy (IC) in the Danish Colorectal Cancer (CRC) Screening Program. In this register-based study we included 71,973 participants who underwent colonoscopy after a positive fecal immunochemical test in the Danish CRC Screening Program. The main exposure, SES, was defined by income and education, and the outcome by complete or incomplete colonoscopy. Among the participants, 5428 (7.5%) had an incomplete colonoscopy. The odds ratio (OR) for ICs due to inadequate bowel preparation was 1.67 (95% CI: 1.46; 1.91) for income in the 1 quartile compared to income in the 4th quartile. ORs for income in the 2nd quartile was 1.38 (95% CI: 1.21; 1.56) and 1.17 (95% CI: 1.03; 1.33) for income in the 3rd quartile. For the educational level, an association was seen for high school/vocational education with an OR of 0.87 (95% CI: 0.79; 0.97) compared to higher education. For ICs due to other reasons, the level of income was associated with the risk of having an IC with an OR of 1.19 (95% CI: 1.05; 1.35) in the 1st quartile and an OR of 1.19 (95% CI: 1.06; 1.34) in the 2nd quartile. For the educational level, there were no significant associations. Low income is associated with high risk of having an IC, whereas educational level does not show the same unambiguous association.

995 Clinical Outcomes Following Incomplete Colonoscopy

Introduction Following incomplete colonoscopy (IC) it is reported that there is up to five-fold increased risk of colorectal cancer. Our aim was to determine the final clinical outcome for patients with a prior IC. Method A multi-centre retrospective observational study involving three endoscopy units. All consecutive patients having colonoscopy from over 18 months were analysed. Exclusion criteria included IC was due to obstructing cancer, follow up was not performed due to non-attendance at clinic or investigation and incomplete data set. Electronic notes were analysed to determine patient’s final clinical outcome. All patients were followed up for minimum of six months. Results Of the 8,490 colonoscopies, 733 (8.6%) were IC. 86 (11.7%) were excluded. Of the 647 included, 469 (72.4%) were females and 473 (73.1%) has further colonic investigations. Secondary investigations were: CT colonography 169 (35.7%), repeat colonoscopy 161 (34.0%), barium enema 95 (20.1%) and others 48 (10.1%). The repeat colonoscopy group achieved a complete colonoscopy in 111 (68.9%) patients. For those who had further investigations 15 (3.2%) had colorectal cancer and 12 (2.5%) has polyps ≥1cm. Conclusions There is significant risk of missing colorectal malignancy and large polyps following IC. Further colonic investigations should be carried out in this cohort of patients.

A122 WATER EXCHANGE FACILITATES HIGH CECAL INTUBATION RATE FOLLOWING INCOMPLETE COLONOSCOPY

Background Incomplete colonoscopy is a complex problem that negatively affects the success of colon cancer screening programs. Failure to intubate the cecum is associated with a significant risk of missed colorectal cancer and increases costs through missed diagnoses and salvage investigations. Water exchange (WE) colonoscopy is associated with a high rate of patient comfort and cecal intubation (CI) and may be of value in preventing and following up on incomplete colonoscopy. Aims To estimate effectiveness of WE colonoscopy as initial salvage of incomplete colonoscopy. Methods All patients referred to the Kelowna Gastroenterology group for incomplete colonoscopy between Jan 2010 to Dec 2019 were included. Demographic, clinical, procedural, and pathological information were collected via retrospective chart review. Patients underwent WE colonoscopy by a single endoscopist. The outcomes evaluated were CI rate, sedation requirements, and adenoma detection. Results 116 patients met study criteria and underwent WE colonoscopy after a previously failed or incomplete colonoscopy for technical reasons. The mean age was 66 years (range 21–89). 83 (72%) patients were female. 53 (46%) patients had previous abdominal surgery, and 42 (36%) had previous pelvic surgery. 65 (56%) patients had previous bowel disease. 81 (70%) patients had previously incomplete conventional air insufflation (AI) colonoscopy, 9 (8%) patients had previously incomplete WE colonoscopy, and 5 (4%) patients underwent unsuccessful combination of WE and AI colonoscopy. 17 (15%) patients had previously incomplete flexible sigmoidoscopy, and 4 (3%) patients had previously incomplete water immersion colonoscopy. The most common cause of unsuccessful CI was redundant colon (n=39, 34%) followed by strictures/angulations (n=16, 14%). 105 (91%) patients underwent repeat WE colonoscopy only, while 7 (6%) patients had combination WE and AI colonoscopy and 4 (3%) patients had concurrent gastroscopy. CI was successful in 114 (98%) patients and unsuccessful in 2 (2%) patients. 87 (75%) study patients received conscious sedation, 16 (14%) opted for no sedation, and 7 (6%) attempted no sedation then switched to conscious sedation. 5 patients (4%) required general anesthesia. CI was achieved in all 16 unsedated patients. 236 polyps were identified in 79 (68%) patients, 2 (1%) of which were malignant. Conclusions There is no standardized approach to incomplete colonoscopy. In this cohort of patients with previous failed attempt at colonoscopy, WE as a primary technique was associated with a high success rate with minimal need for general anesthesia and a high rate of polyp detection. A significant rate of colon cancer was identified, similar to that seen in general screening populations. Funding Agencies None

Collaboration between an NHS University Teaching Hospital and independent hospital to maintain CT colonography service provision during the 2020 COVID-19 pandemic

Our trust performed CTCs at 93% of the capacity of the previous year, scanning 1265 patients in 2020, compared with 1348 in 2019. We describe the changes made to our service to achieve this, which included collaboration with the colorectal surgical team to prioritise existing CTC patients according to faecal-immunochemical tests and full blood count results, and the associated challenges which included image transfer delays and patient attendance for scans. Furthermore, the endoscopy and radiology services used the opportunity created by co-location at the same hospital site to provide a same day incomplete colonoscopy and staging service for optically confirmed cancers. Collaboration between the NHS and independent sector allowed us to achieve continuity of service provision during the height of the COVID-19 pandemic without substituting unprepared CT abdomen and pelvis instead of the more sensitive CTC.

Colon Capsule Endoscopy vs. CT Colonography Following Incomplete Colonoscopy: A Systematic Review with Meta-Analysis

Following incomplete colonoscopy (IC) patients often undergo computed tomography colonography (CTC), but colon capsule endoscopy (CCE) may be an alternative. We compared the completion rate, sensitivity and diagnostic yield for polyp detection from CCE and CTC following IC. A systematic literature search resulted in twenty-six studies. Extracted data included inter alia, complete/incomplete investigations and polyp findings. Pooled estimates of completion rates of CCE and CTC and complete colonic view rates (CCE reaching the most proximal point of IC) of CCE were calculated. Per patient diagnostic yields of CCE and CTC were calculated stratified by polyp sizes. CCE completion rate and complete colonic view rate were 76% (CI 95% 68–84%) and 90% (CI 95% 83–95%). CTC completion rate was 98% (CI 95% 96–100%). Diagnostic yields of CTC and CCE were 10% (CI 95% 7–15%) and 37% (CI 95% 30–43%) for any size, 13% (CI 95% 9–18%) and 21% (CI 95% 12–32%) for >5-mm and 4% (CI 95% 2–7%) and 9% (CI 95% 3–17%) for >9-mm polyps. No study performed a reference standard follow-up after CCE/CTC in individuals without findings, rendering sensitivity calculations unfeasible. The increased diagnostic yield of CCE could outweigh its slightly lower complete colonic view rate compared to the superior CTC completion rate. Hence, CCE following IC appears feasible for an introduction to clinical practice. Therefore, randomized studies investigating CCE and/or CTC following incomplete colonoscopy with a golden standard reference for the entire population enabling estimates for sensitivity and specificity are needed.