Colonoscopy-Related Adverse Events in Patients With Abnormal Stool-Based Tests: A Systematic Review of Literature and Meta-analysis of Outcomes

Adverse events after colonoscopy in a randomised colorectal cancer screening trial

OBJECTIVE

Colonoscopy-related adverse events increase the burden of colorectal cancer (CRC) screening. This cross-sectional study evaluates adverse events during and after colonoscopy in a large, randomised CRC screening trial in Norway comparing sigmoidoscopy to immunochemical testing for faecal blood.

METHODS

We included all individuals who underwent colonoscopy at two screening centres between 2012 and 2020. From medical records, we retrieved data on adverse events during and within 30 days after colonoscopy and classified them according to the American Society for Gastrointestinal Endoscopy lexicon for endoscopic adverse events. Multivariable logistic regression models were fitted to identify risk factors for adverse events.

RESULTS

Of the 10 244 included individuals, 242 (2.4%) had at least one adverse event that was possibly, probably, or definitively related to the colonoscopy. 188 (1.8%) had mild adverse events, 50 (0.49%) had moderate, 3 (0.03%) had severe, and 1 had a fatal adverse event. The most frequent adverse events were lower gastrointestinal bleeding (0.86%), abdominal pain (0.48%), vasovagal reaction (0.39%), postpolypectomy syndrome (0.20%), and perforation (0.08%). 23 (0.22%) individuals had non-gastrointestinal adverse events. Risk factors associated with adverse events were older age, female sex, screening centre, anticoagulant therapy, number of polypectomies, size of lesion removed, presence of proximal lesion, and adenocarcinoma. Adverse event rates per endoscopist ranged from 0% to 4.9%.

CONCLUSION

Adverse events after colonoscopy of screening positives occurred in about 2 out of 100 procedures. Three-quarters of events were mild. Awareness of risk factors may help endoscopists to mitigate the risk.

TRIAL REGISTRATION NUMBER

NCT01538550.

Periprocedural Anticoagulation Management of Patients Undergoing Colonoscopy with Polypectomy

Introduction/Objective  Colonoscopy with polypectomy is an integral component of colorectal cancer screening. There are limited data and consensus on periprocedural anticoagulation management, especially regarding bleeding risk with uninterrupted anticoagulation and thromboembolic risk with interruption. Our aim was to determine the incidence of bleeding and thromboembolic complications among colon screening participants undergoing colonoscopy following implementation of a novel patient care pathway for standardized periprocedural anticoagulation management. Methods  We conducted a retrospective study including all participants (age 50-74) on an oral anticoagulant (e.g., vitamin K antagonists, direct oral anticoagulants) referred to the British Columbia Colon Screening Program for colonoscopy following abnormal fecal immunochemical test in a 6-month period (March-August 2022). Data relating to their specific periprocedural anticoagulant management and colonoscopy results including method of polypectomy were obtained. Primary outcomes were major bleeding and arterial or venous thromboembolic events from time of oral anticoagulant interruption until 14 days of postcolonoscopy. Secondary outcomes included nonmajor and minor bleeding, acute coronary syndrome, emergency room visit, hospital admission, and death due to any cause. Results  Over the 6-month period, 162 participants completed standardized periprocedural anticoagulation management, colonoscopy ± polypectomy, and 14-day follow-up. One (0.6%) had a major bleeding event and one (0.6%) had an arterial thromboembolic event. Conclusions  A novel patient care pathway for standardized periprocedural anticoagulation management with a multidisciplinary team is associated with low rates of major bleeding and thrombotic complications after colonoscopy with polypectomy.

The value of hypersensitivity quantitative fecal immunochemical test in early colorectal cancer detection

At present, both the incidence and mortality rates of colorectal cancer are on the rise, making early screening a crucial tool in reducing the fatality rate. Although colonoscopy is the recommended method according to the guidelines, compliance tends to be poor. The fecal immunochemical test (FIT), a new technology that uses latex immunoturbidimetry to detect fecal blood, offers high specificity and sensitivity. Additionally, it is low-cost, easy to operate, and less likely to be affected by food and drugs, thus improving the compliance rate for population screening. Compared to other screening techniques, FIT represents a safer and more accurate option. This article reviews the application of FIT in early colorectal cancer screening.

Faecal haemoglobin concentration in adenoma, before and after polypectomy, approaches the ideal tumour marker

BACKGROUND

Polypectomy may be performed at colonoscopy and then subsequent surveillance undertaken. It is thought that faecal haemoglobin concentration (f-Hb), estimated by quantitative faecal immunochemical tests (FIT), might be a useful tumour marker.

METHODS

Consecutive patients enrolled in colonoscopy surveillance were approached at two hospitals. A specimen for FIT was provided before colonoscopy and, ideally after 3 weeks, a second FIT sample from those who had polypectomy. A single FIT system (OC-Sensor io, Eiken Chemical Co., Ltd) was used to generate f-Hb.

RESULTS

1103 Patients were invited; 643 returned a FIT device (uptake: 58.3%). Four patients had known inflammatory bowel disease (IBD) and were excluded, leaving 639 (57.9%) with an age range of 25-90 years (median 64 years), 54.6% male. Of 593 patients who had a f-Hb result and completed colonoscopy, advanced neoplasia was found in 41 (6.9%); four colorectal cancer (CRC): 0.7% and 37 advanced adenoma (AA): 6.3%, and a further 127 (21.4%) had non-advanced adenoma (NAA). The median f-Hb was significantly greater in AA as compared to NAA; 6.0 versus 1.0 μg Hb/g faeces, p < 0.0001.134/164 (81.7%) of invited patients returned a second FIT device: 28 were patients with AA in whom median pre-polypectomy f-Hb was 19.2, falling to 3.5 μg Hb/g faeces post-polypectomy, p = 0.01, and 106 with NAA had median pre-polypectomy f-Hb 0.8 compared to 1.0 μg Hb/g faeces post-polypectomy, p = 0.96.

CONCLUSIONS

Quantitative FIT could provide a good tumour marker in post-polypectomy surveillance, reduce colonoscopy requirements and minimise potential risk to patients.

Comparison with first round findings of faecal haemoglobin concentrations and clinical outcomes in the second round of a biennial faecal immunochemical test based colorectal cancer screening programme

Objective

How faecal haemoglobin concentrations (f-Hb) vary from one round to the next in a colorectal cancer (CRC) screening programme, and relate to colonoscopy findings, are unknown. Our aim was to use data from the first two rounds of the faecal immunochemical test (FIT) based Scottish Bowel Screening Programme (SBoSP) to explore these issues.

Methods

Faecal haemoglobin concentration (f-Hb) percentiles in the second round were compared with those in the first when the first round yielded a negative FIT result (<80 µg Hb/g faeces), a positive FIT but no colonoscopy, CRC, all adenoma, and a negative colonoscopy. In addition, the outcomes in the first and second rounds were compared.

Results

The profiles of f-Hb in the first and second rounds differed in (a) those who had had a negative FIT result in the first round and (b) those in whom neoplastic pathology had been found. In contrast, the pattern of difference between profiles in those who had had a negative colonoscopy was very similar to that in those in whom an adenoma had been found. In addition, the risk of CRC being diagnosed in the second round after a negative colonoscopy in the first was 3.0%, not very different to that after a negative test result (4.9%).

Conclusions

Adenomas may be rarely the cause of a positive FIT result. An alternative explanation as to why these are detected using FIT is required. In addition, a negative colonoscopy for a positive FIT result does not rule out the finding of significant neoplastic pathology in the next round.