Risk factors for severe complications of colonoscopy in screening programs

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.

Interval Cancer in Population-Based Colorectal Screening Programmes: Incidence and Characteristics of Tumours

The objective of this study is to evaluate interval cancer (IC) in colorectal cancer (CRC) screening, which is CRC diagnosed in an individual after having received a negative faecal occult blood test and before the next invitation to participate in screening. A follow-up study was conducted on a cohort of participants in the first three screening rounds of four colorectal cancer screening programmes in Spain, n = 664,993. A total of 321 ICs and 2120 screen-detected cancers (SCs) were found. The IC and SC rates were calculated for each guaiac (gFOBT) or immunochemical (FIT) test. A Cox regression model was used to estimate the hazard ratios (HR) of IC risk factors. A nested case-control study was carried out to compare IC and SC tumour characteristics. The IC rate was 1.16‱ with the gFOBT and 0.35‱ with the FIT. Men and people aged 60-69 showed an increased probability of IC (HR = 1.81 and HR = 1.95, respectively). There was a decreased probability of IC in individuals who regularly participated in screening, HR = 0.62 (0.47-0.82). IC risk gradually rose as the amount of Hb detected in the FIT increased. IC tumours were in more advanced stages and of a larger size than SC tumours, and they were mostly located in the cecum. These results may play a key role in future strategies for screening programmes, reducing IC incidence.

Colonoscopy: Preparation and Potential Complications

Colonoscopy is a fairly common test that serves both diagnostic and therapeutic purposes. It has been considered the gold standard in colorectal cancer screening for several years. Due to the nature of the examination, various types of complications may occur. The purpose of this analysis is to describe the various complications related to the period of preparation for colonoscopy among hospitalized patients, including life-threatening ones, in order to know how to avoid complications while preparing for a colonoscopy. We analyzed the nursing and medical reports of 9962 patients who were prepared for colonoscopy between 2005 and 2016. The frequency of various side effects associated with intensive bowel cleansing prior to colonoscopy was assessed. In justified cases, additional medical data were collected from patients, their families or from other doctors providing advice to patients after complications. Out of 9962 patients prepared for colonoscopy, 180 procedures were discontinued due to complications and side effects, and in these cases no colonoscopy was performed. The most common complications were: vomiting; epistaxis; loss of consciousness with head injury; abdominal pain; acute diarrhea; symptoms of choking; heart rhythm disturbances; dyspnea; fractures of limbs and hands; acute coronary syndrome; hypotension; hypertension; cerebral ischemia; severe blood glucose fluctuations; increased muscle contraction and allergic reactions. In addition to the documentation of our own research, several works of other research groups were also analyzed. Currently, the literature does not provide data on the frequency and type of complications in the preparation period for colonoscopy. The advantage of our work is the awareness of the possibility of serious complications and postulating the necessary identification of threats. Individualization of the recommended procedures and increased supervision of patients undergoing bowel cleansing procedure, we hope, will reduce the occurrence of complications and side effects.

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

INTRODUCTION

Colorectal cancer (CRC) screening programs based on the fecal immunochemical test (FIT) and guaiac-based fecal occult blood (gFOBT) are associated with a substantial reduction in CRC incidence and mortality. We conducted a systematic review and comprehensive meta-analysis to evaluate colonoscopy-related adverse events in individuals with a positive FIT or gFOBT.

METHODS

A systematic and detailed search was run in January 2021, with the assistance of a medical librarian for studies reporting on colonoscopy-related adverse events as part of organized CRC screening programs. Meta-analysis was performed using the random-effects model, and the results were expressed for pooled proportions along with relevant 95% confidence intervals (CIs).

RESULTS

A total of 771,730 colonoscopies were performed in patients undergoing CRC screening using either gFOBT or FIT across 31 studies. The overall pooled incidence of severe adverse events in the entire patient cohort was 0.42% (CI 0.20-0.64); I2 = 38.76%. In patients with abnormal gFOBT, the incidence was 0.2% (CI 0.1-0.3); I2 = 24.6%, and in patients with a positive FIT, it was 0.4% (CI 0.2-0.7); I2 = 48.89%. The overall pooled incidence of perforation, bleeding, and death was 0.13% (CI 0.09-0.21); I2 = 22.84%, 0.3% (CI 0.2-0.4); I2 = 35.58%, and 0.01% (CI 0.00-0.01); I2 = 33.21%, respectively.

DISCUSSION

Our analysis shows that in colonoscopies performed after abnormal stool-based testing, the overall risk of severe adverse events, perforation, bleeding, and death is minimal.

Alterations in the Gut Microbiota and Their Metabolites in Colorectal Cancer: Recent Progress and Future Prospects

Colorectal cancer (CRC) is a leading cause of cancer morbidity and mortality worldwide. The etiology and pathogenesis of CRC remain unclear. A growing body of evidence suggests dysbiosis of gut bacteria can contribute to the occurrence and development of CRC by generating harmful metabolites and changing host physiological processes. Metabolomics, a systems biology method, will systematically study the changes in metabolites in the physiological processes of the body, eventually playing a significant role in the detection of metabolic biomarkers and improving disease diagnosis and treatment. Metabolomics, in particular, has been highly beneficial in tracking microbially derived metabolites, which has substantially advanced our comprehension of host-microbiota metabolic interactions in CRC. This paper has briefly compiled recent research progress of the alterations of intestinal flora and its metabolites associated with CRC and the application of association analysis of metabolomics and gut microbiome in the diagnosis, prevention, and treatment of CRC; furthermore, we discuss the prospects for the problems and development direction of this association analysis in the study of CRC. Gut microbiota and their metabolites influence the progression and causation of CRC, and the association analysis of metabolomics and gut microbiome will provide novel strategies for the prevention, diagnosis, and therapy of CRC.

Facilitators and barriers to participation in population-based colorectal cancer screening programme from the perspective of healthcare professionals: Qualitative research study

OBJECTIVE

High participation determines the success of colorectal cancer screening programmes in reducing incidence and mortality. The factors that determine participation must be studied from the perspective of professionals that implement the programme. The aim was to identify factors that facilitate or hinder the participation of the invited people in the bowel cancer screening programme of the Basque Country (Spain) from professional's perspective.

METHODS

Qualitative design based on individual interviews and focus groups. Thirty-eight primary care professionals who implement the programme participated (administrative staff, nurses and general practitioners). Thematic analysis was performed.

RESULTS

Professionals show high satisfaction with the programme, and they believe firmly in its benefits. Facilitators for participation include professionals' commitment to the programme, their previous positive experiences, their optimistic attitude towards the prognosis of cancer and their trust in the health system and accessibility. Barriers include invitees' lack of independence to make decisions, fear of a positive test result and patient vulnerability and labour mobility of the health professionals.

CONCLUSIONS

Professionals show a high degree of involvement and identify primary care is an appropriate place to carry out disease prevention. They identify the closeness to patients, the personal attitude and the characteristics of the health system as key factors that influence participation.

Colonoscopy-Related Mortality in a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program

BACKGROUND & AIMS

Many countries have introduced colorectal cancer (CRC) screening programs with fecal immunochemical tests (FITs), and follow-up colonoscopies for individuals with a positive FIT result. In order to make an informed decision to participate, individuals must be informed about the benefits and harms of FIT-based screening and subsequent colonoscopy. Colonoscopy-related fatal complications in FIT-based screening are understudied. We aimed to estimate the colonoscopy-related mortality in a national FIT-based CRC screening program.

METHODS

Colonoscopy-related mortality within 30 days after colonoscopy was assessed by analysis of data from national endoscopy complication databases in the Netherlands, determining the excess 30-day rate of death in FIT-positive individuals undergoing colonoscopy vs FIT-negative individuals (based on data from the national screening database), and determining the rate of likely colonoscopy-related deaths based on registered causes of death by the Statistics Netherlands.

RESULTS

Between October 2013 and December 2017, 172,797 participants underwent colonoscopy after a positive result from a FIT in the Dutch national CRC screening program; 13,848 participants received a diagnosis of CRC. The reported fatal complication rate was 0.23 per 10,000 FIT-positive participants (or 1 per 43,199; 95% CI, 0.090 - 0.60) undergoing colonoscopy, whereas this was 0.91 per 10,000 FIT-positive participants (or 1 per 10,961; 95% CI, 0.44 - 1.38) according to the excess death rate. Likely colonoscopy-related causes of death were reported in 0.86 per 10,000 FIT-positive participants (or 1 per 11,236; 95% CI, 0.48 - 1.63) who underwent colonoscopy, of which 50% considered cardiovascular events.

CONCLUSIONS

Colonoscopy-related mortality within the Dutch FIT-based CRC screening program was estimated to range from 0.23 to 0.91 per 10,000 FIT-positive participants undergoing colonoscopy. These findings indicate underreporting of fatal complications in registries and a noteworthy incidence of fatal cardiovascular adverse events that requires further investigation. Nevertheless, the harm of FIT-based CRC screening is vastly outweighed by the benefits.

Protective Effects of Bariatric Surgery on Kidney Functions by Inhibiting Oxidative Stress Responses Through Activating PPARα in Rats With Diabetes

Objective

The aim of this study was to explore the protective effects and the regulatory mechanisms of bariatric surgery on kidney injury in diabetic rats.

Methods

We established a useful type 2 diabetic rat model using high-fat and high-sugar diet feeding following low-dose streptozotocin (STZ) treatment. Sprague–Dawley (SD) rats were randomly divided into the following groups: control (Con) group, diabetic nephropathy (DN) group, and duodenal–jejunal bypass (DJB) surgery group. The food intake and body weight of rats were monitored and the glucose tolerance test (OGTT) test was performed every 2 weeks. The glomerular filtration rate (GFR) and urinary albumin excretion rate (UAFR) were measured to assess renal function. Hematoxylin–eosin (H&E), periodic acid–Schiff (PAS), and Masson staining were used to evaluate renal histopathological changes. TUNEL assay was performed to detect cell apoptosis. The expressions of oxidative stress factors and inflammatory factors in the renal tissues of rats were detected by ELISA. The expressions of PPARα, reactive oxygen species (ROS), and NF-κB were detected by immunofluorescence. For in vitro experiment, HK2 cells cultured with high glucose were treated with PPARα agonist, PPARα antagonist, and adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK) agonist. The expressions of AMPK/PPARα/NF-κB signaling pathway-related proteins were detected by Western blot.

Results

Bariatric surgery improved the glucose tolerance of DN rats. The GFR was decreased, the promotion of urinary albumin excretion rate (UAER) was inhibited, and the renal injury was alleviated. The extracellular matrix fraction was decreased and the renal function was improved. Meanwhile, bariatric surgery activates PPARα, inhibits ROS release, reduces oxidative stress injury, and reduces renal cell apoptosis. In vitro experiment results showed that the AMPK activator could activate PPARα, downregulate NF-κB, and inhibit inflammatory response. The phosphorylation of AMPK was inhibited by PPARα antagonism.

Conclusion

Bariatric surgery can activate PPARα, inhibit oxidative stress injury, and improve glucose metabolism and renal function in DN rats.