Risk of colon perforation during colonoscopy at Baylor University Medical Center

Endoscopic surgery robot that facilitates insertion of the curved colon and ensures positional stability against external forces: K-COLON

BACKGROUND

Although various endoscopic surgery robots developed in previous studies are versatile and have high lesion accessibility, they have limitations in terms of reaching the target lesion through the curved path in the large intestine and providing a stable tasking environment for the operator.

METHODS

An endoscopic surgery robot was developed for performing surgery in the large intestine. The robot was easily inserted into the target lesion in the curved colon through the mounted soft actuator and demonstrated high structural stiffness through the insertion of the sigmoidal auxiliary tendons.

RESULTS

The robot was able to access the target lesion in the curved colon through teleoperation alone. Further, it was confirmed that the high structural stiffness overtube improved the overall task performance in the user test.

CONCLUSIONS

The proposed robotic system demonstrated the possibility and potential of performing advanced endoscopic surgery in the large intestine.

Colonoscopy Complications in an Iranian Teaching Hospital

BACKGROUND: Colonoscopy is generally a safe procedure with a limited number of adverse events. Few studies have addressed the rate of adverse events in teaching hospitals. This study aimed to investigate the rate of complications after colonoscopy performed by gastroenterology fellows in a teaching hospital in Tehran. METHODS: A historical cohort study was carried out to link the colonoscopy reports and the hospital information system to identify serious adverse events leading to unplanned hospitalization, unplanned procedures or interventions (e.g. surgery), prolongation of existing hospitalization, or death within 30 days after colonoscopy. RESULTS: We included 9928 colonoscopies (mean age of the patients 53.0±15.9 years, 52.3% men) in this study. In-hospital patients comprised (34.8%) of the procedures. The indications of colonoscopy included 7137 diagnostic (71.9%), and 2519 screening (25.4%) reasons. Colorectal polyps were found in 2005 (20.2%) patients. Major complications were seen in 17 patients (0.2%), including serious bleeding in seven patients, cardiopulmonary complications in five patients, perforation in four patients, and sepsis in one patient. CONCLUSION: Serious adverse events after colonoscopy are relatively rare. The rate of complications does not appear to be higher in an academic teaching hospital when performed by fellows under supervision.

Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in the US.

OBJECTIVE

To systematically review the effectiveness, test accuracy, and harms of screening for CRC to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant studies published from January 1, 2015, to December 4, 2019; surveillance through March 26, 2021.

STUDY SELECTION

English-language studies conducted in asymptomatic populations at general risk of CRC.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently appraised the articles and extracted relevant study data from fair- or good-quality studies. Random-effects meta-analyses were conducted.

MAIN OUTCOMES AND MEASURES

Colorectal cancer incidence and mortality, test accuracy in detecting cancers or adenomas, and serious adverse events.

RESULTS

The review included 33 studies (n = 10 776 276) on the effectiveness of screening, 59 (n = 3 491 045) on the test performance of screening tests, and 131 (n = 26 987 366) on the harms of screening. In randomized clinical trials (4 trials, n = 458 002), intention to screen with 1- or 2-time flexible sigmoidoscopy vs no screening was associated with a decrease in CRC-specific mortality (incidence rate ratio, 0.74 [95% CI, 0.68-0.80]). Annual or biennial guaiac fecal occult blood test (gFOBT) vs no screening (5 trials, n = 419 966) was associated with a reduction of CRC-specific mortality after 2 to 9 rounds of screening (relative risk at 19.5 years, 0.91 [95% CI, 0.84-0.98]; relative risk at 30 years, 0.78 [95% CI, 0.65-0.93]). In observational studies, receipt of screening colonoscopy (2 studies, n = 436 927) or fecal immunochemical test (FIT) (1 study, n = 5.4 million) vs no screening was associated with lower risk of CRC incidence or mortality. Nine studies (n = 6497) evaluated the test accuracy of screening computed tomography (CT) colonography, 4 of which also reported the test accuracy of colonoscopy; pooled sensitivity to detect adenomas 6 mm or larger was similar between CT colonography with bowel prep (0.86) and colonoscopy (0.89). In pooled values, commonly evaluated FITs (14 studies, n = 45 403) (sensitivity, 0.74; specificity, 0.94) and stool DNA with FIT (4 studies, n = 12 424) (sensitivity, 0.93; specificity, 0.85) performed better than high-sensitivity gFOBT (2 studies, n = 3503) (sensitivity, 0.50-0.75; specificity, 0.96-0.98) to detect cancers. Serious harms of screening colonoscopy included perforations (3.1/10 000 procedures) and major bleeding (14.6/10 000 procedures). CT colonography may have harms resulting from low-dose ionizing radiation. It is unclear if detection of extracolonic findings on CT colonography is a net benefit or harm.

CONCLUSIONS AND RELEVANCE

There are several options to screen for colorectal cancer, each with a different level of evidence demonstrating its ability to reduce cancer mortality, its ability to detect cancer or precursor lesions, and its risk of harms.

Assessing Histological Inflammatory Activity in Patients With Ulcerative Colitis: A Diagnostic Accuracy Study Testing Fecal Biomarkers Lactoferrin and Calprotectin

Background and Aims

Histological remission has arisen as the optimal treatment outcome in ulcerative colitis (UC). The aim of this retrospective study was to explore the diagnostic performance of the noninvasive fecal biomarkers calprotectin (FC) and lactoferrin (FL) compared to the histological indices Nancy Index (NI) and Riley Index (RI).

Methods

This study is a retrospective diagnostic accuracy study based on secondary analysis of patient data from 2002 to 2017 extracted from medical registries of our clinics in Essen-Mitte, Germany. Patients with UC underwent a colonoscopy, with biopsies taken from the rectum and the sigmoid scored by 2 experienced pathologists according to NI and RI and provided a stool sample within 7 days pre- or post-colonoscopy. Diagnostic accuracy of recommended cutoffs for FC (>50 μg/g) and FL (≥7.25 μg/g) were tested against our reference standard (NI ≥2) in terms of specificity, sensitivity, positive predictive value, negative predictive value, and accuracy (effectiveness).

Results

The number of patients with UC recruited was n = 226, aged 45.2 (SD 13.3). Histological indices were highly correlated (r = 0.980, P < 0.001). Fecal biomarkers correlated moderately with NI (FC: r = 0.383, P < 0.001; FL: r = 0.420, P < 0.001) and RI (FC: r = 0.395, P < 0.001; FL: r = 0.424, P < 0.001). Fecal biomarker concentrations were increased in patients with active histological disease (NI ≥2), median [IQR], FC 69.72 [20.07-254.38], FL 18.59 [6.06-44.42], compared to those with inactive disease (NI ≤1), FC 12.35 [3.89 - 32.16], FL 3.14 [0.75-11.05], z = -6.60, P < 0.001. Fecal biomarker concentrations differed significantly across NI grades 0-4 (FC: H₄ = 45.2; FL: H₄ = 47.5, both P < 0.001). Patients with grade 0 had significantly lower concentrations of fecal biomarkers than those with grade 3 (median; FC 10.94 vs 72.22; FL 2.30 vs 29.10; both P < 0.001) or grade 4 (FC 10.94 vs 67.00; FL 2.30 vs 27.64; both P < 0.001), as well as grade 2 for FC only (10.94 vs 56.22, P = 0.001). Concentrations were also lower in patients with grade 1 compared to those with grade 3 (FC 17.49 vs 72.22; FL 4.24 vs. 29.10; both P ≤ 0.001) or grade 4 (FC 17.49 vs 67.00; FL 4.24 vs 27.64; both P < 0.001).Receiver operating characteristics area under the curve showed moderate diagnostic accuracy for both FC 0.76 (95% confidence interval [CI] 0.70-0.83) and FL 0.73 (95% CI 0.66-0.80). Optimized cutoffs for both FC (≥34.29) and FL (≥5.85 μg/g) had slightly improved accuracy, compared with the manufacturer's cutoffs (FC: 69.9% vs 65.9%; FL: 71.7% vs 69.0%).

Conclusions

Fecal biomarkers calprotectin and lactoferrin correlate with histological disease activity and differentiate between patients in histological remission from those with evidence of moderate to severe disease activity. Their noninvasiveness, in addition to being inexpensive, supports their use in the clinical monitoring of patients with UC.

Muscularis propria detected at colonic biopsy is not a critical value

Perforation is a rare but potentially serious complication of cold forceps colonic biopsies. The presence of muscularis propria might portend increased risk of perforation and warrant urgent communication with endoscopists. However, identifying muscularis propria at time of biopsy is difficult for many reasons, including histologic overlap with muscularis mucosa. Incidental muscularis propria obtained in this manner has yet to be studied. Our objectives were to characterize the morphology of muscularis propria obtained incidentally via cold forceps colonic biopsies, establish practical criteria for diagnosing muscularis propria, and determine whether diagnosing muscularis propria correlates with perforation clinically. We retrospectively reviewed 3 specimens from nontargeted cold forceps colonic biopsies for which pieces of muscularis propria were presumed to be visualized based on larger size or lower nuclear density compared to the corresponding muscularis mucosa. These specimens were then compared to normal transmural control tissue from colectomy to confirm whether nuclear density or other features could distinguish muscularis propria from muscularis mucosa. Muscularis propria in the control tissue had lower nuclear density, smoother cytoplasmic texture, and more cytoplasmic pallor compared to the muscularis mucosa in the control tissue. This constellation of features was seen in all 3 specimens obtained via biopsy and therefore confirmed the presence of muscularis propria, though all patients lacked perforation clinically. Large size, low nuclear density, smooth cytoplasm, and pale cytoplasm identify objects as muscularis propria at time of colonic biopsy. The presence of muscularis propria fails to correlate with perforation clinically and does not warrant urgent communication.

The Impact of Hospital Teaching Status on Colonoscopy Perforation Risk: A National Inpatient Sample Study

Background

Colonoscopy has been widely used as a diagnostic tool for many conditions, including inflammatory bowel disease and colorectal cancer. Colonoscopy complications include perforation, hemorrhage, abdominal pain, as well as anesthesia risk. Although rare, perforation is the most dangerous complication that occurs in the immediate post-colonoscopy period with an estimated risk of less than 0.1%. Studies on colonoscopy perforation risk between teaching hospitals and non-teaching hospitals are scarce.

Methods

The National Inpatient Sample database was queried for patients who underwent inpatient colonoscopy between January 2010 and December 2014 in teaching versus non-teaching facilities in order to study their perforation rates. Our study population included 257,006 patients. Univariate regression was performed, and the positive results were analyzed using a multivariate regression module.

Results

Teaching hospitals had a higher risk of perforation (odds ratio 1.23, confidence interval 1.07 - 1.42, P = 0.004). Perforation rates were higher in females, patients with inflammatory bowel disease and dilatation of strictures. Polypectomy did not yield any statistical difference between the study groups. Other factors such as African-American ethnicity appeared to have a lower risk.

Conclusion

Perforation rates are higher in teaching hospitals. More studies are needed to examine the difference and how to mitigate the risks.

A Soft Pneumatic Inchworm Double balloon (SPID) for colonoscopy

The design of a smart robot for colonoscopy is challenging because of the limited available space, slippery internal surfaces, and tortuous 3D shape of the human colon. Locomotion forces applied by an endoscopic robot may damage the colonic wall and/or cause pain and discomfort to patients. This study reports a Soft Pneumatic Inchworm Double balloon (SPID) mini-robot for colonoscopy consisting of two balloons connected by a 3 degrees of freedom soft pneumatic actuator. SPID has an external diameter of 18 mm, a total length of 60 mm, and weighs 10 g. The balloons provide anchorage into the colonic wall for a bio-inspired inchworm locomotion. The proposed design reduces the pressure applied to the colonic wall and consequently pain and discomfort during the procedure. The mini-robot has been tested in a deformable plastic colon phantom of similar shape and dimensions to the human anatomy, exhibiting efficient locomotion by its ability to deform and negotiate flexures and bends. The mini-robot is made of elastomer and constructed from 3D printed components, hence with low production costs essential for a disposable device.

Ischaemic colitis: uncertainty in diagnosis, pathophysiology and management

Ischaemic colitis is the most common form of gastrointestinal ischaemia, but may be confused with acute mesenteric ischaemia, inflammatory bowel disease or infectious colitis. This review article outlines the current classification, epidemiology and risk factors, as well as approaches about diagnosis and management to guide clinical practice. It also identifies areas for further research.

DNA methylation patterns as noninvasive biomarkers and targets of epigenetic therapies in colorectal cancer

Aberrant DNA methylation is frequently detected in gastrointestinal tumors, and can therefore potentially be used to screen, diagnose, prognosticate, and predict colorectal cancers (CRCs). Although colonoscopic screening remains the gold standard for CRC screening, this procedure is invasive, expensive, and suffers from poor patient compliance. Methylated DNA is an attractive choice for a biomarker substrate because CRCs harbor hundreds of aberrantly methylated genes. Furthermore, abundance in extracellular environments and resistance to degradation and enrichment in serum, stool, and other noninvasive bodily fluids, allows quantitative measurements of methylated DNA biomarkers. This article describes the most important studies that investigated the efficacy of serum- or stool-derived methylated DNA as population-based screening biomarkers in CRC, details several mechanisms and factors that control DNA methylation, describes a better use of prevailing technologies that discover novel DNA methylation biomarkers, and illustrates the diversity of demethylating agents and their applicability toward clinical impact.

Colonoscopic Perforations, What is Our Experience in a Training Hospital?

The aim of this study was to describe our experience in patients treated with the diagnosis of colonoscopic perforation. A retrospective institutional computer-based search of the patients treated with the diagnosis of colonoscopic perforation between July 2009 and May 2014 was undertaken. Our study included 16 patients. In 9 (56%) patients, perforations occurred during the diagnostic colonoscopy. Snare polypectomy was the causative factor in 5 patients associated with therapeutic colonoscopy. The perforation was significantly higher in patients who underwent therapeutic colonoscopy than those had diagnostic colonoscopy (P<0.007). The sigmoid colon was the most common perforation site (62.5%). Twelve patients (75%) were treated by surgically, 3 (19%) patients by conservatively, and 1 (6%) by endoscopic clipping. Early recognition of the perforation is critical. Therefore, a high index of suspicion is essential for the prompt and accurate diagnosis.