(Technically) Difficult colonoscope insertion - Tips and tricks

Magnetic endoscopic imaging in pediatric colonoscopy: A positive impact on procedure completion rate and procedure times

OBJECTIVES

To assess the impact of magnetic endoscopic imaging (MEI) on pediatric colonoscopy.

METHODS

We analyzed demographics, procedure completion, procedure times, complications, and whether or not MEI was used for all colonoscopies between April 27, 2023, and January 18, 2024. MEI was available for every case but used at the endoscopist's discretion. Attendings were surveyed on the frequency and duration of interventions during fellow-performed colonoscopies.

RESULTS

We analyzed 310 colonoscopies, 113 (36%) of which used MEI. The average patient age was 13.8 years (range 5 months to 23 years). For the aggregate sample and attending-performed cases, there were fewer males in the groups that used MEI (p < 0.01). There were no other statistically significant differences in demographics or procedure indication when MEI was used. Terminal ileum (TI) intubation rate was higher when MEI was used in the aggregate sample (p = 0.02) and for fellow-performed cases (p = 0.04). TI intubation times and total procedure times were quicker when MEI was used in the aggregate sample and in both strata of attending-performed cases and fellow-performed cases (p < 0.001). One complication was reported in an attending-performed case that did not use MEI. Of the 145 fellow-performed procedures, 98 (68%) had completed surveys, 36 (36%) of which used MEI. There was no statistically significant difference in the number (p = 0.89) or duration (p = 0.96) of attending interventions when MEI was used.

CONCLUSION

MEI use was associated with higher TI intubation rates, faster TI intubation, and shorter total procedure times. MEI may be a valuable adjunctive tool for pediatric endoscopists.

Strategies, Technologies, and Tips for Successful Cecal Intubation

Successful cecal intubation is crucial in ensuring a complete evaluation of the colonic mucosa. Although completion of colonoscopies should be successful in close to 100% of all examinations in the hands of experienced gastroenterologists, there are some patients with colons which can be difficult to navigate. Factors such as older age, presence of diverticular disease, as well as high or low body mass index can present challenges for endoscopists. Challenges can be divided into those that are left sided and are associated with severe angulations of the colon versus those that are right sided and present as redundant colons. Both require different strategies to achieve completion. This review will cover methods, technologies as well the evolution of colonoscope insertion tubes which can help in navigating colons, especially those that are challenging. There will also be a discussion about basic principles and techniques that should be employed in all colonoscopies.

Retrograde colon imaging through colonic transendoscopic enteral tubing helps to confirm the cause of difficult colonoscopy: a case report

Numerous factors can contribute to a difficult colonoscopy, potentially leading to an incomplete procedure and overlooked lesions. Alternative strategies for handling difficult and incomplete colonoscopies should be considered. We present the case of an 85-year-old male who underwent a difficult colonoscopy, during which two expert endoscopists spent 1.5 h attempting various techniques but failed to intubate the cecum. Subsequently, colonic transendoscopic enteral tubing (TET) was performed. Abdominal plain film revealed tortuosity of the TET tube in the left abdomen corresponding to the distribution of the descending colon. Retrograde colon imaging was conducted by injecting a mixture of contrast medium and air into the colon via the TET tube. X-ray demonstrated well-developed visualization of the entire colon and terminal ileum. And evident elongation and tortuosity of the descending colon resembled an N-type folding pattern. The final diagnosis was determined as descending colon redundancy. Colonic TET combined with retrograde colon imaging through the TET tube may serve as an effective supplementary approach for identifying causes of difficult colonoscopy and improving diagnostic accuracy for bowel diseases when complete visualization is not achieved.

Strategies to manage the difficult colonoscopy

During endoscopy, an endoscopist is inevitably faced with the occasional “difficult colonoscopy,” in which the endoscopist finds it challenging to advance the endoscope to the cecum. Beyond optimization of technique, with minimized looping, minimal insufflation, sufficient sedation, and abdominal splinting when needed, sometimes additional tools may be needed. In this review, we cover available techniques and technologies to help navigate the difficult colonoscopy, including the ultrathin colonoscope, rigidizing overtube, balloon-assisted colonoscopy and the abdominal compression device.

Atrophic gastritis rather than Helicobacter pylori infection can be an independent risk factor of colorectal polyps: a retrospective study in China

BACKGROUND

Colonoscopy is considered the most effective screening method for colorectal polyps. However, the longevity and complexity of the procedure makes it less desirable to screen for colorectal polyps in the general population. Therefore, it is essential to identify other independent risk factors. In this study, we explored the link between Hp infection, atrophic gastritis, and colorectal polyps to identify a new potential risk factors of colorectal polyps.

METHODS

In this study, atrophic gastritis and intestinal polyps were diagnosed by endoscopy and pathology. All the 792 patients in this retrospective study were divided into sub-groups based on the presence of colorectal polyps. The correlation between polyps and atrophic gastritis was analyzed using the chi-square test and Kruskal-Wallis test. The receiver operating characteristic (ROC) curve was used to compare the predictive value for colorectal polyps between Hp infection and atrophic gastritis. Binary logistic regression was utilized to identify independent risk factors for colorectal polyps.

RESULTS

Patients with colorectal polyps were primarily male with advanced age, and the number of patients with colorectal polyps had a higher association with smoking, alcohol drinking, and Hp infection than the control group. A positive correlation between the number of colorectal polyps and the severity of atrophic gastritis was observed. ROC analysis showed that atrophic gastritis was a better risk factors for colorectal polyps. Multivariate analysis identified atrophic gastritis as an independent risk factor for colorectal polyps (OR 2.294; 95% CI 1.597-3.296).

CONCLUSIONS

Atrophic gastritis confirmed could be an independent risk factors for colorectal polyps.

Existing Bowel Preparation Quality Scales Are Reliable in the Setting of Centralized Endoscopy Reading

BACKGROUND

Development of bowel preparation products has been based upon colon cleansing rating by a local endoscopist. It is unclear how bowel preparation scales perform when centrally evaluated.

AIMS

To evaluate the reliability of bowel preparation quality scales when assessed by central readers.

METHODS

Four central readers evaluated 52 videos in triplicate, 2 weeks apart, during the entire endoscopic procedure (insertion/withdrawal of the colonoscope) and exclusively on colonoscope withdrawal using the Boston Bowel Preparation Scale (BBPS), Chicago Bowel Preparation scale, Harefield Cleansing Scale, Ottawa Bowel Preparation Quality Scale (OBPQS), Aronchick score, a visual analogue scale, and additional items proposed in a modified Research and Development/University of California Los Angeles appropriateness process. Reliability was assessed with intraclass correlation coefficients.

RESULTS

Intraclass correlation coefficients (95% confidence interval) for inter-rater reliability of the quality scales ranged from 0.51 to 0.65 (consistent with moderate to substantial inter-rater reliability) during the entire procedure. Corresponding intraclass correlation coefficients for intra-rater reliability ranged from 0.69 to 0.77 (consistent with substantial intra-rater reliability). Reliability was highest in the right colon and lowest in the left colon. No differences were observed in reliability when assessed for the procedure overall (insertion/withdrawal) relative to assessment on withdrawal alone.

CONCLUSION

All five bowel preparation quality scales had moderate to substantial inter-rater reliability. Panelists considered the Aronchick score too simplistic for clinical trials and recognized that assessment of residual fluid in the Ottawa Bowel Preparation Quality Scale was not amenable to central assessment.

Impact of an Abdominal Compression Bandage on the Completion of Colonoscopy for Obese Adults: A Prospective Randomized Controlled Trial

METHODS

Eligible patients were randomly allocated into the abdominal bandage and conventional groups during a routine colonoscopy. The primary outcome was CCR.

RESULTS

A total of 250 eligible patients were randomly assigned to the abdominal bandage and conventional groups from January 2021 to April 2021. Eleven patients (five in the abdominal bandage group and six in the conventional group) were excluded due to schedule cancellation after randomization, and 239 patients were eventually included in the final analysis. There were no significant differences between the two groups regarding baseline characteristics (P > 0.05). Furthermore, no significant differences were observed in terms of advanced adenoma detection rate (AADR), polyp detection rate (PDR), bowel preparation scale (BBPS), bubble scale (BS), and withdrawal time between the two groups (P > 0.05). However, compared with the conventional group, the cecal insertion time (CIT) of the abdominal bandage group was significantly shortened (279.00 (234.50-305.75) vs. 421.00 (327.00-485.00), P < 0.001), and the CCR (96.7% vs. 88.2%, P = 0.01) and adenoma detection rate (ADR) (47.5% vs. 32.8%, P < 0.001) were improved. Besides, logistic regression analysis showed that body mass index (BMI) and abdominal compression bandage were associated with CCR.

CONCLUSIONS

Abdominal compression bandages could effectively shorten CIT and improve CCR and ADR for obese patients during a routine colonoscopy. This trial is registered with the Chinese Clinical Trial Registry (No. ChiCTR2100043556).

Factors associated with prolonged cecal insertion time in patients undergoing water exchange colonoscopy

BACKGROUND AND AIM

Water exchange is superior to air insufflation in reducing discomfort and increasing adenoma detection during colonoscopy. However, prolonged cecal insertion time is a drawback. This study aims to investigate the factors affecting cecal insertion during water exchange colonoscopy.

METHODS

We pooled data from five randomized clinical trials that included patients undergoing water exchange colonoscopy. Logistic analysis was performed to determine the independent factors associated with prolonged cecal insertion time (> 15 min).

RESULTS

The cohort included 912 patients (493 men and 419 women) with a median age of 57 years (interquartile range, 49-64 years). The median cecal insertion time was 13.5 min (interquartile range, 10.9-17.0 min). Multivariate logistic regression analysis indicated that female sex, body mass index < 25 kg/m² , a history of constipation, no sedation, less experienced endoscopist, Boston Bowel Preparation Scale score ≤ 6, infused water volume during insertion ≥ 1000 mL, and scope length at the cecum ≥ 85 cm were associated with prolonged cecal insertion time. With increasing volume of infused water (1000-2000 mL), the median cecal insertion time increased gradually from 11.4 to 23.0 min (P < 0.001).

CONCLUSIONS

The current study identified independent factors associated with prolonged cecal insertion time during water exchange colonoscopy. Several factors are modifiable to achieve a shorter insertion time, including better bowel preparation, the use of sedation, more experienced endoscopist, infusing less water during insertion, and maintaining a shorter scope length.

The impact of submucosal fatty tissue during colon endoscopic submucosal dissection in a western center

OBJECTIVES

Obesity is associated with submucosal fatty tissue. The main aim of this study was to assess the impact of submucosal fatty tissue on the success of colonic endoscopic submucosal dissection (C-ESD) in a western population.

METHODS

This was a retrospective analysis of 125 consecutive C-ESDs performed between October 2015 and July 2017. Fatty tissue sign was defined as positive when the submucosal layer was covered with fatty tissue. The complexity of performing an ESD was assessed by the performing endoscopist, defined by the occurrence of intraprocedural perforation, inability to complete an en-bloc resection or a procedure time exceeding 180 min.

RESULTS

Fatty tissue sign positive was present in 44.8% of the procedures. There were 28 (22.4%) c-ESD defined as complex. Factors associated with complex ESD included; fatty tissue sign [odds ratio (OR) 12.5; 95% confidence interval (CI), 1.9-81.9; P = 0.008], severe fibrosis (OR 148.6; 95% CI, 6.6-3358.0; P = 0.002), poor maneuverability (OR 267.4; 95% CI, 11.5-6212.5; P < 0.001) and polyp size ≥35 mm (OR 17.2; 95% CI, 2.6-113.8; P = 0.003). In patients demonstrating the fatty tissue sign, BMI and waist-to-height ratio (WHtR) were higher (27.8 vs. 24.7; P < 0.001 and 0.56 vs. 0.49; P < 0.001, respectively) and en-bloc resection was achieved less frequently (76.8 vs. 97.1%, P = 0.001). Multivariate analysis revealed higher risk of fatty tissue sign positive associated with WHtR ≥0.52 (OR 26.10, 95% CI, 7.63-89.35, P < 0.001).

CONCLUSION

This study demonstrates that the fatty tissue sign contributes to procedural complexity during C-ESD. Central obesity correlates with the likelihood of submucosal fatty tissue and as such should be taken into account when planning procedures.

TEACHING BASIC COLONOSCOPY SKILLS: QUALITY AND SAFETY STANDARDS CAN BE FULFILLED IN AN OUTPATIENT UNIVERSITY CENTER

BACKGROUND

Recent studies have shown that endoscopy fellows can perform colonoscopy effectively and safely. However, little is known about the performance of surgical residents without prior knowledge of endoscopic techniques.

OBJECTIVE

To assess whether quality indicators were met at an outpatient endoscopy center and whether surgical residents, without prior upper or lower endoscopy skills, could perform colonoscopy adequately.

METHODS

A prospective non-randomized cohort study was undertaken. All exams were performed either by assistant physicians or by residents. Quality measures were compared between those groups.

RESULTS

A total of 2720 colonoscopies were analyzed. In the resident group, we observed older patients (57.7±12.7 years vs 51.5±14.5 years, P<0.001), a higher prevalence of screening colonoscopies (52% vs 39.4%, P<0.001) and a higher prevalence of colorectal cancer (6.4% vs 1.8%, P<0.001). The cecal intubation rate was higher in the attending group (99.9% vs 89.3%; P<0.001). The polyp detection rate was 40.8%, and no differences were observed between the studied groups. The residents had a higher rate of perforation in all exams (0.4% vs 0%; P=0.02). Postpolypectomy bleeding and 7-day readmission rates were the same (0.2%). All readmissions in 7 days occurred due to low digestive bleeding, and none required intervention.

CONCLUSION

Quality indicators were met at a university outpatient endoscopy center; however, medical residents achieved lower rates of cecal intubation and higher rates of perforation than the attending physicians.

Colorectal Cancer-Derived CAT1-Positive Extracellular Vesicles Alter Nitric Oxide Metabolism in Endothelial Cells and Promote Angiogenesis

Accumulating scientific evidences strongly support the importance of cancer-derived extracellular vesicles (EV) in organization of tumor microenvironment and metastatic niches, which are also considered as ideal tools for cancer liquid biopsy. To uncover the full scope of proteomic information packaged within EVs secreted directly from human colorectal cancer, we cultured surgically resected viable tissues and obtained tissue-exudative EVs (Te-EV). Our quantitative profiling of 6,307 Te-EV proteins and 8,565 tissue proteins from primary colorectal cancer and adjacent normal mucosa (n = 17) allowed identification of a specific cargo in colorectal cancer-derived Te-EVs, high-affinity cationic amino acid transporter 1 (CAT1, P = 5.0 × 10^-3, fold change = 6.2), in addition to discovery of a new class of EV markers, VPS family proteins. The EV sandwich ELISA confirmed escalation of the EV-CAT1 level in plasma from patients with colorectal cancer compared with healthy donors (n = 119, P = 3.8 × 10^-7). Further metabolomic analysis revealed that CAT1-overexpressed EVs drastically enhanced vascular endothelial cell growth and tubule formation via upregulation of arginine transport and downstream NO metabolic pathway. These findings demonstrate the potency of CAT1 as an EV-based biomarker for colorectal cancer and its functional significance on tumor angiogenesis. IMPLICATIONS: This study provides a proteome-wide compositional dataset for viable colorectal cancer tissue-derived EVs and especially emphasizes importance of EV-CAT1 as a key regulator of angiogenesis.