Cap-assisted colonoscopy: a meta-analysis of high-quality randomized controlled trials

Improvement in Adenoma Detection Rate with Distal Attachment Device Endo-Wing™-Assisted Colonoscopy: A Randomized Control Trial

Aim: Endo-Wing™ is a soft silicone device with six wing-like projections attached at the end of the colonoscope that provides superior visualization by flattening the colonic fold and helps to maintain a central view of the colonoscope during withdrawal. This study aims to compare the adenoma detection rate (ADR) between standard colonoscopy and Endo-Wing™-assisted colonoscopy. Methods: This is a single-center, single-blind, parallel-group, randomized, actively controlled, exploratory clinical trial conducted between July 2019 and April 2020. Participants aged 45 and above who were symptomatic of colorectal cancer (CRC) or with a history of adenoma and under active surveillance were included. Exclusion criteria included colonic strictures, tumors, active colitis, a previous history of polyposis syndrome, colostomy/ileostomy, or a BPPS score of 0. Participants were subsequently randomized to receive standard colonoscopy (n = 96) or Endo-Wing™-assisted colonoscopy (n = 96) at a 1:1 ratio using a central block randomization method with varying block sizes. The primary endpoint was the ADR, and the differences between the two groups were evaluated using univariable statistical methods. Results: The ADR, the number of adenomas, and the size of adenomas in the Endo-Wing™-assisted colonoscopy group were significantly higher compared to standard colonoscopy (p = 0.005, 0.035, and 0.035, respectively). Cecal intubation rates were similar in both groups (p > 0.999). The proportions of colonoscopy requiring increased sedation and standard sedation were similar in both groups (p = 0.613). No adverse effects of bleeding, perforation, and device dislodgement were reported in both groups. Conclusions: This study concludes that Endo-Wing™-assisted colonoscopy improves the ADR compared to standard colonoscopy.

One in three adenomas could be missed by white-light colonoscopy - findings from a systematic review and meta-analysis

BACKGROUND

White light (conventional) colonoscopy (WLC) is widely used for colorectal cancer screening, diagnosis and surveillance but endoscopists may fail to detect adenomas. Our goal was to assess and synthesize overall and subgroup-specific adenoma miss rates (AMR) of WLC in daily practice.

METHODS

We conducted a systematic review in MEDLINE, EMBASE, Cochrane Library, and grey literature on studies evaluating diagnostic WLC accuracy in tandem studies with novel-colonoscopic technologies (NCT) in subjects undergoing screening, diagnostic or surveillance colonoscopy. Information on study design, AMR overall and specific for adenoma size, histology, location, morphology and further outcomes were extracted and reported in standardized evidence tables. Study quality was assessed using the QUADAS-2 tool. Random-effects meta-analyses and meta-regression were performed to estimate pooled estimates for AMR with 95% confidence intervals (95% CI) and to explain heterogeneity.

RESULTS

Out of 5,963 identified studies, we included sixteen studies with 4,101 individuals in our meta-analysis. One in three adenomas (34%; 95% CI: 30-38%) was missed by WLC in daily practice individuals. Subgroup analyses showed significant AMR differences by size (36%, adenomas 1-5 mm; 27%, adenomas 6-9 mm; 12%, adenomas ≥ 10 mm), histology (non-advanced: 42%, advanced: 21%), morphology (flat: 50%, polypoid: 27%), but not by location (distal: 36%, proximal: 36%).

CONCLUSIONS

Based on our meta-analysis, one in three adenomas could be missed by WLC. This may significantly contribute to interval cancers. Our results should be considered in health technology assessment when interpreting sensitivity of fecal occult blood or other screening tests derived from studies using WLC as "gold standard".

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.

Sessile serrated lesion prevalence and factors associated with their detection: a post-hoc analysis of a multinational randomized controlled trial from Asia

BACKGROUND

Sessile serrated lesions (SSLs) are associated with an increased risk of colorectal cancer. Data on the prevalence of SSLs in Asia are limited. We performed this study to estimate the prevalence of SSLs in Asia and to explore endoscopic factors that are associated with SSL detection.

METHODS

This is a post-hoc analysis of a multicenter randomized controlled trial from four Asian countries/regions that compared adenoma detection rates using linked-color imaging (LCI) and white-light imaging. Colonoscopies were performed in an average-risk population for screening, diagnostic examination, or polyp surveillance. Patients with SSLs were compared against those without SSLs to evaluate for possible predictors of SSL detection using Firth's logistic regression.

RESULTS

2898 participants (mean age 64.5 years) were included in the analysis. The estimated prevalence of SSLs was 4.0% (95%CI 3.4%-4.8%), with no sex or age group differences. On multivariable analysis, use of LCI (adjusted odds ratio [aOR] 1.63, 95%CI 1.10-2.41), experienced endoscopists (aOR 1.94, 95%CI 1.25-3.00), use of transparent cap (aOR 1.75, 95%CI 1.09-2.81), and longer withdrawal time (aOR 1.06, 95%CI 1.03-1.10) were independently associated with SSL detection. Synchronous adenoma detection (aOR 1.89, 95%CI 1.20-2.99) was also predictive of SSL detection.

CONCLUSION

The prevalence of SSLs in Asia is 4.0%. Use of LCI or a transparent cap, greater endoscopist experience, and longer withdrawal time were all associated with increased SSL detection.

The role of cap-assisted endoscopy and its future implications

Cap-assisted endoscopy refers to a procedure in which a short tube made of a polymer (mostly transparent) is attached to the distal tip of the endoscope to enhance its diagnostic and therapeutic capabilities. It is reported to be particularly useful in: (1) minimizing blind spots during screening colonoscopy, (2) providing a constant distance from a lesion for clear visualization during magnifying endoscopy, (3) accurately assessing the size of various gastrointestinal lesions, (4) preventing mucosal injury during foreign body removal, (5) securing adequate workspace in the submucosal space during endoscopic submucosal dissection or third space endoscopy, (6) providing an optimal approach angle to a target, and (7) suctioning mucosal and submucosal tissue with negative pressure for resection or approximation. Here, we review various applications of attachable caps in diagnostic and therapeutic endoscopy and their future implications.

Image enhanced colonoscopy: updates and prospects-a review

Colonoscopy has been proven to be a successful approach in both identifying and preventing colorectal cancer. The incorporation of advanced imaging technologies, such as image-enhanced endoscopy (IEE), plays a vital role in real-time diagnosis. The advancements in endoscopic imaging technology have been continuous, from replacing fiber optics with charge-coupled devices to the introduction of chromoendoscopy in the 1970s. Recent technological advancements include "push-button" technologies like autofluorescence imaging (AFI), narrowed-spectrum endoscopy, and confocal laser endomicroscopy (CLE). Dye-based chromoendoscopy (DCE) is falling out of favor due to the longer time required for application and removal of the dye and the difficulty of identifying lesions in certain situations. Narrow band imaging (NBI) is a technology that filters the light used for illumination leading to improved contrast and better visibility of structures on the mucosal surface and has shown a consistently higher adenoma detection rate (ADR) compared to white light endoscopy. CLE has high sensitivity and specificity for polyp detection and characterization, and several classifications have been developed for accurate identification of normal, regenerative, and dysplastic epithelium. Other IEE technologies, such as blue laser imaging (BLI), linked-color imaging (LCI), i-SCAN, and AFI, have also shown promise in improving ADR and characterizing polyps. New technologies, such as Optivista, red dichromatic imaging (RDI), texture and color enhancement imaging (TXI), and computer-aided detection (CAD) using artificial intelligence (AI), are being developed to improve polyp detection and pathology prediction prior to widespread use in clinical practice.

Multicenter propensity score-matched analysis comparing short versus long cap-assisted colonoscopy for acute hematochezia

BACKGROUND AND AIM

While short and long attachment caps are available for colonoscopy, it is unclear which type is more appropriate for stigmata of recent hemorrhage (SRH) identification in acute hematochezia. This study aimed to compare the performance of short versus long caps in acute hematochezia diagnoses and outcomes.

METHODS

We selected 6460 patients who underwent colonoscopy with attachment caps from 10 342 acute hematochezia cases in the CODE BLUE-J study. We performed propensity score matching (PSM) to balance baseline characteristics between short and long cap users. Then, the proportion of definitive or presumptive bleeding etiologies found on the initial colonoscopy and SRH identification rates were compared. We also evaluated rates of blood transfusions, interventional radiology, or surgery, as well as the rate of rebleeding and mortality within 30 days after the initial colonoscopy.

RESULTS

A total of 3098 patients with acute hematochezia (1549 short cap and 1549 long cap users) were selected for PSM. The rate of colonic diverticular bleeding (CDB) diagnosis was significantly higher in long cap users (P = 0.006). While the two groups had similar rates of the other bleeding etiologies, the frequency of unknown etiologies was significantly lower in long cap users (P < 0.001). The rate of SRH with active bleeding was significantly higher in long cap users (P < 0.001). Other clinical outcomes did not differ significantly.

CONCLUSION

Compared to that with short caps, long cap-assisted colonoscopy is superior for the diagnosis of acute hematochezia, especially CDB, and the identification of active bleeding.

Recent advances in devices and technologies that might prove revolutionary for colonoscopy procedures

INTRODUCTION

Colorectal cancer (CRC) is the third most common malignancy and second leading cause of cancer-related mortality in the world. Adenoma detection rate (ADR), a quality indicator for colonoscopy, has gained prominence as it is inversely related to CRC incidence and mortality. As such, recent efforts have focused on developing novel colonoscopy devices and technologies to improve ADR.

AREAS COVERED

The main objective of this paper is to provide an overview of advancements in the fields of colonoscopy mechanical attachments, artificial intelligence-assisted colonoscopy, and colonoscopy optical enhancements with respect to ADR. We accomplished this by performing a comprehensive search of multiple electronic databases from inception to September 2023. This review is intended to be an introduction to colonoscopy devices and technologies.

EXPERT OPINION

Numerous mechanical attachments and optical enhancements have been developed that have the potential to improve ADR and AI has gone from being an inaccessible concept to a feasible means for improving ADR. While these advances are exciting and portend a change in what will be considered standard colonoscopy, they continue to require refinement. Future studies should focus on combining modalities to further improve ADR and exploring the use of these technologies in other facets of colonoscopy.

Unlocking quality in endoscopic mucosal resection

A review of the development of the key performance metrics of endoscopic mucosal resection (EMR), learning from the experience of the establishment of widespread colonoscopy quality measurements. Potential future performance markers for both colonoscopy and EMR are also evaluated to ensure continued high quality performance is maintained with a focus service framework and predictors of patient outcome.

Upskilling Pediatric Ileocolonoscopy

Upskilling in ileocolonoscopy is an important aspect of pediatric endoscopic practice as it enables endoscopists to learn additional skills through education and training to improve outcomes. With the advent of technologies, endoscopy is continuously evolving. Many devices can be applied to improve endoscopy quality and ergonomics. In addition, techniques such as dynamic position change can be employed to increase procedural efficiency and completeness. Key to upskilling is enhancing endoscopists' cognitive, technical and nontechnical skills and the concept of "training the trainer" to ensure trainers have the requisite skills to teach endoscopy effectively. This chapter details aspects of upskilling pediatric ileocolonoscopy.

A randomized prospective study comparing single-balloon-assisted colonoscopy and cap-assisted colonoscopy in patients with previous incomplete conventional colonoscopy

INTRODUCTION

Cecal intubation may be unsuccessful by conventional colonoscopy in some patients. Single-balloon-assisted colonoscopy (SBC) and cap-assisted colonoscopy (CAC) were studied to solve this problem. There was no head-to-head comparison between them.

METHODS

We conducted a randomized study from 2018 to 2021 to compare cecal intubation rate of SBC and CAC in patients with previous incomplete conventional colonoscopy. We recruited patients with incomplete conventional colonoscopy in two hospitals in Hong Kong. Patients were randomized into SBC group and CAC group in 1:1 ratio. In the case of failure in cecal intubation by allocated method, alternative modality would be performed as rescue.

RESULTS

Forty-four patients were recruited. Cecal intubation rate was superior in SBC group (22/22, 100%) than CAC group (16/22, 72.7%) (P = 0.02). No difference in cecal intubation time, polyp detection rate, and diagnostic gain in area not examined previously. SBC induced less discomfort (modified Gloucester comfort score 2.14 vs 2.63, P = 0.03) with use of comparable amount of midazolam and fentanyl as CAC. For patients failed cecal intubation by CAC, all (n = 6) were rescued successfully by SBC. Body weight, body mass index (BMI), and waist circumference were greater in rescue subgroup. More patients were obese (BMI ≥ 25 kg/m) in rescue subgroup (67% vs 19%). None in rescue subgroup had history of successful cecal intubation by conventional colonoscopy (0% vs 56%, P = 0.046). However, we failed to demonstrate significant association in multivariate analysis owing to small sample size. No adverse event was noted.

CONCLUSION

SBC is superior to CAC in cecal intubation in patients with previous incomplete conventional colonoscopy.

Optimizing adenoma detection in screening-related colonoscopy

INTRODUCTION

Screening-related colonoscopy is a vital component of screening initiatives to both diagnose and prevent colorectal cancer (CRC), with prevention being reliant upon early and accurate detection of pre-malignant lesions. Several strategies, techniques, and interventions exist to optimize endoscopists' adenoma detection rates (ADR).

AREAS COVERED

This narrative review provides an overview of the importance of ADR and other colonoscopy quality indicators. It then summarizes the available evidence regarding the effectiveness of the following domains in terms of improving ADR: endoscopist factors, pre-procedural parameters, peri-procedural parameters, intra-procedural strategies and techniques, antispasmodics, distal attachment devices, enhanced colonoscopy technologies, enhanced optics, and artificial intelligence. These summaries are based on an electronic search of the databases Embase, PubMed, and Cochrane performed on 12 December 2022.

EXPERT OPINION

Given the prevalence and associated morbidity and mortality of CRC, the quality of screening-related colonoscopy quality is appropriately prioritized by patients, endoscopists, units, and payers alike. Endoscopists performing colonoscopy should be up to date regarding available strategies, techniques, and interventions to optimize their performance.

Efficacy of combination colonoscopy using modified cap-assisted and water-exchange colonoscopy with prone position for detection of colorectal adenomas

The efficacy of cap-assisted and water-exchange colonoscopy, individually or in combination for adenoma detection is well documented. Moreover, prone positioning colonoscopy may also improve adenoma detection by decreasing loop formation. However, the efficacy of triple-combination colonoscopy using the above methods for adenoma detection is unclear. This study aimed to compare the effectiveness of combining modified cap-assisted and water-exchange colonoscopy with prone position (CWP) and conventional colonoscopy (CC) for adenoma detection. A total of 746 patients who underwent either CWP or CC, performed by 2 board-certified gastroenterologists between December 2019 and March 2020, were investigated retrospectively. Cap-assisted colonoscopy was modified using hooking and dragging maneuver. We evaluated the polyp detection rate (PDR), adenoma detection rate (ADR), and the mean number of adenomas detected per procedure (MAP). There was no significant difference in sex, age, the indication of colonoscopy and quality of bowel preparation between the 2 groups. PDR, ADR, and proximal colon MAP were significantly higher in the CWP group than in the CC group (PDR: 84.9% vs 59.8%, P < .01; ADR: 70.1%, vs 49.2%, P < .01; proximal colon MAP: 1.24 vs 0.55, P < .01). CWP is more effective than CC for PDR, ADR, and proximal colon MAP. Although it may facilitate adenoma detection, further studies assessing the synergistic or complementary effects of combining these methods are needed.

Key factors for improving adenoma detection rate

INTRODUCTION

Colonoscopy is a fundamental tool in colorectal cancer (CRC) prevention. Nevertheless, one-fourth of colorectal neoplasms are still missed during colonoscopy, potentially being the main reason for post-colonoscopy colorectal cancer (PCCRC). Adenoma detection rate (ADR) is currently known as the best quality indicator correlating with PCCRC incidence.

AREAS COVERED

We performed a literature review in order to summarize evidences investigating key factors affecting ADR: endoscopists education and training, patient management, endoscopic techniques, improved navigation (exposition defect), and enhanced lesions recognition (vision defect) were considered.

EXPERT OPINION

'Traditional' factors, such as split dose bowel preparation, adequate withdrawal time, and right colon second view, held a significant impact on ADR. Several devices and technologies have been developed to promote high-quality colonoscopy, however artificial intelligence may be considered the most promising tool for ADR improvement, provided that endoscopists education and recording are guaranteed.

Improved adenoma detection by a novel distal attachment device-assisted colonoscopy: a prospective randomized controlled trial

BACKGROUND AND AIMS

WingCap (A&A Medical Supply LLC, Seongnam, South Korea) is a novel distal attachment device for colonoscopy that combines a cap and an existing mucosal exposure device, such as Endocuff Vision (Arc Medical Design Ltd, Leeds, UK) and AmplifEYE (Medivators Inc, Minneapolis, Minn, USA). We aimed to investigate whether WingCap-assisted colonoscopy can improve the adenoma detection rate (ADR) and adenoma per colonoscopy (APC) and simultaneously shorten cecal intubation time compared with standard colonoscopy.

METHODS

We conducted a single-center, prospective, randomized controlled trial for outpatients aged ≥18 years undergoing colonoscopy. The primary outcome was ADR differences with the assistance of WingCap. Secondary outcomes were APC and other colonoscopy quality indicators, such as cecal intubation and withdrawal times.

RESULTS

In total, 537 patients were randomized for WingCap-assisted or standard colonoscopy. Their mean age was 59.3 years, and 48.5% were men. ADR was significantly higher in the WingCap group than in the control group (37.2% vs 26.6%, P = .012). APC was greater with WingCap than with standard colonoscopy (.72 ± 1.34 vs .45 ± 0.97, P = .008), prominently for nonpedunculated (.65 ± 1.25 vs .42 ± .95, P = .015) and diminutive (.42 ± .94 vs .20 ± .64, P = .002) adenomas. With WingCap, ADR and APC significantly increased for beginner endoscopists, whereas a modest increase was seen for experienced endoscopists. There were no differences in cecal intubation and withdrawal times between the 2 arms. No serious adverse event was associated with the use of WingCap.

CONCLUSIONS

WingCap-assisted colonoscopy was tolerable and efficacious for improving ADR and APC compared with standard colonoscopy, especially for nonpedunculated and diminutive adenomas and for beginner endoscopists. (Clinical trial registration number: KCT0005214.).

High-Definition Colonoscopy Compared With Cuff- and Cap-Assisted Colonoscopy: Results From a Multicenter, Prospective, Randomized Controlled Trial

BACKGROUND AND AIMS

Mucosal exposure devices including distal attachments such as the cuff and cap have shown variable results in improving adenoma detection rate (ADR) compared with high-definition white light colonoscopy (HDWLE).

METHODS

We performed a prospective, multicenter randomized controlled trial in patients undergoing screening or surveillance colonoscopy comparing HDWLE to 2 different types of distal attachments: cuff (CF) (Endocuff Vision) or cap (CP) (Reveal). The primary outcome was ADR. Secondary outcomes included adenomas per colonoscopy, advanced adenoma and sessile serrated lesion detection rate, right-sided ADR, withdrawal time, and adverse events. Continuous variables were compared using Student's t test and categorical variables were compared using chi-square or Fisher's exact test using statistical software Stata version16. A P value <.05 was considered significant.

RESULTS

A total of 1203 subjects were randomized to either HDWLE (n = 384; mean 62 years of age; 81.3% males), CF (n = 379; mean 62.7 years of age; 79.9% males) or CP (n = 379; mean age 62.1 years of age; 80.5% males). No significant differences were found among 3 groups for ADR (57.3%, 59.1%, and 55.7%; P = .6), adenomas per colonoscopy (1.4 ± 1.9, 1.6 ± 2.4, and 1.4 ± 2; P = .3), advanced adenoma (7.6%, 9.2%, and 8.2%; P = .7), sessile serrated lesion (6.8%, 6.3%, and 5.5%; P = .8), or right ADR (48.2%, 49.3%, and 46.2%; P = .7). The number of polyps per colonoscopy were significantly higher in the CF group compared with HDWLE and CP group (2.7 ± 3.4, 2.3 ± 2.5, and 2.2 ± 2.3; P = .013). In a multivariable model, after adjusting for age, sex, body mass index, withdrawal time, and Boston Bowel Preparation Scale score, there was no impact of device type on the primary outcome of ADR (P = .77). In screening patients, CF resulted in more neoplasms per colonoscopy (CF: 1.7 ± 2.6, HDWLE: 1.3 ± 1.7, and CP: 1.2 ± 1.8; P = .047) with a shorter withdrawal time.

CONCLUSIONS

Results from this multicenter randomized controlled trial do not show any significant benefit of using either distal attachment devices (CF or CP) over HDWLE, at least in high-detector endoscopists. The Endocuff may have an advantage in the screening population. (ClinicalTrials.gov, Number: NCT03952611).

Endo-wing versus transparent hood-assisted colonoscopy for colorectal adenoma detection: A randomized controlled trial

BACKGROUND AND AIM

This study aimed to compare the mean number of adenomas in patients undergoing Endo-wing-assisted colonoscopy (EAC) and transparent hood-assisted colonoscopy (TAC).

METHODS

Patients undergoing colonoscopy for positive fecal immunochemical tests, colon polyp surveillance, and evaluation of abdominal symptoms at a single institution were randomly assigned to the EAC or TAC group. The mean number of adenomas per patient, adenoma detection rate, cecal intubation time, withdrawal time, mean number of adenomas per location, and adenoma size were compared.

RESULTS

Overall, 800 patients were enrolled. The EAC and TAC groups comprised 372 and 393 patients, respectively. The groups did not significantly differ with respect to cecal intubation and withdrawal times. The mean number of adenomas per patient was significantly higher in the EAC group (1.13 vs 0.90, P = 0.04), particularly in the sigmoid colon (0.54 [201/372] vs 0.38 [149/393], P = 0.04). The adenoma detection rates were 48.1% and 45.0% in the EAC and TAC groups, respectively, albeit without significant difference between the two groups (P = 0.393). The total number of sessile-type adenomas (0.73 [270/372] vs 0.47 [183/393], P < 0.0001) and small polyps (≤ 5 mm) (0.53 [198/372] vs 0.41 [159/393], P = 0.016) was significantly higher in the EAC group.

CONCLUSION

Endo-wing-assisted colonoscopy is significantly superior to TAC in terms of the mean number of adenomas per patient.

Effect of Linked-color Imaging on the Detection of Adenomas in Screening Colonoscopies

OBJECTIVES

Linked-color imaging (LCI) is a new image-enhancement option that emphasizes mucosal surface contrast, facilitating the differentiation between colorectal lesions and normal mucosa. This study aimed to evaluate the potential of LCI to increase the detection of colorectal adenomas in screening colonoscopies.

METHODS

A prospective randomized study was conducted using white-light imaging (WLI), blue-laser imaging (BLI)-bright and LCI. The outcome measures were adenoma detection rate (ADR), mean number of adenomas per patient, and withdrawal time. Lesion characteristics such as size, morphology, location, and histology were also evaluated.

RESULTS

A total of 205 patients were randomized, and 251 adenomas were detected. The overall ADR was 62%. The ADR was 52.9% for WLI, 62.1% for BLI-bright, and 71% for LCI, and was significantly higher in the LCI group than in the WLI group (P=0.04). No significant difference was observed between LCI and BLI-bright (P=0.28) or BLI-bright and WLI (P=0.30). The mean number of adenomas per patient was 1.01, 1.03, and 1.62 for WLI, BLI-bright, and LCI, respectively, with a significant difference (P=0.02). Withdrawal time did not differ among the groups. A total of 71 adenomas were detected by WLI, 68 by BLI-bright, and 112 by LCI. There was no difference in the size and morphology of the adenomas detected, nor in the diagnosis of sessile serrated adenomas/polyps.

CONCLUSION

LCI significantly increased the detection of adenomas in screening colonoscopies.

[Endoscopic diagnosis, treatment, and follow-up of polyps of the lower gastrointestinal tract]

BACKGROUND

The endoscopic management of polyps of the lower gastrointestinal tract (l-GIT) has emerged in recent years as a result of numerous technological innovations. However, proven expertise and experience are essential.

OBJECTIVES

Presentation of novel and standard techniques and best-practice recommendations for the characterization and resection of l‑GIT polyps.

METHODS

Recent specialist literature and current guidelines.

RESULTS

High-definition endoscopy should be the standard when performing colonoscopy. The (virtual) chromoendoscopy can improve detection and characterization of polyps, but always requires special expertise and experience of the endoscopist in advanced endoscopic imaging. In this regard, computer-aided-diagnosis (CAD) systems have the potential to support endoscopists in the future. Pedunculated polyps should be removed with a hot snare. Small flat polyps can be resected by cold snare or large forceps. Large, non-pedunculated polyps should be treated in an interdisciplinary approach at a referral center with long-standing experience depending on its malignancy potential. After complete resection of small adenoma without high grade dysplasia, surveillance endoscopy is recommended after 5-10 years. Patients with large adenoma or high grade dysplasia should undergo endoscopy after 3 years and patients with multiple adenoma earlier than 3 years. After incomplete or piecemeal resection or insufficient bowel preparation, near-term endoscopy is recommended.

CONCLUSIONS

Adequate characterization and treatment are essential for the appropriate management of l‑GIT polyps.

Impact of cap-assisted colonoscopy during transendoscopic enteral tubing: A randomized controlled trial

BACKGROUND

Colonic transendoscopic enteral tubing (TET) requires double cecal intubation, raising a common concern of how to save cecal intubation time and make the tube stable. We hypothesized that cap-assisted colonoscopy (CC) might reduce the second cecal intubation time and bring potential benefits during the TET procedure.

AIM

To investigate if CC can decrease the second cecal intubation time compared with regular colonoscopy (RC).

METHODS

This prospective multicenter, randomized controlled trial was performed at four centers. Subjects ≥ 7 years needing colonic TET were recruited from August 2018 to January 2020. All subjects were randomly assigned to two groups. The primary outcome was the second cecal intubation time. Secondary outcomes included success rate, insertion pain score, single clip fixation time, purpose and retention time of TET tube, length of TET tube inserted into the colon, and all procedure-related (serious) adverse events.

RESULTS

A total of 331 subjects were randomized to the RC (n = 165) or CC (n = 166) group. The median time of the second cecal intubation was significantly shorter for CC than RC (2.2 min vs 2.8 min, P < 0.001). In patients with constipation, the median time of second cecal intubation in the CC group (n = 50) was shorter than that in the RC group (n = 43) (2.6 min vs 3.8 min, P = 0.004). However, no difference was observed in the CC (n = 42) and RC (n = 46) groups of ulcerative colitis patients (2.0 min vs 2.5 min, P = 0.152). The insertion pain score during the procedure in CC (n = 14) was lower than that in RC (n = 19) in unsedated colonoscopy (3.8 ± 1.7 vs 5.4 ± 1.9; P = 0.015). Multivariate analysis revealed that only CC (odds ratio [OR]: 2.250, 95% confidence interval [CI]: 1.161-4.360; P = 0.016) was an independent factor affecting the second cecal intubation time in difficult colonoscopy. CC did not affect the colonic TET tube's retention time and length of the tube inserted into the colon. Moreover, multivariate analysis found that only endoscopic clip number (OR: 2.201, 95%CI: 1.541-3.143; P < 0.001) was an independent factor affecting the retention time. Multiple regression analysis showed that height (OR: 1.144, 95%CI: 1.027-1.275; P = 0.014) was the only independent factor influencing the length of TET tube inserted into the colon in adults.

CONCLUSION

CC for colonic TET procedure is a safe and less painful technique, which can reduce cecal intubation time.

Multidirectional Colonoscopy Quality Improvement Increases Adenoma Detection Rate: Results of the Seoul National University Hospital Healthcare System Gangnam Center Colonoscopy Quality Upgrade Project (Gangnam-CUP)

BACKGROUND

To prevent colorectal cancer, high-quality colonoscopy is advocated, undertaken by endoscopists with high adenoma detection rates (ADRs). Despite reports that various factors may impact ADRs, the significance of such factors is still unclear.

AIMS

The analysis was aimed at quality-oriented interventions for boosting ADRs.

METHODS

Study enrollees were adults subjected to screening colonoscopy between September 2013 and August 2016 at the Gangnam Center of Seoul National University Hospital Healthcare System. The investigation entailed six periods (P1-6) of 6 months each, during which serial multidirectional quality improvement efforts were instituted. In particular, we sought to further educate endoscopists, provide feedback on individual ADRs, and introduce a split-dose regimen, gauging results via the Boston Bowel Preparation Score. Changes in polyp detection rates (PDRs) and ADRs were then analyzed.

RESULTS

A total of 13,430 colonoscopies were undertaken by 15 experienced endoscopists. Overall, the ADR increased from 45.6% (P1) to 48.2% (P6, p < 0.001). The PDR, ADR, and advanced adenoma detection rate (AdvADR) showed the greatest increases between P3 and P4 [PDR 67.8% → 71.2% (p < 0.001); ADR 44.1% → 47.7% (p = 0.001); AdvADR 2.3% → 3.3% (p = 0.028)] in keeping with the introduction of a split-dose regimen. The sessile serrated adenoma detection rate (SSADR) increased substantially from 2.1% (P1) to 7.9% (P6, p < 0.001), with the largest gain between P1 and P2, just after education (p = 0.023).

CONCLUSIONS

Successful quality improvement in colonoscopy was achieved through comprehensive multidirectional efforts in education, feedback, and enhanced bowel preparation. Achieving high-level bowel preparation was paramount in ADR improvement. The SSADR was improved through education.

Frontiers of Robotic Colonoscopy: A Comprehensive Review of Robotic Colonoscopes and Technologies

Flexible colonoscopy remains the prime mean of screening for colorectal cancer (CRC) and the gold standard of all population-based screening pathways around the world. Almost 60% of CRC deaths could be prevented with screening. However, colonoscopy attendance rates are affected by discomfort, fear of pain and embarrassment or loss of control during the procedure. Moreover, the emergence and global thread of new communicable diseases might seriously affect the functioning of contemporary centres performing gastrointestinal endoscopy. Innovative solutions are needed: artificial intelligence (AI) and physical robotics will drastically contribute for the future of the healthcare services. The translation of robotic technologies from traditional surgery to minimally invasive endoscopic interventions is an emerging field, mainly challenged by the tough requirements for miniaturization. Pioneering approaches for robotic colonoscopy have been reported in the nineties, with the appearance of inchworm-like devices. Since then, robotic colonoscopes with assistive functionalities have become commercially available. Research prototypes promise enhanced accessibility and flexibility for future therapeutic interventions, even via autonomous or robotic-assisted agents, such as robotic capsules. Furthermore, the pairing of such endoscopic systems with AI-enabled image analysis and recognition methods promises enhanced diagnostic yield. By assembling a multidisciplinary team of engineers and endoscopists, the paper aims to provide a contemporary and highly-pictorial critical review for robotic colonoscopes, hence providing clinicians and researchers with a glimpse of the major changes and challenges that lie ahead.

Cap-Assisted Chromo-Colonoscopy: Are 2 Techniques Better Than None?

Cap-assisted and chromo-colonoscopy are 2 techniques which may increase adenoma detection; however, chromo-colonoscopy is limited by increased time requirement. In this edition of The American Journal of Gastroenterology, Kim et al. present data from a randomized controlled trial comparing standard colonoscopy with an arm using both techniques (CAP/CHROMO). The indigo carmine was applied using a simpler method than previous studies, resulting in shorter times. The CAP/CHROMO adenoma detection was higher than the controls (54.4% vs 44.9%; P < 0.001), but there was no difference for advanced neoplasia. If endoscopists find these data convincing, they should trial these techniques separately because each technique may have a different impact.

The Use of Attachment Devices to Aid in Adenoma Detection

PURPOSE OF REVIEW

With the intent of maximizing adenoma detection rate (ADR), different devices and colonoscopic innovations have been introduced over the past few years. There are a variety of attachment devices available for use in colonoscopy, all intended to improve ADR. In this review, we evaluate the evidence surrounding the available attachment devices and their impact on ADR.

RECENT FINDINGS

Endocuff, Endoring, Transparent cap, G-EYE balloon, and Third Eye Retroscope were all included in this review. Three of the devices, Endocuff, Endoring, and transparent hood or cap, have been shown to increase ADR without significantly altering the use of the colonoscope. Although balloon-assisted colonoscopy is not currently FDA-approved, it has the potential to increase ADR as well.

SUMMARY

Mechanical enhancement has been shown to complement the current forward-viewing colonoscope, and Endocuff appears to be the most beneficial attachment to improve ADR.

Improving serrated adenoma detection rate in the colon by electronic chromoendoscopy and distal attachment: systematic review and meta-analysis

BACKGROUND AND AIMS

The evidence for modification of conventional colonoscopy using either "distal attachments" (DAs; endocap, endocuff, and endoring) or "electronic chromoendoscopy" (EC; narrow-band imaging [NBI], iScan, blue-light imaging, autofluorescence imaging, and linked-color imaging) to improve the detection of serrated adenomas during colonoscopy has shown conflicting results.

METHODS

A comprehensive literature search was performed using Medline, Google Scholar, Embase, and Cochrane Library based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized controlled trials (RCTs) comparing any DA or EC with high-definition white-light colonoscopy for detection of serrated adenomas (sessile serrated adenoma/polyp and traditional serrated adenoma) were included. The primary outcome was serrated adenoma detection rate (SADR) defined as the number of patients with at least 1 serrated adenoma of total patients in that group. The secondary outcome was the number of serrated adenomas per subject. Pooled rates were reported using risk ratio (RR) with 95% confidence interval.

RESULTS

Seventeen studies with 13,631 patients (56% men; age range, 50-66 years) met the inclusion criteria. The use of DAs (RR, 1.21; P = .45) and EC (RR, 1.29; P = .09) during colonoscopy did not show a significant improvement in SADR. The SADR using EC was 6.9% (4 studies) and that with NBI alone was 3.7% (3 studies).

CONCLUSIONS

The results indicate that, except for NBI, the use of DAs or EC during colonoscopy does not improve detection of serrated adenomas in the colon. More RCTs evaluating NBI are needed to explore the effect.

Cap-assisted endoscopy: Do we have enough evidence?

So, is there enough evidence to incorporate CC in clinical practice? If we interpret the literature and the meta-analysis by Nutalapati et al., the answer for the clinically-focused endoscopist, with regard to adenoma detection rate (ADR), at present, may be "no". Significant differences do not necessarily imply clinical benefits and translation into clinical practice. The answer for the improvement of cecal intubation frequency and intubation time by the cap depends on the focus of training commitment, because these effects of the cap may be beneficial, especially for unexperienced endoscopists. It is obvious that further studies are needed. In this line, it is interesting to know, that in a recent meta-analysis of prospective studies, the length of the transparent cap had opposite effects on investigation time and polyp detection rate. Whereas, the anal to cecal time was significantly shortened by a cap length of > 7 mm and a polyp detection rate was significantly improved by a cap length of < 4 mm.