Cap-Assisted Chromoendoscopy Using a Mounted Cap Versus Standard Colonoscopy for Adenoma Detection

Colorectal adenoma detection rate using texture and color enhancement imaging versus white light imaging with chromoendoscopy: a propensity score matching study

BACKGROUND AND AIM

Few studies have evaluated the adenoma detection rate (ADR) of colonoscopy with texture and color enhancement imaging (TXI), a novel image-enhancing technology. This study compares the detection of colorectal polyps using TXI to that using white light imaging (WLI).

METHODS

This single-center retrospective study used propensity-matched scoring based on the patients' baseline characteristics (age, sex, indication, bowel preparation, endoscopist, colonoscope type, and withdrawal time) to compare the results of patients who underwent chromoendoscopy using WLI or TXI at the Toyoshima Endoscopy Clinic. The differences in polyp detection rates and the mean number of detected polyps per colonoscopy were determined between the TXI and WLI groups.

RESULTS

After propensity score matching, 1970 patients were enrolled into each imaging modality group. The mean patient age was 57.2 ± 12.5 years, and 44.5% of the cohort were men. The ADR was higher in the TXI group than in the WLI group (55.0% vs 49.4%, odds ratio: 1.25). High-risk ADR were more common in the TXI group than in the WLI group (17.6% vs 12.8%; OR: 1.45). The mean number of adenomas per colonoscopy (APC) was higher in the TXI group than in the WLI group (1.187 vs 0.943, OR: 1.12). APC with a flat morphology (1.093 vs 0.848, OR: 1.14) and APC of <6 mm (0.992 vs 0.757, OR: 1.16) were higher in the TXI group than in the WLI group.

CONCLUSION

Compared to WLI, TXI improved the ADR in patients who underwent chromoendoscopy based on actual clinical data.

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.

Linked-Color Imaging Detects More Colorectal Adenoma and Serrated Lesions: An International Randomized Controlled Trial

BACKGROUND & AIMS

Effects of linked-color imaging (LCI) on colorectal lesion detection and colonoscopy quality remain controversial. This study compared the detection rates of adenoma and other precursor lesions using LCI vs white-light imaging (WLI) during screening, diagnostic, and surveillance colonoscopies.

METHODS

This randomized controlled trial was performed at 11 institutions in 4 Asian countries/regions. Patients with abdominal symptoms, a primary screening colonoscopy, positive fecal immunochemical test results, or undergoing postpolypectomy surveillance were recruited and randomly assigned in a 1:1 ratio to either the LCI or high-definition WLI group. The primary outcome was adenoma detection rate (ADR). Secondary outcomes were polyp detection rate, advanced ADR, sessile serrated lesion (SSL) detection rate, and the mean number of adenomas per colonoscopy. The recommended surveillance schedule distribution after trial colonoscopy was analyzed.

RESULTS

Between November 2020 and January 2022, there were 3050 participants (LCI, n = 1527; WLI, n = 1523) recruited. The LCI group ADR was significantly higher than the WLI group ADR using intention-to-treat (58.7% vs 46.7%; P < .01) and per-protocol analyses (59.6% vs 46.4%; P < .01). The LCI group polyp detection rates (68.6% vs 59.5%; P < .01), SSL detection rates (4.8% vs 2.8%; P < .01), and adenomas per colonoscopy (1.48 vs 1.02; P < .01) also were significantly higher. However, the advanced ADR was not significantly different (13.2% vs 11.0%; P = .06). Significantly more patients in the LCI group had shorter recommended surveillance schedules than the WLI group (P < .01).

CONCLUSIONS

Compared with WLI, LCI improved adenoma and other polyp detection rates, including SSLs, resulting in alteration of the recommended surveillance schedule after screening, diagnostic, and postpolypectomy surveillance colonoscopies.

TRIAL REGISTRATION NUMBER

UMIN000042432 (https://www.umin.ac.jp/ctr/index.htm).

Comparison of Linked Color Imaging and White Light Imaging Colonoscopy for Detection of Colorectal Adenoma Requiring Endoscopic Treatment: A Single-Center Randomized Controlled Trial

BACKGROUND

Linked color imaging (LCI) improves detection of colorectal neoplastic lesions during colonoscopy. However, polyps <5 mm in diameter often do not require resection, and the benefits of LCI are unclear for detection of colorectal polyps ≥5 mm that are indicated for endoscopic resection in clinical practice. This randomized controlled trial compared rates of detection of adenoma polyps, stratified by size, for LCI and white light imaging (WLI).

METHODS

We compared ADR (5 mm-) and PDR (5 mm-), which were defined as the proportion of patients with at least one adenoma or polyp with a diameter of 5 mm or larger in the LCI and WLI groups. Moreover, we estimated ADR and PDR for diameters between 5 and 10 mm (ADR (5-9 mm), PDR (5-9 mm) ) and for diameters larger than 10 mm (ADR (10 mm-), PDR (10 mm-) ).

RESULTS

Data from 594 patients (LCI, n=305; WLI, n=289) were analyzed. ADR (5 mm-) and PDR (5 mm-) were significantly higher in the LCI group than in the WLI group (ADR (5 mm-): P=0.016, PDR (5 mm-): P=0.020). In the assessment of adenoma and polyp size, ADR (5-9 mm) and PDR (5-9 mm) were significantly higher in the LCI group than in the WLI group, although no significant differences were seen in ADR (10 mm-) and PDR (10 mm-) between these groups.

CONCLUSIONS

Polyps ≥5 mm, which are indicated for endoscopic treatment, were more easily visualized with LCI mode than with WLI mode. The improvement in detection rate was obvious for polyps <10 mm, which are easier to miss.

Mucosal imaging in colon polyps: New advances and what the future may hold

An expanding range of advanced mucosal imaging technologies have been developed with the goal of improving the detection and characterization of lesions in the gastrointestinal tract. Many technologies have targeted colorectal neoplasia given the potential for intervention prior to the development of invasive cancer in the setting of widespread surveillance programs. Improvement in adenoma detection reduces miss rates and prevents interval cancer development. Advanced imaging technologies aim to enhance detection without significantly increasing procedural time. Accurate polyp characterisation guides resection techniques for larger polyps, as well as providing the platform for the “resect and discard” and “do not resect” strategies for small and diminutive polyps. This review aims to collate and summarise the evidence regarding these technologies to guide colonoscopic practice in both interventional and non-interventional endoscopists.

Progress in understanding of factors related to colonoscopic adenoma detection rate

Adenoma detection rate (ADR) is the proportion of average-risk patients undergoing screening colonoscopy in whom an adenoma is found, and it is an important quality indicator of colonoscopy. ADR is closely related to the risk of interval colorectal cancer. A deeply study of ADR is essential for endoscopists. In this paper, we review the progress in the understanding of factors related to ADR before, during, and after colonoscopy, as well as several issues worthy of attention.

Linked color imaging, mucosal exposure device, their combination, and standard colonoscopy for adenoma detection: a randomized trial

BACKGROUND AND AIMS

By different mechanisms, image-enhancement techniques (linked color imaging [LCI]) and mucosal exposure devices (Endocuff-assisted colonoscopy [EAC]) can improve the adenoma detection rate (ADR) during screening colonoscopy. The impact of the combination of the 2 techniques has never been studied. This study aimed to compare the ADR between the combination of LCI and EAC (LCI+EAC), LCI alone, EAC alone, and standard high-definition (HD) colonoscopy.

METHODS

This prospective randomized controlled trial included participants who underwent screening colonoscopy. Participants were randomized to LCI+EAC, LCI, EAC, and standard HD colonoscopy. All colonoscopies were performed by endoscopists with a recorded ADR ≥35%. The primary outcome was the ADR. Secondary outcomes were proximal ADR (pADR) and the mean number of adenomas per colonoscopy (APC).

RESULTS

One thousand participants were included in the study. The LCI+EAC group provided the highest ADR and pADR. The ADRs in the LCI+EAC, LCI, EAC, and standard HD colonoscopy groups were 57.2%, 52.8%, 51.6%, and 47.6%, respectively, with pADRs of 38.4%, 34.8%, 33.6%, and 28.0%, respectively. The mean numbers of APC were 1.28, 1.20, 1.16, and .89, respectively. After a multiple comparison adjustment, a significant difference in pADR was only observed between the LCI+EAC and standard HD colonoscopy groups (difference, 10.3 percentage points; 95% confidence interval, .02%-17.4%; P = .05). The incidence rate ratios of the adenoma numbers were significantly higher in the LCI+EAC (1.43), LCI (1.34), and EAC (1.30) groups relative to the standard HD colonoscopy group (.89) (P < .009 for all comparisons).

CONCLUSIONS

The combination of LCI and EAC can significantly improve the detection of pADR and APC but not ADR by high-ADR performers. (Clinical trial registration number: TCTR20190319001.).

A Parallel Comparison Method of Early Gastric Cancer: The Light Transmission-Assisted Pathological Examination of Specimens of Endoscopic Submucosal Dissection

Objective

It is always challenging to diagnose and characterize early gastric cancer surrounded by non-cancerous mucosa, including the malignant diagnosis and extent and depth of the lesions. Therefore, we developed a light transmission-assisted pathological examination to diagnose and characterize early gastric cancer. Here, we performed a parallel comparison between the light transmission-assisted pathological examination under endoscopy and the histological examination for the diagnosis of early gastric cancer.

Methods

First, the endoscopic submucosal dissection (ESD) specimen was first placed on the surface of the light-emitting diode lamp to observe the mucosal surface structure and blood vessels. Second, the sliced and embedded tissue strips were cut into 3-µm sections for hematoxylin and eosin staining. Third, the histopathology of each section was projected onto a macroscopic image. Finally, the macroscopic and microscopic changes in the ESD specimens observed under endoscopy were compared. Seventy cases of early gastric adenocarcinoma were diagnosed and characterized using this new method.

Results

Using the conventional pathological method, the demarcation line of the lesions was seen in 40 of 70 (57.1%) cases. Furthermore, no surface structure or microvascular changes were observed in any of the cases. Based on the light transmission-assisted pathological examination, 58 of 70 (82.9%) cases presented clear edges of neoplastic and non-neoplastic epithelia, with a classifiable surface structure (88.6%) and microvascular type (78.8%).

Conclusions

This pilot method provided a practical bridge between endoscopic and pathological examinations. Compared to the histological examination, the light transmission-assisted pathological examination was an easier and more precise way to match the in vivo endoscopic observation and in vitro pathological examination.

Colonoscopy Versus Fecal Immunochemical Test for Reducing Colorectal Cancer Risk: A Population-Based Case-Control Study

INTRODUCTION

Use of colonoscopy or the fecal immunochemical test (FIT) for colorectal cancer (CRC) prevention is supported by previous studies. However, there is little specific evidence regarding comparative effectiveness of colonoscopy or FIT for reducing CRC risk. In this study, we compared the association of CRC risk with colonoscopy and FIT using a nationwide database.

METHODS

This population-based case-control study used colonoscopy and FIT claims data from the Korean National Health Insurance System from 2002 to 2013. Data were analyzed from 61,221 patients with newly diagnosed CRC (case group) and 306,099 individuals without CRC (control group). Multivariable logistic regression models were used to evaluate the association between CRC and colonoscopy or FIT.

RESULTS

Colonoscopy was associated with a reduced subsequent CRC risk (adjusted odds ratio [OR] 0.29). Stronger associations were found between colonoscopy and distal CRC, compared with proximal CRC (0.24 vs 0.47). In an analysis stratified by sex, the association was weaker in female subjects compared with male subjects (0.33 vs 0.27). Any FIT exposure was associated with CRC risk with an OR of 0.74; this association was stronger for distal cancer. As the frequency of cumulative FIT assessments increased (from 1 to ≥5), the OR of FIT exposure for CRC gradually decreased from 0.81 to 0.45.

DISCUSSION

The association of colonoscopy or FIT with reduced CRC risk was stronger for distal CRC than for proximal CRC. FIT showed less CRC risk reduction than colonoscopy. However, as the frequency of cumulative FIT assessments increased, the association with CRC prevention became stronger.

Oral indigo carmine for the detection of colon adenoma

OBJECTIVES

Colonoscopy is currently considered the optimal method to detect colorectal neoplasia; however, some adenomas remain undetected. While indigo carmine staining with a dye-spray catheter has demonstrated promising results for reducing the miss rate, we investigated the oral indigo carmine method. The aim of this study was to determine whether oral indigo carmine intake before standard colonoscopy increases the adenoma (and adenocarcinoma) detection rate (ADR) or the mean number of adenomas per patient (MAP).

MATERIALS AND METHODS

The oral indigo carmine method was performed from April 2018 to July 2020 in two hospitals. Data were collected in a prospective manner and compared to the conventional group whose data were collected retrospectively and consecutively from January 2016 to March 2018. All data were anonymized.

RESULTS

Among the 704 patients included, colonoscopies were completely performed in 693 patients (347 in the indigo group). The ADR did not significantly differ between the groups: 42.3% vs. 40.3% (indigo vs. conventional group; odds ratio: 1.13; 95% confidence interval: 0.9-1.33, p = .33). The MAP was significantly greater in the indigo group (1.15) than that in the conventional group (0.82; p = .009). The cecal intubation rate and time to cecal intubation did not differ between the indigo and conventional group (98.6% vs. 98.3%, p = .83, and 6.2 min vs. 5.9 min, p = .39, respectively).

CONCLUSION

The routine use of oral indigo carmine does not lead to a higher ADR despite the higher MAP.

Endocuff-assisted colonoscopy versus cap-assisted colonoscopy for adenoma detection rate: A meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Add-on devices have been widely used in clinical practice. The aim of this meta-analysis was to compare the adenoma detection rate between Endocuff-assisted colonoscopy (EAC) and cap-assisted colonoscopy (CAC).

METHODS

PubMed, EMBASE, SCOPUS, and Cochrane databases were searched. Outcomes included adenoma detection rate, cecal intubation rate, cecal intubation time, and withdrawal time. Dichotomous data were pooled to obtain the odds ratio or risk ratio. Continuous data were pooled using the mean difference.

RESULTS

Of the 240 articles reviewed, six randomized controlled trials were included, with a total of 1994 patients. In the meta-analysis, no statistical difference in adenoma detection rate was detected between EAC and CAC (47.0% vs 45.1%; P = 0.33). EAC significantly improved detection rate of diminutive adenomas/polyps compared with CAC (P = 0.01). Cecal intubation was achieved in 96.5% in EAC group and 97.9% in CAC group (P = 0.04). Besides, no statistical difference was found in cecal intubation time (P = 0.86), withdrawal time (P = 0.88), small adenomas/polyps (P = 0.60), or large adenomas/polyps (P = 0.95).

CONCLUSION

EAC and CAC have their respective merits. EAC significantly improve the detection of diminutive adenomas/polyps. CAC was better in cecal intubation rate.

Antibiotic use and risk of colorectal cancer: a systematic review and dose-response meta-analysis

BACKGROUND

It is understudied whether the posed association of oral antibiotics with colorectal cancer (CRC) varies between antibiotic spectrums, colorectal continuum, and if a non-linear dose-dependent relationship is present.

DESIGN

Three electronic databases and a trial platform were searched for all relevant studies, from inception until February 2020, without restrictions. Random-effects meta-analyses provided pooled effect-sizes (ES) with 95% confidence intervals (CI). Dose-response analyses modelling the relationship between number of days exposed to antibiotics and CRC risk were extended to non-linear multivariable random-effects models.

RESULTS

Of 6483 identified publications ten were eligible, including 4.1 million individuals and over 73,550 CRC cases. The pooled CRC risk was increased among individuals who ever-used antibiotics (ES = 1.17, 95%CI 1.05-1.30), particularly for broad-spectrum antibiotics (ES = 1.70, 95%CI 1.26-2.30), but not for narrow-spectrum antibiotic (ES = 1.11, 95% 0.93-1.32). The dose-response analysis did not provide strong evidence of any particular dose-response association, and the risk patterns were rather similar for colon and rectal cancer.

DISCUSSION

The antibiotic use associated CRC risk seemingly differs between broad- and narrow-spectrum antibiotics, and possibly within the colorectal continuum. It remains unclear whether this association is causal, requiring more mechanistic studies and further clarification of drug-microbiome interactions.