Introduction

Bowel preparation is essential to high quality colonoscopy examination. Whether excellent bowel preparation can increase adenoma detection rate(ADR) comparing with good bowel preparation are still controversial.

Aims & Methods

A prospective, multi-center, observation study was designed to compare ADR between excellent and good bowel preparation based on BBPS in early CRC screening. Subjects aged 40 that received PEG bowel preparation were enrolled. Subject characteristics, bowel preparation quality and colonoscopy data were collected. BBPS score 8-9 was defined as excellent and 6-7 as good. Primary endpoint was ADR. Secondary endpoints included polyp detection rate (PDR), advanced adenoma detection rate (AADR), and the detection rate of different diameter lesions (≤5mm, 6-9mm, ≥10mm).

Results

1503 subjects (aged 40-75, ITT population) from 14 hospitals enrolled, 723 (48.1%) got excellent quality of bowel preparation, 707（47.0%）got good quality of bowel preparation. ADR was significant higher in excellent quality group (35.8% vs 26.9%, P<0.001), especially in trans (13.0% vs 9.6%, P=0.036) and right colon(12.5% vs 8.2%, P=0.008)， numerical higher but no significant difference for left colon（23.5% vs 19.8%，P=0.089）. Excellent quality group had significant higher PDR (57.0% vs 45.1%, P<0.001), especially in left (44.7% vs 35.6%, P<0.001) and trans colon(18.9% vs 14.1%, P=0.015)，numerical higher but no significant difference for right colon（16.0% vs 14.0%，P=0.280）. AADR was also significant higher in excellent quality group (3.2% vs 1.4%, P=0.026) . ≤5mm lesions detection rate was significant higher in excellent quality group (47.6% vs 35.4%, P<0.001), no significant difference for the lesions of 6-9mm/≥10mm. PP set on analysis supported these result. Sex(female 53.9% vs male 47.1%，RR: 1.1, 95%CI[1.0-1.3], P<0.001), risk factors of inadequate bowel preparation (no 60.9% vs yes 42.8%, RR 1.4, 95%CI[1.3-1.6, P<0.001]), bowel preparation regiment (split dose 53.7% vs one dose 46.3%, RR1.1, 95%CI [1.1-1.2], P<0.001), PEG volume( 4L 53.4% vs <4L 46.6%， RR 1.4, 95%CI[1.3-1.6], P<0.001), diet compliance (full compliance 52.2% vs other 44.26%, RR: 1.2, 95%CI[1.0, 1.4], P=0.015) as well as run-away time（2-5hour 53.8% vs other 46.2%, RR: 1.1, 95%CI[1.0, 1.3], P=0.017）were significant associated factors of excellent bowel preparation.
Table1 Lesion Detection Rate Comparing Between Excellent and Good Bowel Preparation (ITT population)

Conclusion

We should seek excellent bowel preparation due to higher ADR, PDR and AADR, especially for ≤5mm lesions. For male and populations with inadequate bowel preparation risk factors, enhance diet education, 4L PEG, split dose and right run-away time could help to get excellent bowel preparation.

Introduction

The diagnostic accuracy of colorectal cancer (CRC) screening via colonoscopy is influenced by the quality of bowel preparation. The adenoma detection rate is another well-known quality measure for CRC screening colonoscopies. Counting the total number of adenomas identified during each colonoscopy can provide a more comprehensive assessment of the procedure's effectiveness. Adenomas that are 1 cm or larger, exhibit high-grade dysplasia, or have a villous architecture are considered advanced adenomas and carry a higher risk of progressing to adenocarcinoma.

Aims & Methods

The aims of our study were to assess whether there was an association between the adequacy of bowel preparation and both adenoma detection rate and the advanced adenoma detection rate, and to investigate whether there was a correlation between the quality of preparation and the number of adenomas detected per colonoscopy. We present a retrospective, single-center study of complete screening colonoscopies performed on patients with 50 years old or more, over 18 months (from April 2022 to September 2023), and their respective histological reports. Adequate preparation was considered if all colonic segments scored 2 or more points on the Boston Bowel Preparation Scale (BBPS). Statistical analysis was conducted using SPSS v29.0.

Results

672 total colonoscopies were analyzed. The average age was 64.5 ± 8.0 years, and there was no predominance between genders. BBPS scores ranged from 0 to 9. The majority of patients had adequate bowel preparation (74%, n = 502), with BBPS scores of 6, 7, 8, and 9 in 37.7%, 7.0%, 22.9%, and 7% of cases, respectively. The adenoma detection rate was 41.2% and the detection rate of advanced adenomas was 16.4%. The number of adenomas detected per colonoscopy ranged from 0 to 11 adenomas. No association was found between having adequate preparation and having at least 1 adenoma (p>0.05) or having at least 1 advanced adenoma (p>0.05). There was no statistically significant difference in the average number of adenomas per colonoscopy between patients with and without adequate preparation (p>0.05). There was no correlation between the BBPS score and the number of adenomas per colonoscopy (p>0.05).

Conclusion

The detection rates of adenomas and advanced adenomas were not associated with the adequacy of bowel preparation. No correlation was found between the quality of preparation and the number of adenomas per colonoscopy. Despite the need to repeat another colonoscopy with adequate BBPS for optimal observation of the mucosa, concluding screening procedures in patients with inadequate bowel preparation has still proven to be useful. As long as it is considered safe, endoscopists should be encouraged to conclude all screening procedures.

Introduction

Adequate bowel preparation is paramount for a high-quality screening colonoscopy. Despite the importance of adequate bowel preparation, there is a lack of large studies that associated the degree of bowel preparation with long-term colorectal cancer outcomes in screening patients.

Aims & Methods

In a large population-based screening program database in Austria, quality of bowel preparation was estimated according to the Aronchick scale by the endoscopist (excellent, good, fair, poor and inadequate bowel preparation). We used logistic regression to assess the influence of bowel preparation on the detection of different polyp types and the inter-physician variation in bowel preparation scoring. Time to event analyses were performed to investigate the association of bowel preparation with post-colonoscopy colorectal cancer (PCCRC) death.

Results

335466 colonoscopies between 01/2012 and follow-up until 12/2022 were eligible for the analyses. As compared to excellent bowel preparation, adenoma detection was not significantly lower for good bowel preparation (OR 1.01, 95% CI 0.9971 - 1.0329, p = 0.1023), however, adenoma detection was significantly lower in fair bowel preparation (OR 0.97, 95% CI 0.9408 - 0.9939, p = 0.0166). Individuals who had fair or lower bowel preparation at screening colonoscopy had significantly higher hazards for PCCRC death (HR for fair bowel preparation 2.56, 95% CI 1.67 - 3.94, p <0.001).

Conclusion

Fair bowel preparation on the Aronchick scale was not only associated with a lower adenoma detection probability, but also with increased risk for PCCRC death. Efforts should be made to increase bowel cleansing above fair scores.

Disclosure

MT had advised for Abbvie, Albireo, BiomX, Boehringer Ingelheim, Falk, Gilead, Genfit, Hightide, Intercept, Jannsen, MSD, Novartis, Phenex, Pliant, Regulus, Siemens, Shire, has received grants / research support from Albireo, Alnylam, Cymabay, Falk Pharma, Gilead, Intercept, MSD, Takeda, UltraGenyx, had received speakersfees form BMS, Falk Foundation, Gilead, Intercept, Madrigal, MSD, Roche, has received travel grants from AbbVie, Falk Foundation, Gilead, Intercept, Janssen, Roche, the Medical Universities of Graz and Vienna have filed patents on medical use of norUDCA and is listed as co-inventor.
All other authors have no conflict of interest to declare.

Introduction

Screening colonoscopy reduces colorectal cancer (CRC) mortality. However, several studies have reported a lower participation rate of colonoscopy. Now it is important to provide less invasive test for CRC screening.
AminoIndex® Cancer Risk Screening (AICS®) is an examination that measures plasma amino acid concentrations and estimates the risk of existing CRC based on the difference in amino acid balance in patients with CRC and healthy individuals. AICS is calculated from 0.0 to 10.0 with the higher value indicating a higher the risk of existing CRC.
We aimed to conduct a prospective cohort study to evaluate the accuracy of AICS® in detecting the risk probability for early colorectal lesions, such as advanced adenoma (AA), intramucosal neoplasia (Tis), or T1 CRC.

Aims & Methods

Consecutive patients who underwent colonoscopy between 06/02/2017 and 31/03/2021at the National Cancer Center Central Hospital and endoscopically diagnosed adenoma larger than 20 mm, intramucosal neoplasia (Tis), or submucosal invasive carcinoma (T1) were included as a selection criterion. Patients with endoscopically suspected intramucosal neoplasia or high-grade dysplasia by preoperative colonoscopy, but finally diagnosed with adenoma were also included in the study. We excluded the following patients; 1) patients with polyposis such as familial colorectal adenomatosis or inflammatory bowel disease, 2) patients with concurrent cancer of other organs, 3) patients with obvious bleeding, 4) patients with severe defecation disorder, and 5) patients with stenosis of colon or intestine.
We measured plasma amino acid concentrations calculated the AICS score. FIT was also measured at the same time. The lesions were endoscopically resected using EMR or ESD technique. The sensitivity of AICS, FIT, and the combination of FIT and AICS were examined according to the pathological diagnosis.

Results

Two hundred and seventeen patients were included in the primary analysis, and 208 patients excluding 9 patients who did not perform FIT were included in the secondary analysis.
The median age of the 217 patients was 71 years old (range: 32- 91). The mean lesion size was 28.9 mm±12.9. Prevalence of AA, Tis, T1, and advanced lesion was, 63, 118, 30, and 6, respectively. Six lesions were suspected to be T1 carcinoma on preoperative endoscopy, following pathological examination revealed advanced cancer after endoscopic resection. The sensitivity of AICS for the advanced neoplasia (AN), AA, intramucosal neoplasia (Tis), submucosal invasive carcinoma, and advanced CRC was 28.1％, 30.9%, 25.4%, 23.3%, and 33.3%, respectively.
In the secondary endpoint, the sensitivity of FIT for AN, AA, intramucosal neoplasia (Tis), submucosal invasive carcinoma, and advanced CRC was 47.0%, 35.3%, 49.1%, 46.7%, and 100%, respectively. The sensitivity of the combination of FIT and AICS for AN, AA, intramucosal neoplasia (Tis), submucosal invasive carcinoma, and advanced CRC was 61.1％, 52.9%, 64.0%, 60.0%, 100%, respectively.

Conclusion

Although it was a reasonable value compared to the development data, AICS® has insufficient sensitivity for lesions requiring endoscopic intervention. It could be clinically applicable as a minimally invasive examination to stratify the risk of existing CRC in combination with FIT for colorectal screening.

Disclosure

The primary investigator (Hiroyuki Takamaru) had received research funding from Ajinomoto Co. Ltd.

Introduction

Adequate bowel preparation is a well-established quality parameter for screening colonoscopies correlating with another important quality parameter of colonoscopy, the adenoma detection rate (ADR). Additional parameters like sessile serrated adenoma detection rate (SSADR) and advanced adenoma detection rate (AADR) have been discussed as additional quality indicators without a clear correlation with bowel preparation quality.

Aims & Methods

In this study we aimed to compare ADR, AADR and SSADR between different bowel preparation qualities in a large real-world colorectal cancer screening cohort.
Colonoscopy data from the Austrian national colorectal cancer screening program collected between 2012 and 2022 were analysed. Bowel preparation was categorized into five different groups (excellent, good, fair, poor and insufficient) according to the Aronchik Scale. ADR, SSADR and AADR were calculated for each group.

Results

A total of 375,352 colonoscopies (48.2 % in men) performed by 404 endoscopists working in hospitals and private practices were included in the final analysis. The cecal intubation rate (CIR) was ≥90% in adequate bowel preparations and also in insufficient bowel preparations. However, CIR in poor bowel preparations was only 57.3%. The most common reasons for incomplete colonoscopy in these patients, as stated by the treating endoscopist, was extensive fecal contamination in 93.2% of cases. Mean overall ADR, SSADR and AADR were 23.8%, 8.5% and 4.2%, respectively. ADR/SSADR/AADR in excellent, good, fair, poor and insufficient bowel preparations were 26.9%/10.1%/3.1%, 27.2/8.5%/3.3%, 27.2/8.5%/3.3%, 15.3/9.2%/7.3% and 22,5/6.4%/4%, respectively. In patients with insufficient bowel preparation exclusively in the right colon, ADR/SSADR and AADR were 25.9%/4.9% and 3.1%.

Conclusion

The recommended international standard of an ADR ≥25% was achieved in patients with adequate (excellent, good and fair) bowel preparations. Interestingly, the CIR in poor bowel preparations was very low (57.3%) even compared with the CIR in insufficient bowel preparations (89.9%). Further, detection of advanced adenomas was not inferior in the inadequate bowel preparation groups, suggesting that these types of adenomas might be also seen without an adequate bowel preparation.

Introduction

Inadequate bowel preparation is linked to reduced adenoma detection rates (ADR), and establishing a threshold for bowel preparation below which colonoscopies should be repeated early is crucial for patient outcomes. However, manual bowel cleansing efficacy evaluation relies on the clinical observer's experience, resulting in subjectivity with clinical and economic implications. The Boston Bowel Preparation Scale (BBPS) is the most validated scoring scale. Our group previously constructed an AI-based bowel preparation assessment model to calculate e-BBPS scores.

Aims & Methods

This prospective, single-center study was conducted at the Eighth Affiliated Hospital, Sun Yat-sen University in China from October 2021 to November 2022. Eligible patients underwent screening colonoscopy by one of three study endoscopists. The AI calculated the e-BBPS score during colonoscope withdrawal. The endoscopist assessed bowel preparation adequacy using BBPS after the colonoscopy. If both BBPS and e-BBPS deemed bowel preparation adequate, the same endoscopist performed a second colonoscopy. If either considered it inadequate, the patient underwent bowel re-cleansing before the second colonoscopy. Video recordings were evaluated for bowel preparation using BBPS by five independent endoscopist raters.

Results

From October 8, 2021, to November 9, 2022, a total of 393 patients were included for analysis. In patients with unqualified-AI, the >5mm AMR was significantly higher than in patients with qualified-AI (p=0.0056, OR 0.2734, 95% CI 0.1139, 0.6565), as were the AMR <0.001 (p=0.2532, 95% CI 0.1583, 0.4052), diminutive AMR (p<0.001, OR 0.2160, 95% CI 0.1206, 0.3867), >5mm PMR (p=0.0152, OR 0.4335, 95% CI 0.2288, 0.8213), and PMR (p <0.001, OR 0.4532, 95% CI 0.3447, 0.5958). No significant differences were observed in the overall >5mm ADR, ADR, >5mm PDR, and PDR. In the first pass, no statistical differences were found in ADR between the qualified-AI and unqualified-AI groups, though there was a trend toward a higher ADR in the qualified-AI group. In the second pass, patients in the qualified-AI group achieved significantly lower >5mm ADR, ADR, diminutive ADR, advanced ADR, >5mm PDR, and PDR compared to those in the unqualified-AI group.
Cohen's kappa analysis revealed high agreement between expert raters, clinical scoring, and e-BBPS (ranging from 0.7791 to 0.8322). However, the agreement between general endoscopists and other raters was only low to moderate (0.2937 to 0.6071). Fleiss' kappa also indicated that the overall agreement among all raters was only 0.575 (p < 0.001, 95% CI 0.574, 0.575), while the Fleiss' kappa for Expert and Clinical scoring, as well as Expert, Clinical scoring, and e-BBPS were 0.809 (p < 0.001, 95% CI 0.807, 0.810) and 0.800 (p < 0.001, 95% CI 0.799, 0.801), respectively.

Conclusion

This study validates the e-BBPS bowel preparation evaluation threshold, confirming that patients with a score of ≤3 have adequate bowel preparation for detecting >5mm adenomatous polyps, while those with a score of >3 require repeat bowel preparation. This conclusion supports the implementation and promotion of fully automated bowel preparation assessment systems, which may improve the objectivity of bowel preparation evaluation and standardize clinical practice for screening colonoscopies in the future.

Introduction

Colonic diverticular bleeding (CDB) is the most common cause of acute lower gastrointestinal bleeding (ALGIB). In a recent Japanese multicenter retrospective cohort study, 63.6% of patients with ALGIB were ultimately diagnosed with CDB [1]. It has also been reported that CDB in ALGIB is reportedly more severe than in other entities [2, 3]. However, few reports have demonstrated the efficacy and safety of bowel preparation for patients undergoing urgent colonoscopy.

Aims & Methods

We aim to clarify choice a of bowel preparation for urgent colonoscopy in patients with colonic diverticular bleeding. In a multicenter retrospective cohort study at 10 institutions, we analyzed the endoscopic findings and clinical course of patients diagnosed with CDB who underwent urgent colonoscopy within 24 hours after admission. Bowel preparation consisted of oral consumption of 1 to 2 L of polyethylene glycol lavage (PEL); enemas were not used. We compared those CDB patients who underwent PEL (PEL group) with a control group who did not undergo PEL (non-PEL group) before and after propensity score matching. For the matching, we selected variables known at the time of hospital admission (i.e. age, sex, comorbidities, medications, performance status, and laboratory data). The primary endpoint of the study was length of hospital stay, and secondary endpoints included blood transfusion requirements, rebleeding rates, endoscopic findings, and complications.

Results

242 patients were enrolled in this study. The median age was 76 years, and 60.7% of patients were men (n = 147). Approximately half of the patients underwent bowel preparation with PEL prior to urgent colonoscopy (n = 129). We compared with clinical findings between the PEL and non-PEL groups. The length of hospital stay was shorter in the PEL group (8.0 ± 5.1 days vs 10.9 ± 5.8 days; mean ± SD; P < 0.001). Further, the PEL group was significantly younger (72.2 ± 12.1 vs 75.4 ± 13.1; mean ± SD; P = 0.036), had fewer patients with hypertension (62.0% vs 75.2%; P = 0.027) and malignant neoplasm (1.6% vs 10.6%; P = 0.002), and had better performance statuses (86.1% vs 76.1%; P = 0.047). Patients in the PEL group received fewer blood transfusions (25.6% vs 44.3%; P = 0.002), had a higher rate of cecal completion (88.3% vs 49.6%; P < 0.001), and shorter endoscopic observation times (20.8 ± 16.2 min vs 29.9 ± 24.8 min; mean ± SD; P = 0.006). After propensity score matching, there were 91 patients each in PEL group and in non-PEL group. PEL group had a significantly shorter hospital stay (7.9 ± 4.6 days vs 10.7 ± 5.8 days; mean ± SD; P < 0.001), a higher cecum completion rate (87.8% vs 48.3%; P < 0.001), and a shorter endoscopic observation time (20.7 ± 16.8 min vs 28.9 ± 24.1 min; mean ± SD; P = 0.031) than non-PEL group. There were no significant differences in blood transfusion requirements, rebleeding rates, identification of SRH, need for endoscopic hemostatic treatment, or complication rates.

Conclusion

In patients with CDB, urgent colonoscopy under PEL resulted in shorter hospital stays, higher cecal completion rates, and shorter endoscopic observation time in urgent colonoscopy. The safety of urgent colonoscopy with PEL was comparable to colonoscopy without PEL. These results suggest that PEL is preferrable for urgent colonoscopy in patients with CDB.

References

1. Nagata N, Kobayashi K, Yamauchi A, et al. Identifying bleeding etiologies by endoscopy affected outcomes in 10,342 cases with hematochezia: CODE BLUE-J study. Am J Gastroenterol 2021; 116: 2222-2234.
2. Aoki T, Nagata N, Shimbo T, et al. Development and validation of a risk scoring system for severe acute lower gastrointestinal bleeding. Clin Gastroenterol Hepatol 2016; 14: 1562-1570.e2.
3. Xavier SA, Machado FJ, Magalhães JT, et al. Acute lower gastrointestinal bleeding: are STRATE and BLEED scores valid in clinical practice? Colorectal Dis 2019; 21: 357-364.