Introduction

The detection and resection of adenomatous polyps during colonoscopy has been shown to be the most effective way to decrease the incidence of colorectal cancer and associated mortality ^{1, 2}, with adenoma detection rate (ADR) being a key quality performance indicator. While higher ADR is associated with lower post-colonoscopy colorectal cancer (PCCRC) rates, the latter varies significantly across the UKand the true ‘baseline’ ADR is unknown ^3,4. Meeting the rising demand for high quality colonoscopy is a significant challenge.
The use of computer assisted detection (CADe) is associated with a significant improvement in ADR across multiple clinical trials^{5, 6}, but real-world performance data is lacking.
We sought to evaluate effect on adenoma detection of implementing CADe in a ‘real-world’ setting, in the largest such study to date.

Aims & Methods

This was a randomised, stepped-wedge, open-label trial, using the GI Genius™ (GIG) module, powered to measure the site effect of CADe. A mix of District General Hospitals (DGH) and Teaching Hospitals (TH) were included, with an emphasis on ‘non-expert’ colonoscopists (lifetime colonoscopy <2000 at study start). ‘Expert’ colonoscopists were eligible (lifetime colonoscopy >2000 and ADR>40%).
Data collection was divided into three, 3-month phases: phase 1, baseline data collection with no CADe; phase 2, the intervention phase, where GIG-CADe was active; phase 3 where GIG-CADe was removed. The endoscopists and procedural information were recorded during the three phases. ADR across all three phases was analysed and compared.
Data will be forthcoming from 29 hospitals (England, Scotland, and Wales), n=124 colonoscopists and n>5000 patients, but we report herein results from the first 8 sites to complete the trial.
All patients undergoing routine (non-BCSP) colonoscopy were eligible, but those having colonoscopy for polyp or IBD surveillance were excluded. The study design was as close to real world practice as possible, with no other changes in procedure or technique.

Results

Across the 8 sites involved (2 TH), there were 34 endoscopists (64.7% non-expert vs 35.3% expert) and 1418 patients (56.43±16.9 years; 49.5% female) eligible for analysis. Comparative results (univariate analysis) through the three study phases are reported in table 1. When adjusted for bowel preparation and the endoscopists’ experience, there was a 9.53% increase in ADR in the CADe group (r² = 0.159; p = 0.0142).
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Conclusion

NAIAD is the largest trial of CADe to date and, in this interim analysis, establishes a baseline UK ADR of approximately 27.0%. The use of GIG-CADe is associated with a significant increase in ADR, but this returns to baseline when the device is switched off. Further analysis of our result will inform the implementation of CADe in routine practice.

References

Reference:
1) M.F. Kaminski, J. Regula, E. Kraszewska, et al. Quality indicators for colonoscopy and the risk of interval cancer N Engl J Med, 362 (2010), pp. 1795-1803
2) M.F. Kaminski, P. Wieszczy, M. Rupinski, et al. Increased rate of adenoma detection associates with reduced risk of colorectal cancer and death Gastroenterology, 153 (2017), pp. 98-105
3) Burr NE, Derbyshire E, Taylor J, Whalley S, Subramanian V, Finan P J et al. Variation in post-colonoscopy colorectal cancer across colonoscopy providers in English National Health Service: population based cohort study BMJ 2019; 367: l6090 doi:10.1136/bmj.l6090
4) D.A. Corley, C.D. Jensen, A.R. Marks, et al. Adenoma detection rate and risk of colorectal cancer and death N Engl J Med, 370 (2014), pp. 1298-1306
5) Shaukat A, Lichtenstein DR, Somers SC, Chung DC, et al Computer-Aided Detection Improves Adenomas per Colonoscopy for Screening and Surveillance Colonoscopy: A Randomized Trial. Gastroenterology. 2022 Sep;163(3):732-741. doi: 10.1053/j.gastro.2022.05.028. Epub 2022 May 25. PMID: 35643173.
6) Wang, Pu, et al. "Effect of a deep-learning computer-aided detection system on adenoma detection during colonoscopy (CADe-DB trial): a double-blind randomised study." The lancet Gastroenterology & hepatology 5.4 (2020): 343-351.

Introduction

Early detection of neoplasia in Barrett’s Esophagus (BE) remains challenging. Although computer-aided detection (CADe) systems are increasingly available to support endoscopists, successful CADe implementation largely depends on the quality of endoscopic images, which can vary significantly in clinical practice. This study introduces an innovative computer-aided quality (CAQ) system designed for BE endoscopy, capable of assessing various image quality parameters, providing real-time feedback to the endoscopist, and operating in conjunction with an established CADe system.

Aims & Methods

The CAQ system was trained on 4,926 images from 243 BE patients to assess both objective (e.g., blurriness, illumination, and specular reflections) and subjective (i.e., mucosal cleanliness and esophageal expansion) image quality factors. The system is able to provide real-time feedback on these quality parameters to the endoscopist. Additionally, it is configured to function as a preprocessing filter for a previously developed CADe system, automatically excluding lower-quality images. To validate the CAQ system’s performance as a standalone tool, we constructed an endoscopic image quality test set, which included 647 images from 51 non-dysplastic BE patients across eight hospitals. These images were annotated for objective (e.g. motion blur, lighting) and subjective (i.e. esophageal expansion, mucosal cleanliness) image quality parameters by two experts. Additionally, to evaluate the CAQ system’s role as a preprocessing step for an established CADe system, we created the Barrett CADe test set, containing 956 frames from 62 neoplastic BE patients and 557 frames from 35 non-dysplastic BE patients from 12 Barrett referral centers. Outcome measures included agreement scores with experts for standalone image quality assessment and sensitivity, specificity, and Area-under-the-Curve (AUC) for BE neoplasia detection.

Results

As a stand-alone system, the CAQ system achieved Cohen’s Kappa scores for agreement with expert annotators of 0.73, 0.91, and 0.89 for objective image quality parameters, mucosal cleanliness, and esophageal expansion, respectively—comparable to inter-annotator scores of 0.73, 0.93, and 0.83. When used as a preprocessing filter for the CADe system, the CAQ system improved the CADe's sensitivity from 82% to 90% and the AUC from 87% to 91%, while specificity remained stable at 75% (Table 1).

Table 1. Performance of the CADe system for Barrett’s neoplasia detection with and without the CAQ system.

Conclusion

This study introduces the first CAQ system specifically aimed at automated quality control in BE endoscopy. As a standalone tool, the system effectively distinguishes poorly from well-visualized mucosa. When combined with an established CADe system, it enhances detection rates for neoplasia, highlighting its potential to improve diagnostic accuracy in BE surveillance.

Introduction

Endoscopic retrograde cholangiopancreatography (ERCP) is a key procedure in managing biliary and pancreatic disorders. In cases of difficult cannulation (DC), when standard cannulation techniques (SCT) fail, precut sphincterotomy (PS) may be used as an alternative technique, often by experienced endoscopists. PS has been shown to improve cannulation success rates, but its use has been associated with an increased risk of adverse events, including post-ERCP pancreatitis (PEP), perforation, and bleeding. Despite this it is argued that it might be safer to proceed with PS early rather than to traumatise the papilla with continuous attempts with SCT. DC is defined as cannulation taking more than 5 minutes, more than 5 attempts or accidently entering the pancreatic duct with a guidewire more than once and is known to be associated with more complications than non-DC. The aim of this study was to compare outcomes of PS versus SCT in cases of DC, regarding complication rates and successful cannulation.

Aims & Methods

Data were retrieved from the Swedish National Register for Gallstone surgery and ERCP, GallRiks from September 2016 to December 2023. A total of 30,561 ERCPs, performed as index ERCPs without rendezvous technique, were identified and cross-checked. Logistic regression analyses were conducted, adjusting for endoscopist and clinic volume using generalized estimating equations.

Results

Altogether 9,909 procedures were classified as DC among which 3,005 (30%) were performed with PS, compared to 434 (2%) of 20,218 in the non-DC group. In DC the rate of pancreatitis was 9.4%, cholangitis 2.3%, bleeding 1.4%, bile leakage 1.9% and perforation 0.7%. PS was not associated with increased risk of procedure related complications in DC. The rate of successful cannulation in DC was 87.9% when SCT were used and 70.4% when PS was performed.

Conclusion

PS is a safe technique in ERCP when cannulation is difficult and is not associated with an increased risk of complications compared to SCT.

Introduction

Endoscopic intermuscular dissection (EID) was recently introduced as a novel resection technique for deep submucosal invasive rectal cancer (D-SMIC)¹. While short-term outcomes are promising, intermediate- and long-term oncological safety has not yet been established. Therefore, we aimed to evaluate the 3-year oncological outcomes of EID for suspected rectal D-SMIC.

Aims & Methods

In this prospective cohort study, data of consecutive patients treated with EID for suspected rectal D-SMIC at two academic hospitals in the Netherlands between 2018 and 2022 were analyzed. Superficial submucosal invasive cancer (S-SMIC) was defined as Sm1 and D-SMIC as Sm2-3. Tumors were considered high-risk if they exhibited at least one of the following histological risk factors: high-grade tumor differentiation (G3), lymphovascular invasion, tumor budding grade 2-3, R1/Rx resection margins (<0.1 mm), or ≥pT2 invasion. Patients with D-SMIC or ≥pT2 invasion who did not undergo further treatment after EID, either due to the absence of additional risk factors or based on patient preference, underwent close surveillance. This surveillance involved biannual MRI and endoscopic scar inspection for 2 years, followed by annual MRI and endoscopy for 3 years. A complete colonoscopy was performed after 1 and 4 years. CEA blood levels were measured every six months for 5 years. Study outcomes included the 3-year locoregional recurrence rate (LRR), 3-year distant recurrence rate (DRR), 3-year salvageable recurrence rate (SRR) and 3-year rectal preservation rate. The 3-year estimates were calculated using the Kaplan-Meier method. Locoregional recurrence was defined as intramural cancer recurrence and/or mesorectal lymph node metastasis, while distant recurrences referred to other cancer recurrences. Salvageable recurrence was defined as cancer recurrence that could be treated with curative intent. Rectal preservation was defined as the absence of completion total mesorectal excision (TME) following EID or cancer recurrence.

Results

EID was initiated in 188 patients (median age 67 years, 33% female, 85% ASA I-II, median lesion size 25 mm) and successfully completed in 177 (94%). Histology showed non-invasive histology in 20 (11%), S-SMIC in 9 (5%), D-SMIC in 94 (53%) and ≥pT2 in 53 (30%) cases. R0 resection rates within these groups were 100%, 100%, 93% and 58%, respectively. Among the 94 D-SMIC cases, 35 (37%) had no histological risk factors other than deep submucosal invasion. Out of the D-SMIC cases, 72/94 (77%) followed a rectal preserving strategy (64/72 close surveillance and 8/72 adjuvant chemoradiotherapy), while 22/94 (23%) underwent completion TME. The median follow-up period within the D-SMIC group was 30 months (IQR 18-48). At three years, the LRR was 5.9% (95%CI 0.0-11.5%) and the DRR was 1.1% (95%CI 0.0-3.4%). The 3-year SRR was 100% (95%CI 100-100%). One patient (1.1%) died of a non-CRC-related cause. Among the subgroup of 35 D-SMIC cases without additional histological risk factors, all of whom underwent close surveillance following EID, no recurrences occurred within the first three years of follow-up. Beyond this period, one locoregional recurrence (2.9%) occurred at 37 months and one distant recurrence (2.9%) at 51 months, both salvageable. Overall, the 3-year rectal preservation rate among all 188 patients who underwent EID for suspected rectal D-SMIC, was 64.6% (95%CI 58.0-71.9%).

Conclusion

EID for suspected rectal D-SMIC resulted in favorable 3-year rectal preservation rates and demonstrated excellent 3-year oncological outcomes for rectal D-SMIC without additional risk factors.

References

1) Moons LMG, Bastiaansen BAJ, Richir MC, Hazen WL, Tuynman J, Elias SG, Schrauwen RWM, Vleggaar FP, Dekker E, Bos P, Fariña Sarasqueta A, Lacle M, Hompes R, Didden P. Endoscopic intermuscular dissection for deep submucosal invasive cancer in the rectum: a new endoscopic approach. Endoscopy. 2022 Oct;54(10):993-998.