British Society of Gastroenterology/Association of Coloproctologists of Great Britain and Ireland guidelines for the management of large non-pedunculated colorectal polyps

Prevalence of Endoscopically Curable Low-Risk Cancer Among Large (≥20 mm) Nonpedunculated Polyps in the Right Colon

BACKGROUND AND AIMS

Endoscopic submucosal dissection is increasingly promoted for the treatment of all large nonpedunculated colorectal polyps (LNPCPs) to cure potential low-risk cancers (superficial submucosal invasion without additional high-risk histopathologic features). The effect of a universal en bloc strategy on oncologic outcomes for the treatment of LNPCPs in the right colon is unknown. We evaluated this in a large Western population.

METHODS

A prospective cohort of patients referred for endoscopic resection (ER) of LNPCPs was analyzed. Patients found to have cancer after ER and those referred directly to surgery were included. The primary outcome was to determine the proportion of right colon LNPCPs with low-risk cancer.

RESULTS

Over 180 months until June 2023, 3294 sporadic right colon LNPCPs in 2956 patients were referred for ER at 7 sites (median size 30 [interquartile range 22.5-37.5] mm). A total of 63 (2.1%) patients were referred directly to surgery, and cancer was proven in 56 (88.9%). A total of 2851 (96.4%) of 2956 LNPCPs underwent ER (median size 35 [interquartile range 25-45] mm), of which 75 (2.6%) were cancers. The overall prevalence of cancer in the right colon was 4.4% (n = 131 of 2956). Detailed histopathologic analysis was possible in 115 (88%) of 131 cancers (71 after ER, 44 direct to surgery). After excluding missing histopathologic data, 23 (0.78%) of 2940 sporadic right colon LNPCPs were low-risk cancers.

CONCLUSIONS

The proportion of right colon LNPCPs referred for ER containing low-risk cancer amenable to endoscopic cure was <1%, in a large, multicenter Western cohort. A universal endoscopic submucosal dissection strategy for the management of right colon LNPCPs is unlikely to yield improved patient outcomes given the minimal impact on oncologic outcomes.

CLINICALTRIALS

gov, Numbers: NCT01368289, NCT02000141.

Linear-Array Endoscopic Ultrasound and Narrow-Band Imaging Measure the Invasion Depth of Nonpedunculated Rectal Lesions With Comparable Accuracy Based on a Randomized Controlled Trial

INTRODUCTION

Linear-array endoscopic ultrasound (EUS) and narrow-band imaging (NBI) are both used to estimate the invasion depth of nonpedunculated rectal lesions (NPRLs). However, it is unclear which procedure is more accurate. This randomized controlled trial aimed to compare the diagnostic accuracy of linear EUS and NBI for estimating the invasion depth of NPRLs.

METHODS

This study is a single-center, randomized, tandem trial. Eligible patients with NPRLs were randomly assigned to A group (assessment with EUS followed by NBI) or B group (assessment with NBI followed by EUS). The invasion depth of each lesion was independently measured by each procedure and categorized as mucosal to slight submucosal (M-SM s , invasion depth <1,000 μm) or deep submucosal (SM d , invasion depth ≥1,000 μm) invasion, with postoperative pathology as the standard of measurement. The primary outcome was diagnostic accuracy, and secondary outcomes included sensitivity, specificity, and procedure time.

RESULTS

Eighty-six patients with NPRLs were enrolled, and 79 patients were finally analyzed, including 39 cases in the A group and 40 cases in the B group. Comparable diagnostic accuracies were observed between EUS and NBI (96.2% vs 93.7%, P = 0.625). EUS identified lesions with deep submucosal invasion with 81.8% sensitivity while that of NBI was 63.6% ( P = 0.500). The specificity of both EUS and NBI was 98.5%. The procedure time was also similar between EUS and NBI (5.90 ± 3.44 vs 6.4 ± 3.94 minutes, P = 0.450). Furthermore, the combined use of EUS and NBI did not improve diagnostic accuracy compared with EUS or NBI alone (94.9% vs 96.2% vs 93.7%, P = 0.333).

DISCUSSION

Linear EUS and NBI measure the invasion depth of NPRLs with comparable accuracy. The combination of the 2 methods does not improve the diagnostic accuracy. Single NBI should be preferred, considering its simplicity and convenience in clinical practice.

Substratifying the risk of covert malignancy in significant rectal polyps: Outcomes from a specialist multidisciplinary team (MDT)

AIM

A treatment strategy for patients with a significant polyp or early colon cancer (SPECC) of the rectum presents a challenge due to the significant rate of covert malignancy and lack of standardized assessment. For this reason, NICE recommends multidisciplinary meetings to improve outcomes. The primary aim of the present study was to report the performance of our specialist early rectal cancer (SERC) multidisciplinary team (MDT) in correctly substratifying the risk of cancer and to discuss the limitations of staging investigations in those patients with "poor outcomes".

METHOD

This was a retrospective review of patients referred to our SERC MDT from 2014 to 2019. Lesions were assigned by the MDT to three pre-resection categories (low, intermediate, high) according to the risk of covert malignancy. Resection method and final histology were compared to the pre-resection categories.

RESULTS

Of 350 SPECC lesions, 174 were assessed as low-risk, 108 intermediate-risk and 68 high-risk. The cancer incidence was 4.8%, 8.3% and 53%, respectively (15.5% overall). Eight lesions were categorized as low-risk but following piecemeal resection were found to be malignant. Five lesions, three of which were categorized as high-risk, were ultimately benign following conventional surgery. One pT1sm1 cancer, removed by anterior resection, may have been treated by local excision.

CONCLUSION

A total of 83% of malignant polyps were triaged to an en bloc resection technique and surgical resection avoided for nearly all benign lesions. However, 12 patients from this cohort were deemed to have a poor outcome because of miscategorization. Further comparative research is needed to establish the optimum strategy for rectal SPECC lesion assessment.

ORIGINALITY STATEMENT

There is currently no consensus for staging significant polyps of the rectum. This paper reports the effectiveness of a specialist early rectal cancer MDT to correctly risk-stratify significant rectal polyps. It underscores the importance of accurate categorization for treatment decision-making, while acknowledging the limitations of current staging modalities.

Improving the management and outcomes of complex non-pedunculated colorectal polyps at a regional hospital in British Columbia

BACKGROUND

Colorectal cancer arises from precancerous lesions, primarily adenomatous and serrated polyps. Some polyps pose significant technical endoscopic challenges due to their size, location, and/or morphology. A standardized protocol for documentation and management of these polyps can optimize clinical outcomes.

METHODS

A Quality Improvement project compared patients with a complex polyp (non-pedunculated, > 2 cm), for 12 months prior and 12 months after protocol introduction. Documentation and polyp management details were compared pre- and post-implementation using the Chi-square test.

RESULTS

69 patients were diagnosed with complex polyps prior to the protocol introduction and 72 after. 79% (112/141) of patients underwent endoscopic mucosal resections (EMR) locally, and 14.9% (21/141) underwent surgery locally. After protocol introduction, there was significant improvement in documentation of suspicious appearing polyps (21.7% to 47.2%, P = 0.001), luminal circumference (14.5% to 34.7%, P = 0.005), and management plans (87.0% to 97.2%, P = 0.023); other elements of documentation were similar. The number of patients reviewed at multidisciplinary conference (MDC) increased from 1 to 61% (P < 0.005). Patients rebooked in a 1 h endoscopy time slot increased from 19 to 58% (P < 0.005), as did specific consent for EMR from 22 to 57% (P < 0.005). Among patients with polyps 3 cm or greater (23 pre, 36 post), MDC review increased from 4 to 67% (P < 0.005), primary polypectomy decreased from 72 to 23% (P = 0.001), patients rebooked in a double endoscopy slot increased from 33 to 75% (P = 0.005), and specific consent increased from 39 to 75% (P = 0.014). There were less polyp recurrences (12/42 pre and 1/50 post) among the post-protocol cohort (P < 0.001).

CONCLUSIONS

The introduction of a formalized protocol for complex polyp adjudication and management has led to improved documentation, multidisciplinary discussion, and optimal complex polyp management with dedicated time for EMR, particularly for polyps over 3 cm. There is room for improvement, and this can be approached in a collaborative manner.

Clinical utility of colon capsule endoscopy: a moving target?

The purpose of this article is to provide an overview of white light colon capsule endoscopy's current clinical application, concentrating on its most recent developments. Second-generation colon capsule endoscopy (CCE2) is approved by the FDA for use as an adjunctive test in patients with incomplete colonoscopy and within Europe in patients at average risk, those with incomplete colonoscopies or those unwilling to undergo conventional colonoscopies. Since the publication of European Society of GI Endoscopy guidelines on the use of CCE, there has been a significant increase in comparative studies on the diagnostic yield of CCE. This paper discusses CCE2 in further detail. It explains newly developed colon capsule system and the current status on the use of CCE, it also provides a comprehensive summary of systematic reviews on the implementation of CCE in colorectal cancer screening from a methodological perspective. Patients with ulcerative colitis can benefit from CCE2 in terms of assessing mucosal inflammation. As part of this review, performance of CCE2 for assessing disease severity in ulcerative colitis is compared with colonoscopy. Finally, an assessment if CCE can become a cost-effective clinical service overall.

Recommendations for Optimal Endoscopic Localization of Colorectal Neoplasms: A Delphi Consensus of National Experts

BACKGROUND

Colonoscopy is the standard of care for diagnosis and evaluation of colorectal cancers before surgery. However, varied practices and heterogenous documentation affects communication between endoscopists and operating surgeons, hampering surgical planning.

OBJECTIVE

This study aimed to develop recommendations for the use of standardized localization and reporting practices for colorectal lesions identified during lower GI endoscopy.

DESIGN

A systematic review of existing endoscopy guidelines and thorough narrative review of the overall endoscopy literature were performed to identify existing practices recommended globally.

SETTING

An online Delphi process was used to establish consensus recommendations based on a literature review.

PATIENTS

Colorectal surgeons and gastroenterologists from across Canada who had previously demonstrated leadership in endoscopy, managed large endoscopy programs, produced high-impact publications in the field of endoscopy, or participated in the development of endoscopy guidelines were selected to participate.

PRIMARY OUTCOME MEASURES

The primary outcomes measured were colorectal lesion localization and documentation practice recommendations important to planning surgical or advanced endoscopic excisions.

RESULTS

A total of 129 of 197 statements achieved consensus after 3 rounds of voting by 23 experts from across Canada. There was more than 90% participation in each round. Recommendations varied according to lesion location in the cecum, colon, or rectum and whether the referral was planned for surgical or advanced endoscopic resection. Recommendations were provided for appropriate documentation, indications, location, and method of tattoo placement, in addition to photograph and real-time 3-dimensional scope configuration device use.

LIMITATIONS

Because of a paucity of evidence, recommendations are based primarily on expert opinion. There may be bias, as all representatives were based in Canada.

CONCLUSIONS

Best practices to optimize endoscopic lesion localization and communication are not addressed in previous guidelines. This consensus involving national experts in colorectal surgery and gastroenterology provides a framework for efficient and effective colorectal lesion localization. See Video Abstract at http://links.lww.com/DCR/C71 .

RECOMENDACIONES PARA LA LOCALIZACIN ENDOSCPICA PTIMA DE LAS NEOPLASIAS COLORRECTALES UN CONSENSO DELPHI DE EXPERTOS NACIONALES

ANTECEDENTES:La colonoscopia es el estándar de atención para el diagnóstico y la evaluación de los cánceres colorrectales antes de la cirugía. Sin embargo, las prácticas variadas y la documentación heterogénea afectan la comunicación entre los endoscopistas y los cirujanos operadores, lo que dificulta la planificación quirúrgica.OBJETIVO:Este estudio tuvo como objetivo desarrollar recomendaciones para el uso de prácticas estandarizadas de localización y notificación de lesiones colorrectales identificadas en la endoscopia gastrointestinal inferior.DISEÑO:Se realizó una revisión sistemática de las pautas de endoscopia existentes y una revisión narrativa exhaustiva de la literatura general sobre endoscopia para identificar las prácticas existentes recomendadas a nivel mundial. Se utilizó un proceso Delphi en línea para establecer recomendaciones de consenso basadas en la revisión de la literatura.PARTICIPANTES:Se seleccionaron para participar cirujanos colorrectales y gastroenterólogos de todo Canadá que previamente habían demostrado liderazgo en endoscopia, manejado grandes programas de endoscopia, producido publicaciones de alto impacto en el campo de la endoscopia o que habían participado en el desarrollo de pautas de endoscopia.RESULTADOS:Localización de lesiones colorrectales y recomendaciones prácticas de documentación importantes para planificar escisiones quirúrgicas o endoscópicas avanzadas.RESULTADOS:129 de 197 declaraciones lograron consenso después de tres rondas de votación de 23 expertos de todo Canadá. Hubo >90% de participación en cada ronda. Las recomendaciones variaron según la ubicación de la lesión en el ciego, colon o recto, y si se planificó la derivación para resección quirúrgica o endoscópica avanzada. Se proporcionaron recomendaciones para la documentación adecuada, las indicaciones, la ubicación y el método de colocación del tatuaje, además de la fotografía y el uso del dispositivo de configuración del alcance 3D en tiempo real.LIMITACIONES:Debido a la escasez de evidencia, las recomendaciones se basan principalmente en la opinión de expertos. Puede haber sesgo, ya que los representantes tenían su sede en Canadá.CONCLUSIONES:Las mejores prácticas para optimizar la localización y comunicación de lesiones endoscópicas no se abordan en las guías anteriores. Este consenso que involucra a expertos nacionales en cirugía colorrectal y gastroenterología proporciona un marco para la localización eficiente y efectiva de lesiones colorrectales. Consulte Video Resumen en http://links.lww.com/DCR/C71 . (Traducción-Dr. Mauricio Santamaria ).

Usefulness of Contrast-Enhanced Endoscopic Ultrasound (CH-EUS) to Guide the Treatment Choice in Superficial Rectal Lesions: A Case Series

INTRODUCTION

Large rectal lesions can conceal submucosal invasion and cancer nodules. Despite the increasing diffusion of high-definition endoscopes and the importance of an accurate morphological evaluation, a complete assessment in this setting can be challenging. Endoscopic ultrasound (EUS) plays an established role in the locoregional staging of rectal cancer, although this technique has a tendency toward the over-estimation of the loco-regional (T) staging. However, there are still few data on contrast-enhanced endoscopic ultrasound (CH-EUS), especially if this ancillary technique may increase the accuracy for predicting invasive nodules among large rectal lesions.

MATERIAL AND METHODS

Consecutive large (≥20 mm) superficial rectal lesions with high-definition endoscopy, characterized by focal areas suggestive for invasive cancer/2B type according to JNET classification, were considered for additional standardized evaluation via CH-EUS with Sonovue ©.

RESULTS

From 2020 to 2023, we evaluated 12 consecutive superficial rectal lesions with sizes ranging from 20 to 180 mm. This evaluation provided additional elements to support the therapeutic decision made. Lesions were treated with surgical (3/12) or endoscopic treatment (9/12) according to their morphology and CH-EUS evaluation.

CONCLUSION

Contrast-enhanced endoscopic ultrasound can provide an additional evaluation for large and difficult-to-classify rectal lesions. In our experience, CH-EUS staging corresponded to the final pathological stages in 9/12 (75%) lesions, improving the distinction between T1 and T2 lesions. Larger prospective studies and randomized trials should be conducted to support and standardize this approach.

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.

Extended delay in endoscopic mucosal resection is not associated with adverse outcomes: Findings from the COVID-19 pandemic

Background and study aims The aim of this study was to investigate the impact of delayed endoscopic mucosal resection (EMR) of colorectal polyps on health outcomes.

Patients and methods A bidirectional cohort study was completed. A baseline group consisting of all EMRs performed within a 15-month period before a province-wide, government-mandated cessation of EMR procedures due to the global pandemic was compared to EMRs impacted by the shutdown, defined as the COVID-19-delayed group. The primary outcome was the incidence of malignant polyps. Secondary outcomes included technical success, polyp recurrence at follow-up colonoscopy, advanced polyp histology, probability of meeting endoscopic criteria for adequate resection for malignant polyps, metastatic colorectal cancer, and complications.

Results A total of 268 EMR procedures were included in the study cohort, of which 208 formed the baseline group and 60 were in the COVID-19-delayed group. The median (IQR) patient age was 72 (13.0) and 113 (41.2 %) were females. The median (IQR) wait time was 92 days (87.8) in the baseline group and 191 days (127.8) in the COVID-19-delayed group (P < 0.001). Overall, there were no significant differences in the incidence of malignant polyps, technical success, polyp recurrence on follow-up colonoscopy, advanced polyp histology, adequate endoscopic resection for malignant polyps, metastatic colorectal cancer, or complications between the two groups (P > 0.05 for all outcomes).

Conclusions A longer wait time for EMR of colorectal polyps, increasing from a median of 92 to 191 days, was not associated with worse outcomes.

Planning management for complex colorectal polyps: a qualitative assessment of factors influencing decision-making among colonoscopists

OBJECTIVE

Endoscopic therapy is the recommended primary treatment for most complex colorectal polyps, but high colonic resection rates are reported. The aim of this qualitative study was to understand and compare between specialities, the clinical and non-clinical factors influencing decision making when planning management.

DESIGN

Semi-structured interviews were performed among colonoscopists across the UK. Interviews were conducted virtually and transcribed verbatim. Complex polyps were defined as lesions requiring further management planning rather than those treatable at the time of endoscopy. A thematic analysis was performed. Findings were coded to identify themes and reported narratively.

RESULTS

Twenty colonoscopists were interviewed. Four major themes were identified including gathering information regarding the patient and their polyp, aids to decision making, barriers in achieving optimal management and improving services. Participants advocated endoscopic management where possible. Factors such as younger age, suspicion of malignancy, right colon or difficult polyp location lead towards surgical intervention and were similar between surgical and medical specialties. Availability of expertise, timely endoscopy and challenges in referral pathways were reported barriers to optimal management. Experiences of team decision-making strategies were positive and advocated in improving complex polyp management. Recommendations based on these findings to improve complex polyp management are provided.

CONCLUSION

The increasing recognition of complex colorectal polyps requires consistency in decision making and access to a full range of treatment options. Colonoscopists advocated the availability of clinical expertise, timely treatment and education in avoiding surgical intervention and providing good patient outcomes. Team decision-making strategies for complex polyps may provide an opportunity to coordinate and improve these issues.

Outcomes of complex colorectal polyps managed by multi-disciplinary team strategies-a multi-centre observational study

PURPOSE

Team management strategies for complex colorectal polyps are recommended by professional guidelines. Multi-disciplinary meetings are used across the UK with limited information regarding their impact. The aim of this multi-centre observational study was to assess procedures and outcomes of patients managed using these approaches.

METHOD

This was a retrospective, observational study of patients managed by six UK sites. Information was collected regarding procedures and outcomes including length of stay, adverse events, readmissions and cancers.

RESULTS

Two thousand one hundred ninety-two complex polyps in 2109 patients were analysed with increasing referrals annually. Most presented symptomatically and the mean polyp size was 32.1 mm. Primary interventions included endoscopic therapy (75.6%), conservative management (8.3%), colonic resection (8.1%), trans-anal surgery (6.8%) or combined procedures (1.1%). The number of primary colonic resections decreased over the study period without a reciprocal increase in secondary procedures or recurrence. Secondary procedures were required in 7.8%. The median length of stay for endoscopic procedures was 0 days with 77.5% completed as day cases. Median length of stay was 5 days for colonic resections. Overall adverse event and 30-day readmission rates were 9.0% and 3.3% respectively. Malignancy was identified in 8.8%. Benign polyp recurrence occurred in 13.1% with a median follow up of 30.4 months. Screening detected lesions were more likely to undergo bowel resection. Colonic resection was associated with longer stays, higher adverse events and more cancers on final histology.

CONCLUSION

Multi-disciplinary team management of complex polyps is safe and effective. Standardisation of organisation and quality monitoring is needed to continue positive effects on outcomes and services.

JAG consensus statements for training and certification in flexible sigmoidoscopy

Introduction

Joint Advisory Group (JAG) certification in endoscopy is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update standards for training and certification in flexible sigmoidoscopy (FS).

Methods

A modified Delphi process was conducted between 2019 and 2020 with multisociety representation from experts and trainees. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on FS training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer-reviewed by national stakeholders for incorporation into the JAG FS certification pathway.

Results

In total, 41 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (17), assessment of competence (7) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (A) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, rectal retroversion >90%, polyp retrieval rate >90%, patient comfort <10% with moderate-severe discomfort); (B) minimum procedure count ≥175; (C) performing 15+ procedures over the preceding 3 months; (D) attendance of the JAG Basic Skills in Lower gastrointestinal Endoscopy course; (E) satisfying requirements for formative direct observation of procedural skill (DOPS) and direct observation of polypectomy skill (SMSA level 1); (F) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool and (G) successful performance in summative DOPS.

Conclusion

The UK standards for training and certification in FS have been updated to support training, uphold standards in FS and polypectomy, and provide support to the newly independent practitioner.

JAG consensus statements for training and certification in colonoscopy

Introduction

In the UK, endoscopy certification is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update and develop standards and recommendations for colonoscopy training and certification.

Methods

Under the oversight of the Joint Advisory Group (JAG), a modified Delphi process was conducted between 2019 and 2020 with multisociety expert representation. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on colonoscopy training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer reviewed by JAG and relevant stakeholders for incorporation into the updated colonoscopy certification pathway.

Results

In total, 45 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (20), assessment of competence (8) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (1) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, unassisted caecal intubation rate >90%, rectal retroversion >90%, polyp detection rate >15%+, polyp retrieval rate >90%, patient comfort <10% with moderate–severe discomfort); (2) minimum procedure count 280+; (3) performing 15+ procedures over the preceding 3 months; (4) attendance of the JAG Basic Skills in Colonoscopy course; (5) terminal ileal intubation rates of 60%+ in inflammatory bowel disease; (6) satisfying requirements for formative direct observation of procedure skills (DOPS) and direct observation of polypectomy skills (Size, Morphology, Site, Access (SMSA) level 2); (7) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool; (8) successful performance in summative DOPS.

Conclusion

The UK standards for training and certification in colonoscopy have been updated, culminating in a single-stage certification process with emphasis on polypectomy competency (SMSA Level 2+). These standards are intended to support training, improve standards of colonoscopy and polypectomy, and provide support to the newly independent practitioner.

How to avoid overtreatment of benign colorectal lesions: Rationale for an evidence-based management

Implementing population-based screening programs for colorectal cancer has led to an increase in the detection of large but benign histological lesions. Currently, endoscopic mucosal resection can be considered the standard technique for the removal of benign lesions of the colon due to its excellent safety profile and good clinical results. However, several studies from different geographic areas agree that many benign colon lesions are still referred for surgery. Moreover, the referral rate to surgery is not decreasing over the years, despite the theoretical improvement of endoscopic resection techniques. This article will review the leading causes for benign colorectal lesions to be referred for surgery and the influence of the endoscopist experience on the referral rate. It will also describe how to categorize a polyp as complex for resection and consider an endoscopist as an expert in endoscopic resection. And finally, we will propose a framework for the accurate and evidence-based treatment of complex benign colorectal lesions.

Predictors for malignant potential and deep submucosal invasion in colorectal laterally spreading tumors

BACKGROUND

Colorectal laterally spreading tumors (LSTs) with malignant potential require en bloc resection by endoscopic submucosal dissection (ESD), but lesions with deep submucosal invasion (SMI) are endoscopically unresectable.

AIM

To investigate the factors associated with high-grade dysplasia (HGD)/carcinoma and deep SMI in colorectal LSTs.

METHODS

The endoscopic and histological results of consecutive patients who underwent ESD for colorectal LSTs in our hospital from June 2013 to March 2019 were retrospectively analyzed. The characteristics of LST subtypes were compared. Risk factors for HGD/carcinoma and deep SMI (invasion depth ≥ 1000 μm) were determined using multivariate logistic regression.

RESULTS

A total of 323 patients with 341 colorectal LSTs were enrolled. Among the four subtypes, non-granular pseudodepressed (NG-PD) LSTs (85.5%) had the highest rate of HGD/carcinoma, followed by the granular nodular mixed (G-NM) (77.0%), granular homogenous (29.5%), and non-granular flat elevated (24.2%) subtypes. Deep SMI occurred commonly in NG-PD LSTs (12.9%). In the adjusted multivariate analysis, NG-PD [odds ratio (OR) = 16.8, P < 0.001) and G-NM (OR = 7.8, P < 0.001) subtypes, size ≥ 2 cm (OR = 2.2, P = 0.005), and positive non-lifting sign (OR = 3.3, P = 0.024) were independently associated with HGD/carcinoma. The NG-PD subtype (OR = 13.3, P < 0.001) and rectosigmoid location (OR = 8.7, P = 0.007) were independent risk factors for deep SMI.

CONCLUSION

Because of their increased risk for malignancy, it is highly recommended that NG-PD and G-NM LSTs are removed en bloc through ESD. Given their substantial risk for deep SMI, surgery needs to be considered for NG-PD LSTs located in the rectosigmoid, especially those with positive non-lifting signs.

Setting up a regional expert panel for complex colorectal polyps

BACKGROUND AND AIMS

Advanced endoscopic resection techniques for complex colorectal polyps have evolved significantly over the past decade, leading to a management shift from surgical to endoscopic resection as the preferred treatment. However, in practice, interhospital consultation and appropriate referral management remain challenging, leading to unnecessary surgical resections. To support regional care for patients with complex colorectal polyps, facilitate peer consultations, and lower thresholds for referrals, an expert panel consultation platform was initiated in the northwestern region of the Netherlands.

METHODS

We initiated a regional expert panel in the northwestern region of the Netherlands for patients with complex colorectal polyps and studied the implementation, adaption, and clinical impact. All panel consultations between June 2019 and May 2021 were retrospectively analyzed, and user satisfaction among panel members was evaluated.

RESULTS

Eighty-eight patients with complex colorectal polyps from 11 of 15 participating centers (73.3%) were discussed in our panel. The most common reason for panel consultation was suspicion of invasive cancer in 36.4% (n = 32). After panel consultation, 43.2% of the consulting endoscopists (n = 38) changed their initial treatment strategy, and in 63.6% (n = 56) patients were referred to another endoscopy center. Of 26 cases submitted with a primary proposal for surgical treatment, surgery was avoided in 7 (26.9%). User satisfaction was rated high in most participating centers (91.7%).

CONCLUSIONS

Our study shows that implementation of and consultation with a regional expert panel can be a valuable tool for endoscopists to guide and optimize treatment of complex colorectal polyps and facilitate interhospital referrals in a regional network.

Performance measures for the SACRED team-centered approach to advanced gastrointestinal endoscopy: European Society of Gastrointestinal Endoscopy (ESGE) Quality Improvement Initiative

The European Society of Gastrointestinal Endoscopy and United European Gastroenterology have defined performance measures for upper and lower gastrointestinal, pancreaticobiliary, and small-bowel endoscopy. Quality indicators to guide endoscopists in the growing field of advanced endoscopy are also underway. We propose that equal attention is given to developing the entire advanced endoscopy team and not the individual endoscopist alone.We suggest that the practice of teams intending to deliver high quality advanced endoscopy is underpinned by six crucial principles concerning: selection, acceptance, complications, reconnaissance, envelopment, and documentation (SACRED).

[Treatment of the colorectal polyps]

Bevezetés és célkitűzés

A colorectális polypok komplex ellátása komoly kihívást jelent nemcsak az endoszkópos szakemberek, hanem a sebészek számára is.

Anyag és módszerek

A colorectális polypok sebészeti ellátását 2014-ig a hagyományos sebészi per anum polypectomiák vagy lokális excisók (LE) jelentették a szegedi Sebészeti Klinikán. Ezen hagyományos transanális műtéti technikák hátrányai mindenki számára jól ismertek: magas resectiós szél pozitivitás arány, alacsony „en bloc” resectiós arány, valamint a magasabban, 5 cm felett elhelyezkedő léziók eltávolításának nehézségei stb. Mindezek alapján felmerült az igény, hogy a transanális műtétek technikai fejlődésével lépést tartva, nemcsak új műtéti módszert (TAMIS, transanális minimálisan invazív sebészet) vezessünk be, hanem a már jól ismert, de még nem alkalmazott műtéti technikát, úgymint a TEM (transanális endoszkópos mikrosebészet) is alkalmazni kezdjük. Klinikánkon az új sebészi módszerek bevezetése mellett fontosnak tartottuk a sebészi gasztroenterológia, azon belül is a sebészi endoszkópia humán és tárgyi feltételeinek fejlesztését, valamint bővítését is.

Eredmények/következtetések

Az újabb műtéti technikák bevezetése mellett a Sebészeti Klinika Endoszkópos Laborjának fejlesztésével komoly lépéseket tettünk a colorectalis polypok komplex, multidiszciplináris ellátásának terén.

Kolorektal lateral yayılımlı tümörlerde başarısız endoskopik mukozal rezeksiyon sonrası endoskopik submukozal diseksiyonun uygulanabilirliği: tek merkez deneyimi

Aim: Endoscopic mucosal resection might technically be unsuccessful (interrupted endoscopic mucosal resection) in some cases when treating large colorectal laterally spreading tumors. In the literature, data on the outcomes of the endoscopic submucosal dissection method in endoscopic mucosal resection interrupted tumors are lacking. In this study, we evaluated the results of patients who underwent endoscopic submucosal dissection for endoscopic mucosal resection interrupted laterally spreading tumors. Materials and Methods: Between February 2019 and April 2021, 8 patients with endoscopic mucosal resection interrupted colorectal laterally spreading tumors underwent endoscopic submucosal dissection. The primary endpoint was en bloc, R0, and curative resection rates of endoscopic submucosal dissection. Results: In all cases, endoscopic submucosal dissection was successfully completed. The mean tumor size was 61.5 mm (35–100 mm). The rate of en bloc resection, R0 resection and curative resection was 100%, 87.5% and 87.5% respectively. Intra-procedural perforation occurred in 1 patient (12.5%) and was successfully treated with clip application. Delayed bleeding occurred in 1 patient (12.5%), and was successfully treated with endoluminal hemostasis. Furthermore, histopathological examination revealed that laterally spreading tumors in 4 patients (50.0%) had submucosal invasion. Surgical resection was performed after endoscopic submucosal dissection in 1 patient owing to the presence of deep submucosal invasion. Conclusion: Endoscopic submucosal dissection is an effective and relatively safe method in endoscopic mucosal resection interrupted colorectal laterally spreading tumors.

Real-time automated diagnosis of colorectal cancer invasion depth using a deep learning model with multimodal data (with video)

BACKGROUND AND AIMS

The optical diagnosis of colorectal cancer (CRC) invasion depth with white light (WL) and image-enhanced endoscopy (IEE) remains challenging. We aimed to construct and validate a 2-modal deep learning-based system, incorporated with both WL and IEE images (named Endo-CRC) in estimating the invasion depth of CRC.

METHODS

Samples were retrospectively obtained from 3 hospitals in China. We combined WL and IEE images into image pairs. Altogether, 337,278 image pairs from 268 noninvasive and superficial CRC and 181,934 image pairs from 82 deep CRC were used for training. A total of 296,644 and 4528 image pairs were used for internal and external tests and for comparison with endoscopists. Thirty-five videos were used for evaluating the real-time performance of the Endo-CRC system. Two deep learning models, solely using either WL (model W) or IEE images (model I), were constructed to compare with Endo-CRC.

RESULTS

The accuracies of Endo-CRC in internal image tests with and without advanced CRC were 91.61% and 93.78%, respectively, and 88.65% in the external test, which did not include advanced CRC. In an endoscopist-machine competition, Endo-CRC achieved an expert comparable accuracy of 88.11% and the highest sensitivity compared with all endoscopists. In a video test, Endo-CRC achieved an accuracy of 100.00%. Compared with model W and model I, Endo-CRC had a higher accuracy (per image pair: 91.61% vs 88.27% compared with model I and 91.61% vs 81.32% compared with model W).

CONCLUSIONS

The Endo-CRC system has great potential for assisting in CRC invasion depth diagnosis and may be well applied in clinical practice.

Endoscopic Recognition and Classification of Colorectal Polyps

Colonoscopy allows the performing endoscopist to thoroughly evaluate superficial colon lesions based on morphologic features such as size, location, shape, and surface pattern and also perform endoscopic resection where appropriate. Different elements of polyp characterization have been incorporated into systems that standardize this evaluation process and elucidate the likelihood of submucosal invasion or malignancy. Lesions which have invaded the submucosa are more likely to metastasize and are often not appropriate for endoscopic resection. It is, therefore, essential for the proceduralist to understand the multiple elements of lesion characterization and how they fit into the existing classification schemes.

SMALL AS WELL AS LARGE COLORECTAL LESIONS ARE EFFECTIVELY MANAGED BY ENDOSCOPIC MUCOSAL RESECTION TECHNIQUE

ABSTRACT Background Endoscopic mucosal resection (EMR) is an easy-to-use treatment option for superficial colorectal lesions, including lesions ≥20 mm. Objective To evaluate the effectiveness of EMR. Methods We evaluated 430 lesions removed by EMR in 404 patients. The lesions were analyzed according to their morphology, size, location, and histology. Lesions <20 mm were resected en bloc, whereas lesions ≥20 mm were removed by piecemeal EMR (p-EMR). Adverse events and recurrence were assessed. Results Regarding morphology, 145 (33.7%) were depressed lesions, 157 (36.5%) were polypoid lesions and 128 (29.8%) were laterally spreading lesions, with 361 (84%) lesions <20 mm and 69 (16%) ≥20 mm. Regarding histology, 413 (96%) lesions were classified as neoplastic lesions. Overall, 14 (3.3%) adverse reactions occurred, most commonly in lesions removed by p-EMR (P<0.001) and associated with advanced histology (P=0.008). Recurrence occurred in 14 (5.2%) cases, more commonly in lesions removed by p-EMR (P<0.001). Conclusion EMR is an effective technique for the treatment of superficial colorectal lesions, even of large lesions.

Large polyps: Pearls for the referring and receiving endoscopist

Polyps are precursors to colorectal cancer, the third most common cancer in the United States. Large polyps, i.e.,, those with a size ≥ 20 mm, are more likely to harbor cancer. Colonic polyps can be removed through various techniques, with the goal to completely resect and prevent colorectal cancer; however, the management of large polyps can be relatively complex and challenging. Such polyps are generally more difficult to remove en bloc with conventional methods, and depending on level of expertise, may consequently be resected piecemeal, leading to an increased rate of incomplete removal and thus polyp recurrence. To effectively manage large polyps, endoscopists should be able to: (1) Evaluate the polyp for characteristics which predict high difficulty of resection or incomplete removal; (2) Determine the optimal resection technique (e.g., snare polypectomy, endoscopic mucosal resection, endoscopic submucosal dissection, etc.); and (3) Recognize when to refer to colleagues with greater expertise. This review covers important considerations in this regard for referring and receiving endoscopists and methods to best manage large colonic polyps.

Colonoscopy may be weak link in organised colorectal cancer screening programme with faecal immunochemical test

OBJECTIVE

To evaluate the quality of colonoscopies performed after a positive faecal immunochemical test in the French colorectal cancer screening programme.

METHODS

Retrospective analysis of all colonoscopies performed between 2015 and 2019 after a positive quantitative faecal immunochemical test in the population-based colorectal cancer screening programme organised in Alsace, part of the French programme. The following indicators were evaluated: annual colonoscopy volume, caecal intubation rate, adenoma detection rate, proximal serrated lesion detection rate and proportion of patients referred directly to surgery for benign polyp management. Endoscopists who performed <30 faecal immunochemical test positive colonoscopies were non-assessable.

RESULTS

Overall, 13,455 faecal immunochemical test-positive colonoscopies performed by 116 community gastroenterologists were included, 13,067 of them by 80 assessable endoscopists. The overall caecal intubation, adenoma detection and proximal serrated lesion detection rates were 97.9%, 57.6% and 7.6%, respectively. They were <90%, <45% and <1% for 1.3%, 12.5% and 6.3% of the endoscopists, respectively. Overall, 1028 (7.9%) individuals were examined by 13 low-performing endoscopists and 328 (2.4%) individuals by 33 low-volume non-assessable endoscopists. Among 9133 individuals harbouring polyps, 155 (1.7%) had unwarranted surgery for a benign polyp. Overall, 1487 individuals (11.1%; 95% confidence interval 10.5-11.6) were not given the best possible chances, whereas 5545 individuals (41.2%; 95% confidence interval 40.4-42.0) were offered the best possible chances by 37 endoscopists.

CONCLUSIONS

At programme level, the key performance indicators evaluated largely exceeded the target standards. At individual level, at least one in nine individuals was not given the best possible chances during faecal immunochemical test-positive colonoscopies by a minority of poor-performing and/or low-volume endoscopists.

Multidisciplinary decision-making strategies may reduce the need for secondary surgery in complex colonic polyps - A systematic review and pooled analysis

AIM

The recognition of complex colonic polyps is increasing. Management varies considerably and the impact of this on clinical outcomes is unclear. The aim of this systematic review was to assess the impact of group decision-making strategies and defined selection criteria on the treatment outcomes of complex colonic polyps.

METHOD

A systematic literature review identified studies reporting complex polyp treatment outcomes and describing their decision-making strategies. Databases searched included PubMed, Web of Science, CINAHL and Scopus. Articles were identified by two blinded reviewers using defined inclusion criteria. The review protocol was registered on PROSPERO and performed in line with PRISMA guidelines.

RESULTS

There were 303 identified articles describing treatment outcomes of complex colonic polyps. Only nine of these fully described the decision-making strategy and met the inclusion criteria. Adverse events ranged from 1.3% to 10% across the studies. Unsuspected malignancy and secondary surgery rates ranged from 2.4% to 15.4% and 3.3% to 43.9%, respectively. Grouping of articles into a hierarchy of decision-making strategies demonstrated a sequential reduction in secondary surgery rates with improving strategies. There were no differences in comparisons of adverse event or unsuspected malignancy rates.

CONCLUSIONS

There is limited description of decision-making strategies and variability in reporting of studies describing complex polyp treatment outcomes. The use of multidisciplinary decision-making and defined selection criteria may reduce the need for secondary surgical intervention in complex colonic polyps, but further evidence is required to draw definite conclusions.

Endoscopic tissue sampling - Part 2: Lower gastrointestinal tract. European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE suggests performing segmental biopsies (at least two from each segment), which should be placed in different specimen containers (ileum, cecum, ascending, transverse, descending, and sigmoid colon, and rectum) in patients with clinical and endoscopic signs of colitis.Weak recommendation, low quality of evidence. 2: ESGE recommends taking two biopsies from the right hemicolon (ascending and transverse colon) and, in a separate container, two biopsies from the left hemicolon (descending and sigmoid colon) when microscopic colitis is suspected.Strong recommendation, low quality of evidence. 3: ESGE recommends pancolonic dye-based chromoendoscopy or virtual chromoendoscopy with targeted biopsies of any visible lesions during surveillance endoscopy in patients with inflammatory bowel disease. Strong recommendation, moderate quality of evidence. 4: ESGE suggests that, in high risk patients with a history of colonic neoplasia, tubular-appearing colon, strictures, ongoing therapy-refractory inflammation, or primary sclerosing cholangitis, chromoendoscopy with targeted biopsies can be combined with four-quadrant non-targeted biopsies every 10 cm along the colon. Weak recommendation, low quality of evidence. 5: ESGE recommends that, if pouch surveillance for dysplasia is performed, visible abnormalities should be biopsied, with at least two biopsies systematically taken from each of the afferent ileal loop, the efferent blind loop, the pouch, and the anorectal cuff.Strong recommendation, low quality of evidence. 6: ESGE recommends that, in patients with known ulcerative colitis and endoscopic signs of inflammation, at least two biopsies be obtained from the worst affected areas for the assessment of activity or the presence of cytomegalovirus; for those with no evident endoscopic signs of inflammation, advanced imaging technologies may be useful in identifying areas for targeted biopsies to assess histologic remission if this would have therapeutic consequences. Strong recommendation, low quality of evidence. 7: ESGE suggests not biopsying endoscopically visible inflammation or normal-appearing mucosa to assess disease activity in known Crohn's disease.Weak recommendation, low quality of evidence. 8: ESGE recommends that adequately assessed colorectal polyps that are judged to be premalignant should be fully excised rather than biopsied.Strong recommendation, low quality of evidence. 9: ESGE recommends that, where endoscopically feasible, potentially malignant colorectal polyps should be excised en bloc rather than being biopsied. If the endoscopist cannot confidently perform en bloc excision at that time, careful representative images (rather than biopsies) should be taken of the potential focus of cancer, and the patient should be rescheduled or referred to an expert center.Strong recommendation, low quality of evidence. 10: ESGE recommends that, in malignant lesions not amenable to endoscopic excision owing to deep invasion, six carefully targeted biopsies should be taken from the potential focus of cancer.Strong recommendation, low quality of evidence.

Management of large polyps in a colorectal cancer screening program with fecal immunochemical test: a community- and population-based observational study

Background and study aims  The aim of this study was to analyze presentation, management, and outcomes of large polyps (LPs; ≥ 20 mm) detected in a colorectal cancer (CRC) screening program using a quantitative fecal immunochemical test (FIT). Patients and methods  This was a retrospective community- and population-based observational study of all LPs detected in patients aged 50 to 74 years between 2015 and 2019 during FIT-positive colonoscopies within the screening program organized in Alsace (France). Results  Among 13,633 FIT-positive colonoscopies, 1256 LPs (8.5 % malignant and 51.8 % nonpedunculated) were detected by 102 community gastroenterologists in 1164 patients (one in 12 colonoscopies). The sensitivity of optical diagnosis of malignancy was 54 % for nonpedunculated and 27 % for pedunculated T1 CRCs. The endoscopic resection rate was 82.7 % (95 % confidence interval [CI] 80.3-84.9) for benign LPs (70.2 % [95 % CI 66.4-74.1]) nonpedunculated, 95.2 % [95 % CI 93.4-97.1] pedunculated), varying from 0 to 100 % depending on the endoscopist. It was correlated with cecal intubation (Pearson r  = 0.49, P  < 0.01) and adenoma detection rates ( r  = 0.25, P  = 0.01). Most endoscopists did not refer patients to more experienced endoscopists, and as a result, 60 % to 90 % of 183 surgeries for benign LPs were unwarranted. Endoscopic resection was curative for 4.3 % (95 % CI 0.9-12.0) of nonpedunculated and 37.8 % (95 % CI 22.5-55.2) of pedunculated T1 CRCs. Overall, 22 endoscopic submucosal dissections had to be performed to avoid one surgery. Conclusions  Compared with current recommendations, there is tremendous room for improvement in community endoscopy practices in the diagnosis and management of LPs. Detection and polypectomy competencies are correlated and highly variable among endoscopists. Endoscopic resection is curative for 83 % of benign LPs and 16 % of T1 CRCs.

Current Endoscopic Resection Techniques for Gastrointestinal Lesions: Endoscopic Mucosal Resection, Submucosal Dissection, and Full-Thickness Resection

Background

Endoscopic resection of dysplastic lesions in early stages of cancer reduces mortality rates and is recommended by many national guidelines throughout the world. Snare polypectomy and endoscopic mucosal resection (EMR) are established techniques of polyp removal. The advantages of these methods are their relatively short procedure times and acceptable complication rates. The latter include delayed bleeding in 0.9% and a perforation risk of 0.4-1.3%, depending on the size and location of the resected lesion. EMR is a recent modification of endoscopic resection. A limited number of studies suggest that larger lesions can be removed en bloc with low complication rates and short procedure times. Novel techniques such as endoscopic submucosal dissection (ESD) are used to enhance en bloc resection rates for larger, flat, or sessile lesions. Endoscopic full-thickness resection (EFTR) is employed for non-lifting lesions or those not easily amenable to resection. Procedures such as ESD or EFTR are emerging standards for lesions inaccessible to EMR techniques.

Summary

Endoscopic treatment is now regarded as first-line therapy for benign lesions.

Key Message

Endoscopic resection of dysplastic lesions or early stages of cancer is recommended. A plethora of different techniques can be used dependent on the lesions.

Concepts and prospects of minimally invasive colorectal cancer surgery

It is important that clinical radiologists understand and appreciate the minimally invasive surgery (MIS) options available to surgeons. Operative technologies are constantly evolving, and accurate, informed interpretation of clinical imaging is essential for optimum surgical management. Concurrent advancements in both MIS and radiological staging have certainly improved treatment decisions and outcomes. This article outlines the history, current concepts, evolving techniques, and future prospects of MIS as it pertains to colorectal cancer surgery.

Factors predicting occurrence and therapeutic choice in malignant colorectal polyps: a study of 13 years of colonoscopic polypectomy

Colorectal carcinoma represents a major cause of mortality and 0.2–12% of resected colonic polyps have malignant cells inside. We performed a retrospective study of patients with resected polyps during a period of 13 years. A total of 905 patients had 2033 polyps removed; 122 polyps (109 patients) had malignant cells. Prevalence of malignant polyps with submucosal invasion was 1.23% and for all polyps with malignant cells was 6%; malignant polyps had a larger size (23.44 mm mean diameter) vs benign polyps (9.63 mm); the risk of malignancy was increased in polyps larger than 10 mm, in lateral spreading lesions and in Paris types 0-Ip, 0-Isp, in sigmoid, descending colon and rectum, in sessile serrated adenoma and traditional serrate adenoma subtypes of serrated lesions and in tubulovillous and villous adenoma. In 18 cases surgery was performed, in 62 patients only colonoscopic follow-up was made and in 35 patients no colonoscopic follow-up was recorded. From initially endoscopic resected polyps, recurrence was noted in seven (11.3%) cases; there was a trend toward association with depth of invasion, piecemeal resection, right and rectum location, sessile and lateral spreading type and pathological subtype. In surgical group, post-therapeutic staging was available in 11 cases; nodal involvement was noted in three (27.27%) cases; none had lymphatic or vascular invasion in endoscopically resected polyps. Four patients with no macroscopic local recurrence underwent surgery with no residual tumor. The rate of metastasis was 16.67% in surgical group and 1.61% in endoscopic group. Evaluation of lymph node (LN) invasion was available for 11 operated patients, with LN invasion (N1) in three patients, local residual tumoral tissue in one patient with incomplete resection and no residual tumor (R0 resection) in four patients with endoscopic resection before surgery.

Management of early rectal cancer; current surgical options and future direction

Rectal cancer is the second commonest cause of cancer death within the United Kingdom. Utilization of national screening programmes have resulted in a greater proportion of patients presenting with early-stage disease. The technique of transanal endoscopic microsurgery was first described in 1984 following which further options for local excision have emerged with transanal endoscopic operation and, more recently, transanal minimally invasive surgery. Owing to the risks of local recurrence, the current role of minimally invasive techniques for local excision in the management of rectal cancer is limited to the treatment of pre-invasive disease and low risk early-stage rectal cancer (T1N0M0 disease). The roles of chemotherapy and radiotherapy for the management of early rectal cancer are yet to be fully established. However, results of high-quality research such as the GRECCAR II, TESAR and STAR-TREC randomised control trials may highlight a wider role for local excision surgery in the future, when used in combination with oncological therapies. The aim of our review is to provide an overview in the current management of early rectal cancer, the surgical options available for local excision and the future multimodal direction of early rectal cancer treatment.

Weekend and evening planned colonoscopy activity: a safe and effective way to meet demands

Background and study aims  Colonoscopy is the "gold standard" investigation for assessment of the large bowel that detects and prevents colorectal cancer, as well as non-neoplastic conditions. The Joint Advisory Group (JAG) on Gastrointestinal Endoscopy recommends monitoring key performance indicators such as cecal intubation rate (CIR) and adenoma detection rate (ADR). We aimed to investigate the quality of colonoscopies carried out during evening and Saturday lists in our unit and compare them against JAG standards of quality for colonoscopies. Patients and methods  We retrospectively collected and analyzed demographical and procedure-related data for non-screening colonoscopies performed between January 2016 and November 2018. Evenings and Saturdays were defined as the out-of-hour (OOH) period. We compared the outcomes of the procedures done in these against the working hours of the weekdays. We also wanted to explore whether the outcomes were different among certain endoscopists. Other factors that could affect the KPIs, such as endoscopist experience and bowel preparation, were also analyzed. Results  There were a total of 17634 colonoscopies carried out; 56.9 % of the patients (n = 10041) < 70 years old. Key Performance Indicators (KPIs) of weekday, evening, and Saturday colonoscopies regarding the CIR and ADR met the JAG standards as they were above 93 % and 24 %, respectively. Advanced colonoscopists had better KPIs when compared to the non-advanced colonoscopists, with CIR at 97.6 % vs. 93.2 % and ADR at 40.8 % vs. 26 %, respectively. Conclusions  JAG standards were maintained during colonoscopies done on weekdays, evenings, and Saturdays. Advanced colonoscopists had higher CIR and ADRs.

Histopathological features for coexistent invasive cancer in large colorectal adenomatous polyps

Background

Histopathological features associated with coexistent invasive adenocarcinoma in large colorectal adenomas have not been described. This study aimed to determine the association of histopathological features in areas of low-grade dysplasia with coexistent invasive adenocarcinoma.

Methods

High-grade lesions (containing high-grade dysplasia or adenocarcinoma) from a cohort of large (at least 20 mm) colorectal adenomas removed by endoscopic resection were subjected to detailed histopathological analysis. The histopathological features in low-grade areas with coexistent adenocarcinoma were reviewed and their diagnostic performance was evaluated.

Results

Seventy-four high-grade lesions from 401 endoscopic resections of large adenomas were included. In the low-grade dysplastic areas, a coexistent invasive adenocarcinoma was associated significantly with a cribriform or trabecular growth pattern (P < 0.001), high nuclear grade (P < 0.001), multifocal intraluminal necrosis (P < 0.001), atypical mitotic figures (P = 0.006), infiltrative lesion edges (P < 0.001), a broad fibrous band (P = 0.001), ulceration (P < 0.001), expansile nodules (P < 0.001) and an extensive tumour-infiltrating lymphocyte pattern (P = 0.04). Lesions with coexistent invasive adenocarcinoma harboured at least one of these features. The area under the receiver operating characteristic curve (AUROC) for coexistent invasive adenocarcinoma, using frequencies of adverse histopathological factors in low-grade areas, was 0.92. The presence of two or more of these adverse histopathological features in low-grade areas had a sensitivity of 86 per cent and a specificity of 84 per cent for coexistent invasive adenocarcinoma.

Conclusion

Several histopathological features in low-grade dysplastic areas of adenomas could be predictive of coexistent adenocarcinoma.

Serrated polyps of the colon and rectum: a concise review

"Serrated polyps" is the term used for epithelial lesions of the colon and rectum that have a "sawtooth" pattern on the polyp's surface and crypt epithelium. The so-called serrated pathway describes the progression of sessile serrated adenomas and traditional serrated adenomas to colorectal cancer. Said pathway is well recognized as an alternative mechanism of carcinogenesis and accounts for 15-30% of the cases of colorectal cancer. It also explains a large number of the cases of interval colorectal cancer. Thus, due to their usually aggressive and uncertain behavior, serrated polyps are of the utmost importance in colorectal cancer screening. Our aim was to review the history, current nomenclature, pathophysiology, morphology, treatment, and surveillance of serrated polyps.

iMAP: A Web Server for Metabolomics Data Integrative Analysis

Metabolomics data analysis depends on the utilization of bioinformatics tools. To meet the evolving needs of metabolomics research, several integrated platforms have been developed. Our group has developed a desktop platform IP4M (integrated Platform for Metabolomics Data Analysis) which allows users to perform a nearly complete metabolomics data analysis in one-stop. With the extensive usage of IP4M, more and more demands were raised from users worldwide for a web version and a more customized workflow. Thus, iMAP (integrated Metabolomics Analysis Platform) was developed with extended functions, improved performances, and redesigned structures. Compared with existing platforms, iMAP has more methods and usage modes. A new module was developed with an automatic pipeline for train-test set separation, feature selection, and predictive model construction and validation. A new module was incorporated with sufficient editable parameters for network construction, visualization, and analysis. Moreover, plenty of plotting tools have been upgraded for highly customized publication-ready figures. Overall, iMAP is a good alternative tool with complementary functions to existing metabolomics data analysis platforms. iMAP is freely available for academic usage at https://imap.metaboprofile.cloud/ (License MPL 2.0).

Hybrid endoscopic submucosal dissection: An alternative resection modality for large laterally spreading tumors in the cecum?

BACKGROUND

Endoscopic resection for large, laterally spreading tumors (LSTs) in the cecum is challenging. Here we report on the clinical outcomes of hybrid endoscopic submucosal dissection (ESD) in large cecal LSTs.

METHODS

We retrospectively reviewed data from patients with cecal LSTs ≥ 2 cm who underwent ESD or hybrid ESD procedures between January of 2008 and June of 2019. We compared the baseline characteristics and clinical outcomes, including procedure time, the en bloc and complete resection rates, and adverse events.

RESULTS

A total of 62 patients were enrolled in the study. There were 27 patients in the ESD group and 35 patients in the hybrid ESD group, respectively. Hybrid ESD was more used for lesions with submucosal fibrosis. No other significant differences were found in patient characteristics between the two groups. The hybrid ESD group had a significantly shorter procedure time compared with the ESD group (27.60 ± 17.21 vs. 52.63 ± 44.202 min, P = 0.001). The en bloc resection rate (77.1% vs. 81.5%, P = 0.677) and complete resection rate (71.4% vs. 81.5%, P = 0.359) of hybrid ESD were relatively lower than that of the ESD group in despite of no significant difference was found. The perforation and post-procedure bleeding rate (2.9% vs. 3.7%, P = 0.684) were similar between the two groups. One patient perforated during the ESD procedure, which was surgically treated. One patient in the hybrid ESD group experienced post-procedure bleeding, which was successfully treated with endoscopic hemostasis. Post-procedural fever and abdominal pain occurred in six patients in the ESD group and five patients in the hybrid ESD group. One patient in the ESD group experienced recurrence, which was endoscopically resected.

CONCLUSION

The results of this study indicate that hybrid ESD may be an alternative resection strategy for large cecal LSTs with submucosal fibrosis.

The number of biopsy specimens can influence the non-lifting sign in colorectal laterally spreading tumors

BACKGROUND

 Although the problem of whether to perform a biopsy before endoscopic treatment for colorectal laterally spreading tumor (LST) troubles clinicians, about 50 % of lesions still undergo a preceding biopsy. We aimed to explore factors affecting the non-lifting sign in LST and examine the influence of "biopsy-related factors", such as the number of biopsy specimens and the interval after biopsy on non-lifting sign in cases with a history of biopsy.

METHODS

 Clinical data of 159 LSTs regarding age, gender, history of biopsy, tumor location, tumor size, the depth of submucosal invasion, tumor configuration, histologic type, location with respect to the fold, and result of non-lifting sign testing were investigated retrospectively. For patients with a history of biopsy, the period after biopsy and the number of biopsy specimens also were analyzed.

RESULTS

 Among 159 cases of LST, 112 were positive and 47 were negative for lifting signs. Biopsy history (p = 0.008), tumor size (p = 0.010), and location with respect to the fold (p = 0.022) were identified as factors affecting the non-lifting sign in multivariate analyses. In 75 LST cases with a history of biopsy, only the number of biopsies (p = 0.003) was identified as a factor affecting the non-lifting sign in multivariate analyses.

CONCLUSIONS

 For LST, lesions with larger size, being across the fold, and biopsy history were predictive factors for non-lifting signs. Reducing the number of biopsies would reduce the occurrence of non-lifting signs when biopsy is necessary. The impact of the interval after the biopsy on the non-lifting sign will require further study.

Insufflation of Carbon Dioxide versus Air During Colonoscopy Among Pediatric Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background/Aims:

Carbon dioxide is increasingly used in insufflation during colonoscopy in adult patients; however, air insufflation remains the primary practice among pediatric gastroenterologists. This systematic review and meta-analysis aims to evaluate insufflation using CO₂ versus air in colonoscopies in pediatric patients.

Methods:

Individualized search strategies were performed using MEDLINE, Cochrane Library, EMBASE, and LILACS databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Cochrane working methodology. Randomized control trials (RCTs) were selected for the present meta-analysis. Pooled proportions were calculated for outcomes including procedure time and abdominal pain immediately and 24 hours post-procedure.

Results:

The initial search yielded 644 records, of which five RCTs with a total of 358 patients (CO₂: n=178 versus air: n=180) were included in the final analysis. The procedure time was not different between the CO₂ and air insufflation groups (mean difference, 10.84; 95% confidence interval [CI], -2.55 to 24.22; p=0.11). Abdominal pain immediately post-procedure was significantly lower in the CO₂ group (risk difference [RD], -0.15; 95% CI; -0.26 to -0.03; p=0.01) while abdominal pain at 24 hours post-procedure was similar (RD, -0.05; 95% CI; -0.11 to 0.01; p=0.11).

Conclusions:

Based on this systematic review and meta-analysis of RCT data, CO₂ insufflation reduced abdominal pain immediately following the procedure, while pain was similar at 24 hours post-procedure. These results suggest that CO₂ is a preferred insufflation technique when performing colonoscopy in pediatric patients.

Multiparametric MRI-based machine learning models for preoperatively predicting rectal adenoma with canceration

OBJECTIVES

To propose multiparametric MRI-based machine learning models and assess their ability to preoperatively predict rectal adenoma with canceration.

MATERIALS AND METHODS

A total of 53 patients with postoperative pathology confirming rectal adenoma (n = 29) and adenoma with canceration (n = 24) were enrolled in this retrospective study. All patients were divided into a training cohort (n = 42) and a test cohort (n = 11). All patients underwent preoperative pelvic MR examination, including high-resolution T2-weighted imaging (HR-T2WI) and diffusion-weighted imaging (DWI). A total of 1396 radiomics features were extracted from the HR-T2WI and DWI sequences, respectively. The least absolute shrinkage and selection operator (LASSO) was utilized for feature selection from the radiomics feature sets from the HR-T2WI and DWI sequences and from the combined feature set with 2792 radiomics features incorporating two sequences. Five-fold cross-validation and two machine learning algorithms (logistic regression, LR; support vector machine, SVM) were utilized for model construction in the training cohort. The diagnostic performance of the models was evaluated by sensitivity, specificity and area under the curve (AUC) and compared with the Delong's test.

RESULTS

Ten, 8, and 25 optimal features were selected from 1396 HR-T2WI, 1396 DWI and 2792 combined features, respectively. Three group models were constructed using the selected features from HR-T2WI (Model_T2), DWI (Model_DWI) and the two sequences combined (Model_combined). Model_combined showed better prediction performance than Model_T2 and Model_DWI. In Model_combined, there was no significant difference between the LR and SVM algorithms (p = 0.4795), with AUCs in the test cohort of 0.867 and 0.900, respectively.

CONCLUSIONS

Multiparametric MRI-based machine learning models have the potential to predict rectal adenoma with canceration. Compared with Model_T2 and Model_DWI, Model_combined showed the best performance. Moreover, both LR and SVM have equal excellent performance for model construction.

Metachronous neoplasms in patients with laterally spreading tumours during surveillance

Background

Laterally spreading tumours represent a major challenge for endoscopic detection and resection.

Objective

To examine synchronous and metachronous neoplasms in patients with laterally spreading tumours.

Methods

We prospectively collected colonoscopy and histopathology data from patients who underwent colonoscopy in our centre at up to 6 years' follow‐up. Post‐resection surveillance outcomes between laterally spreading tumours, flat colorectal neoplasms 10 mm or greater, and large polypoid colorectal neoplasms, polypoid colorectal neoplasms 10 mm or greater, were compared.

Results

Between 2008 and 2012, 8120 patients underwent colonoscopy for symptoms (84.6%), screening (6.7%) or surveillance (8.7%). At baseline, 151 patients had adenomatous laterally spreading tumours and 566 patients had adenomatous large polypoid colorectal neoplasms. Laterally spreading tumour patients had more synchronous colorectal neoplasms than large polypoid colorectal neoplasm patients (mean 3.34 vs. 2.34, p < 0.001). Laterally spreading tumour patients significantly more often developed metachronous colorectal neoplasms (71.6% vs. 54.2%, p = 0.0498) and colorectal neoplasms with high grade dysplasia/submucosal invasion than large polypoid colorectal neoplasm patients (36.4% vs. 15.8%, p < 0.001). After correction for age and gender, laterally spreading tumour patients were more likely than large polypoid colorectal neoplasm patients to develop a colorectal neoplasm with high grade dysplasia or submucosal invasion (hazard ratio 2.9, 95% confidence interval 1.8–4.6). The risk of metachronous colorectal cancer was not significantly different in laterally spreading tumours compared to large polypoid colorectal neoplasm patients.

Conclusion

Patients with laterally spreading tumours developed more metachronous colorectal neoplasms with high grade dysplasia/submucosal invasion than large polypoid colorectal neoplasm patients. Based on these findings endoscopic treatment and surveillance recommendations for patients with laterally spreading tumours should be optimised.

Summarize the established knowledge on this subject

Laterally spreading tumours (LSTs) are a heterogeneous group of large, predominantly benign flat neoplasms that can be endoscopically treated, requiring additional time and expertise

LSTs consist of different endoscopic subtypes which are predictive of the risk of submucosal invasion (SMI)

Patients with LSTs harbour more synchronous neoplasms than patients with large polypoid colorectal neoplasms (LP‐CRNs)

What are the significant and/or new findings of this study?

Patients with LSTs more frequently have metachronous neoplasms than patients with LP‐CRNs, justifying strict surveillance

LSTs can be effectively managed by conventional endoscopic resections in most cases

Rectum versus colon: should malignant polyps be treated differently?

BACKGROUND

The management of malignant colorectal polyps removed at endoscopy remains controversial with patients either undergoing surgical resection or regular endoscopic surveillance. Lymph node (LN) metastases occur in 6-16% of patients with malignant polyps. This study assessed the rate of LN metastases in patients undergoing surgical resection for malignant polyps removed endoscopically to determine if there is a difference in the rate of LN metastases between colonic and rectal polyps.

METHODS

A retrospective review of a prospectively maintained database was performed from 2010 to 2018. All patients who underwent surgical resection following endoscopic removal of a malignant colorectal polyp were reviewed. Clinical data including patient demographics and tumour characteristics were examined.

RESULTS

A total of 177 patients underwent surgical resection in the study period. The median age at diagnosis was 65 years (range 22-88 years) with females comprising 52% of the patient cohort (n = 92/177). Polyps were located in the colon in 60.5% of cases with the remainder located in the rectum. The median number of LN harvested was 14 (range 0-44) with malignant LN (including a mesenteric tumour deposit) identified in 8.5% of resection specimens (n = 15/177). Malignant LNs were retrieved in 5.5% of right-sided tumours, 5.6% of left-sided tumours and 12.9% of rectal tumours (P = 0.090).

CONCLUSION

A small proportion of patients with malignant polyps removed endoscopically will have LN metastases. The results of this study suggest that the tumour location might be a useful predictive marker; however, a further study with increased patient numbers is required to properly establish this finding.

Rectal neoplasia extending to the dentate line: clinical outcomes of endoscopic submucosal dissection

BACKGROUND

The European Society of Gastrointestinal Endoscopy (ESGE) and the Japan Gastroenterological Endoscopy Society (JGES) give no specific recommendations on the best treatment for colorectal neoplasia involving the dental line (DLCN).

OBJECTIVE

Aim of this study was to analyse efficacy and safety of Endoscopic Submucosal Dissection in the treatment of colorectal neoplasia involving the dentate line (DLCN) compared to non-DLCN.

DESIGN

Retrospective study.

PATIENTS

We retrospectively evaluated all consecutive patients undergoing ESD for rectal neoplasia at two endoscopical tertiary referral centers (Italy and Japan) from January 2008 to December 2019.

MAIN OUTCOME MEASURES

Anthropometric, clinical, procedural, and follow-up data was collected, analysed, and compared between patients with DLCN and patients with non-DLCN.

RESULTS

Overall, 314 patients were enrolled (163 female, 51.9%). Mean age was 68 years (range, 32-92 years). En-bloc resection was achieved in 311/314 (99%) patients. Lesion size was higher in DLCN group than in the non-DLCN group (46.1 vs 38.9 mm; p = .03). Submucosal invasion rate was also higher in the DLCN group (29.6 vs 18.4%, p = .04). Procedure time was significantly longer in the DLCN group, (89.6 vs. 73.1 min; p = .002). Hospitalization length following ESD was similar in both groups.

LIMITATIONS

Retrospective study design.

CONCLUSIONS

ESD seems to be safe and effective in the treatment of colorectal neoplasia involving the dentate line and can be considered the best therapeutic strategy.

Improving assessment and management of large non-pedunculated colorectal lesions in a Western center over 10 years: lessons learned and clinical impact

Background and study aims  Outcomes of endoscopic assessment and management of large colorectal (CR) non-pedunculated lesions (LNPLs) are still under evaluation, especially in Western settings. We analyzed the clinical impact of changes in LNPL management over the last decade in a European center. Patients and methods  All consecutive LNPLs ≥ 20 mm endoscopically assessed (2008-2019) were retrospectively included. Lesion, patient, and resection characteristics were compared among clinically relevant subgroups. Multivariate logistic regression (for predictors of submucosal invasion [SMI] and recurrence), Kaplan-Meier curves and ROC curves (for temporal cut-offs in trends analyses) were used. Results  A total of 395 LNPLs were included (30 mm [range 20-40]; SMI = 9.6 %; primary endoscopic resection [ER] = 88.4 %). Pseudo-depression and JNET classification independently predicted SMI beyond single morphologies/location. After complete ER, involvement of ileocecal valve/dentate line, piece-meal resection and high-grade dysplasia independently predicted recurrence. Rates of 5-year recurrence-free, surgery-free and cancer-free survival were 77.5 %, 98.6 % and 100 %, respectively, with 93.8 % recurrences endoscopically managed and no death attributable to ER or CR cancer (versus 3.4 % primary surgery mortality). ROC curves identified the period ≥ 2015 (following Endoscopic Submucosal Dissection [ESD] introduction and education on pre-resective lesion assessment) as associated with improved lesions' characterization, increased en-bloc resection of SMI lesions (87.5 % vs 37.5 %; p = 0.0455), reduced primary surgery (7.5 % vs 16.7 %; p = 0.0072), surgical referral of benign lesions (5.1 % vs 14.8 %; p = 0.0019), and recurrences. Conclusions  ESD introduction and educational interventions allowed ER of more complex lesions, offset by increased complementary surgery for complications or intrinsic histological risk. Nevertheless, overall, they have reduced surgery demand and increased appropriateness and safety of LNPL management in our center.