Complete resection of colorectal adenomas: what are the important factors in fellow training?

Risk factors for unclear margin in cold snare polypectomy for colorectal polyp

OBJECTIVES

Cold snare polypectomy (CSP) is a common, simple, and safe procedure; however, it has a high rate of unclear margins. We analyzed the risk factors for unclear margins of colorectal polyp.

METHODS

We retrospectively investigated colorectal polyps treated with CSP between July 2021 and July 2022, excluding those that could not be retrieved or pathologically nonneoplastic and hyperplastic polyps without margin evaluation. The clinicopathological features and risk factors for unclear margins were analyzed. Furthermore, the polyps were divided into two groups: those resected by experts and those resected by trainees. A 1 : 1 propensity score matching was performed. After matching, the risk factors for unclear margins in each group were analyzed as secondary outcomes.

RESULTS

We analyzed 237 patients with 572 polyps; the margins were negative in 58.6% (negative group) and unclear in 41.4% (unclear group). The unclear margin was significantly higher at straddling folds (P = 0.0001), flexure points (P = 0.005), and in the procedures performed by trainees (P < 0.0001). Altogether, 198 propensity score matched pairs were explored for secondary outcomes. There were no significant differences in risk factors for unclear margins in the expert group, while in the trainee group, the unclear margin was significantly higher at the straddling folds (P = 0.0004) and flexure points (P = 0.005).

CONCLUSIONS

We demonstrated that straddling folds, flexure points, and procedures performed by the trainees were significant risk factors for unclear margins, and we hypothesized that the rate of unclear margins will reduce as the trainees accumulate experience at difficult sites.

Clinical outcomes and learning curve of Tip-in endoscopic mucosal resection for 15-25 mm colorectal neoplasms among non-experts

BACKGROUND AND AIM

Tip-in endoscopic mucosal resection (EMR) has a high en bloc resection rate for large colorectal neoplasms. However, non-experts' performance in Tip-in EMR has not been investigated. We investigated whether Tip-in EMR can be achieved effectively and safely even by non-experts.

METHODS

This retrospective study included consecutive patients who underwent Tip-in EMR for 15-25 mm colorectal nonpedunculated neoplasms at a Japanese tertiary cancer center between January 2014 and December 2020. Baseline characteristics, treatment outcomes, learning curve of non-experts, and risk factors of failing self-achieved en bloc resection were analyzed.

RESULTS

A total of 597 lesions were analyzed (438 by experts and 159 by non-experts). The self-achieved en bloc resection (69.8% vs 88.6%, P < 0.001) and self-achieved R0 resection (58.3% vs 76.5%, P < 0.001) rates were significantly lower in non-experts with <10 cases of experience than in experts, but not in non-experts with >10 cases. Adverse event (P = 0.165) and local recurrence (P = 0.892) rates were not significantly different between experts and non-experts. Risk factors of failing self-achieved en bloc resection were non-polypoid morphology (OR 3.4, 95% CI 1.6-7.3, P = 0.001), lesions with an underlying semilunar fold (OR 3.6, 95% CI 1.6-7.3, P < 0.001), positive non-lifting sign (OR 3.1, 95% CI 1.2-8.0, P = 0.023), and non-experts with an experience of ≤10 cases (OR 3.6, 95% CI 2.1-6.3, P < 0.001).

CONCLUSION

The clinical outcomes of Tip-in EMR for 15-25 mm lesions performed by non-experts were favorable.

COLD SNARE POLYPECTOMY: A SAFE PROCEDURE FOR REMOVING SMALL NON-PEDUNCULATED COLORECTAL LESIONS

BACKGROUND

Polypectomy is an important treatment option for preventing colorectal cancer. Incomplete polyp resection (IPR) is re-cognized as a risk factor for interval cancer.

OBJECTIVE

The primary objective was to evaluate the complete polyp resection (CPR) rate for cold snare polypectomy (CSP) in small non-pedunculated polyps and, secondarily, specimen retrieval and complication rates.

METHODS

We prospectively evaluated 479 polyps <10 mm removed by CSP in 276 patients by an inexperienced endoscopist.

RESULTS

A total of 476 polyps (99.4%) were resected en bloc. A negative margin (classified as CPR) was observed in 435 polyps (90.8%). An unclear or positive margin (classified as IPR) was observed in 43 cases (9.0%) and 1 case (0.2%), respectively, for an overall IPR rate of 9.2% (44/479). The IPR rate was 12.2% in the first half of cases and 5.9% in the second half (P=0.02). Dividing into tertiles, the IPR rate was 15.0% in the first tertile, 6.9% in the second tertile, and 5.7% in the third tertile (P=0.01). Dividing into quartiles, the IPR rate was 15.8% in the first quartile and 5.9% in the fourth quartile (P=0.03). The IPR rate was 6.3% for type 0-IIa lesions and 14.1% for type 0-Is lesions (P=0.01). For serrated and adenomatous lesions, the IPR rate was 9.2%. Specimen retrieval failed in 3.6% of cases. Immediate bleeding (>30 s) occurred in 1 case (0.2%), treated with argon plasma coagulation. No delayed bleeding or perforation occurred.

CONCLUSION

CSP is a safe technique that provides good results for the resection of small non-pedunculated polyps, with a short learning curve.

Quality Indicators for the Detection and Removal of Colorectal Polyps and Interventions to Improve Them

Modifiable risk factors for postcolonoscopy colorectal cancer include suboptimal lesion detection (missed neoplasms) and inadequate lesion removal (incomplete polypectomy) during colonoscopy. Competent detection and removal of colorectal polyps are thus fundamental to ensuring adequate colonoscopy quality. Several well-researched quality metrics for polyp detection have been implemented into clinical practice, chief among these the adenoma detection rate. Less data are available on quality indicators for polyp removal, which currently include complete resection rates and skills assessment tools. This review summarizes the available literature on quality indicators for the detection and removal of colorectal polyps, as well as interventions to improve them.

Endoscopic resection outcomes and predictors of failed en bloc endoscopic mucosal resection of colorectal polyps ≤ 20 mm among advanced endoscopy trainees

Background and study aims  En bloc endoscopic mucosal resection (EMR) is preferred over piecemeal resection for polyps ≤ 20 mm. Data on colorectal EMR training are limited. We aimed to evaluate the en bloc EMR rate of polyps ≤ 20 mm among advanced endoscopy trainees and to identify predictors of failed en bloc EMR. Methods  This was a multicenter prospective study evaluating trainee performance in EMR during advanced endoscopy fellowship. A logistic regression model was used to identify the number of procedures and lesion cut-off size associated with an en bloc EMR rate of ≥ 80 %. Multivariate analysis was performed to identify predictors of failed en bloc EMR. Results  Six trainees from six centers performed 189 colorectal EMRs, of which 104 (55 %) were for polyps ≤ 20 mm. Of these, 57.7 % (60/104) were resected en bloc. Trainees with ≥ 30 EMRs (OR 6.80; 95 % CI: 2.80-16.50; P  = 0.00001) and lesions ≤ 17 mm (OR 4.56;95 CI:1.23-16.88; P  = 0.02) were more likely to be associated with an en bloc EMR rate of ≥ 80 %. Independent predictors of failed en bloc EMR on multivariate analysis included: larger polyp size (OR:6.83;95 % CI:2.55-18.4; P  = 0.0001), right colon location (OR:7.15; 95 % CI:1.31-38.9; P  = 0.02), increased procedural difficulty (OR 2.99; 95 % CI:1.13-7.91; P  = 0.03), and having performed < 30 EMRs (OR: 4.87; 95 %CI: 1.05-22.61; P  = 0.04). Conclusions  In this pilot study, we demonstrated that a relatively low proportion of trainees achieved en bloc EMR for polyps ≤ 20 mm and identified procedure volume and lesion size thresholds for successful en bloc EMR and independent predictors for failed en bloc resection. These preliminary results support the need for future efforts to define EMR procedure competence thresholds during training.

Evaluating learning curves and competence in colorectal EMR among advanced endoscopy fellows: a pilot multicenter prospective trial using cumulative sum analysis

BACKGROUND AND AIMS

Data on colorectal EMR (C-EMR) training are lacking. We aimed to evaluate C-EMR training among advanced endoscopy fellows (AEFs) by using a standardized assessment tool (STAT).

METHODS

This multicenter prospective study used a STAT to grade AEF training in C-EMR during their 12-month fellowship. Cumulative sum analysis was used to establish learning curves and competence for cognitive and technical components of C-EMR and overall performance. Sensitivity analysis was performed by varying failure rates. AEFs completed a self-assessment questionnaire to assess their comfort level with performing C-EMR at the completion of their fellowship.

RESULTS

Six AEFs (189 C-EMRs; mean per AEF, 31.5 ± 18.5) were included. Mean polyp size was 24.3 ± 12.6 mm, and mean procedure time was 22.6 ± 16.1 minutes. Learning curve analyses revealed that less than 50% of AEFs achieved competence for key cognitive and technical C-EMR endpoints. All 6 AEFs reported feeling comfortable performing C-EMR independently at the end of their training, although only 2 of them achieved competence in their overall performance. The minimum threshold to achieve competence in these 2 AEFs was 25 C-EMRs.

CONCLUSIONS

A relatively low proportion of AEFs achieved competence on key cognitive and technical aspects of C-EMR during their 12-month fellowship. The relatively low number of C-EMRs performed by AEFs may be insufficient to achieve competence, in spite of their self-reported readiness for independent practice. These pilot data serve as an initial framework for competence threshold, and suggest the need for validated tools for formal C-EMR training assessment.

Systematic literature review of learning curves for colorectal polyp resection techniques in lower gastrointestinal endoscopy

AIM

The performance of therapeutic procedures in lower gastrointestinal endoscopy (LGI) can be challenging and carries an increased risk of adverse events. There is increasing demand for the training of endoscopists in these procedures, but limited guidelines exist concerning procedural competency. The aim of this study was to assess the learning curves for LGI polypectomy, colorectal endoscopic mucosal resection (EMR) and colorectal endoscopic submucosal dissection (ESD).

METHOD

A systematic review of electronic databases between 1946 and September 2019 was performed. Citations were included if they reported learning curve data. Outcome measures that defined the success of procedural competency were also recorded.

RESULTS

A total of 34 out of 598 studies met the inclusion criteria of which 28 were related to ESD, three to polypectomy and three to EMR. Outcome measures for polypectomy competency (en bloc resection, delayed bleeding and independent polypectomy rate) were achieved after completion of between 250 and 400 polypectomies and after 300 colonoscopies. EMR outcome measures, including complete resection and recurrence, were achieved variably between 50 and 300 procedures. Outcome measures for ESD included efficiency (resection rates and procedural speed) and safety (adverse events). En bloc resection rates of over 80% and R0 resection rates of over 70% were achieved at 20-40 cases and procedural speed increased after 30 ESD cases. Competency in safety metrics was variably achieved at 20-200 cases.

CONCLUSION

There is a paucity of data on learning curves in LGI polypectomy, EMR and ESD. Despite limited evidence, we have identified relevant outcome measures and threshold numbers for the most common LGI polyp resection techniques for potential inclusion in training programmes/credentialing guidelines.

Assessing the Quality of Polypectomy and Teaching Polypectomy

Ineffective polypectomy technique may lead to incomplete polyp resection, high complication rates, interval colorectal cancer, and costly referral to surgery. Despite its central importance to endoscopy, training in polypectomy is not standardized nor has the most effective training approach been defined. Polypectomy competence is rarely reported and quality metrics for this skill are lacking. Use of tools and measurements to assess polypectomy outcomes is low. There is a need for standardization of training and remediation in polypectomy; defining standards of competent polypectomy and how it is feasibly measured; and integration of polypectomy quality metrics into training programs and the accreditation process.

Risk factors for incomplete polyp resection after cold snare polypectomy

BACKGROUND

Incomplete polyp resection (IPR) is recognized as a risk factor for interval colorectal cancer (ICC), and is, therefore, an important issue in polypectomy. Cold snare polypectomy (CSP) is a procedure that does not involve electrocautery and has no burn effect. Therefore, there is the possibility that the risk of ICC associated with IPR is higher in cases undergoing CSP than in those undergoing hot polypectomy. However, little is known about the risk factors for IPR after CSP.

PURPOSE

Precise identification of the risk factors can lead to prevention of IPR after CSP. Therefore, we performed this observational study for accurate identification of the risk factors for IPR after CSP.

METHODS

Medical records of a total of 501 patients with 1177 colorectal polyps that were resected at Omori Red Cross Hospital between October 2017 and March 2018 were retrospectively reviewed. The lateral and deep margins of the resected polyps were evaluated to check for the resection completeness.

RESULTS

Among the 1177 polyp resections, 1163 were included in the final analysis. IPR was detected in 206 (17.7%) cases. Performance of the resection by a trainee (OR (95% CI) 1.87 (1.328-2.632); P < 0.001) was identified as an independent risk factor for IPR in patients undergoing CSP.

CONCLUSIONS

Performance of the polypectomy by a trainee was identified as a significant risk factor for IPR in patients undergoing CSP. Prospective, randomized studies are necessary in the future to develop effective methods for the prevention/control of IPR after CSP.

Endoscopic resection for small esophageal submucosa tumor: Band ligation versus conventional endoscopic mucosal resection

Because an esophageal submucosa tumor (SMT) may be malignant despite its small size, a safe endoscopic resection method is needed in some small SMTs. Conventional endoscopic mucosal resection (EMR) may be simple, but incomplete pathologic resection margin status is common. We aimed to investigate the clinical outcomes of 2 kinds of EMR techniques (conventional EMR and EMR with band ligation device) and to evaluate the factors associated with incomplete pathologic resection.We evaluated the medical records of 36 patients. All lesions were esophageal SMTs located in the submucosa or muscularis mucosa less than 10 mm in size by endoscopic ultrasound (EUS). The clinical outcomes based on the endoscopic procedures and factors associated with incomplete pathologic resection were evaluated.The mean tumor size was 6.6 ± 4.1 mm. The overall en bloc and complete resection rates were 100% and 80.6%, respectively. No procedure-related complications, such as perforation and bleeding, were found. Univariate analysis showed that complete resection rates were higher in granular cell tumors than in leiomyomas (82.8% vs 17.2%, P = .029), tumors located in the submucosa layer than in the muscularis mucosa (96.6% vs 3.4%, P = .003), and in EMR with band ligation device than in conventional EMR (82.8% vs 17.2%, P < .001). Multivariate analysis showed that conventional EMR was the only significant factor associated with incomplete resection (OR, 35.594; 95% CI, 2.042-520.329; P = .014)EMR with a band ligation device is an effective and safe treatment method for small esophageal SMT.

Characteristics and outcomes of endoscopically resected colorectal cancers that arose from sessile serrated adenomas and traditional serrated adenomas

Background/Aims

The efficacy and safety of endoscopic resection of colorectal cancer derived from sessile serrated adenomas or traditional serrated adenomas are still unknown. The aims of this study were to verify the characteristics and outcomes of endoscopically resected early colorectal cancers developed from serrated polyps.

Methods

Among patients who received endoscopic resection of early colorectal cancers from 2008 to 2011, cancers with documented pre-existing lesions were included. They were classified as adenoma, sessile serrated adenoma, or traditional serrated adenoma according to the baseline lesions. Clinical characteristics, pathologic diagnosis, and outcomes were reviewed.

Results

Overall, 208 colorectal cancers detected from 198 patients were included: 198 with adenoma, five with sessile serrated adenoma, and five with traditional serrated adenoma. The sessile serrated adenoma group had a higher prevalence of high-grade dysplasia (40.0% vs. 25.8%, P<0.001) than the adenoma group. During follow-up, local recurrence did not occur after endoscopic resection of early colorectal cancers developed from serrated polyps. In contrast, two cases of metachronous recurrence were detected within a short follow-up period.

Conclusions

Cautious observation and early endoscopic resection are recommended when colorectal cancer from serrated polyp is suspected. Colorectal cancers from serrated polyp can be treated successfully with endoscopy.

Measures of trainee performance in advanced endoscopy: A systematic review

INTRODUCTION

The diversity, technical skills required, and risk inherent to advanced endoscopy techniques all contribute to complex training curricula and steep learning curves. Since trainees develop endoscopy skills at different rates, there has been a shift towards competency-based training and certification. Validated endoscopy performance measures for trainees are, therefore, necessary. The aim of this systematic review was to describe and critically assess the existing evidence regarding measures of performance for trainees in advanced endoscopy.

METHODS

A systematic review of the literature from January 1980 to January 2016 was carried out using the MEDLINE, EMBASE, CENTRAL, and ISI Web of knowledge databases. MeSH terms related to 'advanced endoscopy' and 'performance' were applied to a highly sensitive search strategy. The main outcomes were face, content, and construct validity, as well as reliability.

RESULTS

The literature search yielded 1,662 studies and 77 met the inclusion criteria after abstract and full-text review (endoscopic retrograde cholangiopancreatography (ERCP)=23, endoscopic ultrasound (EUS)=30, colonoscopic polypectomy (CP)=11, balloon-assisted enteroscopy (BAE)=7, luminal stenting=3, radiofrequency ablation (RFA)=2, and endoscopic muscosal resection (EMR)=1). Good validity and reliability were found for measurement tools of overall performance in ERCP, EUS and CP, with applications for both patient-based and simulator training models. A number of specific technical skills were also shown to be valid measures of performance. These include: selective biliary cannulation, sphincterotomy, biliary stent placement, stone extraction and procedure time for ERCP; pancreatic solid mass T-staging, EUS-guided fine needle aspiration (EUS-FNA) procedure time, number of EUS-FNA passes and puncture precision for EUS; procedure time and en bloc resection rate for CP; retrograde fluoroscopy time for BAE; and mean number of endoscopy sessions required to achieve complete eradication of intestinal metaplasia (CIEM) for RFA. The evidence for EMR and luminal stenting is of insufficient quality to make recommendations.

CONCLUSIONS

We have identified multiple valid and readily available performance measures for advanced endoscopy trainees for ERCP, EUS, CP, BAE and RFA procedures. These tools should be considered in advanced endoscopy training programs wishing to move away from apprenticeship-based training and towards competency-based learning with the help of patient-based and simulator tools.