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

Dual Channel Endoscopic Mucosal Resection

Endoscopic mucosal resection (EMR) is the recommended technique for colon polypectomy for nonpedunculated lesions that are >20 mm in size not requiring excision. Dual-channel EMR (DC-EMR) uses an endoscope with two working channels to facilitate easier submucosal injection, snare resection, and clip closure of polypectomy defects. There is also promising early literature indicating that this endoscopic modality can reduce the overall learning curve present for single-channel colonoscopy EMR. This chapter will describe the steps and techniques required to perform DC-EMR, potential complications, recommended postprocedure surveillance, and future directions.

Outcomes of endoscopic sub-mucosal dissection in laterally spreading colorectal polyps: A tertiary care centre experience from India

BACKGROUND

Endoscopic sub-mucosal dissection (ESD) is an established endoscopic modality for the management of colorectal polyps. However, there are no studies regarding the outcomes of ESD from India. In this study, we aimed at evaluating the outcomes of ESD in patients with adenomatous polyps in the colon and rectum.

METHODS

Data of consecutive patients who underwent ESD for colorectal polyps from 2018 to 2021 were analyzed, retrospectively. The primary outcome of the study was the technical success of ESD. The secondary outcomes included the rate of histologically complete resection (R0), adverse events and recurrence.

RESULTS

Seventy patients (63.5 years, 60% males) underwent ESD for polyps in colon and rectum. A majority were located in rectum (80%) and sigmoid colon (15.7%). Narrow band classification of the polyps was Japanese Narrow Band Imaging Expert Team (JNET)-2a in 50 (71.4%) and JNET-2b in 13 (18.6%) patients. ESD was technically successful in 64 (91.4%) patients using conventional technique (72.8%) and pocket or tunnelling technique (18.6%). There were no major adverse events. Histologically RO was achieved in 58 (82.8%) patients and deep sub-mucosal invasion was noted in 12 patients. At a median follow-up of 19 (interquartile range [IQR] 15-27) months, recurrence was noticed in four (5.7%) patients all of which could be managed endoscopically.

CONCLUSION

ESD, performed at a tertiary care centre in India, yields high rates of technical success and histologically R0, with a relatively low incidence of adverse events and recurrences.

Endoscopic En Bloc Versus Piecemeal Resection of Large Nonpedunculated Colonic Adenomas : A Randomized Comparative Trial

BACKGROUND

Endoscopic resection of adenomas prevents colorectal cancer, but the optimal technique for larger lesions is controversial. Piecemeal endoscopic mucosal resection (EMR) has a low adverse event (AE) rate but a variable recurrence rate necessitating early follow-up. Endoscopic submucosal dissection (ESD) can reduce recurrence but may increase AEs.

OBJECTIVE

To compare ESD and EMR for large colonic adenomas.

DESIGN

Participant-masked, parallel-group, superiority, randomized controlled trial. (ClinicalTrials.gov: NCT03962868).

SETTING

Multicenter study involving 6 French referral centers from November 2019 to February 2021.

PARTICIPANTS

Patients with large (≥25 mm) benign colonic lesions referred for resection.

INTERVENTION

The patients were randomly assigned by computer 1:1 (stratification by lesion location and center) to ESD or EMR.

MEASUREMENTS

The primary end point was 6-month local recurrence (neoplastic tissue on endoscopic assessment and scar biopsy). The secondary end points were technical failure, en bloc R0 resection, and cumulative AEs.

RESULTS

In total, 360 patients were randomly assigned to ESD (n = 178) or EMR (n = 182). In the primary analysis set (n = 318 lesions in 318 patients), recurrence occurred after 1 of 161 ESDs (0.6%) and 8 of 157 EMRs (5.1%) (relative risk, 0.12 [95% CI, 0.01 to 0.96]). No recurrence occurred in R0-resected cases (90%) after ESD. The AEs occurred more often after ESD than EMR (35.6% vs. 24.5%, respectively; relative risk, 1.4 [CI, 1.0 to 2.0]).

LIMITATION

Procedures were performed under general anesthesia during hospitalization in accordance with the French health system.

CONCLUSION

Compared with EMR, ESD reduces the 6-month recurrence rate, obviating the need for systematic early follow-up colonoscopy at the cost of more AEs.

PRIMARY FUNDING SOURCE

French Ministry of Health.

Comparison of endoscopic submucosal resection with ligation and endoscopic submucosal dissection for small rectal neuroendocrine tumors: A multicenter retrospective study

Objectives

Endoscopic submucosal resection with band ligation (ESMR‐L) and endoscopic submucosal dissection (ESD) are both standard endoscopic resection methods for rectal neuroendocrine tumors (NETs) <10 mm in size. However, there is no definitive consensus on which is better. Here, we compared the efficacy of ESMR‐L and ESD for small rectal NETs.

Methods

This was a multicenter retrospective cohort study including 205 patients with rectal NETs who underwent ESMR‐L or ESD. Treatment outcomes were compared by univariate analysis, multivariate analysis, and inverse probability treatment weighting (IPTW) using propensity scores. Subgroup analysis evaluated the impact of the endoscopist's experience on the technical outcome.

Results

Eighty‐nine patients were treated by ESMR‐L and 116 by ESD. The R0 resection rate was not significantly different between the two (90% vs. 92%, p = 0.73). The procedure time of ESMR‐L was significantly shorter than for ESD (17 min vs. 52 min, p < 0.01) and the hospitalization period was also significantly shorter (3 days vs. 5 days, p < 0.01). These results were confirmed by multivariate analysis and also after IPTW adjustment. The procedure time of ESD was significantly prolonged by a less‐experienced endoscopist (49 min vs. 70 min, p = 0.02), but that of ESMR‐L was not affected (17 min vs. 17 min, p = 0.27).

Conclusions

For small rectal NETs, both ESMR‐L and ESD showed similar high complete resection rates. However, considering the shorter procedure time and shorter hospitalization period, ESMR‐L is the more efficient treatment method, especially for less‐experienced endoscopists.

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.

Colonoscopy quality improvement after initial training: A cross-sectional study of intensive short-term training

Background and study aims High-quality is crucial for the effectiveness of colonoscopy and can be achieved by high-quality training and verified with assessment of key performance indicators (KPIs) for colonoscopy such as cecum intubation rate (CIR), adenoma detection rate (ADR) and adequate polyp resection. Typically, trainees achieve adequate CIR after 275 procedures, but little is known about learning curves for KPIs after initial training. Methods This cross-sectional study includes work-up colonoscopies after a positive screening test with fecal occult blood testing (FIT) or sigmoidoscopy, performed by either trainees after 300 training colonoscopies or by consultants. Outcome measures were KPIs. We assessed inter-endoscopist variation in trainees and learning curves for trainees as a group. We also compared KPIs for trainees and consultants as a group.  Results Data from 6,655 colonoscopies performed by 21 trainees and 921 colonoscopies performed by 17 consultants were included. Most trainees achieved target standards for main KPIs. With time, trainees shortened cecum intubation time and withdrawal time without decreasing their ADR, reduced the proportion of painful colonoscopies, and increased the adequate polyp resection rate (all P  < 0.01). Compared to consultants, trainees had higher CIR (97.7 % vs. 96.3 %, P  = 0.02), ADR after positive FIT (57.6 % vs. 50.3 %, P  < 0.01), and proximal ADR after sigmoidoscopy screening (41.1 % vs. 29.8 %; P  < 0.01), higher adequate polyp resection rate (94.9 % vs. 93.1 %, P  = 0.01) and fewer serious adverse events (0.65 % vs. 1.41 %, P  = 0.02). Conclusions Trainees performed high-quality colonoscopies and achieved international target standards. Several KPIs continuously improved after initial training. Trainees outperformed consultants on several KPIs.

EMR combined with hybrid argon plasma coagulation to prevent recurrence of large nonpedunculated colorectal polyps (with videos)

BACKGROUND AND AIMS

EMR is the mainstay of therapy for large colorectal polyps. Local recurrence after EMR is common and can be reduced using margin ablation. Our aim was to evaluate recurrence rates when using hybrid argon plasma coagulation (h-APC) ablation after EMR.

METHODS

Adult patients (aged 18-89 years) undergoing EMR of nonpedunculated colorectal polyps ≥20 mm were enrolled in a prospective multicenter study. h-APC was used to ablate all defect margins and also the resection surface in selected cases. The primary study outcome was recurrence rates found during the first follow-up colonoscopy. Secondary outcomes were technical success and adverse event rates.

RESULTS

EMR with h-APC ablation was used in 101 polyps (84 patients, 46.4% women). EMR with h-APC ablation was technically successful in all cases (median EMR time, 15 minutes; median h-APC ablation time, 4 minutes). Median polyp size was 30 mm (range, 20-60). Resected polyps were either adenomas (68/101 [67.3%]), sessile serrated lesions (27/101 [27%]), or adenocarcinomas (6/101 [6%]). The post-EMR recurrence rate was 2.2% (2/91) (95% confidence interval, .27-7.71). All 6 patients with cancer (intramucosal cancer, 4; T1sm cancer, 2) were found to have complete eradication of the primary tumor after EMR with h-APC, and none had lymph node metastasis. Four serious adverse events occurred in 3 patients (2 delayed bleeding [2.4%], 1 abdominal pain [1.2%], and 1 microperforation [1.2%]. All serious adverse events resolved with either endoscopic or antibiotic treatment only.

CONCLUSIONS

EMR with h-APC showed a high technical success rate, low adverse event rate, and very low post-EMR recurrence rates. (Clinical trial registration number: NCT04015765.).

Sampling error in the diagnosis of colorectal cancer is associated with delay to surgery: a retrospective cohort study

BACKGROUND

Accurate histopathologic diagnosis of colorectal cancer is important for treatment decision-making and timely care. The aim of this study was to measure rates and predictors of sampling errors for biopsy specimens attained at flexible lower gastrointestinal endoscopy, and to determine whether these events lead to a delay in surgical care.

METHODS

This is a retrospective observational study of patients who underwent elective resection for colorectal adenocarcinoma between January 2007 and June 2020. Primary outcomes were proportion of incorrectly diagnosed colorectal adenocarcinomas at index endoscopy by histopathology, and time between endoscopy and surgery. Secondary outcomes were predictors of sampling error, and diagnostic yield of repeat endoscopy.

RESULTS

Sampling errors occurred in 217/962 (22.6%) flexible endoscopies for colorectal adenocarcinomas. Negative biopsies were associated with a longer median time to surgery (87.6 days, IQR 48.8-180.0) compared to true positive biopsies (64.0 days, IQR 38.0-119.0), p < 0.001. Controlling for lesion location, neoadjuvant therapy, endoscopist specialty, year, and repeat endoscopies, time to surgery remained 1.40-fold longer (p < 0.001) following sampling error. Repeat endoscopy occurred following 62/217 (28.6%) cases of sampling errors, yielding a correct diagnosis of cancer in 38/62 (61.3%) cases. On multivariable analysis, sampling errors were less likely to occur for lesions endoscopists described as suspicious for malignancy (OR 0.12, 95% CI 0.07-0.21) or simple polyps (OR 0.24, 95% CI 0.08-0.70) compared to endoscopically unresectable polyps.

CONCLUSIONS

Colorectal cancers are frequently improperly sampled, which may lead to treatment delays for these patients. When cancer is suspected, surgeons should take care to ensure timely management.

Effectiveness and safety of the different endoscopic resection methods for 10- to 20-mm nonpedunculated colorectal polyps: A systematic review and pooled analysis

BACKGROUND

We performed a systematic review and pooled analysis to assess the effectiveness and safety of different endoscopic resection methods for 10- to 20-mm nonpedunculated colorectal polyps.

METHODS

Articles in PubMed, EMBASE, and the Cochrane Library related to the common endoscopic treatment of 10- to 20-mm nonpedunculated polyps published as of April 2020 were searched. Primary outcomes were the R0 resection rate and en bloc resection rate. Secondary outcomes were safety and the recurrence rate. Meta-regression and subgroup analysis were also performed.

RESULTS

A total of 36 studies involving 3212 polyps were included in the final analysis. Overall, the effectiveness of resection methods with a submucosal uplifting effect, including endoscopic mucosal resection (EMR), cold EMR and underwater EMR (UEMR), was better than that of methods without a nonsubmucosal uplifting effect [R0 resection rate, 90% (95% confidence interval (CI) 0.81-0.94, I² = 84%) vs 82% (95% CI 0.78-0.85, I² = 0%); en bloc resection rate 85% (95% CI 0.79-0.91, I² = 83%) vs 74% (95% CI 0.47-0.94, I² = 94%)]. Regarding safety, the pooled data showed that hot resection [hot snare polypectomy, UEMR and EMR] had a higher risk of intraprocedural bleeding than cold resection [3% (95% CI 0.01-0.05, I² = 68%) vs 0% (95% CI 0-0.01, I² = 0%)], while the incidences of delayed bleeding, perforation and post-polypectomy syndrome were all low.

CONCLUSIONS

Methods with submucosal uplifting effects are more effective than those without for resecting 10- to 20-mm nonpedunculated colorectal polyps, and cold EMR is associated with a lower risk of intraprocedural bleeding than other methods. Additional research is needed to verify the advantages of these methods, especially cold EMR.

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.

Advanced Colonic Polypectomy

Advanced colonic polypectomy techniques are endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), and they aim at organ preservation with low complication rates. Main goal of endoscopic submucosal dissection (ESD) is to accomplish en-bloc resection that will subsequently allow accurate histopathological evaluation. It consists of injection, circumferential incision, and dissection of the lesion. Steps of the procedure are discussed in detail along with technological advancements.