Learning Curve for Endoscopic Submucosal Dissection With an Untutored, Prevalence-Based Approach in the United States

Predictors of residual neoplasia after noncurative (R1) endoscopic submucosal dissection of lesions in the gastrointestinal tract

BACKGROUND

Endoscopic submucosal dissection (ESD) is a minimally invasive resection technique that enables the en bloc resection of gastrointestinal lesions. Despite en bloc resection, pathological evaluation of lesions can reveal positive vertical or horizontal margins, which is referred to as R1 resection. Not all R1 lesions referred for surgical resection or endoscopic surveillance show evidence of residual tumor. We aimed to identify the predictors of residual neoplasia in patients with an R1 resection following ESD.

PATIENTS AND METHODS

All lesions resected via ESD between June 2016 and September 2021 at a tertiary referral center were retrospectively identified. Lesions with an R1 resection and adequate follow-up were eligible for inclusion. Patient, lesion, and procedural characteristics were analyzed to identify predictors of residual neoplasia.

RESULTS

Of 614 lesions, 163 (28%) had R1 resection. Of these, 56 lesions in 51 patients had complete follow-up and were included. Thirteen patients (25.5%) underwent surgical resection and the remainder underwent endoscopic surveillance. Seven (12.5%) patients had residual disease. All patients with residual disease had esophageal carcinoma. Positive deep and lateral margins, severe submucosal fibrosis, and moderate/poorly differentiated tumors were identified as significant predictors of residual neoplasia.

CONCLUSION

Most R1 lesions (87.5%) resected by ESD did not have residual disease on follow-up. Those without identified risk factors for residual disease, such as esophageal carcinoma, severe submucosal fibrosis, or both histological margin positivity, may benefit from a strategy of close endoscopic surveillance rather than referral for surgical resection.

Endoscopic submucosal dissection for early gastric cancer: A major challenge for the west

Gastric cancer (GC) is the 5th most common cancer and the 3rd most common cause of cancer mortality worldwide. Two main endoscopic resective techniques exist for early GC (EGC): Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). ESD has been widely embraced in the last decade because it allows radical en bloc resections and is associated with better outcomes, as compared to EMR. However, the lack of training opportunities and flat learning curve due to low volume of EGC cases represent major obstacles to obtain proficiency on ESD in the West. As this procedure is highly efficient for the treatment of EGC, dedicated training programs with a stepwise approach and updated guidelines for ESD embracement are needed in Western countries.

Prospective, randomized controlled study evaluating a double-balloon interventional endoscopic platform for colorectal endoscopic submucosal dissection (with video)

BACKGROUNDS AND AIMS

Endoscopic submucosal dissection (ESD) can be challenging and time-consuming. A double-balloon interventional platform (DBIP) was designed to assist with navigation, stabilization, traction, and device delivery during complex colorectal polypectomy. We compared traditional ESD (T-ESD) with DBIP-assisted ESD (DBIP-ESD) in a prospective, randomized trial.

METHODS

Patients with colorectal polyps ≥2 cm were randomly assigned (1:1) to DBIP-ESD or T-ESD. The primary study endpoint was the mean total procedure time difference between groups. Secondary endpoints were intraprocedural time points, en-bloc resection rate, procedure cost, adverse events, and 3-month assessment. A sample size of 200 subjects for ≥80% power was calculated. Interim analysis for early study termination was planned at 70% enrollment if the primary endpoint was met (P ≤ .05).

RESULTS

One hundred forty-seven patients were enrolled between February 2019 and February 2020. Seven patients dropped out, and the interim analysis was performed on 140 patients (71 DBIP-ESD, 69 T-ESD). Demographics, comorbidities, and lesion size, location, and classification were similar between groups. The mean procedure time decreased with DBIP-ESD (88.6 ± 42.7 minutes) versus T-ESD (139.5 ± 83.2 minutes; difference of ∼51 minutes [36.5%]; P < .001], with procedural savings of $610.16 (11.4%) per patient after DBIP cost. The DBIP increased dissection speed by 49.0% (15.1 ± 8.0 vs 7.7 ± 6.6 cm2/h, P < .001). En-bloc resection was superior with the addition of DBIP (97.2% vs 87.0%, P = .030). The mean navigation time with DBIP-ESD for sutured defect closure decreased by 7.7 minutes (P < .001). There were no adverse events in the DBIP-ESD group.

CONCLUSIONS

DBIP-ESD decreased the total procedure time, improved the en-bloc resection rate, and facilitated sutured defect closure, making DBIP a promising and cost-effective tool to improve colorectal ESD adoption. (Clinical trial registration number: NCT03846609.).

Learning curve for endoscopic submucosal dissection (ESD) in the United States: Large, untutored, single-operator experience

Background and study aims Endoscopic submucosal dissection (ESD) allows removal of tumors en-bloc. Western adoption of ESD has been hindered by its steep learning curve. Western data regarding ESD learning curve are limited. We analyzed the learning curve of a single endoscopist at a tertiary referral center in the United States. Patients and methods All consecutive ESDs performed by a single endoscopist at a tertiary referral center in the United States from 2015 through 2022 were identified. Descriptive statistics and CUSUM analysis were used to describe the learning curve for en-bloc, R0 resection, and resection speed. Results In our study, 503 patients with 515 lesions were included. Severe submucosal fibrosis was found in 17% of the lesions. The rates of en-bloc, R0, and curative resections were 81.9%, 71.1%, and 68.4%, respectively. CUSUM analysis showed that the learning curve plateaued at 268, 347, and 170 cases for en-bloc resection, R0 resection, and achieving a resection speed > 9 cm 2 /hr. Fibrosis significantly affected the R0 resection rate in the regression analysis (95% confidence interval 0.21-0.55). In colonic ESD curve analysis, the learning plateau was reached after 185 cases for both en-bloc and R0 resection. Conclusions Following ex-vivo training in an animal model, an untutored expert operator achieved competency in ESD between 250 and 350 procedures. Our data can inform development of future training programs in the West.

Effectiveness of Strategy-Focused Training in Colorectal Endoscopic Submucosal Dissection: A Retrospective Observational Study

BACKGROUND

Colorectal ESD, an advanced minimally invasive treatment, presents technical challenges, with globally varying training methods. We analyzed the learning curve of ESD training, emphasizing preoperative strategies, notably gravity traction, to guide ESD instructors and trainee programs.

METHOD

This retrospective study included 881 cases guided by an experienced supervisor. Six trainees received "strategy-focused" instruction. To evaluate the number of ESD experiences in steps, the following phases were classified based on ESD experiences of each trainees: Phase 0 (0-50 ESD), Phase 1 (51-100 ESD), Phase 2 (101-150 ESD), and Phase 3 (151-200 ESD). Lesion background, outcomes, and safety were compared across phases. Factors contributing to technical difficulty in early (Phase 0 and 1) and late phases (Phase 2 and 3) were identified, along with the utility of traction ESD with device assistance.

RESULT

Treatment outcomes were favorable, with 99.8% and 94.7% en bloc resection and curative resection rates, respectively. Approximately 90% self-completion rate could be achieved after experiencing about 50 cases (92.7% in Phase 1), signifying proficiency growth despite increased case difficulty. In early phases, factors such as left-sided colon, LST-NG morphology, and severe fibrosis pose challenges. In late phases, LST-NG morphology, mild and severe fibrosis remained significant. Traction-assisted ESD, utilized in 3% of cases, comprised planned (1.1%) and rescue (1.9%) methods. Planned traction aided specific lesions, while rescue traction was common in the right colon.

CONCLUSION

"Strategy-focused" ESD training consistently yields successful outcomes, effectively adapting to varying difficulty factors in different proficient stages.

Development of a novel multipoint traction device for gastric and colorectal endoscopic submucosal dissection and evaluation of its efficacy and safety

BACKGROUND

Proper traction allows safer and easier endoscopic submucosal dissection; however, single-point traction may not be sufficient. In this study we assessed the safety, efficacy, and feasibility of our newly developed multipoint traction device.

METHODS

During an ex vivo study using a Konjac training model, two experts and two trainees resected 80 mock lesions of 20-mm diameter by performing endoscopic submucosal dissection with and without multipoint traction. The primary outcome was the success rate of the procedure involving traction. The secondary outcomes were the submucosal dissection time, dissection speed, and perforation during endoscopic submucosal dissection. During the in vivo study, to clarify the initial clinical outcomes, we used data from the electronic medical record of patients at our institution who underwent gastric and colorectal endoscopic submucosal dissection, which was performed by experts with our newly developed multipoint traction device, from March to December 2022.

RESULTS

The ex vivo study indicated that all traction procedures were successful. Higher resection speeds were observed with endoscopic submucosal dissection with traction than without traction (P < 0.001). Perforations were not observed. During the first in vivo clinical study, traction was feasible during 20 gastric and colorectal endoscopic submucosal dissection procedures. No adverse events occurred.

CONCLUSIONS

Our multitraction device can increase the submucosal dissection speed and simplify endoscopic submucosal dissection techniques, thus safely reducing technical challenges. The application of this device for endoscopic submucosal dissection could lead to safer and more efficient procedures. Clinical registration UMIN Clinical Trials Registry, Japan (registration number UMIN000053384).

A multicenter, retrospective study of a through-the-needle injection-capable electrosurgical knife for endoscopic submucosal dissection

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is a technically challenging resection technique for en bloc removal of dysplastic and early cancerous GI lesions. We conducted a single-arm retrospective study evaluating the safety and efficacy of a new through-the-needle injection-capable electrosurgical knife used in upper and lower ESD procedures performed at 6 U.S. academic centers.

METHODS

Data were retrospectively collected on consecutive cases in which the new ESD knife was used. The primary efficacy endpoint was successful ESD (en bloc resection with negative margins). Secondary efficacy endpoints included en bloc resection rate, curative resection rate, median ESD time, and median dissection speed. The safety endpoint was device- or procedure-related serious adverse events.

RESULTS

ESD procedures of 581 lesions in 579 patients were reviewed, including 187 (32.2%) upper GI and 394 (67.8%) lower GI lesions. Prior treatment was reported in 283 (48.9%) patients. Successful ESD was achieved in 477 (82.1% of 581) lesions-lower for patients with versus without submucosal fibrosis (73.6% vs 87.0%, respectively; P < .001) but similar for those with versus without previous treatment (81.7% vs 82.3%, respectively; P = .848). A total of 443 (76.2% of 581) lesions met criteria for curative resection. Median ESD time was 1.0 (range, 0.1-4.5) hour. Median dissection speed was 17.1 (interquartile range, 5.3-29.8) cm2/h. Related serious adverse events were reported in 15 (2.6%) patients, including delayed hemorrhage (1.9%), perforation (0.5%), or postpolypectomy syndrome (0.2%).

CONCLUSION

A newly developed through-the-needle injection-capable ESD knife showed a good success rate and excellent safety at U.S.

CENTERS

(Clinical trial registration number: NCT04580940.).

Novel gastric endoscopic submucosal dissection training model enhances the endoscopic submucosal dissection skills of trainees: a multicenter comparative study

BACKGROUND

Endoscopic submucosal dissection (ESD) requires high endoscopic technical skills, and trainees should develop effective training methods. In collaboration with KOTOBUKI Medical, we developed the G-Master, which is a non-animal training model that can simulate various parts of gastric ESD. We aimed to clarify the usefulness of the G-Master for inexperienced ESD trainees.

METHODS

We collected data from the first 5 gastric ESD cases conducted by 15 inexperienced ESD trainees at 5 participating centers between 2018 and 2022. The participants were divided into two groups: the G-Master training and non-G-Master training groups. Outcome measurements, such as procedural speed, perforation rate, self-completion rate, and en bloc resection rate, were compared between the two groups retrospectively.

RESULTS

A total of 75 gastric ESD cases were included in this study. The G-Master training group included 25 cases performed by 5 trainees, whereas the non-G-Master training group included 50 cases performed by 10 trainees. The median procedural speed for all cases was significantly faster in the G-Master training group than in the non-G-Master training group. Moreover, the procedural speed was linearly improved from the initial to the last cases in the lower location in the G-Master training group compared with the non-G-Master training group. In addition, although there was no significant difference, the G-Master training group showed lower rates of perforation and a lesser need to transition to expert operators than the non-G-Master training group.

CONCLUSION

The G-Master could improve the ESD skills of inexperienced ESD trainees.

Randomised controlled, patient-blinded, multicentre, superiority trial to evaluate the efficacy of the line-attached sheath-type traction device for endoscopic submucosal dissection in patients with superficial gastric neoplasms

INTRODUCTION

EndoTrac is a line-attached sheath-type traction device that enables us to control the direction and the force of traction during endoscopic submucosal dissection (ESD). The efficacy of EndoTrac for gastric ESD has not been fully verified.

METHODS AND ANALYSIS

The G-Trac study is a multicentre (nine general hospitals and two university hospitals in Japan) collaborative trial assessing the efficacy of EndoTrac for gastric ESDs. Patients with superficial gastric neoplasms will be enrolled and randomly assigned to undergo either conventional ESD or EndoTrac ESD. Allocation will be stratified according to tumour location, operator experience and tumour diameter at an allocation rate of 1:1. The type of endoknife used will be confirmed before randomisation. The primary outcome, procedure time, will be compared between the groups in both intention-to-treat and per-protocol analyses using the Wilcoxon rank sum test. The efficacy-related, safety-related and device-related outcomes will be assessed in the secondary analysis. The planned sample size of the 142 patients in the two groups will enable us to detect a difference with a power of 80% by using the Wilcoxon rank sum test, assuming an effect size of 0.54, asymptotic relative efficiency of 0.864 and a two-sided type 1 error rate of 5%.

ETHICS AND DISSEMINATION

This trial was approved by the certified review board of Kobe University (22 December 2022). The results from this trial will be disseminated through peer-review journals, presentations at national and international conferences, and data sharing with other researchers.

TRIAL REGISTRATION NUMBER

jRCT1052220166.

Endorobotic submucosal dissection of rectal lesions using the single port robot DaVinci-SP: initial experience of the first 10 cases

BACKGROUND

Endoluminal surgery is increasingly recognized as a mode of treatment for colorectal neoplasms with the latest robotic single port platform Da Vinci-SP (Intuitive Surgical, Sunnyvale) facilitating submucosal dissection of benign rectal neoplasm.

METHOD

In this study, we present our initial experience with endorobotic submucosal dissection in the management of benign rectal neoplasms using the Da Vinci-SP (Intuitive Surgical, Sunnyvale) between 2020 and 2021. The primary endpoint was the successful completion of submucosal dissection.

RESULTS

During the study period, 10 patients underwent endorobotic submucosal dissection for benign rectal neoplasms. The median age of the patients was 68 (range: 59-78) years, and the mean BMI was 29.38 (range: 22.9-38.5). The mean size of the lesion was 42.3 mm (range: 20-65 mm) and was located 7.3 cm (mean) from the anal verge (range: 2-10 cm). The mean operative time was 91.3 minutes (range: 57-137 minutes). All 10 dissections were completed successfully en bloc. There were no intraoperative complications or mortality. All patients were discharged on the same day and commenced on a normal diet. Late bleeding was observed in one patient receiving anticoagulation, and one patient had urinary retention. Pathology revealed two adenocarcinomas, six tubulovillous adenomas, one tubular adenoma, and one sessile serrated adenoma. There was no recurrence in all other patients during the median follow-up of 6 months (range: 4-16 months).

CONCLUSIONS

Endorobotic submucosal dissection using a single-port robotic platform is safe and feasible for benign rectal mucosal neoplasms. The semiflexible platform offers an alternative to endoscopic submucosal dissection with favourable outcomes.

How-I-do-it: laparoscopic intragastric submucosal dissection (LISD) for gastric and gastro-oesophageal junction early lesions

PURPOSE

Laparoscopic intragastric submucosal dissection (LISD) is a novel approach to the resection of gastric lesion that are not amenable to conventional endoscopic approaches. The technique permits favourable access to lesions situated at the cardia and angular notch of the stomach, enables en-bloc resection of large areas of tissue, and can prevent the need of formal gastrectomy or oesophagectomy in selected patients.

METHODS

All cases were deemed suitable for LISD by a multidisciplinary team panel following endoscopic assessment (using white light enhancement, chromoendoscopy and magnification endoscopy) that was integrated when needed with EUS, CT scan or PET scan. The surgical technique consisted in a 3-port laparoscopic approach; after establishment of pneumoperitoneum, three gastrotomies were performed to enable port insertion into the stomach. Following establishment of stable pneumogastrium, the area of interest was identified, submucosal hyaluronic acid injection performed to provide a cushion in the plane of dissection, and the excision area was circumferentially marked with cautery. Resection was completed using cautery hook, along a plane parallel to the muscolaris propria. After the specimen was extracted in a retrieval bag, intracorporeal single layer running suture closure of gastrotomies was performed. The abdominal wall closed by layers and tap block performed along with local anaesthetic injection on skin incision. Measures were taken to ensure correct orientation of resected specimens prior to fixation.

RESULTS

During the study period that spans from 2014 and 2022, a total of 11 patients underwent LISD for limited lesions of the stomach, 10 were located at gastro-oesophageal junction and one at the angular incisura. Four patients were female, seven males. The median age was 74 (46-79) years. R0 resection rate was 54.5%. Mean operative time was 109 min with very low blood loss (10 ml). Mortality rate was 0%, no immediate major complications (Grade II-V Clavien Dindo), including haemorrhage or perforation, occurred in these cases. Two patients developed dysphagia later that was successfully treated with endoscopic balloon dilatations. Median hospital stay was 3 days and median oral intake was on day 1 post-procedural.

CONCLUSIONS

Laparoscopic intragastric submucosal dissection is shown to be a safe and effective intervention for the treatment of early gastric cancers in selected patients having undergone deemed not amenable for endoscopic submucosal resection for their technically challenging location. Its application can serve as route to avoid formal surgery and the associated morbidity.

Treatment for T1 colorectal cancers substratified by site and size: "horses for courses"

Background

Owing to advances in diagnostic technology, the diagnosis of T1 colorectal cancers (CRCs) continues to increase. However, the optimal management of T1 CRCs in the Western Hemisphere remains unclear due to limited population-based data directly comparing the efficacy of endoscopic therapy (ET) and surgical resection (SR). The purpose of this study was to report outcome data from a large Western cohort of patients who underwent ET or SR for early CRCs.

Methods

The SEER-18 database was used to identify patients with T1 CRCs diagnosed from 2004 to 2018 treated with ET or SR. Multivariable logistic regression models were employed to identify variables related to lymph node metastasis (LNM). Rates of ET and 1-year relative survival were calculated for each year. Effect of ET or SR on overall survival and cancer-specific survival was compared using Kaplan-Meier method stratified by tumor size and site.

Results

A total of 28,430 T1 CRCs patients were identified from 2004 to 2018 in US, with 22.7% undergoing ET and 77.3% undergoing SR. The incidence of T1 CRCs was 6.15 per 100,000 person-years, with male patients having a higher incidence. Left-sided colon was the most frequent location of tumors. The utilization of ET increased significantly from 2004 to 2018, with no significant change in 1-year relative survival rate. Predictors of LNM were age at diagnosis, sex, race, tumor size, histology, grade, and location. The 5-year relative survival rates were 91.4 and 95.4% for ET and SR, respectively. Subgroup analysis showed that OS and CSS were similar between ET and SR in T1N0M0 left-sided colon cancers with tumors 2 cm or less and in rectal cancers with tumors 1 cm or less.

Conclusion

Our study showed that ET was feasible and safe for patients with left-sided T1N0M0 colon cancers and tumors of 2 cm or less, as well as T1N0M0 rectal cancers and tumors of 1 cm or less. Therefore, the over- and under-use of ET should be avoided by carefully selecting patients based on tumor size and site.

Predictors of long-term outcomes of endoscopic submucosal dissection of early gastric neoplasia in the West: a multicenter study

BACKGROUND

This study aimed to determine long-term outcomes of gastric endoscopic submucosal dissection (ESD) in Western settings based on the latest Japanese indication criteria, and to examine predictors of outcomes and complications.

METHODS

Data were collected from consecutive patients undergoing gastric ESD at four participating centers from 2009 to 2021. Retrospective analysis using logistic regression and survival analysis was performed.

RESULTS

415 patients were included (mean age 71.7 years; 56.4 % male). Absolute indication criteria (2018 guideline) were met in 75.3 % of patients. Median follow-up was 52 months. Post-resection histology was adenocarcinoma, high grade dysplasia, and low grade dysplasia in 49.9 %, 22.7 %, and 17.1 %, respectively. Perforation, early and delayed bleeding occurred in 2.4 %, 4.3 %, and 3.4 %, respectively. Rates of en bloc and R0 resection, and recurrence on first endoscopic follow-up were 94.7 %, 83.4 %, and 2.7 %, respectively. Relative indication (2018 guideline) for ESD was associated with R1 outcome (P = 0.02). Distal location (P = 0.002) and increased procedure time (P = 0.04) were associated with bleeding, and scarring (P = 0.009) and increased procedure duration (P = 0.003) were associated with perforation. Recurrence-free survival at 2 and 5 years was 94 % and 83 %, respectively.

CONCLUSION

This is the largest Western multicenter cohort and suggests that gastric ESD is safe and effective in the Western setting. A quarter of patients fell outside the new absolute indications for ESD, suggesting that Western practice involves more advanced lesions. We identified the predictors of complications, which should help to inform future Western practice and research.

Settings of a novel electrosurgical generator to enable efficient and safe submucosal endoscopic procedures

Background and study aims A novel electrosurgical generator unit (ESU), ConMed Beamer, was recently introduced to facilitate endoscopic submucosal dissection (ESD) by employing Automatic Cutting Effect (ACE) technology. Its use in submucosal endoscopy has yet to be investigated. The aim of this study was to evaluate the feasibility and safety of performing ESD and peroral endoscopic myotomy (POEM) using novel settings generated with ConMed Beamer ESU. Patients and methods This was a single-center prospective study of 59 consecutive patients undergoing ESD/POEM at a tertiary referral center. ESU settings were initially generated by testing in live animal models prior to first in-human study. The primary outcome was technical success. Secondary outcomes were procedure times, rate of en bloc/R0 resection, and rate of adverse events (AEs). Results A total of 44 patients (50 polyps) and 15 patients underwent ESD and POEM, respectively. En bloc resection, R0 resection, and curative resection rates were 90%, 77.1%, and 70.8%, respectively. Mean maximal length of the lesion was 3.07 cm ± 1.43 with an average dissection speed of 14.2 cm 2 /hr ± 11.1. Technical success was achieved in 100% of POEM patients. Mean time (minutes) to complete the POEM procedure was 50.1 min ± 12.4. Two major AEs occurred among all patients (3.4%). All intraprocedural bleeding events were controlled using the ConMed Beamer ESU. Conclusions ConMed Beamer ESU settings generated from this study were proven safe and effective in a prospective cohort of patients who underwent submucosal endoscopic procedures. This novel ESU can be added to the armamentarium of ESD capable generators.

Effects of traction methods in inexperienced endoscopists during colorectal endoscopic submucosal dissection

BACKGROUND

colorectal endoscopic submucosal dissection (ESD) remains a technical challenge, but traction devices show promise in making this procedure easier. However, the efficacy of traction techniques for colorectal ESD is still unknown for inexperienced endoscopists.

METHODS

We selected 400 patients who underwent colorectal ESD performed by four inexperienced endoscopists. Each patient in the traction-assisted ESD (TA-ESD) group was matched to a patient in the conventional ESD (C-ESD) group according to propensity scores.

RESULTS

One-to-one propensity score-matching analysis created 87 matched pairs. The self-completion rate in the TA-ESD group is significantly higher than that in the C-ESD group (100% [87/87] vs. 92% [80/87], p < 0.001). The median resection speed was significantly faster in the TA-ESD group than that in the C-ESD group (27 mm2/min [IQR, 19.5-47.3] vs.18 mm2/min [IQR, 13.5-33.8], p < 0.001) and the procedure time in the TA-ESD group was significantly shorter than that in the C-ESD group (33 min [IQR, 27-47] vs.53 min [IQR, 38-73], p < 0.001). However, the histologic complete resection rate was not significantly different between the TA-ESD and C-ESD groups (93.1% [6/87]) vs. 96.6% [3/87], p < 0.1888, respectively). The en bloc resection rate (96.6%) and perforation rate (4.6%) were equivalent between the TA-ESD group and the C-ESD group.

CONCLUSION

Traction techniques seem to improve resection speed and self-completion rate of colorectal ESD for inexperienced endoscopists.

Safety and feasibility of same-day discharge after endoscopic submucosal dissection: a Western multicenter prospective cohort study

BACKGROUND AND AIMS

Recent Western studies support the safety and efficacy of endoscopic submucosal dissection (ESD) for lesions throughout the GI tract. Although admission for observation after ESD is standard in Asia, a more selective approach may optimize resource utilization. We aimed to evaluate the safety and feasibility of same-day discharge (SDD) after ESD and factors associated with admission.

METHODS

This was a post hoc analysis of a multicenter, prospective cohort of patients undergoing ESD (2016-2021). The primary end points were safety of SDD and factors associated with post-ESD admission.

RESULTS

Of 831 patients (median age, 67 years; 57% male) undergoing 831 ESDs (240 performed in the esophagus, 126 in the stomach, and 465 in the colorectum; median lesion size, 44 mm), 588 (71%) were SDD versus 243 (29%) admissions. Delayed bleeding and perforation occurred in 12 (2%) and 4 (.7%) of SDD patients, respectively; only 1 (.2%) required surgery. Of the 243 admissions, 223 (92%) were discharged after ≤24 hours of observation. Interestingly, larger lesion size (>44 mm) was not associated with higher admission rate (odds ratio [OR], .5; 95% confidence interval [CI], .3-.8; P = .001). Lesions in the upper GI tract versus colon (OR, 1.7; 95% CI, 1.1-2.6; P = .01), invasive cancer (OR, 1.9; 95% CI, 1.2-3.1; P = .01), and adverse events (OR, 2.7; 95% CI, 1.5-4.8; P = .001) were independent factors for admission. Admissions were more likely performed by endoscopists with ESD volume <50 cases (OR, 2.1; 95% CI, 1.3-3.3; P = .001) with procedure time >75 minutes (OR, 13.5; 95% CI, 8.5-21.3; P < .0001).

CONCLUSIONS

SDD after ESD can be safe and feasible. Patients with invasive cancer, lesions in the upper GI tract, longer procedure times, or procedures performed by low-volume ESD endoscopists are more likely to be admitted postprocedure. Risk stratification of patients for SDD after ESD should help optimize resource utilization and enhance ESD uptake in the West. (Clinical trial registration number: NCT02989818.).

LEARNING CURVE IN ESOPHAGEAL ENDOSCOPIC SUBMUCOSAL DISSECTION BY WESTERN ENDOSCOSPISTS TRAINED IN JAPAN: EXPERIENCE IN LATIN AMERICA

•This study aimed to assess the learning curve effect on patient's clinical outcome for EESD. Retrospective observational study, enrolling patients that underwent EESD from 2009 to 2021, divided in 2 groups. Mean procedure time was 111.8 min and 103.6 min for T1 and T2, respectively (P=0.004). The learning curve in esophageal ESD could be overcomed effectively and safely by an adequately trained Western endoscopist. Background - Esophageal endoscopic submucosal dissection (EESD) is a complex and time-consuming procedure at which training are mainly available in Japan. There is a paucity of data concerning the learning curve to master EESD by Western endoscopists. Objective - This study aimed to assess the learning curve effect on patient's clinical outcome for EESD. Methods - This is a retrospective observational study. Enrolling patients that underwent EESD from 2009 to 2021. The analysis was divided into two periods; T1: case 1 to 49 and T2: case 50 to 98. The following features were analyzed for each group: patients and tumors characteristics, en-bloc, complete and curative resection rates, procedure duration and adverse events rate. Results - Ninety-eight EESD procedures were performed. Mean procedure time was 111.8 min and 103.6 min for T1 and T2, respectively (P=0.004). En bloc resection rate was 93.8% and 97.9% for T1 and T2, respectively (P=0.307). Complete resection rate was 79.5% and 85.7% for T1 and T2, respectively (P=0.424). Curative resection rate was 65.3% and 71.4% for T1 and T2, respectively (P=0.258). Four patients had complications; three during T1 period and one during T2 period. Overall mortality rate: 0%. Conclusion - The esophageal endoscopic submucosal dissection could be performed effectively and safely by an adequately trained Western endoscopist.

East versus West: Comparisons and Implications in Adaptation to Practice

Endoscopic submucosal dissection (ESD) is the preferred strategy for the resection of large superficial neoplasia throughout the gastrointestinal tract in Asian countries. The transition of ESD to the West has been slower because of various regional and training differences. Nonetheless, over the past couple of decades, the steady growth of ESD mentors in the West and the introduction of viable training pathways and dedicated devices and accessories have led to the increasing adoption of ESD and other third space endoscopic procedures.

Training in Endoscopic Submucosal Dissection in the United States: The Current Paradigm

Endoscopic submucosal dissection (ESD) training in Japan is pursued through a designated master-apprentice, organ-based stepwise training model. However, applying a similar program to the United States is not a practical strategy due to the significant differences in the training system and disease prevalence. To incorporate the ESD training into the current advanced endoscopy fellowship program, the use of recently developed techniques and technologies to improve the efficiency of ESD is ideal. The ESD training program in the United States should be prevalence-based, with increased involvement of trainees depending on their objectively assessed competency levels.

Resection speed of endoscopic submucosal dissection according to the location of gastric neoplasia: a learning curve using cumulative sum analysis

BACKGROUND

There is few study evaluating the relationship between endoscopic submucosal dissection (ESD) resection speed and the lesion characteristics of gastric neoplasia. We investigated the learning curve of consecutive ESDs using cumulative sum (CUSUM) analysis.

METHODS

A total of 356 ESDs performed by a single endoscopist were grouped chronologically into three learning periods. The ESD procedure was defined to be fast when resection speed was > 9.0 cm²/hour. The CUSUM method was used to assess the number of ESDs required for achieving proficiency and mastery.

RESULTS

Mean resection speed was significantly faster in Phase III (15.1 cm²/hour) compared to those in Phase I (9.3 cm²/hour) and II (11.4 cm²/hour) (p < 0.001). Tumors in the stomach's upper and middle third location were significantly associated with difficulty in attaining the fast resection speed (odds ratios, 0.05 and 0.36) compared to the lower third location. The number of ESDs required to achieve a competency for fast resection was 15 for tumors in the lower third of the stomach and 98 for those in the upper/middle third location, respectively. In the lower third location of the tumor, the CUSUM curve revealed that 75 cases were needed to achieve proficiency and 174 cases to achieve mastery. However, mastery was not achieved in ESD for the upper/middle third tumor during the study period.

CONCLUSION

The time required to achieve relevant competency in gastric ESD depends on the tumor location.

Comparison of efficiency and safety between dual-clip and rubber band-assisted ESD and conventional ESD for colonic lateral spreading tumors (LSTs) with different levels of technical difficulty: a retrospective case–control study

Background

Dual-clip and rubber band-assisted endoscopic submucosal dissection (DCRB-ESD) is a useful technique in the management of lateral spreading tumors (LSTs) of the colon and is suggested by researchers compared with conventional ESD (C-ESD). The aim of this retrospective study is to further analyze the efficiency and safety of DCRB-ESD in a setting with varying technical difficulties.

Methods

Patients who underwent endoscopic treatment (DCRB-ESD or C-ESD) due to LSTs between Jan 1st, 2019 and Jan 1st, 2022, were retrospectively collected. Patients were classified into the following two groups: the DCRB-ESD group (n = 46) and the C-ESD group (n = 81). Baselines were compared and propensity score matching (PSM) was employed to manage the heterogeneity. The technical difficulty and outcomes of the two groups were evaluated based on a semiquantitative model (CS-CRESD) previously described.

Results

The baseline characteristics of the two groups were balanced except sex and LST classification before PSM and were corrected after PSM. The median ESD operation time of DCRB-ESD was shorter than that of C-ESD (32 vs 41 and 30 vs 44 before and after PSM respectively, P < 0.05). The operation durations of cases with different CS-CRESD scores were different (P < 0.05). In the subgroup with a score of 0, DCRB-ESD showed no advantage than C-ESD in terms of operation duration before and after PSM. In subgroups with a score of 1–3, DCRB-ESD was faster than C-ESD. In subgroups with a score of 4–5, the between-group operation duration was not significantly different due to the limited number of cases, although the median time of DCRB-ESD was shorter. The R0 resection rates, curative resection, complications, and additional surgery in both groups were not significantly different. No adverse events, such as a clip falling off or rubber band rupturing occurred during this study.

Conclusion

DCRB-ESD was an efficient and safe procedure in the management of colonic LSTs. With DCRB-ESD, the operation duration of difficult cases can be shortened without sacrificing complication risk. However, not all cases would benefit from DCRB-ESD. For easy cases (CS-CRESD score = 0), DCRB-ESD may not be prior to C-ESD by experienced endoscopists. A pre-ESD technical difficulty evaluation was recommended to decide whether to perform DCRB-ESD or not.

Underwater Versus Conventional Endoscopic Mucosal Resection for Superficial Non-ampullary Duodenal Epithelial Tumors: A Systematic Review and Meta-Analysis

BACKGROUND/AIMS

Duodenal underwater endoscopic mucosal resection (UEMR) has been suggested as a feasible treatment option for superficial non-ampullary duodenal epithelial tumors (SNADETs). However, its efficacy and safety have not been fully established yet. Thus, the objective of this systematic review and meta-analysis was to determine the efficacy and safety of UEMR as compared with conventional endoscopic mucosal resection (CEMR) in the treatment of SNADETs.

METHODS

We conducted a comprehensive literature search in PubMed, EMBASE, the Cochrane Library. Studies comparing CEMR and UEMR for the resection of SNADET were included. Outcomes included en-bloc and complete resection rates, adverse events, and procedure time.

RESULTS

A total of six studies with 2454 lesions were included in the quantitative synthesis. En-bloc and complete resection rates were not significantly different between UEMR and CEMR (OR for en-bloc resection: 0.997 [95% CI 0.439-2.266]; OR for complete resection: 0.960 [95% CI 0.628-1.468]). There was no significant risk difference for perforation (risk difference: - 0.002; 95% CI - 0.009 to 0.005) or delayed bleeding (risk difference: - 0.001; 95% CI - 0.014 to 0.011). Procedure time was significantly shorter in the UEMR (standardized mean difference: - 1.294; 95% CI - 2.461 to - 0.127). The risk of recurrence was not significantly different between UEMR and CEMR (risk difference: 0.001; 95% CI - 0.041 to 0.044).

CONCLUSION

Although our results did not show any superiority of UEMR over CEMR in the treatment of SNADETs, UEMR showed equivalent efficacy and safety as compared with CEMR and was associated with a shorter procedure time.

Learning curve of endoscopic submucosal dissection (ESD) with prevalence-based indication in unsupervised Western settings: a retrospective multicenter analysis

BACKGROUND AND AIMS

As there is still no consensus about the adequate training strategy for ESD in Western countries, we evaluated unsupervised prevalence-based learning curves including detailed organ-specific subgroup analysis.

METHODS

The first 120 ESDs of four operators (n = 480) were divided into three groups (1: ESD 1-40, 2: ESD 41-80, 3: ESD 81-120). Outcome parameters were rates of technical success, en bloc and R0 resection, the resection speed, rates of conversion to EMR, curative resection, adverse events, surgery due to adverse events, and recurrence. In addition, we analyzed the achievement of quality benchmarks indicating levels of expertise.

RESULTS

After exclusion of pretreated lesions, 438 procedures were enrolled in the final analysis. Technical success rates were > 96% with significant improvements regarding rate of en bloc resection (from 82.6 to 91.2%), resection speed (from 4.54 to 7.63 cm²/h), and rate of conversion to EMR (from 22.0 to 8.1%). No significant differences could be observed for rates of R0 resection (65.9 vs. 69.6%), curative resection (55.8 vs. 55.7%), adverse events (16.3 vs. 11.7%), surgery due to adverse events (1.5 vs. 1.3%), and recurrence (12.5 vs. 4.5%). Subgroup and benchmark analysis revealed an improvement in esophageal, gastric, and rectal ESD with achievement of competence levels for the esophagus and stomach within 80 and most of the benchmarks for proficiency level within 120 procedures. Some of the benchmarks could also be achieved in rectal ESD.

CONCLUSIONS

This trial confirms safety and feasibility of unsupervised ESD along the initial learning curve with prevalence-based indication and exclusion of colonic cases.

Development of new gastric endoscopic submucosal dissection training model: A reproducibility evaluation study

Background and study aims  Gastric endoscopic submucosal dissection (ESD) is a highly technical procedure mainly due to the distinctive shape of the stomach and diverse locations of lesions. We developed a new gastric ESD training model (G-Master) that could accurately recreate the location of the stomach and assessed the reproducibility of located lesions in the model. Methods  The model comprises a simulated mucous membrane sheet made of konjac flour and a setting frame, which can simulate 11 locations of the stomach. We assessed the reproducibility of each location in the model by assessing the procedure speed and using a questionnaire that was distributed among experts. In the questionnaire, each location was scored on a six-point scale for similarity of locations. Results  The mean score for all locations was high with > 4 points. Regarding locations, lower anterior and posterior walls had medium scores with 3 to 4 points. The procedure speed was slower in the greater curvature of the upper and middle gastric portions, where ESD is considered more difficult than the overall procedure speed. Conclusions  The new gastric ESD training model appears to be highly reproducible for each gastric location and its application for training in assuming actual gastric ESD locations.

Squamous Cell Carcinoma of the Esophagus

Esophageal squamous cell carcinoma (ESCC) is common in the developing world with decreasing incidence in developed countries and carries significant morbidity and mortality. Major risk factors for ESCC development include significant use of alcohol and tobacco. Screening for ESCC can be recommended in high-risk populations living in highly endemic regions. The treatment of ESCC ranges from endoscopic resection therapy or surgery in localized disease to chemoradiotherapy in metastatic disease, and prognosis is directly related to the stage at diagnosis. New immunotherapies and molecular targeted therapies may improve the dismal survival outcomes in patients with metastatic ESCC.

Advanced Endoscopic Resection Techniques: Endoscopic Submucosal Dissection and Endoscopic Full-Thickness Resection

Endoscopic resection is first-line therapy in the management of superficial neoplasms throughout the gastrointestinal tract, as well as an increasingly viable therapeutic alternative in the resection of selected small deep lesions throughout the upper and lower gastrointestinal tract. The mainstay of therapy has traditionally been endoscopic snare polypectomy and endoscopic mucosal resection. However, recent innovative advancements in therapeutic endoscopy have provided for the ability to resect large superficial lesions and selected subepithelial lesions in en bloc and margin-negative fashion. In this review, we discuss the current state of the art in advanced endoscopic resection techniques including endoscopic submucosal dissection and endoscopic full-thickness resection.

Performance of perioperative antibiotics against post-endoscopic submucosal dissection coagulation syndrome: a multicenter randomized controlled trial

BACKGROUND AND AIMS

This study aimed to evaluate the efficacy of perioperative antibiotics against post-endoscopic submucosal dissection (ESD) coagulation syndrome (PECS) in patients undergoing colorectal ESD.

METHODS

A prospective, multicenter, randomized controlled, parallel, superiority trial was conducted at 21 Japanese tertiary institutions. Patients with superficial colorectal lesions ≥20 mm and those undergoing ESD management for a single lesion were eligible. Patients with perforation during and after ESD were withdrawn. Before the ESD procedure, participants were randomly assigned (1:1) to either undergo conventional treatment (nonantibiotic group) or investigational treatment (antibiotic group). In the antibiotic group, 3 g of ampicillin-sulbactam was administered just before, 8 hours after, and the morning after ESD. The primary endpoint was the incidence of PECS. The onset of PECS was defined as localized abdominal pain (both spontaneous pain and tenderness) and fever (≥37.6°C) or inflammatory response (leukocytosis [≥10,000 cells/μL] or elevated C-reactive protein level [≥.5 mg/dL]).

RESULTS

From February 5, 2019 to September 7, 2020, 432 patients were enrolled and assigned to the antibiotic group (n = 216) or nonantibiotic group (n = 216). After withdrawal of 52 patients, 192 in the antibiotic group and 188 in the nonantibiotic group were analyzed. PECS occurred in 9 of 192 patients (4.7%) in the antibiotic group and 14 of 188 patients (7.5%) in the nonantibiotic group, with an odds ratio of .61 (95% confidence interval, .23-1.56; P = .29).

CONCLUSIONS

Perioperative use of antibiotics was not effective in reducing the incidence of PECS in patients undergoing colorectal ESD. (Clinical trial registration number: UMIN000035178.).

Multi-loop traction device facilitates gastric endoscopic submucosal dissection: ex vivo pilot study and an inaugural clinical experience

BACKGROUND

Endoscopic submucosal dissection (ESD) is technically difficult and requires considerable training. The authors have developed a multi-loop traction device (MLTD), a new traction device that offers easy attachment and detachment. We aimed to evaluate the utility of MLTD in ESD.

METHODS

This ex vivo pilot study was a prospective, block-randomized, comparative study of a porcine stomach model. Twenty-four lesions were assigned to a group that undertook ESD using the MLTD (M-ESD group) and a group that undertook conventional ESD (C-ESD group) to compare the speed of submucosal dissection. In addition, the data of consecutive 10 patients with eleven gastric lesions was collected using electronic medical records to clarify the inaugural clinical outcomes of gastric ESD using MLTD.

RESULTS

The median (interquartile range) speed of submucosal dissection in the M-ESD and C-ESD groups were 141.5 (60.9-177.6) mm2/min and 35.5 (20.8-52.3) mm2/min, respectively; submucosal dissection was significantly faster in the M-ESD group (p < 0.05). The rate of en bloc resection and R0 resection was 100% in both groups, and there were no perforation in either group. The MLTD attachment time was 2.5 ± 0.9 min and the MLTD extraction time was 1.0 ± 1.1 min. Clinical outcomes of MLTD in gastric ESD were almost the same as those of ex vivo pilot study.

CONCLUSIONS

MLTD increased the speed of submucosal dissection in ESD and was similarly effective when used by expert and trainee endoscopists without perforation. MLTD can potentially ensure a safer and faster ESD.

The learning experience for endoscopic submucosal dissection in a non-academic western hospital: a single operator's untutored, prevalence-based approach

Background

Studies of learning experience in endoscopic submucosal dissection (ESD) commonly originate from the East. Little is known about the performance of ESD in low-volume western centers. Furthermore, it is unclear whether ESD can be self-taught without a tutored approach.

Methods

We performed a retrospective analysis of consecutive ESDs, performed in an untutored prevalence-based fashion by a single operator at a private Greek hospital from 2016-2020. Out of 60 lesions, standard ESD was applied for 54 and enucleation for 6; 41 were mucosal and 19 submucosal; 3 esophageal, 24 gastric, one duodenal, 12 colonic, and 20 rectal.

Results

Pathology revealed carcinoma (n=14), neuroendocrine tumor (n=7), precancerous lesion (n=27), or other submucosal tumors (n=12). The rates of en bloc and R0 resection were 98% and 91%, respectively. The median resection speed was <3 cm²/h for the first 20 cases, but improved progressively to ≥9 cm²/h after 40 cases. Two patients underwent laparoscopic surgery for colonic perforation, and one received a blood transfusion because of delayed bleeding (serious adverse event rate: 5%). No deaths occurred. The median hospital stay was 1.3 days. Variables associated with improvement in ESD speed during the second period of the study were the application of countertraction and the experience acquired through other endosurgical techniques.

Conclusions

ESD was safe and effective in a low-volume center, with an acceptable adverse events rate. At least 40 mixed cases were needed to achieve a high resection speed. Additive experience gained through other endosurgical procedures probably contributed to the improvement in performance.

The learning curve for transoral incisionless fundoplication

Background and study aims  Transoral incisionless fundoplication (TIF) is a safe and effective minimally invasive endoscopic technique for treating gastroesophageal reflux disease (GERD). The learning curve for this technique has not been reported. We studied the learning curve for TIF when performed by a gastroenterologist by identifying the threshold number of procedures needed to achieve consistent technical success or proficiency (consistent creation of TIF valve ≥ 270 degrees in circumference, ≥ 2 cm long) and efficiency after didactic, hands-on and case observation experience. Patients and methods  We analyzed prospectively collected data from patients who had TIF performed by a single therapeutic endoscopist within 17 months after basic training. We determined thresholds for procedural learning using cumulative sum of means (CUSUM) analysis to detect changes in achievement rates over time. We used breakpoint analysis to calculate procedure metrics related to proficiency and efficiency. Results  A total of 69 patients had 72 TIFs. The most common indications were refractory GERD (44.7 %) and proton pump inhbitor intolerance (23.6 %). Proficiency was achieved at the 18 ^th to 20 ^th procedure. The maximum efficiency for performing a plication was achieved after the 26 ^th procedure, when mean time per plication decreased to 2.7 from 5.1 minutes (P < 0.0001). TIF procedures time varied until the 44 ^th procedure, after which it decreased significantly from 53.7 minutes to 39.4 minutes (P < 0.0001). Conclusions  TIF can be safely, successfully, and efficiently performed in the endoscopy suite by a therapeutic endoscopist. The TIF learning curve is steep but proficiency can be achieved after a basic training experience and 18 to 20 independently performed procedures.

Assessment of tumor extension to the ductal system of submucosal glands in patients with superficial esophageal squamous neoplasms: Implications for endoscopic resection

BACKGROUND

Endoscopic submucosal dissection (ESD) has become the standard treatment for superficial esophageal squamous cell neoplasia (SESCN); however, local recurrence still occurs occasionally even in patients who meet the current curative criteria. Esophageal ducts of the submucosal gland may serve as a pathway for the spread of SESCN to a deeper layer. However, the clinical impact of ductal involvement (DI) in patients undergoing ESD has yet to be investigated.

METHODS

We consecutively enrolled patients with SESCN who were treated with ESD. The resected specimens were meticulously reviewed in multiple section slices for the presence and resected margins of DI, and their correlations with clinical factors were evaluated.

RESULTS

A total of 210 lesions were analyzed, of which 78 (37.1%) presented with DI. The presence of submucosal invasion, lymphovascular invasion (LVI), and DI were indicators of worse prognosis (P < .05). Deep extended DIs were misdiagnosed as deep submucosal invasive cancer in 4 cases (2%). Of the 185 patients who met the criteria for curative ESD (ie, R0 resection and no deep submucosal invasion or LVI), 11 (5.9%) developed local recurrence/metastasis during a mean follow-up of 55.2 months (range, 6 to 140) months. Compared with patients with without DI, patients with DI had worse recurrence-free survival (P = .008, log-rank test) and a higher local risk of recurrence (12.7% vs 2.5%) after curative ESD (hazard ratio, 4.20; P = .038).

CONCLUSIONS

A precise histological assessment of DI in SESCN is crucial after ESD, given that DI is common and associated with worse outcome. Whether total removal of esophageal glands/ducts can improve outcome requires future study.

Prediction of technically difficult endoscopic submucosal dissection for large superficial colorectal tumors: a novel clinical score model

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is a promising technique for removing superficial GI tumors, but ESD is technically difficult. The aim of this study was to establish a clinical score model for grading technically difficult colorectal ESD.

METHODS

Data on patients, lesions, and outcomes of colorectal ESD at 2 centers were analyzed. The objective parameter of successful ESD within 60 minutes was set as an endpoint to evaluate the difficulty. Independent predictors of difficulty in the derivation cohort were identified by multiple logistic regression analysis and used to develop a clinical score. We validated the score model in the validation cohort.

RESULTS

The clinical score comprised tumor size of 30 to 50 mm (1 point) or ≥50 mm (2 points), at least two-thirds circumference of the lesion (2 points), location in the cecum (1 point), flexure (2 points) or dentate line (1 point), and laterally spreading tumor nongranular lesions (1 point). Areas under the receiver operator characteristic curves for the score model were comparable (derivation [.70] vs internal validation [.69] vs external validation [.69]). The probability of successful ESD within 60 minutes in easy (score = 0), intermediate (score = 1), difficult (score = 2-3), and very difficult (score ≥4) categories were 75.0%, 51.3%, 35.6%, and 3.4% in the derivation cohort; 73.3%, 47.9%, 31.8%, and 16.7% in the internal validation cohort; and 79.5%, 66.7%, 43.3%, and 20.0% in the external validation cohort, respectively.

CONCLUSIONS

This clinical score model accurately predicts the probability of successful ESD within 60 minutes and can be applied to grade the technical difficulty before the procedure.

Endoscopic management of Barrett's esophagus: Western perspective of current status and future prospects

Barrett's esophagus (BE) is a precursor to esophageal adenocarcinoma and current practice is to establish endoscopic surveillance once diagnosed, in order to identify early dysplasia and neoplasia that has the potential to undergo endoscopic eradication therapy (EET). Before embarking upon EET the clinical team has a duty to consider all viable options and come to a plan based on recent evidence. The therapeutic approach varies greatly but largely adheres to the mantra of 'Detect-Resect-Ablate', in which high-quality endoscopy identifies BE associated pathology, associated lesions (if present) undergo safe endoscopic resection and remaining intestinal metaplasia in the esophagus is ablated to prevent recurrence of dysplasia. In this review, current practice, pitfalls, complications, and the future perspectives on practice in this field are discussed. The Western perspective is focused on here, with an outline of the differences in clinical practice with Asian nations and attempts to bridge these differences.

Learning curve for endoscopic submucosal dissection of early colorectal neoplasms with a monopolar scissor-type knife: use of the cumulative sum method

OBJECTIVE

Although scissor-type knives such as the Stag-Beetle (SB) Knife Jr are expected to result in a safe and easy colorectal endoscopic submucosal dissection (CR-ESD), information regarding the learning curve is lacking. Therefore, this study evaluated the learning curve with using SB Knife Jr.

MATERIALS AND METHODS

We retrospectively reviewed 507 CR-ESD procedures performed in 464 patients using SB Knife Jr. The primary endpoint was a learning curve to achieve a satisfactory complete resection rate. The secondary endpoints were learning curves to achieve a satisfactory en bloc resection rate, curative resection rate, and resection speed.

RESULTS

The complete, en bloc, and curative resection rates were 91.9%, 95.9%, and 84.0%, respectively. Moving average analysis showed that 39 cases were required for a complete resection rate of >80%, 41 for an en bloc resection rate of >90%, and 50 for a curative resection rate of >75%. We divided the procedure into three phases using the cumulative sum method: I, II, and III (cases 1-36, 37-119, and 120-507, respectively). Although we found no significant between-phase differences, the complete resection rate showed an increasing trend in Phase III (83.3 vs. 89.2 vs. 93.3%; p = .099). The en bloc resection rate (91.7 vs. 91.6 vs. 97.2%; p = .047) and resection speed (20.5 vs. 7.2 vs. 6.8 min/cm²; p < .001) were greater in Phase III. Despite the larger specimen size (27.3 vs. 38.2 vs. 40.4 mm; p < .001) and more severe fibrosis (p < .001) in Phase III, the procedure time was shorter (73.8 vs. 57.8 vs. 54.2 min; p = .041). The curative resection rate was not significantly different between phases.

CONCLUSIONS

SB Knife Jr enables safe and easy CR-ESD during the introductory period compared to the conventional tip-type knife and has an acceptable learning curve. Therefore, using this knife will encourage the widespread adoption of CR-ESD in Asian general hospitals and non-Asian countries.

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.

Current state of education and training for endoscopic submucosal dissection: Translating strategy and success to the USA

Endoscopic submucosal dissection (ESD) is a rigorous and technically sophisticated method for removal of lesions within the gastrointestinal tract. Despite having advantages of en-bloc resection of lesions, regardless of size, and widespread use in Japan and Asia, ESD has not become widely adopted in the USA for a variety of reasons. Based upon Japanese education and the master-apprentice model, modification to the education system and additional techniques designed to facilitate broader adoption are required for trainees in the USA. This article will review the current state of education and training for ESD in the USA.