Untutored learning curve to establish endoscopic submucosal dissection on competence level

Endoscopic resection of gastrointestinal tumors: Training levels and professional roles explored

In this editorial, we provide commentary on a recently published study by Zhao et al in the World Journal of Gastrointestinal Oncology. The study discusses the clinical characteristics of patients undergoing endoscopic resection for gastric cancers. We feel it is important to engage our endoscopy community in a discussion on the current evidence in the literature on the necessary number of cases for training in endoluminal surgery techniques, particularly endoscopic submucosal dissection. This includes the latest recommendations from the European Society of Gastrointestinal Endoscopy, as well as a summary of key studies on the learning curve for these techniques. Additionally, we explore the impact of an endoscopist's specialty on endoscopy outcomes, drawing from current evidence in the literature to shape our perspective in this evolving field.

Learning curve of colorectal endoscopic submucosal dissection of an endoscopist experienced hands-on training in Japan

BACKGROUND AND AIM

Colorectal endoscopic submucosal dissection is a technically demanding procedure with a steep learning curve. In Japan, the National Cancer Center Hospital allows overseas doctors to participate in hands-on training. We aimed to assess the colorectal endoscopic submucosal dissection performance and learning curve of an endoscopist who participated in hands-on training.

METHODS

In this retrospective analysis using a prospectively collected database, 100 consecutive superficial colorectal tumors from 100 patients treated with endoscopic submucosal dissection by a colorectal surgeon between January 2020 and May 2024 were included. The cases were grouped into three learning periods: phase I (the initial 30 cases under local expert supervision before training in Japan), phase II (the middle 30 cases), and phase III (the last 40 cases). The primary outcome was resection speed.

RESULTS

The median resection speed was 5, 11.7, and 13.2 cm2/h in phases I, II, and III, respectively. In matched data, the resection speeds in phases II and III were higher than that in phase I (P = 0.02 and P < 0.001, respectively). En bloc and R0 resection rates were 99% and 95%, respectively. The en bloc resection, R0 resection, and complication rates were not different between phases. Cumulative sum analysis of the resection speed revealed that proficiency was achieved after 36 cases.

CONCLUSIONS

An endoscopist who underwent a tutored approach and hands-on training in Japan achieved the proficiency benchmarks for colorectal endoscopic submucosal dissection after 36 cases. However, the endoscopist's extensive experience before training may contribute to excellent outcomes.

Clinical audit of endoscopic sub-mucosal dissection performed for complex lateral spreading colorectal tumors from a region non-endemic for colorectal cancer

BACKGROUND

Endoscopic resection is currently the treatment of choice for laterally spreading tumors (LSTs). Endoscopic sub-mucosal dissection (ESD) can achieve higher enbloc resection and R0 resection, albeit at a slightly higher risk of complications. Given scarce data on ESD from India, we performed a retrospective analysis of our experience with colorectal ESD (CR-ESD) to know its clinical efficacy and complications as well as to assess the learning curve of CR-ESD in non-endemic-areas.

METHODS

Retrospective analysis of prospectively maintained datasheet performed. All patients with large (>2cm), complex or recurrent colorectal LST who underwent ESD at our center between 2012 and 2021 were included in the study. Various baseline lesion-related parameters, procedure-related parameters, enbloc resection (ER) rates, R0 margins and adverse event rates were retrieved. CUSUM analysis was performed to calculate the minimum required procedures to achieve competency in CR-ESD.

RESULTS

Total 149 patients were included in the study; mean patient age was 61.36±18.21 years. Most patients had lesions in rectum (n=102; 68.5%) followed by sigmoid colon (n=25; 16.8%). The mean lesion size was 46.62 ± 25.46 mm and the mean procedure duration for ESD was 219.30 ± 150.05 min. ER was achieved in 94.6% of lesions. R0 resection was achieved in 132 patients (88.6%). Overall, six (4%) adverse events were noted, of which one required surgical intervention. As many as 105 patients (70.5%) had adenomatous lesions on histology. Seventy-four patients underwent follow-up colonoscopy, of which three had a recurrence of adenomatous lesions and five had post-resection stricture requiring endoscopic dilation. CUSUM curve analysis calculated the learning curve for ESD was 47 resections for ER and 55 for the occurrence of AEs, with a composite CUSUM at 47 procedures.

CONCLUSION

CR-ESD even in non-endemic area is associated with high en bloc resection rates, R0 resection rates and acceptable complication profile. Approximately 50 cases of CR-ESD are required to achieve competency.

Development and evaluation of a program based on a generative pre-trained transformer model from a public natural language processing platform for efficiency enhancement in post-procedural quality control of esophageal endoscopic submucosal dissection

BACKGROUND

Post-procedural quality control of endoscopic submucosal dissection (ESD) is emphasized in guidelines. However, this process can be tedious and time-consuming. Recently, a pre-training model called generative pre-trained transformer (GPT) on a public natural language processing platform has emerged and garnered significant attention, whose capabilities align well with the post-procedural quality control process and have the potential to streamline it. Therefore, we developed a simple program utilizing this platform and evaluated its performance.

METHODS

Esophageal ESDs were retrospectively included. The manual quality control process was performed and act as reference standard. GPT's prompt was optimized through multiple iterations. A Python program was developed to automatically submit prompt with pathological report of each ESD procedure and collect quality control information provided by GPT. Its performance on quality control was evaluated with accuracy, precision, recall, and F-1 score.

RESULTS

165 cases were involved into the dataset, of which 5 were utilized as the prompt optimization dataset and 160 as the validation dataset. Definitive prompt was achieved through seven iterations. Time spent on the validation dataset by GPT was 13.47 ± 2.43 min. Accuracies of pathological diagnosis, invasion depth, horizontal margin, vertical margin, vascular invasion, and lymphatic invasion of the quality control program were (0.940, 0.952) (95% CI), (0.925, 0.945) (95% CI), 0.931, 1.0, and 1.0, respectively. Precisions were (0.965, 0.969) (95% CI), (0.934, 0.954) (95% CI), and 0.957 for pathological diagnosis, invasion depth, and horizontal margin, respectively. Recalls were (0.940, 0.952) (95% CI), (0.925, 0.945) (95% CI), and 0.931 for factors as mentioned, respectively. F1-score were (0.945, 0.957) (95% CI), (0.928, 0.948) (95% CI), and 0.941 for factors as mentioned, respectively.

CONCLUSIONS

This quality control program was qualified of post-procedural quality control of esophageal ESDs. GPT can be easily applied to this quality control process and reduce workload of the endoscopists.

Untutored training pathway to achieve competence in esophagogastric endoscopic submucosal dissection in a Western center

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) has a long learning curve. The aim of this study was to assess the efficacy of an ESD unsupervised training model for experienced endoscopists.

METHODS

Stepwise training included a visit to a high-volume center, unsupervised training on an ex vivo porcine model, and in vivo human upper GI cases with anatomic progression. Performance measures included en bloc resection, R0 resection, adverse event rates, and operating time.

RESULTS

After observation of 30 esophagogastric ESDs and 15 untutored ex vivo ESDs, 5 human cases of distal gastric ESDs were performed, followed by 55 unselected esophagogastric cases. En bloc and R0 resection rates were 93.0% and 80.7%, respectively. Operating time was 14.0 min/cm2 in the stomach and 25.1 min/cm2 in the esophagus, with evidence of a learning curve for esophageal ESDs (first block 30.26 min/cm2 vs second block 14.81 min/cm2, P = .01).

CONCLUSIONS

Untutored training for esophagogastric ESD is feasible and allows endoscopists, experienced in therapeutic endoscopy, to achieve the required standards toward competency.

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.

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.

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.

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

BACKGROUND

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

SUMMARY

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

KEY MESSAGE

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

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.

Comparison among different techniques for en-bloc resection of rectal lesions: transanal endoscopic surgery vs. endoscopic submucosal dissection vs. full-thickness resection device with Over-The-Scope Clip® System

BACKGROUND

The aim of our retrospective study is to compare the efficacy and indications of transanal endoscopic microsurgery (TEM), endoscopic submucosal dissection (ESD), and endoscopic full-thickness resection device (FTRD) with Over-The-Scope Clip (OTSC®) System for en-bloc resection of rectal lesions.

METHODS

This study collected 76 cases of rectal neoplasms from a single hospital institution. Primary endpoints were complete en-bloc resection, intraprocedural adverse events, R0 en-bloc resection and an early discharge of the patient. Secondary endpoints included procedure-related adverse events.

RESULTS

Mean tumor sizes were statistically significant smaller among patients treated with FTRD rather than TEM and ESD. TEO and FTRD treated patients experienced a higher en-bloc resection rate, with a shorter procedure time and hospital stay. No significant difference concerning the R0 resection was found. TEO and FTRD recorded lower perforation rates as compared to ESD, whereas no difference emerged concerning the bleeding rate and the post-polypectomy syndrome rate.

CONCLUSIONS

Our study showed that each technique has specific features, so that each one offers advantages and disadvantages. Nevertheless, all of them ensure high en-bloc resection rates, whereas no difference exists for R0 resection rate. TEO provides the possibility to remove low rectal large lesions as compared to ESD and FTRD.

Feasibility and learning curve of unsupervised colorectal endoscopic submucosal hydrodissection at a Western Center

OBJECTIVES

Colorectal endoscopic submucosal dissection (CR-ESD) is an evolving technique in Western countries. We aimed to determine the results of the untutored implementation of endoscopic submucosal hydrodissection for the treatment of complex colorectal polyps and establish the learning curve for this technique.

METHODS

This study included data from 80 consecutive CR-ESDs performed by a single unsupervised western therapeutic endoscopist. To assess the learning curve, procedures were divided into four groups of 20 each.

RESULTS

En bloc resection was achieved in 55, 75, 75 and 95% cases in the consecutive time periods (period 1 vs. 4, P = 0.003). Curative resection was achieved in 55, 75, 70 and 95%, respectively (P = 0.037). Overall, series results demonstrated R0 resection in 75% of cases, with 23.7% requiring conversion to endoscopic piecemeal mucosal resection, and 1.25% incomplete resections. Complications included perforations (7.5%) and bleeding (3.7%). Multivariate analysis revealed factors more likely to result in association with non en bloc vs. En bloc resection, where polyp size ≥35 mm [70 vs. 23.4%; odds ratio (OR) 13.2 (1.7-100.9); P = 0. 013], severe fibrosis [40 vs. 11.7%; OR 10.2 (1.2-86.3); P = 0.033] and where carbon dioxide for insufflation was not used [65 vs. 30%; OR 0.09 (0.01-0.53); P = 0.008].

CONCLUSION

CR-ESD by hydrodissection has good safety and efficacy profile and offers well tolerated and effective treatment for complex polyps. As such, this technique may be useful in the West, in centers, where previous gastric ESD is not frequent or Japanese mentoring is not possible.

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

BACKGROUND & AIMS

Endoscopic submucosal dissection (ESD) is widely used in Asia to resect early-stage gastrointestinal neoplasms, but use of ESD in Western countries is limited. We collected data on the learning curve for ESD at a high-volume referral center in the United States to guide development of training programs in the Americas and Europe.

METHODS

We performed a retrospective analysis of consecutive ESDs performed by a single operator at a high-volume referral center in the United States from 2009 through 2017. ESD was performed in 540 lesions: 449 mucosal (10% esophageal, 13% gastric, 5% duodenal, 62% colonic, and 10% rectal) and 91 submucosal. We estimated case volumes required to achieve accepted proficiency benchmarks (>90% for en bloc resection and >80% for histologic margin-negative (R0) resection) and resection speeds >9cm²/hr.

RESULTS

Pathology analysis of mucosal lesions identified 95 carcinomas, 346 premalignant lesions, and 8 others; the rate of en bloc resection increased from 76% in block 1 (50 cases) to a plateau of 98% after block 5 (250 cases). The rate of R0 resection improved from 45% in block 1 to >80% after block 5 (250 cases) and ∼95% after block 8 (400 cases). Based on cumulative sum analysis, approximately 170, 150, and 280 ESDs are required to consistently achieve a resection speed >9cm²/hr in esophagus, stomach, and colon, respectively.

CONCLUSIONS

In an analysis of ESDs performed at a large referral center in the United States, we found that an untutored, prevalence-based approach allowed operators to achieve all proficiency benchmarks after ∼250 cases. Compared with Asia, ESD requires more time to learn in the West, where the untutored, prevalence-based approach requires resection of challenging lesions, such as colon lesions and previously manipulated lesions, in early stages of training.

Endoscopic full-thickness resection using an over-the-scope device for treatment of recurrent / residual colorectal neoplasia: a single-center case series

Background

Endoscopic mucosal resection (EMR) in piecemeal technique is the treatment standard for larger flat or sessile colorectal lesions. The method is burdened by a high recurrence rate mostly presenting as difficult to resect lesions. In these situations, endoscopic full thickness resection (EFTR) with an over-the-scope device offers the option of complete resection despite scar formation.

Methods

We conducted a retrospective case review of 30 consecutive EFTR interventions on small (< 20 mm), difficult to resect recurrent / residual colorectal neoplastic lesions treated by EFTR.

Results

EFTR was technically feasible in 28/30 (93,3%) of the cases with an R0 resection in 24/30 (80%) and a median procedure time (marking to full thickness resection) of 34,5 min (11–120). After the first 15 procedures, the per-protocol rate increased from 13/15 to 15/15 and the R0 resection rate increased from 9/15 (69,2%) to 15/15 (100,0%; p < 0.01). One patient suffered from a delayed perforation the day after the procedure and needed emergency surgery (3,6%). Minor bleeding occurred in 3/28 patients (10,7%) and post-interventional fever in one patient (3,6%). The 30-day mortality rate was 0%.

Conclusions

EFTR with an over-the-scope device is a useful method for endoscopic resection of difficult to treat recurrent or residual colorectal neoplasia after previous endoscopic therapy. High R0 resection rates were observed after a relatively short learning curve. The complication rate in this series seems acceptable given the complexity of the resected lesions.

Implementation of endoscopic submucosal dissection for early upper gastrointestinal tract cancer after primary experience in colorectal endoscopic submucosal dissection

Background  Current guidelines recommend endoscopic submucosal dissection (ESD) as a treatment option for early cancers of the upper gastrointestinal tract with absent or minimal risk of lymph node metastasis. However, due to the low prevalence of these entities, it is difficult to achieve a competence level for ESD of upper gastrointestinal tract cancers in the Western World. Here, we present single-center data on the implementation of upper gastrointestinal ESD after previous experience with 89 colorectal ESD cases. Methods  Retrospective case series of 39 consecutive patients with early cancers of the esophagus (n = 13) or cardia and stomach (n = 26) treated with ESD over a 4-year period. Results  ESD was technically feasible in all cases with en bloc, R0, and curative resection rates of 100 %, 76.9 %, and 71.8 %, respectively, and a mean procedure time of 100 minutes (30 - 360 minutes). After an initial 20 procedures, the R0 and curative resection rates increased from 65.0 % to 89.5 %, and from 60.0 % to 84.2 %, respectively. Complications were observed in four patients (10.3 %): three perforations, one case of delayed bleeding, and one esophageal stricture. No case required emergency surgery; the 30-day mortality rate was 0 %. Conclusion  In this modest case series from Europe, we observed an effectiveness and complication rate for ESD for early esophageal and gastric cancer that are comparable to other series from Europe but also to more abundant data from Asia. The results indicate that even small numbers of upper gastrointestinal cancers can be managed adequately in centers with expertise in colorectal ESD.

Management of colorectal laterally spreading tumors: a systematic review and meta-analysis

Objective and study aims  To evaluate the efficacy and safety of different endoscopic resection techniques for laterally spreading colorectal tumors (LST). Methods  Relevant studies were identified in three electronic databases (PubMed, ISI and Cochrane Central Register). We considered all clinical studies in which colorectal LST were treated with endoscopic resection (endoscopic mucosal resection [EMR] and/or endoscopic submucosal dissection [ESD]) and/or transanal minimally invasive surgery (TEMS). Rates of en-bloc/piecemeal resection, complete endoscopic resection, R0 resection, curative resection, adverse events (AEs) or recurrence, were extracted. Study quality was assessed with the Newcastle-Ottawa Scale and a meta-analysis was performed using a random-effects model. Results  Forty-nine studies were included. Complete resection was similar between techniques (EMR 99.5 % [95 % CI 98.6 %-100 %] vs. ESD 97.9 % [95 % CI 96.1 - 99.2 %]), being curative in 1685/1895 (13 studies, pooled curative resection 90 %, 95 % CI 86.6 - 92.9 %, I ²  = 79 %) with non-significantly higher curative resection rates with ESD (93.6 %, 95 % CI 91.3 - 95.5 %, vs. 84 % 95 % CI 78.1 - 89.3 % with EMR). ESD was also associated with a significantly higher perforation risk (pooled incidence 5.9 %, 95 % CI 4.3 - 7.9 %, vs. EMR 1.2 %, 95 % CI 0.5 - 2.3 %) while bleeding was significantly more frequent with EMR (9.6 %, 95 % CI 6.5 - 13.2 %; vs. ESD 2.8 %, 95 % CI 1.9 - 4.0 %). Procedure-related mortality was 0.1 %. Recurrence occurred in 5.5 %, more often with EMR (12.6 %, 95 % CI 9.1 - 16.6 % vs. ESD 1.1 %, 95 % CI 0.3 - 2.5 %), with most amenable to successful endoscopic treatment (87.7 %, 95 % CI 81.1 - 93.1 %). Surgery was limited to 2.7 % of the lesions, 0.5 % due to AEs. No data of TEMS were available for LST. Conclusions  EMR and ESD are both effective and safe and are associated with a very low risk of procedure related mortality.

Endoscopic resection techniques for colorectal neoplasia: Current developments

Endoscopic polypectomy and endoscopic mucosal resection (EMR) are the established treatment standards for colorectal polyps. Current research aims at the reduction of both complication and recurrence rates as well as on shortening procedure times. Cold snare resection is the emerging standard for the treatment of smaller (< 5mm) polyps and is possibly also suitable for the removal of non-cancerous polyps up to 9 mm. The method avoids thermal damage, has reduced procedure times and probably also a lower risk for delayed bleeding. On the other end of the treatment spectrum, endoscopic submucosal dissection (ESD) offers en bloc resection of larger flat or sessile lesions. The technique has obvious advantages in the treatment of high-grade dysplasia and early cancer. Due to its minimal recurrence rate, it may also be an alternative to fractionated EMR of larger flat or sessile lesions. However, ESD is technically demanding and burdened by longer procedure times and higher costs. It should therefore be restricted to lesions suspicious for high-grade dysplasia or early invasive cancer. The latest addition to endoscopic resection techniques is endoscopic full-thickness resection with specifically developed devices for flexible endoscopy. This method is very useful for the treatment of smaller difficult-to-resect lesions, e.g., recurrence with scar formation after previous endoscopic resections.

USEFULNESS OF GASTRIC SUBMUCOSAL DISSECTION DEPTH TO EVALUATE SKILL ACQUIREMENT IN SHORT TERM TRAINING COURSES IN ESD: AN EXPERIMENTAL STUDY

BACKGROUND

Endoscopic submucosal dissection (ESD) is a complex endoscopic procedure, with high rates of adverse events and technical difficulties. To overcome that problem, many training centers published the importance of animal models for skill acquirement in ESD. However, no study has used the submucosal dissection depth (DSUB) as a parameter to evaluate the learning curve in ESD, which might be a relevant factor since an optimal resection plane is important to achieve a curative resection and avoid intraoperative complications.

OBJECTIVE

This study aimed to assess ESD skill acquirement after short-term training sessions by evaluating the submucosal dissection depth (DSUB) and the association with adverse events.

METHODS

This experimental study included 25 experienced endoscopists in therapeuthic procedures (>5years) and 75 specimens resected by ESD (three resections / endoscopist). Learning parameters (resection time, size, en bloc resection rate, bleeding, perforation and submucosal dissection depth) were prospectively evaluated. The percentages of DSUB of all specimens resected were calculated.

RESULTS

All specimens were resected from the gastric body (n=75). The mean size of the resected specimens was 23.97±7.2 mm. The number of adverse events, including bleeding, perforation, and death, were 17 (22.67%), 3 (4%), and 0 cases, respectively. The average mean time by the third dissection decreased from 28.44±9.73 to 18.72±8.81 min (P<0.001). The proportion of DSUB in the bleeding and non-bleeding group were respectively 37.97%±21.13% and 68.66%±23.99%, indicating a significant association between DSUB and bleeding incidence (P<0.001). The ROC curve analysis indicated a cut-off point of 61% (sensitivity, 64%; specificity, 94%) of submucosal dissection depth associated with bleeding. Therefore, when ESD was performed at a depth of >61% of the submucosal layer, the risk for bleeding during the procedure decreased (PPV, 0.97; 95% CI, 0.85-0.99).

CONCLUSION

Improvement in the learning curve in ESD and a better cognitive ability were seen by the third dissection in these short term training courses. And a significant association between DSUB and the risk of bleeding.

Introduction of endoscopic submucosal dissection in the West

Endoscopic submucosal dissection (ESD) is well established in Asia as a modality for selected advanced lesions of both the upper and lower gastrointestinal tract, but ESD has not attained the same niche in the West due to a variety of reasons. These include competition from traditional surgery, minimally invasive surgery and endoscopic mucosal resection. Other obstacles to ESD introduction in the West include time commitment for learning and doing procedures, a steep learning curve, special equipment, lack of mentors, cost issues, interdisciplinary conflicts, concern regarding complications and lack of support from institutions and interfacing departments. There are intrinsic differences in pathology prevalence (e.g., early gastric cancer) between the two regions that are less conducive for ESD implementation in the West. We will elaborate on these issues and suggest measures as well as a protocol to overcome these obstacles and hopefully allow introduction of ESD as a tenable option for appropriate patients.

Endoscopic submucosal dissection (ESD) for anal high-grade intraepithelial neoplasia: a case report

Anal intraepithelial neoplasia (AIN) is a precursor of anal carcinoma. Conventional therapy is based on topical and local ablative approaches. However, the recurrence rates are very high, leading to repetitive treatment sessions and need for long-term surveillance. Endoscopic submucosal dissection (ESD) is an established treatment for malignant early neoplasias of the gastrointestinal tract, especially in the esophagus, stomach, and colorectum. Japanese centers have reported few cases of ESD for early anal carcinoma. We report a case of high-grade AIN diagnosed with magnifying narrow-band imaging and chromoendoscopy that was resected R0 with ESD en bloc.

Single-center implementation of endoscopic submucosal dissection (ESD) in the colorectum: Low recurrence rate after intention-to-treat ESD

BACKGROUND AND AIM

Colorectal endoscopic submucosal dissection (ESD) shows higher R0 resection and lower local recurrence rates than endoscopic mucosal resection (EMR) in Japan. In Europe, independent learning of ESD in the colorectum is feasible, but yet to be analyzed for curative resection and recurrence rates.

METHODS

After experimental training under supervision by Japanese experts (T.O., N.Y.), three endoscopists independently carried out 83 ESD procedures intention-to-treat for lesions in the entire colorectum of 67 patients in a prospective registry (November 2009 to June 2016).

RESULTS

ESD was feasible in 80 (96%) colorectal neoplasias (mean diameter 33.6 [± 1.8] mm), and three more required conversion to piecemeal EMR. The lesions were adenomas in 66% with low-grade intraepithelial neoplasia (LGIN), 29% with high-grade intraepithelial neoplasia, and 5% with carcinomas (G2, pT1). ESD had to be facilitated by the final use of snaring (hybrid-ESD, n = 45), especially in the initial learning period. En-bloc resection rate was 85%. Complications were microperforations (7%, conducive to one hemicolectomy), and delayed bleeding (1%) without mortality or long-term morbidity. Residual adenomas with LGIN (5%) after hybrid-ESD did not recur after endoscopic ablation. All malignant neoplasias (34%) were curatively resected without recurrence after a mean follow up of 19.5 (± 3.2) months.

CONCLUSIONS

During independent ESD learning in the colorectum, ESD intention-to-treat showed a low recurrence rate after appropriate training, and hybrid-ESD showed acceptable complication and recurrence rates, justifying hybrid-ESD as a strategy for self-completion and rescue.

A local structured training program with live pigs allows performing ESD along the gastrointestinal tract with results close to those of Japanese experts

BACKGROUND AND AIMS

The high specific skill needed by ESD limit its widespread use in Europe and animal training is recommended in Europe to improve the results of ESD that are far from Japanese at present. We create a local training program using live pigs as models, along with our human cases, to provide continuous exposure to the technique.

METHODS

Between February 2013 and December 2015, two young operators performed 55 pig gastric ESDs in parallel with 62 human cases for large superficial cancerous lesions. The number and training dates of pig cases were adapted to those of the human cases to achieve continuous exposure to ESD cases.

RESULTS

The en bloc, R0, and curative resection rates were 100%, 85.5% (53/62), and 77.5% (48/62), respectively with no recurrence observed during the one year follow up. There was no statistically significant difference in terms of the R0 or curative resection rates among ESDs performed during 2013-2015 (R0: 80% vs. 86.6% vs. 86.4%; Curative: 80% vs. 86.6% vs. 73%).

CONCLUSION

A local structured training program using live pig models was used to train endoscopists for ESD in humans with high safety and efficiency, similar to results published by Japanese experts.

Histomorphologic features of early gastric carcinoma treated by endoscopic submucosal dissection: relation to efficiency of endoscopic resection

OBJECTIVE

Early gastric cancer (EGC) is defined as cancer invasion confined to the mucosa or submucosa, irrespective of lymph node metastasis. Recently endoscopic submucosal dissection (ESD) has been widely accepted for the treatment for dysplasia and EGC without lymph node metastases. While the method has been advanced in Far East countries, ESD is still being developed in Europe and has not gained enough popularity although it has been recommended as the treatment of choice for superficial gastric neoplastic lesions by European Society of Gastrointestinal Endoscopy (ESGE) in 2015.

METHODS

The aim of the study was to perform a retrospective analysis of clinical and histomorphologic features of 58 cases of EGCs removed by ESD in a university hospital in Western Pomerania in Poland and to evaluate factors related to the efficiency of ESD resection.

RESULTS

With univariate analysis, indications for ESD with the highest R0 rate were found in EGCs limited to mucosa (T1a, small mucosal, M), without muscularis mucosa invasion, localised in the middle/lower part of stomach and intestinal type in histological examination. The R0 complete resection rate was significantly (p < 0.0001) lower for T1b than that for T1a tumours (21.4% vs. 100%). Tumours with submucosal involvement were associated with lower efficiency of ESD procedure.

CONCLUSIONS

Our data showed that in EGCs with favourable histomorphologic characteristics, ESD seemed to be a totally efficient and safe method of treatment in a European small-volume centre. R0 resection rate reached 81.1% of cases and median time of the ESD procedure was 61.5 min.

Endoscopic submucosal dissection for flat or sessile colorectal neoplasia > 20 mm: A European single-center series of 182 cases

BACKGROUND AND STUDY AIMS

Colorectal endoscopic submucosal dissection (ESD) is an attractive method for en bloc resection of larger flat neoplastic lesions. Experience with this method is limited in the Western World.

PATIENTS AND METHODS

A total of 182 consecutive flat or sessile colorectal lesions (cecum n = 43; right-sided colon n = 65; left-sided colon n = 11, rectum: n = 63) with a size > 20 mm (mean 41.0 ± 17.4 mm) were resected in 178 patients. The data were recorded prospectively.

RESULTS

ESD was technically feasible in 85.2 % of patients with a mean procedure time of 127.5 min (± 99.8) min and a complication rate of 11.5 % (microperforation 9.3 %, delayed bleeding 2.7 %, no case of emergency surgery, 30-day mortality rate 0 %). For 155 successfully completed procedures the en bloc and R0 resection rates were 88.4 and 62.6 %. Efficacy was better for smaller lesions (20 mm to 49 mm; n = 131) than for larger lesions (50 mm to 140 mm; n = 51) with R0 rates of 70.8 vs. 40.5 % (P < 0.001) and procedure times of 92.7 ± 62.4 minutes vs. 217.0 ± 120.9 minutes (P < 0,001).

CONCLUSIONS

This series confirms the efficacy of ESD for en bloc resection of colorectal lesions > 20 mm. RESULTS are satisfactory for lesions up to 50 mm. ESD for larger lesions was associated with low R0 resection rates and very long procedure times. The clinical consequences of microperforations were minor and do not argue against the spread of ESD in the West. Meeting presentations: The data were presented in part at DDW 2014, Chicago IL, USA (Gastrointest Endosc 2014; 79: AB536).

Colorectal endoscopic submucosal dissection from a Western perspective: Today’s promises and future challenges

Over the last few years, endoscopic submucosal dissection (ESD) has shown to be effective in the management of early colorectal neoplasms, particularly in Asian countries where the technique was born. In the Western world, its implementation has been slow and laborious. In this paper, the indications for ESD, its learning model, the available methods to predict the presence of deep submucosal invasion before the procedure and the published outcomes from Asia and Europe will be reviewed. Since ESD has several limitations in terms of learning achievement in the West, and completion of the procedure for the first cases is difficult in our part of the world, a short review on colorectal assisted ESD has been included. Finally, other endoscopic and surgical treatment modalities that are in competition with colorectal ESD will be summarized.

How to establish endoscopic submucosal dissection in Western countries

Endoscopic submucosal dissection (ESD) has been invented in Japan to provide resection for cure of early cancer in the gastrointestinal tract. Professional level of ESD requires excellent staging of early neoplasias with image enhanced endoscopy (IEE) to make correct indications for ESD, and high skills in endoscopic electrosurgical dissection. In Japan, endodiagnostic and endosurgical excellence spread through personal tutoring of skilled endoscopists by the inventors and experts in IEE and ESD. To translocate this expertise to other continents must overcome two fundamental obstacles: (1) inadequate expectations as to the complexity of IEE and ESD; and (2) lack of suitable lesions and master-mentors for ESD trainees. Leading endoscopic mucosal resection-proficient endoscopists must pioneer themselves through the long learning curve to proficient ESD experts. Major referral centers for ESD must arise in Western countries on comparable professional level as in Japan. In the second stage, the upcoming Western experts must commit themselves to teach skilled endoscopists from other referral centers, in order to spread ESD in Western countries. Respect for patients with early gastrointestinal cancer asks for best efforts to learn endoscopic categorization of early neoplasias and skills for ESD based on sustained cooperation with the masters in Japan. The strategy is discussed here.

Ex vivo comparison study of smart Shooter®, a new endoscopic device for safe and speedy treatment

BACKGROUND

In many endoscopic procedures, the operative view can be compromised when manipulating the treatment device because the endoscopists must release their hand from the endoscope. We have developed a new device called the Smart Shooter® (SS) for simultaneous manipulation of the endoscope and treatment device, and evaluated the utility of the SS compared with the conventional method.

METHODS

The SS is a semirigid, loop-shaped channel extender that enables endoscopists to manipulate the treatment device with the thumb of the right hand while holding the endoscope with the same hand. We conducted a comparative study of gastric endoscopic submucosal dissection (ESD) and esophageal injection sclerotherapy (EIS) in a porcine model to compare the utility of the SS method with the conventional method.

RESULTS

In gastric ESD, all lesions were resected en bloc with no perforation. The mean operative time was significantly shorter with the SS method than with the conventional method (287.5 ± 155.4 vs. 403.5 ± 215.6 s, p = 0.04). In esophageal EIS, 4 paravenous injections were given with the SS method and 5 were given using the conventional method. Similarly, the mean operative time was significantly shorter with the SS method than with the conventional method (19.0 ± 7.8 vs. 23.8 ± 10.0 s, p = 0.04).

CONCLUSION

Use of the SS enabled a shorter operative time for gastric ESD and esophageal EIS with no adverse events. The present results suggest that the SS can contribute to safe and speedy endoscopic treatment.

Impact of formal training in endoscopic submucosal dissection for early gastrointestinal cancer: A systematic review and a meta-analysis

AIM: To summarize the clinical impact of a formal training for the effectiveness and safety of endoscopic submucosal dissection for gastrointestinal cancer.

METHODS: We searched databases including PubMed, EMBASE and the Cochrane Library and Science citation Index updated to August 2014 to include eligible articles. In the Meta-analysis, the main outcome measurements were en bloc resection rate, local recurrence rate (R0) and the incidence of procedure-related complications (perforation, bleeding).

RESULTS: En bloc resection was high for both, dissecting stomach tumors with an overall percentage of 93.2% (95%CI: 90.5-95.8) and dissecting colorectal tumors with an overall percentage of 89.4% (95%CI: 85.1-93.7). Although the number of studies reporting R0 resection (the dissected specimen was revealed free of tumor in both vertical and lateral margins) was small, the overall estimates for R0 resection were 81.4% (95%CI: 72-90.8) for stomach and 85.9% (95%CI: 77.5-95.5) for colorectal tumors, respectively. The analysis showed that the percentage of immediate perforation and bleeding were very low; 4.96 (95%CI: 3.6-6.3) and 1.4% (95%CI: 0.8-1.9) for colorectal tumors and 3.1% (95%CI: 2.0-4.1) and 4.8% (95%CI: 2.8-6.7) for stomach tumors, respectively.

CONCLUSION: In order to obtain the same rate of success of the analyzed studies it is a necessity to create training centers in the western countries during the “several years” of gastroenterology residence first only to teach EGC diagnose and second only to train endoscopic submucosal dissection.

New isolated bovine colon model dedicated to colonic ESD hands-on training: development and first evaluation

INTRODUCTION

ESD is the reference method to achieve en bloc resections for large digestive lesions. Nevertheless, it is a difficult and risky technique. Animal models exist to teach the initial skills, particularly in Japan, where pigs' stomachs are dedicated models to gastric ESD. In Europe, we have to develop different strategies of teaching with dedicated colon models. A pig colon is a good model but thinner and narrower than a human's. In this present work, we evaluated a bovine colon model to perform rectal ESD in retroflexion.

METHODS

First, we prepared six bowels to precise the preparation protocol. Then, two endoscopists unexperienced in ESD performed 64 procedures on eight models. Learning curves and factors of variation were studied.

RESULTS

A precise protocol to prepare the colon was defined. The two students achieved en bloc resection in 89.1 % of cases with a rate of 6.2 % of perforations. A large heterogeneity appeared between the speed and the success rate depending mainly on the age of the animal bowel. Using calf colons, the failure rates were higher (p = 0.002) and the speed was lower (p < 0.001) than for adult bovine ones. A learning curve appeared with, respectively, 0.49 and 0.59 cm(2)/min throughout the study. No significant difference appeared between measured and calculated specimen areas.

DISCUSSION

Bovine colon is a new model to teach ESD in colorectal conditions. The bovine age is important to homogenize the model. A learning curve existed with a time procedure decreasing throughout the study. Further studies are needed to evaluate the precise learning curve with more students.

CONCLUSION

A bovine colon model is a suitable model to teach colorectal ESD. Nevertheless, an adult bovine colon model is more homogeneous than a calf one.