Stepwise training in rectal and colonic endoscopic submucosal dissection with differentiated learning curves

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.

Predictive Factors for the Outcome of Unsupervised Endoscopic Submucosal Dissection During the Initial Learning Curve with Prevalence-Based Indication

BACKGROUND

For an adequate educational strategy of ESD in non-Asian settings with prevalence-based indication it is essential to define adequate lesions, suitable for the beginner without on-site expert-supervision.

AIMS

We analyzed possible predictors for outcome parameters of effectiveness and safety during the initial learning curve.

METHODS

The first 120 ESDs of four operators (n = 480), performed between 2007 and 2020 in four tertiary hospitals, were enrolled. Uni-/multivariable regression analysis was done with sex, age, pretreated lesion, lesion size, organ, and organ-based localization as possible independent predictors for en bloc resection (EBR), complication, and resection speed.

RESULTS

Rates of EBR, complication, and resection speed were 84.5%, 14.2%, and 6.20 (± 4.45) cm2/h. Independent predictors for EBR were pretreated lesion (OR 0.27 [0.13-0.57], p < 0.001) and non-colonic ESD (OR 2.29 [1.26-4.17] (rectum)/5.72 [2.36-13.89] (stomach)/7.80 [2.60-23.42] (esophagus), p < 0.001), for complication pretreated lesion (OR 3.04 [1.46-6.34], p < 0.001) and lesion size (OR 1.02 [1.004-1.04], p = 0.012) and for resection speed pretreated lesion (RC - 3.10 [- 4.39 to - 1.81], p < 0.001), lesion size (RC 0.13 [0.11-0.16], p < 0.001) and male patient (RC - 1.11 [- 1.85 to - 0.37], p < 0.001). We found no significant difference in the incidence of technically unsuccessful resections in esophageal (1/84), gastric (3/113), rectal (7/181), and colonic (3/101) ESDs (p = 0.76). Technical failure was mainly caused by complication and fibrosis/pretreatment.

CONCLUSION

During the initial learning curve of an unsupervised ESD program with prevalence-based indication, pretreated lesions and colonic ESDs should be avoided. In contrast, lesion size and organ-based localizations have less predictive value for the outcome.

Factors associated with increased duration of endoscopic submucosal dissection for rectal tumors: a 22-year retrospective analysis

BACKGROUND AND AIMS

Colorectal endoscopic submucosal dissection (ESD) is widely used in several countries. However, it is associated with technical difficulties. Rectal ESD is considered an intermediate step in colorectal ESD training. Nevertheless, some rectal lesions require a longer procedure time than usual, and the reason for the prolonged time taken for these specific lesions remains unclear. Therefore, this study aimed to clarify the factors associated with prolonged rectal ESD.

METHODS

In total, 483 rectal lesions resected using ESD from February 1998 to June 2021 were investigated. Prolonged ESD procedure time was defined as the time from the first submucosal injection to lesion removal exceeding 120 minutes, whereas other procedures were defined as average ESD procedure time. Clinicopathologic and endoscopic findings were compared between the 2 groups using univariate and multivariate analyses.

RESULTS

One hundred forty-four lesions were resected using a prolonged ESD procedure time of 202.9 ± 92.3 minutes, whereas 339 lesions were resected using an average ESD procedure time of 77.8 ± 29.4 minutes. Multivariate analysis revealed that tumors involving the dentate line (P = .026), resection size ≥50 mm (P < .001), invasion depth ≥T1b (P = .006), and circumferential range ≥2/3 (P = .001) were independent risk factors for prolonged-duration ESDs, regardless of whether the procedure was performed by an expert or not.

CONCLUSIONS

The results of the present study suggest that the location of a lesion involving the dentate line, resection size ≥50 mm, circumferential range ≥2/3, and invasion depth ≥T1b are the independent risk factors for prolonged ESD procedure time.

Safe and Efficient Procedures and Training System for Endoscopic Submucosal Dissection

Recent improvements in endoscopists' skills and technological advances have allowed endoscopic submucosal dissection (ESD) to become a standard treatment in general hospitals. As this treatment entails a high risk of accidental perforation or hemorrhage, therapeutic procedures and training methods that enable ESD to be conducted more safely and efficiently are constantly being developed. This article reviews the therapeutic procedures and training methods used to improve the safety and efficiency of ESD and describes the ESD training system used in a Japanese university hospital at which the number of ESD procedures has gradually increased in a newly established Department of Digestive Endoscopy. During the establishment of this department, the ESD perforation rate was zero among all procedures, including those conducted by trainees.

Training in esophageal peroral endoscopic myotomy (POEM) on an ex vivo porcine model: learning curve study and training strategy

BACKGROUND

Peroral endoscopic myotomy (POEM) is a very effective treatment for achalasia. However, training remains non-standardized. We evaluated a training curriculum, including ex vivo cases, followed by patients' cases under expert supervision. The objective was to establish a learning curve of POEM.

MATERIALS AND METHODS

Four operators having completed advanced endoscopy fellowship were involved. They had already observed > 30 cases performed by experts. They performed 30 POEMs standardized (tunnel and myotomy lengths) procedures on ex vivo porcine model. Procedural times, number/volume of injections, mucosal and serous perforations, and myotomy length were collected. The learning curve was assessed using dissection speed (DS) and a dedicated performance score (PS), including learning rate (LR) and learning plateau (LP).

RESULTS

The operators completed all cases within 4 months (median of 3.5 cases/week). The mean procedural time was 43.3 min ± 14.4. Mean myotomy length was 70.0 mm ± 15.6 mm. Dissection speed averaged 1.78 mm/min ± 0.78. Using DS and PS as parameter, the LR was reached after 12.2 cases (DS = 2.0 mm/min) and 10.4 cases, respectively. When comparing the LP and the plateau phase, the DS was slower (1.3 ± 0.5 mm/min versus 2.1 ± 0.54 mm/min, p < 0.005) and perforations were decreased: 0.35 ± 0.82 in LP vs. 0.16 ± 0.44 in PP. Following this training, all operators performed 10 supervised cases and are competent in POEM.

CONCLUSION

The association of observed cases and supervised ex vivo model training is effective for starting POEM on patients. The learning curve is 12 cases to reach a plateau.

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.

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.

Simulation training of laparoscopic pancreaticojejunostomy and stepwise training program on a 3D-printed model

AIM

Laparoscopic pancreaticojejunostomy is among the most difficult and high-risk operations. Surgeons with low or moderate seniority rarely are allowed to perform this surgery in clinics. Therefore, there is an urgent need to develop a reliable simulation training model focused on laparoscopic pancreaticojejunostomy and an effective stepwise training program.

METHODS

Surgeons with different working experiences or exposure to different training programs at Sir Run Run Shaw Hospital were divided into four groups. Each was required to perform laparoscopic pancreaticojejunostomy using a designed three-dimensional dry lab model. All surgeons' baseline characteristics and surgical performance, including operation time and score, were recorded and analysed. The authenticity of the model was evaluated by four senior surgeons.

RESULTS

The surgeon group with higher seniority had an older average age, longer working time, and had completed more laparoscopic cholecystectomy and laparoscopic common bile duct exploration procedures. Meanwhile, the surgeon group with higher seniority presented better operation performance, including shorter operation time and higher operation score in their initial simulation training. Resident surgeons who underwent stepwise training with the laparoscopic biliary-enteric anastomosis training program showed better initial performance than resident surgeons who underwent stepwise training with the laparoscopic basic suture training program. After repeated training, the surgeons showed improved surgical performance.

CONCLUSION

Our pancreaticojejunostomy model showed a good degree of discernibility, as surgeons with more experience performed better with the model for their initial simulation training in laparoscopic pancreaticojejunostomy. Stepwise training of the laparoscopic biliary-enteric anastomosis training program helped surgeons obtain a better initial performance, and repeated simulation training on this model improved the surgeon's operative performance.

Ex vivo porcine model study on the treatment outcomes of scissor-type knife versus needle-type knife in endoscopic submucosal dissection performed by trainees

Background

Endoscopic submucosal dissection (ESD) for gastrointestinal neoplasms can be technically difficult for trainee endoscopists. Presently, there is no consensus for trainees to select the endo-knife type in ESD. Therefore, we conducted a comparison study of treatment outcomes between scissors-type and needle-type knives in ESD performed by trainees in an ex vivo porcine model.

Methods

This study was conducted on trainee endoscopists who participated in ESD hands-on seminars held in August 2018 and September 2019. A total of 22 trainees from 13 institutions were divided into two groups according to their endoscopic experience. Under expert supervision, each trainee performed two ESDs in porcine models, namely, scissor-type knife (ESD-S) and needle-type knife (ESD-N). The efficacy and safety, including the procedure time and rates of self-completion, en bloc resection, and complications, were compared between ESD-S and ESD-N. In subgroup analysis, we also investigated the predictors associated with the difficulty of ESD for trainees using multivariate logistic regression analysis.

Results

Eight trainees had an experience of over 1000 endoscopies (senior trainee: S-Trainee), whereas the others had an experience of less than 1000 endoscopies (junior trainee: J-Trainee). Among the S-Trainees, no significant differences were observed in any treatment outcome between ESD-S and ESD-N. Among the J-Trainees, the total procedure and mucosal incision times were significantly shorter in ESD-S than in ESD-N [total procedure time: 16.5 min (range 10.0–31.0) vs. 22.3 min (range 10.0–38.0), P = 0.018; circumferential incision time: 10.0 min (range 6–16) vs. 17.0 min (range 5.0–31.5); P = 0.019]. Regarding complications, muscular injury occurred in two patients during ESD-N performed by J-Trainees; however, no muscular injury occurred during ESD-S. In subgroup analysis, ESD-N was an independent predictive factor of difficult ESD (odds ratio 5.28, 95% confidence interval 1.25–22.30; P = 0.024).

Conclusions

This study revealed that trainees, particularly those who have experienced less than 1000 endoscopies, should opt for the scissor-type knife to perform ESD.

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.

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.

Review on colorectal endoscopic submucosal dissection focusing on the technical aspect

BACKGROUND

Endoscopic submucosal dissection (ESD) enables removal of broad-based colorectal polyps or lateral spreading tumors with a higher rate of en bloc resection and a lower risk of local recurrence. However, it is technically demanding. Over the past 20 years, various equipment and innovative techniques have been developed to reduce the difficulty of ESD. The information in the literature is scattered. Our aim is to provide a comprehensive review on the setup and technical aspects of colorectal ESD.

METHODS

We searched the PubMed database and systemically reviewed all original and review articles related to colorectal ESD. Further manual search according to reference lists of identified articles were done. The selected articles were categorized and reviewed. Original figures were created to help readers understand some of the ESD techniques.

RESULTS

A total of 216 articles were identified, in which 25 of them were review articles and 191 of them were original articles. They were categorized and reviewed. An in-depth appraisal of the setting, equipment, and technical aspects of colorectal ESD was performed.

CONCLUSIONS

Although ESD is a technically demanding procedure that requires expert endoscopic skills, it can be mastered. With good peri-procedural preparation, sufficient knowledge of the equipment, and thorough understanding of the useful endoscopic tricks and maneuvers, colorectal ESD can be performed smoothly and safely.

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.

Japan Gastroenterological Endoscopy Society guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection

Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also several types of precarcinomatous adenomas. It is important to establish practical guidelines wherein preoperative diagnosis of colorectal neoplasia and selection of endoscopic treatment procedures are appropriately outlined and to ensure that actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society compiled colorectal endoscopic submucosal dissection/endoscopic mucosal resection guidelines by using evidence-based methods in 2014. The first edition of these guidelines was published 5 years ago. Accordingly, we have published the second edition of these guidelines based on recent new knowledge and evidence.

Construction of a preoperative scoring system to predict the difficulty level of colorectal endoscopic submucosal dissection

Background

We attempted to examine the factors contributing to the difficulty in performance of colorectal ESD, with the aim of constructing a scoring system that could help in prediction of the difficulty level of the procedure.

Methods and materials

The data were analyzed from two viewpoints: to determine the factors contributing to 1) non-en bloc resection and the factors contributing to 2) a slow resection speed. Factors falling under these two categories contributing to difficulty in performance of ESD were extracted and used to construct a scoring system. The validity of this scoring system was evaluated by calculating the correlation between the score and the resection speed in a different dataset.

Results

Based on the results of our analysis, we assigned scores for various factors as follows: 4 points for EMR of a scarred lesion, 1 point for tumors with a diameter of ≥ 30 mm, 2 points for lesions located in the liver/splenic flexure, 1 point for lesions located in the transverse colon, 3 points for LST-NG-PD/depressed lesions, 1 point for protruded lesions and LST-NG-F lesions (range 0–10). In the validation study, the rank correlation coefficient between the score according to the scoring system and the resection speed was -0.130, representing a weak and negative correlation (P = 0.03). We defined the difficulty level depending on the sum of the scores: 0–2, low difficulty level; 3–5, intermediate difficulty level; ≥ 6, high difficulty level. The average resection speed was 12.6 mm²/min in the group with scores of 0–2, 8.1 mm²/min in the group with scores of 3–5, and 5.5 mm²/min in the group with scores of ≥ 6 (11.2 mm²/min in all lesions).

Conclusion

Our colorectal ESD scoring system would be useful for selection of operators with the appropriate skill level in the procedure for colorectal ESD cases.

Endoscopic submucosal dissection: a cognitive task analysis framework toward training design

BACKGROUND

One of the major impediments to the proliferation of endoscopic submucosal dissection (ESD) training in Western countries is the lack of sufficient experts as instructors. One way to address this gap is to develop didactic systems, such as surgical simulators, to support the role of trainers. Cognitive task analysis (CTA) has been used in healthcare for the design and improvement of surgical training programs, and therefore can potentially be used for design of similar systems for ESD.

OBJECTIVE

The aim of the study was to apply a CTA-based approach to identify the cognitive aspects of performing ESD, and to generate qualitative insights for training.

MATERIALS AND METHODS

Semi-structured interviews were designed based on the CTA framework to elicit knowledge of ESD practitioners relating to the various tasks involved in the procedure. Three observations were conducted of expert ESD trainers either while they performed actual ESD procedures or at a training workshop. Interviews were either conducted over the phone or in person. Interview participants included four experts and four novices. The observation notes and interviews were analyzed for emergent qualitative themes and relationships.

RESULTS

The qualitative analysis yielded thematic insights related to four main cognition-related categories: learning goals/principles, challenges/concerns, strategies, and decision-making. The specific insights under each of these categories were systematically mapped to the various tasks inherent to the ESD procedure.

CONCLUSIONS

The CTA approach was applied to identify cognitive themes related to ESD procedural tasks. Insights developed based on the qualitative analysis of interviews and observations of ESD practitioners can be used to inform the design of ESD training systems, such as virtual reality-based simulators.

Cost analysis and outcome of endoscopic submucosal dissection for colorectal lesions in an outpatient setting

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD), a minimally invasive treatment for early gastrointestinal (GI) cancer, is considered challenging and risky in the colorectum. As such, most patients undergoing ESD are hospitalized due to the perceived increased risk of adverse events. The aim of this study was to compare the costs, safety and efficacy of colorectal-ESD in an outpatient vs inpatient setting in a tertiary level center.

METHODS

This is a retrospective study on consecutive patients admitted for colorectal-ESD. Patients were divided into outpatients (Group-A, same-day discharge), and inpatients (Group-B, admitted for at least one night). Data on overall costs, outcomes and adverse events were assessed for each group.

RESULTS

A total of 136 patients were considered. Fourteen were excluded because ESD was not performed due to intraprocedural suspicion of invasive cancer. Eighty-three patients were treated as outpatients (Group-A, 68%) and 39 (Group-B, 32%) were hospitalized. R0-rate was 90.4% in Group-A and 89.7% in Group-B(P = 0.98). One perforation occurred in Group-A (1.2%) and 2 in Group-B(5.1%, P = 0.2). Mean Length of stay (LOS) was 1 day for outpatients and 3.3 days for inpatients. Management of Group-A as outpatients produced a cost savings of 941€ on average per patient.

CONCLUSIONS

Outpatient colorectal-ESD is a feasible, cost-effective strategy to manage superficial colorectal tumors with outcomes comparable to inpatient colorectal-ESD. By using proper selection criteria, outpatient ESD could be considered the first-line approach for most patients.

Optimal processing of ESD specimens to avoid pathological artifacts

BACKGROUND

En bloc endoscopic submucosal dissection (ESD) has been recently introduced as a treatment for precancerous/neoplastic gastrointestinal conditions. The aim of the present study was histological assessment of en bloc ESD specimens.

METHODS

Fifty-three ESD specimens were positioned over a cellulose acetate support (40 specimens; 12 from the upper gastrointestinal tract and 28 from the lower gastrointestinal tract) or pinned with nails on polystyrene or cork (13 specimens; 7 from the upper gastrointestinal tract and 6 from the lower gastrointestinal tract). We cut consecutive 2 mm-thick sections stained with hematoxylin and eosin. From the first and the last sections, we obtained a second slide, after a 180° rotation and re-embedding. The quality of ESD samples was scored as inadequate, suboptimal and adequate, based on the amount of crushing, shearing and stretching artifacts that were scored from 0 (absent) to 2 (diffuse or maximum). From the sum of these we obtained a global artifact score (GAS).

RESULTS

Removed lesions were: adenocarcinoma (5 cases), neuroendocrine tumor (NET) G1 (1 case), premalignant conditions, including adenomatous polyps (41 cases) and hyperplastic lesions (6 cases). A positive deep surgical margin was found in 8/53 cases (15%): high- and low-grade dysplastic glands were detected in 5 cases, low-grade adenocarcinoma in 2, and NET cells in 1. Dysplastic glands were detected in the lateral surgical margins of 12 ESD specimens (23%). Among the ESD specimens positioned on the cellulose acetate support, apart from the modifications due to electrocoagulation, 2 (5%) showed shearing modifications. In the group of ESD specimens fixed with nails, 5 (38%) showed shearing, 10 (77%) crushing artifacts, 11 (85%) stretching and 11 (85%) multiple holes caused by the nails. On the basis of these data all histological specimens from ESD on cellulose acetate were adequate (GAS 0-1).However, in the group of ESD fixed with nails, 1 was adequate (GAS 0), 11 suboptimal (GAS 2-5) and 1 inadequate (GAS 6).

CONCLUSIONS

Specific devices including cellulose support and adequate sampling blocks can be helpful to perform accurate histological assessment of ESD specimens after en bloc ESD for precancerous/neoplastic gastrointestinal lesions, with complete analysis of the status of the margins and the entirely en bloc evaluation of the lesion.

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.

Ten quality indicators for endoscopic submucosal dissection: what should be monitored and reported to improve quality

In the last decade, endoscopic submucosal dissection (ESD) has become more popular in Asia and, more recently, also in Europe and North America, however the issue of quality control has never been raised. Therefore, there is an urgent need to identify possible quality indicators to monitor as part of internal audit process. This is particularly compelling, since the diffusion of ESD outside Asian, super-expert, high-volume, tertiary referral centers. In the current review, we raised the issue of quality control for ESD and proposed a list of ten possible quality indicators that should be monitored by each endoscopist and reported in every study reporting results on ESD procedures. We feel that these quality indicators should be used in clinical practice by endoscopists to benchmark the data with the internationally recommended standards.

Comparing outcomes for endoscopic submucosal dissection between Eastern and Western countries: A systematic review and meta-analysis

AIM

To compare endoscopic submucosal dissection (ESD) outcomes between Eastern and Western countries.

METHODS

A systematic review and meta-analysis was performed using PubMed, MEDLINE, Web of Science, CINAHL and EBM reviews to identify studies published between 1990 and February 2016. The primary outcome was the efficacy of ESD based on information about either curative resection, en bloc or R0 resection rates. Secondary outcomes were complication rates, local recurrence rates and procedure times.

RESULTS

Overall, 238 publications including 84318 patients and 89512 gastrointestinal lesions resected using ESD were identified. 90% of the identified studies reporting ESD on 87296 lesions were conducted in Eastern countries and 10% of the identified studies reporting ESD outcomes in 2216 lesions were from Western countries. Meta-analyses showed higher pooled percentage of curative, en bloc, and R0 resection in the Eastern studies; 82% (CI: 81%-84%), 95% (CI: 94%-96%) and 89% (CI: 88%-91%) compared to Western studies; 71% (CI: 61%-81%), 85% (CI: 81%-89%) and 74% (CI: 67%-81%) respectively. The percentage of perforation requiring surgery was significantly greater in the Western countries (0.53%; CI: 0.10-1.16) compared to Eastern countries (0.01%; CI: 0%-0.05%). ESD procedure times were longer in Western countries (110 min vs 77 min).

CONCLUSION

Eastern countries show better ESD outcomes compared to Western countries. Availability of local ESD expertise and regional outcomes should be considered for decision making to treat gastrointestinal lesions with ESD.

Using Endoscopic Submucosal Dissection as a Routine Component of the Standard Treatment Strategy for Large and Complex Colorectal Lesions in a Western Tertiary Referral Unit

BACKGROUND

Colorectal endoscopic submucosal dissection results in high rates of en bloc resection, few recurrences, and accurate diagnosis, and it is useful in lesions with significant fibrosis. However, endoscopic submucosal dissection has not been widely adopted by Western endoscopists and the published experience from Western centers is very limited.

OBJECTIVES

This study aims to report the outcomes from a UK tertiary center using colorectal endoscopic submucosal dissection as part of a standard lesion specific treatment approach.

DESIGN

This was a retrospective study.

SETTING

The study was conducted in a tertiary referral unit for interventional endoscopy in the United Kingdom.

PATIENTS

A total of 116 colorectal lesions were resected using endoscopic submucosal dissection or hybrid endoscopic submucosal dissection in 107 patients.

MAIN OUTCOME MEASURES

Outcomes included complications, recurrence, requirement for surgery, en bloc and R0 resection.

RESULTS

One hundred sixteen lesions (mean size 58.8mm) were resected using endoscopic submucosal dissection (n = 58) and hybrid endoscopic submucosal dissection (n = 58). Eighty-two (70.7%) had failed attempts at resection (n = 58) or extensive sampling before referral. Twelve contained invasive adenocarcinoma; endoscopic resection was curative in 6. Only 2 of 6 patients with noncurative endoscopic resection agreed to surgery, and none had lymph node metastases. Six of 7 perforations were successfully treated with endoscopic clips. Where endoscopic submucosal dissection was used alone, en bloc resection was achieved in 93% and R0 resection was achieved in 91%. Two patients experienced recurrence; both were managed with endoscopic resection.

LIMITATIONS

This was a retrospective study. Procedures were planned as endoscopic submucosal dissection, but some may have been converted to hybrid endoscopic submucosal dissection and not recorded.

CONCLUSION

Colorectal endoscopic submucosal dissection can be used in a Western center as part of a standard lesion-specific approach to deliver effective organ-conserving treatment to patients with large challenging lesions. Lesion assessment in Western practice should be improved to reduce the incidence of prior heavy manipulation and to guide appropriate referral. See Video Abstract at http://links.lww.com/DCR/A601.

Step-up training for colorectal and gastric ESD and the challenge of ESD training in the proximal colon: results from a German Center

BACKGROUND AND STUDY AIMS

The endoscopic submucosal dissection (ESD) of cancerous and precancerous lesions in the gastrointestinal (GI) tract is an effective but difficult-to-learn procedure, especially for Western endoscopists. We developed a step-up training protocol and evaluated its outcome on a single endoscopist using specific performance measures.

PATIENTS AND METHODS

The training protocol included a 12-month period of 50 observational and supervised ESD cases as well as 24 animal procedures. After completion of the protocol, ESD competency was evaluated in the first 30 independent ESD cases. Majority of lesions were located in the stomach and rectum. Performance measures included R0-resection rate, complication rate and resection speed.

RESULTS

R0 resection rate was 93 %, complication rate was 7 % and median resection speed was 6,77 cm ² /h. 1 case of delayed perforation with subsequent hemicolectomy occurred in the descending colon.

CONCLUSION

The ESD step-up training protocol used in this study on a single endoscopist showed excellent outcomes for lesions in the rectum and stomach. However, ESD training in the upper colon remains a challenge.

Endoscopic submucosal dissection in the West: Current status and future directions

Endoscopic submucosal dissection (ESD) was first conceptually described almost 30 years ago in Japan and is now widely practiced throughout East Asia. ESD expands the boundaries of endoscopic resection (ER) by allowing en bloc resection of large early neoplastic lesions within the gastrointestinal tract (GIT). This offers advantages over other ER techniques by facilitating definitive histological staging and curative treatment of early cancer in selected cases. Indeed, the experience of ESD in Eastern countries is significant, and excellent outcomes from high-volume centers are reported. The potential benefits of ESD are recognized by Western endoscopists, but its adoption has been limited. A number of factors contribute to this, including epidemiological differences in GIT neoplasia between Western and Eastern populations and limitations in training opportunities. In this review, we discuss the role of ESD, its current status and the future in Western endoscopic practice.

Robot assisted tumor resection devices

INTRODUCTION

In Japan, colorectal endoscopic submucosal dissection (ESD) is being conducted safely and effectively as shown by the increased number of the cases, however, it is still regarded as a complicated and challenging procedure. Therefore, piecemeal endoscopic mucosal resection (p-EMR) is still regarded as an appropriate treatment, rather than ESD for large colorectal tumors, especially in Western countries. Areas covered: There are several factors those are responsible for colorectal ESD difficulty. Firstly, there is no adequate traction or counter-traction in colorectal ESD. Secondly, it is challenging to handle the colonoscope in a redundant and narrow colonic lumen. Thirdly, the risk of perforation is estimated to be relatively higher compared to the stomach or esophagus Expert commentary: To overcome these difficulties, various traction and counter-traction methods have been reported and finally, the new concept of the Master and Slave Transluminal Endoscopic Robot (MASTER) has been developed and is soon to be available for clinical use. The authors have reviewed the history of colorectal ESD and MASTER in this paper.

Endoscopic full-thickness resection of superficial colorectal neoplasms using a new over-the-scope clip system: A single-centre study

BACKGROUND AND AIM

Endoscopic full-thickness resection (EFTR) provides complete en-bloc resection with a histopathological evaluation of submucosal, muscular, and serosal layers. The aim of this study was to investigate the efficacy and safety of a novel over-the-scope device for colorectal EFTR.

MATERIAL AND METHODS

In this retrospective, observational, open-label case study, a total of 20 patients with superficial colorectal neoplasms, underwent EFTR using a new endoscopic full-thickness resection device (FTRD; Ovesco Endoscopy, Tübingen, Germany). Endoscopic treatment outcomes (technical success, rate of EFTR, adverse events) and early follow-up at three months, were analyzed.

RESULTS

We reported a 100% of technical success, defined as full-thickness resection. Among the R1 resections, histology was negative for neoplasm. Non-lifting adenomas had histology positive for adenocarcinoma: seven T1/G1/sm1; one T1/G1/sm2; one, who underwent a surgical resection, T1/G1/sm3. Mean size of the resected lesions was 26mm, ranging from 10 to 42mm. One (5%) patient developed abdominal pain, fever and leukocytosis and was treated conservatively with medical therapy. In all specimens, histological complete resection was confirmed.

CONCLUSIONS

EFTR is a feasible and effective technique that could become a valid alternative to EMR and ESD in the management of recurrent adenomas, no-lifting lesions and scars of R1 resections. However, prospective studies are needed to further evaluate the device and technique.

Colorectal endoscopic submucosal dissection: predictors and neoplasm-related gradients of difficulty

BACKGROUND AND STUDY AIM

 The role of colorectal endoscopic submucosal dissection (ESD) is standardized in Japan and East Asia, but technical difficulties hinder its diffusion. The aim was to identify predictors of difficulty for each neoplasm type.

METHODS

 A competent operator performed all procedures. ESD difficulty was defined as: en bloc with a slow speed (< 0.07 cm ² /min; 30 × 30 mm neoplasm in > 90 min), conversion to endoscopic mucosal resection, or resection abandonment. Pre- and intraoperative difficulty variables were defined according to standard criteria, and evaluated separately for the rectum and colon. Difficulty predictors and gradients were evaluated by the multivariate logistic regression model.

RESULTS

 A total of 140 ESDs were included: 110 in the colon and 30 in the rectum. Neoplasms were laterally spreading tumors - granular type (LST-G) in 85 cases (61 %); the median longer axis was 30 mm (range 15 - 180 mm); a scar was present in 15 cases (11 %). ESD en bloc resection and difficulty rates were 85 % (n = 94) and 35 % (n = 39) in the colon, and 73 % (n = 22) and 50 % (n = 15) in the rectum ( P  = 0.17 and 0.28, respectively). The scar was the only preoperative predictor of difficulty in the rectum (odds ratio [OR] 12.3, 95 % confidence interval [CI] 1.27 - 118.36), whereas predictors in the colon were: scar (OR 12.7, 95 %CI 1.15 - 139.24), LST - nongranular type (NG) (OR 10.5, 95 %CI 1.20 - 55.14), and sessile polyp morphology (OR 3.1, 95 %CI 1.18 - 10.39). Size > 7 - ≤ 12 cm ² (OR 0.20, 95 %CI 0.06 - 0.74) and operator experience > 120 procedures (OR 0.19, 95 %CI 0.04 - 0.81) were predictors for a easy procedure. No intraoperative predictors of difficulty were identified in the rectum, whereas predictors in the colon were: severe submucosal fibrosis (OR 21.9, 95 %CI 2.11 - 225.64), ineffective submucosal exposure by gravity countertraction (OR 12.3, 95 %CI 2.43 - 62.08), and perpendicular submucosal dissection approach (OR 5.2, 95 %CI 1.07 - 25.03). When experience was /= 90, preoperative gradient of colonic ESD difficulty was the highest for LST-NGs (scar positive and negative up to 47 % and 20 %, respectively), intermediate for sessile polyps with scar (up to 23 %), and the lowest for LST-Gs (< 8 %). Different difficulty gradients between neoplasm types persisted with increasing experience: LST-NG rate up to 14 % after 120 procedures.

CONCLUSIONS

 Colonic and rectal ESD difficulty has qualitative differences. Preoperative predictors should be considered to identify the difficulty gradient of each neoplasm type and the appropriate setting for ESD.

The efficacy of endoscopic submucosal dissection for colorectal tumors extending to the dentate line

PURPOSE

Although endoscopic submucosal dissection (ESD) is becoming the mainstay of the treatment strategies, rather than surgical treatment, for colorectal tumors extending to the dentate line, ESD is technically more difficult. This study was aimed at assessing the usefulness of ESD for the treatment of colorectal tumors extending to the dentate line.

METHODS

This study included 531 patients with colorectal tumors who underwent colorectal ESD between 2008 and 2015. They were divided into three groups: rectal tumors extending to the dentate line (anorectal group), those not extending to the dentate line (proximal rectal group), and colonic tumors (colonic group), and a retrospective comparative analysis was carried out.

RESULTS

Of the total patients, 18 (3.4%) had lesions extending to the dentate line area. The procedure times were 103.4 ± 84.0, 80.4 ± 64.3, and 71.8 ± 52.3 min, respectively (P = 0.0318). All the patients in the anorectal group were operated by operators who had performed at least 20 colorectal ESDs (P < 0.0001). No significant difference among the three groups was found in the en bloc resection rate, complete resection rate, or curative resection rate. Although no significant difference in the incidence of perforation was observed among the three groups, intraoperative bleeding was observed in 61% of the patients in the anorectal group (P < 0.0001).

CONCLUSIONS

ESD is an effective treatment strategy for colorectal tumors extending to the dentate line. However, it seems that anorectal ESD, which is technically more difficult than colorectal ESD, should be performed by operators with ample experience in performing ESD.

Endoscopic submucosal dissection for large colorectal neoplasms

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) for colorectal neoplasms (CRN) of >50 mm is considered technically difficult. The ITknife nano™ was developed specifically for ESD of CRN and esophageal superficial neoplasms; however, only limited data are available regarding its use in this procedure. Here we assessed the safety and efficacy of ESD using the ITknife nano™ for large CRN (>50 mm).

METHODS

We carried out a retrospective study, including consecutive patients with CRN larger than 50 mm that were treated by ESD between September 2002 and August 2016 at our institution. To clarify features of the ITknife nano™ and to assess its safety and efficacy, we compared en bloc/curative resection rates, complications, and resection speed between ESD done using the Dual knife™ with and without the ITknife nano™.

RESULTS

We analyzed a total of 177 ESD-treated large CRN (median tumor size, 61 mm). Among the 133 CRN treated by ESD using the ITknife nano™, en bloc and curative resection rates were 96.2% and 80.5%, respectively. Perforation occurred in eight cases (6.0%) and delayed bleeding in four cases (3.0%). All complications were endoscopically managed. Resection speed was significantly faster for ESD using the ITknife nano™ (25.3 mm² /min) compared to using the Dual knife™ only (19.9 mm² /min; P = 0.02).

CONCLUSIONS

Use of the ITknife nano™ for ESD treatment of large CRN (>50 mm) is feasible and may contribute to reduced procedure times. Further controlled studies are needed to confirm these findings.

Endoscopic mucosal resection: learning curve for large nonpolypoid colorectal neoplasia

BACKGROUND AND AIMS

Colorectal EMR for nonpolypoid neoplasia achieves better outcomes when performed by expert endoscopists. The time point at which the endoscopist achieves expert level remains to be defined. The objective of this study was to establish a learning curve of colorectal EMR for nonpolypoid neoplasia based on residual tissue on surveillance colonoscopy and adverse event rate.

METHODS

Five hundred seventy-eight consecutive patients underwent EMR of colorectal neoplasia by 1 of 3 primary endoscopists between December 2004 and September 2013 in a tertiary academic center. Primary analyses focused on the largest lesion for patients with more than 1 lesion (median age, 69 years; median polyp size, 30 mm; 51% en bloc resection). Data on surveillance colonoscopy were available for 74%. Learning curves were calculated for each of the 3 main outcome measurements: the presence of residual neoplasia on surveillance colonoscopy, endoscopic assessment of incomplete EMR, and the occurrence of an immediate bleeding adverse event.

RESULTS

Residual neoplasia on surveillance colonoscopy was present for 23.2% of patients, the rate of endoscopist-assessed incomplete EMR was 27.6%, and immediate bleeding adverse events occurred in 6.9% of patients. Although there was between-endoscopist variability, the overall rates of residual neoplasia and incomplete EMR decreased to below 20% to 25% after 100 EMRs; initial decreases in both rates were observed for earlier EMRs. Immediate bleeding adverse events occurred at a low frequency for each endoscopist across all EMRs. Perforation requiring surgical intervention occurred in 1 patient (0.2%).

CONCLUSIONS

This study demonstrated that an unexpectedly high number of 100 colorectal EMR procedures for large nonpolypoid colorectal neoplasia are required to achieve a plateau phase for crucial outcomes.

Update on Difficult Polypectomy Techniques

Endoscopists often encounter colon polyps that are technically difficult to resect. These lesions traditionally were managed surgically, with significant potential morbidity and mortality. Recent advances in endoscopic techniques and instruments have allowed endoscopists to safely and effectively remove colorectal lesions with high technical and clinical success and potentially avoid invasive surgery. Endoscopic mucosal resection (EMR) has gained acceptance as the first-line therapy for large colorectal lesions. Endoscopic submucosal dissection (ESD) has been reported to be associated with higher rate of en bloc resection and less risk of short-time recurrence, but with an increased risk of adverse events. Therefore, the role of colorectal ESD should be restricted to lesions with high-risk morphologic features of submucosal invasion. In this article, we review the recent literature on the endoscopic management of difficult colorectal neoplasms.

Heterotopic gastric mucosa in the anus and rectum: first case report of endoscopic submucosal dissection and systematic review

BACKGROUND

Heterotopic gastric mucosa (HGM) is the most reported epithelial heterotopia, but it is very rare in the rectum and anus.

METHODS

The first case of an asymptomatic adult male with a large nonpolypoid HGM in the low rectum underwent complete resection by endoscopic submucosal dissection (ESD) is reported. The systematic review was based on a comprehensive search of MEDLINE, EMBASE and Google Scholar. Studies on humans were identified with the term 'heterotopic gastric mucosa in the rectum and /or anus.'

RESULTS

The search identified 79 citations, and 72 cases were evaluated comprising the present report. Congenital malformations were observed in 17 (24%) patients; rectal duplication accounted for most of the cases. The HGM was located in the anus and perineal rectum in 25 cases (41%) and low, middle and proximal pelvic rectum in 20 (33%), five (8%) and 11 cases (18%), respectively. Morphology was nonpolypoid in 37 cases (51%), polypoid in 26 cases (36%) and ulcerated in nine cases (13%). Specific anorectal symptoms were reported by 50 (69%) patients of the whole study population, and by 33 (97%) of 34 patients ≤ 18 years. Complications were observed in 23 cases (32%). The HGM was excised in 50 cases (83%). Endoscopic resection was performed in 17 cases (34%); resection was piecemeal in five of 12 lesions ≥15 mm, required argon plasma coagulation in two cases and was associated with residual tissue in two (17%). Intestinal metaplasia and an adenoma with low-grade dysplasia were described in three adults (4%).

DISCUSSION

This systematic review shows that the HGM in the rectum and anus may be associated with specific rectal symptoms and serious complications, mainly in the pediatric population, and a risk of malignancy in adults. Its complete excision should be recommended, and the ESD can overcome the technical limits of conventional endoscopic snare resection and avoid unnecessary surgery.

Endoscopic mucosal resection and endoscopic submucosal dissection of large colonic polyps

Almost all large and complex colorectal polyps can now be resected endoscopically. Piecemeal endoscopic mucosal resection (PEMR) is an established technique with fairly low complication risk and good short-term and medium-term outcomes. Several modifications to the basic injection and snare technique have been developed contributing to safer and more complete resections. Delayed bleeding requiring reintervention is the most troublesome complication in 2-7% of patients, particularly in those with comorbidities and large, right-sided polyps. Endoscopic submucosal dissection (ESD) has become popular in Japan and has theoretical advantages over PEMR in providing a complete, en bloc excision for accurate histological staging and reduced local recurrence. These advantages come at the cost of a more complex, expensive and time-consuming procedure with a higher risk of perforation, particularly early in the procedure learning curve. These factors have contributed to the slow adoption of ESD in the West and the challenge to develop new devices and endoscopic platforms that will make ESD easier and safer. Currently, ESD indications are limited to large rectal lesions, in which procedural complications are easily managed, and for colorectal polyps with a high risk of containing tiny foci of early submucosally invasive cancer, whereby ESD may be curative compared with PEMR.

Feasibility and safety of endoscopic submucosal dissection for lower rectal tumors with hemorrhoids

AIM: To evaluate the feasibility and safety of endoscopic submucosal dissection (ESD) for lower rectal lesions with hemorrhoids.

METHODS: The outcome of ESD for 23 lesions with hemorrhoids (hemorrhoid group) was compared with that of 48 lesions without hemorrhoids extending to the dentate line (non-hemorrhoid group) during the same study period.

RESULTS: Median operation times (ranges) in the hemorrhoid and non-hemorrhoid groups were 121 (51-390) and 130 (28-540) min. The en bloc resection rate and the curative resection rate in the hemorrhoid group were 96% and 83%, and they were 100% and 90% in the non-hemorrhoid group, respectively. In terms of adverse events, perforation and postoperative bleeding did not occur in both groups. In terms of the clinical course of hemorrhoids after ESD, the rate of complete recovery of hemorrhoids after ESD in lesions with resection of more than 90% was significantly higher than that in lesions with resection of less than 90%.

CONCLUSION: ESD on lower rectal lesions with hemorrhoids could be performed safely, similarly to that on rectal lesions extending to the dentate line without hemorrhoids. In addition, all hemorrhoids after ESD improved to various degrees, depending on the resection range.

Endoscopic mucosal resection and endoscopic submucosal dissection for colorectal lesions: A systematic review

AIM

To assess the efficacy and safety of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) for the treatment of colorectal lesions.

METHODS

A literature search was conducted from January 2000 to May 2015. The main outcomes were: recurrence after "en bloc" and "piecemeal" resection; procedure related adverse events; the EMR endoscopic success rate and the completely eradicated resection rate (R0) after ESD.

RESULTS

A total of 66 studies were included in the analysis. The total number of lesions was 17950 (EMR: 11.873; ESD: 6077). Recurrence rate was higher in the EMR than ESD group (765/7303l vs. 50/3910 OR 8.19, 95% CI 6.2-10.9 p<0.0001). EMR-en bloc resection was achieved in 6793/10803 lesions (62.8%) while ESD-en bloc resection was obtained in 5500/6077 lesions (90.5%) (OR 0.18, p<0.0001, 95% CI 0.16-0.2). Perforation occurred more frequently in ESD than in EMR group (p<0.0001, OR 0.19, 95% CI 0.15-0.24).

CONCLUSIONS

Endoscopic resection of large colorectal lesions is safe and effective. Compared with EMR, ESD results in higher "en bloc" resection rate and lower local recurrence rate, however ESD has high procedure-related complication rates.

Endoscopic mucosal resection (EMR) versus endoscopic submucosal dissection (ESD) for resection of large distal non-pedunculated colorectal adenomas (MATILDA-trial): rationale and design of a multicenter randomized clinical trial

Background

Endoscopic mucosal resection (EMR) is currently the most used technique for resection of large distal colorectal polyps. However, in large lesions EMR can often only be performed in a piecemeal fashion resulting in relatively low radical (R0)-resection rates and high recurrence rates. Endoscopic submucosal dissection (ESD) is a newer procedure that is more difficult resulting in a longer procedural time, but is promising due to the high en-bloc resection rates and the very low recurrence rates. We aim to evaluate the (cost-)effectiveness of ESD against EMR on both short (i.e. 6 months) and long-term (i.e. 36 months). We hypothesize that in the short-run ESD is more time consuming resulting in higher healthcare costs, but is (cost-) effective on the long-term due to lower patients burden, a higher number of R0-resections and lower recurrence rates with less need for repeated procedures.

Methods

This is a multicenter randomized clinical trial in patients with a non-pedunculated polyp larger than 20 mm in the rectum, sigmoid, or descending colon suspected to be an adenoma by means of endoscopic assessment. Primary endpoint is recurrence rate at follow-up colonoscopy at 6 months. Secondary endpoints are R0-resection rate, perceived burden and quality of life, healthcare resources utilization and costs, surgical referral rate, complication rate and recurrence rate at 36 months. Quality-adjusted-life-year (QALY) will be estimated taking an area under the curve approach and using EQ-5D-indexes. Healthcare costs will be calculated by multiplying used healthcare services with unit prices. The cost-effectiveness of ESD against EMR will be expressed as incremental cost-effectiveness ratios (ICER) showing additional costs per recurrence free patient and as ICER showing additional costs per QALY.

Discussion

If this trial confirms ESD to be favorable on the long-term, the burden of extra colonoscopies and repeated procedures can be prevented for future patients.

Trial registration

NCT02657044 (Clinicaltrials.gov), registered January 8, 2016.

Efficacy and safety of endoscopic resection of large colorectal polyps: a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of endoscopic resection of large colorectal polyps.

DESIGN

Relevant publications were identified in MEDLINE/EMBASE/Cochrane Central Register for the period 1966-2014. Studies in which ≥20 mm colorectal neoplastic lesions were treated with endoscopic resection were included. Rates of postendoscopic resection surgery due to non-curative resection or adverse events, as well as the rates of complete endoscopic removal, invasive cancer, adverse events, recurrence and mortality, were extracted. Study quality was ascertained according to Newcastle-Ottawa Scale. Forest plot was produced based on random effect models. I2 statistic was used to describe the variation across studies due to heterogeneity. Meta-regression analysis was also performed.

RESULTS

50 studies including 6442 patients and 6779 large polyps were included in the analyses. Overall, 503 out of 6442 patients (pooled rate: 8%, 95% CI 7% to 10%, I2=78.6%) underwent surgery due to non-curative endoscopic resection, and 31/6442 (pooled rate: 1%, 95% CI 0.7% to 1.4%, I2=0%) to adverse events. Invasive cancer at histology, non-curative endoscopic resection, synchronous lesions and recurrence accounted for 58%, 28%, 2.2% and 5.9% of all the surgeries, respectively. Endoscopic perforation occurred in 96/6595 (1.5%, 95% CI 1.2% to 1.7%) polyps, while bleeding in 423/6474 (6.5%, 95% CI 5.9% to 7.1%). Overall, 5334 patients entered in surveillance, 502/5836 (8.6%, 95% CI 7.9% to 9.3%) being lost at follow-up. Endoscopic recurrence was detected in 735/5334 patients (13.8%, 95% CI 12.9% to 14.7%), being an invasive cancer in 14/5334 (0.3%, 95% CI 0.1% to 0.4%). Endoscopic treatment was successful in 664/735 cases (90.3%, 95% CI 88.2% to 92.5%). Mortality related with management of large polyps was reported in 5/6278 cases (0.08%, 95% CI 0.01% to 0.15%).

CONCLUSIONS

Endoscopic resection of large polyps appeared to be an extremely effective and safe intervention. However, an adequate endoscopic surveillance is necessary for its long-term efficacy.

Meta-analysis comparing differing methods of endoscopic therapy for colorectal lesions

AIM: To compare the outcomes of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) of colorectal lesions.

METHODS: An electronic systematic literature search of four computerized databases was performed in July 2014 identifying studies reporting the outcomes of colorectal ESD and EMR. The primary outcome measures were en-bloc resection rate, endoscopic clearance rate and lesion recurrence rate of the patients followed up. The secondary outcome was the complication rate (including bleeding, perforation and surgery post EMR or ESD rate). Statistical pooling and random effects modelling of the studies calculating risk difference, heterogeneity and assessment of bias and quality were performed.

RESULTS: Six observational studies reporting the outcomes of 1324 procedures were included. The en-bloc resection rate was 50% higher in the ESD group than in the EMR group (95%CI: 0.17-0.83, P < 0.0001, I² = 99.7%). Endoscopic clearance rates were also significantly higher in the ESD group (95%CI: -0.06-0.02, P < 0.0001, I² = 92.5%). The perforation rate was 7% higher in the ESD group than the EMR group (95%CI: 0.05-0.09, P > 0.05, I² = 41.1%) and the rate of recurrence was 50% higher in the EMR group than in the ESD group (95%CI: 0.20-0.79, P < 0.001, I² = 99.5%). Heterogeneity remained consistent when subgroup analysis of high quality studies was performed (with the exception of piecemeal resection rate), and overall effect sizes remained unchanged for all outcomes.

CONCLUSION: ESD demonstrates higher en-bloc resection rates and lower recurrence rates compared to colorectal EMR. Differences in outcomes may benefit from increased assessment through well-designed comparative studies.

Endoscopic resection of colorectal lesions: The narrowing divide between East and West

Colonic polypectomy is an effective way of reducing colon cancer mortality. Multiple techniques now exist for the resection of polyps, and the endoscopist must decide on the appropriate resection approach for individual patients and lesions. This decision should maximize efficacy, safety and cost-effectiveness and provide optimal oncological outcomes while minimizing unnecessary surgical treatment. Advances in endoscopic imaging technology are improving the accuracy of endoscopic diagnosis and allowing more precise risk assessment of colonic lesions. Resection technique can be tailored to the endoscopic findings. Diminutive (≤5 mm) and small polyps (≤9 mm) are best resected primarily by snare techniques. Cold snare polypectomy has proven safety, but efficacy and technique require further study. There is variation in techniques used for polyps 6-20 mm in size and incomplete resection rates for conventional polypectomy may be considerable. Endoscopic mucosal resection (EMR) is well established, safe and effective for lesions without submucosal invasion (SMI); however, recurrence is a key limitation. Endoscopic submucosal dissection (ESD) is well established in the East; however, it is resource intensive and its role in lesions with a low risk of SMI is questionable. ESD in the West remains incompletely defined and is associated with high adverse event rates, but it is becoming increasingly available and successful as experience grows. Emerging full-thickness resection technologies are still in their infancy and remain experimental as a result of the absence of reliable closure devices and techniques. Patient-focused outcomes should guide technique selection.

Usefulness of training using animal models for colorectal endoscopic submucosal dissection: is experience performing gastric ESD really needed?

BACKGROUND AND STUDY AIMS

Despite the clinical advantages of colorectal endoscopic submucosal dissection (ESD), an effective training system, especially for Western endoscopists, has been challenging to establish. Herein, we propose a novel training program using ex vivo animal models and evaluate the learning curve of colorectal ESD trainees without gastric ESD experience.

PATIENTS AND METHODS

A total of 80 colorectal lesions were prospectively collected and removed by two novice operators. Before human ESD procedures, they received ESD training using an ex vivo porcine "proximal colon" model, which simulates a lumen with many folds and flexions. To assess the validity of our training system, the self-completion and en bloc R0 resection rates, the operation time, and prevalence of complications were compared between the first and latter period. Moreover the factors associated with prolonged operation time were evaluated.

RESULTS

The overall rates of self-completion and en bloc R0 resection were 98 % (78/80) and 100 % (80/80), respectively. The operation time during the first period was significantly longer than that during the latter period (86 ± 50 minutes vs. 60 ± 36 minutes, P = 0.01). Regarding complications, only two cases of perforations and delayed hemorrhage were observed during the first period; however, all of the complications were successfully managed endoscopically. The presence of fibrosis was identified as a significant independent predictor of a prolonged operation time during the first period (coefficient, 5.90; 95 %CI, 2.36 - 9.44, P = 0.002).

CONCLUSIONS

Our trainees achieved high rates of self-completion and R0 resection without severe complications even during the first 20 cases, suggesting that our training programs using ex vivo animal models are useful for trainees without gastric ESD experience.

STUDY REGISTRATION

UMIN000013566.