Learning curve associated with colorectal endoscopic submucosal dissection for endoscopists experienced in gastric endoscopic submucosal dissection

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.

Scissor-type knife significantly improves self-completion rate of colorectal endoscopic submucosal dissection: Single-center prospective randomized trial

BACKGROUND AND AIM

Colorectal endoscopic submucosal dissection (C-ESD) is recognized as a difficult procedure. Recently, scissors-type knives were launched to reduce the difficulty of C-ESD. The aim of this study was to evaluate the efficacy and safety of the combined use of a scissors-type knife and a needle-type knife with a water-jet function (WJ needle-knife) for C-ESD compared with using the WJ needle-knife alone.

METHODS

This was a prospective randomized controlled trial in a referral center. Eighty-five patients with superficial colorectal neoplasms were enrolled and randomly assigned to undergo C-ESD using a WJ needle-knife alone (Flush group) or a scissor-type knife-supported WJ needle-knife (SB Jr group). Procedures were conducted by two supervised residents. Primary endpoint was self-completion rate by the residents.

RESULTS

Self-completion rate was 67% in the SB Jr group, which was significantly higher than that in the Flush group (39%, P = 0.01). Even after exclusion of four patients in the SB Jr group in whom C-ESD was completed using the WJ needle-knife alone, the self-completion rate was significantly higher (63% vs 39%; P = 0.03). Median procedure time among the self-completion cases did not differ significantly between the two groups (59 vs 51 min; P = 0.14). No fatal adverse events were observed in either group.

CONCLUSIONS

In this single-center phase II trial, scissor-type knife significantly improved residents' self-completion rate for C-ESD, with no increase in procedure time or adverse events. A multicenter trial would be warranted to confirm the validity of the present study.

Feasibility of colorectal endoscopic submucosal dissection (ESD) carried out by endoscopists with no or little experience in gastric ESD

BACKGROUND AND AIM

Colorectal endoscopic submucosal dissection (ESD) is recommended to be carried out only by endoscopists with sufficient experience in gastric ESD. However, early gastric carcinoma is less common in Western countries than in Japan, and endoscopic maneuverability differs between the stomach and colorectum. We assessed the feasibility of colorectal ESD carried out by endoscopists with no or little experience in gastric ESD.

METHODS

We analyzed en bloc resection, R0 resection and perforation rates in 180 consecutive colorectal ESD carried out by three endoscopists who had no or <5 cases of experience in gastric ESD. We also identified factors associated with R0 resection failure.

RESULTS

Overall en bloc and R0 resection rates were 93.3% (168/180) and 82.2% (148/180), respectively. All 11 cases with perforation were treated endoscopically. Dividing 180 cases into three learning phases (early, middle, or late phases), the en bloc and R0 resection rates increased from 88.3% and 75.0% in the early phase to 98.3% and 88.3% in the late phase, respectively. Perforation rate also improved from 10.0% to 3.3%. Factors associated with R0 resection failure were location at junctions (odds ratio: 6.8, 95% CI: 1.9-27.5), preoperative factors reflecting fibrosis (5.8, 1.9-19.0), and late phase (0.2, 0.1-0.7).

CONCLUSION

Endoscopists without experience in gastric ESD carried out colorectal ESD safely. In the early and middle phases (≤40 cases), they should treat mainly rectal lesions but may also resect lesions in the colon avoiding flexures. Lesions located at junctions and those with preoperative factors reflecting fibrosis should be resected after completing 40 procedures.

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.

Clinical impact of endoscopic clip closure of perforations during endoscopic submucosal dissection for colorectal tumors

BACKGROUND AND AIMS

Despite advances in endoscopic submucosal dissection (ESD), perforation can still occur. The purpose of this study is to determine the clinical course and effectiveness of endoscopic closure in addition to the clinicopathologic features related to perforation.

METHODS

A total of 935 lesions in 900 consecutive patients between February 1998 and February 2013 underwent ESD for colorectal tumors at our institution. We studied the clinical course and histologic features of perforation through a matched case-control study that included 24 patients with intraprocedural perforation and 240 matched patients without perforation as a control group. Endoscopic closure by using through-the-scope endoclips was attempted in all cases of intraprocedural perforations immediately after perforation was recognized during the procedure.

RESULTS

Perforation occurred in 25 cases (2.7%), including 24 intraprocedural perforation and 1 delayed perforation. All but 1 patient with intraprocedural perforation was conservatively managed by endoscopic closure. One patient with unsuccessful endoscopic closure required emergency surgery. Analysis of clinical courses revealed statistically significant differences (P < .01) between the patients with perforation and the case-controlled, nonperforation patients in total procedure time, white blood cell count, and level of serum C-reactive protein on the day after the procedure, admission period, and fasting period. Both location (P = .027) and submucosal fibrosis (P = .04) of the lesion were significantly associated with perforation. Multivariate analysis revealed that fibrosis was a significant risk factor associated with perforation (odds ratio 2.86; 95% confidence interval, 1.03-7.90).

CONCLUSIONS

Endoscopic closure allows effective nonsurgical management in cases of intraprocedural perforation during ESD.

Learning curve for endoscopic submucosal dissection of esophageal neoplasms

There is a significant learning curve for endoscopic submucosal dissection of esophageal neoplasms that has not been fully characterized. This retrospective study included 33 consecutive superficial esophageal neoplasms for analysis of the learning curve for esophageal endoscopic submucosal dissection based on a single, novice endoscopist's experience. The study was divided into three periods (T1, T2, and T3) of 10 endoscopic submucosal dissection procedures in chronological order, with 13 procedures in the last period. Patient factors (age, sex, coexistent esophageal varices, or submucosal fibrosis) and tumor factors (location at upper esophagus, involving >3/4 esophageal circumference) for endoscopic submucosal dissection were not statistically different between the periods. The mean procedure time was 74.6 min/cm(2) , 23.4 min/cm(2) , and 10.5 min/cm(2) for T1, T2, and T3, respectively. The procedure time decreased over time (P = 0.02) and post hoc test revealed significant difference was only between T3 and T1 (P = 0.019). The en bloc resection rate was 50%, 100%, and 92.3% for T1, T2, and T3, respectively (P for trend = 0.015). R0 resection rate was 40%, 100%, and 84.6% for T1, T2, and T3, respectively (P for trend = 0.023). Two patients had complications: each one patient in T1 and T3 period experienced major bleeding during the procedure (P for trend = 0.875). None of the patients had esophageal perforation. The results of the study concluded that at least 30 cases of endoscopic submucosal dissection of esophageal neoplasms are needed for a novice endoscopist to gain early proficiency in this technique.

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.

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.

Propofol-Based Sedation Versus General Anesthesia for Endoscopic Submucosal Dissection

The main objective of this study is to evaluate general anesthesia or propofol-based sedation methods at gastric endoscopic submucosal dissection (ESD) procedures.The anesthetic method administered to cases undergoing upper gastrointestinal ESD between 2013 and 2015 was retrospectively investigated. Procedure time, lesion size, dissection speed, anesthesia time, adverse effects such as gag reflex, nausea, vomiting, cough, number of desaturation episodes (SpO2 < 90%), oropharyngeal suctioning requirements, hemorrhage, perforation, and amount of anesthetic medications were recorded.There were 54 and 37 patients who were administered sedation (group S) and general anesthesia (group G), respectively. The demographics of the groups were similar. The calculated dissection speed was significantly high in group G (36.02 ± 20.96 mm/min) compared with group S (26.04 ± 17.56 mm/min; P = 0.010). The incidence of nausea, cough, number of oropharyngeal suctioning, and desaturation episodes were significantly high in group S compared with that in group G (P < 0.5). While there was no difference between the groups in terms of hemodynamic parameters, in group S the use of propofol and in group G the use of midazolam and fentanyl were significantly higher (P < 0.05). Anesthesia time, postoperative anesthesia care unit, and hospital stay durations were not significantly different between the groups.General anesthesia increased dissection speed and enhanced endoscopist performance when compared with propofol-based sedation technique.

Preoperative indicators of failure of en bloc resection or perforation in colorectal endoscopic submucosal dissection: implications for lesion stratification by technical difficulties during stepwise training

BACKGROUND AND AIMS

The technical difficulties inherent in endoscopic submucosal dissection (ESD) for colorectal neoplasms may result in the failure of en bloc resection or perforation. The aim of this retrospective study was to assess the predictors of en bloc resection failure or perforation by using preoperatively available factors.

METHODS

Between September 2002 and March 2013, 716 colorectal ESDs in 673 consecutive patients were performed at a tertiary cancer center. Patient characteristics, tumor location, tumor type, colonoscopy-related factors, and endoscopist experience were assessed based on a prospectively recorded institutional ESD database. Logistic regression analysis was performed to identify predictors of failure of en bloc resection or perforations, with subgroup analyses of ESDs performed by endoscopists less experienced in colorectal ESD (<40 cases) and for colonic lesions only.

RESULTS

On multivariate analysis, independent predictors of failure of en bloc resection or perforations were the presence of fold convergence (odds ratio [OR] 4.4; 95% confidence interval [95% CI], 1.9-9.9), protruding type (OR 3.6; 95% CI, 1.8-7.1), poor endoscope operability (OR 3.5; 95% CI, 1.8-6.9), right-sided colonic lesions (OR 3.0; 95% CI, 1.5-6.3 vs rectal lesions), left-sided colonic lesions (OR 3.2; 95% CI, 1.7-6.3, vs rectal lesions), the presence of an underlying semilunar fold (OR 2.1; 95% CI, 1.3-3.6), and a less-experienced endoscopist (OR 2.1; 95% CI, 1.3-3.6). Among less-experienced endoscopists, colonic lesions were independent predictors (right-sided colonic lesions 8.1; 95% CI, 2.9-25.1; left-sided colonic lesions 8.1; 95% CI, 2.5-28.3 vs rectal lesions). For colonic lesions, the presence of fold convergence (OR 3.7; 95% CI, 1.6-8.6), poor endoscope operability (OR 3.6; 95% CI, 1.8-7.2), a less-experienced endoscopist (OR 3.0; 95% CI, 1.7-1.8), and the presence of an underlying semilunar fold (OR 2.7; 95% CI, 1.5-4.7) were identified predictors.

CONCLUSION

This study successfully identified predictors of en bloc resection failure or perforation. Understanding these indicators could help to accurately stratify lesions according to technical difficulty and to appropriately select endoscopists.

What is the best therapeutic strategy for colonoscopy of colorectal neoplasia? Future perspectives from the East

Development and improvement of endoscopic techniques and devices have changed the treatment of colorectal tumors over the last decade. For the treatment of diminutive polyps, the cold snare technique of the West is becoming a promising treatment in the East because of its short procedure time and low rate of delayed bleeding by eliminating the delayed effect of electrocautery. Rather than using piecemeal endoscopic mucosal resection or surgical resection for the treatment of large superficial tumors, the technique of the East of endoscopic submucosal dissection (ESD) achieves a high success rate of en bloc R0 resection, enabling detailed pathological evaluation with less invasive treatment. This procedure should also be useful in the West where large colorectal tumors are more frequent than in the East. Regarding outcomes, however, in the literature, the definition of 'curative resection' remains somewhat inconsistent and long-term outcomes of patients with deep submucosal and/or lymphovascular invasion in the en bloc specimen have not yet been determined. Large prospective, as well as retrospective, studies of these patients are warranted. When colorectal ESD is difficult because of size or location, the pocket-creation method and/or double-balloon-assisted technique may be useful. In the East, high-quality magnified chromoendoscopy is widely available, and endoscopists try to identify focal submucosal invasion. In the West, a systematic evaluation of surveillance for the prevention of colorectal cancer has been done and is highly refined. The East and West have much to learn from each other.

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.

Endoscopic submucosal dissection

ESD is an established effective treatment modality for premalignant and early-stage malignant lesions of the stomach, esophagus, and colorectum. Compared with EMR, ESD is generally associated with higher rates of en bloc, R0, and curative resections and a lower rate of local recurrence. Oncologic outcomes with ESD compare favorably with competing surgical interventions, and ESD also serves as an excellent T-staging tool to identify noncurative resections that will require further treatment. ESD is technically demanding and has a higher rate of adverse events than most endoscopic procedures including EMR. As such,sufficient training is critical to ensure safe conduct and high-quality resections. A standardized training model for Western endoscopists has not been clearly established,but will be self-directed and include courses, animal model training, and optimally an observership at an expert center.Numerous dedicated ESD devices are now available in the United States from different manufacturers. Although the use of ESD in the United States is increasing, issues related to technical difficulty, limited training opportunities and mentors, risk of adverse events, long procedure duration,and suboptimal reimbursement may limit ESD adoption in the United States to a modest number of academic referral centers for the foreseeable future.

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.

The Feasibility of Performing Colorectal Endoscopic Submucosal Dissection Without Previous Experience in Performing Gastric Endoscopic Submucosal Dissection

BACKGROUND

Experience in gastric endoscopic submucosal dissection (ESD) has been suggested as a prerequisite for performing colorectal ESD by some experts.

AIMS

To evaluate the feasibility of performing colorectal ESD without experience in gastric ESD.

METHODS

Between November 2009 and December 2013, ESD was attempted for 250 colorectal lesions by an endoscopist having extensive colonoscopy experience but no prior experience of gastric ESD. All attempts were categorized according to the chronological order of procedures: group 1, attempts 1-50; group 2, attempts 51-100; group 3, attempts 101-150; group 4, attempts 151-200; and group 5, attempts 201-250. Procedure-related outcomes were analyzed.

RESULTS

En bloc resection rate ≥80% was achieved after initial ten ESD attempts. The ESD success rate (72, 80, 90, 90, and 94% in group 1-5, respectively; p for trend = 0.001), perforation rate (14, 14, 6, 6, and 0% in group 1-5, respectively; p for trend = 0.003), and macroperforation rate (6, 6, 2, 2, and 0% in group 1-5, respectively; p for trend = 0.042) improved as experience accumulated. Performing >100 ESDs, rectal location, and absence of submucosal fibrosis were independent predictors of successful procedure.

CONCLUSION

Colorectal ESD can be safely and effectively performed by an endoscopist having extensive experience in colonoscopy-related procedures even without previous experience of gastric ESD. Meticulous case selection for ESD novice and active supervision by expert endoscopists during the initial learning period may minimize the risk of perforation.

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.

Learning curve analysis of colorectal endoscopic submucosal dissection (ESD) for laterally spreading tumors by endoscopists experienced in gastric ESD

BACKGROUND

Endoscopic submucosal dissection (ESD) for various colorectal neoplasms is more technically difficult than gastric ESD. We evaluated treatment outcomes and the learning curve for colorectal ESD of laterally spreading tumors (LSTs) based on the experience of a single endoscopist.

METHODS

We included 93 colorectal ESD procedures for colorectal LST that were performed between March 2009 and June 2012 by a single experienced endoscopist who previously performed hundreds of cases of gastric ESD. The cases were grouped chronologically into three periods by multi-dimensional analyses. For procedure time, the learning curve was analyzed using the moving average method, and for complication, the learning curve was analyzed using cumulative sum (cusum) method.

RESULTS

The median procedure time for 93 colorectal ESD was 45 min, and the rates of en bloc resection and R0 resection were 89.25 and 83.87 %. When results were compared among three periods in order to determine the learning curve, the procedure time and en bloc resection rates were not significantly different. However, the procedure proficiency (about 0.16 cm(2)/min) was significantly faster during the second period, after about 25 cases of colorectal ESD. In the third period (about 50 cases), the number and rate of en bloc resection (over 90 %) reached the same as that of en bloc R0 resection. When comparing outcomes based on LST subtype, the procedure proficiency of LST-granular type (LST-G) was significantly faster than that of LST-non granular type (LST-NG) (LST-NG, 0.072 cm(2)/min; LST-G, 0.157 cm(2)/min; p = 0.01).

CONCLUSION

Endoscopists fully experienced in gastric ESD need a relatively short learning period for colorectal ESD in terms of procedure time and complication. However, approximately 50 cases might be needed to acquire an adequate skill of colorectal ESD for LST in an experienced gastric ESD endoscopist. Colorectal ESD for LST-NG seems to have higher technical difficulty and a longer learning curve than LST-G.

Indications and Techniques for Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) allows for curative resection of superficial neoplasms of the gastrointestinal tract. Although ESD is the standard of care in Japan, its adoption in the West has been slow. Recent studies have shown the advantages of ESD over endoscopic mucosal resection, and as many of the barriers to ESD have been overcome, we are seeing an increasing interest in this technique. ESD can be used to treat superficial gastric, esophageal, and colorectal lesions. The most important pre-procedure step is estimating the depth of invasion of a lesion and by proxy the risk of lymph node metastasis. After a lesion has been resected, the histopathological analysis will determine whether the resection was curative or whether further surgery is needed. In conclusion, ESD is being more widely used in the West, and it is important to understand the indications, limitations, and techniques of ESD.

JGES guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection

Colorectal endoscopic submucosal dissection (ESD) has become common in recent years. Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also many types of precarcinomatous adenomas. It is important to establish practical guidelines in which the preoperative diagnosis of colorectal neoplasia and the selection of endoscopic treatment procedures are properly outlined, and to ensure that the actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with the 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 has recently compiled a set of colorectal ESD/endoscopic mucosal resection (EMR) guidelines using evidence-based methods. The guidelines focus on the diagnostic and therapeutic strategies and caveat before, during, and after ESD/EMR and, in this regard, exclude the specific procedures, types and proper use of instruments, devices, and drugs. Although eight areas, ranging from indication to pathology, were originally planned for inclusion in these guidelines, evidence was scarce in each area. Therefore, grades of recommendation were determined largely through expert consensus in these areas.

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.

Endoscopic submucosal dissection in gastric lesions: the 100 cases experience from a tertiary reference center in West

OBJECTIVE

Endoscopic submucosal dissection (ESD) is an endoscopic treatment method widely used in premalignant and malignant lesions in countries of the Far East. This method, which is difficult technically and has a high complication risk rate, has rarely been performed in the West, because of the fewer number of upper gastrointestinal lesions. In the present study, we aimed to present our results of gastric ESD procedures in respect to the learning curve.

METHODS

A total of 100 ESD procedures, which were performed in the stomach between April 2012 and September 2014, were recorded prospectively before and after the procedure. Patient data were analyzed retrospectively. ESD procedures were numbered chronologically; the first 30 patients constituted group 1, whereas the rest were classified as the group 2. ESD results were compared between the groups.

RESULTS

In a total of 95 patients, 100 gastric ESDs were performed. The overall en-bloc and complete resection rates were 93% and 92%, respectively. In respect of the learning curve, there were significant differences in the sizes of lesions and tissues obtained, procedure duration and dissection rate, snare use and knife preferences between groups (p = 0.002, p < 0.001, p = 0.003, p < 0.001, p = 0.009, and p < 0.001, respectively). No significant difference was detected in the en-bloc and complete resection rates and complications between the groups.

CONCLUSION

According to guideline recommendations and masters for ESD, if ESD training is initiated and continued, successful ESD may be performed in localized lesions in the stomach.

Untutored learning curve to establish endoscopic submucosal dissection on competence level

BACKGROUNDS/AIMS

Endoscopic submucosal dissection (ESD) of early cancer allows precise staging and avoids recurrence or surgery. Tutored by experts, ESD has rapidly spread in Japan, but still demands untutored learning in Western countries. A step-up approach starts with easiest gastric neoplasias, but fails on their low prevalence in Western countries. A prevalence-based approach includes challenging colonic neoplasias.

METHODS

We analyzed an untutored series of initial 50 ESD procedures by an experienced endoscopist on consecutive lesions referred according to prevalence.

RESULTS

Overall, 48 lesions (20% upper gastrointestinal, 80% colorectal; 2 hyperplastic (inflammatory) lesions, 46 neoplasms) were completely resected intention-to-treat with ESD, 2 required a second ESD. Neoplasias were resected 76% en-bloc (46% ESD, 30% ESD with snaring), 17% by ESD with snaring in 2-3 pieces, and 6.5% as ESD with snaring in multiple pieces. None of 15 neoplasias with high-grade intraepithelial neoplasia or an early esophageal cancer (R0) had recurred. Complications were 2 bleedings (4%) and 7 perforations (14%), 5 clipped and 2 (4%) operated. All patients were discharged within 9 days without long-term morbidity.

CONCLUSION

Untutored learning of ESD is feasible on colonic lesions. We propose to establish ESD in Europe with structured training and a prevalence-of-lesions-based approach.

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.

Factors predicting clinical outcomes of endoscopic submucosal dissection in the rectum and sigmoid colon during the learning curve

BACKGROUND AND STUDY AIMS

Colorectal endoscopic submucosal dissection (ESD) is associated with significant technical difficulty, long procedure time, and increased risk of complications, especially perforation. This study aimed to determine the factors associated with clinical results of ESD during the learning curve.

PATIENTS AND METHODS

In total, 44 patients with sessile and flat rectal and sigmoid colon lesions underwent ESD from November 2009 to September 2013. The procedure time, resection method, tumor size, location, gross morphology, presence of fibrosis, histologic findings, rates of en bloc and piecemeal resections and perforation were analyzed. The ESD procedure was classified as technically difficult in the case of procedure time > 120 minutes and/or piecemeal resection. The whole study time was divided into two periods: first period: resections 1 - 22, second period: resections 23 - 44.

RESULTS

En bloc and R0 resection have been achieved in 84.1 % of lesions. The mean procedure time was 119.95 ± 11.22 minutes (range 25 - 360 minutes). Perforation was seen in five cases (11.4 %). A larger tumor size was a risk factor for difficult ESD (P = 0.0001). A finding of fibrosis was a risk factor for piecemeal ESD (P = 0.0074), and perforation (P = 0.0012). There was a high direct positive correlation between tumor size and operation time (r = 0.83, P < 0.0001, 0.95 and 0.99 confidence interval for rho 0.71 - 0.904). There was no significant difference between the first and second period in terms of mean procedure time, en bloc resection or complication rate.

CONCLUSION

A larger tumor size was associated with technically difficult ESD. Severe submucosal fibrosis was a risk factor for both piecemeal resection and perforation.

Short-term outcomes of colorectal endoscopic submucosal dissection performed by trainees

BACKGROUND

Colorectal endoscopic submucosal dissection (ESD) is a relatively new therapy that has been accepted as the most effective treatment procedure for superficial colorectal neoplasms. Given the increasing acceptance and use of this procedure worldwide, the outcomes of colorectal ESD performed by trainees should be understood from a practical perspective and for developing strategies to introduce ESD to trainees. This study aimed to evaluate the clinical outcomes of ESD when conducted by less-experienced endoscopists.

SUMMARY

We retrospectively reviewed the clinical outcomes of 164 patients with 164 colorectal neoplasms who underwent ESD carried out by 20 trainees performing their first colorectal ESDs between April 2005 and March 2012. For each operator, clinical data were collected between the first and 30th cases. For evaluating the technical aspects of the ESD procedure, the endoscopic characteristics of the lesions, procedure time, en bloc resection rate, R0 resection rate, invasion depth and complications were evaluated. The median procedure time was 95 min; about 75% of the lesions were resected within 120 min. Apparent perforation or electric damage in the muscularis propria was seen in 4% of lesions. In terms of factors with the potential to effect procedure time, lesion size and pathological invasion depth were significantly different between shorter and longer treatment times for granular-type laterally spreading tumors (LST).

KEY MESSAGES

A granular-type LST of <40 mm is a good lesion for introducing colorectal ESD to trainees. Trainees should have a strong ability to make a depth diagnosis before starting ESD.

Treatment of large colorectal neoplasms by endoscopic submucosal dissection: a European single-center study

OBJECTIVE

Endoscopic submucosal dissection (ESD) has a high curative resection rate for gastrointestinal mucosal lesions, but is not used widely in Europe because of a high complication rate and a long learning curve. This study analyzed the ESD learning curve at a single European treatment center.

MATERIALS AND METHODS

ESD and hybrid-ESD (hESD) procedures were used to treat large colonic lesions that could not be resected in one piece by other endoscopic methods. Procedure duration and speed, and en-bloc, complete (R0) resection, and complication rates were analyzed.

RESULTS

Fifty-three patients underwent ESD (37 pure ESD, 16 hESD), most with rectal lesions (n=34, 64.2%). The mean lesion diameter was 3.7 ± 1.1 cm2 (range 2.0-7.0 cm), the median procedure duration was 70.0 min [interquartile range (IQR) 31.0-113.0 min], and the median treatment speed was 0.086 cm2/min (IQR 0.055-0.152). En-bloc and R0 resection rates were 86.5% (32/37) and 81.1% (30/37), respectively. Procedure speed increased significantly after about 25 cases (P=0.0313). The median hESD procedure treatment speed was 0.159 cm/min (n=16, IQR 0.094-0.193), which was better than with classical ESD (P=0.04). The hESD en-bloc and R0 resection rates were comparable to those of classical ESD (P>0.05). The only complication was bleeding, 5.7% (3/53); no perforation occurred. Recurrence was detected during follow-up (median 30.0 months, IQR 12-48) in one patient (1.7%).

CONCLUSION

ESD is useful and safe for resection of large colorectal polyps, and procedure speed increased considerably after 25 procedures. hESD was faster than ESD, with a high therapeutic resection rate.

Factors affecting the technical difficulty and clinical outcome of endoscopic submucosal dissection for colorectal tumors

BACKGROUND

Endoscopic submucosal dissection (ESD) for colorectal tumors is technically difficult due to the anatomy of the large intestine, with its narrow lumen, thin walls, and redundancy. Here, we assessed factors associated with incomplete resection and difficult colorectal ESD.

METHODS

Between November 2009 and April 2013, we performed ESD on 151 consecutive colorectal tumors in 147 patients. We evaluated the clinical outcomes of all cases and conducted multiple logistic regression analysis of the following factors related to incomplete resection and difficult procedure: age, gender, location (right colon, left colon or rectum), tumor size (diameter ≥40 or <40 mm), operation time, morphology [granular-type laterally spreading tumor (LST-G), non-granular-type laterally spreading tumor (LST-NG), or protruded type], fibrosis, and paradoxical movement during the procedure. A procedure that required more than 120 min was defined as a difficult colorectal ESD.

RESULTS

Average tumor size was 32.1 ± 10.7 mm, and the average procedure length was 71.8 ± 49.5 min. The rate of en bloc resection was 94.7%, while that of en bloc curative resection was 86.8%. Perforation occurred in 1.3% of the ESD procedures. Multivariate logistic regression analysis revealed that only severe fibrosis [odds ratio (OR) 4.51; 95% confidence interval (CI) 1.36-14.91, p = 0.014] contributed to incomplete resection and that a tumor size exceeding 40 mm (OR 5.73 [95% CI 1.66-19.74], p = 0.006), severe fibrosis (OR 23.31 [95% CI 6.59-82.54], p < 0.001), and paradoxical movement (OR 4.26 [95% CI 1.11-16.44], p = 0.035) were independent factors exacerbating the difficulty of colorectal ESD.

CONCLUSIONS

Severe fibrosis contributed to both incomplete resection and difficult colorectal ESD. Larger tumor size and paradoxical movement during the procedure were independent factors contributing to the difficulty of colorectal ESD. These factors might enable endoscopists to develop strategies for treating colorectal ESD.

Role of observation of live cases done by Japanese experts in the acquisition of ESD skills by a western endoscopist

AIM: To evaluate the role of observation of experts performing endoscopic submucosal dissection (ESD) in the acquisition of ESD skills.

METHODS: This prospective study is documenting the learning curve of one Western endoscopist. The study consisted of three periods. In the first period (pre-observation), the trainee performed ESDs in animal models in his home institution in the United States. The second period (observation) consisted of visit to Japan and observation of live ESD cases done by experts. The observation of cases occurred over a 5-wk period. During the third period (post-observation), the trainee performed ESD in animal models in a similar fashion as in the first period. Three animal models were used: live 40-50 kg Yorkshire pig, explanted pig stomach model, and explanted pig rectum model. The outcomes from the ESDs done in the animal models before and after observation of live human cases (main study intervention) were compared. Statistical analysis of the data included: Fisher’s exact test to compare distributions of a categorical variable, Wilcoxon rank sum test to compare distributions of a continuous variable between the two groups (pre-observation and post-observation), and Kruskal-Wallis test to evaluate the impact of lesion location and type of model (ex-vivo vs live pig) on lesion removal time.

RESULTS: The trainee performed 38 ESDs in animal model (29 pre-observation/9 post-observation). The removal times post-observation were significantly shorter than those pre-observation (32.7 ± 15.0 min vs 63.5 ± 9.8 min, P < 0.001). To minimize the impact of improving physician skill, the 9 lesions post-observation were compared to the last 9 lesions pre-observation and the removal times remained significantly shorter (32.7 ± 15.0 min vs 61.0 ± 7.4 min, P = 0.0011). Regression analysis showed that ESD observation significantly reduced removal time when controlling for the sequence of lesion removal (P = 0.025). Furthermore, it was also noted a trend towards decrease in failure to remove lesions and decrease in complications after the period of observation. This study did not find a significant difference in the time needed to remove lesions in different animal models. This finding could have important implications in designing training programs due to the substantial difference in cost between live animal and explanted organ models. The main limitation of this study is that it reflects the experience of a single endoscopist.

CONCLUSION: Observation of experts performing ESD over short period of time can significantly contribute to the acquisition of ESD skills.

Endoscopic Submucosal Dissection (ESD) in Colorectal Tumors

Background

Endoscopic submucosal dissection (ESD) – initially developed for the treatment of early gastric cancer in Japan – is an attractive option for en bloc resection of larger sessile or flat colorectal neoplasia.

Methods

A review of the current literature on colorectal ESD was carried out.

Results

In contrast to conventional endoscopic mucosal resection (EMR), ESD for larger colorectal neoplasia yields high en bloc resection rates and very low recurrence rates. The frequency of delayed bleeding is similar for EMR and ESD. Higher perforation rates during ESD are mostly due to microperforations identified and treated during the intervention, and are therefore of minor clinical relevance. A major disadvantage of ESD is the necessity for high-level endoscopic skills and long procedure times. ESD also has the potential to replace laparoscopic surgery or transanal endoscopic microsurgery mainly due to its lower complication rates.

Conclusion

ESD for the resection of larger flat or sessile colorectal lesions has potential advantages over conventional EMR or minimally invasive surgery. Due to the low incidence of early gastric cancer, experience with ESD will remain limited in Western countries. The spread of colorectal ESD will depend on adequate training opportunities and also on modifications yielding a reduction in procedure time.

Clinical practice of endoscopic submucosal dissection for early colorectal neoplasms by a colonoscopist with limited gastric experience

Objectives. Endoscopic submucosal dissection (ESD) for early colorectal neoplasms is regarded as a difficult technique and should commence after receiving the experiences of ESD in the stomach. The implementation of colorectal ESD in countries where early gastric cancer is uncommon might therefore be difficult. The aim is to delineate the feasibility and the learning curve of colorectal ESD performed by a colonoscopist with limited experience of gastric ESD. Methods. The first fifty cases of colorectal ESD, which were performed by a single colonoscopist between July 2010 and April 2013, were enrolled. Results. The mean of age was 64 (±9.204) years with mean size of neoplasm at 33 (±12.63) mm. The mean of procedure time was 70.5 (±48.9) min. The rates of en bloc resection, R0 resection, and curative resection were 86%, 86%, and 82%, respectively. Three patients had immediate perforation, but no patient developed delayed perforation or delayed bleeding. Conclusion. Our result disclosed that it is feasible for colorectal ESD to be performed by a colonoscopist with little experience of gastric ESD through satisfactory training and adequate case selection.

Training in endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) represents an important advancement in the therapy of early neoplastic gastrointestinal lesions by providing higher en-bloc curative resection rate with lower recurrence compared to endoscopic mucosal resection (EMR) and by sparing the involved organ and protecting patient’s quality of life. Despite these advantages ESD is associated with long procedure times and a higher rate of complications, making ESD a challenging procedure which requires advanced endoscopic skills. Thus, there has been a recognized need for structured training system for ESD to enhance trainee experience and, to reduce the risks of complications and inadequate treatment. ESD has a very flat learning curve. However, we do not have uniformly accepted benchmarks for competency. Nevertheless, it appears that, in Japan, more than 30 supervised gastric ESD procedures are required to achieve technical proficiency and minimize complications. A number of training algorithms have been proposed in Japan with the aim to standardize ESD training. These algorithms cannot be directly applied in the West due to substantial differences including the availability of highly qualified mentors, the type of pathology seen, choice of devices, and trainee’s background. We propose a training algorithm for Western physicians which integrates both hands-on training courses, animal model work as well as visits to expert centers. No specific preceptor training programs have been yet developed but there is a consensus that these programs are important for permeation of ESD worldwide.

Training in endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) represents an important advancement in the therapy of early neoplastic gastrointestinal lesions by providing higher en-bloc curative resection rate with lower recurrence compared to endoscopic mucosal resection (EMR) and by sparing the involved organ and protecting patient's quality of life. Despite these advantages ESD is associated with long procedure times and a higher rate of complications, making ESD a challenging procedure which requires advanced endoscopic skills. Thus, there has been a recognized need for structured training system for ESD to enhance trainee experience and, to reduce the risks of complications and inadequate treatment. ESD has a very flat learning curve. However, we do not have uniformly accepted benchmarks for competency. Nevertheless, it appears that, in Japan, more than 30 supervised gastric ESD procedures are required to achieve technical proficiency and minimize complications. A number of training algorithms have been proposed in Japan with the aim to standardize ESD training. These algorithms cannot be directly applied in the West due to substantial differences including the availability of highly qualified mentors, the type of pathology seen, choice of devices, and trainee's background. We propose a training algorithm for Western physicians which integrates both hands-on training courses, animal model work as well as visits to expert centers. No specific preceptor training programs have been yet developed but there is a consensus that these programs are important for permeation of ESD worldwide.

Endoscopy and polyps-diagnostic and therapeutic advances in management

Despite multiple efforts aimed at early detection through screening, colon cancer remains the third leading cause of cancer-related deaths in the United States, with an estimated 51000 deaths during 2013 alone. The goal remains to identify and remove benign neoplastic polyps prior to becoming invasive cancers. Polypoid lesions of the colon vary widely from hyperplastic, hamartomatous and inflammatory to neoplastic adenomatous growths. Although these lesions are all benign, they are common, with up to one-quarter of patients over 60 years old will develop pre-malignant adenomatous polyps. Colonoscopy is the most effective screening tool to detect polyps and colon cancer, although several studies have demonstrated missed polyp rates from 6%-29%, largely due to variations in polyp size. This number can be as high as 40%, even with advanced (> 1 cm) adenomas. Other factors including sub-optimal bowel preparation, experience of the endoscopist, and patient anatomical variations all affect the detection rate. Additional challenges in decision-making exist when dealing with more advanced, and typically larger, polyps that have traditionally required formal resection. In this brief review, we will explore the recent advances in polyp detection and therapeutic options.

Prevention and management of complications of and training for colorectal endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is reported to be an efficient treatment with a high rate of en bloc resection for large colorectal tumors in Japan and some other Western and Asian countries. ESD is considered less invasive than laparoscopic colectomy. However, ESD carries a higher risk of perforation than endoscopic mucosal resection (EMR). Various devices and training methods for colorectal ESD have been developed to solve the difficulties. In this review, we describe the complications of colorectal ESD and prevention of those complications. On the other hand, colorectal ESD is difficult for less-experienced endoscopists. The unique step-by-step ESD training system is performed in Japan. Additionally, appropriate training, including animal model training, for colorectal ESD should be acquired before working on clinical cases.

Peroral endoscopic esophageal myotomy: defining the learning curve

BACKGROUND

Peroral endoscopic myotomy (POEM) is an endoscopic alternative to laparoscopic esophageal myotomy. It requires a demanding skill set that involves both advanced endoscopic skills and knowledge of surgical anatomy and complication management.

OBJECTIVE

Determine the learning curve for POEM.

DESIGN

Prospective cohort study.

SETTING

Tertiary-care teaching hospital.

PATIENTS

The study involved the first 40 consecutive patients undergoing the POEM procedure under a prospective institutional review board protocol (research.gov #NCT01399476, 1056).

INTERVENTION

Peroral endoscopic myotomy for esophageal motility disorders.

MAIN OUTCOME MEASUREMENTS

Length of procedure (LOP) and technical errors (inadvertent mucosotomy).

RESULTS

A total of 40 patients underwent POEM. The mean LOP was 126 ± 41 minutes. The mean myotomy length was 9 cm (range, 6-20 cm). The LOP per centimeter myotomy and variability decreased as our experience progressed. The means (± standard deviation) of the LOP per centimeter myotomy were as follows: first cohort, 16 ± 4 minutes; second, 17 ± 5 minutes; third, 13 ± 3 minutes; fourth, 15 ± 2 minutes; and fifth, 13 ± 4 minutes. The incidence of inadvertent mucosotomy also decreased with increasing experience, to 8, 6, 4, 0, and 1, respectively. These minor complications were repaired intraoperatively with clips. There were 7 patients with capnoperitonium and another with bilateral capnothoraces that were associated with hemodynamic instability but resolved by Veress needle decompression. Two patients required endoscopy in the early postoperative period: self-limited hematemesis in one and radiologic evidence of leakage at the mucosotomy site in another.

LIMITATIONS

Nonrandomized study.

CONCLUSION

Mastery of operative technique in POEM is evidenced by a decrease in LOP, variability of minutes per centimeter of myotomy, and incidence of inadvertent mucosotomies and plateaus in about 20 cases for experienced endoscopists. The learning curve can be shortened with very close supervision and/or proctoring.

Current status of endoscopic resection strategy for large, early colorectal neoplasia in Japan

BACKGROUND

Conventional endoscopic resection (CER) for early colorectal neoplasia (CRN) is widely accepted as a minimally invasive treatment. Endoscopic submucosal dissection (ESD) was developed in Japan to resect larger lesions, but ESD was not covered by the Japanese national health insurance until April 2012. In addition, treatment strategies vary considerably among medical facilities. To evaluate the current situation in Japan regarding endoscopic treatment of CRNs measuring ≥20 mm, we conducted a prospective multicenter study at 18 medium-volume and high-volume specialized facilities in cooperation with the Japan Society for Cancer of the Colon and Rectum (JSCCR).

METHODS

The JSCCR conducted a multicenter, observational study of all patients treated by CER and ESD of CRNs measuring ≥20 mm.

RESULTS

From October 2007 to December 2010, CERs and ESDs were performed on 1,845 CRNs (CERs 1,029; ESDs 816). Lesions diagnosed as protruded, flat, and depressed totaled 541, 1224, and 48, respectively. En bloc resection rates and mean procedure times for CER/ESD were 56.9%/94.5% (P < 0.01) and 18 ± 23 min/96 ± 69 min, respectively. The average ESD procedure time was 129 ± 83 min in the ≥40-mm group. As lesion size increased, the CER en bloc resection rate decreased significantly (trend P < 0.01), but the ESD en bloc resection rate remained over 93%. Perforation and delayed bleeding rates of CER/ESD were 0.8%/1.6% (P < 0.05) and 2%/2.2% (P = 0.3), respectively.

CONCLUSIONS

The en bloc resection rate for ESD was significantly higher than for CER, although complication rates were fairly low. Despite a longer procedure time, safety of colorectal ESD has improved in various facilities in Japan. However, ESD for lesions measuring ≥40 mm must be performed by experienced endoscopists due to the longer procedure time.

Colorectal endoscopic submucosal dissection: is it suitable in western countries?

Endoscopic submucosal dissection (ESD) represents a significant advance in therapeutic endoscopy with the major advantage being the ability to achieve a higher en bloc resection rate for early stage lesions. Western endoscopists infrequently perform colorectal ESD (CR-ESD) because of the greater technical difficulty involved, longer procedure times, and increased risk of perforation. Specialized training and sufficient clinical experience are necessary to successfully perform ESDs, but a systematic education and training program has still not been established in Japan or elsewhere in the world. Experts generally acknowledge that the stomach is the first organ in which endoscopists should begin performing ESDs. The incidence and detection rates for early stage gastric cancer are significantly higher in Japan than in western countries, so Japanese endoscopists have a greater opportunity to perform gastric ESDs than their western counterparts. It is logical to ask, therefore, whether CR-ESD can be effectively applied in western countries. Based on a review of the relevant literature and our practical perspective, we have focused on the progress made in performing CR-ESD, its indications, training methods, and learning curve. Use of animal gastric and colon models is strongly recommended along with accumulating the necessary experience from the rectum to the colon on a step-by-step basis. It is reasonable to assume that an increasing number of CR-ESDs will be performed by western endoscopists in the foreseeable future given the continuing development of new techniques, and the refinement of instruments and other technologically advanced devices together with the creation of even more effective submucosal injection agents.

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

BACKGROUND

Endoscopic submucosal dissection (ESD) has revolutionized the resection of GI superficial neoplasms, but adoption in Western countries is significantly delayed.

OBJECTIVE

To evaluate a stepwise colorectal endoscopic submucosal dissection (ESD) learning and operative training protocol.

DESIGN

Prospective study in the Western setting.

SETTING

This study took place in a nonacademic hospital with one endoscopist expert in therapeutic endoscopy but novice in ESD.

PATIENTS

Indications for ESD were superficial neoplasms 20 mm and larger without ulcerations or fibrosis.

INTERVENTION

Training consisted of 5 unsupervised ESDs on isolated stomach, an observation period at an ESD expert Japanese center, 1 supervised ESD on isolated stomach, and retraining on 1 rectal ESD under supervision. The operative training on patients was performed without supervision moving from the rectum to the colon according to the competence achieved.

MAIN OUTCOME MEASUREMENTS

Competence was defined as an 80% en bloc resection rate plus a statistically significant reduction in operating time per square centimeter. Learning curves were calculated based on consecutive blocks of 5 procedures.

RESULTS

From February 2009 to February 2012, 30 rectal and 30 colonic ESDs were performed. The rectal ESD learning curve showed that the en bloc resection rate was 80% after 5 procedures (P = not significant); the operating time per square centimeter significantly decreased after 20 procedures (P = .0079); perforation occurred in 1 patient. The colonic ESD learning curve showed that the en bloc resection rate was 80% after 20 procedures (P = not significant); the operating time per square centimeter significantly decreased after 20 procedures (P = .031); perforations occurred in 2 patients.

LIMITATIONS

Single-center design.

CONCLUSIONS

A minimal intensive training seems sufficient for endoscopists expert in therapeutic procedures to take up ESD in a not overly arduous incremental method with separate and sequential learning curves for the rectum and colon.

What are the latest developments in colorectal endoscopic submucosal dissection?

Endoscopic submucosal dissection (ESD) enables direct submucosal dissection so that even large early-stage gastrointestinal tumors can be resected en bloc. ESD has recently been applied to the colorectum since it was originally developed for use in the stomach. However, colorectal ESD is technically more difficult with an increased risk of perforation compared with gastric ESD. In addition, this procedure is seldom performed in Western countries. Consequently, further technical advances and the availability of a suitable clinical training system are required for the extensive use of colorectal ESD. In this topic highlight, we review the most recent developments in colorectal ESD.

Effective training system in colorectal endoscopic submucosal dissection

Although colorectal endoscopic submucosal dissection (ESD) is superior to endoscopic mucosal resection (EMR) in en bloc resection rate, it is technically quite difficult because of the anatomical and histological characteristics of the colorectal wall. This difficulty prevents wide spread of the technique. Establishment of the training system for colorectal ESD is necessary to standardize training and to achieve wider acceptance of this technique. Herein, we describe our training system for colorectal ESD, and assess the validity of the training system for colorectal ESD, based on the clinical outcomes and learning curve of trainees. Our training system for colorectal ESD would help the spread of this procedure.