Benefits of endoscopic submucosal dissection according to size and location of gastric neoplasm, compared with conventional mucosal resection

Effect of endoscopic mucosal resection and endoscopic submucosal dissection on postoperative wound complications in patients with gastric cancer: A meta-analysis

Endoscopic submucosa dissection (ESD) allows complete excision of the whole lesion, which results in a higher percentage of complete excision and an improved quality of life by minimizing the amount of excision as opposed to an endoscopic mucosal resection (EMR). Although ESD is now being carried out in the majority of hospitals, ESD's possible complications (such as trauma and perforation) have given rise to doubts about ESD practices in patients with early-stage stomach cancer when deciding on therapy and reimbursement. This study was designed to evaluate the effectiveness and safety of ESD over EMR in treating early-stage stomach cancer. Four main databases have been searched, including EMBASE and published. The ROBINS-I tool suggested in the Cochrane Handbook has been applied to evaluate the quality of the chosen trials. It may better reflect the risk of bias in the included studies. The meta-analyses were carried out with ReMan 5.3, and the results were treated with endote. Seven cohort studies have been completed. Meta analysis indicated that EMR and ESD surgery did not differ significantly from each other in terms of postoperative haemorrhage (OR, 0.76; 95%CI, 0.56,1.04 p = 0.09); EMR, however, was associated with a lower rate of postoperative perforation than ESD surgery (OR, 0.36; 95%CI, 0.24,0.54 p < 0.0001). Taking into account that ESD and EMR did not differ significantly in the risk of wound bleeding, even though the risk of perforation is not likely to result in life-threatening illness. In the analysis of these data, however, the potential advantages of EMR might be greater than ESD.

American Society for Gastrointestinal Endoscopy guideline on endoscopic submucosal dissection for the management of early esophageal and gastric cancers: methodology and review of evidence

This document from the American Society for Gastrointestinal Endoscopy (ASGE) provides a full description of the methodology used in the review of the evidence used to inform the final guidance outlined in the accompanying Summary and Recommendations document regarding the role of endoscopic submucosal dissection (ESD) in the management of early esophageal and gastric cancers. This guideline used the Grading of Recommendations, Assessment, Development and Evaluation framework and specifically addresses the role of ESD versus EMR and/or surgery, where applicable, for the management of early esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), and gastric adenocarcinoma (GAC) and their corresponding precursor lesions. For ESCC, the ASGE suggests ESD over EMR for patients with early-stage, well-differentiated, nonulcerated cancer >15 mm, whereas in patients with similar lesions ≤15 mm, the ASGE suggests either ESD or EMR. The ASGE suggests against surgery for such patients with ESCC, whenever possible. For EAC, the ASGE suggests ESD over EMR for patients with early-stage, well-differentiated, nonulcerated cancer >20 mm, whereas in patients with similar lesions measuring ≤20 mm, the ASGE suggests either ESD or EMR. For GAC, the ASGE suggests ESD over EMR for patients with early-stage, well or moderately differentiated, nonulcerated intestinal type cancer measuring 20 to 30 mm, whereas for patients with similar lesions <20 mm, the ASGE suggests either ESD or EMR. The ASGE suggests against surgery for patients with such lesions measuring ≤30 mm, whereas for lesions that are poorly differentiated, regardless of size, the ASGE suggests surgical evaluation over endosic approaches.

American Society for Gastrointestinal Endoscopy guideline on endoscopic submucosal dissection for the management of early esophageal and gastric cancers: summary and recommendations

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy (ASGE) provides an evidence-based summary and recommendations regarding the role of endoscopic submucosal dissection (ESD) in the management of early esophageal and gastric cancers. It is accompanied by the document subtitled "Methodology and Review of Evidence," which provides a detailed account of the methodology used for the evidence review. This guideline was developed using the Grading of Recommendations, Assessment, Development and Evaluation framework and specifically addresses the role of ESD versus EMR and/or surgery, where applicable, for the management of early esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), and gastric adenocarcinoma (GAC) and their corresponding precursor lesions. For ESCC, the ASGE suggests ESD over EMR for patients with early-stage, well-differentiated, nonulcerated cancer >15 mm, whereas in patients with similar lesions ≤15 mm, the ASGE suggests either ESD or EMR. The ASGE suggests against surgery for such patients with ESCC, whenever possible. For EAC, the ASGE suggests ESD over EMR for patients with early-stage, well-differentiated, nonulcerated cancer >20 mm, whereas in patients with similar lesions measuring ≤20 mm, the ASGE suggests either ESD or EMR. For GAC, the ASGE suggests ESD over EMR for patients with early-stage, well- or moderately differentiated, nonulcerated intestinal type cancer measuring 20 to 30 mm, whereas for patients with similar lesions <20 mm, the ASGE suggests either ESD or EMR. The ASGE suggests against surgery for patients with such lesions measuring ≤30 mm, whereas for lesions that are poorly differentiated, regardless of size, we suggest surgical evaluation over endoscopic approaches.

Global research trends of endoscope in early gastric cancer: A bibliometric and visualized analysis study over past 20 years

Objectives

Early gastric cancer (EGC) is defined as aggressive gastric cancer involving the gastric mucosa and submucosa. Early detection and treatment of gastric cancer are beneficial to patients. In recent years, many studies have focused on endoscopic diagnosis and therapy for EGC. Exploring new methods to analyze data to enhance knowledge is a worthwhile endeavor, especially when numerous studies exist. This study aims to investigate research trends in endoscopy for EGC over the past 20 years using bibliometric analysis.

Methods

Original articles and reviews examining the use of endoscopy for EGC published from 2000 to 2022 were retrieved from the Web of Science Core Collection, and bibliometric data were extracted. Microsoft Office Excel 2016 was used to show the annual number of published papers for the top 10 countries and specific topics. VOSviewer software was used to generate network maps of the cooccurrences of keywords, authors, and topics to perform visualization network analysis.

Results

In total, 1,009 published papers met the inclusion criteria. Japan was the most productive country and had the highest number of publications (452, 44.8%), followed by South Korea (183, 18.1%), and China (150, 14.9%). The National Cancer Center of Japan was the institution with the highest number of publications (48, 4.8%). Ono was the most active author and had the highest number of cited publications. Through the network maps, exploring endoscopic diagnosis and therapy were major topics. Artificial intelligence (AI), convolutional neural networks (CNNs), and deep learning are hotspots in endoscopic diagnosis. Helicobacter pylori eradication, second-look endoscopy, and follow-up management were examined.

Conclusions

This bibliometric analysis investigated research trends regarding the use of endoscopy for treating EGC over the past 20 years. AI and deep learning, second-look endoscopy, and management are hotspots in endoscopic diagnosis and endoscopic therapy in the future.

A retrospective analysis based on multiple machine learning models to predict lymph node metastasis in early gastric cancer

Background

Endoscopic submucosal dissection has become the primary option of treatment for early gastric cancer. However, lymph node metastasis may lead to poor prognosis. We analyzed factors related to lymph node metastasis in EGC patients, and we developed a construction prediction model with machine learning using data from a retrospective series.

Methods

Two independent cohorts’ series were evaluated including 305 patients with EGC from China as cohort I and 35 patients from Spain as cohort II. Five classifiers obtained from machine learning were selected to establish a robust prediction model for lymph node metastasis in EGC.

Results

The clinical variables such as invasion depth, histologic type, ulceration, tumor location, tumor size, Lauren classification, and age were selected to establish the five prediction models: linear support vector classifier (Linear SVC), logistic regression model, extreme gradient boosting model (XGBoost), light gradient boosting machine model (LightGBM), and Gaussian process classification model. Interestingly, all prediction models of cohort I showed accuracy between 70 and 81%. Furthermore, the prediction models of the cohort II exhibited accuracy between 48 and 82%. The areas under curve (AUC) of the five models between cohort I and cohort II were between 0.736 and 0.830.

Conclusions

Our results support that the machine learning method could be used to predict lymph node metastasis in early gastric cancer and perhaps provide another evaluation method to choose the suited treatment for patients.

Analysis of risk factors for post-endoscopic papillectomy bleeding

BACKGROUND

Endoscopic papillectomy (EP) is an effective treatment for ampullary lesions but technically challenging because of anatomical specificities concerning the high rate of adverse events. Bleeding is one of the most feared complications and can be potentially life-threatening.

AIM

To study the risk factors for bleeding after EP are presented with the goal of establishing preventive measures.

METHODS

A total of 173 consecutive patients with ampullary lesions undergone EP from January 2006 to October 2020 were enrolled in this study. They were divided into a bleeding group and a non-bleeding group depending on whether postoperative bleeding occurred. Related factors were analyzed by univariate and multivariate logistics regression.

RESULTS

Postoperative bleeding was experienced in 33 patients (19.07%). Multivariate analysis also identified intraoperative bleeding (OR: 4.38, 95% CI: 1.87-11.15, p = .001) and endoscopic closure (OR: 0.25, 95% CI: 0.10-0.58, p = .001) as independent factors significantly associated with bleeding after EP. Lesion size (≥3 cm) was shown as an independent factor significantly associated with intraoperative bleeding (OR: 4.25, 95% CI: 1.21-16.44, p = .028).

CONCLUSIONS

This retrospective evaluation found that endoscopic closure was associated with reduced risk and intraoperative bleeding with increased risk of bleeding after EP. Lesion size may indirectly influence the risk of postoperative bleeding by increasing the risk of intraoperative bleeding.

Feasibility of ultrathin endoscope for esophageal endoscopic submucosal dissection

Background and study aims  Endoscopic submucosal dissection (ESD) is widely performed for superficial esophageal cancer, but stricture after extensive resection is a major clinical problem. Using an ultrathin endoscope would enable endoscopists to approach lesions beyond the stricture. We evaluated the feasibility of an ultrathin endoscope for esophageal ESD. Methods  To perform ESD with an ultrathin endoscope, we developed a transparent hood and ESD knife. A total of 24 esophageal ESDs were performed by two endoscopists with excised and live porcine esophaguses. A GIF-Q260 J and Dual knife were used in the conventional group and the GIF-XP260NS and a newly developed knife were used in the ultrathin group. En bloc resection rates, perforation rates, and procedure times were compared. Results  All 24 lesions were resected en bloc without perforation. The mean procedure time was longer in the ultrathin group, although not significantly so (274.3 ± 81.8 s vs 435.8 ± 313.9 s, respectively; P  = 0.22). Conclusion  Although the procedure time was longer in the ultrathin group, en bloc resection was performed without any perforation. The findings indicate that esophageal ESD with an ultrathin endoscope is feasible.

Long-term relapse-free treatment with endoscopic submucosal dissection combined with magnifying narrow-band imaging for a pregnant patient with flat-type condyloma acuminatum: a case report

Condyloma acuminatum, in the form of genital warts, usually results from an infection by human papillomavirus, one of the most common causes of sexually transmitted diseases. It develops after an incubation period of 3 weeks to 8 months after infection; flat lesions are significantly rare. Condyloma acuminatum is prevalent in the genitals, particularly in the anus of immunodeficient patients. This also occurs in women during menstrual period and pregnancy. Although a common treatment option for rectal and anal lesions, surgical resection is highly invasive and results in a high rate of recurrence. Recently, endoscopic submucosal dissection has been performed for anorectal lesions, but data on its long-term follow-up are not available. We report the case of an immunocompromised patient due to pregnancy who remained recurrence-free 27 months after en-bloc resection by endoscopic submucosal dissection, with adequate visualisation of the flat lesion's safety margin, combined with magnifying narrow-band imaging.

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer (second edition)

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society, in collaboration with the Japanese Gastric Cancer Association, produced "Guidelines for Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Early Gastric Cancer" in 2014, as a set of basic guidelines in accordance with the principles of evidence-based medicine. At the time, a number of statements had to be established by consensus (the lowest evidence level), as evidence levels remained low for many specific areas in this field. However, in recent years, the number of well-designed clinical studies has been increasing. Based on new findings, we have issued the revised second edition of the above guidelines that cover the present state of knowledge. These guidelines are divided into the following seven categories: indications, preoperative diagnosis, techniques, evaluation of curability, complications, long-term postoperative surveillance, and histology.

Consensus statement of the Hellenic and Cypriot Gastric Cancer Study Group on the diagnosis, staging and management of gastric cancer

Gastric Cancer epidemics have changed over recent decades, declining in incidence, shifting from distal to proximal location, transforming from intestinal to diffuse histology. Novel chemotherapeutic agents combined with modern surgical operations hardly changed overall disease related survival. This may be attributed to a substantial inherent geographical variation of disease genetics, but also to a failure to standardize and implement treatment protocols in clinical practice. To overcome these drawbacks in Greece and Cyprus, a Gastric Cancer Study Group under the auspices of the Hellenic Society of Medical Oncology (HeSMO) and Gastrointestinal Cancer Study Group (GIC-SG) merged their efforts to produce a consensus considering ethnic parameters of healthcare system and the international proposals as well. Utilizing structured meetings of experts, a consensus was reached. To achieve further consensus, statements were subjected to the Delphi methodology by invited multidisciplinary national and international experts. Sentences were considered of high or low consensus if they were voted by ≥ 80%, or < 80%, respectively; those obtaining a low consensus level after both voting rounds were rejected. Forty-five statements were developed and voted by 71 experts. The median rate of abstention per statement was 9.9% (range: 0-53.5%). At the end of the process, one statement was rejected, another revised, and all the remaining achieved a high consensus. Forty-four recommendations covering all aspects of the management of gastric cancer and concise treatment algorithms are proposed by the Hellenic and Cypriot Gastric Cancer Study Group. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and individualization are emphasized.

Multibending scope use for reduction of perforation risks in endoscopic submucosal dissection

AIMS

To identify areas that are difficult to access by the single scope at the time of endoscopic submucosal dissection (ESD) and examine the effectiveness, en-bloc, R0 resection, and perforation rate after changing to multibending scope at the same site.

MATERIAL AND METHODS

When the direct visualization of the submucosal layer became impossible with Q260J or in the position where the device became vertical and peeling became impossible in parallel, we decided to change to the multibending 2TQ260M scope to record the position where the change was effective and the perforation rate.

RESULTS

A total of 315 lesions were studied. Of the 12 sites, ESD was completed using the Q260J alone at four sites. The 2TQ260M scope was used with greater frequency at the fornix (88.9%) and on the line of the lesser curvature of the stomach (37.1%). In the cases with observed perforations (0.9%), the submucosal layer was not elevated due to the adhesion caused by strong fibrosis. None of the cases involving the change to 2TQ260M was ineffective, nor were perforations observed, and all resected specimens were en-bloc and R0 resections.

CONCLUSIONS

The success rate of this scope may help clinicians perform ESD with greater understanding.

Endoscopic submucosal dissection versus endoscopic mucosal resection for patients with early gastric cancer: a meta-analysis

OBJECTIVES

To investigate the treatment effects of endoscopic submucosal dissection (ESD) versus endoscopic mucosal resection (EMR) for early gastric cancer (EGC).

DESIGN

Meta-analysis.

METHODS

We systematically searched three electronic databases, including PubMed, EmBase and the Cochrane library for studies published with inception to January 2018. The eligible studies should be evaluated for the efficacy and safety of ESD versus EMR for patients with EGC. The summary ORs and standard mean differences (SMDs) with 95% CIs were employed as effect estimates. Sensitivity analyses were conducted to evaluate the impact of single study on overall analysis. Subgroup analyses were performed for investigated outcomes to evaluate the treatment effects of ESD versus EMR for patients with EGC with specific subsets.

RESULTS

Eighteen studies, with a total of 6723 patients with EGC, were included in final analysis. The summary ORs indicated that patients with EGC who received ESD were associated with an increased incidence of en bloc resection (OR: 9.00; 95% CI: 6.66 to 12.17; p<0.001), complete resection (OR: 8.43; 95% CI: 5.04 to 14.09; p<0.001) and curative resection (OR: 2.92; 95% CI: 1.85 to 4.61; p<0.001) when compared with EMR. Furthermore, ESD was associated with lower risk of local recurrence (OR: 0.18; 95% CI: 0.09 to 0.34; p<0.001). In addition, there was no significant difference between ESD and EMR for the risk of bleeding (OR: 1.26; 95% CI: 0.88 to 1.80; p=0.203). Though, ESD was correlated with greater risk of perforation (OR: 2.55; 95% CI: 1.48 to 4.39; p=0.001), and longer operation time (SMD: 1.12; 95% CI: 0.13 to 2.10; p=0.026) as compared with EMR. Additionally, several different features observed in included studies and patients could bias the effectiveness of ESD versus EMR in patients with EGC.

CONCLUSIONS

ESD is superior than EMR for en bloc resection, complete resection, curative resection and local recurrence, while it increased perforation risk and longer operation time.

Management of adverse events related to endoscopic resection of upper gastrointestinal neoplasms: Review of the literature and recommendations from experts

Prevention therapy is recommended for lesions >1/2 of the esophageal circumference. Locoregional steroid injection is recommended for lesions >1/2-3/4 of the esophageal circumference and oral steroids are recommended for lesions >1/2 of the subtotal circumference. For lesions of the entire circumference, oral steroid combined with injection steroid is considered. Endoscopic balloon dilatation (EBD) is the first choice of treatment for stricture after esophageal endoscopic submucosal dissection (ESD). Radical incision and cutting or self-expandable metallic stent can be considered for refractory stricture after EBD. In case of intraoperative perforation during esophageal ESD, endoscopic clip closure should be initially attempted. Surgery is considered for treatment of delayed perforation. Current standard practice for prevention of delayed bleeding after gastric ESD includes prophylactic coagulation of vessels on post-ESD ulcers and giving proton pump inhibitors. Chronic kidney disease stage 4 or 5, multiple antithrombotic drug use, anticoagulant use, and heparin bridging therapy are high-risk factors for delayed bleeding after gastric ESD. Intraoperative perforation during gastric ESD is initially managed by endoscopic clip closure. If endoscopic clip closure is difficult, other methods such as over-the-scope clip (OTSC), polyglycolic acid (PGA) sheet shielding etc. are attempted. Delayed perforation usually requires surgical intervention, but endoscopic closure by OTSC or PGA sheet may be considered. Resection of three-quarters of the circumference is a risk factor for stenosis after gastric ESD. Giving prophylactic local steroid injection and/or oral steroid is reported, but effectiveness has not been fully verified as has been done for esophageal stricture. The main management method for gastric stenosis is EBD but it may cause perforation.

Secondary endoscopic submucosal dissection for locally recurrent or incompletely resected gastric neoplasms

AIM

To investigate the feasibility and safety of secondary endoscopic submucosal dissection (ESD) for residual or locally recurrent gastric tumors.

METHODS

Between 2010 and 2017, 1623 consecutive patients underwent ESD for gastric neoplasms at a single tertiary referral center. Among these, 28 patients underwent secondary ESD for a residual or locally recurrent tumor. Our analysis compared clinicopathologic factors between primary ESD and secondary ESD groups.

RESULTS

The en bloc resection and curative rate of resection of secondary ESD were 92.9% and 89.3%, respectively. The average procedure time of secondary ESD was significantly longer than primary ESD (78.2 min vs 55.1 min, P = 0.004), and the adverse events rate was not significantly different but trended slightly higher in the secondary ESD group compared to the primary ESD group (10.7% vs 3.8%, P = 0.095). Patients who received secondary ESD had favorable outcomes without severe adverse events. During a mean follow-up period, no local recurrence occurred in patients who received secondary ESD.

CONCLUSION

Secondary ESD of residual or locally recurrent gastric tumors appears to be a feasible and curative treatment though it requires greater technical efficiency and longer procedure time.

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.

Feasibility of Autologous Fibrin Glue and Polyglycolic Acid Sheets to Prevent Delayed Bleeding after Endoscopic Submucosal Dissection of Gastric Neoplasms in Patients Receiving Antithrombotic Therapy

Background/Aims

Delayed bleeding is one of the most serious complications following gastric endoscopic submucosal dissection (ESD) under antithrombotic therapy. As a safety measure, for patients receiving antithrombotic therapy, we covered the ESD ulcer with autologous fibrin glue (prepared using autologous blood) alone or with polyglycolic acid (PGA) sheets.

Methods

From July 2014 to November 2015, 20 patients with gastric neoplasms who were receiving antithrombotic therapy were enrolled in this study. After ESD, the ESD ulcers were covered with autologous fibrin glue alone or with PGA sheets. We prospectively evaluated the feasibility of this safety measure.

Results

In total, 22 lesions in 20 patients were resected en bloc by ESD. The mean specimen size and tumor size were 31.5 ± 9.5 mm and 14.0 ± 8.8 mm, respectively. There were no cases of delayed bleeding or adverse events in this study. Attachment of autologous fibrin glue was observed in 81.8% (18/22) and 68.2% (15/22) of lesions at endoscopy performed 1 day and 7 days after ESD, respectively.

Conclusion

No patient in this study had delayed bleeding or adverse events. This suggests that this measure may facilitate the safety of gastric ESD in patients receiving antithrombotic therapy. This trial is registered with UMIN000019386.

Long-Term Clinical Efficacy and Perioperative Safety of Endoscopic Submucosal Dissection versus Endoscopic Mucosal Resection for Early Gastric Cancer: An Updated Meta-Analysis

BACKGROUND

To systematically evaluate the safety and efficacy of endoscopic submucosal dissection (ESD) versus endoscopic mucosal resection (EMR) for early gastric cancer (EGC).

METHODS

We searched the databases of PubMed, Web of Science, EMBASE, and the Cochrane Library from January 2000 to April 2017 and included studies that compared the outcomes of ESD with EMR for EGC. These eligible studies that met the inclusion criteria were screened out and were assessed by two independent investigators.

RESULT

In total, 18 retrospective cohort studies were eligible for analysis. Our results indicated that ESD is more beneficial than EMR in increasing the complete resection rate and en bloc resection rate and decreasing the local recurrence rate. However, ESD prolonged operative time and increased incidence of gastric perforation than EMR. No differences were found in postoperative bleeding rate between the two approaches.

CONCLUSION

Compared with EMR, ESD offers higher complete resection rate, higher en bloc resection rate, and lower local recurrence rate but has prolonged operative time and increased incidence of gastric perfusion. There is no statistical difference in the rate of postoperative bleeding between the two groups. However, the above conclusion needs further verification by well-designed, randomized trials with larger samples and long follow-up periods.

The feasibility of colorectal endoscopic submucosal dissection for the treatment of residual or recurrent tumor localized in therapeutic scar tissue

BACKGROUND AND STUDY AIMS

 Endoscopic submucosal dissection (ESD) is used to treat superficial colorectal tumors. Previous studies have reported the efficacy of ESD for treating residual or local recurrent colorectal tumors. This study sought to evaluate the efficacy of ESD in treating these lesions and to assess factors that prevent successful ESD.

METHODS

 This retrospective study assessed 25 cases of residual or local recurrent lesions that were previously treated using EMR (18 lesions), TEM (5 lesions), ESD (1 lesion) or surgery (1 lesion), and 459 primary lesions treated using ESD between April 2008 and September 2015. Clinicopathological characteristics, treatment outcome and adverse events were compared between groups with or without scar tissue. Factors related to perforation and a prolonged treatment time, which indicate the likelihood of technical difficulties, were identified using multiple logistic regression analysis.

RESULTS

In residual or local recurrent lesions groups, patients experienced more perforations (32 % vs 4 %, P  < 0.001) and required a longer treatment time (117 min vs 61 min, P  < 0.001) compared with the primary lesions group. Both groups showed a similar curative resection rate. Emergency surgery was not needed in any case. Multiple logistic regression analysis indicated that tumor location and therapeutic scar tissue were high risk factors for perforation, and that large tumor size and therapeutic scar tissue were high risk factors for prolonged treatment time.

CONCLUSIONS

ESD for residual or local recurrent colorectal tumors is a technically challenging, but effective and minimally invasive treatment. When performed carefully with sufficient proficiency, it is a useful treatment option.

Vascular density of superficial esophageal squamous cell carcinoma determined by direct observation of resected specimen using narrow band imaging with magnifying endoscopy

Observation of the microvasculature using narrow band imaging (NBI) with magnifying endoscopy is useful for diagnosing superficial squamous cell carcinoma. Increased vascular density is indicative of cancer, but not many studies have reported differences between cancerous and noncancerous areas based on an objective comparison. We observed specimens of endoscopic submucosal dissection (ESD) using NBI magnification, and determined the vascular density of cancerous and noncancerous areas. A total of 25 lesions of esophageal squamous cell carcinoma that were dissected en bloc by ESD between July 2013 and December 2013 were subjected to NBI magnification. We constructed a device that holds an endoscope and precisely controls the movement along the vertical axis in order to observe submerged specimens by NBI magnification. NBI image files of both cancerous (pathologically determined invasion depth, m1/2) and surrounding noncancerous areas were created and subjected to vascular density assessment by two endoscopists who were blinded to clinical information. The invasion depth was m1/2 in 20, m3/sm1 in four and sm2 in one esophageal cancer lesion. Mean vascular density was significantly increased in cancerous areas (37.6 ± 16.3 vessels/mm2) compared with noncancerous areas (17.6 ± 10.0 vessels/mm2) (P < 0.05). The correlation coefficients between vascular density determined by two endoscopists were 0.86 and 0.81 in cancerous and noncancerous areas, respectively. Receiver operating curve (ROC) analysis revealed that the area under the curve (AUC) of vascular density was 0.895 (95% CI, 0.804-0.986). For this ROC curve, sensitivity was 78.3% and specificity was 87.0% when the cutoff value of vascular density was 26 vessels/mm2. NBI magnification confirmed significant increases in vascular density in cancerous areas compared with noncancerous areas in esophageal squamous cell carcinoma. The rates of agreement between vascular density values determined by two independent operators were high.

Short-Term Outcomes of Endoscopic Submucosal Dissection in Patients with Early Gastric Cancer: A Prospective Multicenter Cohort Study

BACKGROUND/AIMS

Endoscopic submucosal dissection (ESD) is an effective treatment for early gastric cancer (EGC) that has demonstrated a minimal risk of lymph node metastasis in retrospective studies. We sought to prospectively evaluate the short-term outcomes of ESD treatment in EGCs.

METHODS

A prospective multicenter cohort study of neoplasms 3 cm or less in diameter at endoscopic size evaluation was performed in 12 Korean ESD study grouprelated university hospitals and the National Cancer Center. Resected specimens were evaluated by the central pathologic review board.

RESULTS

A patient cohort (n=712) with a total of 737 EGCs was analyzed. The margin-free en bloc resection rate was 97.3%, and curative resection of 640 lesions (86.8%) was achieved. Lower curative resection rates were associated with lesions 2 to 3 cm in size prior to ESD compared with lesions 2 cm or less in size (78.6% vs 88.1%, respectively, p=0.009). Significant factors associated with noncurative resection were moderately or poorly differentiated histological type, posterior wall tumor location, tumor size larger than 3 cm, ulceration, and submucosal invasion. Delayed bleeding occurred in 49 patients (6.9%), and 12 patients (1.7%) exhibited perforations.

CONCLUSIONS

ESD is an effective treatment with a high curative resection rate for EGCs that meets relatively conservative pre-ESD indications. Long-term survival outcomes should be evaluated in followup studies.

Clinical outcomes of early gastric cancer patients after noncurative endoscopic submucosal dissection in a large consecutive patient series

BACKGROUND

Clinical outcomes of early gastric cancer (EGC) patients after noncurative endoscopic submucosal dissection (ESD) have not been fully elucidated; we therefore aimed to clarify these outcomes.

METHODS

A total of 3058 consecutive patients with 3474 clinically diagnosed EGCs at initial onset underwent ESD with curative intent at our hospital between 1999 and 2010. We retrospectively assessed the following clinical outcomes of noncurative gastric ESD patients with a possible risk of lymph node (LN) metastasis by dividing patients into two groups with different treatment strategies (additional gastrectomy and simple follow-up): presence of LN metastasis at the time of gastrectomy, incidence of LN and distant metastases during the follow-up period, clinicopathological factors associated with metastasis, and 5-year disease-specific survival (DSS).

RESULTS

After exclusion of 75 noncurative ESD patients with only a positive horizontal margin, 569 noncurative ESD patients with a possible risk of LN metastasis were identified. Among the 356 patients undergoing additional gastrectomy, LN metastasis was identified in 18 patients. A positive vertical margin with submucosal invasion (odds ratio 3.6) and lymphovascular invasion (odds ratio 3.5) were significantly associated with LN metastasis. The 5-year DSS rate was 98.8 %. Among the 212 patients who underwent simple follow-up, LN and/or distant metastases were found in eight patients. In this group, lymphovascular invasion (hazard ratio 6.6) was significantly associated with metastasis with a 5-year DSS rate of 96.8 %.

CONCLUSIONS

Additional gastrectomy should be performed particularly in noncurative gastric ESD patients with lymphovascular invasion or a positive vertical margin with submucosal invasion.

Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Non-Ampullary Superficial Duodenal Tumor

BACKGROUND

Endoscopic submucosal resection (ESD) and endoscopic mucosal resection (EMR) are well established as curable and safety procedures for treating superficial tumors of the stomach, esophagus and colon. However, a majority of endoscopic resection strategies for non-ampullary superficial duodenal tumors (NASDTs) remains undefined. The aim of this study was to clarify which was the right method for NASDT treatment - EMR or ESD.

SUMMARY

We analyzed 129 consecutive endoscopic resection (74 ESD and 55 EMR) procedures performed with NADSTs and divided the ESD group into 49 large ESD groups (more than 20 mm in diameter) and 25 small ESD groups (less than 20 mm in diameter). With respect to the technical outcomes of EMR/ESD for small size NASDTs, EMR was safer than ESD, but its nature of curability was inferior to that of ESD. The rates of complication such as perforation or delayed bleeding were significantly higher in both ESD groups than in the EMR group. However, the prophylactic endoscopic closure of large mucosal defects after ESD was useful for resolving those complications. The limitations of our study were involvement of a single-center, limited sample size, short follow-up duration and the retrospective design, which may have introduced selection bias. However, the present findings suggest that adequate endoscopic treatment strategy for NASDTs can lead to favorable outcomes and an excellent prognosis. Key Message: It is necessary to select EMR or ESD adequately for R0 resection of small NASDTs, according to their size and location. For large NASDTs, duodenal ESD with essential management is feasible and useful as a therapeutic procedure.

Postoperative bleeding after gastric endoscopic submucosal dissection in patients receiving antithrombotic therapy

BACKGROUND AND AIMS

It is controversial whether antithrombotic therapy increases the risk of bleeding after endoscopic submucosal dissection (ESD). The aim of this study was to evaluate the effects of antithrombotic therapy on gastric ESD.

METHODS

Patients who underwent gastric ESD at Toranomon Hospital between April 2005 and July 2014 were enrolled. The risk of post-ESD bleeding was evaluated by multivariate logistic regression analysis.

RESULTS

Of 1781 patients enrolled, 253 were taking an antithrombotic; 186 discontinued taking a single antithrombotic (n = 150) or multiple antithrombotics (n = 36) before ESD, whereas 15 continued taking a single antiplatelet agent and another 52 switched to heparin alternative therapy during the peri-ESD period. Post-ESD bleeding occurred in 101 patients (5.7 %): 68 patients (3.8 %) who did not take an antithrombotic, 11 patients (7.3 %) who discontinued taking a single antithrombotic, six patients (16.7 %) who discontinued taking multiple antithrombotics, one patient (6.7 %) who continued taking a single antiplatelet agent, and 15 patients (28.8 %) who switched to heparin therapy. In multivariate analysis, heparin alternative therapy [odds ratio (OR) 10.04, 95 % confidence interval (CI) 4.35-23.16], discontinuation of the use of multiple antithrombotics before ESD (OR 5.44, 95 % CI 2.00-14.79), tumor location in the lower third of the stomach (OR 2.17, 95 % CI: 1.32-3.58), and a long procedure time (100 min or greater; OR 2.00, 95 % CI 1.25-3.20) were independent risk factors for post-ESD bleeding. Among 52 subjects who switched to heparin therapy, one developed acute renal infarction and one developed cerebral bleeding.

CONCLUSIONS

Because heparin alternative therapy significantly increases the risk of post-ESD bleeding and may not decrease the risk of thromboembolic events, other options should be considered for patients receiving anticoagulation therapy.

Early Gastric Cancer: Current Advances of Endoscopic Diagnosis and Treatment

Endoscopy is a major method for early gastric cancer screening because of its high detection rate, but its diagnostic accuracy depends heavily on the availability of endoscopic instruments. Many novel endoscopic techniques have been shown to increase the diagnostic yield of early gastric cancer. With the improved detection rate of EGC, the endoscopic treatment has become widespread due to advances in the instruments available and endoscopist's experience. The aim of this review is to summarize frequently-used endoscopic diagnosis and treatment in early gastric cancer (EGC).

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society (JGES), in collaboration with the Japanese Gastric Cancer Association (JGCA), has produced 'Guidelines for ESD and EMR for Early Gastric Cancer', as a set of basic guidelines in accordance with the principles of evidence-based medicine. These Guidelines cover the present state of knowledge and are divided into the following seven categories: Indications, Preoperative diagnosis, Techniques, Evaluation of curability, Complications, Long-term postoperative surveillance, and Histology. Twenty-three statements were finally accepted as guidelines, and the majority of these were obtained from descriptive studies with lower evidence levels. A number of statements had to be created by consensus (the lowest evidence level), as evidence levels remain low for many specific areas in this field.

Endoscopic Submucosal Dissection for Gastrointestinal Superficial Lesions: Initial Experience in a Single Portuguese Center

INTRODUCTION

Endoscopic submucosal dissection (ESD) is a minimally invasive organ-sparing endoscopic technique which allows en bloc resection of premalignant and early malignant lesions of the gastrointestinal tract regardless of size. In spite of the promising results, mainly from Japanese series, ESD is still not being widely used in western countries. This study aims to report the feasibility, safety and effectiveness of ESD technique for treating premalignant and early malignant gastrointestinal (GI) lesions (esophagus, gastric and rectum) in a Portuguese center.

PATIENT AND METHODS

From December 2011 to November 2014, 34 GI lesions were treated by ESD. The location, en bloc and pathological complete resection (R0) rates, procedure time, complications and local recurrence were retrospectively evaluated.

RESULTS

From 34 resected lesions, 18 were gastric (GL), 15 were rectal (RL) and one esophageal (EL). En bloc resection for each location was 17/18 (94%), 11/15 (73%) and 1/1 respectively. R0 was achieved in 16/18 (89%) GL, 9/15 (60%) RL and 1/1 EL. Mean resection time was 67 min for GL, 142 min for RL and 40 min for EL. Complications included immediate (6%) and delayed (3%) minor bleeding but no perforation. One local residual lesion from a RL was reported in the follow-up, effectively treated with an endoscopic technique. Disease-specific survival was 100% over a mean follow-up period of 14 months.

CONCLUSION

ESD has shown to be a safe and feasible resection method, achieving high R0, low recurrence and complication rates. Our results are similar to those reported in other international series.

Delayed bleeding after endoscopic submucosal dissection for non-ampullary superficial duodenal neoplasias might be prevented by prophylactic endoscopic closure: analysis of risk factors

BACKGROUND AND AIM

Duodenal endoscopic submucosal dissection (ESD) is technically challenging because of anatomical specificities and, to date, has not been validated concerning the high rate of complications such as perforation and delayed bleeding. In the present study, the risk factors for delayed bleeding after duodenal ESD are presented with the goal of establishing preventive measures.

METHODS

We analyzed 63 patients with non-ampullary superficial duodenal neoplasias treated by ESD from April 2005 to March 2014. To analyze the risk factors of delayed bleeding after duodenal ESD, we divided the patients into a delayed bleeding group and a non-bleeding group. To verify the risk factors of delayed bleeding after duodenal ESD, we analyzed various patient-, lesion-, and treatment-related factors.

RESULTS

Delayed bleeding was experienced in 11 patients (17.5%) Univariate analysis of patient-related risk factors of delayed bleeding indicated no significant risk factor. Univariate analysis of lesion-related and treatment-related risk factors indicated only endoscopic closure as a significant risk factor. Multivariate analysis also identified endoscopic closure (not done > done: P = 0.049) as an independent factor significantly associated with delayed bleeding after duodenal ESD. Hypertension (present > absent: P = 0.055) showed a non-significant tendency of association by multivariate analysis.

CONCLUSIONS

This retrospective evaluation found that endoscopic closure was associated with a reduced risk of delayed bleeding after duodenal ESD. Delayed bleeding after duodenal ESD might be prevented by prophylactic endoscopic closure.

Secondary endoscopic submucosal dissection for residual or recurrent tumors after gastric endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) is a widely accepted technique for the management of gastric tumors. However, residual or recurrent tumors can occur after ESD; currently, there is no adequate management strategy for these tumors. Thus, the aim of the present study was to establish a strategy of secondary ESD (sESD) for cases with positive lateral margins (LM+), which cause post-ESD residual or recurrent tumors.

METHODS

Fifty-three lesions that were subjected to ESD were diagnosed as LM+ with suspected local residual tumor. The short- and long-term outcomes of early sESD (performed shortly after the initial ESD in LM+ cases to prevent local recurrence) were retrospectively compared with those of late sESD (performed after the detection of recurrent tumors).

RESULTS

Of the 53 LM+ cases, the local residual positive rate was 38.5 % (10/26) in those undergoing early sESD or additional surgery and the local recurrence rate was 29.6 % (8/27) in those that were not treated. Thus, the overall incidence of residual or recurrent tumors in LM+ cases was 34.0 % (18/53). Both early and late sESD had favorable outcomes with no severe complications: 100 % of early sESD resections were curative, compared with 86.7 % of late sESD resections, over the course of a mean (±SD) observation period of 50.8 ± 16.7 months. The performance of early sESD was significantly greater than that of late sESD (in terms of dissection speed).

CONCLUSIONS

Early sESD is more reliable than late sESD as a therapeutic strategy for salvaging residual tumors and for preventing recurrence. However, if a tumor has already recurred, late sESD remains useful.

Endoscopic submucosal dissection for nonampullary large superficial adenocarcinoma/adenoma of the duodenum: feasibility and long-term outcomes

BACKGROUND AND STUDY AIMS

The clinical benefit of endoscopic submucosal dissection (ESD) for superficial duodenal neoplasias has not yet been verified. The aims of this study were to validate the feasibility and long-term outcomes of ESD for nonampullary superficial duodenal neoplasias, larger than 20 mm.

PATIENTS AND METHODS

41 patients, with 41 nonampullary large superficial duodenal neoplasias, who underwent ESD between April 2005 to March 2013 were included in the study. The short- and long-term outcomes were retrospectively evaluated, related to tumor size, resection size, histological type, invasion depth, complete resection rate, operation time, perforation rate, delayed bleeding rate, local recurrence rate, distant metastasis, and survival rate.

RESULTS

ESD was successfully completed in 38 of 41 patients (92.7 %). The median sizes of tumors and resected specimens were, respectively, 26 mm (range 20 - 70 mm) and 36.5 mm (range 23 - 80 mm). Histopathological findings showed 13 adenocarcinomas (12 mucosal, 1 submucosal) and 28 adenomas (26 high grade dysplasia, 2 low grade dysplasia). The complete resection rate was 89.5 % (34 /38 tumors). The mean operation time was 128.3minutes. Perforation during ESD occurred in 39 % and delayed bleeding occurred in 18.4 %. The median observation period was 48 months (range 3.2 - 94.1 months), and no local recurrence or distant metastasis was seen during this time, representing a disease-free survival rate of 100 %.

CONCLUSIONS

ESD for nonampullary large superficial duodenal adenocarcinoma/adenoma is feasible with favorable long-term outcomes. However, because of the high complication rate due to its technical difficulty, experience and skill of the operator, along with adequate perioperative management, are essential.

Prospective Study about the Utility of Endoscopic Ultrasound for Predicting the Safety of Endoscopic Submucosal Dissection in Early Gastric Cancer (T-HOPE 0801)

Background. Intraoperative bleeding is an important determinant for safety of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study aimed to prospectively evaluate the usefulness of endoscopic ultrasound (EUS) for predicting ESD safety. Methods. A total of 110 patients with EGC were divided into two groups based on EUS findings: group P, almost no blood vessels in submucosa, or ≤4 small vessels per field of view; group R, remaining patients. Primary endpoint was the decrease in Hb after ESD. Secondary endpoints included procedure time and the incidence of muscle injury and clip use. Results. A total of 89 patients were evaluated. Fifty were classified into group P and 39 into group R. Mean decrease in Hb was 0.27 g/dL in group P and 0.35 g/dL in group R, with no significant difference. Mean procedure time was significantly longer in group R (105.4 min) than in group P (65.5 min) (P < 0.001). The incidence of muscle injury and clip use were significantly higher in group R (25.6%/48.7%) than in group P (8.0%/20.0%) (P = 0.02/P = 0.004). Conclusion. Preoperative EUS can predict procedure time and the incidence of muscle injury and clip use and is thus considered useful for predicting gastric ESD safety.

Tissue engineering of the stomach

Tissue engineering combines engineering principles with the biological sciences to create functional replacement tissues. The underlying principle of tissue engineering is that isolated cells combined with biomaterials can form new tissues and organs in vitro and in vivo. This review focuses on stomach tissue engineering, which is a promising approach to the treatment of gastric cancer, the fourth most common malignancy in the world and the second-leading cause of cancer mortality worldwide. Although gastrectomy is a reliable intervention to achieve complete removal of cancer lesions, the limited capacity for food intake after resection results in lower quality of life for patients. To address this issue, we have developed a tissue-engineered stomach to increase the capacity for food intake by creating a new food reservoir. We have transplanted this neo-stomach as a substitute for the original native stomach in a rat model and confirmed functional adaptation. Furthermore, we have demonstrated the feasibility of transplanting a tissue-engineered gastric wall patch in a rat model to alleviate the complications after resection of a large area of the gastric wall. Although progress has been achieved, significant challenges remain to bring this approach to clinical practice. Here, we summarize our work and present the state of the art in stomach tissue engineering.

Complications of gastric endoscopic submucosal dissection

Endoscopic resection is now a widely accepted treatment for early gastric cancer, having a negligible risk of lymph-node metastasis. Endoscopic submucosal dissection (ESD) is a relatively new endoscopic resection method developed in the mid-1990 s that facilitates en-bloc resection even in patients with large or ulcerative lesions difficult to resect using conventional endoscopic mucosal resection (EMR). However, compared to EMR, ESD requires a longer procedure time and a higher level of technical expertise, in addition to having a slightly greater risk of complications. Endoscopists must be aware of not only the risk factors for, and incidence of, complications, but also how to effectively treat such complications. Perforation and bleeding are the major complications associated with gastric ESD. The perforation and delayed bleeding rates have been reported to range from 1.2% to 5.2% and 0% to 15.6%, respectively, and can usually be managed with appropriate endoscopic treatment. Immediate bleeding during gastric ESD is quite common and controlling such bleeding, which is primarily achieved by carrying out electrocautery, plays a critical role in the successful completion of ESD.

Usefulness of magnifying endoscopy with narrow-band imaging for determining tumor invasion depth in early gastric cancer

Backgrounds. Magnifying endoscopy with narrow-band imaging (ME-NBI) has become essential for determining tumor margin in early gastric cancer (EGC). Here, we investigated the usefulness of ME-NBI for assessment of invasion depth in EGC. Methods. For 119 patients who had undergone ME-NBI and en bloc resection by endoscopic submucosal dissection, three physicians prospectively examined high-magnification ME-NBI images for clinical features such as presence or absence of dilated vessels (D vessels). Cases with D vessels verified by at least two physicians were assigned to group V, and others were assigned to group N. We then compared clinicopathological factors associated with the groups. Results. Groups V and N consisted of 18 and 101 patients, respectively. There were no significant differences in age, gender, tumor size, tumor location, gross morphology, or histological type. The percentage of submucosal cancer was 9.9% (10/101) in group N and significantly higher at 33.3% (6/18) in group V (P = 0.007). When the presence of D vessels was considered a diagnostic criterion for submucosal cancer, diagnostic accuracy, sensitivity, and specificity were 81.5, 37.5, and 88.3%, respectively. Conclusions. The results suggest that identification of D vessels using ME-NBI can assist in the assessment of invasion depth in EGC.

Endoscopic submucosal dissection and surgical treatment for gastrointestinal cancer

Endoscopic submucosal dissection (ESD) is widely used in Japan as a minimally invasive treatment for early gastric cancer. The application of ESD has expanded to the esophagus and colorectum. The indication criteria for endoscopic resection (ER) are established for each organ in Japan. Additional treatment, including surgery with lymph node dissection, is recommended when pathological examinations of resected specimens do not meet the criteria. Repeat ER for locally recurrent gastrointestinal tumors may be difficult because of submucosal fibrosis, and surgical resection is required in these cases. However, ESD enables complete resection in 82%-100% of locally recurrent tumors. Transanal endoscopic microsurgery (TEM) is a well-developed surgical procedure for the local excision of rectal tumors. ESD may be superior to TEM alone for superficial rectal tumors. Perforation is a major complication of ESD, and it is traditionally treated using salvage laparotomy. However, immediate endoscopic closure followed by adequate intensive treatment may avoid the need for surgical treatment for perforations that occur during ESD. A second primary tumor in the remnant stomach after gastrectomy or a tumor in the reconstructed organ after esophageal resection has traditionally required surgical treatment because of the technical difficulty of ER. However, ESD enables complete resection in 74%-92% of these lesions. Trials of a combination of ESD and laparoscopic surgery for the resection of gastric submucosal tumors or the performance of sentinel lymph node biopsy after ESD have been reported, but the latter procedure requires a careful evaluation of its clinical feasibility.

A meta-analysis of endoscopic submucosal dissection and EMR for early gastric cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) was developed to overcome the problem caused by incomplete resection by conventional EMR for early gastric cancer. However, the technique of ESD had a relative higher incidence rate of complications such as bleeding and perforation because of its large wound incidence and difficulties.

OBJECTIVE

To evaluate the efficacy and safety of ESD and EMR for early gastric cancer.

DESIGN

We made an overall strategy to search various databases both electronically and manually and assessed the quality of selected articles according to the inclusion and exclusion standard.

SETTING

Meta-analysis of 9 retrospective studies.

PATIENTS

3548 lesions (ESD 1495; EMR 2053).

INTERVENTION

ESD or EMR.

MAIN OUTCOME MEASUREMENTS

En bloc resection rate, histologic curative resection rate, complications, recurrence rate.

RESULTS

Nine retrospective studies were identified (7 full text and 2 abstracts). A total of 3548 lesions were enrolled (ESD 1495; EMR 2053). The mean time required for resection was longer for ESD than for EMR (weighted mean difference 59.4; 95% confidence interval [CI], 16.8-102.0); the en bloc rate in the ESD group was significantly higher than that in the EMR group (OR 9.69; 95% CI, 7.74-12.13), and so was the total histologically complete resection rate (OR 5.66; 95% CI, 2.92-10.96). The ESD group had lower recurrence frequency (OR 0.10; 95% CI, 0.06-0.18). The perforation rate was higher in the ESD group (OR 4.67; 95% CI, 2.77-7.87), whereas the bleeding incidences were similar between the two groups.

LIMITATIONS

Heterogeneity was present among the studies.

CONCLUSION

Compared with EMR for early gastric cancer, ESD showed considerable advantages regarding en bloc resection rate, histologically complete resection rate, and local recurrence even for small lesions, but it had the disadvantages of higher complication rates for perforation. All of the results mentioned should be confirmed by well-designed, randomized, controlled trials from more countries, with larger samples and long enough follow-up periods.

Prospective randomized controlled trial to compare the effects of omeprazole and famotidine in preventing delayed bleeding and promoting ulcer healing after endoscopic submucosal dissection

BACKGROUND AND AIMS

Proton pump inhibitors (PPIs) are generally used to prevent delayed bleeding after endoscopic submucosal dissection (ESD) and to heal the artificial ulcers. However, it remains controversial whether PPIs or histamine-2 receptor antagonists (H(2) RAs) are more effective in preventing delayed bleeding after ESD. We prospectively compared the effects of omeprazole and famotidine in preventing delayed bleeding and promoting artificial ulcer healing after ESD.

METHODS

A total of 158 patients (155 early gastric cancers and three adenomas) were randomly assigned to the PPI group (omeprazole 20 mg/day) or H(2) RA group (famotidine 40 mg/day) in a prospective randomized controlled trial. The primary end point was the incidence of hematemesis, melena, and/or a decrease in hemoglobin level of 2 g/dL or more requiring endoscopic hemostatic treatment. ESD-induced ulcer healing and changes in ulcer size were also compared at 6 weeks after ESD as a secondary end point.

RESULTS

Of the 158 patients, two were excluded from analysis because they had been treated with a PPI before the present study. Accordingly, data from 77 PPI and 79 H(2) RA subjects were included for analysis. Delayed bleeding after ESD occurred in 6.5% of subjects (PPI group) and in 6.3% (H(2) RA group); there was no significant difference between the two groups. Likewise, the two groups were not significantly different with respect to ulcer stage or ulcer size reduction rate.

CONCLUSIONS

Proton pump inhibitors are not superior to H(2) RAs for the prevention of delayed bleeding or the healing of artificially induced ulcers after ESD.

A technical review of flexible endoscopic multitasking platforms

BACKGROUND

Further development of advanced therapeutic endoscopic techniques and natural orifice translumenal endoscopic surgery (NOTES) requires a powerful flexible endoscopic multitasking platform.

METHODS

Medline search was performed to identify literature relating to flexible endoscopic multitasking platform from year 2004-2011 using keywords: Flexible endoscopic multitasking platform, NOTES, Instrumentation, Endoscopic robotic surgery, and specific names of various endoscopic multitasking platforms. Key articles from articles references were reviewed.

RESULTS

Flexible multitasking platforms can be classified as either mechanical or robotic. Purely mechanical systems include the dual channel endoscope (DCE) (Olympus), R-Scope (Olympus), the EndoSamurai (Olympus), the ANUBIScope (Karl-Storz), Incisionless Operating Platform (IOP) (USGI), and DDES system (Boston Scientific). Robotic systems include the MASTER system (Nanyang University, Singapore) and the Viacath (Hansen Medical). The DCE, the R-Scope, the EndoSamurai and the ANUBIScope have integrated visual function and instrument manipulation function. The IOP and DDES systems rely on the conventional flexible endoscope for visualization, and instrument manipulation is integrated through the use of a flexible, often lockable, multichannel access device. The advantage of the access device concept is that it allows optics and instrument dissociation. Due to the anatomical constrains of the pharynx, systems are designed to have a diameter of less than 20 mm. All systems are controlled by traction cable system actuated either by hand or by robotic machinery. In a flexible system, this method of actuation inevitably leads to significant hysteresis. This problem will be accentuated with a long endoscope such as that required in performing colonic procedures. Systems often require multiple operators. To date, the DCE, the R-Scope, the IOP, and the Viacath system have data published relating to their application in human.

CONCLUSION

Alternative forms of instrument actuation, camera control and master console ergonomics should be explored to improve instrument precision, sphere of action, size and minimize assistance required.

Learning curve for endoscopic submucosal dissection of early gastric cancer based on trainee experience

BACKGROUND AND AIM

There have been few previous reports on endoscopic submucosal dissection (ESD) learning curve for early gastric cancer (EGC) so we retrospectively assessed this subject based on experience of our trainees.

METHODS

Trainees in our center start performing ESDs for lesions in lower third of stomach with hands-on support by experts during first 10 cases and then perform ESDs by themselves primarily with verbal guidance from experts. They are gradually assigned to perform ESDs in middle and upper thirds of stomach. From January 1999 to December 2008, 464 EGC patients, who underwent ESD performed by 13 trainees, were assessed by dividing ESD cases into five training periods (A, 1-10; B, 11-20; C, 21-30; D, 31-40; and E, 41-50). We compared data from B to C, D and E.

RESULTS

Lesions in lower third were A/59%, B/57%, C/55%, D/36% and E/40% with B significantly higher than D (p<0.01) and E (p<0.05). Mean tumor sizes were A/13.9 ± 7.5mm, B/18.3 ± 11.4mm, C/19.0 ± 12.5mm, D/19.3 ± 11.7 mm and E/16.8 ± 10.3mm. En-bloc resection rate was 100% in every period. Delayed bleeding / perforation rates were A/0%/1.8%, B/2.8%/1.9%, C/1.9%/2.9%, D/1.1%/0% and E/2.1%/2.1%, respectively. Lower third procedure times were A/76 ± 39, B/90 ± 61, C/70 ± 48, D/60 ± 50 and E/55 ± 26 minutes with B significantly longer than D and E (p<0.05). Middle and upper third procedure times were A/104 ± 80, B/115 ± 68, C/106 ± 67, D/134 ± 86 and E/96 ± 55 minutes.

CONCLUSION

Step-by-step training was highly effective with 100% en-bloc resection rate and few complications. Learning curve point for our trainees to acquire performing ESD in lower third of stomach was 30 cases.

Management of bleeding and artificial gastric ulcers associated with endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD), an endoscopic procedure for the treatment of gastric epithelial neoplasia without lymph node metastases, spread rapidly, primarily in Japan, starting in the late 1990s. ESD enables en bloc resection of lesions that are difficult to resect using conventional endoscopic mucosal resection (EMR). However, in comparison to EMR, ESD requires a high level of endoscopic competence and a longer resection time. Thus, ESD is associated with a higher risk of adverse events, including intraoperative and postoperative bleeding and gastrointestinal perforation. In particular, because of a higher incidence of intraoperative bleeding with mucosal incision and submucosal dissection, which are distinctive endoscopic procedures in ESD, a strategy for endoscopic hemostasis, mainly by thermo-coagulation hemostasis using hemostatic forceps, is important. In addition, because of iatrogenic artificial ulcers that always form after ESD, endoscopic hemostasis and appropriate pharmacotherapy during the healing process are essential.

Proton Pump Inhibitor Therapy before and after Endoscopic Submucosal Dissection: A Review

Endoscopic submucosal dissection (ESD) is a novel endoscopic procedure first developed in the 1990s which enables en bloc resection of gastric neoplastic lesions that are difficult to resect via conventional endoscopic mucosal resection. However, given that ESD increases the risk of intra- and post-ESD delayed bleeding and that platelet aggregation and coagulation in artificial ulcers after ESD strongly depend on intragastric pH, faster and stronger acid inhibition via proton pump inhibitors (PPIs) and histamine 2-receptor antagonists (H(2)RAs) as well as endoscopic hemostasis by thermocoagulation during ESD have been used to prevent ESD-related bleeding. Because PPIs more potently inhibit acid secretion than H(2)RAs, they are often the first-line drugs employed in ESD treatment. However, acid inhibition after the initial infusion of a PPI is weaker in the early phase than that achievable with H(2)RAs; further, PPI effectiveness can vary depending on genetic differences in CYP2C19. Therefore, optimal acid inhibition may require tailored treatment based on CYP2C19 genotype when ESD is performed, with a concomitant infusion of PPI and H(2)RA possibly most effective for patients with the rapid metabolizer CYP2C19 genotype, while PPI alone may be sufficient for those with the intermediate or poor metabolizer genotypes.

Safety measures for gastrointestinal endoscopy in patients receiving antithrombotic therapy

AIM

Owing to carelessness of endoscopists, invasive procedures, such as biopsy, are sometimes carried out inadvertently in patients receiving antithrombotic therapy. The aim of the present study was to retrospectively evaluate the actual status of such careless mistakes and the efficacy of new safety measures.

METHODS

A questionnaire survey was conducted in 34 endoscopists at Toranomon Hospital about experiences of careless mistakes and experiences of anxiety before and after the procedure. 'Anxiety before procedure' was defined as the experience of discontinuing a given procedure because endoscopists remembered that the patient was receiving antithrombotic therapy, and 'anxiety after procedure' was defined as the experience of feeling anxious about the status of medication after the invasive procedure. A new measure was introduced at Health Management Center in August 2009. In this measure, endoscopists directly interview each patient about the status of medication just before examination, and attach forceps valves of one of two colors depending on the status of medication. A blue forceps valve is attached for patients undergoing antithrombotic therapy, and a conventional black forceps valve is attached for patients not undergoing antithrombotic therapy. Six months after introduction, a questionnaire survey was conducted in 10 endoscopists in this center.

RESULTS

Approximately half of endoscopists (18/34) experienced such careless mistakes. 'Anxiety' had been experienced by approximately 80%. After introduction, there was no report of careless mistakes and frequency of 'anxiety' evaluated by visual analog scale score decreased significantly.

CONCLUSION

This new safety measure is expected to facilitate safer gastrointestinal endoscopy in patients receiving antithrombotic therapy.

An update in endoscopic management of gastric cancer

PURPOSE OF REVIEW

Gastric cancer remains a prevalent disease with a 5-year mortality rate of less than 25%. This review focuses on the endoscopic detection, staging, and management of gastric adenocarcinoma.

RECENT FINDINGS

Confocal laser endomicroscopy and narrow band imaging have a 77-99.4% sensitivity for early cancer detection, a significant improvement when compared with white light endoscopy. Proper staging can be accomplished through endoscopic ultrasound and multidetector row-computed tomography, with accuracy as high as 90.1%. Endoscopic management of early gastric cancer is minimally invasive and can be preferable to surgery. In properly selected patients, endoscopic submucosal dissection has been found to have 100% 5-year survival.

SUMMARY

The recent advances in gastric cancer have greatly improved the care we can offer our patients in gastric oncology. The emerging technologies will hopefully continue to promote this trend.

The effectiveness and safety of endoscopic submucosal dissection compared with endoscopic mucosal resection for early gastric cancer: a systematic review and metaanalysis

BACKGROUND

Endoscopic submucosal dissection (ESD) allows en bloc resection of the entire lesion, permitting a higher curative resection rate and increased quality of life by minimizing the resection size compared with that of endoscopic mucosal resection (EMR). Although ESD has been implemented at most university hospitals in Korea, potential complications of ESD such as bleeding and perforation raise doubts in the therapeutic decision on use of the ESD procedure for early gastric cancer patients and in reimbursement decision making. This systematic review aimed to address both the effectiveness and safety outcomes of ESD versus EMR for early gastric cancer.

METHODS

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and Koreamed were searched using the primary keywords "stomach neoplasm" AND "endoscopic submucosal dissection" AND "endoscopic mucosal resection." To assess the quality of selected studies, the methodologic approach of the Scottish Intercollegiate Guidelines Network was used. Five effectiveness-relevant and three safety-relevant outcome measures were extracted. Bibliography management and metaanalysis for each outcome were conducted using Review Manager 5.0.

RESULTS

Three nonconcurrent cohort studies and nine retrospective cohort studies were identified. Metaanalyses showed ESD to be significantly more effective than EMR for en bloc resection (odds ratio [OR], 8.43; 95% confidence interval [CI], 5.20-13.67), complete resection (OR, 14.11; 95% CI, 10.85-18.35), curative resection (OR, 3.28; 95% CI, 1.95-5.54), and local recurrence (risk ratio [RR], 0.13; 95% CI, 0.04-0.41). Whereas intraoperative bleeding (RR, 2.16; 95% CI, 1.14-4.09), perforation risk (RR, 3.58; 95% CI, 1.95-6.55), and operation time (standard mean difference [SMD], 1.55; 95% CI, 0.74-2.37) were significantly greater for ESD, overall bleeding risk (RR, 1.22; 95% CI, 0.76-1.98) and all-cause mortality (RR, 0.65; 95% CI, 0.08-5.38) did not differ significantly between ESD and EMR.

CONCLUSIONS

Considering that bleeding risk did not differ significantly between ESD and EMR and that perforation risk usually does not lead to life-threatening disease, the effectiveness benefit of ESD can outweigh the overall harm compared with EMR on the condition that ESD is performed by experienced practitioners.

Endoscopic submucosal dissection for submucosal invasive gastric cancer and curability criteria

AIMS

The aims of the present study were to evaluate the feasibility of endoscopic submucosal dissection (ESD) as curative treatment for node-negative submucosal invasive early gastric cancer (EGC) and to consider further expansion of the curability criteria for submucosal invasive EGC.

METHODS

A total of 977 EGC in 855 patients treated by ESD were enrolled. They were divided into intramucosal cancer (M); minimally submucosal invasive cancer (<500µm from the muscularis mucosa) (SM1); and deeper submucosal invasive cancer (>500µm from the muscularis mucosa) (SM2). The technical feasibility of ESD for SM1 and M were compared, and the clinical prognosis of SM1 was evaluated. Furthermore, the volume of carcinoma invading to the submucosal layer, which we called the SM volume index, was calculated virtually to analyze its correlation with lymphatic-vascular invasion.

RESULTS

There were no statistical differences in technical outcomes and complications between M and SM1. Curative resection rates were significantly better in M than in SM1 (M, 92.6%; SM1, 63.8%). No local recurrences and distant metastases were found in 48 SM1 patients declared to have undergone curative resections. Most cases (72.0%) with successful ESD but non-curative resection exceeded 30mm in maximum size, and no local recurrences and metastases were found in these patients. The SM volume index of these cases was comparatively small.

CONCLUSION

The technical and theoretical validity of ESD for SM1 was validated. The possibility of further expansion of the curability criteria for submucosal invasive cancers was suggested by the evaluation of the SM volume index.

Endoscopic submucosal dissection for residual/locally recurrent lesions after endoscopic therapy for colorectal tumors

BACKGROUND AND STUDY AIM

Residual or locally recurrent lesions may occur after endoscopic therapy for epithelial colorectal tumors. Additional endoscopic mucosal resection is difficult for large lesions. Endoscopic submucosal dissection may be useful for such lesions, but may be more technically difficult for residual/locally recurrent lesions than for primary lesions. This study evaluated the efficacy of endoscopic submucosal dissection for residual/locally recurrent lesions in comparison with primary lesions.

METHOD

This retrospective case-control investigated 34 residual/locally recurrent lesions and 384 primary lesions treated using endoscopic submucosal dissection. Tumor size, resected specimen size, procedure duration, en bloc resection rate, curative resection rate, histology, associated complications, and recurrence rate were compared between groups.

RESULTS

Procedure duration tended to be longer (85 ± 53 min vs 73 ± 55 min) and tumors were significantly smaller (20 ± 13 mm vs 33 ± 20 mm; P < 0.001) in the residual/locally recurrent group, compared with primary lesions. Both groups showed similar percentages of en bloc (100% vs 97.4%) and curative resection (88.4% vs. 83.6%). Perforation rate was significantly higher in the residual/locally recurrent group (14.7% vs 4.4%, P < 0.05). However, emergency surgery was only needed in 1 of 5 cases in the residual/locally recurrent group, with the remaining 4 cases conservatively managed using endoclips.

CONCLUSIONS

Endoscopic submucosal dissection for residual/locally recurrent lesions was curative and efficacy. This procedure could help to avoid surgical resection and frequent follow-up examinations in many patients.

Fine-tuning the criteria for strip biopsy and endoscopic submucosal dissection improves the outcome of early gastric carcinoma treatment

BACKGROUND AND AIM

Strip biopsy and endoscopic submucosal dissection (ESD) have been developed as a local treatment for early gastric cancer (EGC). However, the lesion criteria for the use of ESD, rather than strip biopsy, remain to be elucidated.

METHODS

On the basis of reviews of literature and our observations concerning the outcome of strip biopsy, we set the criteria for selecting strip biopsy and ESD as follows. The indications for strip biopsy were lesions less than 10 mm in size and located in the anterior wall or greater curvature of the lower and middle stomach. ESD was indicated for all other lesions. The validity of the criteria was then analyzed prospectively in 156 patients. The rate of en bloc R0 resection and local recurrence were evaluated.

RESULTS

Subsequently, 156 lesions were divided according to the criteria and were endoscopically resected by strip biopsy (n = 13) or ESD (n = 143). The en bloc R0 resection rates for the whole group and the strip biopsy and ESD groups was 93.5% (146/156), 92.3% (12/13), and 93.7% (134/143), respectively. None of the patients had suffered from local recurrence in either the strip biopsy or ESD groups.

CONCLUSION

The validity of our criteria for selecting strip biopsy and ESD was verified. Our criteria exploit the advantages of both procedures and obtain better endoscopic therapy outcomes for EGC.