Pathological evaluation of gastrointestinal endoscopic submucosal dissection materials based on Japanese guidelines

Establishing and popularizing a standard pathological diagnostic model of endoscopic submucosal dissection specimens in China

BACKGROUND

Endoscopic submucosal dissection (ESD) is a standardized therapeutic approach for early carcinoma of the digestive tracts. In this regard, the process of histopathological diagnosis requires standardization. However, the uneven development of healthcare in China, especially in eastern and western China, creates challenges for sharing a standardized diagnostic process.

AIM

To optimize the process of ESD specimen sampling, embedding and slide production, and to provide complete and accurate pathological reports.

METHODS

We established a practical process of specimen sampling, created standardized reporting templates, and trained pathologists from neighboring hospitals and those in the western region. A training effectiveness survey was conducted, and the collected data were assessed by the corresponding percentages.

RESULTS

A total of 111 valid feedback forms have been received, among which 58% of the participants obtained photographs during specimen collection, whereas the percentage increased to 79% after training. Only 58% and 62% of the respondents ensured the mucosal tissue strips were flat and their order remained unchanged; after training, these two proportions increased to 95% and 92%, respectively. Approximately half the participants measured the depth of the submucosal infiltration, which significantly increased to 95% after training. The percentage of pathologists who did not evaluate lymphovascular invasion effectively reduced. Only 22% of the participants had fixed clinic-pathological meetings before training, which increased to 49% after training. The number of participants who had a thorough understanding of endoscopic diagnosis also significantly increased.

CONCLUSION

There have been significant improvements in the process of specimen collection, section quality, and pathology reporting in trained hospitals. Therefore, our study provides valuable insights for others facing similar challenges.

Optimizing duodenal tissue acquisition for mechanistic studies of duodenal ablation in type 2 diabetes

Background and study aims

Histological analysis of regular duodenal biopsies to study morphologic changes after duodenal ablation for type 2 diabetes (T2D) and metabolic syndrome is hampered by variability in tissue orientation. We designed an optimized tissue acquisition protocol using duodenal cold snare resections to create tissue microarrays (TMAs) and to allow for single-cell RNA sequencing (scRNA-seq).

Patients and methods

The open-label DIRECT study included patients undergoing an upper gastrointestinal interventional endoscopy for non-duodenal indications. All underwent one ot two single-piece duodenal cold snare resections. Endpoints were safety, adequate histological orientation of specimen and TMA, and tissue dissociation quality for scRNA-seq. The optimized tissue acquisition protocol was validated in a duodenal ablation study, EMINENT-2.

Results

In DIRECT, nine patients were included in whom a total of 16 cold snare resections were obtained. No severe adverse events (SAEs) occurred. Eighty percent of specimens and corresponding TMAs showed optimal tissue orientation. Further improvement was achieved by reducing tissue damage during endoscopic retrieval and improving histologic evaluation by eliminating ink use and pinning the tissue on cork. High-quality tissue dissociation scores for scRNA-seq were achieved in 13 of 18 samples (72%). In EMINENT-2, 38 cold snares were obtained without SAEs, histopathologic analysis showed good orientation in all samples, and dissociation scores for scRNA-seq were qualified in 35/38 (92%) samples.

Conclusions

Duodenal cold snare resection is safe and can provide high-quality tissue for optimally oriented TMAs and high-quality tissue dissociation scores for scRNA-seq (Clinicaltrials.gov, NCT06333093, NCT05984238). This approach will allow mechanistic studies about the effects of duodenal ablation on metabolic syndrome and T2D.

Comparison of two pathological processing methods for large endoscopic submucosal dissection (ESD) specimens

AIMS

Accurate histopathological evaluation of the endoscopic submucosal dissection (ESD) specimens is essential for clinicians to guide further triage and management. This study aimed to report a novel processing technique for large ESD (≥4 cm) specimens.

METHODS

92 patients with colorectal neoplasms who had undergone ESD were included. 46 ESD specimens were treated with conventional handling process, while the rest 46 cases were given the optimised method. Macrobiocassettes and L-shaped embedding moulds were applied in the optimised method. We evaluated the efficacy of this improved procedure in terms of the number of paraffin blocks, storage space and time consumption of pathological assessment.

RESULTS

The average diameter of ESD specimens was 4.5±0.4 cm and 4.7±0.5 cm in the control and test group (p=0.023), respectively. In control group, 398 paraffin blocks of 46 cases were obtained. With the same cases number and larger lesion size, only 276 blocks were achieved in test group (p<0.001). As for the storage space, the total volume of paraffin blocks and slides (4554.0 cm3 and 1207.5 cm3) of optimised method was significantly reduced compared with the control group (6208.8 cm3 and 1741.3 cm3) (p=0.001, p<0.001). In addition, the optimised method was superior to the conventional one in shortening time consumption of pathological assessment (164.5 min and 269.0 min, p<0.001).

CONCLUSIONS

The optimised technique not only reduced the workload and storage space, but also facilitated accurate pathological assessment.

Weakly Supervised Learning for Poorly Differentiated Adenocarcinoma Classification in GastricEndoscopic Submucosal Dissection Whole Slide Images

Objective: Endoscopic submucosal dissection (ESD) is the preferred technique for treating early gastric cancers including poorly differentiated adenocarcinoma without ulcerative findings. The histopathological classification of poorly differentiated adenocarcinoma including signet ring cell carcinoma is of pivotal importance for determining further optimum cancer treatment(s) and clinical outcomes. Because conventional diagnosis by pathologists using microscopes is time-consuming and limited in terms of human resources, it is very important to develop computer-aided techniques that can rapidly and accurately inspect large number of histopathological specimen whole-slide images (WSIs). Computational pathology applications which can assist pathologists in detecting and classifying gastric poorly differentiated adenocarcinoma from ESD WSIs would be of great benefit for routine histopathological diagnostic workflow. Methods: In this study, we trained the deep learning model to classify poorly differentiated adenocarcinoma in ESD WSIs by transfer and weakly supervised learning approaches. Results: We evaluated the model on ESD, endoscopic biopsy, and surgical specimen WSI test sets, achieving and ROC-AUC up to 0.975 in gastric ESD test sets for poorly differentiated adenocarcinoma. Conclusion: The deep learning model developed in this study demonstrates the high promising potential of deployment in a routine practical gastric ESD histopathological diagnostic workflow as a computer-aided diagnosis system.

Measuring the Submucosal Depth of Invasion in Endoscopic Mucosal Resections for Barrett-associated Adenocarcinoma: Practical Issues and Relevance for the Decision for Esophagectomy

CONTEXT.—

Endoscopic mucosal resection (EMR) has made it possible for Barrett esophagus patients with superficial cancers to be treated without esophagectomy. Recent guidelines recommend measuring depth of invasion (DOI) in submucosal cancers based on reports that in low-risk cancers, submucosal invasion 500 μm or less is associated with low nodal metastasis rates. However, pathologists face challenges in reproducibly measuring DOI.

OBJECTIVE.—

To determine how often DOI measurements could impact treatment and to evaluate reproducibility in measuring submucosal DOI in EMR specimens.

DESIGN.—

Consecutive adenocarcinoma EMR cases were identified, including cases of "low histologic risk" submucosal cancer, as follows: those with negative deep margins, no high-grade histology (G3), and no lymphovascular invasion. Submucosal DOI was measured by 7 pathologists according to guidelines.

RESULTS.—

Of 213 cancer EMR cases, 46 were submucosa invasive and 6 cases were low histologic risk submucosal cancers for which measurement could impact decision-making. Of these low histologic risk cases, 3 were categorized as superficial, indicating that measurement would be a clinically actionable decision point in only 1.4% of adenocarcinoma EMRs. Interobserver agreement for in-depth categorization between 7 pathologists was moderate (κ = 0.42), and the range of measurements spanned the 500-μm relevant threshold in 40 of 55 measured samples (72.7%).

CONCLUSIONS.—

While therapeutic decisions would rarely have depended on DOI measurements alone in our cohort, interobserver variability raises concerns about their use as a sole factor on which to offer patients conservative therapy. Responsibly reporting and clinically using submucosal DOI measurements will require practical experience troubleshooting common histologic artifacts, as well as multidisciplinary awareness of the impact of variable specimen-handling practices.

Artificial Intelligence Assisted Topographic Mapping System for Endoscopic Submucosal Dissection Specimens

Background

Endoscopic submucosal dissection (ESD), a minimally invasive surgery used to treat early gastrointestinal malignancies, has been widely embraced around the world. The gross reconstruction of ESD specimens can facilitate a more precise pathological diagnosis and allow endoscopists to explore lesions thoroughly. The traditional method of mapping is time-consuming and inaccurate. We aim to design a topographic mapping system via artificial intelligence to perform the job automatically.

Methods

The topographic mapping system was built using computer vision techniques. We enrolled 23 ESD cases at the Peking Union Medical College Hospital from September to November 2019. The reconstruction maps were created for each case using both the traditional approach and the system.

Results

Using the system, the time saved per case ranges from 34 to 3,336 s. Two approaches revealed no significant variations in the shape, size, or tumor area.

Conclusion

We developed an AI-assisted system that would help pathologists complete the ESD topographic mapping process rapidly and accurately.

The modern management of Barrett's oesophagus and related neoplasia: role of pathology

Modern management of Barrett's oesophagus and related neoplasia essentially focuses upon surveillance to detect early low-risk neoplastic lesions and offering organ-preserving advanced endoscopic therapies, while traditional surgical treatments of oesophagectomy and lymph node clearance with or without chemoradiation are preserved only for high-risk and advanced carcinomas. With this evolution towards figless invasive therapy, the choice of therapy hinges upon the pathological assessment for risk stratifying patients into those with low risk for nodal metastasis who can continue with less invasive endoscopic therapies and others with high risk for nodal metastasis for which surgery or other forms of treatment are indicated. Detection and confirmation of neoplasia in the first instance depends upon endoscopic and pathological assessment. Endoscopic examination and biopsy sampling should be performed according to the recommended protocols, and endoscopic biopsy interpretation should be performed applying standard criteria using appropriate ancillary studies by histopathologists experienced in the pathology of Barrett's disease. Endoscopic resections (ERs) are both diagnostic and curative and should be performed by clinicians who are skilled with advanced endoscopic techniques. Proper preparation and handling of ERs are essential to assess histological parameters that dictate the curative nature of the procedure. Those parameters are adequacy of resection and risk of lymph node metastasis. The risk of lymph node metastasis is determined by depth invasion and presence of poor differentiation and lymphovascular invasion. Those adenocarcinomas with invasion up to muscularis mucosae (pT1a) and those with superficial submucosal invasion (pT1b) up to 500 µ with no poor differentiation and lymphovascular invasion and negative margins may be considered cured by endoscopic resections.

Pathologic assessment of endoscopic resection specimens with superficial carcinoma of the esophagus: current practice and practical issues

Endoscopic resection (ER) has become the first-line therapy for early esophageal cancer and offers a treatment alternative to surgery, owing to less morbidity and better quality of life. ER techniques include endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). EMR is faster, simpler, and cheaper than ESD, but limited by its ability to resect lesions larger than 1.5 centimeters. Piecemeal EMR has limitations, including a high local recurrence rate and a suboptimal specimen for an accurate pathologic assessment. ESD, on the other hand, allows en bloc resections with negative (R0) margins, irrespective of lesion size, providing an excellent pathologic specimen, however, is technically challenging with a higher risk of complications. The evaluation of ER specimens in pathology varies slightly from institution to institution. Our review summarizes the current practices and issues in the pathologic assessment of esophageal ER specimens, which highlights the necessity of a systematic approach and standardization of both macroscopic and microscopic evaluation. There is a need for a comprehensive and standardized pathology report that will allow for uniform terminology for endoscopists, surgeons, and pathologists, which, in turn, will result in better treatment guidance.

Pathology definitions and resection strategies for early colorectal neoplasia: Eastern versus Western approaches in the post-Vienna era

There is a well-known discrepancy between East and West classifications of colorectal neoplasm, especially "intramucosal carcinoma," categorized as subgroup 4.4 in the Vienna classification, usually recognized as high-grade dysplasia in the United States and as carcinoma in situ in Japan. Focusing on management, in the current National Comprehensive Cancer Network algorithm, high-grade dysplasia, carcinoma in situ, and intramucosal carcinoma are managed similarly, whereas submucosal invasion by carcinoma requires en bloc resection. To bridge the differences with regard to these conceptual problems in the definition and management of carcinoma in situ and intramucosal carcinoma, endoscopists and pathologists from Japan and the United States gathered and discussed from their perspectives how to accurately assess specimens of en bloc/piecemeal resection and to effectively predict lymph node metastasis risk.

Pathologic Evaluation of Large Colorectal Endoscopic Submucosal Dissections: An Analysis of 279 Cases With Emphasis on the Importance of Multidisciplinary Work and Establishing Examination Protocols

Background. Endoscopic submucosal dissections (ESDs) allow removal of large gastrointestinal tumors and help patients avoid major oncologic surgery. In this study, the challenges and development of approaches toward successfully handling ESDs were analyzed in 279 colorectal specimens (114 rectal, 47 left, 118 right colonic; 90% adenoma with/without carcinoma). Methods. Each specimen was processed according to an established protocol including gross photography, mapping, and total submission for histopathologic examination. Results. Mean lesion size was 4.2 cm (range: 0.5-22 cm; 28% ≥5 cm; 6% ≥10 cm). Invasive carcinoma was present in 38 cases (14%), which had a mean overall tumor size of 3.8 cm (range: 1.1-17.5 cm), and mean largest size of the invasive component was 0.93 cm (range: 0.04-3 cm). Fifteen cases were staged as pT1a (submucosal invasion of <1000 µm) and 13 cases as pT1b (submucosal invasion of ≥1000 µm). En-bloc and R0 resection rates were 99.3% and 90.6%, respectively. Conclusion. Various histopathologic challenges were encountered, which were carefully evaluated by dedicated pathologists with familiarity to the subtleties in handling and reporting these specimens. We recommend these specimens to be prepared in the endoscopy suite, submitted to the Pathology Department oriented, pinned, and placed into copious amount of fixative. Total sampling, gross photography, mapping, and proper fixation are crucial components in the histopathologic evaluation. Micromeasurement of invasion depth and substaging per European/Japanese guidelines as well as accurate measurement of the distance from the resection margins are highly recommended. In conclusion, ESD is an adequate method that can be successfully implemented in a tertiary care center to perform en-bloc and margin-free resections of clinically selected large colorectal superficial lesions.

Effect of Preceding Biopsy on the Results of Endoscopic Submucosal Dissection for Colorectal Laterally Spreading Tumor

BACKGROUND

Forceps biopsies are usually performed before endoscopic submucosal dissection (ESD) for colonic laterally spreading tumors (LSTs). However, preceding biopsy is commonly believed to possibly inhibit complete tumor resection by causing blurring of tumor borders and tissue fibrosis.

AIMS

The aims were to investigate whether the preceding biopsy of colorectal LST affects the complete endoscopic tumor resection and increases the risk of complications.

METHODS

We retrospectively reviewed the medical records of patients with colorectal LSTs who underwent ESD at our center during an 8-year period. Patients were divided into two groups according to whether they underwent biopsy of the tumor before ESD. In addition, the characteristics of patients and tumors, including the completeness of tumor resection, were investigated.

RESULTS

Of 288 patients (174 men) enrolled in this study, 194 (67.4%, preceding biopsy group) underwent biopsies before ESD, whereas 94 (32.6%, no biopsy group) did not. There were no significant differences in age, sex, comorbidity, medication history, tumor location, and final pathologic result between both groups. Tumor size was larger (p = 0.002) and LST-G tumor was more common (p = 0.003) in the preceding biopsy group than in the no biopsy group. No significant difference was seen in ESD outcomes, including procedure time, hospitalization period, incidence of complications, en bloc resection rate, resection margin status, and incidence of surgical operation, between both groups.

CONCLUSIONS

Biopsy of LST is commonly performed before endoscopic resection. Contrary to popular belief, it does not increase the incomplete tumor resection rate and incidence of complications.

TRIAL REGISTRATION

KCT0002321.

Clinical outcomes of endoscopic submucosal tunnel dissection compared with conventional endoscopic submucosal dissection for superficial esophageal cancer: a systematic review and meta-analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) is the standard treatment for superficial esophageal cancer. However, it has limitations in case of large superficial esophageal squamous cell neoplasms (SESCNs), in which submucosal injection cannot attain satisfactory lifting effects. Thus, endoscopic submucosal tunnel dissection (ESTD) was introduced as a new treatment for SESCNs presenting satisfying results. Many studies have tried to verify the efficacy of ESTD, yet no meta-analysis has been published until now.

METHODS

We searched the databases of PubMed, Cochrane Library, Web of Science, SinoMed, Wanfang, and CNKI dating up to February 1, 2019. Studies comparing the clinical outcomes of ESTD and ESD for superficial esophageal cancers were enrolled. The Newcastle-Ottawa Quality Assessment Scale was used to evaluate the quality of these studies. Eight articles were included that involved a total of 625 superficial esophageal cancer patients.

RESULTS

Our analysis revealed that ESTD is superior to ESD as it has higher en bloc resection rate, shorter operation time, and lower recurrence rate 1 year after operation. The R0 resection rate and postoperative adverse event rate of ESTD group is comparable with ESD group.

CONCLUSIONS

Our study implicates that ESTD is a potentially superior treatment to ESD for superficial esophageal cancer.

Endoscopic Submucosal Dissection for Esophageal Adenocarcinoma: A North American Perspective

BACKGROUND

Data are limited regarding the application of endoscopic submucosal dissection (ESD) in Western countries or for esophageal adenocarcinoma in any part of the world. We sought to review our experience employing ESD in patients with early esophageal cancer at a high volume North American esophageal cancer treatment center.

METHODS

A prospectively maintained database of all patients with esophageal cancer treated at the McGill University Health Center was used to identify ESDs performed for adenocarcinoma between 2012 and 2016. Patient demographics, pre-resection tumor characteristics, endoscopic resection technical variables, pathologic results, and short- and long-term outcomes were recorded.

RESULTS

Of 650 patients in the database, 26 underwent 27 procedures. The majority (67%) had pre-treatment EUS. There were no post-ESD bleeding events requiring re-intervention. Perforation occurred in 2/27 (7%), one of which required operative repair. Complete RO resection was achieved in 18/27(67%). Salvage laparoscopic esophagectomy was performed in six patients. At a median follow-up of 18.5 (7-35) months, cancer recurrence occurred in only one patient who subsequently underwent successful repeat ESD.

CONCLUSIONS

Although technically challenging, ESD represents a safe and effective treatment of early esophageal adenocarcinoma and has the potential to become a more important tool in management of these early lesions in Western countries.

Comparison of endoscopic submucosal dissection with surgical gastrectomy for early gastric cancer: An updated meta-analysis

BACKGROUND

There are several surgical options for treating early gastric cancers (EGCs), such as endoscopic resection, laparoscopic or open gastrectomy with D1 or D2 lymphadenectomy. Endoscopic resection for EGC with low risk of lymph node metastasis has been widely accepted as a therapeutic alternative. The role of endoscopic submucosal dissection (ESD) in treating EGC is not well established, especially when compared with resection surgery cases in a long-term follow-up scope.

AIM

To compare the safety and efficacy of the short- and long-term outcomes between ESD and resection surgery.

METHODS

We searched the databases of PubMed, EMBASE, Web of Science, and the Cochrane Library from January 1990 to June 2018, enrolling studies reporting short- or long-term outcomes of ESD in comparison with resection surgery for EGC. The quality of the studies was assessed by the Newcastle-Ottawa Quality Assessment Scale. Stata software (version 12.0) was used for the analysis. Pooling analysis was conducted using either fixed- or random-effects models depending on heterogeneity across studies.

RESULTS

Fourteen studies comprising 5112 patients were eligible for analysis (2402 for EGC and 2710 for radical surgery). Our meta-analysis demonstrated that the ESD approach showed advantages through decreased operation time [weighted mean difference (WMD): -140.02 min, 95%CI: -254.23 to -34.82 min, P = 0.009], shorter hospital stay (WMD: -5.41 d, 95% CI: -5.93 to -4.89 d, P < 0.001), and lower postoperative complication rate [Odds ratio (OR) = 0.39, 95%CI: 0.28-0.55, P < 0.001). Meanwhile, EGC patients who underwent ESD had higher recurrence rate (OR = 9.24, 95%CI: 5.94-14.36, P < 0.001) than resection surgery patients. However, the long-term survival including overall survival [Hazard ratio (HR) = 0.51, 95%CI: 0.26-1.00, P = 0.05] and event-free survival (HR = 1.59, 95%CI: 0.66-9.81, P = 0.300) showed no significant differences between these two groups.

CONCLUSION

In the treatment of EGC, ESD was safe and feasible in comparison with resection surgery, with advantages in several surgical and post-operative recovery parameters. Although the recurrence rate was higher in ESD group, the long-term survival was still comparable in these two groups, suggesting ESD could be recommended as standard treatment for EGC with indications.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Optimal processing of ESD specimens to avoid pathological artifacts

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Transanal endoscopic microsurgical submucosa dissection in the treatment of rectal adenomas and T1 rectal cancer

Background

The treatment of flat rectal adenomas is challenging. The technical difficulty and the potential of malignancy in suspected benign lesions are the factors in question. Surgical and interventional endoscopic techniques are implemented in Europe without a clear strategy. To minimize recurrent adenoma and unclear histopathological work up en bloc excision is desirable.

Methods and results

We demonstrate in this article the transanal endoscopic microsurgical submucosa dissection (TEM-ESD) procedure as a feasible method for en bloc excision of rectal adenomas and early rectal cancer. The surgical technique is demonstrated in detail with the help of a video of the operation that is available online. The results of a consecutive series of 78 patients are presented.

Conclusion

TEM-ESD is a safe procedure for resection of rectal adenomas and low risk carcinomas. It offers the possibility of organ preservation and minimizes functional disturbances. In case of a necessary salvage operation, the preserved integrity of the rectal muscle tube grants maximal oncological safety.

Electronic supplementary material

The online version of this article (10.1007/s00053-018-0291-3) includes a video on the surgical technique: TEM ESD. The article and supplemental material are available at http://www.springermedizin.de/der-chirurg. The supplemental material can be found at the end of the article under “Supplementary material”.

Linked color imaging (LCI), a novel image-enhanced endoscopy technology, emphasizes the color of early gastric cancer

BACKGROUND AND STUDY AIMS

 Linked color imaging (LCI) and blue laser imaging (BLI) are novel image-enhanced endoscopy technologies with strong, unique color enhancement. We investigated the efficacy of LCI and BLI-bright compared to conventional white light imaging (WLI) by measuring the color difference between early gastric cancer lesions and the surrounding mucosa.

PATIENTS AND METHODS

 Images of early gastric cancer scheduled for endoscopic submucosal dissection were captured by LCI, BLI-bright, and WLI under the same conditions. Color values of the lesion and surrounding mucosa were defined as the average of the color value in each region of interest. Color differences between the lesion and surrounding mucosa (ΔE) were examined in each mode. The color value was assessed using the CIE L*a*b* color space (CIE: Commission Internationale d'Eclairage).

RESULTS

 We collected images of 43 lesions from 42 patients. Average ΔE values with LCI, BLI-bright, and WLI were 11.02, 5.04, and 5.99, respectively. The ΔE was significantly higher with LCI than with WLI ( P  < 0.001). Limited to cases of small ΔE with WLI, the ΔE was approximately 3 times higher with LCI than with WLI (7.18 vs. 2.25). The ΔE with LCI was larger when the surrounding mucosa had severe intestinal metaplasia ( P  = 0.04). The average color value of a lesion and the surrounding mucosa differed. This value did not have a sufficient cut-off point between the lesion and surrounding mucosa to distinguish them, even with LCI.

CONCLUSION

 LCI had a larger ΔE than WLI. It may allow easy recognition and early detection of gastric cancer, even for inexperienced endoscopists.

Handling and Pathology Reporting of Gastrointestinal Endoscopic Mucosal Resection

Endoscopic mucosal resection (EMR) is a non-invasive alternative to surgery that is now frequently used for resection of early lesions in both upper and lower parts of the gastrointestinal (GI) tract. One of the main advantages of these techniques is providing tissue for histopathological examination. Pathological examination of endoscopically resected specimens of GI tract is a crucial component of these procedures and is useful for prediction of both the risk of metastasis and lymph node involvement.

As the first step, it is very important for the pathologist to handle the EMR gross specimen in the correct way: it should be oriented, and then the margins should be labeled and inked accurately before fixation.

In the second step, the EMR pathological report should include all the detailed information about the diagnosis, grading, depth of invasion (mucosa only or submucosal involvement), status of the margins, and the presence or absence of lymphovascular invasion.

The current literature (PubMed and Google Scholar) was searched for the words "endoscopic mucosal resection" to find all relevant publications about this technique with emphasis on the pathologist responsibilities.

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

BACKGROUND AND STUDY AIMS

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Endoscopic resection of early gastric cancer: current status and new approaches

Endoscopic resection (ER) of early gastric cancer (EGC) has been an optimal treatment for selected patients. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Moreover, a new microscopic imaging for precise endoscopic diagnosis of EGC is introduced. This review covers the current status and new approaches of ER of EGC.

Experience with a new device for pathological assessment of colonic endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is gaining popularity worldwide in the treatment of neoplastic lesions of the gastrointestinal tract. However, the experience in Western countries is quite limited and restricted to large or academic centers. Besides, this approach requires an optimal pathological assessment. The aim of this study was to report our experience with colonic ESD using a new device that allows complete handling of the resected specimens and especially of lateral margins, for pathological analysis. In a 1-year period, 14 patients (6 men, 8 women, age range 50-82 years) underwent colonic ESD in a non-academic hospital. The endoscopic procedure was carried out successfully en bloc in more than 90 % of cases. Perforation requiring surgery occurred in one patient (7 %). Pathological assessment with the new device allowed entire and complete examination of both the deep and lateral margins of the excised specimens. Colonic ESD is a viable option for non-surgical treatment of large bowel lesions even in relatively small centers and in non-academic settings. The new device allows good handling of the specimens, and it seems to be useful for the entire examination of the resection margins.

Ever-changing endoscopic treatment for early gastric cancer: yesterday-today-tomorrow

Endoscopic resection has been an optimal treatment for selected patients with early gastric cancer (EGC) based on advances in endoscopic instruments and techniques. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC along with expanding ESD indication, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Recently, new techniques including ESD or endoscopic full-thickness resection combined with sentinel node navigation enable minimal tumor resection and a laparoscopic lymphadenectomy in cases of EGC with high risk of LNM. This review covers the development and challenges of endoscopic treatment for EGC. Moreover, a new microscopic imaging and endoscopic techniques for precise endoscopic diagnosis and minimally invasive treatment of EGC are introduced.

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.