Endoscopic mucosal resection

From advanced diagnosis to advanced resection in early neoplastic colorectal lesions: Never-ending and trending topics in the 2020s

Colonoscopy represents the most widespread and effective tool for the prevention and treatment of early stage preneoplastic and neoplastic lesions in the panorama of cancer screening. In the world there are different approaches to the topic of colorectal cancer prevention and screening: different starting ages (45-50 years); different initial screening tools such as fecal occult blood with immunohistochemical or immune-enzymatic tests; recto-sigmoidoscopy; and colonoscopy. The key aspects of this scenario are composed of a proper bowel preparation that ensures a valid diagnostic examination, experienced endoscopist in detection of preneoplastic and early neoplastic lesions and open-minded to upcoming artificial intelligence-aided examination, knowledge in the field of resection of these lesions (from cold-snaring, through endoscopic mucosal resection and endoscopic submucosal dissection, up to advanced tools), and management of complications.

Eine neue Traktionsvorrichtung (S-O-Clip) zur Erleichterung der endoskopischen Submukosa-Dissektion von Tumoren im Bereich der Ileozökalklappe

BACKGROUND

Endoscopic submucosal dissection (ESD) is a method that can be used for en bloc resection, regardless of the size and form of the lesion. The special location of ileocecal tumors leads to insufficient counter-traction and poor field of vision, making ESD difficult. An S-O clip has been developed to simplify the attachment procedure, eliminating interference with the endoscope and improving accessibility.

CASE PRESENTATION

The patient was a 70-year-old man who presented with abdominal pain and bloating. A colonoscopy revealed a flat-elevated-type lesion on the ileocecal valve, with the oral side of the lesion having progressed to the terminal ileum. The traction direction was adjusted from distal to proximal during the procedure using the S-O clip. Finally, with the help of the S-O clip, the tumor was safely removed and collected.

CONCLUSION

The S-O clip was successful in ESD of a colorectal tumor. By removing and re-anchoring the loaded ring, the S-O clips allowed the adjustment of traction direction from distal to proximal during ESD.

Comparison of sodium alginate-based and sodium hyaluronate-based submucosal injection materials based on rheological analysis

As a viscous high-performance submucosal injection material (SIM) used in endoscopic submucosal dissection (ESD), sodium alginate-based SIM (SA-SIM) was recently introduced as high-performance SIM equivalent to sodium hyaluronate-based SIM (HA-SIM) in Japan. However, a comprehensive, detailed comparison of SA and HA is yet to be performed. In this study, we precisely measured the viscoelastic properties, submucosal elevation height (SEH), and injection pressure (IP). Furthermore, we compared the outcomes of ESD using an ex vivo ESD model. There was no significant difference in SEHs between HA-SIM and SA-SIM at all post-injection times, and the IP of the SA-SIM injection was significantly higher than that of the HA-SIM injection in all conditions (P < 0.0001). The viscosity at high shear rates of SA-SIM was higher than that of HA-SIM; this result was consistent with SEH/IP measurement results. No significant difference was observed in ESD procedure time and total volume of injected SIM between HA-SIM and SA-SIM (18.1 ± 6.7 and 17.8 ± 6.0 min, P = 0.8987; 13.3 ± 5.3 and 11.6 ± 5.9 ml, P = 0.4658, respectively). Although SA-SIM was slightly more difficult to inject than HA-SIM, there was no significant difference in performance between the materials. Thus, this basic study demonstrated that SA-SIM can be used for endoscopic treatment as well as HA-SIM, and supported previous clinical research data.

Impact of observational training on endoscopic mucosal resection outcomes and competency for large colorectal polyps: single endoscopist experience

Background and study aims  Endoscopic mucosal resection (EMR) is standard treatment for large colorectal polyps. However, it is a specialized technique with limited data on the effectiveness of training methods to acquire this skill. The aim of this study was to evaluate the impact of observational training on EMR outcomes and competency in an early-stage endoscopist. Patients and methods  A single endoscopist completed comprehensive EMR training, which included knowledge acquisition and direct observation of EMR cases, and proctored supervision, during the third year of gastroenterology fellowship. After training, EMR was independently attempted on 142 consecutive, large (i. e., ≥ 20 mm), non-pedunculated colorectal polyps between July 2014 and December 2017 (mean age 61.7 years; mean polyp size 30.4 mm; en-bloc resection 55 %). Surveillance colonoscopy for evaluation of residual neoplasia was available for 86 % of the cases. Three primary outcomes were evaluated: endoscopic assessment of complete resection, rate of adverse events (AEs), and rate of residual neoplasia on surveillance colonoscopy. Results  Complete endoscopic resection was achieved in 93 % of cases, the rates of AEs and residual neoplasia were 7.8 % and 7.3 %, respectively. The rate of complete resection remained stable (at 85 % or greater) with increasing experience while rates of AEs and residual neoplasia peaked and decreased after 60 cases. Conclusions  An early-stage endoscopist can acquire the skills to perform effective EMR after completing observational training. At least 60 independent EMRs for large colorectal polyps were required to achieve a plateau for clinically meaningful outcomes.

Efficacy and safety of endoscopic submucosal dissection for non-ampullary duodenal polyps: A systematic review and meta-analysis

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is commonly used to treat early-stage digestive cancer because it results in a higher frequency of en-bloc resection and a lower frequency of local recurrence. However, the efficacy and safety of duodenal ESD remain unclear. Therefore, present study is aimed at evaluating clinical outcomes of duodenal ESD.

METHODS

To evaluate the efficacy and safety of duodenal ESD, electronic databases (MEDLINE, CENTRAL and EMBASE) were searched by two independent reviewers. The authors were contacted for additional information. A meta-analysis was performed to evaluate the efficacy and safety of duodenal ESD.

RESULTS

A total of 7 studies (203 patients) were included in the quantitative synthesis analysis. The pooled proportions of the frequencies of en-bloc resection, need for surgical intervention, bleeding, intraoperative perforation and delayed perforation were 87%, 4%, 2%, 15% and 2%, respectively. The quality of evidence regarding on surgical intervention outcomes was rated as moderate, whereas that of en-bloc resection was rated as low because of its marked inconsistency.

CONCLUSIONS

Duodenal ESD produced acceptable outcomes in terms of the en-bloc R0 resection, but the incidence of procedure-related adverse events is high (PROSPERO register, CRD42017057110).

Multimodal multiphoton imaging for label-free monitoring of early gastric cancer

Background

Early gastric cancer is associated with a much better prognosis than advanced disease, and strategies to improve prognosis is strictly dependent on earlier detection and accurate diagnosis. Therefore, a label-free, non-invasive imaging technique that allows the precise identification of morphologic changes in early gastric cancer would be of considerable clinical interest.

Methods

In this study, multiphoton microscopy (MPM) using two-photon excited fluorescence combined with second-harmonic generation was used for the identification of early gastric cancer.

Results

This microscope was able to directly reveal improved cellular detail and stromal changes during the development of early gastric cancer. Furthermore, two features were quantified from MPM images to assess the cell change in size and stromal collagen change as gastric lesion developed from normal to early cancer.

Conclusions

These results clearly show that multiphoton microscopy can be used to examine early gastric cancer at the cellular level without the need for exogenous contrast agents. This study would be helpful for early diagnosis and treatment of gastric cancer, and may provide the groundwork for further exploration into the application of multiphoton microscopy in clinical practice.

A New Ex Vivo Model for the Evaluation of Endoscopic Submucosal Injection Material Performance

Increasing the performance of submucosal injection materials (SIMs) is important for endoscopic therapy of early gastrointestinal cancer. It is essential to establish an ex vivo model that can evaluate SIM performance accurately, for developing high-performance SIMs. In our previous study, we developed a new ex vivo model that can be used to evaluate the performance of various SIMs in detail by applying constant tension to the specimen's ends. We also confirmed that the proposed new ex vivo model allows accurate submucosal elevation height (SEH) measurement under uniform conditions and detailed comparisons of the performances of various types of SIMs. Here, we describe the new ex vivo model and explain the detailed setup methodology of this model. Since all parts of the new model were easy to obtain, the setup of the new model could be completed quickly. SEH of various SIMs could be measured more accurately by using the new model. The critical factor that determines SIM performance can be identified using the new model. SIM development speed will drastically increase after the factor has been identified.

Identification of the critical viscoelastic factor in the performance of submucosal injection materials

High-performance submucosal injection materials (SIMs) contribute to the success of endoscopic therapy for early-stage gastrointestinal neoplasms. This study aimed to identify the most important factor (viscoelastic parameter) that determines SIM performance and the ease of injection. To determine the ideal viscoelastic parameters of SIMs, submucosal elevation heights (SEHs) and the ease of submucosal injection [characterized by injection pressures (IPs)] were evaluated using a newly developed ex vivo model, in which a constant tension was applied to the studied specimen. The strongest positive correlation was observed between the loss modulus determined at an oscillation frequency of 0.1 rad/s and SEH (correlation coefficient > 0.9) and between the loss modulus at 10 rad/s and IP (correlation coefficient > 0.9). SIMs with high loss moduli (0.1 rad/s) also contributed to maintenance of the submucosal elevation. Moreover, the SEHs of pseudoplastic fluid SIMs (whose loss moduli increased slightly with increasing angular frequency) were greater than those of Newtonian fluid SIMs (whose loss modulus increased drastically with increasing angular frequency). In this study, the ideal viscoelastic SIM parameters were clarified. The loss modulus (0.1 rad/s) was the most important viscoelastic factor affecting SIM performance. Additionally, the development of pseudoplastic fluid SIMs may lead to the creation of next-generation SIMs, with a performance superior to that of sodium hyaluronate, which is currently used widely in endoscopic treatments.

Development of a new ex vivo model for evaluation of endoscopic submucosal injection materials performance

BACKGROUND AND AIMS

Development of high-performance submucosal injection materials (SIMs) contribute to the advancement of endoscopic therapy for early-stage gastrointestinal neoplasms. This study aimed to develop a new ex vivo model that mimics the human gastrointestinal tract to evaluate the performance (the height and duration of the submucosal elevation) of various SIMs in detail.

METHODS

A new ex vivo model that applies a constant tension to the tested specimen (the porcine gastric specimen) was developed. SIMs were injected into the submucosa at the center or edge of the tested specimen, and submucosal elevation heights (SEHs) were measured over time.

RESULTS

The average value and standard deviation of SEH determined using the conventional model (the tested specimen was fixed with pins) were higher than those obtained using the new model, which showed that the new model could precisely measure the SEH of a given SIM. In addition, the performance (SEH) of SIMs decreased with increasing tension applied to the specimen, suggesting that the performance of SIMs deteriorates with the over-expansion of the gastrointestinal tract. The submucosal elevation formed at the specimen edge disappeared faster than that formed at the specimen's center.

CONCLUSIONS

The proposed new ex vivo model allows accurate SEH measurement under uniform conditions and detailed comparison of the performances of various types of SIMs and can contribute to the development of high-performance materials.

A feasibility study of photoacoustic imaging of ex vivo endoscopic mucosal resection tissues from Barrett's esophagus patients

BACKGROUND AND STUDY AIMS

Accurate endoscopic detection of dysplasia in patients with Barrett's esophagus (BE) remains a major clinical challenge. The current standard is to take multiple biopsies under endoscopic image guidance, but this leaves the majority of the tissue unsampled, leading to significant risk of missing dysplasia. Furthermore, determining whether there is submucosal invasion is essential for proper staging. Hence, there is a clinical need for a rapid in vivo wide-field imaging method to identify dysplasia in BE, with the capability of imaging beyond the mucosal layer. We conducted an ex vivo feasibility study using photoacoustic imaging (PAI) in patients undergoing endoscopic mucosal resection (EMR) for known dysplasia. The objective was to characterize the esophageal microvascular pattern, with the long-term goal of performing in vivo endoscopic PAI for dysplasia detection and therapeutic guidance.

MATERIALS AND METHODS

 EMR tissues were mounted luminal side up. The tissues were scanned over a field of view of 14 mm (width) by 15 mm (depth) at 680, 750, and 850 nm (40 MHz acoustic central frequency). Ultrasound and photoacoustic images were simultaneously acquired. Tissues were then sliced and fixed in formalin for histopathology with hematoxylin and eosin staining. A total of 13 EMR specimens from eight patients were included in the analysis, which consisted of co-registration of the photoacoustic images with corresponding pathologist-classified histological images. We conducted mean difference test of the total hemoglobin distribution between tissue classes.

RESULTS

 Dysplastic and nondysplastic BE can be distinguished from squamous tissue in 84 % of region-of-interest comparisons (42/50). However, the ability of intrinsic PAI to distinguish dysplasia from NDBE, which is the clinically important challenge, was only about 33 % (10/30).

CONCLUSION

 We demonstrated the technical feasibility of this approach. Based on our ex vivo data, changes in total hemoglobin content from intrinsic PAI (i. e. without exogenous contrast) can differentiate BE from squamous esophageal mucosa. However, most likely intrinsic PAI is unable to differentiate dysplastic from nondysplastic BE with adequate sensitivity for clinical translation.

Endoscopic management of mucosal lesions in the gastrointestinal tract

With the increasing role of endoscopy in patient evaluation, more mucosal lesions, including gastric, duodenal and colonic polyps, are encountered during routine examinations. It is imperative for gastroenterologists to become familiar with the endoscopic management of these various gastrointestinal lesions. In this article, various resection techniques will be discussed, including hot/cold forceps polypectomy, hot/cold snare polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection. The article will also discuss the evidence regarding the efficacy and safety of these techniques and the future direction of endoscopic management of mucosal lesions in the gastrointestinal tract.

Complete resection of colorectal adenomas: what are the important factors in fellow training?

BACKGROUND

The complete removal of adenomatous polyps is important for reducing interval cancer after colonoscopy.

AIMS

To identify factors affecting the completeness of colonoscopic polypectomies and to evaluate the experience level of fellows who achieve competence compared with that of experts.

METHODS

Medical records of 1,860 patients who underwent at least one polypectomy for an adenomatous polyp at Seoul National University Hospital between March 2011 and February 2013 were retrospectively reviewed. A total of 3,469 adenomatous polyps were included. The lateral and deep margins of the resected polyps were evaluated to check the resection completeness.

RESULTS

Of the 3,469 adenomatous polyps, 1,389 (40.0 %) were removed by two experts and 2,080 (60.0 %) were removed by seven fellows. In the expert-treated group, larger size [odds ratio (OR) 2.81 for ≥20 mm, 95 % confidence interval (CI) 1.64-4.84, P < 0.001] and right-sided location (OR 1.31, 95 % CI 1.05-1.63, P = 0.019) were associated with incomplete resection. In the fellow-treated group, not only polyp characteristics [right-sided location (OR 1.41, 95 % CI 1.18-1.69, P < 0.001)], but also the cumulative number of procedures was also related to resection completeness. After 300 polypectomies, the complete resection rate of the fellows was comparable to that of the experts.

CONCLUSIONS

In the fellow-treated group, the level of procedure experience was closely associated with the polypectomy outcomes. Meticulous attention is critical to ensure the completeness of polypectomies performed by trainee endoscopists during the training program.

Adverse events related to colonic endoscopic mucosal resection and polypectomy

Colonoscopy is a commonly performed procedure. The rate of adverse events is 2.8 per 1000 screening colonoscopies. These adverse events include cardiovascular and pulmonary events, abdominal pain, hemorrhage, perforation, postpolypectomy syndrome, infection, and death. Serious adverse events, such as hemorrhage and perforation, occur most frequently when colonoscopy is performed with polypectomy. This article highlights the prevention and management of adverse events associated with polypectomy and endoscopic mucosal resection of colonic lesions.

Gastric endoscopic submucosal dissection is safe for day patients

BACKGROUND/AIMS

Although the advantages of endoscopic submucosal dissection (ESD) are well established, there are important limitations that relate to its higher cost and higher rate of complications compared with endoscopic mucosal resection. This study assessed the therapeutic safety and efficacy of ESD in the treatment of small gastric dysplasia and early gastric cancer (EGC) located within the antrum in an outpatient setting, and it compared the results with those from patients admitted to hospital for ESD treatment.

METHODS

This study was a retrospective analysis of a prospectively maintained database. We reviewed consecutive patients with EGC or gastric dysplasia who underwent ESD between October 2007 and May 2008. The lesions were smaller than 2 cm and were located in the antrum. We analyzed 105 lesions in 105 patients. The patients were assigned to two groups according to each patient's preference.

RESULTS

The overall rates of complete resection were 98.1% in the inpatients group and 94.3% in the outpatients group. Immediate bleeding occurred in four inpatients, which included one patient in the outpatient group. Delayed bleeding occurred in one inpatient within 24 hours of the procedure. Macroperforations did not occur in either group. A microperforation was found in one outpatient.

CONCLUSIONS

The safety and efficacy of ESD used to treat small gastric tumors in the antrum in an outpatient setting appeared to be similar to the safety and efficacy of ESD used to treat patients who were admitted to the hospital.

Prospective clinical trial of traction device-assisted endoscopic submucosal dissection of large superficial colorectal tumors using the S-O clip

BACKGROUND

Endoscopic submucosal dissection (ESD) allows en bloc resection of superficial colorectal tumors regardless of size. However, ESD is technically difficult, hazardous, and time consuming. New devices may help overcome these drawbacks. We focused on traction methods and designed a new traction device, the "S-O clip." Its main advantage is that it allows direct visualization of the cutting line during submucosal dissection. Moreover, it can be used at any location without withdrawing the endoscope. The purpose of this study was to evaluate the efficacy and safety of traction device-assisted ESD for large colorectal tumors using the S-O clip.

METHODS

Between August 2010 and December 2011, ESD was performed in 70 patients with a superficial colorectal tumor ≥20 mm in diameter in our department. Patients were randomized into two groups: 27 cases in the S-O clip-assisted ESD group and 23 cases in the conventional ESD group. Included in the analysis were patient's gender and age, tumor form, size, and location, rate of en bloc resection, procedure time, presence or absence of intraoperative perforation or delayed bleeding, and pathological findings. Subgroup analysis stratified by these factors and multivariate analyses were conducted.

RESULTS

In the S-O clip-assisted ESD group, all 27 tumors were resected en bloc without any complications. Although a micro perforation occurred in one patient in the conventional ESD group, further surgical treatment was not required. None of the other 22 cases in the conventional ESD group experienced complications. The mean procedure time for the S-O clip-assisted ESD group was significantly shorter than for the conventional ESD group (37.4 ± 32.6 vs. 67.1 ± 44.1 min, p = 0.03). No significant between-group differences were found for the other factors.

CONCLUSION

Our results demonstrated that S-O clip-assisted ESD is safe and fast for en bloc resection of large superficial colorectal tumors.

Endoscopic submucosal dissection vs endoscopic mucosal resection for superficial esophageal cancer

AIM: To investigate the effectiveness of endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) in treating superficial esophageal cancer (SEC).

METHODS: Studies investigating the safety and efficacy of ESD and EMR for SEC were searched from the databases of Pubmed, Web of Science, EMBASE and the Cochrane Library. Primary end points included the en bloc resection rate and the curative resection rate. Secondary end points included operative time, rates of perforation, postoperative esophageal stricture, bleeding and local recurrence. The random-effect model and the fixed-effect model were used for statistical analysis.

RESULTS: Eight studies were identified and included in the meta-analysis. As shown by the pooled analysis, ESD had significantly higher en bloc and curative resection rates than EMR. Local recurrence rate in the ESD group was remarkably lower than that in the EMR group. However, operative time and perforation rate for ESD were significantly higher than those for EMR. As for the rate of postoperative esophageal stricture and procedure-related bleeding, no significant difference was found between the two techniques.

CONCLUSION: ESD seems superior to EMR in the treatment of SEC as evidenced by significantly higher en bloc and curative resection rates and by obviously lower local recurrence rate.

Follow-up outcomes of endoscopic resection for early gastric cancer with undifferentiated histology

BACKGROUND

The application of endoscopic resection (ER) for undifferentiated-type early gastric cancer (UD-EGC) remains controversial. The aim was to examine long-term outcomes of ER for UD-EGC. Furthermore, we investigated whether long-term outcomes of ER differed between poorly differentiated adenocarcinoma (PD) and signet ring cell carcinoma (SRC).

METHODS

From 2001 to 2011, 209 lesions in 209 patients with UD-EGC (82 PD; 127 SRC) were treated by ER. We retrospectively assessed the clinical outcomes of ER in 209 patients. The survival rate and disease-free survival rates after ER were evaluated as long-term outcomes.

RESULTS

The en bloc resection and curative resection (CR) rates were 91.4 and 55.0 %, respectively. The en bloc and CR rates in PD were 90.2 and 45.1 %, whereas those in SRC were 92.1 and 61.4 %. For patients with PD who underwent non-curative resections, 51.1 % were vertical-cut end-positive and for those with SRC, 63.3 % were lateral-cut end-positive, a statistically significant difference. In those patients where CR was achieved, no case of local recurrence or distant metastasis was observed during the follow-up period (32.7 ± 22.2 months). The 3- and 5-year survival rates were 99.0 and 98.6 %, with no significant difference between CR patients with SRC and PD.

CONCLUSIONS

ER may yield good long-term outcomes for UD-EGC if CR is achieved, with no difference between PD and SRC. However, to increase the current CR rate of ER, stricter criteria for performing ER in UD-EGC may be required.

Full thickness endoscopic resection of a colonic cancer: a case report

We present a case of a 40-year-old woman, diagnosed with a flat lesion (type 0-IIa+IIc) of the colon. There was a strong suspicion for submucosal invasion, however the patient initially refused surgical intervention. Therefore, the lesion was treated with full-thickness endoscopic resection. An over-the-scope clip device was applied to seal the resulting colonic wall defect. Histological examination demonstrated a T2 adenocarcinoma, therefore the patient agreed to a left hemicolectomy. Examination of the surgical specimen demonstrated no residual neoplasia or involvement of adjacent lymph nodes. We discuss the potential advantages and limitations of this new approach, which may be indicated for patients who are not surgical candidates.

Colon polypectomy: a review of routine and advanced techniques

The value of performing comprehensive screening colonoscopy with complete colon polypectomy is widely accepted. Colon cancer is a significant cause of worldwide mortality and prospective studies have proven that colonoscopic polypectomy reduces both the incidence and mortality related to this disease. Over the past few decades the array of instruments and techniques have greatly expanded to assist with the safe endoscopic removal of colon polyps. This article will review the published literature regarding efficacy and safety of standard polypectomy techniques such as snare polypectomy, electrocautery, and endoscopic mucosal resection along with newer techniques such as endoscopic submucosal dissection and combined laparoscopic techniques.

Long-term outcome of early gastric cancer after endoscopic submucosal dissection: expanded indication is comparable to absolute indication

BACKGROUND

Endoscopic submucosal dissection has become widely used for early gastric cancer with an expanded indication, although there is no strong consensus. We aimed to compare the clinical and long-term oncological outcome after endoscopic submucosal dissection according to indication.

METHODS

Retrospective review of 1152 patients with 1175 lesions who had undergone endoscopic submucosal dissection for early gastric cancer at tertiary educational hospital in Korea, between March 2005 and November 2011. Of these, 366 and 565 lesions were included in the absolute and expanded indication groups, respectively.

RESULTS

En bloc resection rates were not significantly different between the absolute and expanded indication groups. The complete resection rate was higher in the absolute indication group versus the expanded indication group (94.8% vs. 89.9%, respectively; P=0.008). In the expanded indication group, complete resection rate was higher in the differentiated versus undifferentiated tumour subgroups (92.9% vs. 78.4%, respectively; P<0.001). Recurrence rates were 7.7% in the absolute indication group vs. 9.3% in the expanded indication group (P=0.524). Disease-free survival was not significantly different between the two indication groups (P=0.634).

CONCLUSIONS

Endoscopic submucosal dissection for early gastric cancer with expanded indication is a feasible approach to disease management. Periodic endoscopic follow-up is necessary to detect cancer recurrence.

Cap-assisted EMR of large, sporadic, nonampullary duodenal polyps

BACKGROUND

EMR is an effective alternative to surgery for the removal of nonampullary duodenal polyps (NADPs). Cap-assisted EMR (EMR-C) has been rarely performed in the duodenum because of the risk of perforation.

OBJECTIVE

To evaluate the safety and effectiveness of EMR-C for the removal of large (≥ 15 mm) NADPs.

DESIGN

Retrospective study.

SETTING

Tertiary-care referral center.

PATIENTS

Between 2000 and 2010, 26 consecutive patients with sporadic NADPs underwent EMR-C.

INTERVENTION

EMR with the cap technique.

MAIN OUTCOME MEASUREMENTS

Complete eradication of polyps, complications, and recurrence.

RESULTS

A total of 14 sessile polyps (53.8%), 7 lateral spreading type nongranular tumors (26.9%), and 5 lateral spreading type granular tumors (19.2%) were treated. The median size of lesions was 15 mm. Five lesions involved one-half of the luminal circumference. Post-EMR histologic assessment showed low-grade dysplasia in 5 patients (19.2%) and high-grade dysplasia in 18 patients (69.2%). Three patients (11.5%) had well-differentiated endocrine tumors. Complete eradication was obtained in 25 of 26 (96%) patients. No perforations occurred. Three cases of intraprocedural bleeding were managed endoscopically. Median follow-up was 6 years (range 1-10 years). Residual adenomatous tissue was observed in 3 patients in lesions of 50 mm. In one of these cases, an adenocarcinoma occurred after 8 months, which was managed surgically.

LIMITATIONS

Retrospective design, single center.

CONCLUSION

This study supports the efficacy and safety of EMR-C for removing NADPs. Regular follow-up is mandatory because of the high risk of residual or recurrent adenomatous tissue and even cancer.

Three-dimensional MDCT for preoperative local staging of gastric cancer using gas and water distention methods: a retrospective cohort study

OBJECTIVE

The purpose of this article is to compare the T-staging accuracy and lesion detectability of MDCT with gas distention versus water distention according to the surgical and histopathologic findings, for the preoperative evaluation of gastric cancer.

MATERIALS AND METHODS

For a 3-month period, 113 consecutive patients (72 men and 41 women; age range, 23-85 years; mean age, 58 years) with 116 surgically confirmed gastric cancers from a single institution were included in our study. All patients had undergone preoperative MDCT with either effervescent granules taken orally (n = 55) or after having drunk 1,000 mL of tap water (n = 58) to create gastric distention. In addition to transverse images, multiplanar reformation images and 3D surface shaded display images were also obtained with gas distention CT, and multiplanar reformation images were obtained with water distention CT. The CT images were retrospectively reviewed by two abdominal radiologists separately with regard to T staging and lesion detectability. The accuracy values were compared between the two methods using Fisher's exact test.

RESULTS

The T-staging accuracy for gastric cancer did not differ significantly between gas distention and water distention CT scans, according to both radiologists (p > 0.05). Furthermore, the staging accuracy values for T1a cancers on gas distention CT scans for radiologists 1 and 2 were also comparable with those of water distention CT scans (91.1% vs 85% for radiologist 1 and 89.3% vs 85% for radiologist 2; p > 0.05). However, the tumor detection rate was significantly higher on gas distention CT scans using 2D and surface shaded display images for both radiologists (94.6% for radiologist 1 and 91.1% for radiologist 2), compared with the rates for water distention CT scans (78.3% and 73.3%) or gas distention CT scans using only 2D images (75.0% and 67.9%) (p < 0.05).

CONCLUSION

MDCT using the gas distention technique showed performance comparable to that of the water distention technique for the T staging of preoperative gastric cancer with better lesion detectability.

Cap-assisted endoscopic mucosal resection for colorectal polyps

PURPOSE

Cap-assisted endoscopic mucosal resection has been used to treat superficial esophageal and gastric cancers. Efficacy data in the colon are limited. The aim of the study was to evaluate the safety and efficacy of this technique in the treatment of sessile polyps and lateral spreading tumors in the colorectum.

METHODS

Two-hundred and fifty-five consecutive patients with sessile polyps or lateral spreading tumors >or=20 mm were treated between January 2000 and December 2007.

RESULTS

A total of 146 sessile polyps and 136 lateral spreading tumors were treated with cap-assisted endoscopic mucosal resection. Complications occurred in 22 (8.6%) patients (5.5% in sessile polyps and 10.3% in lateral spreading tumors). Intraprocedural bleeding occurred in 21 (7%) of polypectomies (6% in sessile polyps and 10% in lateral spreading tumors); all were controlled endoscopically. Postcoagulation syndrome occurred in 1 patient with lateral spreading tumor. No perforation occurred. Invasive adenocarcinoma was found in 35 patients, of whom 15 underwent surgery. Endoscopic follow-up in 200 patients with 216 adenomas for a median of 12.1 months showed recurrence in 8 (4%) who were treated with resection and/or ablation.

CONCLUSIONS

Cap-assisted endoscopic mucosal resection is an effective treatment for sessile polyps and lateral spreading tumors. A disadvantage of the technique is that the resection is piecemeal. Close surveillance provides the opportunity for additional tissue ablation, when required, to achieve complete lesion removal.

Rebamipide may be comparable to H2 receptor antagonist in healing iatrogenic gastric ulcers created by endoscopic mucosal resection: a prospective randomized pilot study

Endoscopic mucosal resection (EMR) results in the formation of iatrogenic gastric ulcers and the optimal treatments for such ulcers are still unclear. We aimed to evaluate the efficacy of rebamipide in the management of EMR-induced ulcers by comparing it with an H(2) receptor antagonist. After EMR, patients were randomly assigned into either rebamipide or famotidine groups. All patients received a one-week lansoprazole 30 mg q.d. therapy followed by three-week famotidine (20 mg b.i.d.) or rebamipide (100 mg t.i.d.) therapy. Four weeks after the treatments, ulcer sizes, stages, bleeding rates, and ulcer-related symptoms were compared using endoscopy and a questionnaire. A total of 63 patients were enrolled in this study. Finally, 51 patients were analyzed, 26 in rebamipide and 25 in famotidine group. Baseline characteristics were not significantly different between the two groups. Four weeks after EMR, the two groups were comparable in terms of ulcer reduction ratio (P=0.297), and ulcer stage (P=1.000). Moreover, no difference was observed with regard to ulcer-related symptoms, drug compliance, adverse drug event rates, and bleeding rates. Our data suggest that rebamipide is not inferior to famotidine in healing iatrogenic gastric ulcers, and could be a therapeutic option in the treatment of such ulcers.

Endoscopic mucosal resection for treatment of colorectal polyps occurring in the senium and presenium: a report of 561 cases

AIM: To investigate the efficacy of endoscopic mucosal resection (EMR) for colorectal polyps occurring in the senium and presenium, and analyze the clinical and pathological features of resected lesions as well as the indications for and the complications of EMR.

METHODS: A total of 513 patients with 766 lesions were included in this study. The "inject and cut]EMR technique was used. The resected lesions were observed pathohistologically. The patients were followed up for a period of 1 to 60 months to evaluate the efficacy of EMR. Intraoperative and postoperative complications and treatments were recorded.

RESULTS: A cure rate of 96.3% was achieved by EMR. Twenty-one patients (2.7%) were referred for surgery because of invasive cancer revealed by pathological examination after EMR. Bleeding occurred in 23 patients (4.2%) during EMR procedures, all of which underwent successful endoscopic hemostasis. Delayed bleeding occurred in ten patients (1.8%), of which seven underwent successful endoscopic hemostasis, and three received blood transfusion and conservative medical management. No perforation, infection and other complications occurred. The incidences of inflammatory polyps, hyperplastic polyps, adenomatous polyps and cancerous adenoma were 29.0%, 21.1%, 45.7% and 4.2%, respectively. The incidence of adenomatous polyps increased gradually with age. No recurrence was found during the follow-up period.

CONCLUSION: EMR is safe, minimally invasive, and more effective than traditional endoscopic approach in the treatment of colorectal polyps.

Endoscopic resection for undifferentiated early gastric cancer

BACKGROUND AND OBJECTIVE

Endoscopic resection (ER) has become an important curative option for early gastric cancer (EGC). However, the application of ER for undifferentiated EGC remains controversial. The aim of this study was to evaluate the clinicopathologic outcomes of ER performed in undifferentiated EGC with special reference to histopathologic subtypes to examine the feasibility of ER in undifferentiated EGC.

DESIGN AND SETTING

Retrospective, single-center study.

PATIENTS

From January 2001 to April 2007, 58 lesions in 58 patients with undifferentiated EGC (17 poorly differentiated adenocarcinoma; 41 signet-ring cell carcinoma) were treated by ER at Severance Hospital, Seoul, Korea.

MAIN OUTCOME MEASUREMENTS

The therapeutic efficacy of ER was assessed according to en bloc resection, histologic complete resection (CR), lateral or vertical cut end-positive (including submucosal invasion), and recurrence rates in 3- to 65-month follow-up periods.

RESULTS

The en bloc resection and CR rates were 84.5% and 67.2%, respectively. The en bloc and CR rates in poorly differentiated were 82.4% and 58.8%, whereas those in signet-ring cell were 85.4% and 70.7%, respectively. There were no significant differences between poorly differentiated and signet-ring cell. However, all (100%) of the histologic incomplete resections in poorly differentiated were vertical cut end-positive, whereas 83.3% of these resections in signet-ring cell were lateral cut end-positive. The recurrence rate was 5.1% in CR during the follow-up period.

LIMITATIONS

Retrospective, short-term follow-up period.

CONCLUSIONS

ER may be a feasible local treatment for undifferentiated EGC if CR can be achieved. However, a different approach is necessary between poorly differentiated and signet-ring cell before ER to prevent incomplete resection.

Endoscopic resection of superficial gastrointestinal tumors

Therapeutic endoscopy plays a major role in the management of gastrointestinal (GI) neoplasia. Its indications can be generalized into four broad categories; to remove or obliterate neoplastic lesion, to palliate malignant obstruction, or to treat bleeding. Only endoscopic resection allows complete histological staging of the cancer, which is critical as it allows stratification and refinement for further treatment. Although other endoscopic techniques, such as ablation therapy, may also cure early GI cancer, they can not provide a definitive pathological specimen. Early stage lesions reveal low frequency of lymph node metastasis which allows for less invasive treatments and thereby improving the quality of life when compared to surgery. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are now accepted worldwide as treatment modalities for early cancers of the GI tract.

Endoscopic resection for premalignant and malignant lesions of the gastrointestinal tract from the esophagus to the colon

The endoscopic mucosal resection and endoscopic submucosal dissection techniques, if performed with the right indications and with expertise, should be considered even in the West as elective treatment modalities for early gastrointestinal neoplasia. Because the experience is still limited, more should be done to strengthen the performance capacity and foster cooperation among skilled endoscopists.

Low frequency of bacteremia after an endoscopic resection for large colorectal tumors in spite of extensive submucosal exposure

BACKGROUND

During an EMR or endoscopic submucosal dissection (ESD) for colorectal tumors, an injection needle catheter is passed through the contaminated endoscopic channel and may directly inoculate bacteria into the blood stream during submucosal injection. In addition, extensively exposed submucosa, especially with an ESD, directly contacts colonic luminal bacteria after the procedure, which may increase the risk of bacteremia. However, the incidence of bacteremia after an EMR or ESD for colorectal tumors has not been reported.

OBJECTIVE

To evaluate the frequency of bacteremia associated with an EMR or ESD for colon lesions.

DESIGN

A prospective study.

PATIENTS

A total of 40 patients who underwent a conventional EMR (n = 30), an EMR after circumferential pre-cutting (n = 3), or ESD (n = 7) for colorectal tumors.

INTERVENTIONS AND MAIN OUTCOME MEASUREMENTS

Blood cultures were obtained immediately before, 5 minutes after, and 30 minutes after the procedure. Patients were closely monitored for 24 hours after the procedure to detect the development of infectious complications.

RESULTS

Blood cultures at baseline and 5 minutes after the procedure were all negative. However, a blood culture at 30 minutes after the procedure showed a positive result in 1 of 40 patients (2.5%). This patient underwent a conventional EMR, and the isolated microorganism was coagulase-negative Staphylococcus, which might be regarded as a contaminant. None of the 40 patients showed any signs or symptoms associated with infection.

LIMITATION

The small sample size.

CONCLUSIONS

An EMR, or even an ESD, for colon lesions may be considered a low-risk procedure for infectious complications that does not warrant prophylactic administration of antibiotics.

Depth of resection using two different endoscopic mucosal resection techniques

BACKGROUND AND STUDY AIMS

Endoscopic mucosal resection (EMR) has been carried out for high-grade dysplasia (HGD) and intramucosal carcinoma (IMCA) in Barrett's esophagus using two different cap-assisted techniques, the "inject, suck, and cut" and the "band and snare." Previous work has demonstrated comparable specimen diameters. However, the two techniques have not been previously compared with respect to depth of resection.

PATIENTS AND METHODS

From a database of patients with Barrett's esophagus, we identified 40 consecutive specimens removed using EMR from patients with HGD or IMCA, 20 each from the "inject, suck, and cut" and the "band and snare" techniques. Specimens were evaluated and measured separately by two pathologists for greatest diameter and depth, and for the presence of submucosa and muscularis propria at the deepest margin of resection. Follow-up data were collected regarding clinical outcome and stricture formation.

RESULTS

The mean depth of the specimens from the two techniques was not significantly different (0.51 cm vs. 0.50 cm, P = 0.76). All specimens contained substantial submucosa, allowing accurate staging of the neoplastic lesions resected. Muscularis propria was identified at the base of 65% of the "band and snare" and 50% of the "inject, suck, and cut" specimens (P = 0.52).

CONCLUSIONS

The "inject, suck, and cut" and "band and snare" techniques both yield equivalent adequate depth of histological specimens from Barrett's esophagus with HGD or IMCA, and both provide accurate pathological staging.

Retrieval of colorectal polyps following snare polypectomy: Experience of the multiple-suction technique in 602 cases

BACKGROUND

Retrieving colorectal polyp after endoscopic snare polypectomy is time consuming and possibly incurs a failure. The aim of the study was to assess the effectiveness of the multiple-suction (M-S) technique for retrieving a variety of polyps.

MATERIALS AND METHODS

Four hundred and nine cases received endoscopic snare polypectomy from January 2003 to January 2007 were reviewed. The resected polyps were retrieved by M-S technique, in which suction regarded as the leading technique, was taken in combination with channel occlusion, trap, snare, and grasping forcep. Time of cecal intubation and of polypectomy, total examination time, shape, size, location, and number of polyp(s) were recorded. Retrieval time and polyp lost rate were also noted.

RESULTS

A total of 602 polyps more than 3 mm in diameter underwent snare polypectomy. There were 96.7% (582/602) of polyps retrieved by the M-S technique. The mean retrieval time was 1.5 +/- 0.6 min. Time of polypectomy, retrieval time, and total examination time were significantly positive correlative with the number of polyps (P < 0.05). In a univariate analysis, longer retrieval time was significantly associated with larger polyps, more distant polyps from the anus, and a greater number of polyps, while higher polyp lost rate was significantly associated with sessile polyp, smaller polyps, and a greater number of polyps. In a multivariate analysis, retrieval time level (< or = 2.0 or >2.0 min) was linked to the number of polyps.

CONCLUSIONS

The M-S technique is proved to be reliable when used in the majority cases of colorectal polyp retrieval. In retrieving too many polyps, the M-S technique is time consuming, and hence, additional methods should be applied to improve its retrieval effectiveness.

Autologous blood as a submucosal fluid cushion for endoscopic mucosal therapies: results of an ex vivo study

OBJECTIVE

Submucosal injection of fluid is used to elevate lesions in order to prevent perforation, which is the most calamitous complication during endoscopic resection therapies. There are several injection options when performing mucosal elevation (normal saline (NS), sodium hyaluronate (SH), etc.). Submucosal injection of fresh, autologous blood offers some advantages because of its specific properties: corpuscular components ensure prolonged elevation and procoagulatory constituents prevent post-interventional bleeding. The purpose of this study was to compare the ex vivo performance of autologous blood as a submucosal fluid cushion (SFC) with that of NS, SH and DW (dextrose water).

MATERIAL AND METHODS

The proximal third of a resected porcine stomach was cut into squares. One millilitre NS, DW, SH and fresh porcine blood was injected into the submucosa. The height and duration of the submucosal injections were objectively measured during 1 h. Mucosal elevations were resected using an electro snare.

RESULTS

The initial height and width of the mucosal elevations were comparable for SH and blood, and significantly higher compared with NS and DW. Mucosal elevation after injecting autologous blood persisted significantly longer compared with NS (p <0.05), but did not differ from hyaluronate. Histopathological examination of the resected specimen confirmed the appropriate submucosal injection of these substances.

CONCLUSIONS

Submucosal injection of autologous blood with a standard endoscopic injection needle is possible and generates adequate mucosal elevation for the resection of high-quality specimens. This procedure could offer a "gratis" option for SFC as opposed to the expensive SH. Further clinical studies are needed to substantiate its use.

Endoscopic closure of cervical esophageal perforation caused by traumatic insertion of a mucosectomy cap

Cap-assisted endoscopic mucosal resection enables nonsurgical removal of superficial esophageal lesions. Perforation at the resection site is a rare but known complication of this technique. We report a case in which traumatic insertion of the mucosectomy cap led to perforation of the cervical esophagus. This complication has not been previously reported. The perforation was successfully closed by the endoscopic placement of clips.

State of the art on endoscopic mucosal resection and endoscopic submucosal dissection

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) provide new alternatives for minimally invasive treatment of superficial gastrointestinal malignancies. Evidence suggests that these techniques can be performed safely and have comparable outcomes to surgery with less morbidity and better quality of life due to their tissue-sparing nature when compared with conventional surgery. Although the techniques and accessories have become standardized, there is room for improvement, and further research and development are required. Current challenges facing American gastroenterologists or endoscopic surgeons include access to training and lack of appropriate reimbursement for these heavy-weighted and technically demanding procedures. Nevertheless, EMR and ESD are here to stay and are only the first steps toward true radical endoluminal resection of GI malignancies.

Endoscopic mucosal resection and endoscopic submucosal dissection as treatments for early gastrointestinal cancers in Western countries

Early gastrointestinal cancers are defined as lesions limited to the mucosa or submucosa without invading the muscularis propria, regardless of the presence of lymph node metastases. Although the natural history of these diseases is basically alike worldwide, its management is quite different between the East and West; aggressive surgery is frequently adopted by Western surgeons, while less invasive techniques are adopted by Asian colleagues. These techniques include endoscopic mucosal resection and endoscopic submucosal dissection which are now accepted as treatments for early gastrointestinal cancers in selected cases. Recent advances in endoscopic detection and treatment techniques, especially in Japan and Korea, have prompted Western endoscopists to learn these techniques. This review addresses recent advances regarding endoscopic resections of early gastrointestinal cancers, which promoted its use in Western countries. In addition, prospective studies on endoscopic resection in Western countries are also described.

Short- and long-term outcomes of standardized EMR of nonpolypoid (flat and depressed) colorectal lesions > or = 1 cm (with video)

BACKGROUND

Nonpolypoid (flat and depressed) colorectal lesions are increasingly recognized. Their endoscopic removal requires specialized EMR techniques, which are more complex to perform. Outcomes data on EMR of nonpolypoid neoplasms in the United States is needed.

OBJECTIVE

To determine the safety and efficacy of EMR in the resection of nonpolypoid colorectal neoplasms > or = 1 cm.

DESIGN

Retrospective analysis.

SETTING

Veterans Affairs Palo Alto Health Care System.

PATIENTS

Over a 5-year period, patients who underwent EMR for nonpolypoid colorectal lesions > or = 1 cm.

INTERVENTION

A standardized approach that included lesion assessment, classification, inject-and-cut EMR technique, reassessment, and treatment of residual tissue.

MAIN OUTCOME MEASUREMENTS

Complete resection, bleeding, perforation, development of advanced cancer, and death.

RESULTS

A total of 100 patients (125 lesions: 117 flat and 8 depressed) met inclusion criteria. Mean size was 16.7 +/- 7 mm (range, 10-50 mm). Histology included 5 submucosal invasive cancers, 5 carcinomas in situ, and 91 adenomas. Thirty-eight patients (48 lesions) did not receive surveillance colonoscopy: 8 had surgery, 16 had hyperplastic pathology, and 14 did not undergo repeat examination. Surveillance colonoscopy was performed on 62 patients (77 lesions). Complete resection was achieved in 100% of these patients after 1 to 3 surveillance colonoscopies. All patients received follow-up (mean [standard deviation] = 4.5 +/- 1.4 years); none developed colorectal cancer or metastasis.

LIMITATIONS

Single endoscopist, retrospective study.

CONCLUSIONS

A standardized EMR (inject-and-cut) technique is a safe and curative treatment option in nonpolypoid colorectal neoplasms (> or = 1 cm) in the United States.

64 multidetector-row computed tomography for preoperative evaluation of gastric cancer: histological correlation

OBJECTIVE

To assess the accuracy of 64 multidetector-row computed tomography (MDCT) in the diagnosis and staging of gastric cancer.

METHODS

This study was approved by the institutional review board, and the patients involved gave informed consent. Forty-four patients (34 men and 10 women; mean age, 57 years) with gastric carcinoma underwent preoperative 64 MDCT (SOMATOM Sensation 64; Siemens Medical System, Forchheim, Germany; slice collimation, 0.6 mm; slice width, 5 mm; feed/rotation, 23 mm; pitch factor, 1.2; kernel, B30f; and gantry speed, 0.5 second per rotation). Gastric distension was achieved by ingestion of 8 g of effervescent granules. Scanning was performed during arterial and portal phases, as determined with bolus tracking and automated triggering technique after intravenous administration of 100 mL of contrast materials (4 mL/s). All computed tomography scans were retrospectively reviewed by 2 radiologists. Each tumor was staged according to the TNM classification system. All patients underwent surgery. Computed tomography results were compared with histological staging of tumor invasion depth and regional lymph node metastasis.

RESULTS

The accuracy of 64 MDCT for detection of gastric cancer was 90% (18/20) and 100% (24/24) in early and advanced gastric cancer, respectively, with an overall detection rate of 95% (42/44). Its accuracy for determination of tumor penetration depth was 89% (16/18) and 88% (21/24) in early and advanced gastric cancer, respectively, with an overall accuracy of 88% (37/42). Its accuracy for determination of lymph node metastasis was 90% (18/20) and 71% (17/24) in early and advanced gastric cancer, respectively, with an overall accuracy of 80% (35/44).

CONCLUSIONS

The 64 MDCT is a promising technique for the detection and preoperative staging of gastric cancer.

Endoscopic resection of early gastric cancer

The purpose of this review is to examine recent advances in the techniques and technologies of endoscopic resection of early gastric cancer (EGC). Endoscopic mucosal resection (EMR) of EGC, with negligible risk of lymph node metastasis, is a standard technique in Japan and is increasingly becoming accepted and regularly used in Western countries. EMR is a minimally invasive technique which is safe, convenient, and efficacious; however, it is insufficient when treating larger lesions. The evidence suggests that difficulties with the correct assessment of depth of tumor invasion lead to an increase in local recurrence with standard EMR when lesions are larger than 15 mm. A major factor contributing to this increase in local recurrence relates to lesions being excised piecemeal due to the technical limitations of standard EMR. A new development in endoscopic techniques is to dissect directly along the submucosal layer -- a procedure called endoscopic submucosal dissection (ESD). This allows the en-bloc resection of larger lesions. ESD is not necessarily limited by lesion size and it is predicted to replace conventional surgery in dealing with certain stages of ECG. However, it still has a higher complication rate when compared to standard EMR, and it requires high levels of endoscopic skill and experience. Endoscopic techniques, indications, pathological assessment, and methods of endoscopic resection of EGC need to be established for carrying out appropriate treatment and for the collation of long-term outcome data.

A primer on natural orifice transluminal endoscopic surgery: building a new paradigm

Access to the abdominal cavity is required for diagnostic and therapeutic endeavors for a variety of medical and surgical diseases. Historically, abdominal access has required a formal laparotomy to provide adequate exposure. Natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery that eliminates abdominal incisions and incision-related complications by combining endoscopic and laparoscopic techniques to diagnose and treat abdominal pathology. During NOTES, commercially available flexible video endoscopes are used to create a controlled transvisceral incision via natural orifice access to enter the peritoneal cavity. Common incision-related complications such as wound infections, incisional hernias, postoperative pain, aesthetic disdain, and adhesions could be minimized or eliminated by NOTES. NOTES has evolved from more than 2 centuries of technological innovations and continued growth in the field of surgical endoscopy. Innovative surgical endoscopists have slowly developed means to surpass the constraints of the gastrointestinal lumen by using a flexible endoscope. The future of surgical endoscopy may be the shared entity of NOTES, which further integrates endoscopy, gastroenterology, and minimally invasive and general surgery. Although the promise of NOTES is electrifying to surgeons and endoscopists, several key issues need to be characterized prior to the incorporation of NOTES into routine practice. This article reviews the status, contemporary body of literature, limitations, and potential future implications accompanying the development of NOTES.

Endoscopic resection of early gastric cancer

The purpose of this review is to examine recent advances in the techniques and technologies of endoscopic resection of early gastric cancer (EGC). Endoscopic mucosal resection (EMR) of EGC, with negligible risk of lymph node metastasis, is a standard technique in Japan and is increasingly becoming accepted and regularly used in Western countries. EMR is a minimally invasive technique which is safe, convenient, and efficacious; however, it is insufficient when treating larger lesions. The evidence suggests that difficulties with the correct assessment of depth of tumor invasion lead to an increase in local recurrence with standard EMR when lesions are larger than 15 mm. A major factor contributing to this increase in local recurrence relates to lesions being excised piecemeal due to the technical limitations of standard EMR. A new development in endoscopic techniques is to dissect directly along the submucosal layer -- a procedure called endoscopic submucosal dissection (ESD). This allows the en-bloc resection of larger lesions. ESD is not necessarily limited by lesion size and it is predicted to replace conventional surgery in dealing with certain stages of ECG. However, it still has a higher complication rate when compared to standard EMR, and it requires high levels of endoscopic skill and experience. Endoscopic techniques, indications, pathological assessment, and methods of endoscopic resection of EGC need to be established for carrying out appropriate treatment and for the collation of long-term outcome data.

Endoscopic mucosal resection of large hyperplastic polyps in 3 patients with Barrett’s esophagus

AIM: To report the endoscopic treatment of large hyperplastic polyps of the esophagus and esophago-gastric junction (EGJ) associated with Barrett’s esophagus (BE) with low-grade dysplasia (LGD), by endoscopic mucosal resection (EMR).

METHODS: Cap fitted EMR (EMR-C) was performed in 3 patients with hyperplastic-inflammatory polyps (HIPs) and BE.

RESULTS: The polyps were successfully removed in the 3 patients. In two patients, with short segment BE (SSBE) (≤ 3 cm), the metaplastic tissue was completely excised. A 2 cm circumferential EMR was performed in one patient with a polyp involving the whole EGJ. A simultaneous EMR-C of a BE-associated polypoid dysplastic lesion measuring 1 cm x 10 cm, was also carried out. In the two patients, histologic assessment detected LGD in BE. No complications occurred. Complete neosquamous re-epithelialization occurred in the two patients with SSBE. An esophageal recurrence occurred in the remaining one and was successfully retreated by EMR.

CONCLUSION: EMR-C appears to be a safe and effective method for treating benign esophageal mucosal lesions, allowing also the complete removal of SSBE.

Endoscopic resection of early gastric cancer: the Japanese perspective

PURPOSE OF REVIEW

To examine recent advances in the techniques and technologies of endoscopic resection of early gastric cancer.

RECENT FINDINGS

Endoscopic mucosal resection of early gastric cancer with no risk of lymph node metastasis has been a standard technique in Japan and is increasingly becoming accepted and regularly used in Western countries. Though this minimally invasive technique is a safe, convenient and efficacious method, it is insufficient for larger lesions. Difficulties in correctly assessing the depth of tumour invasion and increases in local recurrence by standard endoscopic mucosal resection have been reported in lesions larger than 15 mm. This is because such lesions are often resected piecemeal due to the technical limitation of standard endoscopic mucosal resection. New developments in endoscopic resection techniques to dissect the submucosa directly, called endoscopic submucosal dissection, allows resections of larger lesions en bloc. There are no limitations in resection size in endoscopic submucosal dissection, which is expected to replace surgery. This technique, however, still has higher complications rates than standard endoscopic mucosal resection and requires highly skilled endoscopists.

SUMMARY

The techniques, indications, and pathological assessment methods of endoscopic resection of early gastric cancer are described so that proper treatment guidelines can be established and long-term outcome data can be assessed.