Giant Brunner's gland hyperplasia of the duodenum successfully resected en bloc by endoscopic mucosal resection: A case report

BACKGROUND Duodenal Brunner's gland hyperplasia(BGH)is a therapeutic target when complications such as bleeding or gastrointestinal obstruction occur or when malignancy cannot be ruled out.Herein,we present a case of large BGH treated with endoscopic mucosal resection(EMR).CASE SUMMARY An 83-year-old woman presented at our hospital with dizziness.Blood tests revealed severe anemia,esophagogastroduodenoscopy showed a 6.5 cm lesion protruding from the anterior wall of the duodenal bulb,and biopsy revealed the presence of glandular epithelium.Endoscopic ultrasonography(EUS)demonstr-ated relatively high echogenicity with a cystic component.The muscularis propria was slightly elevated at the base of the lesion.EMR was performed without complications.The formalin-fixed lesion size was 6 cm×3.5 cm×3 cm,showing nodular proliferation of non-dysplastic Brunner's glands compartmentalized by fibrous septa,confirming the diagnosis of BGH.Reports of EMR or hot snare polypectomy are rare for duodenal BGH>6 cm.In this case,the choice of EMR was made by obtaining information on the base of the lesion as well as on the internal characteristics through EUS.CONCLUSION Large duodenal lesions with good endoscopic maneuverability and no evident muscular layer involvement on EUS may be resectable via EMR.

Multicenter evaluation of recurrence in endoscopic submucosal dissection and endoscopic mucosal resection in the colon:A Western perspective

BACKGROUND While colon endoscopic mucosal resection(EMR)is an effective technique,removal of larger polyps often requires piecemeal resection,which can increase recurrence rates.Endoscopic submucosal dissection(ESD)in the colon offers the ability for en bloc resection and is well-described in Asia,but there are limited studies comparing ESD vs EMR in the West.AIM To evaluate different techniques in endoscopic resection of large polyps in the colon and to identify factors for recurrence.METHODS The study is a retrospective comparison of ESD,EMR and knife-assisted endoscopic resection performed at Stanford University Medical Center and Veterans Affairs Palo Alto Health Care System between 2016 and 2020.Knife-assisted endoscopic resection was defined as use of electrosurgical knife to facilitate snare resection,such as for circumferential incision.Patients≥18 years of age undergoing colonoscopy with removal of polyp(s)≥20 mm were included.The primary outcome was recurrence on follow-up.RESULTS A total of 376 patients and 428 polyps were included.Mean polyp size was greatest in the ESD group(35.8 mm),followed by knife-assisted endoscopic resection(33.3 mm)and EMR(30.5 mm)(P<0.001).ESD achieved highest en bloc resection(90.4%)followed by knife-assisted endoscopic resection(31.1%)and EMR(20.2%)(P<0.001).A total of 287 polyps had follow-up(67.1%).On follow-up analysis,recurrence rate was lowest in knife-assisted endoscopic resection(0.0%)and ESD(1.3%)and highest in EMR(12.9%)(P=0.0017).En bloc polyp resection had significantly lower rate of recurrence(1.9%)compared to non-en bloc(12.0%,P=0.003).On multivariate analysis,ESD(in comparison to EMR)adjusted for polyp size was found to significantly reduce risk of recurrence[adjusted hazard ratio 0.06(95%CI:0.01-0.57,P=0.014)].CONCLUSION In our study,EMR had significantly higher recurrence compared to ESD and knife-assisted endoscopic resection.We found factors including resection by ESD,en bloc removal,and use of circumferential incision were associated with significantly decreased recurrence.While further studies are needed,we have demonstrated the efficacy of ESD in a Western population.

Unlocking quality in endoscopic mucosal resection

A review of the development of the key performance metrics of endoscopic mucosal resection(EMR),learning from the experience of the establishment of widespread colonoscopy quality measurements.Potential future performance markers for both colonoscopy and EMR are also evaluated to ensure continued high quality performance is maintained with a focus service framework and predictors of patient outcome.

Expanding endoscopic boundaries:Endoscopic resection of large appendiceal orifice polyps with endoscopic mucosal resection and endoscopic submucosal dissection

BACKGROUND Large appendiceal orifice polyps are traditionally treated surgically.Recently,endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD)have been utilized as alternative resection techniques.AIM To evaluate the efficacy and safety of endoscopic resection techniques for the management of large appendiceal orifice polyps.METHODS This was a retrospective observational study conducted to assess the feasibility and safety of EMR and ESD for large appendiceal orifice polyps.This project was approved by the Baylor College of Medicine Institutional Review Board.Patients who underwent endoscopic resection of appendiceal orifice polyps≥1 cm from 2015 to 2022 at a tertiary referral endoscopy center in the United States were enrolled.The main outcomes of this study included en bloc resection,R0 resection,post resection adverse events,and polyp recurrence.RESULTS A total of 19 patients were identified.Most patients were female(53%)and Caucasian(95%).The mean age was 63.3±10.8 years,and the average body mass index was 28.8±6.4.The mean polyp size was 25.5±14.2 mm.74%of polyps were localized to the appendix(at or inside the appendiceal orifice)and the remaining extended into the cecum.68%of polyps occupied≥50%of the appendiceal orifice circumference.The mean procedure duration was 61.6±37.9 minutes.Polyps were resected via endoscopic mucosal resection,endoscopic submucosal dissection,and hybrid procedures in 5,6,and 8 patients,respectively.Final pathology was remarkable for tubular adenoma(n=10)[one with high grade dysplasia],sessile serrated adenoma(n=7),and tubulovillous adenoma(n=2)[two with high grade dysplasia].En bloc resection was achieved in 84%with an 88%R0 resection rate.Despite the large polyp sizes and challenging procedures,89%(n=17)of patients were discharged on the same day as their procedure.Two patients were admitted for post-procedure observation for conservative pain management.Eight patients underwent repeat colonoscopy without evidence of residual or recurrent adenomatous polyps.CONCLUSION Our study highlights how endoscopic mucosal resection,endoscopic submucosal dissection,and hybrid procedures are all appropriate techniques with minimal adverse effects,further validating the utility of endoscopic procedures in the management of large appendiceal polyps.

Efficacy and safety of endoscopic submucosal dissection for early gastric cancer and precancerous lesions in elderly patients

BACKGROUND With advancements in the development of endoscopic technologies,the endo-scopic submucosal dissection(ESD)has been one of the gold-standard therapies for early gastric cancer.AIM To investigate the efficacy and safety ESD in the treatment of early gastric cancer and precancerous lesions in the elderly patients.METHODS Seventy-eight elderly patients with early gastric cancer and precancerous lesions admitted to the Third Affiliated Hospital of Qiqihar Medical University were se-lected and classified into two groups according to the different surgical therapies they received between January 2021 and June 2022.Among them,39 patients treated with ESD were included in an experimental group,and 39 patients treated with endoscopic mucosal resection(EMR)were included in a control group.We compared the basic intraoperative conditions,postoperative short-term recovery,long-term recovery effects and functional status of gastric mucosa between the two groups;the basic intraoperative conditions included lesion resection,intra-operative bleeding and operation time;the postoperative short-term recovery assessment indexes were length of hospital stay and incidence of surgical complic-ations;and the long-term recovery assessment indexes were the recurrence rate at 1 year postoperatively and the survival situation at 1 year and 3 years postoper-atively;and we compared the preoperative and predischarge serum pepsinogen I(PG I)and PG II levels and PG I/PG II ratio in the two groups before surgery and discharge.RESULTS The curative resection rate and the rate of en bloc resection were higher in the experimental group than in the control group.The intraoperative bleeding volume was higher in the experimental group than in the control group.The operation time was longer in the experimental group than that in the control group,and the rate for base residual focus was lower in the experimental group than that of the control group,and the differences were all statistically significant(all P<0.05).The length of hospital stay was longer in the experi-mental group than in the control group,and the incidence of surgical complications,1-year postoperative recu-rrence rate and 3-year postoperative survival rate were lower in the experimental group than in the control group,and the differences were statistically significant(all P<0.05).However,the difference in the 1-year postoperative survival rate was not statistically significant between the two groups(P>0.05).Before discharge,PG I and PG I/PG II ratio were elevated in both groups compared with the preoperative period,and the above indexes were higher in the experimental group than those in the control group,and the differences were statistically significant(both P<0.05).Moreover,before discharge,PG II level was lower in both groups compared with the preoperative period,and the level was lower in the experimental group than in the control group,and the differences were all statistically significant(all P<0.05).CONCLUSION Compared with EMR,ESD surgery is more thorough.It reduces the rate of base residual focus,recurrence rate,surgical complications,and promotes the recovery of gastric cells and glandular function.It is safe and suitable for clinical application.

Hot snare polypectomy vs endoscopic mucosal resection using bipolar snare for intermediate size colorectal lesions:Propensity score matching

BACKGROUND Endoscopic resection(ER)with bipolar snare,in which the electric current only passes through the tissue between the device’s two electrodes,is a prominent method used to prevent perforation due to electricity potentially.ER using bipolar snare with or without submucosal injection enabled safe resection of colorectal lesions measuring 10-15 mm in an ex vivo porcine model.ER with bipolar snare is expected to have good treatment outcomes in 10-15 mm colorectal lesions,with high safety even without submucosal injection.However,no clinical reports have compared treatment outcomes with and without submucosal injection.AIM To compare the treatment outcomes of bipolar polypectomy with hot snare polypectomy(HSP)to those with endoscopic mucosal resection(EMR).METHODS In this single-centre retrospective study,we enrolled 10-15 mm nonpedunculated colorectal lesions(565 Lesions in 463 patients)diagnosed as type 2A based on the Japan Narrow-band Imaging Expert Team classification,resected by either HSP or EMR between January 2018 and June 2021 at the National Cancer Center Hospital East.Lesions were divided into HSP and EMR groups,and propensity score matching was performed.In the matched cohort,en bloc and R0 resection rates and adverse events were compared between the two groups.RESULTS Of the 565 lesions in 463 patients,117 lesions each in the HSP and EMR groups were selected after propensity score matching.In the original cohort,there was a significant difference in antithrombotic drug use(P<0.05),lesion size(P<0.01),location(P<0.01),and macroscopic type(P<0.05)between the HSP and EMR groups.In the matched cohort,the en bloc resection rates were comparable between both groups[93.2%(109/117)vs 92.3%(108/117),P=0.81],and there was no significant difference in the R0 resection rate[77.8%(91/117)vs 80.3%(94/117),P=0.64].The incidence of delayed bleeding was similar in both groups[1.7%(2/117)].Perforation occurred in the EMR group[0.9%(1/117)]but not in the HSP group.CONCLUSION Using bipolar snare,ER of nonpedunculated 10-15 mm colorectal lesions may be performed safely and effectively,even without submucosal injection.

Endoscopic mucosal resection with double band ligation versus endoscopic submucosal dissection for small rectal neuroendocrine tumors

BACKGROUND Endoscopic resection remains an effective method for the treatment of small rectal neuroendocrine tumors(NETs)(≤10 mm).Moreover,endoscopic mucosal resection(EMR)with double band ligation(EMR-dB),a simplified modification of EMR with band ligation,is an alternative strategy to remove small rectal NETs.AIM To evaluate the feasibility and safety of EMR-dB for the treatment of small rectal NETs(≤10 mm).METHODS A total of 50 patients with small rectal NETs,without regional lymph node enlargement or distant metastasis confirmed by endoscopic ultrasound,computerized tomography scan,or magnetic resonance imaging,were enrolled in the study from March 2021 to June 2022.These patients were randomly assigned into the EMR-dB(n=25)group or endoscopic submucosal dissection(ESD)group(n=25).The characteristics of the patients and tumors,procedure time,devices cost,complete resection rate,complications,and recurrence outcomes were analyzed.RESULTS There were 25 patients(13 males,12 females;age range 28-68 years old)in the EMR-dB group,and the ESD group contained 25 patients(15 males,10 females;age range 25-70 years old).Both groups had similar lesion sizes(EMR-dB 4.53±1.02 mm,ESD 5.140±1.74 mm;P=0.141)and resected lesion sizes(1.32±0.52 cm vs 1.58±0.84 cm;P=0.269).Furthermore,the histological complete resection and en bloc resection rates were achieved in all patients(100%for each).In addition,there was no significant difference in the complication rate between the two groups.However,the procedure time was significantly shorter and the devices cost was significantly lower in the EMRdB group.Besides,there was no recurrence in both groups during the follow-up period.CONCLUSION The procedure time of EMR-dB was shorter compared with ESD,and both approaches showed a similar curative effect.Taken together,EMR-dB was a feasible and safe option for the treatment of small rectal NETs.

Is endoscopic mucosal resection-precutting superior to conventional methods for removing sessile colorectal polyps?

We reviewed a study that reported a comparative analysis of the effects of endoscopic mucosal resection(EMR)precutting and conventional EMR for removing non-pedunculated,10-20 mm sized colorectal polyps.We identified some statistical deficiencies in this study.In addition,we believe that the differences between the treatments failed to achieve significance,and therefore,further analysis is required.

Editorial article to:Animal experimental study on magnetic anchor technique-assisted endoscopic submucosal dissection of early gastric cancer

In this editorial we comment on the article published in the recent issue of the World Journal of Gastrointestinal Endoscopy 2023;15(11):634-680.Gastric cancer(GC)remains the fifth most common malignancy and the fourth leading cause of cancer-related death worldwide.The overall prevalence of GC has declined,although that of proximal GC has increased over time.Thus,a significant proportion of GC cases and deaths can be avoided if preventive interventions are taken.Early GC(EGC)is defined as GC confined to the mucosa or submucosa.Endoscopic resection is considered the most appropriate treatment for precancerous gastrointestinal lesions improving patient quality of life,with reduced rates of complications,shorter hospitalization period,and lower costs when compared to surgical resection.Endoscopic mucosal resection(EMR)and endoscopic sub-mucosal dissection(ESD)are representative endoscopic treatments for EGC and precancerous gastric lesions.Standard EMR implies injection of a saline solution into the sub-mucosal space,followed by excision of the lesion using a snare.Complete resection rates vary depending on the size and severity of the lesion.When using conventional EMR methods for lesions less than 1 cm in size,the complete resection rate is approximately 60%,whereas for lesions larger than 2 cm,the complete resection rate is low(20%-30%).ESD can be used to remove tumors exceeding 2 cm in diameter and lesions associated with ulcers or submucosal fibrosis.Compared with EMR,ESD has higher en bloc resection rates(90.2%vs 51.7%),higher complete resection rates(82.1 vs 42.2%),and lower recurrence rates(0.65%vs 6.05%).Thus,innovative techniques have been introduced.

Endoscopic submucosal dissection vs endoscopic mucosal resection for early gastric cancer: A meta-analysis

AIM: To compare endoscopic submucosal dissection(ESD) and endoscopic mucosal resection(EMR) for early gastric cancer(EGC).METHODS: Computerized bibliographic search was performed on PubMed/Medline, Embase, Google Schol-ar and Cochrane library databases. Quality of each included study was assessed according to current Co-chrane guidelines. Primary endpoints were en bloc re-section rate and histologically complete resection rate. Secondary endpoints were length of procedure, post-treatment bleeding, post-procedural perforation and re-currence rate. Comparisons between the two treatment groups across all the included studies were performed by using Mantel-Haenszel test for fixed-effects mod-els(in case of low heterogeneity) or DerSimonian and Laird test for random-effects models(in case of high heterogeneity).RESULTS: Ten retrospective studies(8 full text and 2 abstracts) were included in the meta-analysis. Overall data on 4328 lesions, 1916 in the ESD and 2412 in the EMR group were pooled and analyzed. The mean operation time was longer for ESD than for EMR(stan-dardized mean difference 1.73, 95%CI: 0.52-2.95, P =0.005) and the "en bloc " and histological complete re-section rates were significantly higher in the ESD group [OR = 9.69(95%CI: 7.74-12.13), P < 0.001 and OR = 5.66,(95%CI: 2.92-10.96), P < 0.001, respectively]. As a consequence of its greater radicality, ESD provided lower recurrence rate [OR = 0.09,(95%CI: 0.05-0.17), P < 0.001]. Among complications, perforation rate was significantly higher after ESD [OR = 4.67,(95%CI, 2.77-7.87), P < 0.001] whereas the bleeding incidences did not differ between the two techniques [OR = 1.49(0.6-3.71), P = 0.39].CONCLUSION: In the endoscopic therapy of EGC, ESD showed a superior efficacy but higher complication rate with respect to EMR.

Management of a large mucosal defect after duodenal endoscopic resection

Duodenal endoscopic resection is the most difficult type of endoscopic treatment in the gastrointestinal tract(GI) and is technically challenging because of anatomical specificities. In addition to these technical difficulties, this procedure is associated with a significantly higher rate of complication than endoscopic treatment in other parts of the GI tract. Postoperative delayed perforation and bleeding are hazardous complications, and emergency surgical intervention is sometimes required. Therefore, it is urgently necessary to establish a management protocol for preventing serious complications. For instance, the prophylactic closure of large mucosal defects after endoscopic resection may reduce the risk of hazardous complications. However, the size of mucosal defects after endoscopic submucosal dissection(ESD) is relatively large compared with the size after endoscopic mucosal resection, making it impossible to achieve complete closure using only conventional clips. The over-the-scope clip and polyglycolic acid sheets with fibrin gel make it possible to close large mucosal defects after duodenal ESD. In addition to the combination of laparoscopic surgery and endoscopic resection, endoscopic full-thickness resection holds therapeutic potential for difficult duodenal lesions and may overcome the disadvantages of endoscopic resection in the near future. This review aims to summarize the complications and closure techniques of large mucosal defects and to highlight some directions for management after duodenal endoscopic treatment.

Endoloop ligation after endoscopic mucosal resection using a transparent cap: A novel method to treat small rectal carcinoid tumors

BACKGROUND Local endoscopic resection is an effective method for the treatment of small rectal carcinoid tumors, but remnant tumor at the margin after resection remains to be an issue.AIM To evaluate the efficacy and safety of resection of small rectal carcinoid tumors by endoloop ligation after cap-endoscopic mucosal resection(LC-EMR) using a transparent cap.METHODS Thirty-four patients with rectal carcinoid tumors of less than 10 mm in diameter were treated by LC-EMR(n = 22) or endoscopic submucosal dissection(ESD)(n =12) between January 2016 and December 2017. Demographic data, complete resection rates, pathologically complete resection rates, operation duration, and postoperative complications were collected. All cases were followed for 6 to 30 mo.RESULTS A total of 22 LC-EMR cases and 12 ESD cases were enrolled. The average age was48.18 ± 12.31 and 46.17 ± 12.57 years old, and the tumor size was 7.23 ± 1.63 mm and 7.50 ± 1.38 mm, respectively, for the LC-EMR and ESD groups. Resection time in the ESD group was longer than that in the LC-EMR group(15.67 ± 2.15 min vs 5.91 ± 0.87 min; P < 0.001). All lesions were completely resected at one time. No perforation or delayed bleeding was observed in either group.Pathologically complete resection(P-CR) rate was 86.36%(19/22) and 91.67%(11/12) in the LC-EMR and ESD groups(P = 0.646), respectively. Two of the three cases with a positive margin in the LC-EMR group received transanal endoscopic microsurgery(TEM) and tumor cells were not identified in the postoperative specimens. The other case with a positive margin chose follow-up without further operation. One case with remnant tumor after ESD received further local ligation treatment. Neither local recurrence nor lymph node metastasis was found during the follow-up period.CONCLUSION LC-EMR appears to be an efficient and simple method for the treatment of small rectal carcinoid tumors, which can effectively avoid margin remnant tumors.

Endoscopic mucosal resection of colorectal polyps in typical UK hospitals

AIM:To evaluate the outcomes of endoscopic mucosal resection(EMR) for colorectal polyps,with particular regard to procedural complications and recurrence rate,in typical United Kingdom(UK) hospitals that perform an average of about 25 colonic EMRs per year.METHODS:A total of 239 colorectal polyps(≥ 10 mm) resected from 199 patients referred to Rochdale Infirmary,Salford Royal Hospital and Royal Oldham Hospital for EMR between January 2003 and January 2009 were studied.RESULTS:The mean size of polyps resected was 19.6 ± 12.4 mm(range 10-80 mm).The overall major complication rate was 2.1%.Complications were less frequent with non-adenomas compared with the other groups(Pearson's χ 2 test,P < 0.0001).Resections of largersized polyps were more likely to result in complications(unpaired t-test,P = 0.021).Recurrence was associated with histology,with carcinoma-in-situ more likely to recur compared with low-grade dysplasia [hazard ratio(HR) 186.7,95% confidence interval(95% CI):8.81-3953.02,P = 0.001].Distal lesions were also more likely to recur compared with right-sided and transverse colon lesions(HR 5.93,95% CI:1.35-26.18,P = 0.019).CONCLUSION:EMR for colorectal polyps can be performed safely and effectively in typical UK hospitals.Stricter follow-up is required for histologically advanced lesions due to increased recurrence risk.

Endoscopic submucosal dissection vs endoscopic mucosal resection for colorectal tumors: A meta-analysis

AIM: To compare the efficacy and safety of endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) for the treatment of colorectal tumors.

Recurrence after endoscopic piecemeal mucosal resection for large sessile colorectal polyps

AIM: To evaluate the safety and outcomes of endoscopic piecemeal mucosal resection (EPMR) for large sessile colorectal polyps. METHODS: The patients enrolled in this study were 47 patients with 50 large sessile polyps (diameter, 2 cm or greater) who underwent EPMR using a submucosal saline injection technique between December 2002 and October 2005. All medical records, including characteristics of the patients and polyps, complications, and recurrences, were retrospectively reviewed. The first follow-up endoscopic examination was performed at 3-6 mo after initial endoscopic resection, and the second at 12 mo postEPMR. Subsequent surveillance colonoscopic examinations were individualized, taking risk factors into account. RESULTS: The patients were 23 men and 24 women,with a mean age of 60 years. Mean polyp size was 30.1 mm. Of 50 polyps identified, 34 (68%) were benign and 16 (32%) were malignant. There were 6 (12%) cases with EPMR-related bleeding: 5 intra-procedural and 1 early post-procedural bleeding. All bleeding episodes were managed by endoscopic clipping or argon beam coagulation. There were no perforations. Recurrence was identified in 5 cases (12.2%): 4 local recurrences detected at 3 mo post-EPMR and 1 local recurrence detected at 14 mo post-EPMR. The recurrence rate after EPMR was 3.1% for benign polyps and 33.3% for malignant polyps (P < 0.05). Median follow-up time was 37 mo. CONCLUSION: EPMR is safe, but should be applied carefully in malignant polyps. Close follow-up endoscopic examinations are necessary for early detection of recurrence.

Effect of prophylactic clip placement following endoscopic mucosal resection of large colorectal lesions on delayed polypectomy bleeding: A meta-analysis

BACKGROUND The role of prophylactic clipping for the prevention of delayed polypectomy bleeding(DPB) remains unclear and conclusions from prior meta-analyses are limited due to the inclusion of variety of resection techniques and polyp sizes.AIM To conduct a meta-analysis on the effect of clipping on DPB following endoscopic mucosal resection(EMR) of colorectal lesions ≥ 20 mm.METHODS We performed a search of PubMed and the Cochrane library for studies comparing the effect of clipping vs no clipping on DPB following endoscopic resection. The Cochran Q test and I^2 were used to test for heterogeneity. Pooling was conducted using a random-effects model.RESULTS Thirteen studies with a total of 7794 polyps were identified, of which data was available on 1701 cases of EMR of lesions ≥ 20 mm. Prophylactic clipping was associated with a lower rate of DPB(1.4%) when compared to no clipping(5.2%)(pooled OR: 0.24, 95%CI: 0.12-0.50, P < 0.001) following EMR of lesions ≥ 20 mm.There was no significant heterogeneity among the studies(I^2 = 0%, P = 0.67).CONLUSION Prophylactic clipping may reduce DPB following EMR of large colorectal lesions.Future trials are needed to further identify risk factors and stratify high risk cases in order to implement a cost-effective preventive strategy.

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).

Endoscopic mucosal resection of early gastric cancer: Experiences in Korea

Endoscopic mucosal resection （EMR） has been established as one of the treatment options for early gastric cancer （EGC）. However, there are many uncertain areas such as indications of EIR, best treatment methods, management of complications and follow-up methods after the procedure. Host studies on this topic have been carried out by researchers in Japan. In Korea, gastric cancer is the most common malignant disease, and the second leading cause of cancer death. In these days, EIR for EGC is widely performed in many centers in Korea. In this review, we will provide an overview of the bechniques and outcomes of EIR in Korea.

Risk factors for bleeding after endoscopic mucosal resection

AIM： To clarify the risk factors for bleeding after endoscopic mucosal resection （EMR）. METHODS： A total of 297 consecutive patients who underwent EMR were enrolled. Some of the patients had multiple lesions. Bleeding requiring endoscopic treatment was defined as bleeding after EMR. Odds ratios （OR） with 95% confidence intervals （CI）, calculated by logistic regression with multivariate adjustments for covariates, were the measures of association. RESULTS： Of the 297 patients, 57 （19.2%） patients with bleeding after EMR were confirmed. With multivariate adjustment, the cutting method of EMR, diameter, and endoscopic pattern of the tumor were associated with the risk of bleeding after EMR. The multivariate-adjusted OR for bleeding after EMR using endoscopic aspiration mucosectomy was 3.07 （95%CI, 1.59-5.92） compared with strip biopsy. The multiple-adjusted OR for bleeding after EMR for the highest quartile （16-50 mm） of tumor diameter was 5.63 （95%CI, 1.84-17.23） compared with that for the lowest （4-7 mm）. The multiple-adjusted OR for bleeding after EMR for depressed type of tumor was 4.21 （95%CI, 1.75-10.10） compared with elevated type. CONCLUSION： It is important to take tumor charactedstics （tumor size and endoscopic pattern） and cutting method of EMR into consideration in predicting bleeding after EMR.

Endoscopic mucosal resection for rectal carcinoids under micro-probe ultrasound guidance

AIM: To assess the therapeutic value of endoscopic mucosal resection (EMR) under micro-probe ultrasound guidance for rectal carcinoids less than 1 cm in diameter. METHODS: Twenty-one patients pathologically diagnosed with rectal carcinoids following colonoscopy in our hospital from January 2007 to November 2012 were included in this study. The patients consisted of 14 men and 7 women, with a mean age of 52.3 ± 12.2 years (range: 36-72 years). The patients with submucosal tumors less than 1 cm in diameter arising from the rectal and muscularis mucosa detected by micro-probe ultrasound were treated with EMR and followed up with conventional endoscopy and micro-probe ultrasound. RESULTS: All of the 21 tumors were confirmed by micro-probe ultrasound as uniform hypoechoic masses originating from the rectal and muscularis mucosa, without invasion of muscularis propria and vessels, and less than 1 cm in diameter. EMR was successfully completed without bleeding, perforation or other complications. The resected specimens were immunohistochemically confirmed to be carcinoids. Patients were followed up for one to two years, and no tumor recurrence was reported. CONCLUSION: EMR is a safe and effective treatment for rectal carcinoids less than 1 cm in diameter.