Outcomes of endoscopic submucosal dissection for esophageal cancer with segmental absence of intestinal musculature.

BACKGROUND AND AIMS: Perforation during esophageal endoscopic submucosal dissection (ESD) typically results from electrical damage. However, there are cases in which perforation occurs because of segmental absence of intestinal musculature (SAIM) without iatrogenic muscular injury. We investigated the occurrence rate and clinical course of SAIM during esophageal ESD. METHODS: We conducted a retrospective review of esophageal ESDs performed between 2013 and 2019 at 10 centers in Japan. RESULTS: Five of 1708 (0.29%) patients received ESD for esophageal cancer and had SAIM. The median muscular defect size was 20 mm. All lesions were resected without discontinuation. After resection, 3 patients were closed with Endoloop. Four patients had mediastinal emphysema. All patients were managed conservatively. CONCLUSIONS: SAIM is a very rare condition that is usually only diagnosed during ESD. Physicians performing esophageal ESD should be aware of SAIM. When SAIM is detected, the ESD technique should be modified to prevent full-thickness perforation.

Long-Term Outcomes of Endoscopic Submucosal Dissection for Early Remnant Gastric Cancer: A Retrospective Multicenter Study.

INTRODUCTION: Favorable long-term outcomes of endoscopic submucosal dissection (ESD) for early remnant gastric cancer (ERGC) have been reported in single-center studies from advanced institutions. However, no studies have examined the long-term outcomes using a multicenter database. This study aimed to investigate the long-term outcomes of the aforementioned approach using a large multicenter database. METHODS: This retrospective multicenter cohort study included 242 cases with 256 lesions that underwent ESD for ERGC between April 2009 and March 2019 across 12 centers. We investigated the long-term outcomes of these patients with the Kaplan-Meier method, and the relationship between curability, additional treatment, or hospital category, and the survival time was evaluated using the log-rank test. RESULTS: During the median follow-up period of 48.4 months, the 5-year overall survival rate was 81.3%, and the 5-year gastric cancer-specific survival rate was 98.1%. The survival time of patients of endoscopic curability (eCura) C-2 without additional surgery was significantly shorter than the corresponding of patients of eCura A/B/C-1 and eCura C-2 with additional surgery. There was no significant difference in either overall survival or gastric cancer-specific survival rate between the high-volume and non-high-volume hospitals. CONCLUSION: The gastric cancer-specific survival of ESD for ERGC using a multicenter database was favorable. ESD for ERGC is widely applicable regardless of the hospital case volume. Management in accordance with the latest guidelines will lead to long-term survival.

Endoscopic resection for gastric submucosal tumors: Japanese multicenter retrospective study.

OBJECTIVES: Limited information is available on the efficacy and safety of endoscopic resection (ER) of gastric submucosal tumors (SMTs) in Japanese endoscopic practice where ER for gastric tumors is extremely popular. METHODS: We conducted this study to elucidate the current scenario of ER for gastric SMTs in Japanese endoscopic practice. Patients (from 12 institutions) with gastric SMTs who underwent ER were enrolled from the first case until August 2020. RESULTS: We enrolled 117 patients with 118 lesions. The number of patients who underwent ER increased over the years. The mean endoscopic tumor size was 20 ± 7.2 (8-40) mm. The growth type was primarily intraluminal (90%). The mean resection and wound closure times were 58 ± 38 (range, 12-254) min and 31 ± 41 (range, 3-330) min, respectively. Complete ER was achieved for 117 (99%) lesions. Full-thickness resection rate was 44%; however, only 12 (10%) patients required abdominal paracentesis for decompression. Endoscopic treatments were completed in 115 (97%) lesions, while three lesions required conversions to laparoscopic surgery due to luminal collapse, uncontrolled bleeding, and difficulty in defect closure. Gastrointestinal stromal tumors were the most common pathology (74%). No recurrence was observed during the mean follow-up period of 4.3 ± 2.9 years. The 5-year overall survival rate was 98.9% (95% confidence interval 97.8-100%). CONCLUSION: Performance of ER for gastric SMTs is increasing in Japan. The technique seems feasible in Japanese endoscopic practice, warranting further validation in a prospective study.

Endoscopic full-thickness resection for gastric submucosal tumors: Japanese multicenter prospective study.

OBJECTIVES: Early gastric cancer endoscopic resection (ER) is prominent in Japan. However, evidence regarding ER of gastric submucosal tumors (SMT) is limited. This prospective multicenter phase II study investigated the efficacy and safety of endoscopic full-thickness resection (EFTR) for gastric SMT. METHODS: Endoscopic full-thickness resection indication for gastric SMT was 11-30 mm, histologically proven or clinically suspicious (irregular margin, increasing size, or internal heterogeneity) gastrointestinal stromal tumors (GIST), with no ulceration and intraluminal growth type. The primary end-point was the complete ER (ER0) rate, with a sample size of 42. RESULTS: We enrolled 46 patients with 46 lesions between September 2020 and May 2023 at seven Japanese institutions. The mean ± SD (range) endoscopic tumor size was 18.8 ± 4.5 (11-28) mm. The tumor resection and defect closure times were 54 ± 26 (22-125) min and 33 ± 28 (12-186) min, respectively. A 100% ER0 was achieved in all 46 patients. The EFTR procedure was accomplished in all patients without surgical intervention. One patient had delayed perforation and was managed endoscopically. GIST accounted for 76% (n = 35) of the cases. R0, R1, and RX rates were 33 (77%), 3 (6.5%), and 7 (15%), respectively. CONCLUSION: Endoscopic full-thickness resection for gastric SMT of 11-30 mm is efficacious. It warrants further validation in a large-scale cohort study to determine the long-term outcome of this treatment for patients with gastric GIST.

Assessment of predictive factors associated with the technical difficulty of endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma: Japanese multicenter retrospective study.

OBJECTIVES: Endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell carcinoma (ESCC) is performed for the treatment of lesions with varied backgrounds and factors. However, the predictive factors associated with the technical difficulty of ESD remain unknown in patients with varied lesions. Therefore, this study aimed to identify the predictive factors associated with the technical difficulty of ESD for ESCC using a retrospective cohort. METHODS: This multicenter, retrospective study was conducted in 10 hospitals in Japan. Consecutive patients who underwent esophageal ESD between January 2013 and December 2019 were enrolled. Lesions of subepithelial tumors, adenocarcinoma, and adenoma were excluded. Difficult lesions were defined as ESD requiring a long procedure time (≥120 min), perforation development, piecemeal resection, or discontinued ESD. In the present study, the clinical factors were assessed to identify the technical difficulty of ESD using univariate and multivariate analyses. RESULTS: Among 1708 lesions treated with esophageal ESD, eight subepithelial tumors, 44 adenocarcinomas, and two adenomas were excluded. Finally, 1505 patients with 1654 lesions were analyzed, and 217 patients with 217 lesions (13.1%) were classified as patients with difficult lesions. In multivariate analysis, the predictive factors associated with the technical difficulty of ESD were as follows: tumors with varices, tumors with diverticulum, antiplatelet use (discontinued), circumference of tumor (≥1/2), preoperative tumor size ≥30 mm, trainee, and nonhigh-volume center. CONCLUSION: This multicenter retrospective study identified the predictive factors associated with the technical difficulty of ESD for ESCC with varied backgrounds and factors.

Evaluation of trefoil factor 3 as a non-invasive biomarker of gastric intestinal metaplasia and gastric cancer in a high-risk population.

BACKGROUND: Adenocarcinoma is preceded by chronic atrophic gastritis, gastric intestinal metaplasia and dysplasia. Trefoil factor 3 (TFF3) is a peptide secreted by goblet cells, which is abundantly present in intestinal metaplasia. AIM: To evaluate the utility of serum TFF3 as a non-invasive biomarker for the diagnosis of intestinal metaplasia and gastric cancer. METHODS: Single-center, cross-sectional study of 274 patients who consecutively underwent upper gastrointestinal endoscopy with gastric biopsies (updated Sydney system). TFF3 levels were measured in serum by a commercial ELISA kit. Patients with normal histology or chronic atrophic gastritis without intestinal metaplasia comprised the control group. In addition, 14 patients with invasive gastric cancer were included as a reference group. The association between TFF3 levels and intestinal metaplasia was assessed by logistic regression. RESULTS: Patients with intestinal metaplasia (n=110) had a higher median TFF3 level as compared to controls (n=164), 13.1 vs. 11.9ng/mL, respectively (p=0.024). Multivariable logistic regression showed a no significant association between TFF3 levels and intestinal metaplasia (OR=1.20; 95%CI: 0.87-1.65; p-trend=0.273). The gastric cancer group had a median TFF3 level of 20.5ng/mL, and a significant association was found (OR=3.26; 95%CI: 1.29-8.27; p-trend=0.013). CONCLUSION: Serum levels of TFF3 do not discriminate intestinal metaplasia in this high-risk Latin American population. Nevertheless, we confirmed an association between TFF3 levels and invasive gastric cancer.

Safety and efficacy of endoscopic submucosal dissection for superficial esophageal cancer with esophageal varices.

BACKGROUND: Heavy drinking is associated with esophageal cancer and esophageal varices. However, there are limited reports of endoscopic resection for esophageal cancer with esophageal varices. In this multicenter study, we clarified the safety and efficacy of endoscopic submucosal dissection for superficial esophageal cancer with esophageal varices. METHODS: In this multicenter, retrospective, observational study, patients underwent esophageal endoscopic submucosal dissection at 10 referral centers in Japan from January 2013 to December 2019. We analyzed characteristics including backgrounds and varices, treatment outcomes, and adverse events in cases with esophageal varices. RESULTS: A total of 1708 patients were evaluated, 27 (1.6%) of whom had esophageal varices. In patients with esophageal varices, the en bloc resection rate and R0 resection rate were 100% and 77.8%, respectively. Patients with esophageal varices had longer procedure times than patients without esophageal varices (p = 0.015). There was no significant difference in adverse events. There was no significant difference in procedure time and number of adverse events between patients who underwent pretreatment and those who did not. There was no significant difference in these outcomes for patients with lesions on varices compared to those without. Child-Pugh classification and location of the lesions also did not affect these outcomes. CONCLUSIONS: Esophageal cancer with esophageal varices could be treated endoscopically safely and effectively.

The risk scoring system for assessing the technical difficulty of endoscopic submucosal dissection in cases of remnant gastric cancer after distal gastrectomy.

BACKGROUND: Endoscopic submucosal dissection (ESD) for remnant gastric cancer (RGC) after distal gastrectomy (DG) is considered technically challenging due to the narrow working space, and severe fibrosis and staples from the previous surgery. Technical difficulties of ESD for RGC after DG have not been thoroughly investigated. This study aimed to develop and validate a risk-scoring system for assessing the technical difficulty of ESD for RGC after DG in a large multicenter cohort. METHODS: We investigated patients who underwent ESD for RGC after DG in 10 institutions between April 2008 and March 2018. A difficult case was defined as ESD lasting ≥ 120 min, involving piecemeal resection, or the occurrence of perforation during the procedure. A risk-scoring system for the technical difficulty of the procedure was developed based on multiple logistic regression analyses, and its performance was internally validated using bootstrapping. RESULTS: A total of 197 consecutive patients with 201 lesions were analyzed. There were 90 and 111 difficult and non-difficult cases, respectively. The scoring model consisted of four independent risk factors and points of risk scores were assigned for each as follows: tumor size > 20 mm: 2 points; anastomosis site: 2 points; suture line: 1 point; and non-expert endoscopist: 2 points. The C-statistics of the scoring system for technical difficulty was 0.72. CONCLUSIONS: We developed a validated risk-scoring model for predicting the technical difficulty of ESD for RGC after DG that can contribute to its safer and more reliable performance.

Feasibility and Safety of Endoscopic Submucosal Dissection for Recurrent Rectal Lesions that after Transanal Endoscopic Microsurgery: A Case Series.

OBJECTIVES: Recently, several studies have demonstrated the usefulness of endoscopic submucosal dissection (ESD) for residual or locally recurrent colorectal lesions after endoscopic treatment. However, the feasibility of ESD for recurrent rectal lesions after transanal endoscopic microsurgery (TEM) has not been fully investigated. In this study, we evaluated the feasibility and safety of ESD for recurrent rectal lesions after TEM. METHODS: The treatment outcomes of 10 lesions in 9 patients, who underwent ESD between January 2006 and March 2018 for recurrent rectal lesions after transanal endoscopic microsurgery, were evaluated. RESULTS: All lesions were successfully resected en bloc, and the R0 resection rate was 90%. The median size of the resected specimens and lesions (range) was 44 mm (21-70) and 27.5 mm (5-60), respectively. The pathological diagnoses included 4 adenomas and 6 cancerous lesions. The cancerous lesions included 5 cases of mucosal cancer and 1 case of superficial submucosal invasive cancer (depth of submucosal invasion <1,000 µm from the muscularis mucosae). No adverse events occurred. There was no recurrence during the follow-up period. CONCLUSIONS: ESD for recurrent rectal lesions after TEM by expert's hands appears to be safe and feasible.

Development and validation of an endoscopic submucosal dissection video assessment tool.

BACKGROUND: Despite a need for assessment of endoscopic submucosal dissection (ESD) skills in order to track progress and determine competence, there is no structured measure of assessing competency in ESD performance. The present study aims to develop and examine validity evidence for an assessment tool to evaluate the recorded performance of ESD for gastric neoplasms. METHODS: The ESD video assessment tool (EVAT) was systematically developed by ESD experienced endoscopists. The EVAT consists of a 25-item global rating scale and 3-item checklist to assess competencies required to perform ESD. Five unedited videos were each evaluated by 2-blinded experienced ESD endoscopists to assess inter-rater reliability using intraclass correlation coefficients (ICC). Seventeen unedited videos in total were rated by 3 blinded experienced ESD endoscopists. Validity evidence for relationship to other variables was examined by comparing scores of inexperienced (fellows) and experienced endoscopists (attending staff), and by evaluating the relationship between the EVAT scores and ESD case experience. Internal consistency was evaluated using Cronbach's alpha. RESULTS: The inter-rater reliability for the total score was high at 0.87 (95% confidence interval 0.11 to 0.99). The total score [median, interquartile range (IQR)] was significantly different between the inexperienced (71, 63-77) and experienced group (95, 91-97) (P = 0.005). The total scores demonstrated high correlation with the number of ESD cases (Spearman's ρ = 0.79, P < 0.01). The internal consistency was 0.97. CONCLUSIONS: This study provides preliminary validity evidence for the assessment of video-recorded ESD performances for gastric neoplasms using EVAT.

Endoscopic plombage with polyglycolic acid sheets and fibrin glue for gastrointestinal fistulas.

BACKGROUND AND STUDY AIMS: Gastrointestinal (GI) fistulas arise as adverse events of GI surgery and endoscopic treatment as well as secondary to underlying diseases, such as ulceration and pancreatitis. Until a decade ago, they were mainly treated surgically or conservatively. Bioabsorbable polyglycolic acid (PGA) sheets and fibrin glue, which are commonly used in surgical procedures, have also recently been used in endoscopic procedures for the closure of GI defects. However, there have only been few case reports about successful experiences with this approach. There have not been any case-series studies investigating the strengths and weaknesses of such PGA sheet-based treatment. In this study, we evaluated the clinical effectiveness of using PGA sheets to close GI fistulas. PATIENTS AND METHODS: Cases in which patients underwent endoscopic filling with PGA sheets and fibrin glue for GI fistulas at Kobe University Hospital between January 2013 and April 2018 were retrospectively reviewed. RESULTS: A total of 10 cases were enrolled. They included fistulas due to leakage after GI surgery, aortoesophageal/bronchoesophageal fistulas caused by chemoradiotherapy, or severe acute pancreatitis. The fistulas were successfully closed in 7 cases (70%). The unsuccessful cases involved a fistula due to leakage after surgical esophagectomy and bronchoesophageal fistulas due to chemoradiotherapy or severe acute pancreatitis. Unsuccessful treatment was related to fistula epithelization. CONCLUSION: Endoscopic plombage with PGA sheets and fibrin glue could be a promising therapeutic option for GI fistulas.

Clinical outcomes of endoscopic submucosal dissection for superficial esophageal neoplasms extending to the cervical esophagus.

BACKGROUND: The feasibility and safety of endoscopic submucosal dissection (ESD) for superficial esophageal neoplasms extending to the cervical esophagus currently remain unknown because of the limited number of cases. We aimed to clarify the clinical outcomes of these cases. METHODS: This was a case series study conducted at a single institution that enrolled 26 consecutive patients with superficial esophageal neoplasms extending to the cervical esophagus who underwent ESD between July 2003 and December 2015. RESULTS: En bloc and complete resection rates were both 100 % and no major intraprocedural complications occurred. Thirteen patients were treated with prophylactic steroid therapy. The incidence of postoperative stricture in patients with a circumferential mucosal defect of more than three-quarters was 72.7 %. Four patients required entire circumferential resection, with perforation occurring after endoscopic balloon dilation (EBD) in two and EBD being required for more than 1 year in the other two. CONCLUSIONS: ESD including the cervical esophagus is technically feasible. Circumferential resection may cause refractory postoperative stricture or post-EBD perforation, so needs to be avoided where possible.

Proton Pump Inhibitors Increase the Susceptibility of Mice to Oral Infection with Enteropathogenic Bacteria.

BACKGROUND AND AIMS: Proton pump inhibitors (PPIs) are among the most frequently prescribed medications. Side effects including an increased risk of intestinal infections have been reported. It is assumed that PPIs can increase susceptibility to enteropathogens; however, the underlying mechanisms are unknown. Here in this study, we explored whether Lansoprazole (Laz), one of the PPIs, increases the susceptibility to enteropathogens, and further investigated the mechanism of it. METHODS: Mice were administered Laz intraperitoneally once daily and orally infected with Citrobacter rodentium (C. rodentium). The establishment of intestinal infection was assessed by histology and inflammatory cytokine expression levels measured by quantitative PCR. To test whether Laz changes the intestinal environment to influence the susceptibility, intestinal pH, microbiota, metabolites and immune cell distributions were evaluated via pH measurement, 16S rRNA gene sequencing, metabolome, and flow cytometry analyses after Laz administration. RESULTS: Colitis was induced with less C. rodentium in Laz-treated mice as compared with the controls. We found that increased numbers of C. rodentium could reach the cecum following Laz administration. Laz increased pH in the stomach but not in the intestines. It induced dysbiosis and changed the metabolite content of the small intestine. However, these changes did not lead to alterations of immune cell distribution. CONCLUSIONS: Laz raised susceptibility to C. rodentium as increased numbers of the pathogen reach the site of infection. Our results suggest that it was due to increased stomach pH which allowed more peroral enteropathogens to pass the stomach, but not because of changes of intestinal environment.

Clinical outcomes of deep invasive submucosal colorectal cancer after ESD.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is a reliable method that can replace surgery under certain conditions. However, limited information is available on the clinical course of T1b colorectal cancer (CRC) after ESD. The aim of the study was to clarify the feasibility of ESD for T1b CRC. PATIENTS AND METHODS: Three hundred and two patients with 312 T1 CRC were identified in this retrospective cohort study. All patients were treated with ESD, other endoscopic treatments, or surgery. In this study, we (I) investigated the en bloc resection rate of ESD and (II) compared the overall survival (OS) rate for patients who underwent ESD with additional surgery (Group A) and surgery without upfront endoscopic resection (Group B) for T1b CRC. RESULTS: No significant differences were observed in the en bloc resection rates between T1b and T1a CRC (100 vs. 98.7%), but the en bloc R0 resection rate was significantly lower in T1b CRC than in T1a CRC (64.7 vs. 97.4%). Regarding complications, perforations occurred in 2.9% of patients with T1b CRC, which was not significantly different from the rate of 5.3% in patients with T1a CRC. No significant differences were observed in the OS or recurrence-free survival (RFS) curves between Groups A and B (OS rates at 5 years: 92.3 vs. 88.9%, RFS rates at 5 years: 81.4 vs. 85.3%). Similarly, the 5-year disease-specific survival (DSS) rate of Group A was identical to that of Group B (both 100%). CONCLUSIONS: ESD for T1b CRC before surgery is a possible strategy because of the low rate of complications and favorable long-term outcomes.

A comparison of the clinical outcomes of esophagectomy and chemoradiotherapy after noncurative endoscopic submucosal dissection for esophageal squamous cell carcinoma.

PURPOSE: Endoscopic submucosal dissection (ESD) is widely used to treat esophageal cancer, but some patients require additional treatment due to the possibility of lymph node metastasis. The aim of this study was to elucidate the clinical outcomes of these additional treatments. METHODS: The study included 59 patients who developed superficial esophageal squamous cell carcinoma after noncurative ESD treated between 2005 and 2016, of whom 28 underwent esophagectomy and 31 received chemoradiotherapy (CRT). RESULTS: The median follow-up periods were 45 months in the esophagectomy group and 41 months in the CRT group. The overall survival did not differ significantly between the groups (P = 0.46). However, there were no recurrences in the esophagectomy group, and the disease-specific survival rate was significantly higher in this group (P = 0.042). Among the patients at high risk for recurrence due to massive tumor invasion (≥ SM2) with lymphovascular invasion (esophagectomy group, six patients; CRT group, ten patients), none in the esophagectomy group had recurrence, whereas four in the CRT group died of esophageal cancer (P = 0.031). CONCLUSION: The overall survival did not differ significantly between the groups. However, compared with CRT, esophagectomy provided more favorable disease control for patients with massive tumor invasion (≥ SM2) with lymphovascular invasion.

Two penetrating vessels as a novel indicator of the appropriate distal end of peroral endoscopic myotomy.

BACKGROUND AND AIM: One of the challenges during peroral endoscopic myotomy (POEM) is ensuring the appropriate length of myotomy on the gastric side. To determine the appropriate distal end of the gastric myotomy, we focused on the two penetrating vessels (TPVs) found in the gastric cardia during POEM. In the present study, we evaluated whether the TPVs could serve as an accurate indicator of the appropriate distal end of the gastric myotomy. METHODS: All patients who underwent POEM between March and August 2016 were included for this study. When making the submucosal tunnel in the 5 o'clock direction into the stomach, two vessels penetrating through the circular muscle along the edge of oblique muscle in the cardia can be exposed. We designated these two vessels as TPVs. The myotomy was extended until the second TPVs was exposed. The anal end of the submucosal tunnel was confirmed by the double-scope POEM technique, and the length from the gastroesophageal junction to the anal side end of the myotomy was measured by the scale on the endoscope. RESULTS: Among 37 patients who underwent myotomy in the 5 o'clock position, TPVs were found in 34 patients (91.2%). Sufficient submucosal tunneling on the gastric side was confirmed by the double-scope POEM technique in these 34 patients. Median length of the gastric myotomy was 3.0 cm (range 2-4 cm). CONCLUSION: TPVs appears to be a simple and reliable indicator to determine the appropriate distal end of myotomy.

Efficacy of a new hemostatic forceps during gastric endoscopic submucosal dissection: A prospective randomized controlled trial.

BACKGROUND AND AIM: Currently, endoscopic submucosal dissection (ESD) is a widely accepted standard treatment for early gastric cancer, but one challenging aspect of ESD is hemostasis. We developed a new hemostatic forceps (FD-Y0007) with the aim of achieving more effective hemostasis and investigated the hemostatic ability of the FD-Y0007 during gastric ESD in humans. METHODS: This study was a prospective randomized controlled trial, which was conducted at a cancer referral center. Sixty-six patients who were scheduled to undergo ESD were enrolled and randomly assigned to either the Coagrasper or the FD-Y0007, which was used for hemostasis throughout the case. The primary end point was the time required to obtain hemostasis, which was measured for the first episode of bleeding during each case. RESULTS: Hemostasis time for the first bleeding episode during ESD was 73.0 s for the Coagrasper and 21.5 s for the FD-Y0007 (P < 0.001). When all episodes of bleeding were included, hemostasis time was 56.8 s in the Coagrasper group and 25.5 s in FD-Y0007group (P < 0.0001). The frequency of adverse events (perforation: 3.4% vs 7.1%; delayed bleeding: 0% vs 0%) was not significantly different between the two groups. CONCLUSIONS: Compared with the Coagrasper, the FD-Y0007 efficiently reduces the hemostatic time during gastric ESD with no increase in adverse events.

Feasibility and safety of endoscopic submucosal dissection for lesions involving the ileocecal valve.

BACKGROUND AND STUDY AIM: Endoscopic submucosal dissection (ESD) has been applied to treat early colorectal cancers. The aim of this study was to clarify the clinical course of ESD for lesions involving the ileocecal valve (ICV) by evaluating the successful resection rates, and the risk and frequency of adverse events. PATIENTS AND METHODS: The outcome of ESD on 38 ICV lesions was compared with the outcome of 132 cecal lesions that did not involve the ICV or appendiceal orifice during the same study period. The factors related to longer procedure time, postoperative stricture development, and tumor recurrence were investigated for ESD of ICV lesions. RESULTS: There was no significant difference between the ICV and non-ICV groups in the en block resection rates. The median procedure time was significantly longer in the ICV group than in the non-ICV group, with a point estimate of the difference of 37 minutes (95 % confidence interval [CI] 20.00 to 56.00; P  < 0.01). None of the patients developed symptomatic post-ESD stricture or tumor recurrence. ESD procedure duration was ≥ 120 minutes in 16 lesions and < 120 minutes in 22 lesions of the ICV group. A specimen diameter of ≥ 40 mm and tumor extension into terminal ileum were factors related to a longer procedure time (odds ratio [OR] 8.40, 95 %CI 1.53 to 46.10, P = 0.01; OR 10.60, 95 %CI 2.17 to 51.40, P  < 0.01, respectively). CONCLUSIONS: ICV lesions can be resected by ESD without major adverse events or causing symptomatic stricture development. However, ESD for ICV lesions should be performed only by expert endoscopists, as the procedure requires accomplished endoscopic skill and experience.