Feasibility Of Endoscopic Submucosal Dissection Research Articles

Risk of lymph node metastasis and feasibility of endoscopic submucosal dissection in undifferentiated-type early gastric cancer

BackgroundWhether endoscopic submucosal dissection (ESD) applies to undifferentiated-type early gastric cancer (UEGC) remains controversial. We aimed to analyze the risk factors for lymph node metastasis (LNM) in UEGC and evaluate the feasibility of ESD.MethodsThis study included 346 patients with UEGC who underwent curative gastrectomy between January 2014 and December 2021. Univariate and multivariate analyses of the correlation between clinicopathological features and LNM were conducted, and the risk factors for exceeding the expanded ESD indications were evaluated.ResultsThe overall LNM rate in UEGC was 19.94%. Among the preoperatively assessable factors, submucosal invasion (odds ratio [OR] = 4.77, 95% confidence interval [CI]: 2.14–10.66) and > 2 cm(OR = 2.49, 95% CI: 1.20–5.15) were independent risk factors for LNM, while postoperative independent risk factors were > 2 cm (OR = 3.35, 95% CI: 1.02–5.40) and lymphovascular invasion(OR = 13.21, 95% CI: 5.18–33.70). Patients who met the expanded indications had a low LNM risk (4.1%). Additionally, tumors located in the cardia (P = 0.03), non-elevated type (P < 0.01) were independent risk factors for exceeding the expanded indications in UEGC.ConclusionsESD may be applicable for UEGC meeting the expanded indications, and preoperative evaluation should be cautious when the lesion is non-elevated type or located in the cardia.Trial registrationChinese Clinical Trial Registry (12/05/2022 ChiCTR2200059841).

Endoscopic Submucosal Dissection for Early Gastric Cancer in Patients Aged 85 Years Old or Older Is Associated with a Good Prognosis Compared to Conservative Treatment without Any Invasive Procedure

Introduction: Studies have reported the feasibility of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in elderly people with respect to both short- and long-term outcomes. As the elderly population in society increases, the requirement for managing super-elderly patients aged ≥85 years with EGC will also increase. This study aims to identify the long-term clinical outcomes of ESD for clinical T1N0 EGC in patients aged ≥85 years. Methods: A total of 370 consecutive patients aged ≥85 years with clinical T1N0 EGC who were managed in 11 institutions were reviewed retrospectively. On the basis of treatment strategy, we compared the overall survival (OS) and disease-specific survival (DSS) after performing propensity score-matched analysis between patients undergoing ESD (ESD group) and those not undergoing treatment (conservative treatment group). The potential prognostic factors were also investigated in the propensity score-matched patients. Results: After propensity score matching, we found that the 3-year OS and DSS rates were significantly higher in the ESD group than in the conservative treatment group (OS, 82.2% vs. 50.5%; p < 0.001; DSS, 100% vs. 80.1%; p = 0.008). Furthermore, ESD was identified as a significant factor for prolonged OS, whereas Charlson comorbidity index (CCI) ≥3 and prognostic nutritional index (PNI) <36.2 were associated with reduced OS. Conclusion: ESD was associated with improved OS in patients with clinical T1N0 EGC aged ≥85 years compared with the absence of treatment. Furthermore, CCI and PNI were helpful for patient selection.

Feasibility of endoscopic submucosal dissection for cecal tumors involving the ileocecal valve or appendiceal orifice.

Endoscopic resection of the ileocecal valve lesions (ICVL) and peri-appendiceal orifice lesions (PAOL), is challenging. This study aimed to evaluate the feasibility of endoscopic submucosal dissection (ESD) for ICVLs and PAOLs compared with other cecal lesions (OCEL). This was a multicenter, retrospective cohort study conducted at a cancer center hospital and two community hospitals. Non-pedunculated cecal lesions that were intended to be treated by ESD followed by at least one surveillance colonoscopy were included. The main outcome was curative resection defined as en-bloc resection and R0 resection without risk factors of metastases. The secondary outcome was co lon preservation. A total of 206 patients with 206 cecal lesions, including 37 ICVL, 27 PAOL, and 142 OCEL, who were to be treated with ESD were included in this study. Curative resection rates were 75.7% for ICVL, 70.4% for PAOL, and 77.5% for OCEL (P=0.67). In the multivariate analysis of predictors of curative resection, tumor size (<40mm) (odds ratio [OR] 2.40; 95% confidence intervals [CI], 1.14-5.04; P=0.02) and a negative non-lifting sign (OR 6.12; 95% CI, 2.55-14.60; P<0.01) were significant. Colon preservation was achieved for 91.9% of the ICVL, 92.6% of the PAOL, and 90.8% of the OCEL (P=0.947). Based on curative resection and colon preservation rates, ESD was found to be feasible for ICVL and PAOL. Large tumor size (≥40mm) and positive non-lifting signs were significant factors for non-curative resection.

The safety and feasibility of endoscopic submucosal dissection using a flexible three-dimensional endoscope for early gastric cancer and superficial esophageal cancer: A prospective observational study.

Endoscopic submucosal dissection (ESD) is performed as one of standard treatments for patients with early gastric cancer (EGC) and superficial esophageal squamous cancer (SESCC). A prototype of a flexible endoscope with a 3-D system has been recently developed. This study aimed to investigate the safety and feasibility of ESD using a 3-D flexible endoscope (3-D ESD) for EGC and SESCC. This single-center, prospective, observational study enrolled patients who underwent planned 3-D ESD. The clinical outcomes, including the incidence of adverse events and treatment results, were analyzed. Visibility and manipulation during 3-D ESD were evaluated using a visual analog scale (VAS). We also evaluated the effect of the 3-D system on the endoscopist using VAS and the critical flicker fusion frequency (CFFF). We analyzed 47 EGC and 20 SESCC cases. There are no bleeding cases that required transfusion and perforation during 3-D ESD in both EGC and SESCC patients. However, the incidence of delayed bleeding and delayed perforation was 1.5% (one case) each. The mean VAS scores for recognizing the submucosal layer during the submucosal dissection, visual perception of blood vessel, and depth perception were 72.7±22.2, 74.7±21.8, and 78.2±19.9, respectively. In contrast, the mean VAS score for manipulation was 25.4±19.7. Among endoscopists, there was no significant difference in the VAS of eyestrain and headache before and after ESD, and there was no significant difference in the CFFF. The safety and feasibility of 3-D ESD for EGC and SESCC are acceptable in both patients and endoscopists.

The feasibility of endoscopic submucosal dissection for colorectal lesions larger than 10cm.

Although endoscopic submucosal dissection (ESD) enables en bloc removal of colorectal neoplasms, its effectiveness for larger lesions (≥ 10cm in diameter) is undetermined. We aimed to investigate the feasibility and safety of ESD for colorectal lesions ≥ 10cm wide. This retrospective study included 3591 consecutive colorectal lesions managed with ESD from June 2012 through December 2020. Clinicopathological characteristics and treatment outcomes were compared between lesions ≥ 10cm wide and lesions 5-10cm wide. There were 50 patients in the ≥ 10cm group and 270 patients in the 5-10cm group. Among patients in the ≥ 10cm group, lesions were most often in the rectum (50.0%), and the laterally spreading tumor-granular nodular mixed type (LST-G-M) was most prevalent (41/50, 82%). Although patients in the ≥ 10cm group a longer mean ESD procedure time (186.0 vs. 94.4min, p < 0.001), the dissection speed was significantly higher in this group (0.50 vs. 0.41 cm2/min, p = 0.003). The en bloc and curative resection rates were comparable between the ≥ 10cm and 5-10cm groups (100% vs. 99.6% and 86.0% vs. 88.5%, respectively). Although the stenosis rate was higher in the ≥ 10cm group (4% vs. 0%), the delayed bleeding and perforation rates were similar between the two groups. ESD for colorectal lesions ≥ 10cm wide is feasible and curative, even though it is associated with higher technical difficulty and longer procedure times compared with ESD for smaller lesions (Number: UMIN 000044313).

S467 Indications and Outcomes With Endoscopic Submucosal Dissection for High-Grade Barrett’s Esophagus

Introduction: Barrett’s esophagus (BE) is a known precursor to esophageal dysplasia and adenocarcinoma. First line therapy for BE with dysplasia includes endoscopic mucosal resection (EMR) for raised lesions followed by radiofrequency ablation (RFA) for remaining flat dysplastic tissue. Recently, advancements in the field of endoscopic submucosal dissection (ESD) have expanded this technique to en-bloc resection of dysplastic and early cancerous tissue in the esophagus. Safety and feasibility of ESD have been studied, however, clear indications for this procedure are lacking. We aim to characterize indications for ESD and its outcomes in patients with high-grade BE at our institution. Methods: This was an observational, retrospective cohort study evaluating patients at a tertiary care center who underwent ESD for BE with dysplasia or T1 lesions. We queried the Endoscopy Procedure Documentation system for all ESDs performed at our institution in the esophagus. All patients who underwent ESD for esophageal adenocarcinoma were included; patients with esophageal squamous cell carcinoma were excluded. Chart reviews were conducted to obtain patient demographics at the time of ESD, pathology, including lymphovascular invasion prior to ESD, nodularity at the time of ESD, as well as outcomes and complications after the procedure. Results: 15 patients underwent ESD for high-grade BE. Demographics, pathology and indication for ESD are detailed in Table,2 and 3. 14/15 patients had nodules present and 2/14 had more than 1 nodule. 5/15 had EMR performed prior to ESD; 4/5 had positive margins from the EMR. The most common pathology prior to ESD was T1a (9/15). The most common indication for ESD was nodule size. All procedures were performed successfully, with stricture and bleeding documented as complications. 4/15 patients had positive margins on dissected specimen and surgery was recommended after ESD for 2/15. Conclusion: ESD is a promising technique that has had an increasing role in management of high-grade BE. However, variability in this disease presentation has limited a standardized approach to incorporation of ESD. Our institution’s experience with ESD for high-grade BE indicates that numerous factors exist in consideration of ESD beyond those listed by current best practice guidelines. Gastroenterologists would benefit from a standardized approach to considering ESD in management of high-grade BE.Figure 1.: Demographics and Clinical Characteristics of Patients who Underwent ESD for High-Grade BE

Lymph node metastasis risk factors and applicability of endoscopic submucosal dissection in mixed-type early gastric cancer in Chinese patients.

To analyze the risk factors of lymph node metastasis (LNM) of mixed-type early gastric cancer (EGC), and to explore whether endoscopic submucosal dissection (ESD) is applicable to mixed-type EGC in Chinese patients. A total of 812 EGC patients were included. We classified the lesions into four types: pure moderately differentiated (PMD) adenocarcinoma, mixed predominantly moderately differentiated (MMD) type, mixed predominantly poorly differentiated (MPD) type, and pure poorly differentiated (PPD) adenocarcinoma. LNM risk factors in EGC were evaluated by univariate and multivariate analyses, and the feasibility of ESD in mixed-type EGC was estimated. The LNM rate in mixed-type EGC was 24.7% (68/275). Tumor size [odds ratio (OR) =1.419, P=0.008], MPD (OR =3.278, P=0.002), submucosal invasion ≥500 µm (OR =5.059, P=0.002), and lymphovascular invasion (LVI) (OR =5.836, P<0.001) were independent predictors of LNM in mixed-type EGC. LNM was more common in MMD patients than in PMD patients who met the expanded indications for ESD of differentiated EGC (0.0% vs. 7.84%, P=0.005). Tumor size, histology, invasion depth, and LVI are independent risk factors for LNM in mixed-type EGC. The absolute indications for ESD are applicable to MMD, and the feasibility of the expanded indications for ESD in MMD and MPD requires further investigation in Chinese patients.

Endoscopic Submucosal Dissection Using EndoTrac, a Novel Traction Device

Background: Endoscopic submucosal dissection (ESD) is recognized as a minimally invasive and curative treatment for superficial gastrointestinal (GI) cancers. However, ESD is still challenging and time-consuming with a high risk of adverse events such as bleeding and perforation. Various traction methods have been explored for maintaining good visualization of the submucosal layer during ESD. We developed a novel traction device (the EndoTrac) which can easily tie the thread and has the ability to change the towing direction. The aim of this study is to evaluate safety and feasibility of ESD using the EndoTrac for GI neoplasms. Patients and Methods: We retrospectively analyzed 44 patients (45 lesions) with esophageal, gastric, duodenal, and colorectal neoplasms who had undergone ESD using the EndoTrac device between June 2018 and May 2019. Primary outcome measures were preparation time, procedural success using the EndoTrac device, and ease of ability to change towing direction. Results: Mean preparation time was 2 (2–5) min in esophagus, 3 (1–5) min in stomach, 6 (5–9) min in duodenum, and 4 (2–8) min in colorectum. The procedural success rate was 100% (8/8) in esophagus, 100% (21/21) in stomach, 100% (4/4) in duodenum, and 100% (12/12) in colorectum. The rate of successful towing to both proximal and distal sides was 100% (8/8) in esophagus, 100% (21/21) in stomach, 0% (0/4) in duodenum, and 100% (12/12) in colorectum. Conclusions: Use of the EndoTrac device appears to be a feasible approach to ESD for GI neoplasms.

Feasibility of Endoscopic Submucosal Dissection for Early Esophageal Squamous Cell Carcinoma with Relative Indications

Backgrounds: Endoscopic submucosal dissection (ESD) has been widely performed in the treatment of early esophageal squamous cell carcinoma (ESCC). Few studies have compared the long-term outcomes of esophageal ESD based on absolute indications and relative indications. The aim of the current study was to investigate the safety and efficacy of ESD for early ESCC with relative indications. Methods: 297 patients with early ESCC who underwent ESD were retrospectively analyzed. They were divided into 3 groups: group A, the absolute indications group; group B, the relative indications without additional treatment after ESD group; and group C, the relative indications with additional treatment after ESD group. The baseline characteristics, therapeutic efficacy, complications, prognosis outcomes, and follow-up data were evaluated. Results: During the median follow-up period of 51.0 months (range 6–101 months), the incidence of local recurrence in groups A, B, and C was 1.63% (3/184), 4.23% (3/71), and 0 (0/42), respectively (p = 0.253). The 5-year overall survival rates were 97.83% (95% CI: 95.69–99.95%) in group A, 95.77% (95% CI: 90.95–100.00%) in group B, and 97.62% (95% CI: 92.81–100.00%) in group C with no significant differences among these 3 groups. Conclusions: ESD is a feasible and effective treatment for early ESCC with relative indications. Under the premise of sufficient preoperative assessment and scheduled postoperative endoscopic surveillance, additional treatment might not be necessary for patients with relative indications after ESD procedures.

Endoscopic submucosal dissection and tunneling procedures using a novel all-in-one bipolar device.

Background and study aims Recent innovations in devices and techniques have revolutionized the field of endoscopic resection procedures. In this study, we evaluated the safety and feasibility of endoscopic submucosal dissection and tunneling procedures with a novel, multipurpose bipolar device. Patients and methods Data from consecutive patients who underwent per-oral endoscopic myotomy (POEM), submucosal tunneling endoscopic resection (STER), and endoscopic submucosal dissection (ESD) using a novel bipolar device (December 2019 to February 2020) were analyzed retrospectively. Procedure duration, technical success, and adverse events (AEs) were recorded. Results A total of 10 procedures were performed using the novel bipolar device during the study period. The procedures included POEM (n = 7), STER for esophageal sub-epithelial tumor (n = 1), ESD for rectal polyp (n = 1), and gastric neuroendocrine tumor (n = 1). POEM was successfully completed in all patients. In patients who underwent STER and ESD, en-bloc resection was achieved in all. Mean procedure time for submucosal tunneling procedures (POEM and STER) was 59.12 ± 31.12 minutes. The procedures were completed without the requirement for exchange of accessories in eight cases (80 %). There were no major AEs. Mild and moderate AEs occurred during POEM and included capno-peritoneum (n = 1), retroperitoneal CO 2 (n = 1), and empyema (n = 1). Conclusion ESD and tunneling procedures can be safely performed without the need for exchange of accessories using a novel bipolar device. Randomized comparison with conventional knives isrequired to confirm the utility of this device.

Endoscopic resection of large pedunculated colon polyps using only a scissor-type knife: a case series.

Background and AimsAll pedunculated colon polyps (PCPs) should ideally be resected en bloc for accurate histopathological evaluation. However, maneuvering a snare around the large head of a pedunculated polyp with a long, wide stalk can be technically challenging. In addition, clinically significant bleeding after snare polypectomy remains a legitimate concern. Small case series from Asia have supported the feasibility of endoscopic submucosal dissection (ESD) for the removal of these challenging large PCPs. However, ESD is not widely performed in the West because of its technical complexity, steep learning curve, and higher risk of adverse events when compared with conventional endoscopic mucosal resection. Our aim was to demonstrate the feasibility of performing en bloc resection of large PCPs using a scissor-type electrocautery ESD knife when conventional snare polypectomy is not feasible.MethodsTwo patients were found to have large PCPs with wide stalks. Attempts to maneuver a snare around the head of the PCP were unsuccessful, and the decision was to proceed with ESD using the scissor-type knifeResultsBoth polyps were successfully resected en bloc using only the scissor-type knife. Both procedures were completed in under 20 minutes with no adverse events. Histopathology results of both polyps were consistent with tubulovillous adenoma with resection margins free of dysplasia, consistent with curative R0 resection.ConclusionEn bloc resection of large PCPs can be challenging when it is difficult to maneuver the snare around the head of the polyp. In this video, we demonstrate how a dedicated scissor-type ESD knife can facilitate the resection of these lesions. The insulated rotatable blades of the scissor-type knife allow safe and precise dissection of the stalk under direct visualization, which further permits targeted hemostasis when needed. Future studies are needed to corroborate the efficacy and safety of this device for the resection of selected colorectal lesions.

Efficacy and safety of endoscopic submucosal dissection using a scissors-type knife with prophylactic over-the-scope clip closure for superficial non-ampullary duodenal epithelial tumors.

This study aimed to assess the safety and feasibility of endoscopic submucosal dissection (ESD) using a scissors-type knife with prophylactic closure using over-the-scope clip (OTSC) for superficial non-ampullary duodenal epithelial tumors (SNADETs). Consecutive patients who underwent ESD for SNADETs >10 mm between January 2009 and July 2019 were retrospectively enrolled. We performed ESD using either a needle-type knife (Flush Knife-ESD) or a scissors-type knife (Clutch Cutter-ESD). Mucosal defects were prophylactically closed using three methods: conventional clip, laparoscopic closure, or OTSC. A total of 84 lesions were resected using the Flush Knife-ESD and the Clutch Cutter-ESD (37 and 47 patients, respectively), and conventional clip, laparoscopic closure, and OTSC for mucosal defect closure after ESD were applied in 13, 13, and 56 lesions, respectively. The R0 resection rate was significantly higher in the Clutch Cutter-ESD than that in the Flush Knife-ESD (97.9% vs 83.8%, respectively, P = 0.040). The intraoperative perforation rate was significantly lower in the Clutch Cutter-ESD than in the Flush Knife-ESD (0% vs 13.5%, respectively, P = 0.014). Complete closure rates of conventional clip, laparoscopic closure, and OTSC were 76.9%, 92.3%, and 98.2%, respectively (P = 0.021); and delayed perforation rates were 15.4%, 7.7%, and 1.8%, respectively (P = 0.092). Endoscopic submucosal dissection using a scissors-type knife with prophylactic OTSC closure is safe and feasible for the low-invasive treatment of SNADETs.

Feasibility of endoscopic submucosal dissection for colorectal neoplasia at anastomotic sites: a retrospective study.

Metachronous colorectal lesions sometimes occur at anastomotic sites following colorectal surgery, which increases the risk of developing colorectal cancer. However, these lesions are difficult to treat even with minimally invasive methods such as endoscopic submucosal dissection (ESD). Thus, we aimed to evaluate the outcomes of ESD for colorectal lesions at anastomotic sites following colorectal surgery. We retrospectively investigated 11 patients with post-surgical colorectal lesions at anastomotic sites who later underwent ESD from May 2010 to April 2019 at Keio University Hospital, Tokyo, Japan. We examined the patients' background (tumor location, macroscopic type, tumor size, histological type, and depth of invasion) and treatment outcomes (procedure duration, en bloc resection rate, R0 resection rate, and adverse events). The patients' mean age was 66years. There were two lesions in the transverse colon, six in the rectum, one in the anal canal, and two in the ileal pouch. The median tumor size was 25mm. The macroscopic types were the protruded type (1 lesion) and the flat or depressed type (10 lesions). The pathological diagnoses were adenoma (4 lesions), intramucosal cancer (corresponding to high-grade dysplasia) (6 lesions), and muscularis propria cancer (1 lesion). The median procedure duration was 50min; en bloc resection rate was 88.9% and R0 resection rate was 66.7%. The only adverse event was delayed post-ESD bleeding. A high en bloc resection rate without perforation was achieved with ESD for lesions at anastomotic sites. Although ESD for lesions at anastomotic sites is a technically challenging procedure because of severe submucosal fibrosis, this approach could prevent the need for repeated surgical resection.

Endoscopic submucosal dissection in rectal tumors extending or not to the dentate line: A comparative analysis

BackgroundThe feasibility of endoscopic submucosal dissection (ESD) in rectal tumors extending to the dentate line (RTDL) is unclear. AimsTo analyze the outcomes of ESD in RTDL compared to non-RTDL, with a special focus on the lower rectum location. MethodsObservational multicenter retrospective study. All patients with a rectal tumor who underwent ESD in 2013–2017 were included. A comparative analysis between RTDL and non-RTDL groups was done. ResultsTwo-hundred and twenty-eight patients (median age: 69 years, range: 33–89, 51.3% male) with RTDL (n = 65, 28.5%) and non-RTDL lesions (n = 163, 71.5%) were included. There were no significant differences between the en-bloc (89.2% vs. 90.8%, p = 0.718), complete (60% vs. 71.8%, p = 0.084) and curative resection rates (58.5% vs. 68.7%, p = 0.141). The overall complication rate (4.6% vs. 8%, p = 0.370) was not different, independently of the rectal location. Local recurrence was higher in RTDL (7.3% vs. 1.5%, p = 0.065). The indication for surgery due to non-curative resections in the lower rectum was lower in RTDL (9.2% vs. 14.6%, p = 0.378). ConclusionThe safety, effectiveness and long-term impact of ESD in RTDL and non-RTDLs is comparable. Local recurrence in the lower rectum may be higher in RTDL.

Feasibility of endoscopic submucosal dissection of lesions at anastomosis site post-colorectal surgery: a case series

Background and study aims Patients who have undergone colorectal surgery for resection of cancer and benign lesions are at risk for recurrent, residual, or metachronous lesions at the anastomosis site. Surgical resection of such lesions is difficult because of adhesions, and a stoma may be required as there are risks for leakage after resection. The feasibility and safety of endoscopic submucosal dissection (ESD) for these lesions remain unknown. Therefore, this case series aimed to examine the feasibility and safety of ESD by evaluating the clinical outcomes. Patients and methods We retrospectively investigated five patients who underwent ESD by a single expert for superficial neoplastic lesions at the anastomosis site after previous colorectal surgery. Results R0 resections were achieved for all lesions. Mean procedure time was 160.6 minutes. Mean dimensions of the resected specimen and tumor were 52.4 mm and 31.8mm, respectively. None of the patients had complications or recurrence after surveillance colonoscopy 1-year post-resection. Conclusions In an expert’s hands, ESD at the anastomosis site might be feasible minimally invasive treatment for superficial neoplastic lesions.

Endoscopic submucosal dissection in management of colorectal tumors near or involving a diverticulum: a retrospective case series.

Background and study aims Surgery is the standard treatment for colon tumors associated with diverticulum. U se of endoscopic submucosal dissection (ESD) to treat such tumors is controversial. The aim of this study was to assess the safety and feasibility of ESD in treating superficial colorectal tumors situated near or involving diverticulum. Patients and methods Consecutive patients from two referral centers who had colorectal tumors near or involving diverticulum treated by ESD were retrospectively studied. Clinicopathological characteristics and clinical outcomes were analyzed. Results Of the 12 patients studied, six had tumors near diverticulum and six had tumors involving diverticulum. The overall en-bloc R0 resection rate, median tumor size and procedure time were 67 %, 26.5 mm (range, 15 – 80 mm) and 110 minutes (range, 50 – 220 minutes), respectively. For tumors near diverticulum group, the en-bloc R0 resection rate was 100 % and no adverse events (AEs) or residual/recurrent tumors were observed. In contrast, for intradiverticular tumors group, the en-bloc R0 resection rate was low at 33 %, and one AE (perforation) was observed. The diverticula were ≥ 6 mm in diameter in the patients with incomplete resection. However, all but one diverticulum was unrecognized before ESD. Two residual tumors were detected at the 12-month surveillance and one required surgery. Conclusions This case series indicates that ESD is safe and feasible for treating colorectal tumors near a diverticulum and might be feasible for tumors involving a diverticulum smaller than 6 mm. Selection for smaller diverticulum size may contribute to higher en-bloc R0 resection rates.

Clinical feasibility of endoscopic submucosal dissection with minimum lateral margin of superficial esophageal squamous cell carcinoma.

Background Esophageal stricture following endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell cancer (SESCC) has been associated with wide mucosal defects greater than three-quarters of the luminal circumference. Some patients developed dysphagia and required repeated endoscopic balloon dilation even after steroid therapy. As iodine staining clearly visualized the margin of SESCC, we made a longitudinal mucosal incision close to the margin of the lesion to avoid a mucosal defect involving over three-quarters of the luminal circumference for large lesions. This retrospective study aimed to clarify the clinical feasibility of ESD with minimum lateral margin of SESCC. Patients and methods Between 2005 and 2013, 94 patients with 94 initial SESCCs had lesions greater than half of the luminal circumference. Of those, 70 patients with 70 SESCCs had achieved endoscopic clearance for the initial SESCC. In this study, endoscopic clearance was defined as en bloc resection of SESCC histologically confined to the mucosa without lymphovascular invasion and with a free deep margin regardless of the lateral margin. This study evaluated the short- and long-term outcomes in patients undergoing endoscopic clearance. Results In total, 61.4 % (43/70) of the patients had mucosal defects involving over three-quarters of the luminal circumference and 38.5 % (27/70) had a positive or indeterminate lateral margin. However, there was no local or nodal recurrence during the median follow-up period of 3.8 years; the 3-year overall survival rate was 98.5 % and the 3-year disease-free survival rate was 100 %. Conclusion Using our institutions’ strategy, ESD for SESCCs with minimum lateral margins was oncologically acceptable; this approach could reduce the known risk factor of post-ESD stricture.

Utility of Endoscopic Submucosal Dissection in the Remnant Stomach and Clinical Outcomes for Different Reconstruction Methods

Background: The number of patients with remnant gastric tumor during postoperative follow-up is increasing. We evaluated clinical outcomes to determine the feasibility of endoscopic submucosal dissection (ESD) for early gastric neoplasm in the remnant stomach. Methods: We compared 138 lesions of ESD in the remnant stomach after proximal gastrectomy, distal gastrectomy (DG) or pylorus-preserving DG with 3,237 lesions of ESD in the intact stomach. ESD was performed at our hospital between January 2005 and September 2017. Results: Compared with the intact group, the remnant group had significantly longer mean procedure duration and lower rates of curative resection (all p < 0.01). However, complication rates did not differ significantly between the 2 groups. Among the reconstruction techniques after DG, the rate of lesions at the anastomosis site was significantly higher and the mean procedure duration was significantly longer after Billroth II reconstruction (both p < 0.01). Also, curative resection rate was significantly lower after Billroth II (50.0%) than after Billroth I (p < 0.05). Conclusions: Although technically demanding, ESD for early gastric tumor in the remnant stomach was a safe and effective therapeutic method. However, because the curative resection rate was lower for the more frequent lesions occurring at the anastomosis site after Billroth II reconstruction, early detection of remnant stomach tumor is desirable after Billroth II reconstruction following DG.

Technical feasibility of endoscopic submucosal dissection for local failure after chemoradiotherapy or radiotherapy for esophageal squamous cell carcinoma

Salvage endoscopic submucosal dissection (ESD) after chemoradiotherapy can be technically difficult as a result of radiation-induced fibrosis. We aimed to evaluate the technical feasibility of ESD for local failure after chemoradiotherapy for esophageal squamous cell carcinoma (ESCC) and for other primary lesions within the irradiation field. Consecutive patients treated with ESD for superficial ESCC between December 2009 and May 2017 were investigated retrospectively and stratified into group A (33 patients, 35 lesions; local failure at the primary site after chemoradiotherapy), group B (25 patients, 34 lesions; second primary lesions within the irradiation field), and group C (550 patients, 596 lesions; radiotherapy-naïve superficial ESCC). We evaluated procedural success rate, en bloc resection rate, 1-year local relapse-free survival (LRFS) rate, procedure time, and incidence of major adverse events. The rates of procedural success and en bloc resection, respectively, were significantly lower in group A (89%, 86%) than in groups B (100%, 100%) and C (100%, 98%). The 1-year LRFS rates were 86%, 100%, and 99% in groups A, B, and C, respectively, and significantly lower in group A than in group C. Serious adverse events including perforation were not observed in groups A and B; perforation occurred only in group C (2.8%). ESD is technically feasible in patients with local failure, especially as initial salvage treatment and as treatment for second primary lesions within the irradiation field.

111 EFFICACY AND SAFETY OF ENDOSCOPIC SUBMUCOSAL DISSECTION WITH OVER-THE-SCOPE-CLIP CLOSURE FOR SUPERFICIAL NON-AMPULLARY DUODENAL EPITHELIAL TUMOR

Endoscopic treatment such as endoscopic submucosal dissection (ESD) for superficial non-ampullary duodenal epithelial tumor (SNADET) is often caused high rate of delayed complications. We reported that laparoscopic and endoscopic co-operative surgery (LECS) is one of the minimally invasive treatments for SNADET. LECS can prevent delayed complications due to laparoscopic closure. In contrast, there have been some reports with regard to the usefulness of the over-the-scope clip (OTSC) for prevention of delayed complications after endoscopic treatment. The aim of this study was to assess the safety and feasibility of ESD with OTSC closure for SNADET compared with LECS. The patients who underwent ESD with OTSC closure (ESD-OTSC) and LECS at the hospital of Kyoto Prefectural University of Medicine were enrolled between 2015 and 2017. The indication for these procedures was the presence of SNADETs with a low risk for lymph node metastasis. In particular, the tumors included epithelial mucosal tumors, such as mucosal cancers or large mucosal adenomas with malignant suspicion. The LECS procedure is laparoscopic reinforcement after ESD for SNADETs. The primary endpoint was the rate of en block resection, delayed complications (perforation and bleeding), and residual tumor 3 months after the resection. All patients provided written informed consent. This study was approved by the ethical committee of Kyoto Prefectural University of Medicine. A total of 11 and 22 lesions in 10 and 21 patients (male/female 5/5:12/9, median age 71:63 years) were resected by LECS and ESD-OTSC between 2015 and 2017, respectively. In LECS and ESD-OTSC cases, lesion’s location was first/2nd/third portion 2/8/1 and 4/18/0, median lesion’s size was 23.6 and 16.2mm (range 7-40 and 12-24), and macroscopic type was elevated type/ depressed type 10/1 and 16/6, respectively, with no significant difference. Median tumor size in LECS and ESD-OTSC cases was 14.5 and 23.7 mm (range 7-40 and 13-38 mm), and the rate of R0 resection was 81.8 and 95.5%, respectively, with no significant difference. Median procedure time in ESD-OTSC cases was significantly shorter than that in LECS cases (47 min, range 15-135 min and 104 min, range 20-225 min, respectively, P< 0.01). No delayed complications (bleeding and perforation) were also observed in all cases. Histopathological diagnosis (adenoma/ T1a cancer/ T1b cancer) in LECS and ESD-OTSC cases revealed 1/9/1 and 1/19/2, respectively. No local recurrence was detected endoscopically in all cases 2 months later. ESD with OTSC closure for SNADET could be a safe procedure with a shorter procedure time compared to LECS.