• Clinical Endoscopy
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• v.55 no.5
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• pp.655-664
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• 2022

Background/Aims: Endoscopic submucosal dissection (ESD) for residual or recurrent colorectal lesions after incomplete resection is challenging because of severe fibrosis. This study aimed to compare the efficacy of the pocket-creation method (PCM) with a traction device (TD) with that of conventional ESD for residual or recurrent colorectal lesions. Methods: We retrospectively studied 72 patients with residual or recurrent colorectal lesions resected using ESD. Overall, 31 and 41 lesions were resected using PCM with TD and conventional ESD methods, respectively. We compared patient background and treatment outcomes between the PCM with TD and conventional ESD groups, respectively. The primary endpoints were en bloc resection and R0 resection rates. The secondary endpoints were the dissection speed and incidence of adverse events. Results: En bloc resection was feasible in all cases with PCM with TD, but failed in 22% of cases of conventional ESD. The R0 resection rates for PCM with TD and conventional ESD were 97% and 66%, respectively. Dissection was significantly faster in the PCM with TD group (13.0 vs. 7.9 mm²/min). Perforation and postoperative bleeding were observed in one patient in each group. Conclusions: PCM with TD is an effective method for treating residual or recurrent colorectal lesions after incomplete resection.

• Journal of Gastric Cancer
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• v.11 no.3
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• pp.155-161
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• 2011

Purpose: To determine the diagnostic utility of a frozen section biopsy in patients undergoing endoscopic submucosal dissection (ESD) for early gastric neoplasms with obscure margins even with chromoendoscopy using acetic acid and indigo carmine (AI chromoendoscopy). Materials and Methods: The lateral spread of early gastric neoplasms was unclear even following AI chromoendoscopy in 38 patients who underwent ESD between June 2007 and May 2011. Frozen section biopsies were obtained by agreement of the degree of lateral spread between two endoscopists. Thus, frozen section biopsies were obtained from 23 patients (FBx group) and not in the other 15 patients (AI group). Results: No significant differences were observed for size, histology, invasive depth, and location of lesions between the AI and FBx groups. No false positive or false negative results were observed in the frozen section diagnoses. Adenocarcinoma was revealed in three patients and tubular adenoma in one, thereby changing the delineation of lesion extent and achieving free lateral margins. The rates of free lateral resection margins and curative resection were significantly higher in the FBx group than those in the AI group. Conclusions: Frozen section biopsy can help endoscopists perform more safe and accurate ESD in patients with early gastric neoplasm.

• Journal of Gastric Cancer
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• v.23 no.3
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• pp.451-461
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• 2023

Purpose: Endoscopic submucosal dissection (ESD) is an effective treatment for early gastrointestinal neoplasms. However, this is a time-consuming procedure requiring various devices. This study aimed to evaluate the efficacy and safety of the ClearCut^TM Knife H-type, which is an integrated needle-tipped and insulated-tipped (IT) knife. Materials and Methods: Between July 2020 and September 2021, 99 patients with gastric epithelial neoplasms scheduled for ESD at three tertiary care hospitals were randomly assigned to H-knife (ClearCut^TM Knife H-type) or IT-knife (conventional IT knife) groups. Procedure times, therapeutic outcomes, and adverse events were analyzed. Results: A total of 98 patients (50 in the H-knife group and 48 in the IT-knife group) were analyzed. The median total procedure time was 11.9 minutes (range, 4.4-47.2 minutes) in the H-knife group and 12.7 minutes (range, 5.2-137.7 minutes) in the IT-knife group (P=0.209). Unlike the IT-knife group, which required additional devices in all cases, no additional devices were used in the H-knife group (P<0.001). En-bloc resection was performed for all lesions in both groups. The incidence of adverse events was not significantly different between groups (4.0% in the H-knife group vs. 8.3% in the IT-knife group; P=0.431). Conclusions: The newly developed hybrid device, the ClearCut^TM Knife H-type, had comparable efficacy to the conventional IT knife for gastric ESD.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8917-8921
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• 2014

Objective: To observe and compare the effects of multi-patch biopsy under conventional white light imaging endoscopy (C-WLI) and precise targeted biopsy under magnifying narrow-band imaging endoscopy (M-NBI) on the endoscopic submucosal dissection (ESD) of early gastric cancers and intraepithelial neoplasias. Methods: According to the way of selecting biopsy specimens, patients were divided into C-WLI and M-NBI groups, 20 cases. The ESD operations of the 2 groups were compared quantitively. Results: The mean frequency of biopsy in M-NBI group was ($1.00{\pm}0.00$), obviously lower than in the C-WLI group ($4.78{\pm}1.02$) (P<0.01).The average total number of selected biopsy specimens was also fewer ($1.45{\pm}0.12$ and $7.82{\pm}2.22$, respectively, P<0.01). There was no significant difference in the time of determining excision extension, marking time and the time of specimen excision of 2 groups during the ESD (P>0.05), whereas submucosal injection time, mucosal dissection time, stopping bleeding time, wound processing time in the M-NBI group were significantly shorter than in the C-WLI group (P<0.01). Conclusion: Precise targeted biopsy under M-NBI can obviously shorten the time of ESD operation, with small quantity of tissues but high pathological positive rate.

• Journal of Gastric Cancer
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• v.20 no.2
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• pp.165-175
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• 2020

Purpose: The guidelines for pathological evaluation of early gastric cancer (EGC) recommend wider section intervals for surgical specimens (5-7 mm) than those for endoscopically resected specimens (2-3 mm). Studies in surgically resected EGC specimens showed not negligible lymph node metastasis risks in EGCs meeting the expanded criteria for endoscopic submucosal dissection (ESD). Materials and Methods: This retrospective study included 401 EGC lesions with an endoscopic size of ≤ 30 mm detected in 386 patients. Pathological specimens obtained by ESD or surgery were cut into 2-mm section intervals for reference. Submucosal or lymphovascular invasion (LVI) was evaluated arbitrarily in 4- or 6-mm section intervals. McNemar's tests compared the differences between submucosal and LVI. Results: Submucosal invasion was detected in 29.2% (117/401) and LVI in 9.5% (38/401) at 2-mm interval. The submucosal invasion detection rates in 4-mm intervals decreased to 88.0% or 90.6% (both P<0.001), while the LVI detection rates decreased to 86.8% or 57.9% (P=0.025 and P<0.001, respectively). In 6-mm intervals, the submucosal and LVI detection rates decreased further to 72.7-80.3% (P<0.001 for all three sets) and 55.3-63.2% (P<0.001 for all three sets), respectively. Among 150 out-of-indication cases at 2-mm interval, 4-10 (2.7%-6.7%) at 4-mm intervals, and 10-17 (6.7%-11.3%) at 6-mm intervals were misclassified as lesions meeting the curative resection criteria due to the underestimation of submucosal or LVI. Conclusions: After ESD, the 2-mm wide section interval was suitable for the pathological evaluation of focal submucosal or LVI. Thus, if an EGC lesion meets the expanded criteria for the ESD specimen pathological evaluation, it could be safely followed up.

• Clinical Endoscopy
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• v.55 no.6
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• pp.760-766
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• 2022

Background/Aims: Endoscopic submucosal dissection (ESD) is an effective method for resecting gastric adenomas and adenocarcinomas. A significant discrepancy was observed between endoscopic and pathological sizes in samples obtained from patients undergoing ESD. This study elucidates the factors affecting size discrepancy after formalin fixation. Methods: The records of 64 patients with 69 lesions were analyzed, including 50 adenomas and 19 adenocarcinomas. Data on location, gross shape, histology, and size after fixation in formalin were collected. Results: The mean size of the resected specimen appeared to decrease after formalin fixation (37.5 mm prefixation vs. 35.8 mm postfixation, p<0.05). The mean long axis diameter of the lesions was 20.3±7.9 mm prefixation and 13.4±7.9 mm postfixation. Size differences in lesions smaller than 20 mm were significantly greater than those in lesions larger than 20 mm (7.6±5.6 mm vs. 2.5±5.8 mm, p<0.01). In multivariate analysis, a tumor size of ≥20 mm was found to be an independent factor affecting size postformalin fixation (p<0.05). Conclusions: The endoscopic size of lesions before ESD may be underestimated in tumors larger than 20 mm in size. Therefore, increased attention must be paid during ESD to avoid instances of incomplete resection.

• Journal of Gastric Cancer
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• v.10 no.3
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• pp.87-90
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• 2010

Early gastric cancer (EGC) is defined as tumor invasion confined to the mucosa or submucosa, regardless of the presence of regional lymph node metastasis. Lymph node metastasis is the most powerful and important prognostic factor for gastric cancer. Based on the risk of lymph node metastasis in EGC obtained from a large number of surgical cases in Japan, it was suggested that the criteria for endoscopic mucosal resection (EMR) and endoscopic submucosal resection (ESD) as local treatment for EGC might be extended. However, extending the indications for EMR and ESD remains controversial because the long-term outcomes of these procedures have not been fully documented, and there is a risk for lymph node metastasis. Furthermore, current diagnostic imaging techniques are unsatisfactory for accurately predicting metastasis to lymph nodes. Moreover, the long-term results of standard radical gastrectomy including minimally invasive procedures for stage IA have been increasing and have reached 99 to 100%. To determine the true efficacy of endoscopic resection of EGC, we need more evidence of long-term follow-up, standardization of techniques, and pathological interpretation.

• Clinical Endoscopy
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• v.55 no.6
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• pp.767-774
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• 2022

Background/Aims: Few studies have compared the performances of endoscopic knives. This study aimed to compare the therapeutic outcomes of a novel core knife and the conventional IT knife 2 for endoscopic submucosal dissection (ESD) of gastric mucosal lesions. Methods: This prospective, non-inferiority trial included patients diagnosed with gastric adenoma or early-stage adenocarcinoma at Keimyung University Dongsan Hospital between June and November 2020. The patients were randomly assigned to either the core knife or the IT knife 2 group. The operators and assistants scored the knives' grip convenience and cutting abilities. Results: A total of 39 patients were enrolled (core knife group, 20 patients; IT knife 2 group, 19 patients). There were no significant between-group differences in operator-assessed grip convenience (9.600 vs. 9.526, p=0.753), cutting ability (9.600 vs. 9.105, p=0.158), or assistant-assessed grip convenience (9.500 vs. 9.368, p=0.574). Conclusions: The core knife achieved therapeutic outcomes that were comparable to those of the IT knife 2 for ESD of gastric mucosal lesions.

• Clinical Endoscopy
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• v.55 no.1
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• pp.15-21
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• 2022

Endoscopic submucosal dissection (ESD) is the standard treatment method for esophageal, gastric, and colorectal cancers. However, it has not been standardized for duodenal lesions because of its high complication rates. Recently, minimally invasive and simple methods such as cold snare polypectomy and underwater endoscopic mucosal resection have been utilized more for superficial nonampullary duodenal epithelial tumors (SNADETs). Although the rate of complications associated with duodenal ESD has been gradually decreasing because of technical advancements, performing ESD for all SNADETs is unnecessary. As such, the appropriate treatment plan for SNADETs should be chosen according to the lesion type, patient condition, and endoscopist's skill.

• Journal of Gastric Cancer
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• v.17 no.1
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• pp.33-42
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• 2017

Purpose: Endoscopic submucosal dissection (ESD) in early gastric cancer causes an artificial gastric ulcer and local inflammation that has a negative intraprocedural impact on additional laparoscopic gastrectomy in patients with noncurative ESD. In this study, we analyzed the effect of ESD on short-term surgical outcomes and evaluated the risk factors. Materials and Methods: From January 2003 to January 2013, 1,704 patients of the National Cancer Center underwent laparoscopic gastrectomy with lymph node dissection because of preoperative stage Ia or Ib gastric cancer. They were divided into 2 groups: (1) with preoperative ESD or (2) without preoperative ESD. Clinicopathologic factors and short-term surgical outcomes were retrospectively evaluated along with risk factors such as preoperative ESD. Results: Several characteristics differed between patients who underwent ESD-surgery (n=199) or surgery alone (n=1,505). The mean interval from the ESD procedure to the operation was 43.03 days. Estimated blood loss, open conversion rate, mean operation time, and length of hospital stay were not different between the 2 groups. Postoperative complications occurred in 23 patients (11.56%) in the ESD-surgery group and in 189 patients (12.56%) in the surgery-only group, and 3 deaths occurred among patients with complications (1 patient [ESD-surgery group] vs. 2 patients [surgery-only group]; P=0.688). A history of ESD was not significantly associated with postoperative complications (P=0.688). Multivariate analysis showed that male sex (P=0.008) and laparoscopic total or proximal gastrectomy (P=0.000) were independently associated with postoperative complications. Conclusions: ESD did not affect short-term surgical outcomes during and after an additional laparoscopic gastrectomy.