Superficial Gastric Lesions Research Articles

A prospective randomized trial comparing the pocket-creation method and conventional method of endoscopic submucosal dissection in early gastric cancers and precancerous lesions

BackgroundEndoscopic submucosal dissection (ESD) is widely used as a standard treatment regimen for early gastric cancers (EGCs). However, such an approach is time consuming and has a high risk of perforation and bleeding in some corner-site lesions because of the obscured view and difficulty in submucosal lifting. The newly developed pocket-creation method (PCM) provides a clearer view and better traction of the submucosal layer than conventional ESD (c-ESD). Nevertheless, no prospective randomized study has evaluated the efficacy of the PCM in EGCs and precancerous lesions. MethodsThis was a prospective randomized controlled trial. Patients with superficial gastric neoplastic lesions ≥ 20 mm were randomly assigned to the PCM-ESD group or c-ESD group. The primary outcome was dissection speed. ResultsThere were 28 patients in the PCM-ESD group and 27 in the c-ESD group. The median dissection speed was significantly higher in the PCM-ESD group than in the c-ESD group (21.5 mm2/min vs 14.3 mm2/min, P < .001). Meanwhile, the operation time in the PCM-ESD group was significantly shorter than that in the c-ESD group (30 vs 40 min, P = .047). In multiple linear regression analysis, the treatment method was independently associated with the resection speed of ESD. ConclusionPCM-ESD was an effective and safe treatment for EGCs and precancerous lesions.

Comparison of Endoscopic Submucosal Dissection With Endoscopic Mucosal Resection After Circumferential Precutting to Treat Gastric Adenomas ≤15 mm

Objectives: Endoscopic submucosal dissection (ESD) is a widely used approach for the resection of superficial gastric neoplastic lesions. Endoscopic mucosal resection (EMR) is acceptable for lesions &lt;10–15 mm in size. Herein, we compared the clinical outcomes of ESD with those of EMR after circumferential precutting (EMR-P) for gastric adenomas ≤15 mm.Methods: We retrospectively analyzed the data of 213 patients with 228 gastric adenomas ≤15 mm in size who were treated endoscopically at a single tertiary hospital in Korea between November 2018 and October 2022. We evaluated the complete endoscopic resection rate, recurrence rate, procedurer-elated complications, and procedure time according to the procedure used.Results: Among the 228 gastric adenomas, 49 were treated with EMR-P and 179 with ESD. The histological complete resection rate was higher in the ESD group than in the EMR-P group (87% vs. 57%, &lt;i&gt;p&lt;/i&gt;&lt;0.001). No significant between-group differences were observed in endoscopic en bloc resection rates (ESD vs. EMR-P, 96% vs. 90%; &lt;i&gt;p&lt;/i&gt;=0.081). The procedure time was significantly shorter in the EMR-P group than in the ESD group (28.9±19.7 min vs. 8.8±5.9 min, &lt;i&gt;p&lt;/i&gt;&lt;0.001). The local recurrence rate in patients with histologically incomplete resection did not differ between the two groups (ESD vs. EMR-P, 8.7% vs. 9.5%; &lt;i&gt;p&lt;/i&gt;=0.924).Conclusions: For gastric adenomas ≤15 mm, EMR-P may be the preferable treatment method considering the en bloc resection rate, procedure time, and local recurrence rate. However, considering the complete resection rate, ESD is recommended as the treatment of choice for high-grade adenomas and early gastric cancer lesions.

Interobserver Reliability of the Paris Classification for Superficial Gastrointestinal Tract Neoplasms: A Systematic Review.

The Paris classification characterizes the morphology of superficial gastrointestinal tract neoplasms. This system has been shown to predict the risk of submucosal invasion in certain subtypes of lesions. There is limited data that assesses its agreement amongst endoscopists. We performed a systematic review to summarize the available literature on the interobserver reliability (IOR) of the Paris classification. We conducted a search through December 2020 for studies reporting IOR of the Paris classification. Studies were included if they quantitatively evaluated the IOR of the Paris classification with at least five participating endoscopists. Two authors independently screened studies and abstracted data using an a priori-designed data collection form. Evaluation of study quality and risk of bias was performed using an adapted version of the Guidelines for Reporting Reliability and Agreement Studies. Of the 1,541 studies retrieved, 5 were included in the review. All studies were observational cohort studies published between 2014 and 2020. The IOR of the Paris classification was moderate amongst all four studies evaluating colorectal neoplasms (range, κ = 0.42 to κ = 0.54) and substantial in one study that evaluated gastric neoplasms (κw = 0.65). An educational intervention was conducted by three studies with variable methodology and no significant change in IOR. IOR of the Paris classification is moderate for superficial colonic neoplasms. Further study is needed to determine the reliability of this system for superficial gastric lesions. Standardized training programs are required to investigate the impact of educational intervention on the Paris classification amongst endoscopists.

Confusion and prospects for carcinogenesis of gastric adenoma and dysplasia: What is the correct answer currently?

There are differences in the diagnoses of superficial gastric lesions between Japan and other countries. In Japan, superficial gastric lesions are classified as adenoma or cancer. Conversely, outside Japan, the same lesion is classified as low-grade dysplasia (LGD), high-grade dysplasia, or invasive neoplasia. Gastric carcinogenesis occurs mostly de novo, and the adenoma-carcinoma sequence does not appear to be the main pathway of carcinogenesis. Superficial gastric tumors can be roughly divided into the APC mutation type and the TP53 mutation type, which are mutually exclusive. APC-type tumors have low malignancy and develop into LGD, whereas TP53-type tumors have high malignancy and are considered cancerous even if small. For lesions diagnosed as category 3 or 4 in the Vienna classification, it is desirable to perform complete en bloc resection by endoscopic submucosal dissection followed by staging. If there is lymphovascular or submucosal invasion after mucosal resection, additional surgical treatment of gastrectomy with lymph node dissection is required. In such cases, function-preserving curative gastrectomy guided by sentinel lymph node biopsy may be a good alternative.

The Pocket-Creation Method Facilitates Endoscopic Submucosal Dissection of Gastric Neoplasms Along the Lesser Curvature at the Gastric Angle.

BackgroundEndoscopic submucosal dissection (ESD) of superficial gastric lesions located along the lesser curvature at the gastric angle is a challenging situation due to paradoxical movement and a protruding angle. The pocket-creation method (PCM) can overcome this difficulty by stabilizing the tip of the endoscope in the pocket and minimizing insufflation of the stomach, which enables horizontal and straight dissection. This study aims to clarify whether the PCM improves the technical outcomes of ESD of superficial gastric neoplasms along the lesser curvature at the angle.MethodsFrom October 2006 to June 2021, 158 gastric lesions along the lesser curvature at the angle were resected with needle-type knives. We retrospectively reviewed the records and divided them into the PCM group (n = 61) and the conventional method (CM) group (n = 97). The primary outcome measurement was dissection speed (in mm2/min).ResultsThe two groups were not significantly different for baseline characteristics such as macroscopic type and size except for the proportion of adenomas. The proportion of expert endoscopists was not significantly different between the two groups (P = 0.141). The dissection speed was significantly faster in the PCM group than in the CM group (P = 0.001). There were no holes in the resected specimens in the PCM group, while five lesions in the CM group (5%) had a hole (P = 0.182). There were no significant differences in the incidence of adverse events.ConclusionsThis is the first study to show that the PCM outperforms the CM for ESD of lesions located along the lesser curvature at the gastric angle. The PCM facilitated ESD of these lesions by significantly increasing dissection speed when a needle-type knife is used with no increase in adverse events.

Multipolar traction with homemade "spider" device to improve submucosal dissection of gastric superficial lesions is safe and effective.

Multipolar traction with homemade "spider" device to improve submucosal dissection of gastric superficial lesions is safe and effective.

The pocket-creation method facilitates endoscopic submucosal dissection of gastric neoplasms involving the pyloric ring.

Background and study aims Endoscopic submucosal dissection (ESD) of superficial gastric lesions involving the pyloric ring is difficult. The pocket-creation method (PCM) with a small-caliber-tip transparent hood can overcome this difficulty by compressing the pyloric sphincter applying both traction and counter-traction. The aim of this study is to clarify the usefulness of the PCM for ESD of superficial gastric neoplasms involving the pyloric ring compared to the conventional method (CM). Patients and methods From October 2006 to August 2019, 66 gastric lesions requiring duodenal submucosal dissection beyond the pyloric ring in 66 patients were resected. The CM was mainly performed in the first period (CM group, n = 46) and the PCM in the second period (PCM group, n = 20). We retrospectively reviewed their medical records. Results Although no significant differences were observed in en bloc resection rates between the two groups, the PCM group had a significantly higher R0 resection rate than the CM group ( P = 0.047). There were no holes in resected specimens in the PCM group while three specimens in the CM group had a hole. The dissection speed in the PCM group tended to be higher than in the CM group, although it did not reach statistical significance ( P = 0.148). No significant differences were observed for the incidence of adverse events. Conclusions This is the first study reporting the advantages of the PCM over the CM for ESD of gastric lesions involving the pyloric ring. We believe that the PCM is an effective strategy to compress the pyloric sphincter and facilitates R0 resection.

Résultats de la résection intra-gastrique laparoscopique

BackgroundTechnological and operative advancements have allowed laparoscopic intragastric surgery (LIGS) to be applied in the treatment of superficial gastric or submucosal lesions. The aim of this study was to evaluate short- and long-term outcomes following LIGS. MethodsFrom 2000 to 2013, 25 LIGSs were performed for superficial gastric lesions. Clinical records were reviewed retrospectively for perioperative course and long-term outcomes with particular attention to the oncological follow-up for patients with malignant lesions. ResultsNineteen (76 %) lesions were located close to the EGJ, three (12 %) in the lesser curvature, two (8 %) in the posterior wall and one (4 %) in the prepyloric antral region. A multiport technique was used in 15 (60 %) patients and a single access approach in 10 (40 %) patients. The median operative time was 140 (50–210) minutes. No conversion to open or conventional laparoscopic surgery was needed. Mortality was nil, and severe morbidity occurred in one (4 %) patient. The median length of stay was 6 (3–10) days. Indications of LIGS were adenocarcinoma in 11 (44 %) patients, gastrointestinal stromal tumors (GISTs) in 6 (24 %) patients and benign lesions in eight (32 %) patients. En bloc resection was obtained in 24 (96 %) patients with R0 margins in 23 (92 %) patients. After a median follow-up of 76 (26–171) months, recurrence was detected in 4 (36 %) patients with advanced malignant adenocarcinoma. ConclusionLIGS provides an interesting alternative to major gastric and EGJ resection when endoscopic resection is not suitable for highly selected patients with superficial gastric lesions.

Results of laparoscopic intragastric surgery.

Technological and operative advancements have allowed laparoscopic intragastric surgery (LIGS) to be applied in the treatment of superficial gastric or submucosal lesions. The aim of this study was to evaluate short- and long-term outcomes following LIGS. From 2000 to 2013, 25 LIGSs were performed for superficial gastric lesions. Clinical records were reviewed retrospectively for peri-operative course and long-term outcomes with particular attention to the oncological follow-up for patients with malignant lesions. Nineteen (76%) lesions were located close to the EGJ, three (12%) in the lesser curvature, two (8%) in the posterior wall and one (4%) in the prepyloric-antral region. A multiport technique was used in 15 (60%) patients and a single-access approach in 10 (40%) patients. The median operative time was 140 (50-210) minutes. No conversion to open or conventional laparoscopic surgery was needed. Mortality was nil, and severe morbidity occurred in one (4%) patient. The median length of stay was 6 (3-10) days. Indications of LIGS were adenocarcinoma in 11 (44%) patients, gastrointestinal stromal tumors (GISTs) in 6 (24%) patients and benign lesions in eight (32%) patients. En bloc resection was obtained in 24 (96%) patients with R0 margins in 23 (92%) patients. After a median follow-up of 76 (26-171) months, recurrence was detected in 4 (36%) patients with advanced malignant adenocarcinoma. LIGS provides an interesting alternative to major gastric and EGJ resection when endoscopic resection is not suitable for highly selected patients with superficial gastric lesions.

Efficacy and safety of endoscopic submucosal tunnel dissection vs endoscopic submucosal dissection for early superficial upper gastrointestinal precancerous lesions and tumors: A meta-analysis.

Endoscopic submucosal tunnel dissection (ESTD) is a new treatment for superficial upper gastrointestinal precancerous lesions and tumors. However, its safety and efficacy for treating these lesions is still uncertain. This meta-analysis aimed to compare the efficacy and safety of ESTD with those of endoscopic submucosal dissection (ESD) in treating early superficial upper gastrointestinal precancerous lesions and tumors. Electronic databases, including EMBASE, PubMed, Cochrane Library and the Web of Science, were systematically searched for articles published up to 1 April 2020. The primary outcomes were complete and en bloc resection rates of the lesions. The secondary outcomes included operation time, speed of dissection, complication and recurrence rates. The Newcastle-Ottawa quality assessment scale was used to evaluate the quality of the studies. Seven studies were included in the final meta-analysis. The complete and en bloc resection rates of early superficial esophageal lesions as well as the en bloc resection rate of early superficial gastric lesions were similar between the ESTD and ESD groups. Compared with the ESD group, the ESTD group had a higher en bloc resection rate for early superficial gastric lesions. A faster dissection speed was observed in both superficial esophageal and gastric lesions. In gastric lesions, the operation time of the ESTD group was shorter than that of the ESD group, while it did not differ for esophageal lesions. There were no obvious differences in bleeding and perforation rates between the groups. As an endoscopic technique for treating early superficial upper gastrointestinal lesions, ESTD is as safe as and more effective than ESD, especially for gastric lesions.

Predictors for operation time of endoscopic submucosal dissection for superficial gastric lesions

Objective To investigate the risk factors of operation time of endoscopic submucosal dissection (ESD) for superficial gastric lesions. Methods Clinicopathologic data of 193 patients (195 lesions) diagnosed with early gastric cancer preoperatively who received ESD in Beijing Friendship Hospital from January 2015 to December 2017 were retrospectively collected, including basic information (age, gender, body mass index, comorbidities), lesion characteristics (size, location, morphology), the operators′ experience of ESD, operation time, and postoperative pathology, etc. Univariate analysis was performed to find the risk factors of ESD operation time, and logistic regression analysis was performed on the factors with statistical differences in univariate analysis to find the independent risk factors of ESD operation time over 120 min. Results The mean age of the patients was 63.34±9.11 years. The median time of ESD operation was 120.00 (95.00, 165.00) min and the median size of the lesions was 1.50 (1.00, 2.38) cm. Early gastric cancer was diagnosed by postoperative pathology in 164 lesions (84.10%), among which 162 lesions (98.78%) achieved en bloc resection, and 148 lesions (90.24%) achieved curative resection. The gender (P=0.018), location(P 0.05). Multivariate analysis showed that the lesion located in cardia/fundus of stomach (OR=5.656, 95%CI: 2.291-13.964, P 2 cm in size (OR=2.761, 95%CI: 1.229-6.205, P=0.014) were independent risk factors for the operation time longer than 120 min. Conclusion Lesions located in the cardia/fundus, body of stomach and >2 cm in size are independent risk factors for long operation time of ESD. Key words: Risk factors; Stomach neoplasms; Superficial gastric lesions; Endoscopic submucosal dissection; Operation time

Reliability of Paris Classification for superficial neoplastic gastric lesions improves with training and narrow band imaging.

Background and study aims Paris Classification is used to classify gastrointestinal superficial neoplastic lesions and to predict presence of submucosal invasion. We aimed to evaluate interobserver reliability and agreement for this classification among Western endoscopists. Methods A total of 54 superficial gastric lesions were independently classified according to Paris classification by eight endoscopists (4 experts and 4 non-experts). Observers were asked to classify two sets of images – first, obtained with high-resolution white light (HR-WL) endoscopy and secondly, with the same HR-WL images paired with images obtained with high-resolution Narrow Band Imaging (HR-NBI) – HR-WL + NBI image group. Results Overall interobserver reliability when asked to classify in I, II or III was good both using HR-WL images and HR-WL + NBI images (wK of 0.65 and 0.70, respectively). The proportion of agreement for type III lesions was 0.48 for HR-WL images increasing to 0.74 in the HR-WL + NBI group. Interobserver reliability for identification of a IIc component was only moderate (wK 0,47). NBI improves both sensitivity and interobserver reliability among trainees (from wK 0.19 to 0.47). Specificity was higher than sensitivity in predicting submucosal invasion. Conclusion Overall, the reliability of Paris classification is moderate to good. Training on this classification or its revision and use of technology such as NBI may improve not only reliability and agreement but also accuracy.

Diagnosis of Superficial Gastric Lesions Together with Six Gastric Lymphoma Cases via Probe-Based Confocal Laser Endomicroscopy: A Retrospective Observational Study.

Objective To evaluate the performance of probe-based confocal laser endomicroscopy (pCLE) in diagnosis of gastric lesions. Methods An outpatient department- (OPD-) based retrospective study was conducted for patients with suspected upper gastrointestinal (GI) tract lesions who underwent pCLE between 2014 and 2016 at a tertiary hospital in China. Final diagnosis was based on the histopathological reports. CLE reports were compared to histopathological reports to evaluate the diagnostic ability, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy. Results 322 of 380 patients were diagnosed with gastric lesions via pCLE, including inflammation and benign ulcers (n = 110), atrophy and intestinal metaplasia (n = 152), intraepithelial neoplasia (n = 27), adenocarcinoma (n = 27), and lymphoma (n = 6). In total, the diagnostic ability of CLE in evaluation of gastric lesions showed sensitivity 72.4% (95% confidence interval (CI): 67.1–77.2%); specificity 93.1% (95% CI: 5.6–8.4%); PPV 72.4% (95% CI: 67.1–77.2%); NPV 93.1% (95% CI: 5.6–8.4%); and accuracy 88.9% (95% CI: 87.3–90.4%), respectively. We further observed the capability of pCLE in diagnosing six gastric lymphoma showing those affected mucosa densely infiltrated with identical and round-shaped abnormal cells. Immunohistochemistry analysis confirmed one patient with diffuse large B-cell non-Hodgkin's lymphoma (DLBCL) and five with mucosa-associated lymphoid tissue (MALT) lymphoma. Conclusion pCLE is an accurate tool for the detection of gastric lesions and shows optimal values of sensitivity and negative predictivity. Moreover, combining pCLE with white light endoscopy (WLE) may be a promising adjunct to conventional biopsy sampling in evaluating GI tract with suspected lymphoma.

Endoscopic submucosal dissection of gastric superficial neoplastic lesions: a single Western center experience.

Endoscopic submucosal dissection (ESD) allows "en bloc" resection of superficial gastric lesions. The aim of this study is to report "en bloc" resection rate, procedure results, post resection features, analysis of complications, and relapses at mid-long term follow-up on an Italian center case series of patients with superficial gastric neoplastic lesions treated with ESD. This is a retrospective evaluation of a prospectively collected series of patients diagnosed with gastric superficial lesions who underwent ESD between November 2007 and May 2015. The analysis included demographic, clinical, endoscopic, and histological data. In detail, the following features were analyzed: (1) "en bloc" resection rate; (2) R0, R1, and RX rate; (3) complication rate; and (4) neoplastic recurrence during follow-up. A comparison was performed between lesions treated according to standard and to extended criteria. In the analysis, therefore, 70 superficial lesions and 70 endoscopic procedures were considered.Overall, 53 (76%) procedures were performed according to the extended-ESD criteria. The remaining 17 (24%) cases were performed according to standard criteria. In 68/70 (97%) procedures "en bloc" resection was successful. Forty-four (65.6%) patients had a R0 resection, while 15 (22%) patients had a R1 and the remaining 8 (12.4%) patients were RX. Two patients (2.8%) experienced a major complication. Overall, 7 patients (10.4%) required surgery: in two cases because of local recurrence, in one case for an intraprocedural complication not amenable to endoscopic treatment, in three patients with R1 vertical margins, and in the last patient because of an aggressive pathology (i.e. signet ring cell adenocarcinoma). The mean follow-up of patients with neoplastic lesions was 36.6 ± 13.1 months. ESD for early gastric cancer is a safe and effective technique when performed by experienced Endoscopists also in Western setting. When comparing the outcomes of the ESD in patients with standard and extended indication there is no significant difference in terms of complete resection, complications and local recurrence rates. Larger Western studies are needed to clearly define the role and the outcomes of ESD in regions at low incidence for gastric neoplasia.

Endoscopic Submucosal Tunnel Dissection for Large Gastric Neoplastic Lesions: A Case-Matched Controlled Study.

Aim To evaluate the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) for resection of large superficial gastric lesions (SGLs). Methods The clinicopathological records of patients performed with ESTD or endoscopic submucosal dissection (ESD) for SGLs between January 2012 and January 2014 were retrospectively reviewed. 7 cases undergoing ESTD were enrolled to form the ESTD group. The cases were individually matched at a 1 : 1 ratio to other patients performed with ESD according to lesion location, ulcer or scar findings, resected specimen area, operation time and operators, and the matched cases constituting the ESD group. The treatment outcomes were compared between the two groups. Results The mean specimen size was 46 mm. 10 lesions were located in the cardia and 4 lesions in the lesser curvature of the lower gastric body. En bloc resection was achieved for all lesions. The mean ESTD resection time was 69 minutes as against 87.7 minutes for the ESD (P = 0.01). The mean resection speed was faster for ESTD than for ESD (18.86 mm2/min versus 13.76 mm2/min, P = 0.03). There were no significant differences regarding the safety and curability during the endoscopic follow-up (mean 27 months). Conclusions ESTD is effective and safe for the removal of SGLs and appears to be an optimal option for patients with large SGLs at suitable sites.

Endoscopic submucosal dissection versus endoscopic mucosal resection for type 0-II superficial gastric lesions larger than 20 mm.

Background:Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are increasingly used for the treatment of superficial gastrointestinal neoplasia. However, the limits and the indications for each technique are still debated. Our retrospective study aimed to compare these techniques in patients with gastric flat lesions larger than 20 mm without the non-lifting sign.Methods:Between January 2013 and July 2016, a total of 36 patients with early gastric flat lesions larger than 20 mm and without the non-lifting sign were resected by ESD and were followed up by endoscopy. As a control group, 40 EMR cases from our database were matched. En bloc and curative resection were compared between the two groups according to histological assessment, tumor size, recurrence, complication rate, and procedure time. A Kaplan-Meier comparison was performed for both groups with a log-rank test to compare the survival curves; the chi-square test was employed for other parameters.Results:En bloc resection rate and curative resection rate were significantly higher in the ESD group than in the EMR group. Procedure time was significantly longer in the ESD group. No significant differences were found in the recurrence and complication rates, although the former were higher in the EMR group and the latter in the ESD group. Survival curves were similar for both groups.Conclusions:Our retrospective analysis seems to confirm a clear advantage for ESD over EMR in removing early superficial gastric neoplasm. Although ESD has expanded the endoscopic resectability of endoscopic gastric lesions, EMR may still be considered one of the therapeutic options for flat gastric lesions without the non-lifting sign.

Predicting outcomes of gastric endoscopic submucosal dissection using a Bayesian approach: a step for individualized risk assessment.

Background and study aims Efficacy and adverse events probabilities influence decisions regarding the best options to manage patients with gastric superficial lesions. We aimed at developing a Bayesian model to individualize the prediction of outcomes after gastric endoscopic submucosal dissection (ESD). Patients and methods Data from 245 gastric ESD were collected, including patient and lesion factors. The two endpoints were curative resection and post-procedural bleeding (PPB). Logistic regression and Bayesian networks were built for each outcome; their predictive value was evaluated in-sample and validated through leave-one-out and cross-validation. Clinical decision support was enhanced by the definition of risk matrices, direct use of Bayesian inference software and by a developed online platform. Results ESD was curative in 85.3 % and PPB occurred in 7.7 % of patients. In univariate analysis, male sex, ASA status, carcinoma histology, polypoid or depressed morphology, and lesion size ≥ 20 mm were associated with non-curative resection, while ASA status, antithrombotics and lesion size ≥ 20 mm were associated with PPB. Naïve Bayesian models presented AUROCs of ~80 % in the derivation cohort and ≥ 74 % in cross-validation for both outcomes. Risk matrices were computed, showing that lesions with cancer at biopsies, ≥ 20 mm, proximal or in the middle third, and polypoid are more prone to non-curative resection. PPB risk was < 5 % in lesions < 20 mm in the absence of antithrombotics. Conclusions The derived Bayesian model presented good discriminative power in the prediction of ESD outcomes and can be used to predict individualized probabilities, improving patient information and supporting clinical and management decisions.

P.12.14: Endoscopic Submucosal Dissection for Gastric Superficial Lesions: The Experience of a Single Center in Italy

P.12.14: Endoscopic Submucosal Dissection for Gastric Superficial Lesions: The Experience of a Single Center in Italy

Histomorphologic features of early gastric carcinoma treated by endoscopic submucosal dissection: relation to efficiency of endoscopic resection

Objective: Early gastric cancer (EGC) is defined as cancer invasion confined to the mucosa or submucosa, irrespective of lymph node metastasis. Recently endoscopic submucosal dissection (ESD) has been widely accepted for the treatment for dysplasia and EGC without lymph node metastases. While the method has been advanced in Far East countries, ESD is still being developed in Europe and has not gained enough popularity although it has been recommended as the treatment of choice for superficial gastric neoplastic lesions by European Society of Gastrointestinal Endoscopy (ESGE) in 2015.Methods: The aim of the study was to perform a retrospective analysis of clinical and histomorphologic features of 58 cases of EGCs removed by ESD in a university hospital in Western Pomerania in Poland and to evaluate factors related to the efficiency of ESD resection.Results: With univariate analysis, indications for ESD with the highest R0 rate were found in EGCs limited to mucosa (T1a, small mucosal, M), without muscularis mucosa invasion, localised in the middle/lower part of stomach and intestinal type in histological examination. The R0 complete resection rate was significantly (p < 0.0001) lower for T1b than that for T1a tumours (21.4% vs. 100%). Tumours with submucosal involvement were associated with lower efficiency of ESD procedure.Conclusions: Our data showed that in EGCs with favourable histomorphologic characteristics, ESD seemed to be a totally efficient and safe method of treatment in a European small-volume centre. R0 resection rate reached 81.1% of cases and median time of the ESD procedure was 61.5 min.

How Sensitive Is the Upper Gastrointestinal Tract to 90Y Radioembolization? A Histologic and Dosimetric Analysis in a Porcine Model.

Six female pigs underwent transfemoral angiography and infusion of 90Y-resin microspheres into arteries supplying part of the gastric wall. Esophagogastroduodenoscopy was performed after 4 wk to assess interim gastrointestinal health. Animals were monitored for side effects for 9 wk after 90Y infusion, after which they were euthanized and their upper gastrointestinal tracts were excised for analysis. Histologic sections were used to map microsphere location, and a microdosimetric evaluation was performed to determine the absorbed-dose profile within the gastrointestinal wall. 90Y radioembolization dosages from 46.3 to 105.1 MBq were infused, resulting in average absorbed doses of between 35.5 and 91.9 Gy to the gastric wall. No animal exhibited any signs of pain or gastrointestinal distress through the duration of the study. Excised tissue showed 1-2 small (<3.0 cm2) healed or healing superficial gastric lesions in 5 of 6 animals. Histologic analysis demonstrated that lesion location was superficial to areas of abnormally high microsphere deposition. An analysis of microsphere deposition patterns within the gastrointestinal wall indicated a high preference for submucosal deposition. Dosimetric evaluation at the luminal mucosa performed on the basis of microscopic microsphere distribution confirmed that 90Y dosimetry techniques conventionally used in hepatic dosimetry provide a first-order estimate of absorbed dose. The upper gastrointestinal tract may be less sensitive to 90Y radioembolization than previously thought. Lack of charged-particle equilibrium at the luminal mucosa may contribute to decreased toxicity of 90Y radioembolization compared with external-beam radiation therapy in gastrointestinal tissue. Clinical examples of injury from 90Y nontarget embolization have likely resulted from relatively large 90Y activities being deposited in small tissue volumes, resulting in absorbed doses in excess of 100 Gy.