Conventional versus traction-assisted endoscopic submucosal dissection for gastric neoplasms: a multicenter, randomized controlled trial (with video)

BACKGROUND AND AIMS

The aim of this study was to clarify whether dental floss clip (DFC) traction improves the technical outcomes of endoscopic submucosal dissection (ESD).

METHODS

A superiority, randomized control trial was conducted at 14 institutions across Japan. Patients with single gastric neoplasm meeting the indications of the Japanese guidelines for gastric treatment were enrolled and assigned to receive conventional ESD or DFC traction-assisted ESD (DFC-ESD). Randomization was performed according to a computer-generated random sequence with stratification by institution, tumor location, tumor size, and operator experience. The primary endpoint was ESD procedure time, defined as the time from the start of the submucosal injection to the end of the tumor removal procedure.

RESULTS

Between July 2015 and September 2016, 640 patients underwent randomization. Of these, 316 patients who underwent conventional ESD and 319 patients who underwent DFC-ESD were included in our analysis. The mean ESD procedure time was 60.7 and 58.1 minutes for conventional ESD and DFC-ESD, respectively (P = .45). Perforation was less frequent in the DFC-ESD group (2.2% vs .3%, P = .04). For lesions located in the greater curvature of the upper or middle stomach, the mean procedure time was significantly shorter in the DFC-ESD group (104.1 vs 57.2 minutes, P = .01).

CONCLUSIONS

Our findings suggest that DFC-ESD does not result in shorter procedure time in the overall patient population, but it can reduce the risk of perforation. When selectively applied to lesions located in the greater curvature of the upper or middle stomach, DFC-ESD provides a remarkable reduction in procedure time.

Prediction model of bleeding after endoscopic submucosal dissection for early gastric cancer: BEST-J score

OBJECTIVE

Bleeding after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is a frequent adverse event after ESD. We aimed to develop and externally validate a clinically useful prediction model (BEST-J score: Bleeding after ESD Trend from Japan) for bleeding after ESD for EGC.

DESIGN

This retrospective study enrolled patients who underwent ESD for EGC. Patients in the derivation cohort (n=8291) were recruited from 25 institutions, and patients in the external validation cohort (n=2029) were recruited from eight institutions in other areas. In the derivation cohort, weighted points were assigned to predictors of bleeding determined in the multivariate logistic regression analysis and a prediction model was established. External validation of the model was conducted to analyse discrimination and calibration.

RESULTS

A prediction model comprised 10 variables (warfarin, direct oral anticoagulant, chronic kidney disease with haemodialysis, P2Y12 receptor antagonist, aspirin, cilostazol, tumour size >30 mm, lower-third in tumour location, presence of multiple tumours and interruption of each kind of antithrombotic agents). The rates of bleeding after ESD at low-risk (0 to 1 points), intermediate-risk (2 points), high-risk (3 to 4 points) and very high-risk (≥5 points) were 2.8%, 6.1%, 11.4% and 29.7%, respectively. In the external validation cohort, the model showed moderately good discrimination, with a c-statistic of 0.70 (95% CI, 0.64 to 0.76), and good calibration (calibration-in-the-large, 0.05; calibration slope, 1.01).

CONCLUSIONS

In this nationwide multicentre study, we derived and externally validated a prediction model for bleeding after ESD. This model may be a good clinical decision-making support tool for ESD in patients with EGC.

Risk factors for bleeding after endoscopic submucosal dissection for gastric lesions

AIM

To assess risk factors for bleeding after gastric endoscopic submucosal dissection (ESD) and to develop preventive measures.

METHODS

This retrospective study was performed in a tertiary referral center. A total of 328 patients underwent ESD for 398 gastric neoplasms between July 2007 and June 2009. The main outcome was association between post-ESD bleeding and the following: age; sex; comorbidities; daily use of medicine potentially related to gastric injury/bleeding; location, size, and histological depth of lesions; ulceration; experience of operator coagulating the ulcer floor, and duration of operation. We also determined the relationship between the location of post-ESD bleeding and risk factors for hemorrhage.

RESULTS

Univariate analysis revealed significant risk factors: tumor location [odds ratio (OR), 2.86; 95% CI: 1.21-6.79, P = 0.024], coagulator experience (OR, 4.29; 95% CI: 1.43-12.86, P = 0.009), and medicine potentially related to gastric injury/bleeding (OR, 2.80; 95% CI: 1.14-6.90, P = 0.039). Multivariate logistic regression analysis confirmed significant, independent risk factors: tumor in lower third of stomach (OR, 2.47; 95% CI: 1.02-5.96, P = 0.044), beginner coagulator (OR, 3.93; 95% CI: 1.29-11.9, P = 0.016), and medicine (OR, 2.76; 95% CI: 1.09-6.98, P = 0.032). We classified cases of post-ESD bleeding into two groups (bleeding at the ulcer margin vs bleeding at the center) and found that bleeding at the margin occurred more frequently with beginner coagulators compared with experts (OR, 16.00; 95% CI: 1.22-210.59, P = 0.040).

CONCLUSION

Beginner coagulators, tumor in the antrum, and medicines were significant risk factors for post-ESD bleeding. Bleeding at the ulcer margin frequently occurred with beginner operators.

Management of adverse events related to endoscopic resection of upper gastrointestinal neoplasms: Review of the literature and recommendations from experts

Prevention therapy is recommended for lesions >1/2 of the esophageal circumference. Locoregional steroid injection is recommended for lesions >1/2-3/4 of the esophageal circumference and oral steroids are recommended for lesions >1/2 of the subtotal circumference. For lesions of the entire circumference, oral steroid combined with injection steroid is considered. Endoscopic balloon dilatation (EBD) is the first choice of treatment for stricture after esophageal endoscopic submucosal dissection (ESD). Radical incision and cutting or self-expandable metallic stent can be considered for refractory stricture after EBD. In case of intraoperative perforation during esophageal ESD, endoscopic clip closure should be initially attempted. Surgery is considered for treatment of delayed perforation. Current standard practice for prevention of delayed bleeding after gastric ESD includes prophylactic coagulation of vessels on post-ESD ulcers and giving proton pump inhibitors. Chronic kidney disease stage 4 or 5, multiple antithrombotic drug use, anticoagulant use, and heparin bridging therapy are high-risk factors for delayed bleeding after gastric ESD. Intraoperative perforation during gastric ESD is initially managed by endoscopic clip closure. If endoscopic clip closure is difficult, other methods such as over-the-scope clip (OTSC), polyglycolic acid (PGA) sheet shielding etc. are attempted. Delayed perforation usually requires surgical intervention, but endoscopic closure by OTSC or PGA sheet may be considered. Resection of three-quarters of the circumference is a risk factor for stenosis after gastric ESD. Giving prophylactic local steroid injection and/or oral steroid is reported, but effectiveness has not been fully verified as has been done for esophageal stricture. The main management method for gastric stenosis is EBD but it may cause perforation.

Complications related to gastric endoscopic submucosal dissection and their managements

Endoscopic submucosal dissection (ESD) for early gastric cancer is a well-established procedure with the advantage of resection in an en bloc fashion, regardless of the size, shape, coexisting ulcer, and location of the lesion. However, gastric ESD is a more difficult and meticulous technique, and also requires a longer procedure time, than conventional endoscopic mucosal resection. These factors naturally increase the risk of various complications. The two most common complications accompanying gastric ESD are bleeding and perforation. These complications are known to occur both intraoperatively and postoperatively. However, there are other rare but serious complications related to gastric ESD, including aspiration pneumonia, stenosis, venous thromboembolism, and air embolism. Endoscopists should have sufficient knowledge about such complications and be prepared to deal with them appropriately, as successful management of complications is necessary for the successful completion of the entire ESD procedure.

Polyglycolic acid sheets and fibrin glue decrease the risk of bleeding after endoscopic submucosal dissection of gastric neoplasms (with video)

BACKGROUND

The prevention of bleeding after endoscopic submucosal dissection (ESD) for gastric neoplasms is still an important problem.

OBJECTIVE

To investigate the efficacy and safety of a shielding method that uses polyglycolic acid (PGA) sheets and fibrin glue to prevent post-ESD bleeding in high-risk patients.

DESIGN

A nonrandomized trial with historical control subjects.

SETTING

A single academic hospital in Japan.

PATIENTS

From July 2013 to February 2014, 45 ESD-induced ulcers in 41 patients with a high risk of bleeding were enrolled in a study group. Forty-one consecutive ESD-induced ulcers in 37 control subjects with a high risk of bleeding were treated in 2013 before the first enrollment.

INTERVENTIONS

We placed PGA sheets on the mucosal defect and fixed with fibrin glue in the study group.

MAIN OUTCOME MEASUREMENTS

The post-ESD bleeding rate.

RESULTS

The post-ESD bleeding occurred at a rate of 6.7% in the study group (3/45 lesions) and 22.0% in the historical control group (9/41 lesions). There was a significant difference in the post-ESD bleeding rate between the 2 groups (P = .041).

LIMITATIONS

A nonrandomized trial with historical control subjects; a single-center analysis; small sample size.

CONCLUSIONS

The endoscopic tissue shielding method with PGA sheets and fibrin glue appears to be promising for the prevention of post-ESD bleeding. (

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000011058.).

Trend and risk factors of diverticulosis in Japan: age, gender, and lifestyle/metabolic-related factors may cooperatively affect on the colorectal diverticula formation

BACKGROUND

Despite the marked increase of diverticulosis, its risk factors have not been adequately elucidated. We therefore aim to identify significantly associated factors with diverticulosis. We also aim to investigate the present state of diverticulosis in Japan.

METHODS

We reviewed the medical records from 1990 to 2010 that included the data of consecutive 62,503 asymptomatic colonoscopy examinees from the general population in Japan. Most recent 3,327 examinees were analyzed with 16 background factors.

RESULTS

Among the 62,503 subjects (47,325 men and 15,178 women; 52.1 ± 9.2 years old), diverticulosis was detected in 11,771 subjects (18.8%; 10,023 men and 1,748 women). The incidences of diverticulosis in 1990-2000 and 2001-2010 were respectively 13.0% (3,771 of 29,071) and 23.9% (8,000 of 33,432): the latter was much higher than the former in all age groups and for both genders. Considering the anatomical locations of colorectal diverticula, left-sided ones have markedly increased with age but not significantly changed with times. Univariate analyses of the 3,327 subjects showed significant association of diverticulosis with four basic factors (age, sex, body mass index, blood pressure), three life style-related factor (smoking, drinking, severe weight increase in adulthood), and two blood test values (triglyceride, HbA1c). The multiple logistic analysis calculating standardized coefficients (β) and odds ratio (OR) demonstrated that age (β = 0.217-0.674, OR = 1.24-1.96), male gender (β = 0.185, OR = 1.20), smoking (β = 0.142-0.200, OR = 1.15-1.22), severe weight increase in adulthood (β = 0.153, OR = 1.17), HbA1c (β = 0.136, OR = 1.15), drinking (β = 0.109, OR = 1.11), and serum triglyceride (β = 0.098, OR = 1.10) showed significantly positive association with diverticulosis whereas body mass index and blood pressure did not.

CONCLUSIONS

The large-scale data of asymptomatic colonoscopy examinees from the general population from 1990 to 2010 indicated that the prevalence of diverticulosis is still increasing in Japan. Age, male gender, smoking, severe weight increase in adulthood, serum HbA1c, drinking, and serum triglyceride showed significant positive association with diverticulosis.

A multicenter survey of the management after gastric endoscopic submucosal dissection related to postoperative bleeding

BACKGROUND AND AIMS

Bleeding is a major complication after gastric endoscopic submucosal dissection (ESD). An evidence-based strategy for postoperative care related to delayed bleeding is required. We conducted a multicenter survey to assess the current status of management after gastric ESD.

METHODS

A total of 1,814 gastric epithelial neoplasms in 2009 at ten tertiary referral centers were enrolled. The current status of the management after gastric ESD (use of an antisecretory drug, food intake, and second-look endoscopy) at participating hospitals was assessed. Furthermore, the rate of post-ESD bleeding and the differences in each parameter were retrospectively analyzed.

RESULTS

Postoperative bleeding occurred in 100 cases (5.5%), which included 62 cases of bleeding within 24 h after ESD. In all of the hospitals, proton pump inhibitors (PPIs) were used. The median administration period was 56 days (range 14-60 days). Food intake was resumed from postoperative day (POD) 1 in 4 hospitals and from POD 2 in 6 hospitals. Second-look endoscopy was performed for almost all cases, fewer cases, and rarely or none in 6, 2, and 2 hospitals, respectively. The day of second-look endoscopy varied among hospitals. There was no statistical relationship between the postoperative bleeding rate and the differences in these three parameters.

CONCLUSIONS

Post-ESD management (duration of PPI use, resumption of food intake, and performance of second-look endoscopy) varied among the medical centers; thus, randomized controlled trials are required for an optimal strategy after gastric ESD.

Highly accurate artificial intelligence systems to predict the invasion depth of gastric cancer: efficacy of conventional white-light imaging, nonmagnifying narrow-band imaging, and indigo-carmine dye contrast imaging

BACKGROUND AND AIMS

Diagnosing the invasion depth of gastric cancer (GC) is necessary to determine the optimal method of treatment. Although the efficacy of evaluating macroscopic features and EUS has been reported, there is a need for more accurate and objective methods. The primary aim of this study was to test the efficacy of novel artificial intelligence (AI) systems in predicting the invasion depth of GC.

METHODS

A total of 16,557 images from 1084 cases of GC for which endoscopic resection or surgery was performed between January 2013 and June 2019 were extracted. Cases were randomly assigned to training and test datasets at a ratio of 4:1. Through transfer learning leveraging a convolutional neural network architecture, ResNet50, 3 independent AI systems were developed. Each system was trained to predict the invasion depth of GC using conventional white-light imaging (WLI), nonmagnifying narrow-band imaging (NBI), and indigo-carmine dye contrast imaging (Indigo).

RESULTS

The area under the curve of the WLI AI system was .9590. The lesion-based sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the WLI AI system were 84.4%, 99.4%, 94.5%, 98.5%, and 92.9%, respectively. The lesion-based accuracies of the WLI, NBI, and Indigo AI systems were 94.5%, 94.3%, and 95.5%, respectively, with no significant difference.

CONCLUSIONS

These new AI systems trained with multiple images from different angles and distances could predict the invasion depth of GC with high accuracy. The lesion-based accuracy of the WLI, NBI, and Indigo AI systems was not significantly different.

Bleeding after endoscopic submucosal dissection: Risk factors and preventive methods

Endoscopic submucosal dissection (ESD) has become widely accepted as a standard method of treatment for superficial gastrointestinal neoplasms because it enables en block resection even for large lesions or fibrotic lesions with minimal invasiveness, and decreases the local recurrence rate. Moreover, specimens resected in an en block fashion enable accurate histological assessment. Taking these factors into consideration, ESD seems to be more advantageous than conventional endoscopic mucosal resection (EMR), but the associated risks of perioperative adverse events are higher than in EMR. Bleeding after ESD is the most frequent among these adverse events. Although post-ESD bleeding can be controlled by endoscopic hemostasis in most cases, it may lead to serious conditions including hemorrhagic shock. Even with preventive methods including administration of acid secretion inhibitors and preventive hemostasis, post-ESD bleeding cannot be completely prevented. In addition high-risk cases for post-ESD bleeding, which include cases with the use of antithrombotic agents or which require large resection, are increasing. Although there have been many reports about associated risk factors and methods of preventing post-ESD bleeding, many issues remain unsolved. Therefore, in this review, we have overviewed risk factors and methods of preventing post-ESD bleeding from previous studies. Endoscopists should have sufficient knowledge of these risk factors and preventive methods when performing ESD.

Background factors of reflux esophagitis and non-erosive reflux disease: a cross-sectional study of 10,837 subjects in Japan

BACKGROUND

Despite the high prevalence of gastroesophageal reflux disease (GERD), its risk factors are still a subject of controversy. This is probably due to inadequate distinction between reflux esophagitis (RE) and non-erosive reflux disease (NERD), and is also due to inadequate evaluation of adjacent stomach. Our aim is therefore to define background factors of RE and NERD independently, based on the evaluation of Helicobacter pylori infection and gastric atrophy.

METHODS

We analyzed 10,837 healthy Japanese subjects (6,332 men and 4,505 women, aged 20-87 years) who underwent upper gastrointestinal endoscopy. RE was diagnosed as the presence of mucosal break, and NERD was diagnosed as the presence of heartburn and/or acid regurgitation in RE-free subjects. Using GERD-free subjects as control, background factors for RE and NERD were separately analyzed using logistic regression to evaluate standardized coefficients (SC), odds ratio (OR), and p-value.

RESULTS

Of the 10,837 study subjects, we diagnosed 733 (6.8%) as RE and 1,722 (15.9%) as NERD. For RE, male gender (SC = 0.557, OR = 1.75), HP non-infection (SC = 0.552, OR = 1.74), higher pepsinogen I/II ratio (SC = 0.496, OR = 1.64), higher BMI (SC = 0.464, OR = 1.60), alcohol drinking (SC = 0.161, OR = 1.17), older age (SC = 0.148, OR = 1.16), and smoking (SC = 0.129, OR = 1.14) are positively correlated factors. For NERD, HP infection (SC = 0.106, OR = 1.11), female gender (SC = 0.099, OR = 1.10), younger age (SC = 0.099, OR = 1.10), higher pepsinogen I/II ratio (SC = 0.099, OR = 1.10), smoking (SC = 0.080, OR = 1.08), higher BMI (SC = 0.078, OR = 1.08), and alcohol drinking (SC = 0.076, OR = 1.08) are positively correlated factors. Prevalence of RE in subjects with chronic HP infection and successful HP eradication denotes significant difference (2.3% and 8.8%; p<0.0001), whereas that of NERD shows no difference (18.2% and 20.8%; p = 0.064).

CONCLUSIONS

Significantly associated factors of NERD are considerably different from those of RE, indicating that these two disorders are pathophysiologically distinct. Eradication of Helicobacter pylori may have disadvantageous effects on RE but not on NERD.

Rapid and sensitive detection of early esophageal squamous cell carcinoma with fluorescence probe targeting dipeptidylpeptidase IV

Early detection of esophageal squamous cell carcinoma (ESCC) is an important prognosticator, but is difficult to achieve by conventional endoscopy. Conventional lugol chromoendoscopy and equipment-based image-enhanced endoscopy, such as narrow-band imaging (NBI), have various practical limitations. Since fluorescence-based visualization is considered a promising approach, we aimed to develop an activatable fluorescence probe to visualize ESCCs. First, based on the fact that various aminopeptidase activities are elevated in cancer, we screened freshly resected specimens from patients with a series of aminopeptidase-activatable fluorescence probes. The results indicated that dipeptidylpeptidase IV (DPP-IV) is specifically activated in ESCCs, and would be a suitable molecular target for detection of esophageal cancer. Therefore, we designed, synthesized and characterized a series of DPP-IV-activatable fluorescence probes. When the selected probe was topically sprayed onto endoscopic submucosal dissection (ESD) or surgical specimens, tumors were visualized within 5 min, and when the probe was sprayed on biopsy samples, the sensitivity, specificity and accuracy reached 96.9%, 85.7% and 90.5%. We believe that DPP-IV-targeted activatable fluorescence probes are practically translatable as convenient tools for clinical application to enable rapid and accurate diagnosis of early esophageal cancer during endoscopic or surgical procedures.

Endoscopic tissue shielding method with polyglycolic acid sheets and fibrin glue to cover wounds after colorectal endoscopic submucosal dissection (with video)

BACKGROUND

Colorectal endoscopic submucosal dissection (ESD) has made it possible to resect large specimens in an en bloc fashion. However, this can lead to postoperative adverse events, such as perforation and bleeding. Prevention of adverse events after colorectal ESD is therefore an important goal.

OBJECTIVE

To evaluate the utility of a shielding method using polyglycolic acid (PGA) sheets and fibrin glue to manage ulcers after colorectal ESD.

DESIGN

Prospective, single-arm, pilot study.

SETTING

Single tertiary care center for colorectal ESD in Japan.

PATIENTS

Ten patients with 10 colorectal tumors scheduled for ESD were enrolled between September and November 2012.

INTERVENTIONS

Just after ESD, we placed PGA sheets on the mucosal defect with biopsy forceps. After the whole defect was covered, we sprayed fibrin glue through a special double-lumen spraying tube. We sprayed fibrinogen through 1 lumen and then thrombin through the other lumen.

MAIN OUTCOME MEASUREMENTS

Success rate, mean procedure time, and adverse events associated with the covering technique and the persistence of PGA sheets at follow-up colonoscopy.

RESULTS

All 10 tumors were successfully resected. Mean tumor size was 39.7 ± 15.2 mm. All mucosal defects were successfully covered with PGA sheets. Mean procedure time was 18.7 ± 15.9 minutes. No procedure-related adverse events occurred. Upon colonoscopy 9 to 12 days after ESD, the PGA sheets were still fixed on the whole defect in 8 patients.

LIMITATIONS

Small sample size.

CONCLUSIONS

Our technique, which uses PGA sheets and fibrin glue, appears to shield mucosal defects, and it may be effective in reducing postoperative adverse events.

Risk of metastasis in adenocarcinoma of the esophagus: a multicenter retrospective study in a Japanese population

BACKGROUND

Little is known about the specific risks of metastasis in esophageal adenocarcinoma in relation to invasion depth or other pathologic factors.

METHODS

We conducted a multicenter retrospective study in 13 high-volume centers in Japan from January 2000 to October 2014 to elucidate the risk of metastasis of esophageal adenocarcinoma. A total of 458 patients (217 surgically resected and 241 endoscopically resected) with esophageal adenocarcinoma or esophagogastric adenocarcinoma involving the esophagus were included. Metastasis was considered positive if there was histologically confirmed metastasis in the surgical specimen or clinically confirmed metastasis during follow-up. Metastasis was considered negative if no metastasis was identified in resected specimens and during follow-up in patients treated surgically or no metastasis during follow-up for >5 years in patients treated by endoscopic resection.

RESULTS

Metastasis was identified in 72 patients. Multivariate analysis confirmed lymphovascular involvement [odds ratio (OR) 6.20; 95 % confidence interval (CI) 3.12-12.32; p < 0.001], a poorly differentiated component (OR 3.69; 95 % CI 1.92-7.10; p < 0.001), and lesion size >30 mm (OR 3.12; 95 % CI 1.63-5.97; p = 0.001) as independent risk factors for metastasis. No metastasis was detected in patients with mucosal cancer without lymphovascular involvement and a poorly differentiated component (0/186 lesions) or in patients with cancer invading the submucosa (1-500 µm) without lymphovascular involvement, a poorly differentiated component, and ≤30 mm (0/32 lesions).

CONCLUSIONS

Mucosal and submucosal cancers (1-500 µm invasion) without risk factors have a low incidence of metastasis and may thus be good candidates for endoscopic resection.

An effective training system for endoscopic submucosal dissection of gastric neoplasm

BACKGROUND AND STUDY AIMS

A standard training system for endoscopic submucosal dissection (ESD) remains to be established. In this study, we evaluated the validity of our training program for gastric ESD.

PATIENTS AND METHODS

Four trainees performed gastric ESD for a total of 117 lesions in 107 patients (27 to 30 consecutive lesions per trainee) at a tertiary referral center during 2 years in the training program. Trainees, who already had the fundamental skills and knowledge needed for ESD, each assisted at 40 gastric ESD procedures, then in 20 cases applied post-ESD coagulation (PEC) to gastric mucosal defects; they then began to perform ESD, starting with gastric antral lesions. Treatment outcomes, including mean procedure time, and rates of en bloc resection, en bloc plus R0 resections, complications, and self-completion, were evaluated, for the initial 15 and subsequent 12 to 15 cases.

RESULTS

Overall rates of en bloc resection and en bloc plus R0 resection were as high as 100 % and 96.6 %, respectively. Regarding complications, seven cases of delayed hemorrhage (6.0 %) and three cases of perforation (2.6 %) occurred; all complications were solved endoscopically. The most frequent reason for operator change was lack of submucosal dissection skill. The self-completion rate was more than 80 % even in the early period, and did not increase for later cases.

CONCLUSIONS

Our training system enabled novice operators to perform gastric ESD without a decline in clinical outcomes. Key features of this training are prior intensive learning and actual ESD during the learning period under expert supervision.

Effective training system in colorectal endoscopic submucosal dissection

Although colorectal endoscopic submucosal dissection (ESD) is superior to endoscopic mucosal resection (EMR) in en bloc resection rate, it is technically quite difficult because of the anatomical and histological characteristics of the colorectal wall. This difficulty prevents wide spread of the technique. Establishment of the training system for colorectal ESD is necessary to standardize training and to achieve wider acceptance of this technique. Herein, we describe our training system for colorectal ESD, and assess the validity of the training system for colorectal ESD, based on the clinical outcomes and learning curve of trainees. Our training system for colorectal ESD would help the spread of this procedure.

Long-term outcomes of endoscopic resection and metachronous cancer after endoscopic resection for adenocarcinoma of the esophagogastric junction in Japan

BACKGROUND AND AIMS

Endoscopic resection (ER) of superficial adenocarcinoma of the esophagogastric junction (AEGJ) has been shown to be safe and effective. However, long-term data in patients undergoing ER for superficial AEGJ in Japan are still limited. The aim of this study was to determine the effect of ER on survival and occurrence of metachronous cancer of patients with superficial AEGJ.

METHODS

A retrospective analysis of patients who underwent or endoscopic submucosal dissection (ESD) for superficial AEJG in 13 centers in Japan was performed. The patients were classified as either low risk or high risk for lymph node metastasis based on histologic features. The incidence of metachronous AEGJ as well as overall survival and disease-specific survival rates were calculated.

RESULTS

A total of 372 patients who underwent ER were included, in which 277 patients were low risk and 95 high risk for lymph node metastasis. Five-year cumulative incidences of local recurrence were 13% and .5% in the EMR and ESD groups, respectively (P < .01). Six AEGJ deaths were observed in the high-risk group and none in the low-risk group. The 5-year overall survival rates in the low-risk group without additional treatment, the high-risk group with additional treatment, and the high-risk group without additional treatment were 93.9%, 77.7%, and 81.6%, respectively. The 5-year disease-specific survival rates in the 3 groups were 100%, 94.4%, and 92.8%, respectively. The 5-year cumulative incidence of metachronous AEGJ in 316 patients without additional treatment was 1.1%.

CONCLUSIONS

Favorable long-term outcomes with ER were observed in patients with AEGJ who met the low-risk criteria for lymph node metastasis. ESD was a reasonable and effective treatment in Japanese patients.

Polyglycolic acid sheets with fibrin glue can prevent esophageal stricture after endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

Suitable techniques for the prevention of stricture formation after esophageal endoscopic submucosal dissection (ESD) are still lacking. We investigated the efficacy of polyglycolic acid (PGA) sheets with fibrin glue to prevent post-ESD stricture.

PATIENTS AND METHODS

We conducted a pilot study on a total of eight consecutive patients who underwent esophageal ESD that left a mucosal defect of more than three-quarters of the esophageal circumference. PGA sheets were attached to the defect with fibrin glue immediately after the completion of ESD. The primary endpoint was the incidence of post-ESD stricture. The secondary endpoints were the number of sessions of endoscopic balloon dilation (EBD) required to resolve any stricture and the rate of complications.

RESULTS

There were no adverse events related to the use of PGA sheets and fibrin glue. Post-ESD stricture occurred in 37.5 % of the subjects and 0.8 ± 1.2 sessions of EBD were required.

CONCLUSION

The use of PGA sheets and fibrin glue after esophageal ESD is a novel method that radically decreases the incidence of esophageal stricture and the number of EBD sessions subsequently required. University Hospital Medical Network Clinical Trial Registry (UMIN000011058).

Oxyntic gland neoplasm of the stomach: expanding the spectrum and proposal of terminology

Gastric neoplasms exhibiting oxyntic gland differentiation typically are composed of cells with mild cytonuclear atypia differentiating to chief cells and to a lesser extent, parietal cells. Such tumors with atypical features have been reported also and terminology for this entity remains a matter of considerable debate. We analyzed and classified 26 tumors as oxyntic gland neoplasms within mucosa (group A, eight tumors) and with submucosal invasion. The latter was divided further into those with typical histologic features (group B, 14 tumors) and atypical features, including high-grade nuclear or architectural abnormality and presence of atypical cellular differentiation (group C, four tumors). Groups A and B tumors shared similar histologic features displaying either a chief cell predominant pattern characterized by monotonous chief cell proliferation, or a well-differentiated mixed cell pattern showing admixture of chief and parietal cells resembling fundic gland. In addition, group C tumors displayed atypical cellular differentiation, including mucous neck cell and foveolar epithelium. Moderate or even marked cytological atypia was noted in group C, whereas it was usually mild in the other groups except for three group B tumors with focal moderate atypia. More than 1000 μm submucosal invasion and lymphovascular invasions were recognized only in group C. Mutation analyses identified KRAS mutation in one group C tumor as well as GNAS mutation in in one group A and group B tumors. Intramucosal tumors appear to behave biologically benign and should be classified as "oxyntic gland adenoma". Those with submucosal invasion also have low malignant potential; however, a subset will have atypical features associated with aggressive histologic features and should be designated as "adenocarcinoma of fundic gland type". Especially, we suggest "adenocarcinoma of fundic gland mucosa type" for tumors with submucosal invasion exhibiting atypical cellular differentiation, because the feature is likely to be a sign of aggressive phenotype.

Endoscopic tissue shielding to prevent bleeding after endoscopic submucosal dissection: a prospective multicenter randomized controlled trial

BACKGROUND

Bleeding after endoscopic submucosal dissection (ESD) is a severe adverse event. Recent reports have described the efficacy of the endoscopic shielding method with polyglycolic acid (PGA) sheets and fibrin glue for the prevention of adverse events after ESD. The aim of the present study was to investigate whether the PGA shielding method provides additional benefit in preventing post-ESD bleeding compared with standard care.

METHODS

This was a prospective, multicenter, randomized controlled trial. Patients at high risk of post-ESD bleeding were enrolled in the study. Before ESD, patients were randomized to either the PGA group or the control group. After completing ESD in the PGA group, PGA sheets were placed onto the ulcer floor and adhered with fibrin glue. The primary end point was the post-ESD bleeding rate.

RESULTS

140 eligible patients were enrolled from September 2014 to September 2016, and 137 were included in the intention-to-treat analysis (67 in the PGA group and 70 in the control group). Post-ESD bleeding occurred in three patients (4.5 %) in the PGA group and in four patients (5.7 %) in the control group; there was no significant difference between the two groups (P > 0.99). Post-ESD bleeding tended to occur later in the control group than in the PGA group (median 12.5 days [range 8 - 14] vs. 2 days [range 0 - 7], respectively).

CONCLUSION

The PGA shielding method did not demonstrate a significant effect on the prevention of post-ESD bleeding.

Evaluation of safety of endoscopic biopsy without cessation of antithrombotic agents in Japan

BACKGROUND

Although guidelines in Japan recommend the cessation of antithrombotic agents before endoscopic biopsy, the safety of biopsy without the cessation of these agents has not been evaluated to date in this country. Therefore, we aimed to assess the feasibility of biopsy without cessation of antithrombotic agents in Japan.

METHODS

This was a prospective single-arm study from a single institution. From May 2010 to November 2011, 112 outpatients who were receiving antithrombotic agents because of their high-risk status for a thromboembolic event (after implantation of coronary stent, after valve replacement, or a previous history of thromboembolic event or heart failure due to atrial fibrillation) were enrolled. We evaluated the rate of severe bleeding complications within 2 weeks after endoscopy and the endoscopic bleeding time (EBT) after biopsy in patients who underwent biopsy for endoscopic findings requiring pathology assessment.

RESULTS

Among the 112 participants, 101 biopsies were performed for 48 and 12 outpatients who had had esophagogastroduodenoscopy and colonoscopy, respectively. All the biopsies provided enough specimens to evaluate pathologically. Hemostasis after biopsy was confirmed for all biopsies during endoscopic observation. No patients complained of any bleeding symptoms in the 2-week observation period after biopsy (0/101; 95% confidence interval [CI] 0-3.6%). Concerning the EBT (median 2.2 ± 1.8 min, range 0.5-9 min), there were no significant differences between patients receiving single antithrombotic agents and those receiving multiple agents (2.4 ± 1.4 vs. 2.1 ± 2.1 min), nor were there any significant differences between patients not receiving and receiving warfarin (2.3 ± 1.8 vs. 2.2 ± 1.8 min).

CONCLUSION

Biopsy without cessation of antithrombotic agents, as recommended in Western guidelines, can also be acceptable for Japanese people if performed carefully.

Balloon overtube-guided colorectal endoscopic submucosal dissection

AIM

To evaluate the usefulness of a balloon overtube to assist colorectal endoscopic submucosal dissection (ESD) using a gastroscope.

METHODS

The results of 45 consecutive patients who underwent colorectal ESD were analyzed in a single tertiary endoscopy center. In preoperative evaluation of access to the lesion, difficulties were experienced in the positioning and stabilization of a gastroscope in 15 patients who were thus assigned to the balloon-guided ESD group. A balloon overtube was placed with a gastroscope to provide an endoscopic channel to the lesion in cases with preoperatively identified difficulties related to accessibility. Colorectal ESD was performed following standard procedures. A submucosal fluid bleb was created with hyaluronic acid solution. A circumferential mucosal incision was made to marginate the lesion. The isolated lesion was finally excised from the deeper layers with repetitive electrosurgical dissections with needle knives. The success of colorectal ESD, procedural feasibility, and procedure-related complications were the main outcomes and measurements.

RESULTS

The overall en bloc excision rate of colorectal ESD during this study at our institution was 95.6%. En bloc excision of the lesion was successfully achieved in 13 of the 15 patients (86.7%) in the balloon overtube-guided colorectal ESD group, which was comparable to the results of the standard ESD group with better accessibility to the lesion (30/30, 100%, not statistically significant).

CONCLUSION

Use of a balloon overtube can improve access to the lesion and facilitate scope manipulation for colorectal ESD.

Magnifying endoscopy with narrow-band imaging helps determine the management of gastric adenomas

BACKGROUND

There are no clear clinical criteria for the management of gastric lesions diagnosed as adenomas (Vienna classification category 3) by pre-treatment biopsy. In the present study, we examined the feasibility of magnifying endoscopy with narrow-band imaging (ME-NBI) in discriminating early gastric cancers (Vienna classification category 4 or 5) from adenomas in lesions diagnosed as adenomas by pre-treatment biopsy.

METHODS

This was a single-center cross-sectional retrospective study at a tertiary referral center. One hundred thirty-seven consecutive cases of gastric lesions diagnosed as adenomas in pre-treatment forceps biopsy were examined with conventional non-magnifying endoscopy under white light, non-magnifying chromoendoscopy, and ME-NBI. We investigated the association between the final pathological diagnoses (carcinoma or adenoma) and the following factors: lesion size (mm), color (red or white), macroscopic type (depressed or others), presence of ulceration, and positive ME-NBI finding. The presence of an irregular microvascular pattern or an irregular microsurface pattern with a demarcation line between the lesion and the surrounding area was regarded as a positive ME-NBI finding.

RESULTS

Lesion size was significantly larger in carcinomas than adenomas (P = 0.005). Depressed lesion (P = 0.011), red color (P < 0.001), and positive ME-NBI finding (P < 0.001) were significant predictive factors for carcinoma. Multivariate logistic regression confirmed that red color (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.26-7.34, P = 0.14) and a positive ME-NBI finding (OR 13.68, 95% CI 5.69-32.88, P < 0.001) were independent predictive factors for carcinomas. A positive ME-NBI finding was the strongest predictive factor.

CONCLUSIONS

ME-NBI is useful in planning the management of lesions diagnosed as adenomas by pre-treatment forceps biopsy.

Machine learning-based personalized prediction of gastric cancer incidence using the endoscopic and histologic findings at the initial endoscopy

BACKGROUND AND AIMS

Accurate risk stratification for gastric cancer is required for optimal endoscopic surveillance in patients with chronic gastritis. We aimed to develop a machine learning (ML) model that incorporates endoscopic and histologic findings for an individualized prediction of gastric cancer incidence.

METHODS

We retrospectively evaluated 1099 patients with chronic gastritis who underwent EGD and biopsy sampling of the gastric mucosa. Patients were randomly divided into training and test sets (4:1). We constructed a conventional Cox proportional hazard model and 3 ML models. Baseline characteristics, endoscopic atrophy, and Operative Link on Gastritis-Intestinal Metaplasia Assessment (OLGIM)/Operative Link on Gastritis Assessment (OLGA) stage at initial EGD were comprehensively assessed. Model performance was evaluated using Harrel's c-index.

RESULTS

During a mean follow-up of 5.63 years, 94 patients (8.55%) developed gastric cancer. The gradient-boosting decision tree (GBDT) model achieved the best performance (c-index from the test set, .84) and showed high discriminative ability in stratifying the test set into 3 risk categories (P < .001). Age, OLGIM/OLGA stage, endoscopic atrophy, and history of malignant tumors other than gastric cancer were important predictors of gastric cancer incidence in the GBDT model. Furthermore, the proposed GBDT model enabled the generation of a personalized cumulative incidence prediction curve for each patient.

CONCLUSIONS

We developed a novel ML model that incorporates endoscopic and histologic findings at initial EGD for personalized risk prediction of gastric cancer. This model may lead to the development of effective and personalized follow-up strategies after initial EGD.