A novel artificial intelligence-based endoscopic ultrasonography diagnostic system for diagnosing the invasion depth of early gastric cancer

BACKGROUND

We developed an artificial intelligence (AI)-based endoscopic ultrasonography (EUS) system for diagnosing the invasion depth of early gastric cancer (EGC), and we evaluated the performance of this system.

METHODS

A total of 8280 EUS images from 559 EGC cases were collected from 11 institutions. Within this dataset, 3451 images (285 cases) from one institution were used as a development dataset. The AI model consisted of segmentation and classification steps, followed by the CycleGAN method to bridge differences in EUS images captured by different equipment. AI model performance was evaluated using an internal validation dataset collected from the same institution as the development dataset (1726 images, 135 cases). External validation was conducted using images collected from the other 10 institutions (3103 images, 139 cases).

RESULTS

The area under the curve (AUC) of the AI model in the internal validation dataset was 0.870 (95% CI: 0.796-0.944). Regarding diagnostic performance, the accuracy/sensitivity/specificity values of the AI model, experts (n = 6), and nonexperts (n = 8) were 82.2/63.4/90.4%, 81.9/66.3/88.7%, and 68.3/60.9/71.5%, respectively. The AUC of the AI model in the external validation dataset was 0.815 (95% CI: 0.743-0.886). The accuracy/sensitivity/specificity values of the AI model (74.1/73.1/75.0%) and the real-time diagnoses of experts (75.5/79.1/72.2%) in the external validation dataset were comparable.

CONCLUSIONS

Our AI model demonstrated a diagnostic performance equivalent to that of experts.

Efficacy of prophylactic clip closure in reducing the risk of delayed bleeding after colorectal endoscopic submucosal dissection in patients on anticoagulant therapy: Multicenter prospective study

OBJECTIVES

The high rate of delayed bleeding after colorectal endoscopic submucosal dissection (ESD) in patients undergoing anticoagulant therapy remains a problem. Whether prophylactic clip closure reduces the rate of delayed bleeding in these patients is unclear. This study aimed to evaluate the efficacy of prophylactic clip closure in patients receiving anticoagulants.

METHODS

This multicenter prospective interventional trial was conducted at nine referral centers in Japan. Patients regularly taking anticoagulants, including warfarin potassium or direct oral anticoagulants, and undergoing ESD for colorectal neoplasms were enrolled. The discontinuation of anticoagulants was minimized according to recent guidelines. After the ESD, post-ESD ulcers were prophylactically closed using endoclips. The primary end-point was the incidence of delayed bleeding. The sample size was 45 lesions, and prophylactic clip closure was considered effective when the upper limit of the 90% confidence interval (CI) for delayed bleeding did not exceed 20%.

RESULTS

Forty-five lesions were used, and three were excluded. Complete closure was achieved in 41/42 lesions (97.6%). The overall delayed bleeding rate was low, at 4.9% (2/41; 90% [CI] 0.8-14.5), which was significantly lower than that at the prespecified threshold of 20% (P = 0.007). The median closure procedure time was 17 min, and the median number of clips was nine. No massive delayed bleeding requiring transfusion, interventional radiology, or surgery was observed, and no thromboembolic events were observed.

CONCLUSION

Prophylactic clip closure may reduce the risk of delayed bleeding following colorectal ESD in patients receiving anticoagulants.

TRIAL REGISTRATION

UMIN Clinical Trial Registry (UMIN000036734).

Non-Pure Intestinal Phenotype as an Indicator of Progression in Sporadic Nonampullary Duodenal Adenomas: A Multicenter Retrospective Cohort Study

INTRODUCTION

We aimed to evaluate the natural course of sporadic nonampullary duodenal adenomas (SNDAs) and determine the risk factors of progression.

METHODS

We retrospectively analyzed the follow-up outcomes of patients with biopsy-diagnosed SNDA between April 2010 and March 2016 at 13 institutions. All initial biopsy specimens were centrally evaluated. Only those diagnosed with adenomas were included. Mucinous phenotypes were classified into pure intestinal and non-pure intestinal phenotypes. Cumulative incidence rates of carcinoma and tumor enlargement were evaluated. Tumor enlargement was defined as a ≥25% or 5-mm increase in tumor size.

RESULTS

Overall, 121 lesions were analyzed. Within a median observation period of 32.7 months, 5 lesions were diagnosed as carcinomas; the cumulative 5-year incidence of carcinoma was 9.5%. Male sex ( P = 0.046), initial lesion size ≥10 mm ( P = 0.044), and non-pure intestinal phenotype ( P = 0.019) were significantly associated with progression to carcinoma. Tumor enlargement was observed in 22 lesions, with a cumulative 5-year incidence of 33.9%. Initial lesion size ≥10 mm ( P < 0.001), erythematous lesion ( P = 0.002), high-grade adenoma ( P = 0.002), Ki67 negative ( P = 0.007), and non-pure intestinal phenotype ( P = 0.001) were risk factors of tumor enlargement. In a multivariate analysis, an initial lesion size ≥10 mm ( P = 0.010) and non-pure intestinal phenotype ( P = 0.046) were independent and significant risk factors of tumor enlargement.

DISCUSSION

Lesion size ≥10 mm and non-pure intestinal phenotype on initial biopsy are risk factors of cancer progression and tumor enlargement in cases with SNDA. Thus, management effectiveness may be improved by focusing on lesion size and the mucinous phenotype.

Endoscopic features and clinical course of colorectal carcinoma resected by cold snare polypectomy

BACKGROUND AND AIM

Cold snare polypectomy is commonly performed to remove small colorectal polyps. Accidental resection of carcinomas during this procedure has been reported. Herein, we aimed to clarify the clinicopathological features and clinical course of colorectal carcinomas resected by cold snare polypectomy.

METHODS

This multicenter retrospective cohort study was conducted at 10 Japanese healthcare centers. Of the colorectal lesions resected by cold snare polypectomy between April 2016 and March 2020, lesions pathologically diagnosed as carcinoma were reviewed. Centralized histology (based on the Vienna classification) and endoscopic reviews were performed. The study endpoints were endoscopic features and clinical outcomes of cold snare polypectomy-resected colorectal carcinomas (Vienna category ≥4.2).

RESULTS

We reviewed 74 of the 70 693 lesions resected by cold snare polypectomy. After a central pathological review, 68 lesions were diagnosed as carcinomas. The Japan Narrow-band imaging Expert Team (JNET) classification type 2B, lesion size ≥6 mm, and multinodular morphology were the significant endoscopic predictors of carcinoma resected by cold snare polypectomy. No adverse events related to the procedure occurred. Sixty-three lesions were diagnosed as carcinomas within the mucosal layer, and 34 were curative resections. Of the five carcinoma lesions with submucosal invasion, additional surgery revealed remnant cancer tissues in one lesion. No local or metastatic recurrence was observed during follow-up.

CONCLUSIONS

Although most of the carcinomas resected by cold snare polypectomy were within the mucosal layer, few lesions invading the submucosa were identified. Careful pre-procedural endoscopic evaluation, especially focusing on the JNET classification and multinodular morphology, is recommended.

Plasmablastic lymphoma occurring in ulcerative colitis during treatment with immunosuppressive therapy

A 53-year-old man who had a history of ulcerative colitis (UC) for 2 years underwent colonoscopy as regular follow-up. The results showed an elevated lesion in the descending colon, which was diagnosed as plasmablastic lymphoma (PBL) based on pathological findings. In situ hybridization for the Epstein-Barr virus-encoded RNA probe was positive. Fluorescence in situ hybridization revealed rearrangement of the MYC gene. He had been taking prednisolone, 5-aminosalicylic acid, azathiopurine, and ustekinumab at the diagnosis of PBL and had multiple prior therapies for UC including infliximab, tacrolimus, and tofacitinib due to steroid dependence. PBL is a rare aggressive B cell lymphoma initially described in the oral cavity of human immunodeficiency virus positive patients and it is suspected to have an association with immunocompromised status of patients. The number of cases of PBL in inflammatory bowel disease (IBD) patients is extremely rare. All these patients were administered immunosuppressive therapy including thiopurines or biologics. IBD patients with immunosuppressive therapy have a higher potential for developing lymphoproliferative disorders. Clinicians should be aware of the risk of lymphoma, including PBL.

Diagnostic value of endoscopic ultrasonography for the depth of gastric cancer suspected of submucosal invasion: a multicenter prospective study

BACKGROUND

Although the combination of conventional endoscopy (CE) and endoscopic ultrasonography (EUS) is useful for predicting the depth of early gastric cancer (EGC), the diagnostic value of EUS for submucosal (SM) invasive cancer has not been fully investigated.

METHODS

We conducted a multicenter prospective study from May 2017 to January 2021 to evaluate the validity of a diagnostic strategy combining CE and EUS and to clarify the additional value of EUS for EGC suspected of SM invasion. In each case, the diagnosis was first made using CE, followed by EUS, and finally confirmed using a combination algorithm.

RESULTS

A total of 180 patients with EGC were enrolled from 10 institutions, of which 175 were analyzed. The histopathological depths were M, SM1, SM2, and ≥ MP in 72, 16, 64, and 23 lesions, respectively. Treatment included 92 endoscopic submucosal dissection cases and 83 surgical cases. The overall diagnostic accuracy classified by M-SM1 or SM2-MP was 58.3% for CE, 75.7% for EUS, and 78.9% for the combination of CE and EUS; the latter two were significantly higher than that of CE alone (P < 0.001). The CE, EUS, and combination accuracy rates in 108 differentiated-type lesions were 51.9%, 77.4%, and 79.6%, respectively; the latter two were significantly higher than CE alone (P < 0.001). A significant additive effect of EUS was observed in CE-SM2 low-confidence lesions but not in CE-M-SM1 lesions or in CE-SM2 high-confidence lesions. Among the nine CE findings, irregular surface, submucosal tumor-like elevation, and non-extension signs were significant independent markers of pSM2-MP. Poorly delineated EUS lesions were misdiagnosed.

CONCLUSIONS

EUS provides additional value for differentiated-type and CE-SM2 low-confidence EGCs in diagnosing invasion depth.

CLINICAL REGISTRATION NUMBER

UMIN000025862.

Local recurrence after endoscopic resection of sessile serrated lesions: A multicenter prospective study by the Osaka Gut Forum

BACKGROUND AND AIM

Sessile serrated lesions (SSLs) act as precursors to colorectal cancer, sometimes harbor carcinomas, and are sometimes incompletely resected. We aimed to evaluate local recurrence after endoscopic resection of SSL ≥10 mm.

METHODS

This prospective, single-arm, observational study was performed at eight Japanese tertiary institutions. Colorectal lesions ≥10 mm were resected endoscopically, and the pathological diagnosis was either an SSL or hyperplastic polyp (HP). Follow-up colonoscopy was performed 1 year later, and the local recurrence was evaluated by biopsy.

RESULTS

From October 2018 to September 2021, 104 cases with 123 lesions were registered. Among the pathologically diagnosed 105 SSLs and 18 HPs, 95 and 7 lesions were diagnosed as SSLs and HPs, respectively, by central pathological review. Among the 104 endoscopically diagnosed SSLs, 86 were diagnosed as SSLs, whereas among the 11 endoscopically diagnosed HPs, two were diagnosed as HPs by central pathological review (the rest were SSLs). Among the 95 patients with 113 lesions who underwent follow-up colonoscopy, resection scars were identified in 95 (84%) lesions. Three (3.1%; 95% confidence interval 0.6-8.7%) local recurrences were diagnosed pathologically among 98 pathologically diagnosed SSLs. Two (6%) local recurrences were diagnosed in patients with SSLs ≥20 mm.

CONCLUSIONS

The local recurrence rate after endoscopic resection of SSLs ≥10 mm was 3.1%. Careful follow-up is recommended after endoscopic resection of large SSLs. Endoscopically diagnosed HPs ≥10 mm were sometimes pathologically diagnosed as SSL and should be considered for resection.

Geriatric nutritional risk index as a prognostic indicator in elderly patients with early colorectal cancer undergoing endoscopic submucosal dissection

OBJECTIVES

Data on the long-term outcomes of endoscopic submucosal dissection (ESD) performed in elderly patients with early colorectal cancer (CRC) are limited. We analyzed the prognosis of elderly CRC patients, not only from the viewpoint of treatment curability but also from the patients' baseline physical condition assessed by several indexes.

METHODS

A retrospective analysis of 729 patients aged ≥75 years who underwent ESD for Tis/T1 CRC in 16 institutions was conducted. The patients were classified into three groups based on curability: curative ESD (Group A, n = 582), non-curative ESD with additional surgery (Group B, n = 60), and non-curative ESD without additional surgery (Group C, n = 87). Overall survival (OS) was compared among the groups, and factors associated with reduced OS were investigated.

RESULTS

The median follow-up periods in Groups A, B, and C were 41, 49, and 46 months, respectively (P = 0.62), during which 92 patients died. Two patients (0.3%) in Group A, none (0%) in Group B, and three (3.4%) in Group C died of CRC. Three-year OS rates in Groups A, B, and C were 93.9%, 96.1%, and 90.1%, respectively, without a significant difference (P = 0.07). Multivariate analysis indicated low (<96.3) geriatric nutritional risk index (GNRI) as the sole independent predictor for reduced OS (hazard ratio 3.37; 95% confidence interval 2.18-5.22; P < 0.0001).

CONCLUSIONS

Low GNRI, but not the curability attained by ESD, was independently associated with reduced OS in patients with early CRC aged ≥75 years.

Renal Dysfunction is an Independent Risk Factor for Rebleeding After Endoscopic Hemostasis in Patients with Peptic Ulcer Bleeding

BACKGROUND

Despite the progress in endoscopic hemostasis and pharmacological treatment, the mortality rate of peptic ulcer bleeding remains at 5-10%. Rebleeding after peptic ulcer bleeding is believed to be a risk factor for mortality. This study aimed to evaluate whether renal dysfunction is a predictor of rebleeding after endoscopic hemostasis in patients with peptic ulcer bleeding.

METHODS

In this retrospective study, consecutive patients with peptic ulcer bleeding who underwent endoscopic hemostasis at our Hospital from January 2010 to December 2018 were enrolled. The relationship between rebleeding within 30 days after endoscopic hemostasis and the patients' admission and endoscopic characteristics were analyzed using univariate and multivariate regression models.

RESULTS

Out of 274 patients with peptic ulcer bleeding, 17 (6.2%) patients experienced rebleeding. In the analysis of the patients' admission characteristics, estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2 was an independent risk factor for rebleeding (odds ratio 4.77, 95% confidence interval 1.168-18.211, p = 0.03). Patients with eGFR < 15 mL/min/1.73 m2 with or without hemodialysis had the highest rebleeding rate at 36.8%. With respect to endoscopic characteristics, the rate of rebleeding was associated with combination therapy (p < 0.0001) and active bleeding (p = 0.03).

CONCLUSION

Renal dysfunction might be an independent risk factor for rebleeding after endoscopic hemostasis in patients with peptic ulcer bleeding.

Helicobacter pylori eradication prevents secondary gastric cancer in patients with mild-to-moderate atrophic gastritis

BACKGROUND AND AIM

Whether Helicobacter pylori eradication prevents metachronous recurrence after endoscopic resection (ER) of early gastric cancer remains controversial. This multicenter retrospective study aimed to evaluate the long-term (> 5 years) effects of H. pylori eradication by stratifying patients' baseline degrees of atrophic gastritis.

METHODS

A total of 483 H. pylori-positive patients who had undergone ER for early gastric cancer were divided into two groups-(i) those having undergone successful H. pylori eradication within 1 year after ER (eradicated group, n = 294) and (ii) those with failed or not attempted H. pylori eradication (non-eradicated group, n = 189). The cumulative incidences of metachronous gastric cancer between the two groups were compared for all patients, for patients with mild-to-moderate atrophic gastritis (n = 182), and for patients with severe atrophic gastritis (n = 301).

RESULTS

During a median follow-up of 5.2 years (range 1.1-14.8), metachronous cancer developed in 52 (17.7%) patients in the eradicated group and in 35 (18.5%) patients in the non-eradicated group (P = 0.11, log-rank test). In patients with mild-to-moderate atrophic gastritis (111 and 71 in the eradicated and non-eradicated groups, respectively), the cumulative incidence of metachronous cancer was significantly lower in the eradicated group than that in the non-eradicated group (P = 0.03, log-rank test). However, no significant intergroup difference was observed in patients with severe atrophic gastritis (P = 0.69, log-rank test).

CONCLUSIONS

Helicobacter pylori eradication had a preventive effect on the development of metachronous gastric cancer in patients with mild-to-moderate atrophic gastritis.

Prophylactic clipping not effective in preventing post-polypectomy bleeding for < 20-mm colon polyps: A multicenter, open-label, randomized controlled trial

BACKGROUND AND AIM

Prophylactic clipping (PC) after polypectomy has the potential to prevent post-polypectomy bleeding (PPB). We aimed to evaluate the effectiveness of PC in preventing PPB for < 20-mm polyps.

METHODS

This multicenter, open-label, randomized controlled trial conducted from December 2013 to June 2017 at 10 institutions randomly assigned 1080 patients with < 20-mm colon polyps to the non-PC and PC groups. Allocation factors were institution, antiplatelet drug use, and polyp number. The primary endpoint was differences in PPB rates between the groups. The severity of PPB and post-procedural abdominal symptoms were also investigated. These endpoints in intention-to-treat and per-protocol (PP) analyses were evaluated.

RESULTS

We investigated 1039 patients with 2960 lesions. There was no significant difference between the groups in characteristics including age, sex, hypertension, diabetes, hyperlipidemia, antiplatelet drug use, and lesion characteristics such as type and size. Excluding the clip used in the non-PC group, intraoperative bleeding, and deviation of protocol, 903 patients were investigated in PP analysis. There was no significant difference in the PPB rate between the non-PC and PC groups (2.7% vs 2.3%, P = 0.6973 [intention-to-treat analysis]; 3.0 vs 2.4%, P = 0.7353 [PP analysis]). Severe PPB (≥ grade 3) was similar between the groups. Total procedure time was significantly shorter in the non-PC group than in the PC group (31 vs 36 min, P = 0.0002). Post-procedural abdominal fullness was less common in the non-PC group than in the PC group (20.8% vs 25.6%, P = 0.0833).

CONCLUSION

Prophylactic clipping is not effective in preventing PBB for < 20-mm colon polyps (UMIN000012163).

Effect of anticoagulants on the risk of delayed bleeding after colorectal endoscopic submucosal dissection

Background and study aims  In patients receiving antithrombotic therapy, the risks of delayed bleeding after endoscopic procedures for gastrointestinal neoplasms become a major problem. Few reports have shown the effects of delayed bleeding in patients taking anticoagulants after colorectal endoscopic submucosal dissection (ESD). This study aimed to evaluate the delayed bleeding events after colorectal ESD in patients receiving anticoagulant therapy. Patients and methods  We retrospectively analyzed 87 patients taking anticoagulants who underwent colorectal ESD from April 2012 to December 2017 at 13 Japanese institutions participating in the Osaka Gut Forum. Among these patients, warfarin users were managed with heparin bridge therapy (HBT), continued use of warfarin, a temporary switch to direct oral anticoagulation (DOAC), or withdrawal of warfarin, and DOAC users were managed with DOAC discontinuation with or without HBT. We investigated the occurrence rate of delayed bleeding and compared the rates between warfarin and DOAC users. Results  The delayed bleeding rate was 17.2 % among all patients. The delayed bleeding rate was higher in DOAC users than in warfarin users (23.3 % vs. 11.4 %, P  = 0.14), although no statistically significant difference was observed. In DOAC users, the delayed bleeding rates for dabigatran, rivaroxaban, apixaban, and edoxaban users appeared similar (30 %, 18.2 %, 22.2 %, and 25 %, respectively). The onset of delayed bleeding in both warfarin and DOAC users was late, averaging 6.9 and 9.4 days, respectively. Conclusions  Among patients taking anticoagulants, the risk of delayed bleeding after colorectal ESD was relatively high and the onset of delayed bleeding was late.

Comparison of performances of artificial intelligence versus expert endoscopists for real-time assisted diagnosis of esophageal squamous cell carcinoma (with video)

BACKGROUND AND AIMS

Narrow-band imaging (NBI) is currently regarded as the standard modality for diagnosing esophageal squamous cell carcinoma (SCC). We developed a computerized image-analysis system for diagnosing esophageal SCC by NBI and estimated its performance with video images.

METHODS

Altogether, 23,746 images from 1544 pathologically proven superficial esophageal SCCs and 4587 images from 458 noncancerous and normal tissue were used to construct an artificial intelligence (AI) system. Five- to 9-second video clips from 144 patients captured by NBI or blue-light imaging were used as the validation dataset. These video images were diagnosed by the AI system and 13 board-certified specialists (experts).

RESULTS

The diagnostic process was divided into 2 parts: detection (identify suspicious lesions) and characterization (differentiate cancer from noncancer). The sensitivities, specificities, and accuracies for the detection of SCC were, respectively, 91%, 51%, and 63% for the AI system and 79%, 72%, and 75% for the experts. The sensitivity of the AI system was significantly higher than that of the experts, but its specificity was significantly lower. Sensitivities, specificities, and accuracy for the characterization of SCC were, respectively, 86%, 89%, and 88% for the AI system and 74%, 76%, and 75% for the experts. The receiver operating characteristic curve showed that the AI system had significantly better diagnostic performance than the experts.

CONCLUSIONS

Our AI system showed significantly higher sensitivity for detecting SCC and higher accuracy for characterizing SCC from noncancerous tissue than endoscopic experts.

Classification for invasion depth of esophageal squamous cell carcinoma using a deep neural network compared with experienced endoscopists

BACKGROUND AND AIMS

Cancer invasion depth is a critical factor affecting the choice of treatment in patients with superficial squamous cell carcinoma (SCC). However, the diagnosis of invasion depth is currently subjective and liable to interobserver variability.

METHODS

We developed a deep learning-based artificial intelligence (AI) system based on Single Shot MultiBox Detector architecture for the assessment of superficial esophageal SCC. We obtained endoscopic images from patients with superficial esophageal SCC at our facility between December 2005 and December 2016.

RESULTS

After excluding poor-quality images, 8660 non-magnified endoscopic (non-ME) and 5678 ME images from 804 superficial esophageal SCCs with pathologic proof of cancer invasion depth were used as the training dataset, and 405 non-ME images and 509 ME images from 155 patients were selected for the validation set. Our system showed a sensitivity of 90.1%, specificity of 95.8%, positive predictive value of 99.2%, negative predictive value of 63.9%, and an accuracy of 91.0% for differentiating pathologic mucosal and submucosal microinvasive (SM1) cancers from submucosal deep invasive (SM2/3) cancers. Cancer invasion depth was diagnosed by 16 experienced endoscopists using the same validation set, with an overall sensitivity of 89.8%, specificity of 88.3%, positive predictive value of 97.9%, negative predictive value of 65.5%, and an accuracy of 89.6%.

CONCLUSIONS

This newly developed AI system showed favorable performance for diagnosing invasion depth in patients with superficial esophageal SCC, with comparable performance to experienced endoscopists.

[Anaphylactic shock secondary to the use of macrogol 4000 as a bowel cleanser:a case report]

A 44-year-old man was administered Niflec^® containing macrogol 4000 as a bowel cleanser for colonoscopic examination. Immediately after ingestion, he experienced oral cavity discomfort and nasal congestion, followed by acute urticaria and presyncope. His systolic blood pressure and peripheral capillary oxygen saturation dropped to 66mmHg and 89%, respectively. Fluid infusion, as well as steroid and epinephrine administration, improved his symptoms. Skin prick tests were then performed using Niflec^®, macrogol 4000, and Actosin^® ointment (containing macrogol 4000), all of which were positive. Therefore, the patient was diagnosed with anaphylactic shock caused by macrogol 4000 included in Niflec^®. Macrogol present in bowel cleansers used for colonoscopy rarely causes anaphylactic shock. However, clinicians need to be mindful of this risk. Prompt and appropriate treatment is needed should this condition occur.

[Good Controlled Chylothorax in Gastric Carcinoma]

Chylothorax has been reported to be caused by accidental injuries in half of all cases in Japan, and < 10% of these cases have been associated with malignant tumors, including lymphoma. Chylothorax is a rare complication of gastric carcinoma. We successfully treated a 58-year-old man with gastric carcinoma, chylothorax, and ascites using a combination of talc pleurodesis and a lipid-limited diet. Case: A 58-year-old man with advanced stage of poorly differentiated gastric adenocarcinoma presented to our hospital with complaints of shortness of breath. Whole-body computerized tomographic images suggested massive pleural effusion and ascites. Examination of pleural fluid and ascites revealed elevated serum triacylglycerol levels of up to 913mg/dL with numerous free-floating cancer cells. Malignant chylothorax was diagnosed. A lipid-limited diet and octreotide were started, followed by talc pleurodesis for pleural effusion. The patient with controlled pleurisy died of gastric cancer on day 55 after pleurodesis.

Prophylactic clip closure may reduce the risk of delayed bleeding after colorectal endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) has a high en bloc resection rate and is widely performed for large superficial colorectal tumors, but delayed bleeding remains one of the most common complications of colorectal ESD. The aim of the present study was to evaluate the clinical efficacy of prophylactic clip closure of mucosal defects for the prevention of delayed bleeding after colorectal ESD.

PATIENTS AND METHODS

We enrolled consecutive patients with colorectal lesions between January 2012 and May 2017 in this retrospective study. In the early part of this period, post-ESD mucosal defects were not closed (non-closure group); however, from January 2014, post-ESD mucosal defects were prophylactically closed with clips when possible (closure group). The main outcome measured was delayed bleeding. Variables were analyzed using the chi-squared test, Fisher's exact test, or Student's t-test.

RESULTS

Of 156 lesions analyzed, 61 were in the non-closure group and 95 in the closure group. Overall, delayed bleeding occurred in 5 cases (3.2 %). The delayed bleeding rate was 0 % (0/95) in the closure group and 8.2 % (5/61) in the non-closure group ( P  = 0.008). The mean procedure time for closure was 10.4 ± 4.6 min (range 3 - 26 min).

CONCLUSIONS

We demonstrated that prophylactic clip closure of mucosal defects might reduce the risk of delayed bleeding after colorectal ESD.

Eosinophilia in the muscle layer of the esophagus and the urinary bladder in a Multiple System Atrophy patient with dysphagia and dysuria

Multiple system atrophy (MSA) is a spinocerebellar degenerative disease characterized by cerebellar ataxia, parkinsonism, and autonomic failure. A 75-year-old woman who had suffered from dysphagia and dysuria under a diagnosis of probable MSA with predominant cerebellar ataxia underwent autopsy. Eosinophilia was seen extensively in the muscle layer of the esophagus and urinary bladder. Eosinophilic infiltration to the esophagus was localized in the smooth muscle layer and could be considered as "eosinophilic esophageal myositis" identified in patients with nutcracker esophagus and jackhammer esophagus. Dense eosinophilia was present within the smooth muscle layer of the urinary bladder along with muscle fiber degeneration. We suspected a neuropathic etiology associated with MSA as the cause of the histological changes in the esophagus and urinary bladder; however, the possibility that some other disease might also have been responsible for the eosinophilic infiltration of the muscle layer cannot be denied. To our knowledge, this is the first report showing localized eosinophilia in the muscle layers of the esophagus and urinary bladder in the same patient. Although localized eosinophilia in visceral muscle has not been understood well, our case suggests the possibility that it is a feature of functional motility disorders and may have a neuropathic etiology.

Incidence of gastric adenocarcinoma among lesions diagnosed as low-grade adenoma/dysplasia on endoscopic biopsy: A multicenter, prospective, observational study

BACKGROUND AND AIM

Differentiation between gastric adenocarcinoma and low-grade adenoma/dysplasia (LGA) on endoscopic forceps biopsy is difficult. We aim to clarify the incidence of carcinoma in specimens, obtained by endoscopic resection (ER), from cases that had been diagnosed as LGA (Vienna category 3) on endoscopic biopsy.

METHODS

In this multicenter, prospective, observational study, patients with gastric adenoma (Vienna category 3 or 4.1) diagnosed on endoscopic forceps biopsy were enrolled. All the specimens were subjected to histopathological central review. Primary endpoint was the incidence of carcinoma (Vienna category 4.2 or over) among the biopsy-proven gastric LGA. Secondary endpoints were the histological findings of resected specimens, clinicopathological features of carcinoma, and short-term outcomes of all ER cases.

RESULTS

Ninety-five patients with 104 lesions diagnosed as gastric adenoma were enrolled. After central review of the biopsy specimens, 47 lesions were diagnosed as LGA and seven lesions (15%) as adenocarcinoma (95% confidence interval, 7.6-28%). Carcinoma was detected in lesions that had a minimum size of 6 mm; the incidence of carcinoma was higher in the larger lesions. There was a histological discrepancy between biopsy and ER material in more than 60% of the cases.

CONCLUSIONS

A substantial proportion of biopsy-proven gastric LGA specimens were diagnosed as adenocarcinoma after ER. This indicated histological discrepancy between biopsy-proven gastric LGA and histology of the resected material.

Clinical outcomes of endoscopic submucosal dissection for superficial esophageal neoplasms: a multicenter retrospective cohort study

BACKGROUND AND STUDY AIMS

The safety and efficacy of endoscopic submucosal dissection (ESD) for superficial esophageal neoplasms (SENs) have not been evaluated in a multicenter survey. The aim of this study was to investigate the clinical outcomes in a multicenter study that included municipal hospitals.

PATIENTS AND METHODS

Of 312 consecutive patients with 373 esophageal lesions treated by ESD at 11 hospitals from May 2005 to December 2012, a total of 368 SENs in 307 patients were retrospectively analyzed.

RESULTS

The median tumor size was 18 mm (range 2 - 85 mm). The median procedure time was 90 minutes (range 12 - 450 minutes). The en bloc resection and complete resection rates were 96.7 % (95 % confidence interval [CI] 94.4 % - 98.1 %) and 84.5 % (95 %CI 80.5 % - 87.8 %), respectively. Perforation (including mediastinal emphysema), postoperative pneumonia, bleeding, and esophageal stricture, occurred in 5.2 % (95 %CI 3.3 % - 7.9 %), 1.6 % (95 %CI 0.7 % - 3.5 %), 0 %, and 7.1 % (95 %CI 4.9 % - 10.2 %) of patients, respectively. All of these complications were cured conservatively. No procedure-related mortality occurred. Early treatment periods (odds ratio [OR] = 4.04; P < 0.01) and low volume institutions (OR = 3.03; P  = 0.045) were significantly independent risk factors for perforation. The circumference of the lesion was significantly associated with postoperative stricture (OR = 32.3; P < 0.01). The procedure times significantly decreased in the later period of the study (P < 0.01). Follow-up data (median 35 months; range 4 - 98 months) showed significant differences in overall survival (P = 0.03) and recurrence-free survival (P < 0.01) rates between patients with curative and noncurative resections.

CONCLUSIONS

Esophageal ESD has become feasible with acceptable complication risks and favorable long term outcomes.

Renal dysfunction is an independent risk factor for bleeding after gastric ESD

BACKGROUND AND STUDY AIMS

The number of patients with chronic kidney disease (CKD) is increasing worldwide and gastric cancer sometimes occurs with CKD. However, the safety and feasibility of endoscopic submucosal dissection (ESD) for patients with CKD are not clear. The aim of this study is to clarify the feasibility and safety of gastric ESD for patients with CKD.

PATIENTS AND METHODS

This was a multicenter retrospective cohort study. In total, 144 patients with CKD who underwent gastric ESD between May 2003 and October 2012 were enrolled. The patients were divided into three groups: stage 3 (estimated glomerular filtration rate [eGFR]: 30 - 59 mL/min), stage 4 (eGFR: 15 - 29 mL/min), and stage 5 (eGFR: < 15 mL/min) according to the Kidney Disease Improving Global Outcomes Guidelines. The en bloc and curative resection rates and complications were assessed as short-term outcomes. Overall survival was analyzed using Kaplan - Meier methods.

RESULTS

In total, 92 patients were in stage 3 CKD; 23 in stage 4; and 29 in stage 5, including 19 patients in hemodialysis. The en bloc resection rate was 95.8 %. Post-ESD bleeding was observed in four patients with stage 5 CKD (13.8 %), three with stage 4 (13.0 %), and one with stage 3 (1.1 %). All bleeding could be controlled by endoscopic hemostasis, but five patients required blood transfusion. Perforation occurred in two patients (6.9 %) with stage 5 CKD, none (0 %) with stage 4, and two (4.3 %) with stage 3. Multivariate Poisson regression analysis revealed CKD stage 4 was a critical factor related to bleeding, whereas diabetes mellitus and CKD stage 5, which largely consist of patients receiving hemodialysis, were not. The median observation period of patients who achieved curative resection was 25.9 months (range 0.8-112.7 months) and the 3-year overall survival rate was 92.5 %.

CONCLUSIONS

Estimated GFR is a significant independent predictive factor of post-ESD bleeding in patients with CKD.

Outcomes of ESD for patients with early gastric cancer and comorbid liver cirrhosis: a propensity score analysis

BACKGROUND

Gastric cancer and liver cirrhosis (LC) are often comorbid. However, little is known about the clinical outcomes of gastric endoscopic submucosal dissection (ESD) in patients with comorbid LC.

METHODS

This case-control study used a multicentre retrospective cohort. We identified 69 LC patients from the cohort of patients with early gastric cancer, who underwent gastric ESD at 12 hospitals from March 2003 to November 2010. Using the propensity score matching method, 69 patients without LC were used to compare the short- and long-term outcomes of ESD.

RESULTS

Among the 69 LC patients, 53 (77 %) were Child-Pugh grade A (CP-A) and 16 (28 %) had past or present histories of hepatocellular carcinoma (HCC). Short-term outcomes did not differ between the LC patients and controls or between the CP-A and CP-B/C patients. Although the LC patients had significantly worse long-term outcomes than the controls (the 5-year overall survival rates were 60 vs. 91 %, respectively), patients with CP-A liver function without HCC histories had an overall survival almost equivalent to that of patients without LC (controls).

CONCLUSIONS

LC patients appear to be good candidates for ESD if they have CP-A liver function and no history of HCC. Although their short-term outcomes were not inferior, the patients with Child-Pugh grades B/C or with histories of HCC benefited less from ESD.

Scheduled endoscopic surveillance controls secondary cancer after curative endoscopic resection for early gastric cancer: a multicentre retrospective cohort study by Osaka University ESD study group

BACKGROUND

After endoscopic submucosal dissection (ESD) of early gastric cancer (EGC), patients are at high risk for synchronous or metachronous multiple gastric cancers.

OBJECTIVE

To elucidate the time at which multiple cancers develop and to determine whether scheduled endoscopic surveillance might control their development.

DESIGN

A multicentre retrospective cohort study from 12 hospitals was conducted. Patients with EGC who underwent ESD with en bloc margin-negative curative resection were included. Synchronous cancer was classified as concomitant cancer or missed cancer. The cumulative incidence of metachronous cancers and overall survival rate were calculated using the Kaplan-Meier method.

RESULTS

From April 1999 to December 2010, 1258 patients met the inclusion criteria. Synchronous or metachronous multiple cancers were detected in 175 patients (13.9%) during a mean of 26.8 months. Among the 110 synchronous cancers, 21 were missed at the time of the initial ESD. Many of the missed lesions existed in the upper third of the stomach and the miss rate was associated with the endoscopist's inexperience (<500 oesophagogastroduodenoscopy cases). The cumulative incidence of metachronous cancers increased linearly and the mean annual incidence rate was 3.5%. The incidence rate did not differ between patients with or without Helicobacter pylori eradication. Four lesions (0.32%) were detected as massively invading cancers during the follow-up.

CONCLUSIONS

Nineteen per cent of synchronous cancers were not detected until the initial ESD. The incidence rate of metachronous cancer after ESD was constant. Scheduled endoscopic surveillance showed that almost all recurrent lesions were treatable by endoscopic resection.

Short-term outcomes of endoscopic submucosal dissection (ESD) for early gastric neoplasm: multicenter survey by osaka university ESD study group

BACKGROUND

Endoscopic submucosal dissection (ESD) was developed for en bloc removal of large and flat gastrointestinal tract neoplasms. In Japan, ESD is performed under conscious sedation. The risks for sedation-related complications of ESD, such as postoperative pneumonia, have not been evaluated. The aim of this study was to evaluate the incidence of postoperative pneumonia after ESD in a multicenter survey.

PATIENTS AND METHODS

A total of 1188 patients with upper gastric neoplasms treated with ESD in nine hospitals were enrolled from May 2003 to September 2008. The en bloc resection rates and complications (bleeding, perforation, and postoperative pneumonia) were assessed. The correlations between the clinical variables and complications were investigated using logistic regression models.

RESULTS

The en bloc resection rate was 95.3%. Bleeding, perforation, and pneumonia occurred in 37 (3.1%), 49 (4.1%), and 19 (1.6%) patients, respectively. Univariate analysis indicated that procedure time, but not specimen size, or patient age, or sex, was significantly related to bleeding and perforation. The incidence of pneumonia was higher in patients with ulceration, older patients (≥75years), and those with a long procedure duration (≥5h).

CONCLUSION

The incidence of pneumonia, but not perforation and bleeding, after ESD, is high in older patients (≥75years). Special care should be taken with older patients undergoing ESD to minimize the risk of postoperative pneumonia.

Adiponectin deficiency enhanced the severity of cerulein-induced chronic pancreatitis in mice

BACKGROUND

Adiponectin is recognized as an antiinflammatory and antifibrotic protein derived from adipocytes, and low serum adiponectin levels are present in obesity. Recent studies have highlighted the relationship between obesity and pancreatic diseases. However, the role of adiponectin in chronic pancreatitis remains uncertain. The aim of this study was to determine the effects of adiponectin in chronic pancreatitis.

METHODS

We investigated the effects of adiponectin in experimental chronic pancreatitis by using adiponectin-knockout (APN-KO) mice. Chronic pancreatitis was induced by repeated hourly (6 times) intraperitoneal injections of 50 microg/kg cerulein three times per week for 4 weeks in wild-type (WT) and APN-KO mice. We evaluated the severity of chronic pancreatitis biochemically and morphologically.

RESULTS

In cerulein-treated mice, macroscopically and histologically, severe pancreatic damage was observed in APN-KO mice compared with findings in WT mice. The histological scores for chronic pancreatitis, including glandular atrophy, pseudotubular complex, fibrosis, and total scores, were significantly higher in APN-KO mice than in WT mice. Activated pancreatic stellate cells and F4/80-positive pancreatic macrophages accumulated in the pancreas of APN-KO mice but not in WT mice. Overexpression of the mRNAs of transforming growth factor-beta1, CD68, and monocyte chemoattractant protein-1 was noted in APN-KO mice but not in WT mice. The gene expression level of collagen1 (alpha1) tended to be higher in APN-KO mice than in WT mice, albeit insignificantly.

CONCLUSIONS

Adiponectin deficiency enhanced the severity of cerulein-induced chronic pancreatitis in mice. Hypoadiponectinemia could enhance the severity of chronic pancreatitis.

Endoscopic submucosal dissection for early gastric cancer performed by supervised residents: assessment of feasibility and learning curve

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is feasible as a treatment for early gastric cancer (EGC) when it is performed by an experienced endoscopist. We investigated whether it was feasible for novice endoscopists to perform ESD for EGC, and how difficult it was to learn the procedure.

METHODS

This case series study was performed in a cancer referral center. Three resident endoscopists, who had already learned basic procedures, performed ESD under supervision for 30 consecutive lesions, and their procedures were analyzed. The procedure was divided for assessment into (i) mucosal incision and (ii) submucosal dissection by completion of the circumferential mucosal cut. An insulated-tip knife was used for mucosal incision and submucosal dissection. A total of 90 mucosal EGCs (< or = 2 cm) without ulcers or scars in 87 patients were included. Outcomes were: rates of complete resection, complications, and self-completion; operation time; learning curve; and reasons for change of supervisor as an indicator of difficulty.

RESULTS

Among the 90 procedures, there was a good overall complete resection rate of 93 %, with an acceptable complication rate of 4.4 %; the complications were delayed hemorrhage in two patients, and perforations in another two patients that were repaired successfully by endoscopic clipping. The self-completion rate and operation time were significantly worse for submucosal dissection than for mucosal incision. Two of the three operators showed a flat learning curve for submucosal dissection. Difficulty with the procedure was related mainly to uncontrollable hemorrhage.

CONCLUSIONS

With appropriate supervision, gastric ESD by residents is feasible, with equivalent complete resection rates and acceptable complication rates compared with those of experienced endoscopists, although there was difficulty in achieving sufficient self-completion rates in submucosal dissection. Better control of bleeding during submucosal dissection may be a key to improving the procedure.

Disturbed gastrointestinal motility and decreased interstitial cells of Cajal in diabetic db/db mice

BACKGROUND AND AIM

Diabetes mellitus (DM) often causes gastrointestinal dysmotility. Interstitial cells of Cajal (ICC), which express c-kit receptor tyrosine kinase (KIT), are considered the pacemaker cells for gastrointestinal movement. The present study was designed to determine the role of ICC in the pathogenesis of gastroenteropathy in type 2 DM.

METHODS

We examined C57BL/KsJ-db/db mice as a model for type 2 DM. Gastrointestinal motility was evaluated by measuring gastric emptying, whole gut transit time, and isometric tension of the isolated small intestine. The area of KIT-positive cells in the gastrointestinal tract was examined by image analysis of fluorescent immunohistochemistry. The mRNA expression of KIT ligand, stem cell factor (SCF), in the gastrointestinal tract was quantified by real-time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Compared with 12-week-old db/+m control mice, diabetic db/db mice of the same age exhibited delayed gastric emptying, prolonged whole gut transit time, irregular frequency of isometric tension in the small intestine, smaller areas of KIT-positive cells in the antrum, small intestine, and colon, and lower mRNA expression levels of SCF in the small intestine and colon.

CONCLUSIONS

We demonstrated disturbed gastrointestinal motility in db/db mice with reduced areas of ICC and expression of SCF. Our results suggest the involvement of ICC in the gastroenteropathy of type 2 DM.

Effect of a proton pump inhibitor or an H2-receptor antagonist on prevention of bleeding from ulcer after endoscopic submucosal dissection of early gastric cancer: a prospective randomized controlled trial

OBJECTIVES

With conventional methods of endoscopic mucosal resection for early gastric cancer (EGC), proton pump inhibitors (PPIs) and H2-receptor antagonists (H2RAs) have a similar effect on preventing bleeding from artificial ulcers. An objective of this study is to investigate whether a stronger acid suppressant (i.e., PPI) more effectively prevents bleeding after the recent advanced technique of endoscopic submucosal dissection (ESD) for EGC.

METHODS

This was a prospective randomized controlled trial performed in a referral cancer center. A total of 143 patients with EGC who underwent ESD were randomly assigned to the treatment groups. They received either rabeprazole 20 mg (PPI group) or cimetidine 800 mg (H2RA group) on the day before ESD and continued for 8 wk. The primary end point was the incidence of bleeding that was defined as hematemesis or melena that required endoscopic hemostasis and decreased the hemoglobin count by more than 2 g/dL.

RESULTS

In baseline data, the endoscopists who performed the ESD were significantly different between the groups. Finally, 66 of 73 patients in the PPI group and 64 of 70 in the H2RA group were analyzed. Bleeding occurred in four patients in the PPI group and 11 in the H2RA group (P= 0.057). Multivariate analysis revealed that treatment with the PPI significantly reduced the risk of bleeding: adjusted hazard ratio 0.47, 95% confidence interval 0.22-0.92, P= 0.028. One delayed perforation was experienced in the H2RA group.

CONCLUSIONS

PPI therapy more effectively prevented delayed bleeding from the ulcer created after ESD than did H2RA treatment.

A novel videoendoscopy system by using autofluorescence and reflectance imaging for diagnosis of esophagogastric cancers

BACKGROUND

Image quality of the prior autofluorescence (AF) imaging systems, including the fiber-optic endoscope, was not feasible for general clinical use. The use of AF image alone resulted in low specificity. The objective of the study was to evaluate the resolution and the sensitivity of the novel videoendoscopy system by using AF and reflectance imaging (AFI) in the diagnosis of early esophagogastric cancers.

METHODS

This was a case series study. The setting was a pretreatment examination at a cancer center. Five patients with superficial esophageal cancers (SEC) and 21 patients with 22 early gastric cancers (EGC) were included in the study. The extent of the tumors was diagnosed by white light (WL), AF and chromoendoscopic observations. The main outcome measurement was the diagnostic accuracy of each observation in relation to the histologic mapping as a criterion standard.

RESULTS

Two of 5 SECs (40%) were correctly diagnosed in the WL image and all (100%) in the AF image as purple or magenta color in a green background. EGCs in atrophic mucosa were observed as purple or magenta areas in a green background, while diffuse-type EGCs in fundic mucosa were observed as green areas in a purple background. Of the 22 EGCs, diagnostic accuracy of WL, AF, and chromoendoscopic observations were 36%: 95% CI [16%, 56%], 68%: 95% CI [49%, 88%], and 91%: 95% CI [79%, 100%], respectively. AFI could reveal flat or isochromatic extensions that were not detected in the WL images. The limitations of the study were ulcerations or inflammation that caused overdiagnosis in the AF observation.

CONCLUSIONS

The resolution of the AFI at present is limited, but the image quality was acceptable. The current system of AFI does not equal to chromoendoscopy in sensitivity but has an advantage over standard WL videoendoscopy.