Similarity of oncogenic protein expression in KRASG12D gene delivery-based rat pancreatic cancer model to that of human pancreatic cancer

BACKGROUND

The development of effective therapies and biomarkers for pancreatic cancer is an unmet clinical need. To address this, we have developed an easy-to-use pancreatic cancer rat animal model via pancreas-targeted hydrodynamic gene delivery of human pancreatic cancer-related genes. Our study aimed to determine the molecular similarity between the pancreatic tumor in the rat model and human pancreatic cancer.

METHODS

KRAS^G12D gene-expressing plasmid was delivered to the pancreas of wild type rats via pancreas-targeted hydrodynamic gene delivery as previously reported. Tissue samples were collected at 5 weeks after the first gene delivery. The tumors developed in the rats were assessed for the expression of oncogenic proteins that are involved in human pancreatic cancer development.

RESULTS

The development of a tumor mimicking pancreatic ductal adenocarcinoma was confirmed. The expression levels of Cyclin D1, c-Jun, IL-33, and Zip4 proteins in the tumor were immunohistochemically assessed and the correlation of the proteins was confirmed. The expression pattern showed similarity to that of surgically resected human pancreatic cancer tissues.

CONCLUSIONS

Our study findings showing a similar pattern of oncogenic protein expression in novel KRAS^G12D gene-induced rat pancreatic cancer model and human pancreatic cancer will be useful for establishing novel tumor markers and therapeutic options for pancreatic cancer.

Establishment of a pancreatic cancer animal model using the pancreas-targeted hydrodynamic gene delivery method

This research developed an easy-to-use, reproducible pancreatic cancer animal model utilizing pancreas-targeted hydrodynamic gene delivery to deliver human pancreatic cancer-related genes to the pancreas of wild-type rats. KRAS^G12D-induced pancreatic intraepithelial neoplasia lesions showed malignant transformation in the main pancreatic duct at 4 weeks and developed acinar-to-ductal metaplasia, which led to pancreatic ductal adenocarcinoma within 5 weeks, and the gene combination of KRAS^G12D and YAP enhanced these effects. The repeat hydrodynamic gene delivery of KRAS^G12D + YAP combination at 4 weeks showed acinar-to-ductal metaplasia in all rats and pancreatic ductal adenocarcinoma in 80% of rats 1 week later. Metastatic tumors in the liver, lymph nodes, and subcutaneous lesions and nervous invasion were confirmed. KRAS^G12D and YAP combined transfer contributes to the E- to N-cadherin switch in pancreatic ductal adenocarcinoma cells and to tumor metastases. This pancreatic cancer model will speed up pancreatic cancer research for novel treatments and biomarkers for early diagnosis.

Utility of autologous fecal microbiota transplantation and elucidation of microbiota in diversion colitis

Objectives

Diversion colitis (DC) is an inflammatory disorder caused by interruption of the fecal stream and subsequent nutrient deficiency from luminal bacteria. The utility of fecal microbiota transplantation (FMT) for DC was recently investigated; however, the precise pathogenesis of this condition remains unclear. This study aimed to evaluate the utility of autologous FMT in DC and to determine the related changes in the intestinal microbiota.

Methods

Autologous FMT was performed to reestablish the intestinal microbiota in five patients (average age, 64.6 ± 8.3 years) with DC. They underwent double‐ended colostomy. We assessed the diverted colon by endoscopy and evaluated the microbiota before and after FMT using the 16S rRNA gene sequencing method.

Results

All five patients had mild inflammation (ulcerative colitis endoscopic index of severity [UCEIS] 2–3) in the diverted colon based on the colonoscopic findings. Three patients presented with symptoms, such as tenesmus, mucoid stool, and bloody stool. With FMT treatment, all patients achieved endoscopic remission (UCEIS score of 0 or 1) and symptomatic improvement. We observed a significantly decreased α‐diversity in DC patients compared to healthy controls. The frequency of aerobic bacteria, such as Enterobacteriaceae, in the diverted colon decreased after autologous FMT.

Conclusions

This study was the first to show that the microbiota in the diverted colon was significantly affected by autologous FMT. Since interruption of the fecal stream is central to the development of DC, FMT can be considered a promising treatment.

Methotrexate‐associated proliferative disorder in the lower esophagus extending to the gastroesophageal junction: A case report

A 64‐year‐old woman was receiving oral methotrexate (MTX) for rheumatoid arthritis (RA) for 15 years. She underwent esophagogastroduodenoscopy because of discomfort in the chest. Endoscopic findings revealed an ulcer in the lower esophagus extending to the gastroesophageal junction (EGJ). The ulcer occupied half of the esophageal lumen and had a sharp and clear margin. Magnifying narrow‐band imaging endoscopy revealed the deposition of white plaque, and there were few microvessels in the edge and bottom of the ulcer. Histologic examination of the biopsy specimens from the oral edge of the lesion revealed proliferation of atypical lymphoid cells (immunophenotype results: CD20 [+], CD3 [partially +], CD5 [−], and BCL‐2 [−]]. The patient was diagnosed with methotrexate‐associated lymphoproliferative disorder (MTX‐LPD) and was advised to stop MTX intake. After 2 months of stopping MTX, the ulcer was found to be almost regressed and showed signs of healing. MTX‐LPD in the lower esophagus extending to the EGJ is extremely rare. This case can help in expanding the understanding of esophageal MTX‐LPD.

Rapid decline in visceral adipose tissue over 1 month is associated with poor prognosis in patients with unresectable pancreatic cancer

Background

Involuntary weight loss related to cachexia is common in patients with advanced cancer, but the association between body composition changes and survival is still unclear in pancreatic cancer.

Methods

We retrospectively reviewed the clinical outcomes of 55 patients with advanced pancreatic cancer undergoing palliative therapy or best supportive care (BSC). The skeletal muscle index (SMI), visceral adipose tissue index (VATI), subcutaneous adipose tissue index (SATI), and visceral to subcutaneous adipose tissue area ratio (VSR) were calculated based on the cross‐sectional area on two sets of computed tomography images obtained at cancer diagnosis and 1 month later before treatment. The prognostic value of body composition indexes at diagnosis and the changes in those indexes over 1 month was then evaluated.

Results

In total, 45 patients (81.8%) received chemotherapy, chemoradiation, or radiation therapy, whereas the remaining patients underwent BSC. There were 27 patients (49.1%) who had low SMI at cancer diagnosis. Univariate analysis showed no significant associations between the baseline body composition indexes including SMI, VATI, SATI, and VSR and survival. Meanwhile, male sex (HR, 2.79; 95% CI, 1.16–6.71, p = 0.022) and higher decrease in VATI over 1 month (HR, 2.41; 95% CI, 1.13–5.13, p = 0.023) were identified as independent risk factors for mortality in multivariate analysis.

Conclusion

Rapid decline in VAT over 1 month is closely associated with poorer survival in unresectable advanced pancreatic cancer. A short‐term assessment of body composition changes may be a rational approach to predict prognosis in these patients.

Comparison of Oral and Esophageal Microbiota in Patients with Achalasia Before and After Peroral Endoscopic Myotomy

BACKGROUND/AIMS

Patients with achalasia have a high incidence of esophageal squamous cell carcinoma (ESCC), which may be associated with alterations in oral and esophageal microbiota caused by food stasis. This study compared the oral and esophageal microbiota of patients with achalasia before and after peroral endoscopic myotomy (POEM). It also compared patients with achalasia to those with ESCC.

MATERIALS AND METHODS

The study prospectively examined 6 patients with achalasia and 14 with superficial ESCC. Oral samples obtained from the buccal mucosa using a swab and esophageal samples obtained from the mid-esophagus using a brush via endoscopy were analyzed by 16S rRNA metagenome sequencing. Additionally, endoscopic and histological findings of patients with achalasia before and after POEM were prospectively compared.

RESULTS

In patients with achalasia, Streptococcus was most abundant in both the oral and the esophageal microbiota, and these microbiota were significantly different. Although the overall structure of the oral and esophageal microbiota did not change after POEM, the relative abundance rate of Haemophilus and Neisseria increased in the esophagus, and endoscopic findings of inflammation improved after POEM (P = .04). The relative abundance of microbiota was not different among patients with achalasia from those with ESCC.

CONCLUSIONS

The oral and esophageal microbiota were significantly different in patients with achalasia, and some of the composition of the esophageal microbiota changed after POEM. However, these findings and disease-specific microbiota should be further evaluated in large-scale studies.

Evaluation of intestinal microbiota, short-chain fatty acids, and immunoglobulin a in diversion colitis

It is reported that an increase in aerobic bacteria, a lack of short-chain fatty acids (SCFAs), and immune disorders in the diverted colon are major causes of diversion colitis. However, the precise pathogenesis of this condition remains unclear. The aim of the present study was to examine the microbiota, intestinal SCFAs, and immunoglobulin A (IgA) in the diverted colon. Eight patients underwent operative procedures for colostomies. We assessed the diverted colon using endoscopy and obtained intestinal samples from the diverted colon and oral colon in these patients. We analyzed the microbiota and SCFAs of the intestinal samples. The bacterial communities were investigated using a 16S rRNA gene sequencing method. The microbiota demonstrated a change in the proportion of some species, especially Lactobacillus, which significantly decreased in the diverted colon at the genus level. We also showed that intestinal SCFA values were significantly decreased in the diverted colon. Furthermore, intestinal IgA levels were significantly increased in the diverted colon. This study was the first to show that intestinal SCFAs were significantly decreased and intestinal IgA was significantly increased in the diverted colon. Our data suggest that SCFAs affect the microbiota and may play an immunological role in diversion colitis.

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Anaerobic bacteria like Lactobacillus significantly decreased in the diverted colon.

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Fecal short-chain fatty acids significantly decreased in the diverted colon.

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Acetic acid also decreased significantly in the diverted colon.

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Fecal immunoglobulin A levels were significantly increased in the diverted colon.

Choledochocele observed on direct peroral cholangioscopy using an ultra-slim endoscope

Highlight Ikarashi and colleagues report a case of choledococele treated by endoscopic sphincterotomy and observed on direct peroral cholangioscopy. Histological examination reveals duodenum-like mucosa without atypical changes in the choledochocele. Direct peroral cholangioscopy using an ultra-slim endoscope may be a useful technique for diagnosis and surveillance of choledochocele.

Usefulness of ultrasonography to assess the response to steroidal therapy for the rare case of type 2b immunoglobulin G4-related sclerosing cholangitis without pancreatitis: A case report

BACKGROUND

A type 2b immunoglobulin G4 (IgG4)-related sclerosing cholangitis (SC) without autoimmune pancreatitis is a rare condition with IgG4-SC. While the variety of the imaging modalities have tested its usefulness in diagnosing the IgG4-SC, however, the usage of ultrasonography for the assessment of the response to steroidal therapy on the changes of bile duct wall thickness have not been reported in the condition. Therefore, the information of our recent case and reported cases have been summarized.

CASE SUMMARY

We report the case of an 82-year-old Japanese man diagnosed with isolated IgG4-related SC based on the increase of serum IgG4, narrowing of the bile duct, its wall thickness, no complication of autoimmune pancreatitis, and IgG4 positive inflammatory cell infiltration to the wall with the fibrotic changes. The cholangiogram revealed type 2b according to the classification. Corticosteroid treatment showed a favorable effect, with the smooth decrease in serum IgG4 and the improvement of the bile duct wall thickness.

CONCLUSION

As isolated type 2b, IgG4-SC is rare, the images, histological findings, and clinical course of our case will be helpful for physicians to diagnose and treat the new cases appropriately.

Effectiveness of Endoscopic Pancreatic Stenting for Pancreatic Pseudocyst-Portal Vein Fistula

Pancreatic pseudocyst-portal vein (PP-PV) fistula, mostly occurring after pseudocyst formation following acute/chronic pancreatitis, is a rare but life-threatening condition. The majority of treatments are based on conservative or surgical interventions. We report the case of a 70-year-old man with a PP-PV fistula and PV thrombosis. We adopted conservative treatment at first due to his mild symptoms. However, after resuming food intake, the patient had severe abdominal pain. Following endoscopic retrograde cholangiopancreatography, we found that the pseudocyst was connected with the PV through the fistula. Subsequently, an endoscopic nasopancreatic drainage (ENPD) catheter was inserted into the main pancreatic duct to establish pancreatic drainage, which resulted in a decrease in the abdominal pain. After the ENPD tube had been exchanged for endoscopic pancreatic stenting, his abdominal pain did not recur. Therefore, this case demonstrated endoscopic treatment as an effective treatment option for PP-PV fistula.

Risk factors for walled-off necrosis associated with severe acute pancreatitis: A multicenter retrospective observational study

BACKGROUND

This study aimed to identify the risk factors for walled-off necrosis (WON) associated with severe acute pancreatitis (SAP).

METHODS

This retrospective study was conducted in eight institutions in Japan between 2014 and 2017. We analyzed WON incidence, patient characteristics, and risk factors for WON in patients with SAP who were observed for >28 days.

RESULTS

Of 134 patients with SAP, WON occurred in 40 (29.9%). Male sex (P = .045), body mass index (BMI) ≥25 (P < .001), post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (P = .020), and disseminated intravascular coagulation (DIC) (P = .001) were more frequent in the WON group than in the non-WON group. On admission, the frequency of white blood cell counts ≥ 12 000/µL (P = .037) and hypoenhanced pancreatic lesion on computed tomography (P = .047) were significantly higher in the WON group. In multivariate analysis, BMI ≥ 25 (odds ratio [OR] 5.73, 95% confidence interval [CI] 1.95-16.8; P = .002), post-ERCP (OR 8.08, 95% CI 1.57-41.7; P = .013), and DIC (OR 3.52, 95% CI 1.20-10.4; P = .022) were independent risk factors for WON.

CONCLUSIONS

High BMI, post-ERCP pancreatitis, and DIC are risk factors for the development of WON associated with SAP.

Change in body composition in patients with achalasia before and after peroral endoscopic myotomy

BACKGROUND AND AIM

Patients with achalasia experience weight loss because of dysphagia caused by impaired relaxation of the lower esophageal sphincter. This study aimed to use dual bioelectrical impedance analysis (BIA) to determine the change in bodyweight and body composition in patients with achalasia before and after peroral endoscopic myotomy (POEM).

METHODS

Patients with achalasia who underwent POEM from 2013 to 2018 (n = 72) were retrospectively analyzed for change in bodyweight before and after 3 months. Additionally, change in body composition was prospectively investigated in the final 10 of 72 patients using non-radiation dual BIA.

RESULTS

Twenty patients (27.8%) were underweight (body mass index < 18.5) before undergoing POEM. No clinical parameters were identified to be associated with the underweight condition before POEM and be predictive of an increase in bodyweight after POEM. Low visceral fat volume observed on dual BIA correlated closely with the result obtained using computed tomography (Pearson correlation coefficient: r = 0.850, P < 0.01). Patients with achalasia had a statistically significant increase in visceral (P < 0.01) and subcutaneous fat volumes (P < 0.01) after POEM. Skeletal muscle mass index slightly increased (P = 0.02), although the value after POEM was still low. No blood biomarkers were indicators for low bodyweight or low visceral fat volume.

CONCLUSIONS

Dual BIA is an effective non-invasive tool to evaluate the change in body composition of underweight patients with achalasia. Skeletal muscle volume was not enough after POEM, although a rapid increase in the intra-abdominal fat volume was observed. Additional studies are warranted to understand the pathological implications.

Management decision based on lymphovascular involvement leads to favorable outcomes after endoscopic treatment of esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) invading the muscularis mucosae (MM) and submucosa up to 200 µm (SM1) has a risk of metastasis. The aims of this study were to investigate the long-term outcome of endoscopic submucosal dissection (ESD) for MM/SM1 ESCC and to assess the management after ESD in our hospital.

METHODS

This was a retrospective cohort study conducted at a single institution. Patients with MM or SM1 ESCC who were treated with ESD were included. Additional prophylactic therapy was added if lymphovascular involvement (LVI) was noted in the ESD specimens.

RESULTS

A total of 102 patients were analyzed. The median length of follow-up was 71.5 months (range 9 - 144 months) and the median number of CTs was 6 (range 0 - 24). LVI was found in 21 patients (20.6 %), and 12 patients underwent additional prophylactic therapy. The 5-year overall survival, disease-specific survival, and tumor-free survival rates were 84.1 %, 97.5 %, and 82.1 %, respectively. A total of 26 patients died, but only 2 of them died from ESCC. The cumulative metastasis rate was 11.8 %, and LVI was a significant predictor of metastasis (hazard ratio 5.42, 95 % confidence interval 1.39 - 21.18; P = 0.02). There were no differences between patients with MM ESCC and those with SM1 ESCC.

CONCLUSIONS

The long-term outcome after ESD for MM/SM1 ESCC was favorable with additional prophylactic therapy and strict adherence to follow-up. These results indicate that our management decision based on LVI is a valid approach and that ESD can be offered as a therapeutic option to MM/SM1 ESCCs.

A Case of Pancreatic Schwannoma Diagnosed Preoperatively by Endoscopic Ultrasonography-Guided Fine Needle Aspiration and Treated with Laparoscopic Surgery

Background: Pancreatic tumors are often difficult to diagnose in atypical cases, and a pancreatic schwannoma is very rare. We present a case of pancreatic schwannoma with calcification diagnosed preoperatively by endoscopic ultrasonography (EUS)-guided fine needle aspiration (FNA) and treated with laparoscopic distal pancreatectomy.

Presentation: A 72-year-old-woman was admitted to our hospital due to a 6 × 4.5 cm large tumor in the pancreatic tail. Imaging modalities revealed that the tumor was hypovascular and gradually enhanced with calcification, but was without cystic lesions. EUS revealed the tumor had a clear boundary with a low echoic mass. EUS-FNA was performed and spindle-shaped cells that were immunopositive for S-100 and negative for c-kit, CD34, and desmin were detected, resulting in a diagnosis of schwannoma. Laparoscopic distal pancreatectomy with splenectomy was safely performed without recurrence for a year.

Conclusions: Schwannoma is very rare; however, characteristics of the tumor, such as calcification, can help the diagnosis and, if possible, EUS-FNA should be performed for an appropriate treatment decision.

Full-layer mucosal histology in achalasia: Histological epithelial wave is characteristic in "pinstripe pattern"-positive achalasia

BACKGROUND

Previously, the mucosal histology in achalasia has only been investigated using superficial biopsy or surgically resected esophageal specimens in end-stage cases. We investigated the histology of the full-layer mucosa in early and advanced achalasia.

METHODS

Endoscopy was performed for the pinstripe pattern (PSP) (an early achalasia indicator) and dilation and thickening of the mucosa (advanced achalasia indicators). A mucosal entry site for peroral endoscopic myotomy was created using cap-fitted endoscopic mucosal resection to access the full-layer mucosa and the submucosa.

KEY RESULTS

Mucosal histology was compared between 32 patients with achalasia and 15 controls. Histological esophagitis with findings of inflammatory cell infiltration and dilated intercellular spaces was observed more in patients with achalasia than in controls (87.5% vs 13.3%, P<.001; 84.4% vs 46.7%, P=.049). Muscularis mucosae (MM) atrophy and epithelial wave were only observed in achalasia (40.6% vs 0%, P=.005; 28.1% vs 0%, P=.043). Fibrosis was more common in achalasia, but without statistical significance (31.3% vs 20.0%, P=.503). In achalasia with endoscopic dilation and thickening of the mucosa, MM atrophy was observed histologically, and in cases involving endoscopic PSP, the histological epithelial wave was observed.

CONCLUSIONS & INFERENCES

Histological findings of esophagitis were observed endoscopically even in early achalasia. Pinstripe pattern corresponds to the epithelial wave observed histologically in achalasia, whereas endoscopic findings in advanced achalasia correspond to MM atrophy. Appropriate management is necessary during early achalasia to prevent progression to advanced achalasia with more severe histological changes.

Endoscopic ultrasound-guided fine-needle aspiration for diagnosing a rare extraluminal duodenal gastrointestinal tumor

Duodenal gastrointestinal stromal tumors (GISTs) are extremely rare disease entities, and the extraluminal type is difficult to diagnose. These tumors have been misdiagnosed as pancreatic tumors; hence, pancreaticoduodenectomy has been performed, although partial duodenectomy can be performed if accurately diagnosed. Developing a diagnostic methodology including endoscopic ultrasonography (EUS) and fine-needle aspiration (FNA) has allowed us to diagnose the tumor directly through the duodenum. Here, we present a case of a 50-year-old woman with a 27-mm diameter tumor in the pancreatic uncus on computed tomography scan. EUS showed a well-defined hypoechoic mass in the pancreatic uncus that connected to the duodenal proper muscular layer and was followed by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Histological examination showed spindle-shaped tumor cells positively stained for c-kit. Based on these findings, the tumor was finally diagnosed as a duodenal GIST of the extraluminal type, and the patient underwent successful mass resection with partial resection of the duodenum. This case suggests that EUS and EUS-FNA are effective for diagnosing the extraluminal type of duodenal GISTs, which is difficult to differentiate from pancreatic head tumor, and for performing the correct surgical procedure.

Changes in esophageal motility after endoscopic submucosal dissection for superficial esophageal cancer: a high-resolution manometry study

The effect of endoscopic submucosal dissection (ESD) on esophageal motility remains unknown. Therefore, the aim of this study is to elucidate changes in esophageal motility after ESD along with the cause of dysphagia using high-resolution manometry (HRM). This is a before-and-after trial of the effect of ESD on the esophageal motility. Twenty patients who underwent ESD for superficial esophageal carcinoma were enrolled in this study. Patients filled out a questionnaire about dysphagia and underwent HRM before and after ESD. Results before and after ESD were compared. Data were obtained from 19 patients. The number of patients who complained of dysphagia before and after ESD was 1/19 (5.3%) and 6/19 (31.6%), respectively (P = 0.131). Scores from the five-point Likert scale before and after ESD were 0.1 ± 0.5 and 1.0 ± 1.6, respectively (P = 0.043). The distal contractile integral (DCI) before and after ESD and the number of failed, weak, or fragmented contractions were not significantly different. However, in five patients with circumferential ESD, DCI was remarkably decreased and the frequency of fail, weak, or fragmented contractions increased. Univariate regression analysis showed a relatively strong inverse correlation of ΔDCI with the circumferential mucosal defect ratio {P < 0.01, standardized regression coefficient (r) = -0.65}, the number of stricture preventions (P < 0.01, r = -0.601), and the number of stricture resolutions (P < 0.01, r = -0.77). This HRM study showed that impairment of esophageal motility could be caused by ESD. The impairment of esophageal motility was conspicuous, especially in patients with circumferential ESD and subsequent procedures such as endoscopic triamcinolone injection and endoscopic balloon dilatation. Impaired esophageal motility after ESD might explain dysphagia.

Proposed criteria to differentiate heterogeneous eosinophilic gastrointestinal disorders of the esophagus, including eosinophilic esophageal myositis

AIM

To define clinical criteria to differentiate eosinophilic gastrointestinal disorder (EoGD) in the esophagus.

METHODS

Our criteria were defined based on the analyses of the clinical presentation of eosinophilic esophagitis (EoE), subepithelial eosinophilic esophagitis (sEoE) and eosinophilic esophageal myositis (EoEM), identified by endoscopy, manometry and serum immunoglobulin E levels (s-IgE), in combination with histological and polymerase chain reaction analyses on esophageal tissue samples.

RESULTS

In five patients with EoE, endoscopy revealed longitudinal furrows and white plaques in all, and fixed rings in two. In one patient with sEoE and four with EoEM, endoscopy showed luminal compression only. Using manometry, failed peristalsis was observed in patients with EoE and sEoE with some variation, while EoEM was associated with hypercontractile or hypertensive peristalsis, with elevated s-IgE. Histology revealed the following eosinophils per high-power field values. EoE = 41.4 ± 7.9 in the epithelium and 2.3 ± 1.5 in the subepithelium; sEoE = 3 in the epithelium and 35 in the subepithelium (conventional biopsy); EoEM = none in the epithelium, 10.7 ± 11.7 in the subepithelium (conventional biopsy or endoscopic mucosal resection) and 46.8 ± 16.5 in the muscularis propria (peroral esophageal muscle biopsy). Presence of dilated epithelial intercellular space and downward papillae elongation were specific to EoE. Eotaxin-3, IL-5 and IL-13 were overexpressed in EoE.

CONCLUSION

Based on clinical and histological data, we identified criteria, which differentiated between EoE, sEoE and EoEM, and reflected a different pathogenesis between these esophageal EoGDs.

Development and use of a non-biomaterial model for hands-on training of endoscopic procedures

BACKGROUND

Endoscopic submucosal dissection (ESD) and peroral endoscopic myotomy (POEM) are recently developed techniques that have the potential to significantly improve clinical outcomes. However, training opportunities on these techniques remain limited. To address this issue, we developed a novel ex-vivo ESD/POEM training model. Our aim in this paper is to describe the model and provide preliminary evidence of promising feasibility to improve access to ESD/POEM training.

METHODS

The model was developed using polyvinyl alcohol hydrogel, which can easily be modified to reproduce the stiffness of the different intestinal layers, namely the mucosa, submucosa, and muscle layer.

RESULTS

A training workshop, using our ex-vivo model, was held for 28 residents. Satisfaction and feasibility in using the ex-vivo model for endoscopic training were evaluated by using a self-report questionnaire. All participants were satisfied with their training experience (100% satisfaction rate), with 27 of the 28 participants reporting that the model was feasible in replicating all components of the ESD/POEM technique (96.4% feasibility rate).

CONCLUSIONS

Based on this feedback, we propose that our non-biomaterial model has the feasibility to provide an effective endoscopy education tool and a satisfactory training experience.

Early Detection of Hepatocellular Carcinoma Recurrence Using the Highly Sensitive Fucosylated Fraction of Alpha-Fetoprotein

Alpha-fetoprotein (AFP)-L3 was originally reported as a hepatocellular carcinoma (HCC)-specific tumor marker, and recent accumulation of evidence has revealed that AFP-L3 frequency predicts the biological malignancy potential of HCC. However, AFP-L3 elevation from undetectable levels after curative treatment could not be discussed due to the difficulties of calculating AFP-L3 concentrations when serum AFP levels were low. Here, as a novel method, we used highly sensitive AFP-L3 frequency to predict HCC recurrence after curative treatment. Our cases illustrate that recognizing elevation of AFP-L3 from undetectable levels led to the early detection of recurrent HCC due to more careful surveillance.

Short-type single-balloon enteroscope-assisted ERCP in postsurgical altered anatomy: potential factors affecting procedural failure

Background and study aims Short-type single-balloon enteroscope (short SBE)-assisted endoscopic retrograde cholangiopancreatography (ERCP) is a promising alternative treatment in postsurgical altered anatomy. However, it is technically demanding, and factors affecting its technical difficulty have not yet been clarified. This study aimed to examine the procedural success rate of short SBE-assisted ERCP and the potential factors affecting procedural failure. Patients and methods A total of 117 consecutive patients (203 procedures) with surgically altered anatomy underwent ERCP using prototype short SBEs. The procedural success rate of short SBE-assisted ERCP and the potential factors affecting procedural failure were examined retrospectively. Results The enteroscopy success rate and procedural success rate were 92.6 % (95 % confidence interval [CI] 88.1 % - 95.8 %) and 81.8 % (95 %CI 75.8 % - 86.8 %), respectively. Multivariate analyses indicated that pancreatic indication (odds ratio [OR] 4.35, 95 %CI 1.67 - 11.4), first ERCP attempt (OR 6.03, 95 %CI 2.17 - 16.8), and no transparent hood (OR 4.61, 95 %CI 1.48 - 14.3) were potential risk factors for procedural failure. Conclusions Short SBE-assisted ERCP was effective in postsurgical altered anatomy. This large case series suggested the potential factors affecting procedural failure.

Pancreatic Metastasis from Rectal Cancer that was Diagnosed by Endoscopic Ultrasonography-guided Fine Needle Aspiration (EUS-FNA)

Pancreatic metastasis from colorectal cancer is rare, and there have been only a few reports of its preoperative diagnosis by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with immunohistochemical staining. We herein describe the case of a 77-year-old woman in whom a solitary mass in the pancreatic tail was detected 11 years after rectal cancer resection. The patient also had a history of pulmonary tumor resection. We performed EUS-FNA and a histopathological examination showed adenocarcinoma with CD20+, CD7-, and CDX2+ (similar to her rectal cancer). EUS-FNA enabled a histopathological examination, including immunohistochemical staining, which helped to confirm the diagnosis of pancreatic and pulmonary metastasis from rectal cancer.

Resected tumor seeding in stomach wall due to endoscopic ultrasonography-guided fine needle aspiration of pancreatic adenocarcinoma

Endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) is a useful and relatively safe tool for the diagnosis and staging of pancreatic cancer. However, there have recently been several reports of tumor seeding after EUS-FNA of adenocarcinomas. A 78-year-old man was admitted to our hospital due to upper gastric pain. Examinations revealed a 20 mm mass in the pancreatic body, for which EUS-FNA was performed. The cytology of the lesion was adenocarcinoma, and the stage of the cancer was T3N0M0. The patient underwent surgery with curative intent, followed by adjuvant chemotherapy with S-1. An enlarging gastric submucosal tumor was found on gastroscopy at 28 mo after surgery accompanied by a rising level of CA19-9. Biopsy result was adenocarcinoma, consistent with a pancreatic primary tumor. Tumor seeding after EUS-FNA was strongly suspected. The patient underwent surgical resection of the gastric tumor with curative intent. The pathological result of the resected gastric specimen was adenocarcinoma with a perfectly matched mucin special stain result with the previously resected pancreatic cancer. This is the first case report of tumor seeding after EUS-FNA which was surgically resected and inspected pathologically.

Bench-top testing of suction forces generated through endoscopic ultrasound-guided aspiration needles

BACKGROUND

Adequate needle size and tissue acquisition techniques for endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) need further elucidation. Moreover, the actual negative pressure and suction forces of FNA needles remain unknown. We evaluated the suction forces of 19-gauge, 22-gauge, and 25-gauge conventional FNA needles and side hole aspiration needles using conventional negative pressure and the slow pull technique.

METHODS

Using a manometer, we determined the mean (SD) negative pressure and suction force for needle gauge, aspiration volume, and aspiration technique. We also evaluated the time to reach the maximum negative pressure.

RESULTS

Suction force was comparatively higher in the 19-gauge needle when 50 ml of negative pressure was applied. Suction force using the slow pull method was very weak at 5% of pressure found with conventional methods. With the use of a 20-ml syringe, the time to reach the maximum negative pressure was 4 s in the 19-gauge needle, 11 s in the 22-gauge needle, and 80 s in the 25-gauge needle.

CONCLUSIONS

Bench-top testing showed that suction force increases with a larger gauge needle and larger aspiration volume. The slow pull method produces a very weak suction force. The time to reach the maximum negative pressure was longest in the 25-gauge needle.

Long-term outcomes of endoscopic papillary balloon dilation and endoscopic sphincterotomy for bile duct stones

AIM

We recently reported that endoscopic papillary balloon dilation (EPBD) might suppress biliary bacterial contamination better than endoscopic sphincterotomy (EST) in patients with small bile duct stones (diameter ≤8 mm). In the present study, we evaluated immediate and long-term outcomes of endoscopic papillary balloon dilation with regard to stone size.

METHODS

We allocated 474 patients alternately to the two procedures. The patients were classified according to stone diameter (≤8 mm or >8 mm) and outcomes (i.e. complete stone removal, early complications, and late complications) were compared. The predictive risk factors for late complications were also investigated.

RESULTS

In patients with small stones, complete stone removal rate and early complication rate were similar between the two procedures; the incidence of pancreatitis was higher after EPBD, although the difference was not significant. Late complication rate and stone recurrence rate were significantly lower after EPBD than after EST (5.3% vs 17.3%, P = 0.009; 4.4% vs 12.7%; P = 0.048, respectively). In patients with large stones who underwent EPBD complete stone removal rate and late complication rate were lower, but the incidence of pancreatitis was higher. However, these differences were not statistically significant. Multivariate analysis showed that the increased risk of bactobilia following EPBD for large stones or EST, and the gallbladder with stones in situ were independent risk factors for late complications.

CONCLUSIONS

EPBD produced significantly better long-term outcomes than EST in patients with small bile duct stones.

[A case of advanced gastric cancer successfully treated by combination therapy of S-1 and docetaxel]

A 70-year-old man with gastric cancer of Borrmann type 3, liver metastases and peritoneal dissemination was treated by combination therapy of S-1 and docetaxel (DOC). He received DOC intravenously at 40 mg/m(2) on day 1 and S-1 orally at 100 mg/body on day 1 to 14, repeated every 28 days. After 2 courses of treatment, a CT scan revealed improvement of the gastric wall thickness, the eminent decrease of the peritoneal fluid and the reduction of the liver metastasis. After 3 courses of treatment, the primary lesion was remarkably improved on endoscopic examination, and the tumor marker normalized after 4 courses of treatment. Toxicities included leukocytopenia (WHO grade 3), neutropenia ( grade 3), anorexia (grade 2), and nausea (grade 2). Outpatient chemotherapy was possible by reduction of dose (S-1 100--> 80 mg/body, DOC 40--> 32 mg/m2). The response was maintained on CT and endoscopic examination after 21 courses of treatment. A case of an advanced gastric cancer patient successfully treated by combination therapy of S-1 and DOC was reported.