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Isothermal phase equilibrium relations of the CO2 + 1,1,1,2-tetrafluoroethane (HFC-134a) and CO2 + 1,1-difluoroethane (HFC-152a) mixed-gas hydrate systems were measured at 279.15 K. The isothermal phase equilibria of the CO2 + HFC-134a mixed-gas hydrate system exhibit the heterogeneous azeotropic-like behavior derived from the structural phase transition of the mixed-gas hydrate. The CO2 + HFC-152a mixed-gas hydrate system shows neither a structural phase transition nor azeotropic-like behavior.

Background and aim The significance of examination time of esophagogastroduodenoscopy (EGD) for asymptomatic examinees is yet to be established. We aimed to clarify whether endoscopists who allot more examination time can detect higher numbers of neoplastic lesions among asymptomatic examinees. Methods We reviewed a database of consecutive examinees who underwent EGD in our hospital from April 2010 to September 2015. Staff endoscopists were classified into fast, moderate, and slow groups based on the mean examination time of EGD without a biopsy. The neoplastic lesion detection rate among these groups was compared using multiple logistic regression. Results Of the 55,786 consecutive examinees who underwent EGD, 15,763 asymptomatic examinees who were screened by staff doctors were analyzed. The mean examination time of 13,661 EGDs without biopsy was 6.2 min (range, 2–18 min). When cutoffs of 5 and 7 min were used, 4 endoscopists were classified into the fast (mean duration, 4.4 ± 1.0 min), 12 into the moderate (6.1 ± 1.4 min), and 4 into the slow groups (7.8 ± 1.9 min). The neoplastic lesion detection rates in the fast, moderate, and slow groups were 0.57% (13/2,288), 0.97% (99/10,180), and 0.94% (31/3,295), respectively. Compared with that in the fast group, the odds ratios for the neoplastic lesion detection rate in the moderate and slow groups were 1.90 (95% confidence interval [CI], 1.06–3.40) and 1.89 (95% CI, 0.98–3.64), respectively. Conclusion Endoscopists who do not allot adequate examination time may overlook neoplastic lesions in the upper gastrointestinal tract. This article is protected by copyright. All rights reserved.

The optimal regimen of radiotherapy (RT) for bleeding from gastric cancer (GC) has not yet been established. The aim of this study was to evaluate the usefulness of low-dose, short-course palliative RT (LSP-RT) for bleeding from GC.We reviewed the clinical data of 18 patients (26 courses) who received palliative RT for bleeding from GC between 2004 and 2014. The radiation dose was 6 Gy in three fractions. The total courses of RT for each patient were 1-4 (median, 1).The treatment success rate of the first and the additional RT at two weeks after RT was 55% and 75%, respectively. Regarding first RT, there was a statistically significant increase in the mean hemoglobin level for one month (p = 0.009) and a significant decrease in the mean number of transfused red blood cell units for one month (p = 0.012). Toxicities were observed in two patients: one patient who received chemotherapy developed grade 3 afebrile leukocytopenia and another who had a malignant stricture suffered from a gastric obstruction. The performance status was improved in 3 of the 12 evaluable patients (25%) and dietary intake became possible one month after RT in three of the four patients who had not been able to eat before RT.LSP-RT is expected to be not only an effective and safe treatment option for bleeding from GC, but also repeatable in cases of rebleeding. Furthermore, this treatment modality may be able to improve the patient's quality of life.

This retrospective study aimed to clarify the clinical characteristics of advanced colorectal neoplasms after colonoscopy, likely to have been missed on the previous colonoscopy. We reviewed a total of 5,768 consecutive colonoscopies performed from April 2010 to September 2013 in 4,841 patients, and analyzed advanced colorectal neoplasms after colonoscopy, particularly focusing on their morphological characteristics and locations, as compared with primary lesions, defined as lesions detected in their first colonoscopy or in a subsequent colonoscopy5 years after the previous one. Of the 5,768 examinations, 922 advanced neoplasms (including 217 cancers with ≥T2) were detected, and 167 lesions (18.1%) were diagnosed within 5 years after a previous colonoscopy (post-colonoscopy advanced neoplasms). The incidence of right-sided lesions in the post-colonoscopy advanced neoplasms (48.5%, 81/167) was significantly higher than in the primary lesions (34.0%, 257/755; p0.001). We excluded 217 cancers with ≥T2 from the morphological analysis to characterize early-stage post-colonoscopy advanced neoplasms. The incidence of non-polypoid lesions in the post-colonoscopy advanced neoplasms (25.6%, 41/160) was significantly higher than that in the primary lesions (12.3%, 67/545; p0.001). These findings suggest that extra attention should be paid to non-polypoid, right-sided advanced colorectal neoplasms during screening and surveillance colonoscopy. J. Med. Invest. 63: 163-170, August, 2016.

Background and study aims: An iincreasing number of reports describe endoscopic ultrasound-guided hepaticogastrostomy for malignant biliary obstruction in patients with endoscopic retrograde cholangiopancreatography failure. However, this procedure has not yet been standardized; as a result, the rate of adverse events, including bile leakage and stent migration, is relatively high. Here, we report our experience with four cases of endoscopic ultrasound-guided hepaticogastrostomy performed according to our institutional procedure.

Isothermal three-phase equilibria of gas, aqueous, and hydrate phases for the {xenon (Xe) + cyclopropane ( c -C 3 H 6 )} mixed-gas hydrate system were measured at two different temperatures (279.15 and 289.15) K. The structural phase transitions from structure-I to structure-II and back to structure-I, depending on the mole fraction of guest mixtures, occur in the (Xe + c- C 3 H 6 ) mixed-gas hydrate system. The isothermal pressure–composition relations have two local pressure minima. The most important characteristic in the (Xe + c -C 3 H 6 ) mixed-gas hydrate system is that the equilibrium pressure–composition relations exhibit the complex phase behavior involving two structural phase transitions and two homogeneous negative azeotropes. One of two structural phase transitions exhibits the heterogeneous azeotropic-like behavior.

Isothermal phase equilibria (pressure-composition relations in hydrate, gas, and aqueous phases) in the {difluoromethane (HFC-32) + 1,1,1,2-tetrafluoroethane (HFC-134a)} mixed-gas hydrate system were measured at the temperatures 274.15 K, 279.15 K, and 283.15 K. The heterogeneous azeotropic-like behaviour derived from the structural phase transition of (HFC-32 + HFC-134a) mixed-gas hydrates appears over the whole temperature range of the present study. In addition to the heterogeneous azeotropic-like behaviour, the isothermal phase equilibrium curves of the (HFC-32 + HFC-134a) mixed-gas hydrate system exhibit the negative homogeneous azeotropic-like behaviour at temperatures 279.15 K and 283.15 K. The negative azeotropic-like behaviour, which becomes more remarkable at higher temperatures, results in the lower equilibrium pressure of (HFC-32 + HFC-134a) mixed-gas hydrates than those of both simple HFC-32 and HFC-134a hydrates. Although the HFC-134a molecule forms the simple structure-II hydrate at the temperatures, the present findings reveal that HFC-134a molecules occupy a part of the large cages of the structure-I mixed-gas hydrate.

Background. Endoscopic resection (ER) for early gastric cancer (EGC) is a minimally invasive and curative treatment. The value of endoscopic ultrasonography (EUS) in determining the therapeutic strategy for EGC was assessed in this study.Materials and Methods. Pretreatment EUS was performed on 406 EGCs. The lesions were divided into the histological categories m/sm1 and sm2. The EUS-determined depths of invasion were classified as EUS-M/SM1, EUS-SM2, and EUS-MP or deeper. An analysis of the factors influencing the EUS-based depth determination was then conducted.Results. Most (92.8%) of the EUS-M/SM1 group belonged to the m/sm1 histological category. Ulcerated lesions, tumor size of larger than 2 cm, and the use of an ultrasound endoscope were independently associated with misdiagnosis of the depth of EGC by EUS. The ulcerated lesions had a significantly higher probability of overestimation.Conclusions. EUS is a useful method for determining the therapeutic strategy for EGC. Special attention should be paid not to overestimate the depth of cancer invasion when determining the ulcerated lesions and the type of curative procedure to be used.

Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (EUS-FNA) play increasingly prominent roles in the diagnosis and management of pancreatic cysts. The Asian Consortium of Endoscopic Ultrasound was recently formed to conduct collaborative research in this area. This is a review of literature on true pancreatic cysts. Due to the lack of systematic studies, there are no robust data on the true incidence of pancreatic cystic lesions in Asia and any change in over the recent decades. Certain EUS morphological features have been used to predict particular types of pancreatic cysts. Pancreatic cyst fluid viscosity, cytology, pancreatic enzymes, and tumor markers, in particular carcinoembryonic antigen, can aid in the diagnosis of pancreatic cysts. Hemorrhage and infection are the most common complications of EUS-FNA of pancreatic cysts. Pancreatic cysts can either be observed or resected depending on the benign or malignant nature, or malignant potential of the lesions. Guidelines from an international consensus did not require positive cytological findings to be present in their recommendation for resection, which included all mucinous cystic neoplasms, all main-duct intraductal papillary mucinous neoplasms (IPMN), all mixed IPMN, symptomatic side-branch IPMN, and side-branch IPMN larger than 3 cm. In patients with poor surgical risks, EUS-guided cyst ablation of mucinous pancreatic cysts is an alternative. As long-term prospective data on pancreatic cysts are still not available in Asia, management strategies are largely based on risk stratification by surgical risk and malignant potential. Gene expression profiling of pancreatic cyst fluid and confocal laser endomicroscopic examination of pancreatic cysts are novel techniques currently being studied.

High-pressure phase equilibrium relations of the 1,1-difluoroethane (HFC-152a) + water binary system were investigated in a temperature range of (275.03 to 319.30) K and a pressure range up to 370 MPa. Four three-phase coexisting curves of hydrate + aqueous + gas phases, hydrate + HFC-152a-rich liquid + gas phases, hydrate + aqueous + HFC-152a-rich liquid phases, and aqueous + HFC-152a-rich liquid + gas phases originate from the quadruple point of hydrate + aqueous + HFC-152a-rich liquid HFC-152a + gas phases located at (288.05 ± 0.15) K and (0.44 ± 0.01) MPa. The structure of HFC-152a hydrate remains structure I (s-I) in the pressure range up to 370 MPa. Raman spectra of the HFC-152a molecule in the HFC-152a hydrate indicate that the HFC-152a molecules occupy only large cages of s-I HFC-152a hydrate in the presence of completely vacant small cages at a pressure up to 370 MPa.

Aim: Peppermint oil solution was found to be effective for reducing gastric spasm during upper gastrointestinal endoscopy. The aim of the present study was to assess whether the gastric peristalsis-suppressing effect is dose-dependently induced by L-menthol, the major constituent of peppermint oil, and to determine the recommended dose of an L-menthol preparation. Methods: In this phase II, multicenter, double-blind, dose–response study, 131 eligible patients were randomly assigned to receive 20 mL of 0.4% L-menthol (n = 32), 0.8% L-menthol (n = 35), 1.6% L-menthol (n = 30), or placebo (n = 34). The primary efficacy measure was the proportion of subjects with no peristalsis in two time periods, 75 to 105 s after treatment and immediately before the completion of endoscopy. Results: The peristalsis-suppressing effect of L-menthol increased dose dependently (5.6%, 32.0%, 47.4% and 52.9% in the 0%, 0.4%, 0.8% and 1.6% groups, respectively: P

GI peristalsis during GI endoscopy commonly requires intravenous or intramuscular injection of antispasmodic agents, which sometimes cause unexpected adverse reactions.Our ultimate goal was to evaluate whether the antiperistaltic effect of L-menthol-based preparations facilitates endoscopic examinations in a clinical setting.Multicenter, randomized, double-blind, placebo-controlled study.Six Japanese referral centers.A total of 87 patients scheduled to undergo upper GI endoscopy were randomly assigned to receive 160 mg of L-menthol (n=45) or placebo (n=42). Both treatments were sprayed endoscopically on the gastric mucosa. The degree of gastric peristalsis was assessed by an independent committee.The proportion of subjects with no peristalsis 90 to 135 seconds after administration and at the end of the endoscopic examination (complete suppression of gastric peristalsis). Other outcomes were the proportion of subjects with no or mild peristalsis (adequate suppression of gastric peristalsis) and the ease of intragastric observation as evaluated by the endoscopist who performed the procedure.Gastric peristalsis was completely suppressed in 35.6% (21.9, 51.2) of the L-menthol group compared with only 7.1% (1.5, 19.5) of the placebo group (P.001). In the L-menthol group, 77.8% (62.9, 88.8) (35/45 subjects) of the subjects had no or mild peristalsis at the completion of endoscopy. Minor peristalsis interfered with intragastric examination in only 1 of these 35 patients (2.9%). The incidence of adverse events did not differ significantly between the groups (P=.512).Small sample size.During upper GI endoscopy, L-menthol sprayed on the gastric mucosa significantly suppresses peristalsis with minimal adverse drug reactions compared with placebo. (NCT00742599.).

Background & Aims We evaluated the diagnostic ability of a newly developed peroral video cholangioscopy (PVCS) in patients with pancreaticobiliary disorders. Methods We retrospectively evaluated data from 144 patients with pancreaticobiliary disorders, collected from 5 tertiary referral centers. Endoscopic sphincterotomy (EST) or endoscopic papillary balloon dilation (EPBD) was performed before PVCS. We performed 2 types of PVCS, using a conventional therapeutic duodenoscope. If tissue samples were needed, cholangioscopy-assisted biopsy or fluoroscopy-guided biopsy was performed. Results PVCS was advanced into the bile duct in all cases after patients received EST (n = 134 cases), EPBD (n = 2), a combination of EST and EPBD (n = 1), or without treatment of the major papilla (n = 7). Biopsy samples were collected successfully from 112 of 120 cases in which endoscopists considered tissue sampling necessary. Endoscopic retrograde cholangiopancreatography (ERCP)/biopsy correctly identified 83 of 96 malignant lesions and 19 of 24 benign lesions (accuracy = 85.0%; sensitivity=86.5%; specificity=79.2%; positive predictive value=94.3%; negative predictive value=59.4%). Endoscopic retrograde cholangiopancreatography (ERCP)/biopsy plus PVCS correctly identified 95 of 96 malignant lesions and 23 of 24 benign lesions (accuracy = 98.3%; sensitivity=99.0%; specificity=95.8%; positive predictive value=99.0%; negative predictive value=95.8%). Procedure-related complications included pancreatitis (4 cases, 2.8%) and cholangitis (6 cases, 4.3%). Conclusions PVCS is an accurate diagnostic tool for patients with pancreaticobiliary disorders; resolution was well-defined when combined with biopsy analysis. Prospective multicenter clinical trials should evaluate the clinical utility of PVCS in diagnosis of biliary tract diseases.

A case of basket catheter impaction was experienced during treatment for a common bile duct (CBD) stone. In cases of large CBD stones, mechanical basket lithotripsy or extracorporeal shock wave lithotripsy (ESWL) is usually carried out. However, once basket catheter impaction occurs, ESWL should be performed in the remaining basket catheter, which is passed through the patient's nose, and further ESWL basket lithotripsy must be carried out at a later time. On one occasion, a mechanical lithotripter was inserted along-side the conventional basket catheter through the incised papilla. This procedure is a safe and useful method for the clearance of CBD stones that cannot be removed with standard endoscopic procedures due to an impacted basket catheter.

Endoscopic hemostasis is widely performed for nonvariceal upper gastrointestinal (UGI) bleeding. As the aged Japanese population rapidly increases, the number of patients experiencing complications increases. The aim of this study was to evaluate the recent results of endoscopic hemostasis for nonvariceal UGI bleeding. A retrospective analysis of patients who underwent endoscopic procedures for nonvariceal UGI bleeding was performed. We performed 223 endoscopic procedures on 217 patients between January 1995 and July 2000, and 238 endoscopic procedures on 236 patients between January 2006 and September 2009 at the Kyoto Second Red Cross Hospital. We divided the patients into the 1995–2000 group and the 2006–2009 group. Patient characteristics, hemostasis methods chosen, rates of temporary hemostasis and rebleeding, and mortality were analyzed. There were many serious and actively bleeding cases in the 2006–2009 group (P

Background and Objectives: EUS-guided biliary drainage (EUS-BD) was shown to be useful for malignant biliary obstruction (MBO). However, there is lack of consensus on how EUS-BD should be performed. Methods: This was a worldwide multi-institutional survey among members of the International Society of EUS conducted in February 2018. The survey consisted of 10 questions related to the practice of EUS-BD. Results: Forty-six endoscopists of them completed the survey. The majority of endoscopists felt that EUS-BD could replace percutaneous transhepatic biliary drainage after failure of ERCP. Among all EUS-BD methods, the rendezvous stenting technique should be the First choice. Self-expandable metal stents (SEMSs) were recommended by most endoscopists. For EUS-guided hepaticogastrostomy (HGS), superiority of partially-covered SEMS over fully-covered SEMS was not in agreement. 6-Fr cystotomes were recommended for fistula creation. During the HGS approach, longer SEMS (8 or 10 cm) was recommended. During the choledochoduodenostomy approach, 6-cm SEMS was recommended. During the intrahepatic (IH) approach, the IH segment 3 was recommended. Conclusion: This is the first worldwide survey on the practice of EUS-BD for MBO. There were wide variations in practice, and randomized studies are urgently needed to establish the best approach for the management of this condition.

Background Double-balloon enteroscopy (DBE) is a useful and epoch-making technique for small-bowel diseases. The single-balloon enteroscope (SBE) is a new instrument introduced by Olympus. Objective To evaluate a prototype of the SBE. Design A prospective case series. Setting Kyoto Second Red Cross Hospital, between April 2006 and July 2007. Patients We used the SBE system to perform 37 enteroscopic examinations on 27 patients, including 22 oral and 15 anal approaches. Main Outcome Measurements The rate of whole small-bowel visualization, mean time necessary for the investigation, discovery rate of lesions, and complications. Results We observed the entire small intestine in 1 of 8 cases (12.5%) that we examined. The mean (±SD) time necessary for the oral approach was 83 ± 38 minutes and that for the anal approach was 90 ± 32 minutes. The preparation time was less than 5 minutes in both approaches. Small-intestinal lesions were detected in 11 of the 27 patients (40.7%). Perforation occurred in one case as a complication, but the injury healed without surgical intervention. Limitation This was a single-center study. Conclusions Use of the SBE system in the endoscopic study of the small intestine makes it possible to observe the entire small intestine and to diagnose lesions; thus, the SBE system is a useful instrument for small-bowel diseases. However, the rate of whole small-bowel visualization was inferior to the DBE system.

Used with narrow band imaging (NBI), peroral cholangiopancreatoscopy (PCPS) was performed in eight patients with biliary and pancreatic diseases. The procedures were successfully performed in all patients without any complications after endoscopic sphincterotomy. Direct endoscopic diagnosis within both the bile and pancreatic ducts was well accomplished by the baby scope with NBI. NBI produced higher quality images and was able to show changes of the bile duct wall due to tumor growth. However, bile is seen as red on NBI, so sufficient cleaning of the bile duct is recommended. It is concluded that this procedures is considerably valuable and enables PCPS to easily detect biliary lesions.

A gastric wall abscess is rare and it can reportedly appear similar to a submucosal tumor on endoscopy. Few reports have described endoscopic ultrasonographic findings for a gastric wall abscess. An 84-year-old man was admitted to our hospital for tarry stools. Esophagogastroduodenoscopy showed an elevated lesion similar to a submucosal tumor at the posterior wall of the stomach. Erosion and a white coat were observed on top of the lesion. Endoscopic ultrasonography showed an anechoic lesion connected to the proper muscular layer with a hyperechoic area in the center of the lesion. The lesion was diagnosed as a gastric wall abscess using endoscopic ultrasound-guided fine-needle aspiration and was treated with endoscopic ultrasound-guided drainage. The final diagnosis was a gastric wall abscess presenting as gastrointestinal hemorrhage. The patient was discharged with internal drainage stents. Computed tomography performed 3 months after discharge did not show recurrence of the abscess.

The detection of early gastric cancer is performed by endoscopic study with or without the dye-spraying method, which is useful in detecting small lesions or surface lesions. For the diagnosis of early gastric malignancy, magnification endoscopy, narrow-band imaging and optical coherence tomography are used for histological diagnosis and research. On the other hand, endoscopic ultrasonography is used to discuss the depth of carcinoma invasion, but cannot be used to detect the malignant lesions except for the rare cases of scirrhus-type gastric carcinoma, the histological results of which are sometimes difficult to obtain by biopsy study. The role of endoscopic ultrasonography diagnosis is to assist in making a decision of therapeutic strategy. Curative endoscopic treatment of early gastric cancer is common according to the development of various endoscopic techniques and accessories. Curative treatment is feasible using these techniques.

Background: Endoscopic ultrasonography (EUS) is widely accepted as a diagnostic tool for bilio-pancreatic and gastrointestinal tract diseases. Recently, an ultrasound endoscope with an electronic radial scan transducer has been developed. To evaluate the clinical usefulness of this system, its image quality, advantages and disadvantages were evaluated. Materials and methods: Ultrasound endoscope with electronic radial scan transducer and its monitor unit were used. The direction of the imaging plane was similar to that of the mechanical radial models. Color Doppler function and tissue harmonic imaging were feasible by this system. To evaluate this endoscope, we investigated the image quality and distance resolution by in-vitro study using thin papers, and 50 patients were examined by this system. Results: Comparison with the mechanical radial endoscope GF-UM2000 revealed that the image quality was almost equivalent. However, the ultrasound penetration of the electronic radial scanner was better and more satisfactory with less echoic reduction. In addition, the blood-flow signal could be obtained by using the color Doppler function. In contrast, the diameter of the new endoscope was bigger than the advanced mechanical radial models, the monitor unit was bigger than that of the mechanical radial system, and the operation of this unit was complicated. Conclusion: A prototype of the ultrasound endoscope with electronic radial scan showed satisfactory results regarding the image quality, ultrasound penetration, and clinical diagnosis. The blood flow could be investigated by using the color Doppler function, which is useful to diagnose lesions and detect involvement of the blood vessels in cancers.

Background: Occlusion due to tumor ingrowth is a major drawback in self-expandable metallic stents. Covering the stent is a probable solution to prevent tumor ingrowth. A manufactured covered self-expandable metallic stent, Covered Wallstent, has become commercially available. We evaluated the Covered Wallstent in a prospective uncontrolled multicenter setting. Methods: Between October 2001 and October 2003, 97 patients with common bile duct strictures deemed unfit for surgical resection underwent placement of a single Covered Wallstent, and were followed prospectively until April 2004. Results: Placement of the stent was successful in all the patients attempted. As a procedure-related complication, acute pancreatitis developed in four patients, in one of whom obstruction of the pancreatic duct orifice with the stent body seemed to be a major cause. The 30-day mortality was 9.3% (nine patients). Stent occlusion occurred in 22 patients as a late (greater than 30 days) complication, due to either tumor overgrowth (14 patients) or encrustation (eight patients). Distal migration of the stent was demonstrated in two other patients. No stent occlusions due to tumor ingrowth were observed. Patency rates of the stent for 3-, 6-, and 12-month periods were, respectively, 90.7, 82.5, and 45.9%. Conclusions: The present results in a large series suggest that placement of the Covered Wallstent is feasible and effective in the palliation of patients with malignant common bile duct strictures. The Covered Wallstent seems to be reliable in eliminating tumor ingrowth. The role of stent covering in promoting stent function should be examined in a prospective comparative study between covered- and uncovered Wallstents.

The diagnosis of intraductal papillary mucinous tumor (IPMT) can be performed under the direct visualization of peroral pancreatoscopy (PPS), although the visible field with PPS is limited and endoscopic accessories cannot be easily applied. PPS is useful in cases with IPMT not only for the main duct lesions but also for some of the branch lesions that can be shown through the dilated branch duct. PPS is useful for diagnosing IPMT because histologic diagnosis is possible from biopsy materials obtained by PPS or with radiograph guidance. Histologic findings can be suspected from the appearance and degree of the protrusion of the lesions in the cystic lesion or in the main duct. Thirty patients with IPMT were resected and confirmed histologically. Among them, 26 cases were examined by PPS. Detection rates of the 12 cases with polypoid tumor greater than 3 mm were 67% by PPS, 92% by endoscopic ultrasonography, and 100% by intraductal ultrasonography. Among the 6 cases of adenocarcinoma, 4 cases showed a tumor mass greater than 10 mm.

A prototype electronic radial scan ultrasound endoscope has been developed by Olympus (Tokyo, Japan) for endoscopic ultrasound (EUS) study. The ultrasound view-angle of this model is 360° vertical to the scope. Though the diameter of the scanner and the shaft of the scope is bigger than those of the present mechanical radial scan model, clinical manipulation of the new scope is the same as that of the present model. Image quality of the ultrasound picture demonstrated by the electronic radial model was as clear as those provided by the mechanical radial scan model. Ultrasound penetration was better and satisfactory because of less echoic reduction compared to the mechanical radial model. The newly developed electronic radial model can be evaluated as an ultrasound endoscope for the next generation. The advantage of this system is to facilitate the clinical use of color Doppler function and tissue harmonic imaging, and this system can be operated by the same monitor unit as a convex model of ultrasound endoscope.

Standard imaging techniques using a radical scanning echoendoscope are summarized to facilitate the attainment of expertise in biliopancreatic endoscopic ultrasonography and to promote the widespread use of this diagnostic tool. Typical images of the biliopancreatic system and neighboring organs obtained by scanning from the stomach, duodenal bulb, and descending portion of the duodenum are shown in a sequential manner. Two methods of scanning from the descending portion of the duodenum, which is considered to be the most difficult, are presented (i.e. the Longitudinal Method and the Transverse Method). In addition, settings of the image control functions and the monitor are also detailed.

Background: Intraductal papillary-mucinous tumor (IPMT) of the pancreas has a broad spectrum of histology ranging from hyperplasia to adenocarcinoma. Therefore, it is important to differentiate between the malignant and benign lesions to determine the therapeutic strategy for IPMT. Patients and Methods: Thirty-nine patients with IPMT (27 men and 12 women, mean age: 63.3 years) underwent surgery between January 1985 and March 2002. The size of the cystic lesion, the maximum diameter of the main pancreatic duct (MPD), and the height of the papillary tumor inside the cyst were investigated by endoscopic ultrasonography (EUS) and/or intraductal ultrasonography (IDUS) before operation. These preoperative clinical findings were compared with the pathological findings of the resected specimen. Results: The size of the cystic lesion, the diameter of MPD, and the height of the papillary tumor in cases with malignant IPMT (invasive and non-invasive carcinoma) were larger than those in cases with benign IPMT (adenoma and hyperplasia). Analysis of the images of the lesions revealed that the following three factors are important for diagnosing IPMT: (i) the size of the cystic lesion is ≥ 30 mm; (ii) the diameter of MPD is ≥ 8 mm; (iii) the height of the papillary tumor inside the cyst is ≥ 3 mm. It was not significant to differentiate between benign and malignant IPMT based on factor (i), but statistically significant (P

Early gastric carcinoma is mainly detected and diagnosed by endoscopic examination with or without biopsy. In general, the diagnosis of early gastric carcinoma is easily accomplished by endoscopic observation and pathologic evaluation of endoscopic biopsy. Endoscopic detection of gastric carcinoma depends on the recognition of visible mucosal changes. However, the final diagnosis is achieved by histopathologic study of biopsy material. Biopsy is very important in obtaining the correct diagnosis of carcinoma, adenoma, hyperplasia, and metaplasia, although it is often possible to distinguish these lesions by the endoscopic characterization of mucosal surface details. Endoscopy has been improved from fiberoptic to video-imaging systems that use charged-coupled devices (CCDs). In addition, cross-sectional images can be obtained by using EUS.1-3 The development of magnification endoscopy can show the precise surface pattern. Furthermore, the recent development of endoscopic optical coherence tomography (EOCT) provides a future promise of histologic diagnosis in vivo.

The single-balloon enteroscopy (SBE) system was launched in 2007, proposed as a simpler method than double-balloon enteroscopy (DBE). Controversy surrounds whether the SBE system has the same insertability as DBE. However, many methods have been proposed to improve the depth of insertion with the SBE system, involving several techniques and endoscopic accessories. SBE is used for investigating not only small bowel diseases, but also diseases of the pancreatobiliary and colonic structures. SBE is a necessary advancement for many endoscopic procedures and applications in modern clinical practice. In our review, we summarized the current literature concerning the insertability of SBE and described the technical aspects of improving the rate of deep insertion in SBE procedures. In addition, the recent applications of SBE to diseases besides those of the small bowel are described.

A limited number of endoscopic retrograde cholangiopancreatography (ERCP) accessories are compatible with the conventional single-balloon enteroscope (SBE) because of the latter's dimensions. The aim of the present study was to assess the utility of a prototype SBE that has a shorter working length and a wider channel than the conventional SBE.ERCP procedures carried out between January 2012 and July 2013 using the short SBE prototype were reconstructions such as Billroth II (B-II), post-gastrectomy with Roux-en-Y (RY-G), and post-choledochojejunostomy with Roux-en-Y (RY-CJ). We retrospectively analyzed the rate of reaching the blind end of the intestine, the diagnostic success rate, the interventional success rate, and the frequency of related complications.Twenty-seven ERCP procedures on 18 patients analyzed comprised two B-II, 15 RY-G, and 10 RY-CJ reconstructions. With a mean procedure time of 56 min (range 40-150 min), the rate of reaching the blind end, the diagnostic success rate, and the interventional success rate were 24/27 (89%), 20/27 (74%), and 19/27 (70%), respectively. There were no major ERCP-related complications in any patient.The prototype short-type SBE appears safe and effective for use in ERCP, and is compatible with conventional endoscopy accessories.

Background: A new plastic stent was designed for endoscopic biliary stenting to achieve a long and effective drainage period. Method: The Double layer stent is composed of Teflon as the inner layer and nylon as the outer layer divided with metallic mesh. This structure gives the stent several side-flaps without side-holes. Double layer stents were applied in 24 patients with inoperable malignant biliary obstruction. Results: The Double layer stents were successfully placed in all cases, and the effective drainage rate of these stents was 96%. The mean patency period evaluated by the Kaplan–Meier method without ineffective cases was 207 days, which was longer than the ordinary plastic stent of the same diameter. Concerning the complications related to inserting, we experienced dislocation was experienced in three patients. Conclusions: The authors regard this new device as an useful stent, which users can expect long patency period, easy exchange management, and reduced cost for the patients with inoperable obstruction in the biliary tract.

Background: It has been reported that cathepsin E (CTSE) is a non-secretory and intracellular aspartic proteinase found in the superficial epithelial cells of the stomach and that it is also expressed in pancreatic ductal adenocarcinoma. We evaluated the diagnostic value of CTSE in the pancreatic juice in the diagnosis of pancreatic ductal adenocarcinoma compared with that of CA19–9, carcinoembryonic antigen (CEA) and K-ras mutations. Methods: One hundred and one patients (25 with pancreatic ductal adenocarcinoma and 76 with chronic pancreatitis) were examined for the diagnostic significance of CTSE in the pancreatic juice in the diagnosis of pancreatic ductal adenocarcinoma. Forty of 101 patients (15 with pancreatic ductal adenocarcinoma and 25 with chronic pancreatitis) were examined to compare the diagnostic value of various tumor markers in the pancreatic juice, namely CA19–9, CEA, K-ras mutations and CTSE. Results: The detection frequency of CTSE was significantly higher in patients with pancreatic ductal adenocarcinoma (64.0%) than in patients with chronic pancreatitis (7.9%; χ2 = 34.76; P < 0.0001). The sensitivity, specificity and diagnostic accuracy of CTSE in the pancreatic juice for pancreatic ductal adenocarcinoma was 66.7, 92.0 and 82.5%, respectively. These values were more efficient in comparison with those of CA19–9, CEA and K-ras mutations. The main cause of the detection failure of CTSE in pancreatic ductal adenocarcinoma was obstruction of the main pancreatic duct. Sensitivity was 85.7% in patients without obstruction of the main pancreatic duct. Conclusions: Cathepsin E in the pancreatic juice is a novel marker for a definitive diagnosis of pancreatic ductal adenocarcinoma.

Background: Intraductal ultrasonography of the bile/pancreatic duct using a thin-caliber ultrasonic probe (IDUS) provides excellent images of these ducts and the surrounding structures. Insertion of the device through the papilla of Vater is essential to carry out this examination. We developed a new probe with a ropeway system (XUM5RG-29R; Olympus, Tokyo) for transpapillary IDUS. Its usefulness such as ease of application and safety were prospectively evaluated. Patients and methods: During the period of October 1997 to April 1998, transpapillary IDUS using the probe was performed in 194 patients at seven medical institutions. The success rates of insertion of the probe into the bile/pancreatic duct, observation of the area of interest, and the incidence of complications were evaluated. Results: Passage of the probe through the papilla was successful without difficulty in all the patients. Successful introduction of the probe into the pancreatic duct, bile duct and both of the ducts was achieved in 98.4, 100 and 85% of the patients, respectively. Once the probe was introduced into the aimed duct, it was possible to obtain IDUS images of the area of interest in all but five patients. Mild acute pancreatitis developed in eight patients (4.1%), all of whom recovered with conservative therapy only. Conclusions: It is possible to introduce the new ultrasonic probe into the desired duct once a guide wire has been inserted. This type of ultrasonic probe is quite useful when performing transpapillary IDUS of the bile and/or pancreatic duct.

患者は68歳女性で, 右季肋下で5横指, 心窩部で4横指にわたる肝腫大を認めた. 血液検査成績では, 血清アルブミンの著しい低下と胆道系酵素の上昇を認めた. 腹部造影CT検査にて肝右葉と左葉の一部に造影効果の乏しい部分を認め, dynamic MRIでも同様の部位に著しい造影効果の低下を示した. また, 99mTc-PYP (ピロ燐酸) シンチグラムにて肝に取込みを認め, 肝アミロイドーシスを疑った. 超音波下肝生検像では, アミロイドの沈着および肝細胞の圧迫と萎縮を認めた. 免疫組織学的検討では, 沈着物質はκ型AL蛋白であり, 原発性アミロイドーシスと診断し, 腎生検でも同様の所見が得られた. アミロイドーシスの確定診断は組織学的手段によるが, 近年の画像診断の進歩はめざましく, 各種の画像診断法を駆使することで肝生検に迫る診断が可能であると考える.

The height of the mural nodules and papillary tumors in main pancreatic duct or dilated branch duct is the most important factor for diagnosis of intraductal papillary mucinous neoplasm (IPMN). In this study, the authors compared the height of the papillary lesions and mural nodules between the height of resected tissues and the height detected by the preoperative imaging tools (endoscopic ultrasonography [EUS] and intraductal ultrasonography [IDUS]) in 38 patients with IPMN. In 21 out of 23 cases of adenoma, and in cases with the non-invasive cancer, the difference of the height of operative and preoperative analysis measured by EUS and IDUS was within 1–2 mm. EUS and IDUS are useful for diagnosis of degree of malignancy in IPMN.

We prepared a monoclonal antibody (mAb), IgM class, to rabbit muscle aldolase (ALD) A4. The mAb reacted with the ALD A subunit but not with the B and C subunits. Distribution of the ALD A subunit was studied employing immunohistochemistry, with the ABC procedure in the rabbit tissues. The ALD A subunit was localized in the l-band of the skeletal muscle fibers. In the liver, endothelial cells showed strong immunoreactivity while parenchymal cells were negative or yielded only a faint reaction. The collecting tubules were positively stained in the kidney. Strong reactivity was seen in the proximal tubules of the outer medulla but not in those of the cortex. In the adrenal gland, cells in the cortex exhibited strong immunostaining, while medullary cells were negative. In the testis, most of the seminiferous epithelium was moderately immunoreactive. Intense staining was present in interstitial cells. The ALD A subunit was localized in the interstitial cells and follicular cells of primary follicles in the ovary. In the cerebellum, the ALD A subunit was localized exclusively in nerve fibers of the white matter; Purkinje cells and nerve cells in the granular layer were negative.

Background and study aims: Despite the development of peroral video cholangioscopy (PVCS), no prospective multicenter studies have been undertaken to investigate the diagnostic accuracy of PVCS in biliary tract diseases. Therefore, the aim of this study was to clarify the accuracy of PVCS in evaluating biliary tract lesions. Patients and methods: This study was a prospective multicenter study at five tertiary referral centers in Japan and included 87 eligible patients with biliary tract diseases who underwent PVCS. The study evaluated the ability of PVCS to diagnose indeterminate biliary tract diseases, detect mucosal cancerous extension preoperatively in extrahepatic bile duct cancers, and predict adverse events. Results: The use of PVCS appearance alone correctly distinguished benign from malignant indeterminate biliary lesions in 92.1 % of patients whereas biopsy alone was accurate in 85.7 %. In extrahepatic bile duct cancer, mucosal cancer extended histologically at least 20 mm in 34.7 % (17/49) of patients. The accuracy rate of PVCS to evaluate the presence or absence of mucosal cancerous extension by endoscopic retrograde cholangiography (ERC) alone, ERC with PVCS, and ERC with PVCS + biopsy were 73.5 %, 83.7 %, and 92.9 %, respectively. Adverse events were seen in 6.9 % of PVCS patients, but no serious complications were observed. Conclusion: PVCS enhanced the accurate diagnosis of biliary tract lesions by providing excellent resolution in combination with biopsy.

In Asia, the incidence of pancreatic cancer in some countries has been increasing. Owing to most cases being diagnosed late, prognosis for pancreatic cancer remains dismal. It is clear that the future for pancreatic cancer lies in early detection. While the possible presence of pancreatic masses is often first raised by non-invasive abdominal imaging, such as computerized tomography and magnetic resonance imaging, smaller lesions and locoregional lymph node metastases are often not detectable by these means. Endoscopic ultrasonography (EUS) offers a higher sensitivity (93-100%) for detection of small potentially curable pancreatic masses than other existing imaging modalities. It is also recommended for the evaluation of portal vein confluence, portal vein, celiac axis, and superior mesentric artery origin, and exclusion of resectability. Due to the closer proximity of EUS to the target structure, and lower rate of needle tract seeding, EUS-guided fine-needle aspiration of pancreatic mass is considered the most suitable tissue acquisition technique. Lastly, EUS also enables the performance of endoscopic interventions. Its performance can be further enhanced with newer techniques, including contrast-enhanced ultrasound and elastrography. It is anticipated that in the near future, molecular technologies may make it possible to detect microscopic amounts of cancer in tissue or blood, predict relapse and survival after therapy, as well as determine optimal therapy.

Branch-duct intraductal papillary mucinous neoplasm (BD-IPMN) is recognized as a risk factor for pancreatic ductal adenocarcinoma (PDAC) that is unrelated to the malignant transformation of IPMN. We experienced 8 cases of resected PDAC concomitant with IPMN from March 1988 to December 2012, and 7 patients had2 risk factors, including IPMN, for pancreatic cancer. Seven of the IPMNs were30 mm in size, while none had mural nodules. Four cases of PDAC were detected during the follow-up period for BD-IPMN. Neither magnetic resonance cholangiopancreaticography nor contrast-enhanced computed tomography performed 5 months prior to the detection of PDAC resulted in its early detection in 2 cases. The clinical features of the 8 cases indicate that particular attention is required for patients with1 risk factor, in addition to IPMN, for pancreatic cancer. A shorter interval of surveillance than that suggested by the international consensus guidelines 2012 is required, even if the IPMNs are small, for the early detection of PDAC.

The ultrasonograms of ulcerative colitis (UC) in active stage show hypoechoic changes of the colorectal wall from the mucosal layer to the deeper layers. These endoscopic ultrasound (EUS) changes of the wall recognized in active stage disappear or normalize in the stage of remission. When the stage of UC is exacerbated, the hypoechoic changes of the wall extend from the mucosal layer to the deeper layers with the increase of wall thickness. These EUS images of active UC are classified into the following types: UC-M, thickening of the whole wall with the structure preserved; UC-SM, hypoechoic changes reach the superficial portion of third layer with the thickening of whole wall; UC-SM deep, hypoechoic changes reach the deeper portion of third layer with the thickening of whole wall; UC-MP, hypoechoic changes reach the fourth layer with the thickening of whole wall; UC-SS/SE, hypoechoic changes penetrate through the fourth layer with the thickening of whole wall. With the help of EUS we can demonstrate the severity of inflammation in UC. Moreover, in severe cases of UC, the treatment strategy including emergency surgery can be determined. EUS is a valuable method in the management of UC.

Recently, an indication of gastrointestinal stenting is not only esophageal stenosis but it extends from the esophagus to the gastric outlet and duodenum. However, there are some problems such as shortness of the device for esophageal stenting, angulations of stenotic sites, and so on, when we perform the stenting for stenoses of the gastric outlet and duodenum. Until now, some refinements of stent insertion technique have been attempted to solve these problems. In this paper, we report three cases in which self-expanding metallic stents were placed for stenoses of the gastric outlet and duodenum with refinements of stent insertion technique. Our attempts in these patients were an extension of stenting device to insert stents easily, and placement of covered metallic stent inside non-covered metallic stent or a fixation of covered metallic stent to the gastrointestinal wall by means of endoclips to avoid dislocation of stents. Stents were inserted successfully in all patients, and the nutrition of these patients was improved after the placement of stents. Further refinements of stents and stent insertion technique are expected to achieve easy manipulation.

We have experienced a case with perforation after endoscopic balloon dilatation. The patient was diagnosed as having malignant lymphoma in the terminal ileum, and treated with eradication of H. Pylori and chemotherapy. The severe stenosis appeared at the same site of the tumor after the medical treatment. The first dilatation with a 15 mm balloon was successful. The lower small bowel obstruction occurred 14 months after the first balloon dilatation. The second dilatation with an 18 mm balloon was performed. The stricture site was remarkably dilated and could be passed by the scope. Perforation was confirmed because of the complaint of severe abdominal pain. The laparotomy finding showed the hole at the stricture site and remarkable fibrosis without tumorous tissue. The fragility of the tissue, the excessive inflation of the balloon and the insertion of the scope might be causes of the perforation. The case with severe stricture having almost no flexibility should be considered carefully in the determination of treatment procedures for the balloon dilatation.

We applied a newly developed endoscopic resection technique for a rectal mucosal cancer of 4.2 cm. This method resulted in a curable treatment and provided precise information for histological examinations. This technique, using IT-knife, may involve the risk of bleeding and perforation compared with conventional methods. Further improvements are needed to make this technique safer and more reliable for a standard endoscopic method for large colorectal tumors.

The purpose of this study was to determine (1) the diagnostic yield for endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with pancreatic cystic lesions, (2) additional value of EUS-FNA over EUS alone in the diagnosis of pancreatic cysts, and (3) diagnostic sensitivity and specificity of EUS and EUS-FNA in the subset of patients where histopathology of surgical specimens were available.All patients who underwent EUS examination for the evaluation of pancreatic cystic lesions in six Asian centres were included in the study.Of 298 patients with pancreatic cysts who underwent EUS, 132 (44.3 %) underwent FNA. In the entire cohort, pseudocysts and intraductal papillary mucinous neoplasm (IPMN) were the predominant cystic lesions. The cytologic yield of EUS-FNA was 47 %. On univariate analysis, factors associated with higher cytologic yield included vascular involvement on EUS, presence of solid cystic component, and increased number of needle passes during EUS-FNA. On multivariate analysis, presence of solid cystic components and increased number of needle passes during EUS-FNA were associated with higher diagnostic yield of EUS-FNA. For pancreatic cysts with a solid component, the diagnostic yield of EUS-FNA increased significantly from 44 % with one pass to 78 % with more than one pass (p = 0.016). In the absence of a solid component, the diagnostic yield was 29 % with one pass and was not significantly different from the diagnostic yield of 50 % with more than one pass, p = 0.081.The cytologic yield of EUS-FNA was 47 %. When a solid component was present in the cyst, doing more than one pass during EUS-FNA increased its diagnostic yield.