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Kenjiro Yasuda

Publications and source records attributed to Kenjiro Yasuda.

7 recordsLinked to original sources
PubMed2006

Early gastric cancer: diagnosis, treatment techniques and outcomes.

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.

Early Diagnosis↗
PubMed2005

Role of endoscopic ultrasonography in the diagnosis of early esophageal carcinoma.

Endoscopic ultrasonography (EUS) for the diagnosis and staging of early esophageal carcinoma is discussed. Based on the nine-layered structure of esophageal wall, which is in good correspondence with histological layers, depth of carcinoma invasion can be investigated. Ultrasound endoscopes and probes are used for the examination. Ultrasound probes with 20 MHz and 30 MHz transducers can demonstrate the clear images of early esophageal carcinoma by using water filling method, which can discuss the change of the esophageal wall from the surface layer. Although the early esophageal carcinoma is detected by endoscopic findings with or without the dye spraying method by iodine, the diagnosis of depth of carcinoma invasion is not easy. EUS can assist in the diagnosis of depth of carcinoma invasion. Confirming the depth of carcinoma invasion by EUS and the lesion is limited to the mucosa. Endoscopists can decide the indication for endoscopic resection of the lesions.

Adenocarcinoma↗
PubMed2005

The use of pancreatoscopy in the diagnosis of intraductal papillary mucinous tumor lesions of the pancreas.

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.

Cystadenoma, Papillary↗
PubMed2003

Endoscopic ultrasonography for upper gastrointestinal submucosal lesions: a cost minimization analysis with an international perspective.

OBJECTIVES: Our prospective clinical study of prospectively compared physicians' management of submucosal tumors (SMTs) with and without endoscopic ultrasound (EUS). It showed that EUS reduced further tests by more than 50%, but it is unclear whether it reduced the overall costs. The aim of this study was to determine whether EUS would reduce costs. METHODS: Based on the data from the clinical study, a decision analysis was created to compare the direct hospital costs for diagnosing SMTs with and without EUS. Cost data from Germany, Canada, Japan, France, and the United States were used. Costs were expressed as a ratio of the cost of esophagogastroduodenoscopy (EGD). Average cost ratios for each procedure were as follows (sensitivity analysis ranges are 95% CIs): EGD = 1; large particle biopsy (LPB) 0.75 (0.22-1.24); endoscopic ultrasound (EUS) 2.0 (1.22-2.79); abdominal ultrasound (US) 0.77 (0.31-1.24); computed tomography (CT) 1.79 (0.64-2.95); magnetic resonance imaging (MRI) 3.54 (1.28-5.79); and ERCP 3.45 (0.82-6.07). RESULTS: Initial inputs show the "no EUS" strategy is less costly when cost data for all countries are averaged (expected cost 2.13 vs 2.71, expressed as a ratio of the cost of EGD]) and for all countries individually except Germany. In descending order, overall management costs were most sensitive to the relative costs of CT and EUS, the cost of LPB, and to the probability of no further testing when the "no EUS" strategy is used. However, threshold analysis showed that changes in only one variable, the ratio of the cost of EUS compared to CT (the "EUS/CT ratio"), were able to shift the optimal strategy from "no EUS" to "EUS." "EUS" becomes less costly only if the EUS/CT cost ratio is <0.85 (i.e., if the cost of EUS is <85% that of CT). If the potential for EUS to reduce severe complications caused by LPB of high risk lesions is incorporated, "EUS" is less costly if this risk is >2% (range 1-5%). CONCLUSIONS: When used to diagnose SMTs, EUS may reduce the need for further tests but not necessarily costs. For this indication, the relative cost of EUS compared with CT is what most limits its potential value as a cost-minimizing test. The costs, economic impact, and hence the relative appropriateness of EUS and other procedures may vary in different health care systems.

Adult↗