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Dive into the research topics where Hitoshi Yamachika is active.

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Featured researches published by Hitoshi Yamachika.


Digestive Endoscopy | 1992

The Diagnosis of the Anomalous Connection of Pancreaticobiliary Ducts Without Biliary Dilatation—The Usefulness of US/EUS Serial Examination—

Kenji Yamao; Saburo Nakazawa; Junji Yoshino; Kazuo Inui; Hitoshi Yamachika; Naoto Kanemaki; Masao Fujimoto; Takao Wakabayashi; Sumio Matsumoto; Kose Segawa; Takashi Suzuki; Masahiro Mitake

The anomalous connection of the pancreaticobiliary duct (ACPBD) without accompanying dilatation of the bile duct (non‐dilated type of ACPBD) has recently been found to be associated with gallbladder cancer at a rather high rate. We analyzed the diagnostic process of 5 patients with non‐dilated type of ACPBD including 3 asymptomatic cases and reviewed the literature. Symptoms and laboratory data were not useful in detecting this type of lesion. All our patients were checked by ultrasonography for gallbladder lesions which are suggested by: wall thickening, multiple polyps, intramural gall stones, cholecystolithiaisis, and debris. ACT revealed only wall thickening of the gallbladder. An EUS revealed a high rate of ACPBD in addition to the ultrasonographic findings of gallbladder lesions obtained by US. An ERCP was effective in clearly demonstrating ACPBD, but was not so useful for the diagnosis of concomitant gallbladder lesions. Therefore, an US is considered to be a useful means for screening this disease, and EUS is useful as a procedure to follow in order to select patients with or without ACPBD, because EUS can be conducted on an outpatient basis and is highly sensitive in detecting ductal anomalies in ACPBD. Therefore, the US/EUS serial examination is thought to be an effective means for diagnosing this disease.


Digestive Endoscopy | 1997

Three‐dimensional Ultrasonography Using Ultrasonic Probes by the Transpapillary Approach for Diagnosis of Pancreatobiliary Diseases

Naoto Kanemakp; Saburo Nakazawa; Kazuo Inui; Junji Yoshino; Hitoshi Yamachika; Kazumu Okushima; Yuta Nakamura; Kenji Yamao

Abstract: Three‐dimensional (3D) intraductal ultrasonography (IDUS) is more useful than two‐dimensional IDUS for the diagnosis of pancreatobiliary disease. We investigated the advantages and disadvantages of the transpapillary approach for 3D‐IDUS using a newly developed system for pancreatobiliary application. In total 12 patients with a sufficiently wide orifice were examined, bile duct (BD) scanning being successful in 100% of attempted cases and main pancreatic duct (MPD) scanning in 85.7%. In all cases, acceptable radial and linear images were obtained and 3D diagnosis was accomplished. However, several primary problems were experienced; 1) The 3D probe is relatively inflexible, having a thick shaft and a long tip, such that insertion into the BD or MPD can be somewhat difficult; 2) Clear images of the BD or MPD wall were not always obtained because of artifacts produced by the 3D probe itself; 3) In some cases, linear images could not be reconstructed with BD or MPD scanning despite sufficiently clear radial scan images. In the future, development of new 3D probes with more flexible and thinner shafts, and shorter tips, should considerably enhance the diagnostic capacity of IDUS for the pancreatobiliary system.


Digestive Endoscopy | 1999

Assessment of Underlying Blood Vessels in Gastric Ulcers with Bleeding Episode by Endoscopic Color Doppler Ultrasonography

Junji Yoshino; Saburo Nakazawa; Kazuo Inui; Hitoshi Yamachika; Takao Wakabayashi; Taketo Okushimsa; Takashi Kobayashi; Hiroshi Nishio

We used endoscopic color Doppler ultrasonography to detect hemorrhagic gastric ulcer, and to determine whether this modality could show blood vessels present deep to ulcers and whether these vessels influenced clinical course. Subjects were 20 patients with hemorrhagic gastric ulcers which had visible vessels on the ulcer base endoscopically. In 11 of 20 patients (group P) color signals indicating blood flow were observed, in which a weak pulsatile wave was detected in five cases. In two operated cases the signals were confirmed as blood vessels histologically. The diameters of these vessels were over 0.35 mm. It was thought that in cases undetectable on endoscopic color Doppler ultrasonography (group N) the diameter of vessels was too narrow or the velocity of blood too slow. There were no differences in the clinical background of group P and group N. However, ulcer bleeding was more severe in group P cases (P<0.05). Many patients in whom blood flow was detected experienced repeated ulcer bleeding as well as ulcer recurrences. Patients with hemorrhagic ulcers and in whom ultrasonic imaging demonstrates blood flow should be managed with great care. (Dig Endosc 1999; 11: 231–235)


Digestive Endoscopy | 1992

A Case of Pancreatolithiasis Treated by a Combination of Endoscopic Extraction and Extracorporeal Shock Wave Lithotripsy

Kazumu Okushima; Saburo Nakazawa; Kenji Yamao; Junji Yoshino; Kazuo Inui; Hitoshi Yamachika; Naoto Kanemaki; Teruhiko Iwase; Katsuhiko Kishi; Masao Fujimoto; Masumi Watanabe; Ken Hirano; Kou Harada; Hironao Miyoshi; Yuji Nimura

We report on the case of a 50‐year‐old woman with idiopathic chronic calcifying pancreatitis and diabetes. An endoscopic retrograde pancreatography showed a stone with a diameter of 23 mm and multiple small stones in the head of the pancreas. An endoscopic pancreatic sphincterotomy was performed. However, the stone could not be removed endoscopically. So we performed an extracorporeal shock wave lithotripsy (ESWL) using a Tripter X1. The stone was located in the shock wave focus by fluoroscopy. Under intravenous sedation, the patient received 5 ESWL sessions (a total of 11700 shock waves with an energy of 18kv). ESWL permitted stone disintegration and successful endoscopic extraction of the fragments. Complete clearance in the main pancreatic duct was achieved. No severe complications were observed. After treatment, an improvement in the PFD test was seen. ESWL is an effective method for treatment of endoscopically unextractable pancreatic ductal stones.


Digestive Endoscopy | 1995

Application of peroral cholecystoscopy in a case of cholecystocolic fistula

Naoto Kanemaki; Saburo Nakazawa; Kenji Yamao; Junji Yoshino; Kazuo Inui; Hitoshi Yamachika; Masao Fujimoto; Takao Wakabayashi; Kazumu Okushima; Ken Hirano; Hironao Miyoshi; Norihito Taki; Kazuhisa Sugiyama; Akihiko Fuji; Toshiyuki Hattori

A patient with a cholecystocolic fistula, complicating cholecysto‐choledocholithiasis, was treated endoscopically with gallbladder observation by peroral cholecystoscopy (POCCS). The patient was a 71‐year‐old female admitted to our hospital for investigation and treatment of biliary stones and a cholecystocolic fistula. Endoscopic lithotripsy and extracorporeal shock wave lithotripsy (ESWL) were performed after endoscopic sphincterotomy, and the gallbladder was subsequently investigated using a duodenoscope/ cholangioscope of the mother and baby type. Full distension of the gallbladder with saline solution allowed POCCS observation of the entire surface. The gallbladder mucosa was smooth, and neither stones nor tumors were observed. Though the cholecystocolic fistula itself could not be observed, we concluded that it had resulted from cholecystitis. Peroral cholecystoscopy is thus a useful method of investigating the gallbladder in such cases.


Digestive Endoscopy | 1995

A New Peroral Cholecystoscopy Method Utilizing a Shape Memory Alloy Bending Catheter‐Report of Two Cases

Kenji Yamao; Saburo Nakazawa; Jyunji Yoshino; Kazuo Evui; Hitoshi Yamachika; Naoto Kanemaki; Masao Fujdioto; Hironao Miyoshi; Teruhiko Iwase; Norihito Taki

For the purpose of improving the ease and reliability of catheter insertion into the cystic duct and gallbladder, we developed a new combination method utilizing an ultrathin fiberscope (miniscope, 0.8 mm), a guidewire (0.25 inches) and a shape memory alloy, bendable, catheter (SMA catheter, 2.6 mm). The main feature of the SMA catheter, which incorporates a micro‐actuator, is that its tip can be bent by remote control as desired. The SMA catheter could be inserted successfully into the cystic duct using a guide‐wire under direct miniscope vision in two patients with gallbladder lesions.


Acta Gastro-Enterologica Belgica | 1993

INDICATION FOR ENDOSCOPIC RESECTION OF SUBMUCOSAL TUMOR BY ENDOSCOPIC ULTRASONOGRAPHY

Ichiro Yasuda; Saburo Nakazawa; Junji Yoshino; Kenji Yamao; Kazuo Inui; Hitoshi Yamachika; Naoto Kanemaki; Takao Wakabayashi; Masao Fujimoto; Masumi Watanabe; Koh Harada


Acta Gastro-Enterologica Belgica | 1996

A CASE OF INTRADUCTAL PAPILLARY ADENOMA WITH SCANT MUCIN PRODUCTION OF THE PANCREAS

Naoto Kanemaki; Saburo Nakazawa; Kenji Yamao; Junji Yoshino; Kazuo Inui; Hitoshi Yamachika; Kazuhisa Sugiyama; Yuta Nakamura; Sayoko Teramoto; Akihiko Fuji; Tadashi Shinagawa; Akimasa Nakao


Acta Gastro-Enterologica Belgica | 1996

CLINICAL STUDY OF ENDOSCOPIC TRANSPAPILLARY GALLBLADDER DRAINAGE FOR CYSTIC DUCT OBSTRUCTION BY IMPACTED GALLSTONES

Naoto Kanemaki; Saburo Nakazawa; Kenji Yamao; Junji Yoshino; Kazuo Inui; Hitoshi Yamachika; Masao Fujimoto; Takao Wakabayashi; Teruhiko Iwase; Hironao Miyoshi; Norihito Taki; Kazuhisa Sugiyama


Acta Gastro-Enterologica Belgica | 1997

ENDOSCOPIC ULTRASOUND GUIDED FINE NEEDLE ASPIRATION CYTOLOGY FOR THE DIAGNOSIS OF DIGESTIVE DISEASES (2ND REPORT) IN SPECIAL REFERENCE TO THE DIAGNOSIS AND TREATMENT OF SUBMUCOSAL TUMORS OF THE UPPER GASTROINTESTINAL TRACT

Sayoko Teramoto; Kenji Yamao; Saburo Nakazawa; Jyunji Yoshino; Kazuo Inui; Hitoshi Yamachika; Naoto Kanemaki; Takao Wakabayashi; Takashi Kobayashi; Kazuhisa Sugiyama; Hiroshi Nishio; Sumio Matsumoto; Yoshimune Horibe; Yoshihiro Imaeda

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Kenji Yamao

Fujita Health University

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Naoto Kanemaki

Fujita Health University

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Kazuo Inui

Fujita Health University

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Junji Yoshino

Fujita Health University

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Masao Fujimoto

Fujita Health University

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Teruhiko Iwase

Fujita Health University

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