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Dive into the research topics where Hiroki Yamaue is active.

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Featured researches published by Hiroki Yamaue.


Annals of Surgery | 2003

Long-Term Prognosis After Treatment of Patients with Choledocholithiasis

Kazuhisa Uchiyama; Hironobu Onishi; Masaji Tani; Hiroyuki Kinoshita; Manabu Kawai; Masaki Ueno; Hiroki Yamaue

Objective This study was conducted to examine the long-term prognosis of after treatment of patients with choledocholithiasis, including the recurrence of lithiasis, and to thereby determine the best treatment modality for choledocholithiasis based on its pathological entity. Summary Background Data Choledocholithiasis can be caused by either primary bile duct stones that originate in the bile duct or by secondary bile duct stones that have fallen out of the gallbladder. The recurrence rates vary depending on the type of choledocholithiasis. Methods Two-hundred thirteen outpatients who were treated for choledocholithiasis from 1982 to 1996 were selected as subjects and monitored for a period ranging from 5 to 19 years (mean, 9.6 years). The 213 patients were divided into 3 groups: 87 patients who had undergone choledocholithotomy and T-tube drainage (including the use of the laparoscopic method), 44 patients who had undergone choledochoduodenostomy, and 82 patients whose stones were removed by endoscopic sphincterotomy (EST). Recurrence of lithiasis was examined for each type of treatment modality. Results Choledochoduodenostomy was performed in 44 cases for the purpose of preventing any recurrence. The recurrent rate was analyzed in 169 cases. Choledocholithiasis recurred in 17 of the 169 cases (10.1%). The remaining 152 patients that showed no recurrence of lithiasis were examined and compared. The diameter of the common bile duct measured during the initial treatment was more dilated in patients with recurrent lithiasis (16.6 ± 5.9 mm) than in patients without any recurrence (9.8 ± 4.9 mm; P < 0.05). Peripapillary diverticula were observed in 10 of the 17 patients with recurrent lithiasis (58.8%), and in 34 of the 152 nonrecurrent patients (22.3%), showing that diverticula were more common in recurrent cases (P < 0.05). Furthermore, while primary bile duct stones were found in 11 of the 17 cases with recurrent lithiasis (64.7%), primary stones were found in only 37 of the 152 nonrecurrent patients (24.3%), showing primary bile duct stones were also more common in recurrent patients (P < 0.05). The recurrent patients were examined by surgical procedure. Nine patients with choledocholithotomy and T-tube drainage had a recurrence (10.3%), and 8 patients in the EST group had a recurrence (9.8%). The recurrence rates for these procedures were higher than for cases with choledochoduodenostomy (recurrence rate: 0%, P < 0.05). In particular, lithiasis recurred in 5 of the 12 patients with T-tube drainage for primary bile duct stones (41.7%). Conclusion Although choledocholithotomy and T-tube drainage, including open and laparoscopic surgery, is presently a common procedure for choledocholithiasis, this procedure will not necessarily prevent a recurrence of the disease. For older patients with primary bile duct stones, choledochoduodenostomy or EST is recommended.


Surgical Endoscopy and Other Interventional Techniques | 2002

Effectiveness of the clinical pathway to decrease length of stay and cost for laparoscopic surgery

Kazuhisa Uchiyama; Katsunari Takifuji; Masaji Tani; Hironobu Onishi; Hiroki Yamaue

AbstractsBackground: Although clinical pathways have become popular strategies to improve the quality of medication in the field of laparoscopic surgeries, their economical effectiveness is not well defined. The aim of this study was to investigate the effect of clinical pathways for laparoscopic surgeries on cost and length of hospital stay. Methods: From January 2000 to June 2001, clinical pathways were introduced for laparoscopic surgeries, such as laparoscopic cholecystectomy (Lap. C, n = 210), laparoscopically assisted distal gastrectomy with Billroth-I reconstruction (Lap. B-I, n=33), and laparoscopically assisted colectomy (Lap. colon, n=34). We compared total lengths of hospital stay and the economical efficiency before and after pathway implementation at Wakayama Medical University Hospital. Results: The length of hospital stay in Lap. C was shortened from 7.8±2.6 (mean±SD) days to 6.9±2.0 days (p = 0.03) and the total costs during hospitalization decreased from ¥509,320±58,800 to ¥489,130±43,860 (p=0.009), resulting in less burden for patients. At the same time, the daily costs were increased from ¥66,230±8920 to ¥70,840±6820 (p=0.0001), indicating that more efficient medical care was being given to patients. Similar results were obtained in Lap. B-I and Lap. colon groups. Conclusions: In our study, the implementation of clinical pathways in the field of laparoscopic surgeries produced significant decreases in length of total hospital stay and cost while maintaining the quality of patient outcomes.n


Pancreas | 2002

Locoregional chemotherapy for patients with pancreatic cancer intra-arterial adjuvant chemotherapy after pancreatectomy with portal vein resection.

Hiroki Yamaue; Masaji Tani; Hironobu Onishi; Hiroyuki Kinoshita; Mikihito Nakamori; Shozo Yokoyama; Makoto Iwahashi; Kazuhisa Uchiyama

Introduction and Aims The survival of pancreatic cancer patients with portal vein resection is extremely poor due to the high incidence of liver metastasis. The occurrence of liver metastasis is decreased by locoregional arterial infusion after pancreatic surgery. Chemosensitivity tests can provide the basis for individualized chemotherapy in each patient and predict the clinical response. Therefore, the current study was designed to clarify whether locoregional chemotherapy based on the results of chemosensitivity tests has the clinical effects of preventing liver metastasis and improving survival for patients with portal vein resection. Methodology The resected specimens from 40 of 47 patients with resection of pancreatic cancer were assessed for chemosensitivity to various anticancer drugs. Fourteen patients underwent portal vein resection due to direct invasion, and nine of these patients received intra-arterial adjuvant chemotherapy on the basis of the results of MTT assay to prevent liver metastasis. The remaining five patients received no chemotherapy. Results None of the patients who received intra-arterial chemotherapy had liver metastasis, and this group of patients had improved survival. The mean survival of patients with intra-arterial chemotherapy was significantly longer than that of patients without chemotherapy (25.6 months with chemotherapy versus 9.4 months without chemotherapy). Conclusion A pilot study of postoperative intra-arterial chemotherapy showed the reduction of liver metastasis and improvement of survival among pancreatic cancer patients with portal vein resection.


International Journal of Gastrointestinal Cancer | 2001

Adenosquamous Carcinoma of the Pancreas: Successful Treatment with Extended Radical Surgery, Intraoperative Radiation Therapy, and Locoregional Chemotherapy.

Hiroki Yamaue; Hiroshi Tanimura; Hironobu Onishi; Masaji Tani; Hiroyuki Kinoshita; Manabu Kawai; Shozo Yokoyama; Kazuhisa Uchiyama

SummaryBackground. Adenosquamous carcinoma of the pancreas is a rare tumor with an extremely poor survival rate. No obvious evidence that multidisciplinary treatments improves the prognosis and survival has been reported.n Patient and Results. A 63-yr-old female with adenosquamous carcinoma of the pancreas underwent extended radical surgery, intraoperative radiation therapy, postoperative intraarterial chemotherapy, and external beam radiation therapy. The patient is alive at 40 mo after surgery with no recurrence.n Conclusions. Multidisciplinary treatments including aggressive surgery, intraoperative radiation therapy, and locoregional chemotherapy might improve the survival of patients with adenosquamous carcinoma of the pancreas to inhibit liver metastasis and local recurrence.


International Journal of Pancreatology | 2000

Solid and cystic tumor of the pancreas

Hiroki Yamaue; Hiroshi Tanimura; Yoshiharu Shono; Hironobu Onishi; Masaji Tani; Hideki Yamoto; Hiroyuki Kinoshita; Kazuhisa Uchiyama

SummaryBackground. Solid and cystic tumor (SCT) of the pancreas can be distinguished from other pancreatic neoplasms by its nearly exclusive occurrence in young women, and its favorable prognosis after complete resection.Methods. We experienced four cases with SCT of the pancreas, and analyzed these tumors by immuno-histochemical and electron microscopic studies, as well as genetic analysis of ras oncogene mutation.Results. The presented cases expressed the neuron-specific enolase in two cases, α1-antitrypsin and α1-antichymotrypsin in two cases, and vimentin in one case, which indicated that this tumor originates from pleuripotential embryonic stem cells. No patients had mutations of K-ras gene in codon 12, and further genetic analysis is required to predict the malignant potential.n Conclusion. SCT of the pancreas appears to have limited malignant potential and the metastatic ratio is not high, although the tumor has local invasion. Therefore, an aggressive surgical approach seems fully justified.


The American Journal of Gastroenterology | 2002

Gram-positive cocci are associated with the formation of completely pure cholesterol stones

Manabu Kawai; Makoto Iwahashi; Kazuhisa Uchiyama; Minoru Ochiai; Hiroshi Tanimura; Hiroki Yamaue

OBJECTIVE:Recently it has been reported that bacterial DNA has been detected in mixed cholesterol stones (cholesterol content < 95%), which were not previously believed to be related to bacteria, using the polymerase chain reaction (PCR). We examined bacterial DNA in pure cholesterol stones to clarify the mechanism of initiation or promotion of the formation of cholesterol gallstones.METHODS:We examined 69 gallstones (30 brown pigment stones, 21 pure cholesterol stones, and 18 mixed cholesterol stones). Bacterial DNA was extracted from the core of the gallstones and amplified by PCR. Bacteria species in gallstones were identified by DNA sequencing of the PCR products.RESULTS:Bacterial DNA was detected in 26/30 brown pigment stones (87%), in 12/21 pure cholesterol stones (57%) (cholesterol content = 100%), and in 12/18 mixed cholesterol stones (67%) (cholesterol content = 82–95%). Bacterial species in gallstones were identified by DNA sequencing of PCR products. Eighty percent of bacteria in brown pigment stones were gram-negative rods or anaerobes. In contrast, 100% of bacteria in pure cholesterol stones were gram-positive cocci. The bacteria in mixed cholesterol stones consisted of 40% gram-positive cocci, 50% gram-negative rods, and 10% anaerobes.CONCLUSIONS:It was strongly suggested that gram-positive cocci are associated with the formation of pure cholesterol stones.


Digestive Diseases and Sciences | 2002

Clinical features of ciliated foregut cyst of the gallbladder: A rare entity of cystic lesion in the gallbladder

Seiko Hirono; Hiroshi Tanimura; Shozo Yokoyama; Kazuhisa Uchiyama; Masaji Tani; Hironobu Onishi; Hiroki Yamaue

A ciliated cyst of foregut origin may arise in relation to the tracheobronchial tree (1), mediastinum (2), liver (3), pancreas (4), tongue (5), and upper digestive tract (6). To our knowledge, only three cases of gallbladder cyst lined by ciliated epithelium have been reported (7–9). Ciliated cysts are considered to be benign, but they are difficult to differentiate from malignant neoplasm preoperatively when radiological studies show a cystic structure in or adjacent to the gallbladder (7). Since magnetic resonance cholangiopancreatography (MRCP) effectively reveals bile duct cyst, liver cyst, and pancreatic cyst (10), we used MRCP for the diagnosis of this rare entity. We report a case of ciliated intramural cyst of the gallbladder and clarify the clinical significance in terms of clinical and pathological features.


Archives of Surgery | 2002

Indication and Procedure for Treatment of Hepatolithiasis

Kazuhisa Uchiyama; Hironobu Onishi; Masaji Tani; Hiroyuki Kinoshita; Masaki Ueno; Hiroki Yamaue


Archives of Surgery | 2003

Indications for Extended Hepatectomy in the Management of Stage IV Hilar Cholangiocarcinoma

Kazuhisa Uchiyama; Takehiro Nakai; Masaji Tani; Hironobu Onishi; Hiroyuki Kinoshita; Manabu Kawai; Masaki Ueno; Hiroki Yamaue


Hepato-gastroenterology | 2001

Clinical features and imaging diagnosis of biliary cystadenocarcinoma of the liver

Hiroyuki Kinoshita; Hiroshi Tanimura; Hironobu Onishi; Yasuo Kasano; Kazuhisa Uchiyama; Hiroki Yamaue

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Kazuhisa Uchiyama

Wakayama Medical University

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Hironobu Onishi

Wakayama Medical University

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Masaji Tani

Shiga University of Medical Science

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Hiroyuki Kinoshita

Wakayama Medical University

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Hiroshi Tanimura

Wakayama Medical University

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Manabu Kawai

Wakayama Medical University

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Masaki Ueno

Wakayama Medical University

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Shozo Yokoyama

Wakayama Medical University

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Makoto Iwahashi

Wakayama Medical University

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Katsunari Takifuji

Wakayama Medical University

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