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Featured researches published by Chiaki Yasui.


Cancer | 1997

Correlation of hepatitis virus serologic status with clinicopathologic features in patients undergoing hepatectomy for hepatocellular carcinoma

Naoki Yamanaka; Tsuneo Tanaka; Wataru Tanaka; Junichi Yamanaka; Chiaki Yasui; Nobukazu Kuroda; Masafumi Takada; Eizo Okamoto

This study investigated the relationship between clinicopathologic features and various viral serologies in patients who underwent hepatectomy in the treatment of hepatocellular carcinoma (HCC).


Journal of Gastroenterology and Hepatology | 2000

Clinicopathologic analysis of stage II–III hepatocellular carcinoma showing early massive recurrence after liver resection

Junichi Yamanaka; Naoki Yamanaka; Keiji Nakasho; Tsuneo Tanaka; Tatsuya Ando; Chiaki Yasui; Nobukazu Kuroda; Masafumi Takata; Shigeto Maeda; Kazuyuki Matsushita; Kunio Uematsu; Eizo Okamoto

Abstract Background and Aims: Prognosis after hepatectomy for hepatocellular carcinoma (HCC) has been improved by progress in the evaluation of hepatic functional reserve, surgical techniques and perioperative management. However, even when curative resection is performed at a relatively early stage, a considerable number of patients develop early intrahepatic and/or extrahepatic recurrence postoperatively. This study analyzed the clinicopathologic features of HCC with early recurrence.


Langenbeck's Archives of Surgery | 2001

Left hemihepatectomy with microsurgical reconstruction of the right-sided hepatic vasculature

Naoki Yamanaka; Chiaki Yasui; Junichi Yamanaka; Tatsuya Ando; Nobukazu Kuroda; Shigeto Maeda; Takaaki Ito; Eizo Okamoto

Abstract. Background: Right hemihepatectomy (RH) for proximal bile duct canceroccasionally results in liver failure. We report the feasibility of left hemihepatectomy (LH) with vascular reconstruction (VR) of the right-sided hilar vessels to preserve hepatic reserve. Methods: Among 110 patients with proximal bile duct cancer (PBC) treated between January 1980 and December 1998, 11 patients underwent LH with VR of eight portal veins and nine hepatic arteries, and 14 underwent RH with VR of four portal veins and one hepatic artery. Microsurgical techniques were used in 80% (8/10) of the hepatic arterial reconstructions. Results: Although operation time was significantly longer in the LH group, hospital mortality, blood loss and incidence of histologically cancer positive margin at the bilioenteric anastomotic site were similar in the two groups. Peak serum liver enzyme concentration was significantly higher in the LH group with longer inflow occlusion time, whereas peak serum total bilirubin concentration was significantly higher in the RH group, which had smaller liver remnant. No liver abscess occurred in any patients who underwent microvascular reconstructions. The cumulative survival of the LH group was worse than that of the RH group, in which the proportion of vascular invasion was lower, but not significantly. Conclusion: LH with right-sided microvascular reconstruction is technically possible and a feasible option when RH is likely to result in postoperative liver failure.


Journal of Gastroenterology | 2000

Viral serostatus and coexisting inflammatory activity affect metachronous carcinogenesis after hepatectomy for hepatocellular carcinoma. A further report.

Naoki Yamanaka; Masafumi Takada; Tsuneo Tanaka; Junichi Yamanaka; Chiaki Yasui; Tatsuya Ando; Shigeto Maeda; Kazuyuki Matsushita; Eizo Okamoto

Abstract: Little data are available regarding the effects of hepatitis virus serostatus and the severity of coexisting chronic inflammation on intrahepatic recurrence after hepatectomy for hepatocellular carcinoma (HCC). We investigated the extent to which these factors modified the prognosis of hepatectomized patients. A total of 274 patients treated in the period January 1981 to December 1996 were divided into three groups: anti-hepatitis C-positive (HCV; n = 144), hepatitis B surface antigen-positive and HCV antibody (Ab)-negative (HBsAg; n = 106), and HBsAg-negative and HCV Ab-negative (NBNC; n = 20). Positivity for HBV-related antibody in the HCV group was 76%. Histologic grading of inflammatory activity from coexisting hepatitis was determined according to Knodels histological activity index (HAI) scoring system. Post-hepatectomy crude survival rates and disease-free survival (DFS) rates were compared, according to tumor characteristics, between the three groups. In the patients overall and also in the patients with a single nodular HCC, the HCV group had significantly higher HAI scores and preoperative serum aspartate aminotransaminase (AST) levels than the other two groups. When the patients were limited to those with a single nodular HCC, the crude survival was similar in the three groups with comparable tumor characteristics; however, the DFS was different (NBNC > HBsAg > HCV). When the patients were further limited to those with a single nodular HCC without microscopic extracapsular spread, in whom removal of the tumor was expected to be microscopically complete, the difference in the DFS became more marked. Irrespective of the viral serostatus, better crude and disease-free survivals were observed in the patients with lower AST levels (≧50 IU/l) than in those with higher AST levels (>50 IU/l). In contrast, there were no differences in survivals and HAI scores according to the presence or absence of HBV-related antibody in the HCV group. From our univariate analysis, we can conclude that the severity of virally induced inflammation, which was well correlated with viral serostatus, may be a factor that affects intrahepatic recurrence, which is more likely to originate from metachronous carcinogenesis. Prior co-infection of HBV in HCV patients may not be an adverse risk factor for intrahepatic recurrence.


Pathology International | 2006

Oncocytic non-functioning endocrine tumor of the pancreas

Ayako Sugihara; Keiji Nakasho; Shinichi Ikuta; Tsukasa Aihara; Takashi Kawai; Hiroya Iida; Hidenori Yoshie; Chiaki Yasui; Masao Mitsunobu; Kiyohiko Kishi; Toshio Mori; Naoko Yamada; Koji Yamanegi; Hideki Ohyama; Nobuyuki Terada; Nobuyuki Ohike; Toshio Morohoshi; Naoki Yamanaka

Herein is presented the case of a malignant non‐functioning endocrine tumor of the pancreas with oncocytic features, and a discussion on the high incidence of malignancy in oncocytic endocrine pancreatic tumors. The patient was a 65‐year‐old woman who showed no paraneoplastic symptoms produced by functioning pancreatic endocrine tumors. The primary tumor was located in the body and tail of the pancreas, and had metastasized to the liver. Tumor cells were arranged in a ribbon‐like or trabecular pattern and had an abundant eosinophilic cytoplasm containing numerous mitochondria and neurosecretory granules. The cytoplasm of the tumor cells was intensely stained with an antimitochondrial antigen antibody. Most tumor cells stained positively with Grimelius stain and for chromogranin A. Some tumor cells also stained for synaptophysin. However, the tumor cells negatively stained for hormones such as insulin, glucagon, somatostatin, gastrin, vasoactive intestinal peptide and pancreatic polypeptide, for serotonin, and for pancreatic enzymes such as amylase and trypsin. Analysis of 18 oncocytic pancreatic endocrine tumors, consisting of those reported previously and that in the present case, suggests that the high incidence of malignancy in oncocytic endocrine tumors is associated with the high incidence of non‐functioning endocrine tumors among them, most of which are malignant.


Journal of Gastroenterology | 2000

Evolution of and obstacles in surgical treatment for hepatocellular carcinoma over the last 25 years: differences over four treatment eras.

Naoki Yamanaka; Masafumi Takata; Tsuneo Tanaka; Junichi Yamanaka; Chiaki Yasui; Tatsuya Ando; Nobukazu Kuroda; Shigeto Maeda; Eizo Okamoto

Abstract: This study was designed to clarify what differences the last 25 years have made in surgical results for patients with hepatocellular carcinoma (HCC). We examined results for 716 hepatectomized patients in four treatment eras: first era (1973–1980; n = 58), second era (1981–1985; n = 155), third era (1986–1990; n = 243), and fourth era (1991–1997; n = 260). Patient background, tumor characteristics, type of hepatectomy, treatment for intrahepatic recurrences, and surgical results in the four eras were compared by univariate analysis to clarify the factors that have contributed to or impeded progress in the surgical treatment of HCC. Although there were no significant chronological differences in liver pathology and surgical resectability, operative mortality was reduced to 2% in the fourth era, from 29% in the first era. With an increasing proportion of early-stage HCCs (TNM, stages I and II), the cumulative survival rate at 5 years improved in the course of the eras in our overall population of patients (12%, 31%, 38%, and 51%, respectively, for the first, second, third, and fourth eras) and in a subset of the population divided according to tumor stage. Also, we found a chronological improvement in the survival rate at 3 years after intrahepatic recurrence (10%, 28%, 36%, and 44%, respectively in the first second, third, and fourth eras). This improvement was associated with the establishment of an early detection program for intrahepatic recurrences. However, the recurrence rate was similar in any subset of the population through the four eras. Although this univariate study could not determine independent factors that contributed to the chronological progress in results for HCC surgery in the four eras, it is conceivable that the establishment of indication criteria for hepatectomy, an early detection program for primary and recurrent lesions, and the introduction of multimodal treatment for recurrence were contributory factors in this im-provement. A strategy for alleviating the frequent recurrences originating from posthepatectomy metachronous carcinogenesis remains to be established.


World Journal of Gastroenterology | 2011

Simultaneous bile duct and portal venous branch ligation in two-stage hepatectomy

Hiroya Iida; Chiaki Yasui; Tsukasa Aihara; Shinichi Ikuta; Hidenori Yoshie; Naoki Yamanaka

Hepatectomy is an effective surgical treatment for multiple bilobar liver metastases from colon cancer; however, one of the primary obstacles to completing surgical resection for these cases is an insufficient volume of the future remnant liver, which may cause postoperative liver failure. To induce atrophy of the unilateral lobe and hypertrophy of the future remnant liver, procedures to occlude the portal vein have been conventionally used prior to major hepatectomy. We report a case of a 50-year-old woman in whom two-stage hepatectomy was performed in combination with intraoperative ligation of the portal vein and the bile duct of the right hepatic lobe. This procedure was designed to promote the atrophic effect on the right hepatic lobe more effectively than the conventional technique, and to the best of our knowledge, it was used for the first time in the present case. Despite successful induction of liver volume shift as well as the following procedure, the patient died of subsequent liver failure after developing recurrent tumors. We discuss the first case in which simultaneous ligation of the portal vein and the biliary system was successfully applied as part of the first step of two-stage hepatectomy.


Kanzo | 1996

A report of resected mesenchymal hamartoma of the liver in adult.

Tatsuya Andoh; Eizou Okamoto; Naoki Yamanaka; Takeshi Oriyama; Kazutaka Furukawa; Tsuneo Tanaka; Nobutaka Ichikawa; Wataru Tanaka; Chiaki Yasui; Nobukazu Kuroda; Yoshihiro Kitayama; Masamichi Imakita; Toshihiro Okada; Yutaka Takaya

我々は,検診にてCA19-9の軽度上昇を指摘され,超音波にて偶然発見された成人の肝間葉性過誤腫を経験したので報告する.症例は47歳の女性である.超音波やCTにて肝のS6より肝外性に発育する大きさ7cmの腫瘍を認め,腫瘍は充実性の部分と嚢胞性の部分にて構成されていた.血管造影では腫瘍全体に濃染像が見られた,良性腫瘍を最も疑ったが,悪性腫瘍も否定できず手術を施行した.切除標本では大きさ7.5cm×7.5cmの境界明瞭で光沢のある充実性腫瘍で,内部に大小の嚢胞を認めた.組織像では主に豊富な線維結合織よりなり,その間に大小の血管あるいはリンパ管や,小胆管の増生を認めた.現在,術後3年であるが,再発兆候はない.肝間葉性過誤腫の本邦報告例は64例であり,このうち15歳以下の小児例が52例と大部分を占め,成人例はわずか12例に過ぎない.小児例では腫瘍の発育速度は早く,成人例では発育速度は緩慢であるも悪性腫瘍との鑑別も困難で,共に切除が第一選択の治療である.悪性化や転移例はなく予後良好であるが,3例の再発例があり注意を要する.


Hepatology Research | 2000

Dynamics of serum and tissue alkaline phosphatase activity after hepatectomy in normal and cirrhotic rat liver

Chiaki Yasui; Naoki Yamanaka; Takeshi Oriyama; Kazutaka Furukawa; Eizo Okamoto

Abstract To investigate the pathogenesis of bile stasis after partial hepatectomy in the cirrhotic liver, the activity of alkaline phosphatase in serum and liver tissue, as well as morphologic changes in the bile canaliculi, were compared between cirrhotic and normal rats. In the normal rats, and cirrhotic rats produced by intraperitoneal thioacetamide injection, blood and liver specimens were obtained before and 2, 7, and 14 days after 70% partial hepatectomy. Serum and liver tissue alkaline phosphatase (ALPase) activity, liver weight, and electron histochemical changes in the bile canaliculi and microvilli were assessed. The normal rats showed rapid regeneration and marked elevation in the serum hepatic and tissue ALPase with a peak on day 2. This was associated with the maximal bile canalicular dilation and increased pericanalicular lipid vesicles, but without the microvilli destruction. These changes were normalized by 14 days after hepatectomy. In contrast, in the cirrhotic rats, regeneration and elevation in the serum and tissue ALPase were delayed, and higher total bile acidemia persisted. The bile canaliculi with ectasia before hepatectomy underwent no further dilation, and was associated with marked destruction of the microvilli and weakened ALPase in the bile canalicular membrane. The pericanalicular lipid vesicles was sparse. Persistent cholestasis in the remnant cirrhotic liver after hepatectomy is closely linked to the morphologic derangement and ALPase activity in the intra- and peri-bile canalicular area, and serum ALPase is useful as an index monitoring bile secretory capacity of the remnant liver.


Archive | 1993

Intratumor Pressure in Hepatocellular Carcinoma

Tsuneo Tanaka; Eizo Okamoto; Naoki Yamanaka; Takeshi Oriyama; Kazutaka Furukawa; Eisuke Kawamura; Fumihito Tomoda; Nobutaka Ichikawa; Wataru Tanaka; Chiaki Yasui

Intratumor pressure and hepatic tissue pressure were measured intraoperatively in 50 patients with hepatocellular carcinoma. Changes in these pressure were monitored before and after individual occlusion of the proper hepatic artery and the portal vein. Our result indicated that intratumor pressure was regulated predominantly by hepatic arterial blood flow, and increased with tumor capsular formation. In contrast, hepatic tissue pressure was regulated predominantly by portal blood flow, and increased with portal vein pressure.

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Naoki Yamanaka

Hyogo College of Medicine

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Eizo Okamoto

Hyogo College of Medicine

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Tsukasa Aihara

National Defense Medical College

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Masao Mitsunobu

Hyogo College of Medicine

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Hidenori Yanagi

Hyogo College of Medicine

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Tsuneo Tanaka

Hyogo College of Medicine

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Hiroya Iida

Shiga University of Medical Science

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Nobukazu Kuroda

Hyogo College of Medicine

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Wataru Tanaka

Hyogo College of Medicine

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