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Dive into the research topics where Yasunao Miyamoto is active.

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Featured researches published by Yasunao Miyamoto.


Journal of Gastroenterology and Hepatology | 2003

Balloon-occluded retrograde transvenous obliteration improves liver function in patients with cirrhosis and portal hypertension

Yasunao Miyamoto; Kazuhiko Oho; Masafumi Kumamoto; Atsushi Toyonaga; Michio Sata

Background and Aim:  Balloon‐occluded retrograde transvenous obliteration (B‐RTO) is a novel therapeutic method for the treatment of large gastric fundal varices with spontaneous splenorenal shunt (SRS). However, the effects of B‐RTO on liver function remain unknown.


Journal of Gastroenterology and Hepatology | 2010

Radiofrequency ablation therapy for hepatocellular carcinoma in elderly patients

Atsushi Hiraoka; Kojiro Michitaka; Norio Horiike; Satoshi Hidaka; Takahide Uehara; Soichi Ichikawa; Aki Hasebe; Yasunao Miyamoto; Tomoyuki Ninomiya; Ichiro Sogabe; Yoshihiro Ishimaru; Hideki Kawasaki; Yohei Koizumi; Masashi Hirooka; Yoshimasa Yamashita; Masanori Abe; Yoichi Hiasa; Bunzo Matsuura; Morikazu Onji

Background and Aim:  With the aging of society, the number of elderly patients with hepatocellular carcinoma (HCC) has been increasing in Japan. The Government of Japan defines elderly as being over 65 and has divided the elderly into two stages: the first elderly stage (< 75 years old) and the second elderly stage (≥ 75). We investigated the efficacy and safety of radiofrequency ablation therapy (RFA) in patients in the second elderly stage in comparison with other HCC patients, retrospectively.


Hepatology Research | 2010

Amino acid imbalance in patients with chronic liver diseases.

Kojiro Michitaka; Atsushi Hiraoka; Misaki Kume; Takahide Uehara; Satoshi Hidaka; Tomoyuki Ninomiya; Aki Hasebe; Yasunao Miyamoto; Misa Ichiryu; Tetsuya Tanihira; Hiromasa Nakahara; Hironori Ochi; Atsushi Tanabe; Kazuhiro Uesugi; Yoshio Tokumoto; Toshie Mashiba; Masanori Abe; Yoichi Hiasa; Bunzo Matsuura; Morikazu Onji

Aim:  The aim of this study is to clarify the amino acid imbalance in patients with chronic hepatitis (CH) as well as those with liver cirrhosis (LC).


Oncology | 2015

Tumor Markers AFP, AFP-L3, and DCP in Hepatocellular Carcinoma Refractory to Transcatheter Arterial Chemoembolization.

Atsushi Hiraoka; Yoshihiro Ishimaru; Hideki Kawasaki; Toshihiko Aibiki; Tomonari Okudaira; Akiko Toshimori; Tomoe Kawamura; Hiroka Yamago; Hiromasa Nakahara; Yoshifumi Suga; Nobuaki Azemoto; Hideki Miyata; Yasunao Miyamoto; Tomoyuki Ninomiya; Masashi Hirooka; Masanori Abe; Bunzo Matsuura; Yoichi Hiasa; Kojiro Michitaka

Background/Aim: We examined tumor marker levels to assess in more detail transcatheter arterial chemoembolization (TACE)-refractory hepatocellular carcinoma (HCC). Materials and Methods: We enrolled patients treated from 2000 to 2011 for HCC beyond the Milan criteria who had good hepatic reserve function (Child-Pugh A) and no portal vein thrombosis or metastases (n = 154). The modified criteria for being TACE-refractory according to the Liver Cancer Study Group of Japan (m-LCSGJ), from which the tumor marker item was excluded, and the Assessment for Retreatment with TACE (ART) score were used for determining whether the HCC was TACE refractory. α-Fetoprotein ≥100 ng/ml, fucosylated α-fetoprotein ≥10%, and des-gamma-carboxy prothrombin ≥100 mAU/ml were used to define whether tumor markers were positive. We added up the number of positive tumor markers as a prognostic score to assess in more detail the evaluation of TACE-refractory HCC. Results: In order to divide the patients into a refractory and nonrefractory group, the m-LCSGJ criteria [mean survival time (MST) 27.1 vs. 49.9 months; p < 0.001] were superior to the ART score (MST 22.0 vs. 35.1 months; p = 0.051). In the refractory group according to the m-LCSGJ criteria, the patients with a low score of positive tumor markers (<2) after 2 sessions of TACE (n = 36) showed a better prognosis than the others (n = 72) (MST 37.7 vs. 23.2 months; p = 0.014). Conclusion: Patients being nonrefractory according to the m-LCSGJ criteria had a better response, and using the number of tumor markers (≥2) is an easy method for predicting the response to TACE and for a more detailed evaluation of TACE-refractory HCC.


European Journal of Radiology | 2015

Prognosis and therapy for ruptured hepatocellular carcinoma: Problems with staging and treatment strategy

Atsushi Hiraoka; Tomoe Kawamura; Toshihiko Aibiki; Tomonari Okudaira; Akiko Toshimori; Hiroka Yamago; Hiromasa Nakahara; Yoshifumi Suga; Nobuaki Azemoto; Hideki Miyata; Yasunao Miyamoto; Tomoyuki Ninomiya; Tadashi Murakami; Yoshihiro Ishimaru; Hideki Kawasaki; Masashi Hirooka; Masanori Abe; Bunzo Matsuura; Yoichi Hiasa; Kojiro Michitaka

BACKGROUND There are no clear criteria established for treating a ruptured hepatocellular carcinoma (HCC). To elucidate the clinical features of affected patients, we examined prognosis and therapy choices. MATERIALS/METHODS We enrolled 67 patients treated for a ruptured HCC (HCV 44, HBV 5, HBV+HCV 1, alcohol 2, others 15; naïve HCC 34, recurrent 33) from 2000 to 2013, and investigated their clinical background and prognosis. RESULTS Median survival time (MST) for all cases was 4 months. For patients who survived for more than 1 year after rupture, the percentages of Child-Pugh C and positive for portal vein tumor thrombosis (PVTT)/extrahepatic metastasis were less than for those who died within 1 year. Child-Pugh classification (A:B:C=14:15:5 vs. 4:9:20, P<0.001) was better, while the percentage of patients with multiple tumors was lower [19/34 (55.9%) vs. 29/33 (87.9%), respectively; P<0.001] in the naïve group. The 1- and 3-year survival rates were better in the naïve as compared to the recurrent group (60.6% and 33.3% vs. 12.6% and 0%, respectively; P<0.01). MST according to modified TNM stage (UICC 7th) calculated after exclusion of T4 factor of rupture, stage I was better than others (22.7 vs. (II) 2.2, (III) 1.2, and (IV) 0.7 months) (P=0.010). CONCLUSION In patients with a ruptured HCC, especially those with a single tumor, and without decompensated liver cirrhosis and PVTT/extrahepatic metastasis, better prognosis can be expected with curative treatment. The present naïve group included more of such cases than the recurrent group, indicating the effectiveness of curative therapy.


Hepato-gastroenterology | 2011

Recent trends of Japanese hepatocellular carcinoma due to HCV in aging society.

Atsushi Hiraoka; Satoshi Hidaka; Yukou Shimizu; Hiroki Utsunomiya; Yusuke Imai; Haruka Tatsukawa; Nayu Tazuya; Hiroka Yamago; Nobukazu Yorimitsu; Tetsuya Tanihira; Aki Hasebe; Yasunao Miyamoto; Tomoyuki Ninomiya; Hideki Kawasaki; Masashi Hirooka; Masanori Abe; Yoichi Hiasa; Bunzo Matsuura; Morikazu Onji; Kojiro Michitaka

BACKGROUND/AIMS The mean age of hepatocellular carcinoma (HCC) patients has increased (=65 years old). We want to identify the recent trend of the clinical features of HCC patients due to hepatitis C virus (HCV) (HCV-HCC). METHODOLOGY From 2000 to 2009, 855 naive HCC patients were admitted. HCV-HCC patients were divided into two groups, first period group (2000-04, n=270) and second period group (2005-09, n=343) and the clinical features of HCV-HCC were investigated. RESULTS There was no difference in gender, TNM stage and percentages of HCV-HCC between the periods. On the other hand, the ratio of HCV-HCC patients with worse liver function (Child-Pugh B or C), elderly (=75 years old) and the population of patients treated with low invasive radiofrequency ablation were increased (30.0% to 42.0%, 17.2% to 35.8% and 25.1% to 36.2%, respectively; p<0.01). The 1y-, 3y- and 5y-survival rate of HCV-HCC did not show differences (82.1%, 60.5% and 44.7% vs. 81.8%, 56.9% and 37.7%, respectively; p=0.219). CONCLUSIONS The ratio of aged HCV-HCC as well as HCV-HCC patients with worse liver function was increased. The less invasive treatment for HCC in these patients and the quick anti-viral treatment for HCV patients should be considered to avoid occurrence of HCC in Japan.


Journal of Diabetes | 2016

Ultrasonography screening for hepatocellular carcinoma in Japanese patients with diabetes mellitus

Atsushi Hiraoka; Marie Ochi; Rie Matsuda; Toshihiko Aibiki; Tomonari Okudaira; Tomoe Kawamura; Hiroka Yamago; Hiromasa Nakahara; Yoshifumi Suga; Nobuaki Azemoto; Hideki Miyata; Yasunao Miyamoto; Tomoyuki Ninomiya; Masashi Hirooka; Masanori Abe; Bunzo Matsuura; Yoichi Hiasa; Kojiro Michitaka

Effective surveillance for hepatocellular carcinoma (HCC) in diabetes mellitus (DM) has not been established. We elucidated the risk factors for HCC in DM patients.


Journal of Hepatology | 1999

Effect of transcatheter arterial chemoembolization on kidney hemodynamics and function in patients with cirrhosis and hepatocellular carcinoma

Ryohichi Nakano; Tadashi Iwao; Kazuhiko Oho; Naofumi Ono; Teruhiro Sakai; Masahiro Sato; Makoto Yamawaki; Yasunao Miyamoto; Kenji Sakai; Teiko Takeda; Osamu Tsuruta; Michio Sata; Atsushi Toyonaga

BACKGROUND/AIMS Transcatheter arterial chemoembolization (TACE) may have deleterious effect on the kidney in patients with cirrhosis and hepatocellular carcinoma. The aim of the study was to test this hypothesis. METHODS Twenty-four patients with cirrhosis and hepatocellular carcinomas were included. They consisted of 16 patients undergoing a single TACE and eight patients undergoing diagnostic angiography. Doppler ultrasonography was used to measure hepatic artery pulsatility index (HA-PI) and renal artery pulsatility index (RA-PI) before and 1 day and 10 days after the procedure. Similarly, kidney function was assessed by measuring creatinine clearance. In addition, plasma renin activity, noradrenaline, and endothelin-1 were also measured. RESULTS In patients receiving diagnostic angiography, no significant changes in HA-PI were observed after the procedure. In contrast, HA-PI increased significantly 1 day after the procedure (19%, p<0.01) in patients undergoing TACE, although it returned to baseline value 10 days after the procedure. In patients undergoing diagnostic angiography, no significant changes in RA-PI were observed after the procedure. Similarly, no detectable changes in RA-PI were noted in patients undergoing TACE. A transient small reduction in creatinine clearance was noted after the procedure in patients undergoing diagnostic angiography (-12%, p<0.05) and in those undergoing TACE (-11%, p<0.05). However, the effect was similar in the two groups (two-way ANOVA, p=0.72). No significant changes in plasma renin activity, noradrenaline, and endothelin-1 were observed after either diagnostic angiography or TACE. CONCLUSIONS These results suggest that TACE per se has no deleterious effect on the kidney hemodynamics and function in patients with cirrhosis and hepatocellular carcinoma.


Journal of Gastroenterology | 1999

UPRIGHT POSTURE BLUNTS POSTPRANDIAL SPLANCHNIC HYPEREMIA IN PATIENTS WITH CIRRHOSIS AND PORTAL HYPERTENSION

Tadashi Iwao; Kazuhiko Oho; Ryohichi Nakano; Makoto Yamawaki; Teruhiro Sakai; Masahiro Sato; Yasunao Miyamoto; Kenji Sakai; Michio Sata; Atsushi Toyonaga

Abstract: The aim of this study was to compare postprandial hemodynamic changes observed during assumption of the recumbent posture and upright posture in patients with cirrhosis and portal hypertension. Eleven patients with cirrhosis and portal hypertension were studied. Echo-Doppler examinations were performed to measure flow volume in the portal vein (PV), superior mesenteric artery (SMA), and splenic artery (SA) in the fasting condition. Collateral blood flow was indirectly calculated by determining the difference between the sum of SMA, SA, and PV blood flows. After these measurements were done, each patient received a standardized liquid meal and was then randomly assigned to either maintain supine or upright posture, in a crossover design, on 2 different days (recumbent day and upright day). On each study day, the above-mentioned measurements were repeated 30 min and 60 min after the meal. PV blood flow increased significantly after the meal on the recumbent day (P < 0.01) but not on the upright day (P = 0.78). Although there were significant postprandial increases in SMA blood flow on both study days (P < 0.01, P < 0.01), the effect was less pronounced on the upright day than on the recumbent day (P < 0.01). Postprandial SA blood flow showed no change on the recumbent day (P = 0.64), but decreased significantly on the upright day (P < 0.01). The calculated postprandial collateral blood flow increased significantly on the recumbent day (P < 0.05), but showed no change on the upright day (P = 0.53). These results suggest that the upright posture blunts postprandial splanchnic hyperemia in patients with cirrhosis and portal hypertension.


Gastroenterology | 2012

Mo1144 Efficacy of Diagnosis for Acute Cholecystitis With Contrast Enhanced Ultrasonography: Evaluation for Blood Flow of the Gall Bladder Wall

Hiroki Utsunomiya; Atsushi Hiraoka; Miki Kan; Yusuke Imai; Haruka Tatsukawa; Nayu Tazuya; Hiroka Yamago; Yuko Shimizu; Nobukazu Yorimitsu; Satoshi Hidaka; Tetsuya Tanihira; Aki Hasebe; Yasunao Miyamoto; Tomoyuki Ninomiya; Kojiro Michitaka

Aim/background: In early phase of acute cholecystitis (AC), ultrasonography (US) or enhanced computed tomography (CECT) sometimes do not show the typical findings. Therefore, its diagnosis is difficult in many patients. We evaluated the efficacy for diagnosis of AC with contrast enhanced US (CEUS). Methods: Subjects were 21 patients who were suspected for AC and 13 controls. B-mode US, CECT, and CEUS were performed in all of them. The symptoms of 21 patients, who were suspected for AC, were any one of upper abdominal pain and/or an attack of fever with elevation of the levels of white blood cell and/or C-reactive protein. B-mode US and CECT were reviewed for distension of GB, GB wall thickness, existence of debris in GB, pericholecystic fluid, subserosal edema, pericholecystic stranding. For diagnosis of AC by B-mode US, more than two findings of the three typical findings (distension of GB, GB wall thickness, existence of debris in GB) were necessary and distension of GB was an indispensable finding. Definitive diagnosis of AC was done by histopathological examination, the result of culture of bile juice from GB, and/or the typical finding of CECT including pericholecystic stranding. CEUS was performed with Perfulbutane (Sonazoid®). Movie video was recorded during the procedure and analysis was done with Receiver Operating Characteristic (ROC), that was focused on the GB wall in arterial phase of CEUS (20-60 seconds after injection of Sonazoid®). The results of analysis for ROC and clinical results were evaluated. Results: Nineteen of 21 patients, who were suspected for AC, were diagnosed as AC. Time intensity curve (TIC) was higher and acceleration time (ACT) was shorter in patients with AC than those without AC (4.50±2.31 vs. 2.34±1.26, P<0.01, and 8.2±2.4 vs. 15.8±7.1 seconds, P<0.01, respectively). These findings indicated the increase of the blood flow and the acceleration of the flow speed, respectively. Cut off values of TIC and ACT for diagnosis in ROC analysis were settled as >1.34, and as <15.8 respectively. With the cut off values of both TIC and ACT, seventeen patients were diagnosed as AC (17/19, 89.5%). Diagnostic value for AC with CEUS using above cut off values was equal to that of CECT (sensitivity and specificity: 89.5% and 100% vs. 73.7% and 100%, respectively). On the other hand, diagnostic value for AC of B-mode was worse (sensitivity and specificity: 21.1% and 100%). In five cases that could not be diagnosed by CECT, CEUS could diagnose them as AC. Conclusion: TIC was high and ACT was shortened in patients with AC. CEUS enabled the accurate diagnosis of AC in majority of patients whose findings of CECT or B-mode US were not typical with AC. CEUS was useful for the diagnosis of AC by analyzing TIC and ACT.

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