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Dive into the research topics where Morio Sato is active.

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Featured researches published by Morio Sato.


CardioVascular and Interventional Radiology | 1998

Balloon-Occluded Retrograde Transvenous Obliteration for Gastric Varices: A Feasibility Study

Tetsuo Sonomura; Morio Sato; Kazushi Kishi; Masaki Terada; Yasukazu Shioyama; Masashi Kimura; Kenzo Suzuki; Yasumichi Kutsukake; Takashi Ushimi; Junji Tanaka; Seishu Hayashi; Satoshi Tanaka

AbstractPurpose: To evaluate the clinical feasibility of balloon-occluded retrograde transvenous obliteration (BORTO) for gastric varices. Methods: BORTO was performed in 14 patients with gastric varices due to liver cirrhosis. The gastric varices were confirmed by endoscopy, and their feeding and draining veins were identified by contrast-enhanced computed tomography (CT) and angiography. A 6 Fr Simmons-shaped balloon catheter was inserted into the gastrorenal shunt. The balloon was inflated, and 5% ethanolamine oleate iopamidol was infused slowly through the catheter. Patients were followed up with endoscopy and enhanced CT at 1 week, 1, 3, and 6 months after the procedure and every 6 months thereafter. Results: The gastric varices completely disappeared in 12 of 14 patients and was partially resolved in the remaining 2 patients. Neither a recurrence nor an aggravation of gastric varices were found. No major complications were experienced. Conclusion: BORTO is a safe and effective treatment for gastric varices.


Journal of Vascular and Interventional Radiology | 2009

Evaluation of Transcatheter Arterial Embolization with Gelatin Sponge Particles, Microcoils, and N-butyl Cyanoacrylate for Acute Arterial Bleeding in a Coagulopathic Condition

Takafumi Yonemitsu; Nobuyuki Kawai; Morio Sato; Hirohiko Tanihata; Isao Takasaka; Motoki Nakai; Hiroki Minamiguchi; Shinya Sahara; Yasuhiro Iwasaki; Yukihiro Shima; Maki Shinozaki; Toshio Naka; Masahiro Shinozaki

PURPOSE To evaluate the outcome of transcatheter arterial embolization with gelatin sponge particles, microcoils, and N-butyl cyanoacrylate (NBCA) for acute arterial hemorrhage in the setting of coagulopathy. MATERIALS AND METHODS Coagulopathy is defined by a platelet count less than 5 x 10(4)/microL and/or International Normalized Ratio (INR) greater than 1.5. Forty-six patients (31 male patients; mean age, 62 years) with acute arterial hemorrhage in a coagulopathic condition were treated by transcatheter arterial embolization with gelatin sponge particle, microcoils, and NBCA. RESULTS Because of failure of hemostasis or recurrent hemorrhage, 10 patients who underwent gelatin sponge particle embolization also received transcatheter arterial embolization with microcoils or NBCA embolization and two patients who underwent microcoil embolization also received transcatheter arterial embolization with NBCA. The gelatin sponge particle group consisted of 27 hemorrhagic arteries in 25 patients, the microcoil group had 20 in 20 patients, and the NBCA group had 16 in 13 patients. The mean platelet count and mean INR value were 5.8 x 10(4)/microL +/- 3.5 and 1.81 +/- 0.50, respectively. The primary hemostatic rate, recurrent hemorrhage rate, and mean treatment time for the gelatin sponge particle, microcoil, and NBCA groups were 67%, 23%, and 25 minutes +/- 10; 80%, 0%, and 37 min +/- 19; and 100%, 0%, and 9 min +/- 4, respectively. Primary and secondary hemostasis were achieved in 50 (80%) and 60 (95%) of the 63 hemorrhagic arteries, respectively. Three hemorrhagic arteries in which transcatheter arterial embolization failed were treated with surgical repair. CONCLUSIONS Although transcatheter arterial embolization with microcoils took a greater amount of time, transcatheter arterial embolization with NBCA or microcoils was more effective and feasible than that with gelatin sponge particle in terms of hemostasis and prevention of recurrent hemorrhage in a coagulopathic condition.


CardioVascular and Interventional Radiology | 1990

Percutaneous transluminal angioplasty in segmental obstruction of the hepatic inferior vena cava : long-term results

Morio Sato; Ryusaku Yamada; Ko Tsuji; Kazushi Kishi; Masaki Terada; Yasukazu Shioyama; Shozo Nomura

Percutaneous transluminal angioplasty (PTA) was performed in 8 patients with segmental obstruction of the hepatic inferior vena cava. Using Grüntzig balloon catheters, canalization and dilatation were initially successful in all 8 patients without any complications. In long-term observation of 12–48 months, recurrence of obstruction was confirmed in 5 patients. These were recanalized easily by repeat PTA. Long-term patency was obtained in 3 patients in whom the lumen was opened to 13 mm or more in diameter as seen in lateral views of the vena cavogram.


International Journal of Radiation Oncology Biology Physics | 2008

High-dose-rate brachytherapy of a single implant with two fractions combined with external beam radiotherapy for hormone-naive prostate cancer.

Morio Sato; Takashi Mori; Shintaro Shirai; Kazushi Kishi; Takeshi Inagaki; Isao Hara

PURPOSE To evaluate the preliminary outcomes of high-dose-rate (HDR) brachytherapy of a single implant with two fractions and external beam radiotherapy (EBRT) for hormone-naive prostate cancer. METHODS AND MATERIALS Between March 2000 and Sept 2003, a total of 53 patients with tumor Stage T1c-T3b N0 M0 prostate cancer were treated with HDR brachytherapy boost doses (7.5 Gy/fraction) and 50-Gy EBRT during a 5.5-week period. Median follow-up was 61 months. Patients were divided into groups with localized (T1c-T2b) and advanced disease (T3a-T3b). We used the American Society for Therapeutic Radiology and Oncology (ASTRO) definition for biochemical failure. According to recommendations of the Radiation Therapy Oncology Group-ASTRO Phoenix Consensus Conference, biochemical failure-free control rates (BF-FCRs) at 3 years were investigated as 2 years short of the median follow-up. RESULTS Between April 2000 and Sept 2007, Common Terminology Criteria for Adverse Events Version 2.0 late Grade 2 genitourinary and gastrointestinal toxicity rates were 0% and 3.8%, respectively. Erectile preservation was 25% at 5 years. Overall survival was 88.1% and cause-specific survival was 100%. At 3 years, ASTRO BF-FCRs of the localized and advanced groups were 100% and 42%, respectively (p = 0.001). CONCLUSIONS The HDR brachytherapy of a single implant with two fractions plus EBRT is effective in treating patients with localized hormone-naive prostate cancer, with the least genitourinary and gastrointestinal toxicities; however, longer median BF-FCR follow-up is required to assess these findings.


CardioVascular and Interventional Radiology | 1997

Dependency of tissue necrosis on gelatin sponge particle size after canine hepatic artery embolization

Tetsuo Sonomura; Ryusaku Yamada; Kazushi Kishi; Norifumi Nishida; Ren J. Yang; Morio Sato

PurposeTo determine the optimal size of gelatin sponge particles (GSPs) to produce maximum tumor necrosis with minimum side effects after canine hepatic artery embolization (HAE).MethodsGSPs were separated into four size ranges: A, up to 200 μm (mean 152) as Gelfoam powder; B, 200–500 μm (mean 336) as Gelfoam powder; C, 500–1000 μm (mean 649) as Spongel; and D, 1000–2000 μm (mean 1382) as Spongel. Three mongrel dogs were assigned randomly to HAE with each particle size. On day 7 after HAE, the livers were removed and subjected to pathological examination.ResultsThe mean volume of liver necrosis was 11% after embolization, with particle size A, 36.3% with B, 0% with C, and 1% with D. Coagulation necrosis was found in all livers with particles of sizes A and B, and in 1 of 6 with sizes C and D. Bile duct injury was found in five of six dogs with sizes A and B and in none with sizes C and D. Gallbladder necrosis was found in one dog with size B and pancreas necrosis in one with size A.ConclusionGSPs of 500 μm are considered optimally effective for tissue necrosis according to this model.


International Journal of Radiation Oncology Biology Physics | 2010

Feasibility and efficacy of single photon emission computed tomography-based three-dimensional conformal radiotherapy for hepatocellular carcinoma 8 cm or more with portal vein tumor thrombus in combination with transcatheter arterial chemoembolization.

Shintaro Shirai; Morio Sato; Kazuhiro Suwa; Kazushi Kishi; Chigusa Shimono; Tetsuo Sonomura; Nobuyuki Kawai; Hirohiko Tanihata; Hiroki Minamiguchi; Motoki Nakai

PURPOSE To assess the feasibility and efficacy of single photon emission computed tomography-based three-dimensional conformal radiotherapy (SPECT-B 3D-CRT) for large hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT). METHODS AND MATERIALS HCC patients with PVTT in the first branch or main trunk, 8 cm or greater in size, were admitted to the study. SPECT, using Tc-99m-galactosyl human serum albumin, was used in radiation treatment planning to explore the optimal irradiation beam angle. SPECT enabled the minimum possible irradiation of functional liver (FL). Clinical target volume (CTV) included the main tumor and PVTT. SPECT-B 3D-CRT targeted the CTV to a total dose of 45 Gy/18 fractions. HCC outside the CTV was treated by transcatheter arterial chemoembolization (TACE). RESULTS Nineteen cases were enrolled in this study. The mean maximum dimension, mean CTV, and mean dose to FL were 11.0 cm (range, 8.0-20.0), 435 cm(3) (range, 60-2,535), and 1,102 cGy (range, 691-1,695), respectively. Follow-up SPECT demonstrated radiation-induced dysfunctional liver. Despite the inclusion of 6 cases of Child-Pugh B or C, no patients experienced Grade 3 or worse radiation-induced liver disease. The cumulative non-progression rates of PVTT and PVTT plus main tumor were 78.0 and 43.2%, respectively. Survival rates at 1 and 2 years were 47.4 and 23.7%, respectively. CONCLUSIONS SPECT-B 3D-CRT with TACE appears to be tolerable to cirrhotic liver and to provide promising prognosis for patients with HCC sized 8 cm or more, in comparison with previous treatment methods. A longer follow-up period is required to evaluate these findings.


CardioVascular and Interventional Radiology | 1993

Effects of hepatic artery embolization with lipiodol and gelatin sponge particles on normal swine liver

Morio Sato; Ryusaku Yamada; Barry T. Uchida; Penny Hedgepeth; Josef Rösch

In order to evaluate the effects of hepatic artery embolization (HAE) with Lipiodol (Lp) and gelatin sponge particles (GSP) on swine liver tissue, we embolized the hepatic arteries of 3 pigs with GSP, 9 with Lp, and 9 with Lp+GSP. None of the pigs embolized with GSP died spontaneously during the 4-week experimental period. One pig embolized with 1 ml/kg Lp and three pigs with 2 ml/kg Lp died within 2 h. Two pigs embolized with 0.5 ml/kg Lp+GSP died the following day. The portal vein pressure (PVP) and wedge hepatic vein pressure (WHVP) values before HAE, immediately after, 1 h after, and 4 weeks after HAE showed no remarkable change in the GSP group. Remarkable and temporary elevation was observed in the more than 0.2 ml/kg Lp group. Remarkable and continuous elevation was observed in the 0.2 ml/kg Lp+GSP and 0.5 ml/kg Lp+GSP groups. Gross and histological studies demonstrated no liver damage in the GSP and Lp group. Liver infarction, circular coagulation necrosis with pseudocapsule, and liver atrophy were found in the Lp+GSP group 4 weeks after HAE. The incidence of infarction, circular coagulation necrosis, and liver atrophy in the livers embolized with 0.2 ml/kg Lp+GSP and 0.5 ml/kg Lp+GSP were 67%, 100%, and 75%, respectively. In conclusion, when the hepatic artery is embolized with Lp+GSP, the volume of Lp should be limited to less than 0.1 ml/kg.


CardioVascular and Interventional Radiology | 2001

Endoluminal treatment of ruptured abdominal aortic aneurysm with small intestinal submucosa sandwich endografts: a pilot study in sheep.

Katsuyuki Yamada; Dusan Pavcnik; Barry T. Uchida; Hans A. Timmermans; Christopher L. Corless; Qiang Yin; Koichiro Yamakado; Joong Wha Park; Josef Rösch; Frederick S. Keller; Morio Sato; Ryusaku Yamada

PurposeTo evaluate efficacy of small intestinal submucosa (SIS) Sandwich endografts for the treatment of acute rupture of abdominal aortic aneurysms (AAA) and to explore the short-term reaction of the aorta to this material.MethodsIn eight adult sheep, an infrarenal AAA was created transluminally by dilation of a short Palmaz stent. In six sheep, the aneurysm was then ruptured by overdilation of the stent with a large angioplasty balloon. Two sheep with AAAs that were not ruptured served as controls. A SIS Sandwich endograft, consisting of a Z stent frame with 5 bodies and covered inside and out with SIS, was used to exclude the ruptured and non-ruptured AAAs. Follow-up aortography was done immediately after the procedure and before sacrifice at 4, 8, or 12 weeks. Autopsy and histologic studies followed.ResultsEndograft placement was successful in all eight sheep. Both ruptured and non-ruptured AAAs were successfully excluded. Three animals with AAA rupture developed hind leg paralysis due to compromise of the arterial supply to the lower spinal cord and were sacrificed 1 day after the procedure. In five animals, three with rupture and two controls, follow-up aortograms revealed no aortic stenoses and no perigraft leaks. Gross and histologic studies revealed incorporation of the endografts into the aortic wall with replacement of SIS by dense neointima that was completely endothelialized in areas where the endograft was in direct contact with the aortic wall. In central portions of the endograft, in contact with the thrombosed aneurysm, endothelialization was incomplete even at 12 weeks.ConclusionThe SIS Sandwich endografts effectively excluded simple AAAs and ruptured AAAs. They were rapidly incorporated into the aortic wall. A detailed long-term study is warranted.


CardioVascular and Interventional Radiology | 1996

Post-TIPS hepatic encephalopathy treated by occlusion balloon-assisted retrograde embolization of a coexisting spontaneous splenorenal shunt

Yasukazu Shioyama; Kiyoshi Matsueda; Koushi Horihata; Masashi Kimura; Norifumi Nishida; Kazushi Kishi; Masaki Terada; Morio Sato; Ryusaku Yamada

A 51-year-old man with posthepatitis cirrhosis underwent a transjugular intrahepatic portosystemic shunt (TIPS) for bleeding of recurrent esophageal varices. The patient had a coexisting, spontaneous, splenorenal shunt. He subsequently developed hepatic encephalopathy, presumably due to excessive portosystemic shunting. Since medical management resulted in no significant improvement, the splenorenal shunt was embolized from the jugular vein approach via renal vein access during temporary balloon occlusion. Within a few days, the patients hepatic encephalopathy resolved. Twelve months later the patient showed no recurrence of encephalopathy and had maintained a patent TIPS.


International Journal of Radiation Oncology Biology Physics | 1995

Effect of balloon occluded arterial infusion of anticancer drugs on the prognosis of cervical cancer treated with radiation therapy

Koh Tsuji; Ryusaku Yamada; Mamoru Kawabata; Kiyoshi Mitsuzane; Morio Sato; Masaaki Iwahashi; Shunya Kitayama; Ryosuke Nakano

PURPOSE The effect of local injection of anticancer drugs by balloon catheter, i.e., balloon occluded arterial infusion (BOAI), on the prognosis of cervical cancer treated with radiotherapy were retrospectively estimated. METHODS AND MATERIALS Sixty-five patients with cervical cancer (Stage I-IV) treated by irradiation were included in the study. Among the 65 cases, 2 were in Stage I, 13 in Stage II, 40 in Stage III, and 10 in Stage IV. Patients who received surgical resection were excluded. Thirty-nine patients received BOAI and 44 received brachytherapy. Twenty-six patients were not indicated for BOAI because of insufficient renal function, hepatic complications, hematological complications, and refusal from the patients. Cisplatin (0.9-1.7 mg/kg), Adriamycin (0.7-0.9 mg/kg), and Pepleomycin (0.4-0.6 mg/kg) were administered simultaneously into the bilateral internal iliac arteries by BOAI. External irradiation was given by 10 MV x-ray. Total dose administered to the regional lymph nodes by the external irradiation was 48.3 +/- 8.7 Gy. Radium was used at brachytherapy. The dose delivered by the brachytherapy at point A was 45.3 +/- 14.9 Gy. Patients without brachytherapy received 26.1 +/- 19.1 Gy of boost irradiation by the external photon beam. The survival probabilities of the patients were calculated by Kaplan-Meier method. RESULTS The 5-year survival rates of the Stage III patients with and without BOAI were 53 +/- 13% and 24 +/- 18%, respectively (p = 0.036). By multivariate analyses using Coxs proportional hazard model, stage and BOAI were selected as significant predictors of the prognosis. Transient bone marrow suppression was observed in about half of the patients with BOAI. No significant increase of the incidence of the late radiation damage by BOAI in rectum or in urinary bladder was observed. CONCLUSION Balloon occluded arterial infusion of anticancer drugs may improve the prognosis of the patients with cervical cancer without increasing the incidence of the late radiation damage. A larger scale prospective randomized study is desired.

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Tetsuo Sonomura

Wakayama Medical University

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Nobuyuki Kawai

Tokyo Institute of Technology

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Motoki Nakai

Wakayama Medical University

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Kazushi Kishi

Wakayama Medical University

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Hiroki Minamiguchi

Wakayama Medical University

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Akira Ikoma

Wakayama Medical University

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Kouhei Nakata

Wakayama Medical University

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Hiroki Sanda

Wakayama Medical University

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Shintaro Shirai

Wakayama Medical University

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