Osamu Sato

Japanese Red Cross Kyoto Daiichi Hospital, Kioto, Kyōto, Japan

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Publications (18)18.1 Total impact

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    ABSTRACT: Objective: The purpose of this study was to retrospectively compare the subclavian and femoral approaches to a fixed-catheter-tip method of implantation of a port-catheter system for hepatic arterial infusion chemotherapy with respect to complications and dysfunctions. Materials and methods: Between April 2006 and April 2012, 153 patients (104 men, 49 women; age range, 23-82 years; mean, 65 years) with unresectable malignant liver tumors underwent percutaneous implantation of indwelling port-catheter systems by the fixed-catheter-tip method via the left subclavian or femoral artery. The success of implantation and outcome of complications were investigated and compared between these approach routes. Results: The overall technical success rate of port-catheter system implantation with the fixed-catheter-tip method was 99% (152 of 153 patients). Seventy-five patients underwent implantation with a port-catheter system via the left subclavian artery, and 77 patients via the femoral artery. Catheter dislocation occurred in 3.9% of the patients; hepatic artery obstruction, 2.6%; catheter occlusion, 3.9%; bleeding at the puncture site, 3.9%; cerebral infarction, 1.3%; and infection related to port-catheter implantation, 2.6%. No significant differences in complications and port-catheter system dysfunction between the left subclavian and femoral approaches to port-catheter system implantation with the fixed-catheter-tip method were seen in any of the parameters. In addition, cerebral infarction occurred exclusively with the left subclavian approach, whereas infection occurred exclusively with the femoral approach. Conclusion: Implantation of the port-catheter system with the fixed-catheter-tip method is equally feasible via both the left subclavian and the femoral approaches.
    American Journal of Roentgenology 01/2014; 202(1):211-5. DOI:10.2214/AJR.12.10502 · 2.73 Impact Factor
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    ABSTRACT: To investigate the feasibility, efficacy, and safety of transcatheter arterial embolization with N-butyl cyanoacrylate (NBCA) for gastroduodenal nonvariceal bleeding uncontrolled by endoscopic hemostasis. Between January 2006 and December 2011, a total of 317 patients underwent emergent endoscopic therapy for nonvariceal gastroduodenal bleeding, but hemostasis was not achieved in 20 cases. Emergent surgery was performed immediately following endoscopy in two patients. Arteriography was performed in the remaining 18 patients, and embolization with NBCA was performed in 15 patients (mean age, 71.3 y) in whom the bleeding site was detected on arteriography. For embolization, NBCA was mixed with iodized oil at a ratio of 1:1.5-1:4, and no other embolic material was used in the procedure. Technical and clinical success rates, recurrent bleeding, procedural time, complications, and clinical outcomes were determined for each procedure. Embolization with NBCA was technically and clinically successful in all procedures, without major complications. No patient receiving embolization with NBCA experienced recurrent bleeding or required further treatment after the one-session procedure. All patients were discharged after clinical improvement. The time between puncture of the femoral artery and completion of embolization ranged from 25 to 240 minutes (mean, 66 min), and the time between the microcatheter reaching the ultimate catheter location selected for embolization and hemostasis ranged from 142 to 550 seconds (mean, 322s). In this limited series, embolization with NBCA was found to be a safe, feasible, and effective treatment for gastroduodenal arterial bleeding when endoscopic hemostasis had failed.
    Journal of vascular and interventional radiology: JVIR 03/2013; 24(3):432-8. DOI:10.1016/j.jvir.2012.12.017 · 2.41 Impact Factor
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    ABSTRACT: A persistent left superior vena cava (PLSVC) is the most common thoracic venous anomaly, and we should be aware of its existence. We encountered a case of significant left arm swelling due to recurrent left subclavian venous stenosis in a hemodialysis patient with a PLSVC. Endovascular stent placement was performed safely and effectively for the stenosis employing the pull-through technique, in which a guidewire was passed from the left internal jugular vein to the access vein. On the following day, left arm swelling had improved. 3 months after stent placement the left arm swelling has not recurred.
    Annals of Vascular Diseases 01/2012; 5(1):85-8. DOI:10.3400/avd.cr.11.00061
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    ABSTRACT: Reports on CT-guided percutaneous drainage within the intervertebral space for pyogenic spondylodiscitis with a secondary psoas abscess are limited. To evaluate CT-guided percutaneous drainage within the intervertebral space for pyogenic spondylodiscitis and a secondary psoas abscess in which the two sites appear to communicate. Eight patients with pyogenic spondylodiscitis and a secondary psoas abscess showing communication with the intradiscal abscess underwent CT-guided percutaneous drainage within the intervertebral space. The clinical outcome was retrospectively assessed. An 8-French pigtail catheter within the intervertebral space was successfully placed in all patients. Seven patients responded well to this treatment. The one remaining patient who had developed septic shock before the procedure died on the following day. The mean duration of drainage was 32 days (13-70 days). Only one patient with persistent back pain underwent surgery for stabilization of the spine after the improvement of inflammation. Among seven patients responding well, long-term follow-up (91-801 days, mean 292 days) was conducted in six patients excluding one patient who died of asphyxiation due to aspiration unrelated to the procedure within 30 days after the procedure. In these six patients, no recurrence of either pyogenic spondylodiscitis or the psoas abscess was noted. CT-guided percutaneous drainage within the intervertebral space can be effective for patients with pyogenic spondylodiscitis and a secondary psoas abscess if the psoas abscess communicates with the intradiscal abscess.
    Acta Radiologica 12/2011; 53(1):76-80. DOI:10.1258/ar.2011.110418 · 1.60 Impact Factor
  • Journal of vascular and interventional radiology: JVIR 11/2011; 22(11):1631-3. DOI:10.1016/j.jvir.2011.07.003 · 2.41 Impact Factor
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    ABSTRACT: Although n-butyl-2-cyanoacrylate (NBCA) has been used as an effective liquid embolization material, its indication for pseudoaneurysms has seemingly been limited because of the technical difficulties of using NBCA, such as reflux to the parent artery and causing significant infarction. Thus, considerable skill in using NBCA or a device to control blood flow during its polymerization is required to achieve embolization without severe complications. We report our new technique for controlling blood flow using diluted epinephrine in transcatheter arterial NBCA embolization of five pseudoaneurysms in four cases secondary to hemosuccus pancreaticus.
    CardioVascular and Interventional Radiology 10/2011; 35(4):932-7. DOI:10.1007/s00270-011-0294-8 · 2.07 Impact Factor
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    ABSTRACT: We encountered a rare case of spontaneous rupture of the omental artery. A 25-year-old man without any episode of abdominal trauma or bleeding disorders came to the emergency unit with left upper abdominal pain. Hematoma with extravasation of the greater omentum and a hemoperitoneum was confirmed on abdominal contrast-enhanced computed tomography. Bleeding from the omental artery was suspected based on these findings. Transcatheter arterial embolization was successfully performed after extravasation of the omental artery, which arises from the left gastroepiploic artery, was confirmed on arteriography. Partial ometectomy was performed 10 days after transcatheter arterial embolization, revealing that the hematoma measured 10 cm in diameter in the greater omentum. Pathological examination showed rupture of the branch of an omental artery without abnormal findings, such as an aneurysm or neoplasm. Thus, we diagnosed him with spontaneous rupture of the omental artery. The patient recovered and was discharged from the hospital 10 days after the surgery, with a favorable postoperative course.
    CardioVascular and Interventional Radiology 02/2011; 34 Suppl 2(S2):S142-5. DOI:10.1007/s00270-010-9956-1 · 2.07 Impact Factor
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    ABSTRACT: Symptomatic penetration of the inferior vena cava (IVC) wall reportedly occurs in 0.3% of patients in whom a filter has been implanted, and it causes injury to the adjacent structures (Bogue et al. in Pediatr Radiol 39(10):1110-1113, 1; Brzezinski et al. in Burns 32(5):640-643, 2). We succeeded in the endovascular repair of perforation of the IVC wall occurring during the retrieval of a penetrated Gunther tulip vena cava filter (Cook, Bjaeverskov, Denmark) after long-term implantation.
    CardioVascular and Interventional Radiology 02/2011; 34 Suppl 2(S2):S321-3. DOI:10.1007/s00270-010-0053-2 · 2.07 Impact Factor
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    ABSTRACT: The purpose of our investigation was to determine if injection of prostaglandin E(1) during CT hepatic arteriography could help physicians to distinguish tumors from nonportal venous flow-related pseudolesions in the region of the gallbladder fossa. In 34 patients who underwent CT during arterial portography to detect liver tumors, CT hepatic arteriography was performed before and after prostaglandin E(1) injection via the superior mesenteric artery. Between each study, an interval of 10 minutes was set. On CT hepatic arteriogram obtained 15 to 20 sec after prostaglandin E(1) injection, we distinguished changes in the size and shape of pseudolesions in the liver around the gallbladder as well as those of 42 tumorous lesions. In addition, we measured the change in CT attenuation of pseudolesions. The size of the enhanced area of pseudolesions visible on CT hepatic arteriography decreased in 69% (25/36) of the pseudolesions after intraarterial prostaglandin E(1) injection, with the mean diameter diminishing from 14.1 mm to 8.8 mm. Notably, in 11 pseudolesions, the enhanced area disappeared. In 86% (31/36), the CT attenuation decreased with the mean attenuation, diminishing from 211.3 H to 163.8 H. However, the size and shape of the enhanced area of tumorous lesions did not change. The hemodynamic features of pseudolesions on angiographically assisted helical CT scans caused by cholecystic venous inflow are easily influenced by increased portal venous flow. Consequently, pseudolesions around the gallbladder usually can be distinguished from tumorous lesions by adding prostaglandin E(1) injection via the superior mesenteric artery during CT hepatic arteriography.
    American Journal of Roentgenology 08/2001; 177(1):115-9. DOI:10.2214/ajr.177.1.1770115 · 2.73 Impact Factor
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    ABSTRACT: Clinical trials of TAE using microcoils (Target, USA) coated with n-butyl 2-cyanoacrylate and lipiodol were performed. The procedures were as follows. First, a small amount of lipiodol was injected into a Tracker 18 catheter. Secondly, a microcoil coated with n-butyl 2-cyanoacrylate and lipiodol was inserted into the microcatheter. Thirdly, a small amount of lipiodol was again administered into the catheter just behind the coil. Finally, the coil was pushed safely out from the catheter with a special guidewire. With this method, excellent occlusion of small arteries was obtained. There were no complications.
    Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 12/1994; 54(13):1309-11.
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    ABSTRACT: We analyzed the safety of the segmental-subsegmental TAE for hepatocellular carcinoma in 18 cases of liver hypofunction by checking total bilirubin change after TAE. The TAE was performed safely in all of the cases. The highest value of total bilirubin before TAE was 5.1 mg/dl in the 1-2 subsegment TAE group, 3.8 mg/dl in the 3-4 subsegment TAE group and 2.0 mg/dl in the 6 subsegment TAE group. We conclude that segmental TAE is safe even in the patient of liver hypofunction.
    Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 08/1994; 54(8):798-800.
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    ABSTRACT: We tried to use nitroglycerin to enhance MR angiography (MRA). Nitroglycerin has an effect to dilate vessels. We made a direct comparison between pre and post enhanced MRA (3 D-TOF technique). MRA after administration of nitroglycerin could depict more details of cortical branches without enhancement of background. So we recommend this method to be used in any examination of MR angiography.
    Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 06/1993; 53(5):593-5.
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    ABSTRACT: Transcatheter embolization therapy using absolute ethanol was accomplished in six patients with renal arteriovenous malformation. The effect of this therapy was considered to be good, because none of the patients has experienced recurrent hematuria. It is necessary to avoid the back flow of absolute ethanol. One patient had the particular complication of hydronephrosis caused by the incidental injection of absolute ethanol into the ureteral artery.
    Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 05/1993; 53(4):369-74.
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    ABSTRACT: A clinical trial of whole liver simultaneous dynamic MRI was done. In 23 second whole liver was able to be scanned using parameters of filed echo method as follows: TR = 315 msec, TE = 7 msec, Flip angle = 70 degrees or 90 degrees, MAT = 50%, ECD = 60%, FOV 40 cm and no presaturation. Even 2-3 mm nodules of metastatic tumors and small daughter nodules of hepatocellular carcinoma such as 5 mm were demonstrated in the arterial phase clearly.
    Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 06/1992; 52(5):674-6.
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    ABSTRACT: A new method was developed to display MR angiographic images. Nine MR angiographic images rotated along the cranio-caudal axis with ten incremental degree were constructed. These images were printed from left-anterior-oblique view to give a stereoscopic effect. With the stereoscopic viewing of these images, multiple stereoscopic images with different viewing directions were observed at once. Anatomical relationships of the vessels were more clearly understood than usual stereoscopic viewing. This multi-directional stereo viewing method is useful to display not only the MR angiographic images but also other multi-viewing techniques.
    Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 03/1992; 52(2):229-31.
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    ABSTRACT: Magnetic Resonance Angiography using a time-of-flight method was performed on two cases with arterial-portal shunting (A-P shunt). Each case was examined both with and without presaturation applied above the diaphragms. Signal intensity in the portal vein on these cases decreased with presaturation. This presaturation normally eliminates signal from inflowing spins in the artery but never effect on that in portal vein. Therefore the decrease of signal intensity in the portal vein with presaturation indicates the arterial inflow to the portal vein.
    Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 03/1991; 51(2):185-7.
  • M. Kato · K. Kawazoe · O. Sato
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    ABSTRACT: Applications of radioisotopes as tracers for flow measurements of rivers ; are discussed. Results are reported from field experiments using about 1 c of I/; sup 131/ or about 0.4 c of Na²⁴ as tracers. Direct measurements were made ; under water and samples were collected periodically downstream. Data on ; concentration versus time of flow were plotted. The maximum distance traced by ; 60 mc of Na²⁴ was about 30 kilometers. (C.H.);
    01/1962; 11(1). DOI:10.3769/radioisotopes.11.23
  • M. Kato · K. Kawazoe · O. Sato · Y. Takeuchi
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    ABSTRACT: Problems in chemical separation and measurement of radiotracer I¹³¹; and Br⁸² in flowing water were studied. The following procedure is ; recommended: (1) precipitation and filtration as Ag salt under acid conditions by ; adding conc. HâSOâ, carrier solution (NaI and NHâBr), and AgNO/; sub 3/; (2) addition of acetone to gather adhered Ag salt from the funnel and dry ; it; (3) solution of the precipitate in NaâSâ Oâ solution with ; NHâOH added; (4) gamma counting by a scintillation counter. The yield of ; radiotracer averaged 95%. The procedure is applicable to concentrations of 0.02 ; to 100 mu C/m³ of water. Water samples with higher activity are measured ; directiy by either BETA or gamma counting. (A.G.W.);