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A clinical study on the use of porous gelatin particles(sterile gelatin embolization material, YM 670, Gelpart) in transcatheter arterial embolization (TAE) was performed in patients with hepatocellular carcinoma, and the efficacy (embolization,anti-tumor effect, recanalization and operationality) and safety (tolerability) were studied. An additive agent comprising porous gelatin particles and low osmolarity contrast media was administered peripherally through a catheter into the hepatic artery proper of 63 patients with hepatocellular carcinoma. Good hepatic arterial embolization was confirmed in all cases (embolization: 100%), and a tumor necrosis effect was obtained in most cases (35/62 patients, 56.5%). Moreover, operationality was assessed as "highly easy to use" or "easy to use" in all cases. Frequencies of adverse events in which a relationship to TAE was not excluded and abnormalities of clinical laboratory data were high at 71.4% and 9 8.4%, respectively. The most common adverse reactions were pyrexia, abdominal pain, queasiness and blood pressure increase;abnormalities in clinical laboratory data included hepatic function with increased AST (GOT), increased ALT (GPT), decreased cholinesterase, increased LDH and increased total bilirubin. These adverse reactions and abnormalities in clinical laboratory data, however, were transient and attributed to the TAE procedure itself, and no adverse reactions related to YM 670 as an embolic material were observed. In addition, with regard to tolerability (safety), the treatment was assessed as suitable for use in all the present cases.

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BACKGROUND/AIMS: The objective of this study was to clarify the influence of radiofrequency ablation on the portal and hepatic vein. METHODOLOGY: Hepatic radiofrequency ablation was performed on 18 swine (mean weight, 22 kg). The livers were removed immediately, 1 week or 3 weeks following ablation. Vessel patency and diameter were determined by computed tomography, and the severity of endothelial injuries was determined histopathologically. RESULTS: The patency rate for portal and hepatic veins with diameters less than 3.0 mm decreased sequentially. At three weeks following ablation, the patency rate for vessels with diameters more than 3.0 mm was significantly higher (P<0.05) compared to those with diameters less than 2.0 mm. In portal and hepatic veins contiguous to ablated hepatic parenchyma, the endothelium with intimal thickening was found at 1 to 3 weeks following ablation, although its detection rate was decreased until 3 weeks. CONCLUSIONS: The portal and hepatic vein with diameters more than 3.0 mm in radiofrequency lesions maintained high patency. The endothelium seems to play an important role for maintaining vessels patency and the distal hepatic tissue following ablation. We believe that this maintained vascular patency may be the advantage of radiofrequency ablation over the PEIT.

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OBJECTIVE: Our aim was to evaluate the long-term clinical results after balloon-occluded retrograde transvenous obliteration (B-RTO) for gastric varices with spontaneous gastrorenal shunt. MATERIALS AND METHODS: A total of 78 patients with cirrhosis and with gastric varices, successfully treated by B-RTO, were enrolled in this study. Recurrence and bleeding of gastric varices and worsening of esophageal varices were endoscopically evaluated. Univariate and multivariate analyses were used to assess the prognostic factors for worsening of esophageal varices and survival. RESULTS: Recurrence of gastric varices was found in two patients; the 5-year recurrence rate was 2.7%. Bleeding of gastric varices occurred in only one patient after B-RTO; the 5-year bleeding rate was 1.5%. Worsening of esophageal varices was observed in 29 patients, and the worsening rates at 1, 3, and 5 years were 27%, 58%, and 66%, respectively. These esophageal varices were endoscopically treated to prevent rupture. Multivariate analysis showed the presence of esophageal varices before B-RTO was a prognostic factor for worsening (relative risk, 4.956). At a median follow-up of 700 days (range, 137-2,339 days), the survival rates at 1, 3, and 5 years were 93%, 76%, and 54%, respectively. The prognostic factors associated with survival were presence of hepatocellular carcinoma (relative risk, 24.342) and the Child-Pugh classification (relative risk, 5.780). CONCLUSION: B-RTO is an effective method for gastric varices with gastrorenal shunt and provides lower recurrence and bleeding rates. We believe that B-RTO can become a standard treatment for gastric varices with gastrorenal shunt, although treatment of worsened esophageal varices may be necessary after B-RTO.

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A 66-year-old woman with a gastric varix, draining into a dilated left adrenal vein and a left inferior phrenic vein, was treated with dual balloon-occluded retrograde transvenous obliteration (B-RTO). Under balloon occlusion of the left adrenal vein and the left inferior phrenic vein, retrograde injection of a sclerosant (5% ethanolamine oleate) into the gastric varix was performed. Two weeks later, disappearance of flow in the gastric varix was confirmed on endoscopic ultrasound examination.

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OBJECTIVE: The purpose of our study was to compare the efficacy and long-term results of transjugular intrahepatic portosystemic shunt (TIPS) with those of transcatheter sclerotherapy for the treatment of gastric varices. MATERIALS AND METHODS: A total of 139 cirrhotic patients with gastric varices underwent endovascular treatment. Of the 139 patients, 104 without hepatocellular carcinoma were enrolled; 27 patients were treated with TIPS, and 77 patients with transcatheter sclerotherapy. Bleeding of gastric varices and survival rates were compared between the TIPS and transcatheter sclerotherapy groups. Multivariate analysis was used to identify the prognostic factors for gastric variceal bleeding and survival. Changes in liver function were evaluated in each group. RESULTS: The cumulative gastric variceal bleeding rate at 1 year was 20% in the TIPS group and 2% in the transcatheter sclerotherapy group (p < 0.01). The prognostic factor associated with gastric variceal bleeding was the treatment method. The cumulative survival rates at 1, 3, and 5 years were, respectively, 81%, 64%, and 40% in the TIPS group and 96%, 83%, and 76% in the transcatheter sclerotherapy group (p < 0.01). The prognostic factors for survival were the treatment method and the Child-Pugh classification of liver disease. For patients categorized in Child-Pugh class A, the survival rate was higher in the transcatheter sclerotherapy group than in the TIPS group (p < 0.01). For patients in Child-Pugh classes B and C, no significant difference was seen between the two groups. Liver function tended to improve in the transcatheter sclerotherapy group. CONCLUSION: Transcatheter sclerotherapy may provide better control of gastric variceal bleeding than TIPS. Transcatheter sclerotherapy may contribute to a higher survival rate than TIPS in patients with Child-Pugh class A disease.

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OBJECTIVE: The performance of microPET using 18F-FDG was evaluated in a rabbit model of hematogenous pulmonary metastatic cancer. METHODS: A total of 15 Japanese white rabbits and VX-2 carcinoma were used in this study. In the microPET study, tumor-bearing rabbits were administered intravenously 74 MBq of 18F-FDG, and 30 min later, the emission data were acquired for 60 min. The transmission scans were performed with a 68Ge/68Ga external point source. To augment the anatomical information, we performed multi-detector row computed tomography (MDCT) in the combination with MDCT and microPET on 10 rabbits. The other 5 rabbits were followed once a week for 5 weeks only by microPET. Tumor/muscle (T/M) ratios were used for quantitative evaluation in this study. RESULTS: Multiple pulmonary nodules were detected by MDCT and microPET starting 14 days after the tumor injection. The high-uptake lesions in the lung detected by microPET corresponded well to the tumors detected by MDCT. The smallest nodule detected by microPET was ca. 1.5 mm in diameter. Overall, 87 nodules were detected by MDCT and the ratios of lesions detected by microPET to those by MDCT were 35.3%, 77.5%, and 90% for tumors equal to or smaller than 2 mm, 2-4 mm, and 4-6 mm in diameter, respectively. The respective T/M ratios were 2.41 +/- 0.41, 2.93 +/- 0.55, and 3.34 +/- 0.71. The T/M ratio increased with tumor size, but it was similar in each tumor size category. In the 35-day follow-up protocol, it was possible to follow sequentially the same tumor by the microPET. CONCLUSIONS: By FDG-microPET, it is possible to evaluate tumors larger than 2 mm in diameter and to follow the growth of individual tumors. Our results also suggest that the rabbit model of VX-2 pulmonary metastasis is a stable experimental model for evaluation using FDG. Monitoring of the therapeutic effects of anticancer drugs and radiation therapy could be tried by using this model and microPET.

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UNLABELLED: The purpose of this study was to evaluate PET using (18)F-FDG for gynecologic lesions with continuous bladder irrigation to eliminate artifacts from the (18)F-FDG activity in the bladder. METHODS: Forty-one patients were studied. They had 23 cervical uterine lesions (15 cases of cancer, 5 recurrences, 3 nonrecurrences); 8 cases of uterine corpus cancer, including 2 recurrences; and 10 ovarian masses (6 malignant, 4 nonmalignant). All cases of cancer were histologically proven; however, 2 cases of nonrecurrent uterine cervical carcinomas were diagnosed by clinical course. Continuous bladder irrigation was performed 35-55 min after intravenous administration of 185-370 MBq (18)F-FDG, and an emission scan was obtained 40-55 min after intravenous administration. Standardized uptake value (SUV) was used to estimate the degree of (18)F-FDG uptake quantitatively. RESULTS: After bladder irrigation, the (18)F-FDG activity in the urinary tract was eliminated in 33 patients, so that detection of tumor (18)F-FDG accumulation was easy. Two patients showed residual activity in the urinary bladder, and 6 patients showed activity in the ureter. An artifact was seen in 1 patient with residual activity in the urinary bladder caused by insufficient irrigation. However, these residual activities had no influence on detecting (18)F-FDG accumulation in tumor. The mean (+/-SD) of SUVs of malignant lesions was 6.04 +/- 3.22, that of nonmalignant lesions was 1.71 +/- 1.12, and the difference was significant (P = 0.0002). SUVs of all malignant lesions were greater than 2.0, and SUVs of all nonmalignant lesions, except the 1 case of ovarian fibroma, were less than 2.0. CONCLUSION: (18)F-FDG PET with continuous bladder irrigation is useful for eliminating (18)F-FDG activity in the bladder and for differentiating between malignant and nonmalignant uterine or ovarian masses.

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PURPOSE: To evaluate the potential effect of heat stress in inhibiting neointimal hyperplasia after angioplasty in an experimental model. MATERIALS AND METHODS: In vitro, proliferation and migration of heat-stress-induced and noninduced cells were compared with use of an endothelial cell/smooth muscle cell coculture model (five culture dishes in each experiment). Mild heat stress was induced via exposure of cultures to a temperature of 42 degrees C for 2 hours. In vivo, the neointimal thickness of ear arteries of Japanese white rabbits 7 days after denudation of endothelium was histologically evaluated in the control and heat-stress-induced groups (three rabbits in each group). RESULTS: Proliferation of heat-stress-induced smooth muscle cells declined significantly compared with that of noninduced cells in single-culture and coculture models. The migration rates of neither endothelial cells nor smooth muscle cells were significantly affected by heat stress. In vivo, the mean neointimal thickness was 13.8 micro m +/- 8.0 in the control group and 3.9 micro m +/- 2.1 in the induced group (P <.05). CONCLUSION: Induction of mild heat stress has great potential to reduce neointimal hyperplasia after angioplasty because it inhibits smooth muscle cell proliferation without inhibiting endothelial migration in vitro and suppresses neointimal growth in vivo.

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BACKGROUND/AIMS: Power Doppler ultrasonography can evaluate the hemodynamics of intrahepatic tumors. The ability of power Doppler ultrasonography to detect small hepatocellular carcinomas and estimate the differentiation of the tumor by the patterns of intranodular waves was assessed. METHODS: We used conventional B-mode ultrasonography, power Doppler ultrasonography, and dynamic computed tomography to examine 71 hepatocellular carcinomas (

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In liver cirrhosis, increased resistance of intrahepatic microvasculature contribute to the development of portal hypertension. This study aimed to reveal the alterations to hemodynamics in microvasculature of thioacetamide-induced fibrotic and cirrhotic rat livers, using in vivo microscopy. In fibrotic livers, although intrahepatic blood flow remained unaltered, area percentage of sinusoids was significantly decreased. In cirrhotic livers, intrahepatic blood flow was significantly increased concurrently with decrease in area percentage of sinusoids. The flow velocity and volume flow were significantly increased in terminal portal venules (TPVs) without changes in vascular diameters, whereas all these parameters were not altered in terminal hepatic venules (THVs). Intrahepatic shunts which emerged from TPVs and ran toward THVs, and anastomoses between neighboring THVs were formed in cirrhotic livers. These data indicate that the first occurring alteration of microcirculation in liver cirrhosis is decrease in sinusoidal beds.

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The aim of this study was to evaluate the efficacy of brachytherapy for preventing neointimal hyperplasia in the inferior vena cava (IVC) after stent placement. Sixteen beagles underwent Z-stent placement in the IVC and the aorta. For 8 of 16 beagles, irradiation (15 Gy) was delivered endoluminally to the stented segments of each vessel immediately after stent placement using the 192Ir. All animals were sacrificed after 6 weeks for morphometric and histopathologic examination. Morphometrically, neointimal thickness in the IVC of the radiation group was significantly decreased compared with the control group as well as that in the aorta (p < 0.05). Histopathologic findings showed the neointima in the IVC of the control group contained markedly organization of thrombus and neovascularization though that in the IVC of the radiation group consisted mainly of smooth muscle cells without organization of thrombus and neovascularization. From these data intravenous irradiation may prevent clinical restenosis after stent placement.

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The aim of this clinical study was to compare the image quality of digital radiography using the new digital Bucky system based on a flat-panel detector with that of a conventional screen-film system for the skeletal structure and the abdomen. Fifty patients were examined using digital radiography with a flat-panel detector and screen-film systems, 25 for the skeletal structures and 25 for the abdomen. Six radiologists judged each paired image acquired under the same exposure parameters concerning three observation items for the bone and six items for the abdomen. Digital radiographic images for the bone were evaluated to be similar to screen-film images at the mean of 42.2%, to be superior at 50.2%, and to be inferior at 7.6%. Digital radiographic images for the abdomen were judged to be similar to screen-film images at the mean of 43.4%, superior at 52.4%, and inferior at 4.2%; thus, digital radiographic images were estimated to be either similar as or superior to screen-film images at over 92% for the bone and abdomen. On the statistical analysis, digital radiographic images were also judged to be preferred significantly in the most items for the bone and abdomen. In conclusion, the image quality of digital radiography with a flat-panel detector was superior to that of a screen-film system under the same exposure parameters, suggesting that dose reduction is possible with digital radiography.

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UNLABELLED: Liver tumors, especially hepatocellular carcinomas (HCCs), often exhibit no contrast with surrounding non-tumorous liver tissue in F-18-fluoro-2-deoxy-2-fluoro-D-glucose (FDG) positron emission tomography (PET) images obtained at the usual interval of one hour after intravenous FDG injection. We evaluated the usefulness of FDG PET studies of liver tumors performed 2 hours after intravenous injection. METHODS AND MATERIALS: Fifteen pretherapeutic patients with 33 liver tumors were studied, including 11 patients with 18 HCCs, and 4 patients with 15 metastatic liver tumors (METAs) from 3 colorectal carcinomas and 1 esophageal carcinoma. After transmission scans, emission scans were obtained 45-55 minutes and 115-125 minutes after intravenous injection of 185-370 MBq FDG as early images and delayed FDG PET images, respectively. Visual analysis of early and delayed images was performed, and the FDG uptake in the tumor to that in nontumorous liver ratio (T/N ratio), the FDG uptake in tumor to that in soft-tissue ratio (T/S ratio) and the FDG uptake in non-tumorous liver to that in soft-tissue ratio (N/S ratio) were calculated for each image. RESULTS: In visual analysis, visual improvement seen in images was observed in 6 of 18 HCC lesions and all 15 META lesions. In quantitative analysis, the mean T/S ratio and T/N ratio of HCCs in early images were 4.97 and 1.90, respectively, and those in delayed images were 6.24 and 2.20, respectively. The mean T/S ratio and T/N ratio of METAs in early images were 5.97 and 2.21, respectively, and those in delayed images were 6.99 and 3.80, respectively. The T/S ratio of HCCs and T/S ratio and T/N ratio of METAs were significantly higher in delayed images than in early images. The mean N/S ratios of HCC cases were 2.58 in the early images and 2.57 in the delayed images, but the ratio showed no constant tendency in the images. All N/S ratios of META cases were decreased in delayed images, although the significance of the difference between early and delayed images in N/S ratios was not analyzed because of the small number of cases. CONCLUSION: FDG PET studies performed 2 hours after intravenous injection were useful for clear visualization of liver tumors, especially metastatic liver tumors.

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BACKGROUND/AIMS: To evaluate the hepatic microcirculatory changes in liver cirrhosis, in vivo microscopic findings were assessed quantitatively in cirrhotic rats. METHODOLOGY: Using in vivo microscopy, the blood flow velocity through terminal portal venules and terminal hepatic venules, and their diameters were measured. The rats were classified into a normal group, fibrosis group, and cirrhosis group, histopathologically. To estimate intrahepatic blood flow of the liver surface, laser-Doppler flowmeter was used for the three groups, and portal venous pressures were measured. RESULTS: Blood flow velocity through terminal portal venules increased significantly in cirrhosis rats. However, among the three groups, there were no significant differences with blood flow velocity through terminal portal venules, diameters of terminal portal venules and terminal hepatic venules. Portal venous pressure and intrahepatic blood flow of the liver surface increased significantly. CONCLUSIONS: These data indicate that pre-sinusoidal alterations to hemodynamics become manifest in the liver cirrhosis, which might be related to intrahepatic shunt formation.

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BACKGROUND/AIMS: The present study was conducted to accurately monitor the pattern of ethanol distribution during percutaneous ethanol injection by computed tomography fluoroscopy and to examine the relationship between the distribution pattern and therapeutic effect. METHODOLOGY: Twenty-five hypervascular hepatocellular carcinomas were studied. Each was treated with transcatheter arterial embolization. However, as residual parts were detected, percutaneous ethanol injection under real-time computed tomography fluoroscopy was performed. For analysis, ethanol distribution and local recurrence rate were compared. RESULTS: Ethanol distribution in a tumor was classifiable into 3 patterns. In pattern 1, ethanol solution was distributed spherically. In pattern 2, ethanol solution spread forming linear boundaries indicating interruption of distribution by septa. In pattern 3, ethanol spread circumferentially only along the periphery sparing the central part of a tumor. The 6-month recurrence rate of the tumors in which ethanol solution was distributed to the whole viable part was 25% (pattern 1), 100% (pattern 2) and 0% (pattern 3), respectively. CONCLUSIONS: In the tumors showing distribution pattern 3 by computed tomography fluoroscopy, a combination therapy of transcatheter arterial embolization and percutaneous ethanol injection was more effective than in other patterns. Computed tomography fluoroscopy was useful for accurate monitoring and predicting the therapeutic effect of percutaneous ethanol injection.

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Radiofrequency ablation (RFA) with a maximum output of < or = 70 W was used under CT guidance to treat 14 tumors (median diameter 1.5 cm, range 0.8 to 2.4 cm) in 6 patients. Primary lung cancer was treated in 2 patients, and metastatic lung tumors were treated in 4 patients. Good response was confirmed in 6 tumors on CT images, in one tumor on PET images, and in 2 tumors by histologic examination. In the other 5 tumors, curative effect was not determined because consolidation shadows surrounded the tumors. Complications were mild (pneumothoraces, 5; sputum cruentum, 4; subcutaneous emphysema, 3) except for one case of pleurisy. RFA of pulmonary malignancies appears to be a safe, effective treatment if a low output of less than 70 W is applied.

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