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Biomedical subjects

Osamu Matsui

Publications and source records attributed to Osamu Matsui.

At least 37 records · Page 2Linked to original sources
PubMed2005

Distal embolus protection with an intra-aortic filter during stent-graft repair of a severely atherosclerotic thoracic aortic aneurysm.

PURPOSE: To assess the technical feasibility and efficacy of distal embolus protection with an intra-aortic filter during stent-graft repair in a patient diagnosed with a shaggy aorta. TECHNIQUE: In a 75-year-old man with a severely atherosclerotic thoracic aortic aneurysm, stent-graft repair was combined with transposition of the arch branches to the ascending aorta under thoracotomy. A filtration-type embolus protection device with a nitinol basket and polyester fabric was introduced through a 12-F sheath and opened in the supraceliac aorta during the stent-graft procedure; it was safely pulled back into the sheath after the stent-grafts were implanted. The stent-graft repair was successful, and abundant atheromatous debris was captured in the filter. Neither procedure-related embolic events nor neurological deficits were observed. CONCLUSIONS: Use of the intra-aortic filter device to prevent distal embolism during thoracic stent-graft repairs may be feasible and efficacious in severely atherosclerotic patients.

Aged↗
PubMed2005

Phlebosclerotic colitis: imaging-pathologic correlation.

OBJECTIVE: The objective of this study was to analyze the imaging findings of phlebosclerotic colitis in comparison with histologic findings. CONCLUSION: Calcifications and/or obstructions of the veins of the colonic wall and adjacent mesentery and collateral formation, edematous thickening of the colonic wall, and increased density in the fatty tissue of the surrounding mesentery were features of this rare entity. However, in the early stage of the disease, no definite calcification of the affected veins was observed.

Aged↗
PubMed2005

MR findings of nine cases of palatal tumor.

PURPOSE: To assess the magnetic resonance imaging (MRI) findings of pathologically confirmed palatal tumors. METHODS: Nine cases of palatal tumor were studied. Clinical data, MRI findings, and pathological diagnoses were evaluated. RESULTS: Five cases were tumors of the hard palate and four of the soft palate. Signal intensity on T1-weighted images varied, and hyperintensity was observed on T2-weighted images. Adenoid cystic carcinoma and diffuse large B cell lymphoma showed homogenous signal intensity. Other tumors showed heterogeneous signal intensities. On dynamic contrast analysis, malignant pleomorphic adenoma, adenoid cystic carcinoma, diffuse large B cell lymphoma, and peripheral T cell lymphoma showed early enhancement. On post-contrast T1-weighted images, hard palate pleomorphic adenoma, malignant pleomorphic adenoma, adenoid cystic carcinoma, diffuse large B cell lymphoma, and peripheral T cell lymphoma showed strong enhancement. Although the borders of the tumors were classified as clear in 6 cases treated surgically, macroscopic and microscopic borders of the tumors were unclear. Adenoid cystic carcinoma and hard palate diffuse large B cell lymphoma invaded the maxillary bone. CONCLUSION: Magnetic resonance findings of palatal tumor varied in different histologies. Even with a small palpable portion, malignant tumors could directly infiltrate surrounding structures, which demonstrated well on MRI.

Adenoma, Pleomorphic↗
PubMed2005

[Effect of saline flush using dual injector on abdominal dynamic contrast enhanced computed tomography].

PURPOSE: To evaluate the efficacy of the saline flush technique for abdominal multidetector-row computed tomography (CT). METHODS: As a clinical study, 147 patients with chronic hepatic disease were divided into two groups: group A, given 100 cc of contrast material flushed with 50 cc of saline; and group B, given 100 cc of contrast material only. The difference in attenuation values between groups A and B, and cirrhotic liver and non-cirrhotic liver were evaluated. As an in-vitro experimental study, time vs. peak pressure curve was obtained changing injection devices. RESULTS: Group B showed a greater contrast enhancement effect in the early arterial equilibrium phase of the aorta and late arterial phase of the liver. In cirrhotic liver, the aorta showed greater contrast enhancement in the early arterial phase in group A. Attenuation values of hypervascular hepatic nodules showed no statistically significant difference between groups A and B. Time to reach peak pressure was prolonged when using saline flush devices in vitro. Flow of contrast material from the contrast material cylinder to the saline cylinder was also discovered. CONCLUSION: Saline flush causes peak arterial contrast to be strong for a short duration. Abdominal organ attenuation values are not necessarily increased in the saline flush method. It is important to know that contrast enhancement is dependent on the injection device.

Aorta, Abdominal↗
PubMed2005

Kasabach-Merritt syndrome associated with giant liver hemangioma: the effect of combined therapy with danaparoid sodium and tranexamic acid.

n patients with Kasabach-Merritt syndrome (KMS), local activation of coagulation commonly results in disseminated intravascular coagulation (DIC). Progress of DIC is associated with 30-40% mortality as a result of uncontrollable hemorrhage. A 39-year-old woman with an enlarging giant liver hemangioma was diagnosed as having KMS with DIC. To control the hemorrhagic diathesis, we commenced combination therapy for DIC with danaparoid (1,250 Ux2/day, intravenously (IV)) and tranexamic acid (0.5 g x 3/day, peros (PO). Rapid improvement of the bleeding tendency and coagulopathy occurred in response to this treatment - that is, DIC was controlled without removing the giant hemangioma. The therapy did not restrict the behavior of the patient by continuous drip and angiography could be performed without bleeding. Such therapy may be beneficial in chronic DIC with activation of fibrinolysis.

Adult↗
PubMed2005

CT and MRI findings of carcinoma showing thymus-like differentiation.

Carcinoma showing thymus-like differentiation (CASTLE) is a rare tumor that occurs in the soft tissue of the neck or in the thyroid gland. We report a case of CASTLE in a 54-year-old man presenting with hoarseness. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a mass enclosing the right carotid artery with the shape of lobulation and invasion to the trachea. The mass was hypointense on T1-weighted imaging and, on T2-weighted imaging, showed a hyperintense periphery with isointense center relative to muscle. In dynamic MRI, the mass revealed gradual but slight heterogeneous enhancement from the periphery. Diagnosis was confirmed by histopathology.

Carcinoma↗
PubMed2004

Collaterals through hepatic sinusoids after embolization of terminal portal venules: an in vivo study on mice.

The changes of intrahepatic microcirculation during the very early stage of portal venule obstruction are not well known. The aim of this study was to clarify the immediate alterations of intrahepatic microcirculation after selective obstruction of the terminal portal venules in vivo. After selective embolization of terminal portal venules with plastic beads whose diameter was 30-35mum, the hepatic microcirculation of 136 embolized areas on 15mice was observed with epi-illuminated in vivo fluorescent microscopy. There was reverse blood flow in sinusoids resulting in three types of collaterals after embolization of the terminal portal venules. These collaterals were derived from the proximal trunk of the embolized terminal portal venules, adjacent branches and neighboring terminal portal venules, and they could appear simultaneously with a frequency of 59/136 (43.4%), 77/136 (56.6%) and 131/136 (96.3%), respectively. Collateral formation was strongly correlated with the state of blood flow in the surrounding area (P<0.0001), but not with the extent of the embolized areas. The results indicated that after embolization of terminal portal venules, reverse blood flow occurred in sinusoids to form collaterals, and these collaterals could maintain the microcirculation of the embolized area.

Journal Article↗
PubMed2004

Combined use of an occlusion balloon catheter and a microcatheter for embolization of the unselectable right inferior phrenic artery supplying hepatocellular carcinoma.

We report the combined use of an occlusion balloon catheter and a microcatheter for transcatheter arterial embolization (TAE) of hepatocellular carcinoma (HCC) fed by the unselectable right inferior phrenic artery (IPA). In one case, HCC was fed by the reconstructed right IPA via a small branch arising from the proximate portion of the celiac artery. In another, the tumor was fed by the right IPA that had been previously embolized with coils. TAE was successfully performed through a microcatheter placed in the celiac artery immediately proximal to the occluding balloon catheter of the celiac trunk and coil embolization of the left gastric artery.

Aged↗
PubMed2004

Efficacy of covered metallic stents in the treatment of unresectable malignant biliary obstruction.

We evaluated the efficacy of covered stents for malignant biliary obstruction. We studied 62 patients with obstruction distal to the hilar confluence who survived longer than 10 weeks and divided them into a covered stent group (group 1, n = 22), a Z stent group (group 2, n = 19), and a mesh stent group (group 3, n = 21), according to their type of the stent. Patency rates of each group were compared. Early stent revision was required after 3 days in 18% (4/22) of group 1, 26% (5/19) of group 2, and 0% (0/21) of group 3. The 10, 20, and 40-week primary patency rates were 77%, 77%, and 59% (group 1), 42%, 25%, and 8% (group 2), and 76%, 71%, and 55% (group 3), respectively. Primary patency rates of groups 1 and 3 were significantly higher than those of group 2 (p < 0.05), and there was no statistically difference between those of group 1 and group 3. The 10, 20, and 40-week assisted primary (secondary) patency rates were 96%, 96%, and 96% (group 1), 68%, 49%, and 39% (group 2), and 86%, 74%, and 58% (group 3), respectively. Assisted primary patency (secondary) rates of group 1 were significantly higher than those of groups 2 and 3 (p < 0.01 and p < 0.05, respectively). Our study suggests that the primary patency rates of the covered stents are equal to those of mesh stents, but these may be improved further if covered stents, which avoid the need for early revision, are used.

Adult↗
PubMed2004

Transcatheter arterial chemoembolization for hepatocellular carcinoma fed by the reconstructed inferior phrenic artery: anatomical and technical analysis.

PURPOSE: To evaluate reconstructed patterns of occluded inferior phrenic artery (IPA) and determine the technical success rate and complications of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) fed by the occluded IPA through the anastomosing branch. MATERIALS AND METHODS: In 19 patients, 24 IPAs, including two that had been previously embolized, were demonstrated through collateral pathways. The incidence of each collateral circulation was evaluated. Thirteen IPAs in 12 patients fed the tumor and TACE was attempted. TACE was performed only if the catheter could be advanced into the anastomosing branch so that the nontarget branches were avoided. RESULTS: A reconstructed unilateral IPA was observed in 14 patients (11 right IPAs and three left IPAs) and two reconstructed IPAs were observed in five. The IPA was demonstrated through the dorsal pancreatic artery (n = 13), inferior or middle adrenal artery (n = 7), left gastric artery (n = 2), contralateral IPA (n = 2), lumbar artery (n = 1), and small branch derived from the celiac trunk (n = 1). Five IPAs (21%) were demonstrated through more than two separate arteries, including two demonstrated through both dorsal pancreatic arteries arising from the celiac and superior mesenteric artery. The IPA opacified through the lumbar artery had been previously embolized. TACE of the reconstructed IPA was possible in 10 of 13 IPAs (77%). Complications related to the procedure were a small amount of pleural effusion (n = 4) and basal atelectasis (n = 2). CONCLUSION: The IPA is reconstructed mainly through the retroperitoneal anastomosing branch in the upper abdomen. TACE of the reconstructed IPA can be performed with a high success rate without major complications.

Adrenal Glands↗
PubMed2004

Critical role for chicken Rad17 and Rad9 in the cellular response to DNA damage and stalled DNA replication.

The Rad17-replication factor C (Rad17-RFC) and Rad9-Rad1-Hus1 complexes are thought to function in the early phase of cell-cycle checkpoint control as sensors for genome damage and genome replication errors. However, genetic analysis of the functions of these complexes in vertebrates is complicated by the lethality of these gene disruptions in embryonic mouse cells. We disrupted the Rad17 and Rad9 loci by gene targeting in the chicken B lymphocyte line DT40. Rad17-/- and Rad9-/- DT40 cells are viable, and are highly sensitive to UV irradiation, alkylating agents, and DNA replication inhibitors, such as hydroxyurea. We further found that Rad17-/- and Rad9-/- but not ATM-/- cells are defective in S-phase DNA damage checkpoint controls and in the cellular response to stalled DNA replication. These results indicate a critical role for chicken Rad17 and Rad9 in the cellular response to stalled DNA replication and DNA damage.

Amino Acid Sequence↗
PubMed2004

Imaging of multistep human hepatocarcinogenesis by CT during intra-arterial contrast injection.

Various types of hepatocellular nodules are seen in cirrhotic livers. In these nodules, two types of human hepatocarcinogenesis are now considered. One is de novo hepatocarcinogenesis and the other is the stepwise development from high-grade dysplastic nodule (DN), high-grade DN with well-differentiated HCC foci, and overt HCC. According to our analysis by CT during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) and histological study, in accordance with the elevation of the grade of malignancy of the nodules, the portal tract including normal portal vein (intranodular portal supply) and hepatic artery (intranodular arterial supply through normal hepatic arteries) are decreased. On the other hand, abnormal artery (intranodular arterial supply through newly formed abnormal arteries) gradually increases. Therefore, we can estimate the grade of malignacy of the nodules from intranodular blood supply. To know this blood supply pattern is important for the early detection, characterization and treatment of early stage HCCs. We also revealed that there was a close correlation between the prognosis of the nodules and the blood supply patterns.

Angiography↗
PubMed2004

[Online-conference using JGN.].

Telemedicine and online conference systems have some benefits so that equalizing medical level, improving efficiency of medical care and improving service for patients. It is possible to give advice and to support its medical projects stationed in other facility and to provide the same quality treatments for patients. In this paper, we set up an experimental network system to teleconference using JGN (Japan Gigabit Network) and tried to discussion alternatively for case study between Kanazawa university and Fukui red cross hospital, 70 km away. The JGN used in this study is an ultra-high-speed network for the purpose of research and development. Kanazawa university, and Fukui red cross hospital are connected by a 10 Mbps communication link of the JGN. We tried online conference on the experimental network using video chat system. In result, using video chat system, the average transmission rate of MRI images (256 X 256pixel, 16bit) is 0.2 s/frame.

Biomedical Research↗
PubMed2003

Percutaneous cholecystocholedochostomy for cholecystitis and cystic duct obstruction in gallbladder carcinoma.

Percutaneous cholecystocholedochostomy was performed in a patient with acute cholecystitis caused by cystic duct obstruction by gallbladder carcinoma, but removal of the percutaneous cholecystostomy catheter was unsuccessful because of continuing discharge. After creation of a cholecystocholedochostomy through the cholecystostomy tract with use of a transjugular liver access set and a 21-gauge needle, self-expandable metallic stents were placed in the narrowed common bile duct and the newly created tract between the gallbladder and the common hepatic duct. The external cholecystostomy catheter was successfully removed after the procedure. Jaundice occurred 70 days later as a result of tumor invasion above the segment with the stent, and an additional stent was placed. The patient died of diffuse metastasis 143 days after creation of the cholecystocholedochostomy without recurrence of cholecystitis.

Adenocarcinoma↗
PubMed2003

Transcatheter arterial chemoembolization for unresectable hepatocellular carcinoma fed by the cystic artery.

PURPOSE: To evaluate the safety, technical success rate, and effectiveness of transcatheter arterial chemoembolization (TACE) for unresectable hepatocellular carcinoma (HCC) fed by the cystic artery. MATERIALS AND METHODS: Treatment of 27 tumors in 25 patients fed by the cystic artery was attempted with TACE. Twenty-two patients had previously undergone one to eight TACE sessions (mean, four sessions), and the duration after initiation of treatment of HCC was 4-69 months (mean, 24). In three patients, parasitization of the cystic artery was revealed at initial angiography. TACE was performed only when the microcatheter could be inserted into the tumor feeding branch and the stain of the gallbladder wall disappeared. The therapeutic effects and complications were retrospectively analyzed. RESULTS: Seventeen tumors were completely fed by the cystic artery and 10 were fed by both the hepatic artery and cystic artery. Attenuation or occlusion of the hepatic artery was observed in 56%. The tumor feeding branch arising from the cystic artery could be successfully embolized in 18 tumors (67%) of 16 patients without severe complications. Adequate iodized oil accumulation was achieved in 14 tumors (52%) of 12 patients. Percutaneous therapy (n = 7), radiation (n = 4), and TACE after cholecystectomy (n = 1) were added for tumors with incomplete or unsuccessful TACE. Local progression was observed in three (21%) of 14 tumors treated by TACE alone during a mean follow-up period of 18 months. CONCLUSION: TACE via the cystic artery was safe and technically possible in 67% of patients. If adequate iodized oil accumulation is obtained, which was only achieved in 52% of patients, sufficient therapeutic effect may be expected.

Aged↗