Biomedical subjects

Junichiro Sanada

Publications and source records attributed to Junichiro Sanada.

16 recordsLinked to original sources

PubMed2005

Cirrhotic nodules: association between MR imaging signal intensity and intranodular blood supply.

PURPOSE: To retrospectively determine whether there is a relationship between the intranodular blood supply evaluated at computed tomography (CT) during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) and the magnetic resonance (MR) imaging signal intensity of nodules associated with cirrhosis. MATERIALS AND METHODS: Neither institutional review board approval nor informed consent was required for retrospective reviews of medical records and images. One hundred fourteen hepatocellular nodules 10 mm or greater in largest diameter in 58 patients (39 men, 19 women; mean age, 61 years) with cirrhosis were evaluated at CTAP, CTHA, and MR imaging. The CTAP and CTHA nodule findings were divided into three main types: Type A nodules were isoattenuating at CTAP and hypoattenuating at CTHA; type B nodules, slightly hypoattenuating at CTAP and hypoattenuating at CTHA; and type C nodules, strongly hypoattenuating at CTAP and hyperattenuating at CTHA. The relationships between the CTAP and CTHA findings and the MR imaging signal intensity among these nodules were analyzed by using the chi(2) test. RESULTS: On T1-weighted MR images, 27 (63%) of 43 type A nodules were hyperintense, nine (39%) of 23 type B nodules were isointense, and 19 (48%) of 40 type C nodules were hypointense; differences were not significant. On T2-weighted MR images, 31 (72%) of 43 type A nodules were hypointense (P < .05), 12 (52%) of 23 type B nodules were isointense, and 34 (85%) of 40 type C nodules were hyperintense (P < .05). CONCLUSION: There was a significant association between intranodular blood supply and nodule signal intensity on T2-weighted MR images. However, study findings did not show whether the blood itself (ie, blood volume or blood flow amount) directly influenced the signal intensity.

Adult↗

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↗

PubMed2003

Clinical application of a curved nitinol stent-graft for thoracic aortic aneurysms.

PURPOSE: To evaluate the clinical efficacy of a curved nitinol stent-graft for repair of thoracic aortic aneurysms. METHODS: The Matsui-Kitamura stent-graft (MKSG), composed of a self-expanding nitinol stent and polyester fabric, was shaped to match the aortic curvature of 11 patients (6 men; mean age 72.6 years, range 33-90) with 6 true and 5 false aneurysms of the distal arch or proximal descending aorta. The delivery system was an 18 or 20-F J-shaped sheath combined with a preloader-type introducer. The original mean proximal neck length was 16.4 mm, but 4 patients received an axilloaxillary bypass to lengthen the neck. Although the mean corrected proximal neck length was 21.9 mm (overall), 5 cases still had proximal necks <15 mm long. RESULTS: All curved MKSGs were successfully deployed in the correct position and fitted to the curvature of the aortic arch, achieving complete aneurysm exclusion in 8 (73%) cases. The other 3 repairs displayed early endoleaks; 1 received an additional MKSG, but the other 2 are being observed. Thirty-day mortality was 0%. One patient developed transient renal failure requiring hemodialysis; no neurological complications were observed. CONCLUSIONS: Endovascular repair of thoracic aortic aneurysms using curved MKSGs appears to be feasible and clinically effective. A tighter fit of the device to the curvature of the aortic arch may exclude distal arch aneurysms despite a short proximal neck.

Adult↗

PubMed2003

Stent-graft repair of a mycotic left subclavian artery pseudoaneurysm.

PURPOSE: To report successful stent-graft treatment of a mycotic pseudoaneurysm of the left subclavian artery in an immunosuppressed patient. CASE REPORT: A 17-year-old immunosuppressed woman undergoing treatment for recurrent leukemia developed persistent fever and 2 episodes of hemoptysis. A contrast-enhanced computed tomographic (CT) scan demonstrated a saccular aneurysm of the left subclavian artery, which was considered to be a mycotic aneurysm caused by erosive fungal infection from the lung. The pseudoaneurysm was treated with a homemade stent-graft consisting of a nitinol stent and a polyester fabric. A type II endoleak present at the end of the procedure appeared to have sealed spontaneously on the CT scan at 3 days. No neurological deficit or ischemic symptoms of the left arm were noted during the follow-up, which lasted until the patient died 11 months later after rejecting a second bone marrow transplant. CONCLUSIONS: Endovascular repair may be an alternative to open surgery for the management of mycotic aneurysms of the subclavian artery.

Adolescent↗

PubMed2003

Mediastinal bronchial artery aneurysm treated with a stent-graft.

PURPOSE: To report a rare case of mediastinal bronchial artery aneurysm successfully treated with an endovascular stent-graft. CASE REPORT: A 79-year-old man with a history of tuberculosis was admitted to our hospital complaining of worsening hoarseness. Examination revealed a large mediastinal bronchial artery aneurysm located near the origin of the artery. Since neither surgical intervention nor transcatheter embolization was feasible, an endovascular stent-graft repair was performed using a newly developed stent-graft constructed from a nitinol stent and a thin membrane of polyester. Postprocedural angiography showed satisfactory exclusion of the aneurysm. The patient made an uneventful recovery. The 18-month computed tomographic scan documented continued exclusion of the aneurysm, with no evidence of endoleak, graft thrombosis, or migration. CONCLUSIONS: When conventional procedures are too complicated for bronchial artery aneurysms, endovascular stent-graft repair can be a useful approach.

Aged↗

PubMed2002

Groove pancreatic carcinomas: radiological and pathological findings.

The aim of this study was to clarify the characteristics of pancreatic head carcinomas mainly invading the groove between the duodenum and the pancreatic head. Nine patients with pathologically proven pancreatic head carcinomas underwent thin-slice dynamic CT, MR imaging, duodenal endoscopy, and angiography (seven patients). Plate-like masses within the groove region were seen in all cases, which showed hypointensity on T1-weighted images and slight hyperintensity on T2-weighted MR images. The masses appeared hypovascular in the early phase and delayed enhancement in the late phase of dynamic CT and MR imaging. On MR cholangiopancreatography, stenosis of intrapancreatic common bile duct was seen in all patients, whereas stenosis of the main pancreatic duct was seen in only three cases. Endoscopy revealed luminal narrowing of the duodenum in all patients, and duodenal mucosal biopsy demonstrated adenocarcinoma in seven patients. Abdominal arteriography showed serrated encasement of peripancreatic arteries in seven patients who received angiographic examinations. The CT and MR imaging findings of groove pancreatic carcinomas resemble those of groove pancreatitis. Differential diagnosis may be achieved by the pathological diagnosis of a biopsy specimen of the duodenal mucosa and arterial encasement on arteriography.

Adenocarcinoma↗

PubMedDate not supplied

MR imaging of hepatocellular carcinomas with biliary tumor thrombi.

We retrospectively evaluate the MR imaging findings of hepatocellular carcinomas (HCC) with biliary tumor thrombi. MR imaging was performed on six patients presenting with obstructive jaundice and/or biliary hemorrhage. T1-weighted images, T2-weighted images, MR cholangiopancreatography (MRCP), and dynamic MR images were obtained. Duodenal endoscopy was performed on all cases and hepatic resection on two cases. HCCs were 1.8-10 cm in diameter (mean 5.8 cm). Biliary tumor thrombi were detected in all patients on MR imaging. Tumor thrombi showed hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and contrast enhancement on the early phase of dynamic MR images. MRCP showed intrahepatic bile duct dilatation in all cases. Biliary hemorrhage was clearly depicted by MR images in five cases and showed hyperintensity on T1-weighted images and hyperintensity or hypointensity on T2-weighted images. Biliary hemorrhage was confirmed by endoscopy in two cases. Portal vein thrombi were also associated in five of six patients. Pathologically, tumor thrombi of HCCs were demonstrated in two patients who underwent hepatic resection. In conclusion, MR imaging is useful for the diagnosis of biliary tumor thrombi from HCC and for evaluating the extension of thrombi and biliary hemorrhage.

Aged↗

PubMedDate not supplied

CO2 demonstration of multiple extravasations into a subcapsular hematoma of the liver.

In a case of esophageal cancer with liver metastases, rupture of a liver metastasis resulted in subcapsular hematoma of the liver. Digital subtraction angiography with carbon dioxide showed multiple extravasations at the surface of the liver suggesting multiple ruptures of the penetrating hepatic capsular arteries. It was suggested that these findings are not rare in cases of subcapsular hematoma; however, they have received little attention.

Angiography, Digital Subtraction↗

PubMedDate not supplied

Endovascular stent-grafting for infected iliac artery pseudoaneurysms.

We report two cases of acutely infected pseudoaneurysms of the iliac arteries, successfully treated with endovascular stent-grafting. Two patients underwent stent-graft treatment for erosive rupture of the iliac artery caused by surrounding infection. The first case is that of a 61-year-old man who had undergone Miles' operation for an advanced rectal cancer. Postoperatively, he developed intrapelvic abscess formation, from which methicillin-resistant Staphylococcus aureus was cultured, followed by rupture of the right external iliac artery. The second case is that of a 60-year-old man who had a pseudoaneurysm of the left common iliac artery, which was contiguous with a left psoas muscle abscess, from which Streptococcus agalactiae was cultured. Both patients were successfully treated with only a stent-graft and antibiotic therapy, and remained symptom-free 12 months and 10 months later. Although endovascular stent-grafting should not be considered standard therapy for infected aneurysms, our cases suggest that it can result in repair of infected aneurysms even in the uncontrolled active stage.

Aneurysm, False↗

PubMedDate not supplied

Usefulness of grasping a guiding catheter with a loop-snare wire for stent placement into the vertebrobasilar artery.

In cases in which the subclavian artery is severely tortuous or branches with an extremely angulated origin, stent placement in the vertebrobasilar artery on the approach from the femoral artery is often technically difficult. We report two cases in which a stent placement procedure for the vertebrobasilar artery was successfully performed by grasping a guiding catheter with a loop-snare wire. This technique is useful for tortuous arteries or arteries branching with an extremely angulated origin.

Aged↗

PubMedDate not supplied

Feeding artery of laryngeal and hypopharyngeal cancers: role of the superior thyroid artery in superselective intraarterial chemotherapy.

The purpose of this study was to elucidate the role of the superior thyroid artery in intra-arterial infusion chemotherapy for laryngeal and hypopharyngeal cancers. Thirty-nine patients with laryngeal cancer and 29 patients with hypopharyngeal cancer underwent intra-arterial infusion chemotherapy. We performed a retrospective analysis of the feeding arteries confirmed by computed tomography during selective arteriography and compared the results with the extent of the tumors. In 14 of 39 laryngeal and 15 of 29 hypopharyngeal cancers, the tumor did not cross the midline (group 1). In the remaining 25 and 14 cancers, respectively, the tumor crossed the midline or located in the center (group 2). For 13 of 14 laryngeal and 7 of 15 hypopharyngeal cancers in group 1 and for 6 of 25 laryngeal cancers in group 2, the entire tumor was contrast enhanced by the ipsilateral superior thyroid and/or superior laryngeal artery. For 12 of 25 laryngeal and 1 of 14 hypopharyngeal cancers in group 2, the entire tumor was contrast enhanced by the bilateral superior thyroid artery. For the other patients, infusion via the other arterial branches such as the inferior thyroid and the lingual arteries were needed to achieve contrast enhancement of the entire tumor. Superselective intra-arterial chemotherapy for laryngeal cancer from the superior thyroid artery is appropriate, whereas that for hypopharyngeal cancer is less sufficient. To accomplish contrast enhancement of the entire tumor, additional intra-arterial infusion from other arteries such as the inferior thyroid artery is often necessary.

Aged↗

PubMedDate not supplied

Bronchial artery aneurysm embolization with NBCA.

We present a case of asymptomatic bronchial artery aneurysm that formed a fistula with part of the pulmonary artery (there was no definite fistula with the pulmonary vein). We were able to catheterize the feeding vessel but could not reach the aneurysm. We therefore injected a mixture of N-butyl-2-cyanoacrylate (NBCA; Histoacryl, B. Braun, Melsungen, Germany) and iodized oil (Lipiodol; Guerbet, Aulnay-sous-Bois, France) from the feeding vessel. The fistula, aneurysm, and feeding vessel were almost totally occluded. After embolization, the patient coughed a little; there were no other definite side effects or complications. One and 3 months later, on chest CT, the aneurysm was almost completely occupied with hyperattenuating NBCA-Lipiodol embolization. NBCA is a liquid embolization material whose time to coagulation after injection can be controlled by diluting it with Lipiodol. It is therefore possible to embolize an aneurysm, feeding vessels, and efferent vessels (in our case, it was a fistula) by using an NBCA-Lipiodol mixture of an appropriate concentration, regardless of whether the catheter can reach the aneurysm or not.

Adult↗

PubMedDate not supplied

Spontaneous hemothorax in neurofibromatosis treated with percutaneous embolization.

We evaluated the effectiveness of transcatheter arterial coil embolization therapy for the treatment of spontaneous hemothorax followed by aneurysm rupture in neurofibromatosis patients. Three patients were treated for massive hemothorax caused by arterial lesions associated with neurofibromatosis. Bleeding episodes were secondary to ascending cervical artery aneurysm and dissection of vertebral artery in 1 patient, and intercostal artery aneurysm with or without arteriovenous fistula in 2 patients. Patients were treated by transarterial coil embolization combined with chest drainage. In 1 patient, the ruptured ascending cervical artery aneurysm was well embolized but, shortly after the embolization, fatal hemorrhage induced by dissection of the vertebral artery occurred and the patient died. In the other 2 patients, the ruptured intercostal artery aneurysm was well embolized and they were successfully treated and discharged. Transcatheter arterial coil embolization therapy is an effective method for the treatment of spontaneous hemothorax followed by aneurysm rupture in neurofibromatosis patients.

Adult↗

PubMedDate not supplied

Peritumoral rim enhancement of liver metastasis: hemodynamics observed on single-level dynamic CT during hepatic arteriography and histopathologic correlation.

PURPOSE: The purpose of this work was to clarify the mechanism of peritumoral rim enhancement of metastatic liver cancer. METHOD: Twenty-nine liver metastases of colon cancer were examined by single-level dynamic CT during hepatic arteriography, which was performed without table feed. We analyzed these findings and correlated them with the histopathologic findings. RESULTS: Eleven metastases were hypervascular and 18 were hypovascular. Early appearance of rim enhancement was seen in 3 of 10 hypervascular metastases and 17 of 18 hypovascular metastases (p < 0.01). The time of appearance and thickness of peritumoral rim enhancement showed no apparent correlation with the desmoplastic reaction or inflammation in the surrounding hepatic parenchyma. CONCLUSION: Two types of intra- and peritumoral enhancement were observed. Peritumoral rim enhancement was considered to be due mainly to the drainage of blood flow from the tumor to the surrounding hepatic parenchyma in hypervascular metastasis or increased arterioportal shunts surrounding the tumor in hypovascular metastasis.

Angiography↗

PubMedDate not supplied

An experimental study of a new pull-through technique for aortic arch aneurysm in a porcine model.

A new pull-through technique for placement of the aortic arch stent-graft was developed. Self-expandable curved stents (Matsui-Kitamura stents) were used on 4 pigs. With use of the endoscopic system, the sheath insertion was performed at the ascending aorta. By this pull-through method from the ascending aorta to the femoral artery, the stent was deployed into the aortic arch. All stents were successfully deployed into the correct position, and they fitted into the curvature of the aortic arch wall. By this method, stent-grafting for aortic arch aneurysm is expected to be performed with more accuracy and safety.

Animals↗

PubMedDate not supplied

Prevention of hepatic infarction as acute-phase complication of TIPS by temporary balloon occlusion in a patient with primary myelofibrosis.

Severe acute liver dysfunction occurred following transjugular intrahepatic portosystemic shunt (TIPS) creation in a patient with massive ascites due to portal hypertension associated with primary myelofibrosis. On US and TIPS venography, we considered that the acute liver ischemia was induced by TIPS. To avoid diffuse hepatic infarction and irreversible liver damage, a balloon catheter was inserted transjugularly into the TIPS tract and occluded it to increase portal venous flow toward the peripheral liver parenchyma. The laboratory data indicating hepatic dysfunction were improved after the procedure. We should pay attention to the possible occurrence of acute hepatic ischemia and infarction after TIPS creation even in a case of noncirrhotic portal hypertension. In such cases, temporary balloon occlusion of TIPS is an effective therapeutic method, probably as a result of inducing the development of arterial compensation through the peribiliary plexus.

Acute-Phase Reaction↗