Kaname Matsumura

Transcatheter arterial embolization of ruptured pseudoaneurysms with coils and n-butyl cyanoacrylate.

PURPOSE To evaluate the clinical efficacy of transcatheter arterial embolization with n-butyl cyanoacrylate (NBCA) for ruptured pseudoaneurysms, which are difficult to control by coil embolization alone. MATERIALS AND METHODS Ruptured pseudoaneurysms developed at the celiac trunk (n = 1), gastroduodenal artery (n = 2), pancreatic arcade (n = 1), hepatic artery (n = 3), renal artery (n = 1), and intercostal artery (n = 1) in nine patients. NBCA was mixed with iodized-oil (1:2) and injected via the 3-F microcatheter under fluoroscopic guidance, after the catheter was advanced close to the pseudoaneurysm. Coil embolization was performed to control blood flow before administration of NBCA in seven patients. NBCA was injected immediately after coil embolization in four patients. Embolization with NBCA was performed for recurrent bleeding that occurred within 1-21 days (mean, 10.7 days) after initial coil embolization in three patients. Two patients with peripheral pseudoaneurysms underwent embolization with NBCA alone. RESULTS The NBCA mixture was visible under fluoroscopy, and was useful in monitoring the embolization process and deciding the endpoint. Embolization was technically successful without major complications in all patients. Pseudoaneurysms and afferent and efferent arteries were eliminated immediately after embolization. Bleeding was stopped after embolization in all cases. Rebleeding did not occur in any patient during their follow-up periods of 0.7-69.5 months (mean, 17.9 months). CONCLUSION Embolization with NBCA is a feasible and useful treatment for ruptured pseudoaneurysms, which are difficult to control by coil embolization alone.

Superselective Bronchial Artery Embolization for Hemoptysis with a Coaxial Microcatheter System

PURPOSE To compare the effectiveness and safety of superselective bronchial artery embolization with that of nonsuperselective embolization in the control of hemoptysis. MATERIALS AND METHODS Retrospective case analysis was done for 47 patients with hemoptysis originating from a variety of causes. In 22 patients, embolization was performed superselectively using a microcatheter inserted into the bronchial artery beyond the spinal or mediastinal branches (superselective group). In the remaining 25 patients, embolization was performed at the opening of the bronchial artery with a 5-F catheter (nonsuperselective group). RESULTS Initial hemoptysis control rates were 96% (21 of 22) in the superselective group and 88% (22 of 25) in the nonsuperselective group. Cumulative hemoptysis control rates of the superselective and nonsuperselective groups were 80% and 67% at 6 months, 79% and 56% at 1 and 2 years, and 79% and 48% at 3 years, respectively (not significant; generalized Wilcoxon test). One major complication (spinal infarction) occurred in the nonsuperselective group. CONCLUSIONS Superselective embolization is safer and more effective way to control hemoptysis than the ordinary (nonsuperselective) method.

Pulmonary ventilation-perfusion MR imaging in clinical patients.

The purpose of this study was to evaluate the feasibility of comprehensive magnetic resonance (MR) assessment of pulmonary perfusion and ventilation in patients. Both oxygen‐enhanced ventilation MR images and first‐pass contrast‐enhanced perfusion MR images were obtained in 16 patients with lung diseases, including pulmonary embolism, lung malignancy, and bulla. Inversion recovery single‐shot fast spin‐echo images were acquired before and after inhalation of 100% oxygen. The overall success rate of perfusion MR imaging and oxygen‐enhanced MR imaging was 94% and 80%, respectively. All patients with pulmonary embolism showed regional perfusion deficits without ventilation abnormality on ventilation‐perfusion MR imaging. The results of the current study indicate that ventilation‐perfusion MR imaging using oxygen inhalation and bolus injection of MR contrast medium is feasible for comprehensive assessment of pulmonary ventilation‐perfusion abnormalities in patients with lung diseases. J. Magn. Reson. Imaging 2001;14:419–424.

Incidence of Aneurysms in Takayasu's Arteritis:

The angiographic findings of Takayasus arteritis in a series of 113 patients were reviewed. Predominant findings were stenotic or occlusive changes, but fusiform or saccular aneurysms were also found in 36 patients (31.9%) in the various sites of aorta and its major branches. Multiple aneurysms were found in 15 patients. The most common site of aneurysms was the ascending aorta (16 patients); in 7 of the patients these were complicated by aortic regurgitation. Aneurysms developed in the aortic arch in 3 patients, in the descending aorta in 11, in the abdominal aorta in 7, and in the major branches of the aortic arch in 9 patients. In 2 patients, follow-up angiograms showed enlargement of the aneu rysms, and rupture of the aneurysm occurred in 1 patient. Aneuryms were found even in young patients. A fifteen-year-old female showed a huge aneurysm in the ascending aorta as the initial manifestation of this disease. Thickening of the walls of aneurysms was common and characteristic. This study revealed the moderately high incidence of aneurysms of various sites of arteries in patients with Takayasus arteritis. The authors conclude that aneurysm, as well as occlusive changes, can be a primary lesion.

Regeneration of the un-embolized liver parenchyma following portal vein embolization

BACKGROUND/AIMS Portal vein embolization (PVE) induces atrophy of the embolized hepatic parenchyma and hypertrophy of the un-embolized liver. It is important to predict hypertrophy of un-embolized liver following PVE to decide a subsequent tactics in patients with liver tumors. The hypertrophy following PVE was evaluated in reference to embolized liver volume and a preceding use of transcatheter hepatic arterial chemoembolization (HACE) in this study. METHODS Thirty patients with liver tumors were studied. PVE was performed transhepatically. Ethanol (15-65 ml) was injected into portal veins, which perfused the liver segment bearing the tumor until occlusion. Embolization was performed at subsegmental portal branches in five patients, segmental branches in 11 patients and right portal veins in 14 patients. Twenty-three patients with underlying chronic liver disease and hepatocellular carcinoma (HCC) underwent PVE 2-6 weeks after HACE. The remaining seven patients without underlying chronic liver disease had bile duct cancer (6) or liver metastasis (1), and underwent PVE alone. Segmental volume in the liver was measured with computed tomography before and 4 weeks after PVE. RESULTS The degree of hypertrophy showed a significant correlation with embolized liver volume (r=0.685, p<0.001). Increase in un-embolized liver volume was 2.4+/-5.8% with subsegmental embolization (NS), 15.2+/-6.4% with segmental embolization (p<0.01) and 46.5+/-18.8% with right PVE (p<0.001). In 14 patients with right PVE, degree of hypertrophy in seven patients with HACE was greater than that in seven patients without HACE (56.7+/-21.6% vs 36.4+/-7.4%; p<0.03). CONCLUSIONS Hypertrophy of the un-embolized liver parenchyma following PVE was correlated with embolized liver volume and was augmented with combined use of HACE.

Assessment of myocardial fibrosis in cardiomyopathic hamsters with gadolinium-DTPA enhanced magnetic resonance imaging

RATIONALE AND OBJECTIVES The authors investigated whether magnetic resonance (MR) imaging enhanced with gadolinium (Gd)-DTPA would be useful for assessment of myocardial fibrosis in cardiomyopathy. METHODS The authors compared MR images of the excised heart after Gd-DTPA injection with histopathologic findings in 33 hamsters with cardiomyopathy of the Bio 14.6 strain and 26 healthy hamsters of various age groups and assessed localization of Gd-14C-DTPA by autoradiography in the myocardium of three hamsters with cardiomyopathy. RESULTS The mean signal intensity ratios for the entire myocardium in hamsters with cardiomyopathy relative to that in healthy hamsters was significantly higher in a younger age group than in an older age group (1.30+/-0.09 versus 1.03+/-0.08, P < 0.001, respectively). This myocardial enhancement was more obvious in areas containing massive fibrosis in the early and mid stages than in the late stage. Autoradiograms of hamsters with cardiomyopathy showed patchy or linear increases in uptake, corresponding to the areas of myocardial fibrosis. Gadolinium-14C-DTPA radioactivity ratios of myocardial fibrosis to healthy myocardium were significantly higher in the early and mid stages than in the late stage (P < 0.01). CONCLUSIONS Myocardial fibrosis with high cellularity and proliferation of vessels was delineated as an area enhanced with Gd-DTPA on MR images, and its signal intensity decreased with the late stage of myocardial fibrosis.

Arterial chemoinfusion therapy through an implanted port system for patients with unresectable intrahepatic cholangiocarcinoma—initial experience

Arterial chemoinfusion therapy through an implanted port system was performed for patients with unresectable intrahepatic cholangiocarcinoma (ICC). Eleven patients with unresectable ICC were studied. Seven patients had stage-IV disease, two had stage-III disease, and two had stage-II disease. The mean tumor size was 7.0+/-2.6 cm (range 3.8-13.5 cm). A catheter and port system was percutaneously implanted, and anticancer drugs featuring fluorouracil were administered via the infusion system every 1-2 weeks on the outpatient basis in all patients except 2. Arterial chemoinfusion therapy was repeated 12-84 times per patient (mean 51 times). Partial and minor responses were achieved in sevenents (64%). Disease was stable in two patients (18%), and progressed in the other two patients (18%). Tumor growth was controlled during a mean period of 14.5 months in seven responders and two patients with stable disease. The survival rates were 91% at 1 year, 51% at 2 years, 20% at 3 years, and 10% at 4 years, respectively. The mean survival period was 26 months. Toxicity such as cholangitis and pancytopenia was found in three patients (27%). This treatment seems to improve the prognosis of patients with unresectable ICC and deserves further studies.

Clinical efficacy of portal vein stent placement in patients with hepatocellular carcinoma invading the main portal vein

BACKGROUND/AIMS Hepatocellular carcinoma frequently invades the portal veins, and when it invades the main portal vein, the patients prognosis is extremely poor. This study was undertaken to evaluate the clinical efficacy of stent placement into the portal vein in these patients. METHODS Twenty-one patients with hepatocellular carcinoma invading the main portal vein were studied. Stents were placed in the portal veins to compress tumor thrombi after percutaneous transhepatic portography. RESULTS Stents were successfully placed in the portal veins in all patients. Portal venous pressure significantly decreased from 25.3 +/- 7.4 mmHg to 22.4 +/- 6.6 mmHg (p < 0.0001) immediately after stent placement, leading to improvement in gastroesophageal varices, melena and ascites. Although a pseudoaneurysm of the hepatic artery related to portal vein puncture developed in one patient, there were no major complications in the other 20 patients. Blood flow through the stent was maintained during the survival period in 15 patients. The mean stent patency period was 12.4 months. Fifteen patients underwent transcatheter arterial chemoembolization without major complications after stent placement. The survival rate was 64.2% at 6 months and 29.2% at 1 and 2 years, respectively. The mean survival period was 13.7 months. CONCLUSION Stent placement into the portal vein is a relatively safe and feasible procedure. It improves portal hypertension, expands treatment options, and helps to prolong the survival period in patients with hepatocellular carcinoma invading the main portal vein.

Fast 3D dynamic MR imaging of the liver with MR SmartPrep: Comparison with helical CT in detecting hypervascular hepatocellular carcinoma

Dynamic magnetic resonance (MR) imaging with SmartPrep was compared with dynamic enhanced helical computed tomography (CT) for the detection of hepatocellular carcinoma (HCC). Thirty patients with 49 HCCs were studied. Arterial-phase MR images using with SmartPrep were significantly superior to arterial-phase CT in detecting small lesions (< or = 2 cm) (85.3% vs. 67.6%, P < .05). In addition, in six recurrent tumors after arterial chemoembolization, dynamic MR imaging with MR SmartPrep technique was superior to helical CT in detecting of recurrent tumors.

Lymphatic Mapping and Sentinel Node Biopsy during Laparoscopic Gastrectomy for Early Cancer

Background/Aims: Intraoperative lymphatic mapping and sentinel node (SN) biopsy can potentially be combined with minimally invasive surgery, but there are few reports of laparoscopic lymphatic mapping for gastrointestinal cancer. We examined the feasibility and accuracy of laparoscopic lymphatic mapping in predicting lymph node status in patients with gastric cancer. Methods: Seventeen patients with gastric cancer invading the mucosal or submucosal layers (T1) underwent laparoscopic gastrectomy with lymphatic mapping between March 2001 and May 2002. The day before surgery, a technetium-99m-labelled tin colloid solution was injected endoscopically around the tumor. Immediately after the pneumoperitoneum, patent blue was injected. Gastrectomy was performed in all patients, and blue-stained or radioactive nodes were defined as SNs. Fresh SNs were immediately processed for frozen-section examination by hematoxylin-eosin (H&E) and immunohistochemical (IHC) staining. All non-SNs harvested from resected specimens were subjected to histological examination with H&E. Results: SNs were detected in all patients by combination of the two kinds of tracers. Three patients had lymph node metastases in their final examination, and SNs in these 3 were operatively diagnosed as positive by H&E or IHC staining. Lymphatic mapping and SN biopsy under laparoscopic surgery were performed with 100% accuracy. Conclusion: Our preliminary study shows the feasibility of intraoperative lymphatic mapping in laparoscopic gastrectomy for T1 gastric cancer.