Biomedical subjects

Kan Takeda

Publications and source records attributed to Kan Takeda.

79 records · Page 5Linked to original sources

PubMedDate not supplied

Percutaneous radiofrequency ablation for the treatment of liver neoplasms in the caudate lobe left of the vena cava: electrode placement through the left lobe of the liver under CT-fluoroscopic guidance.

Five hepatocellular carcinomas and one liver metastasis located in the caudate lobe left of the inferior vena cava were successfully treated by radiofrequency (RF) ablation by placing the RF electrode into each tumor through the left lobe of the liver under the CT-fluoroscopic guidance. All tumors were free of enhancement on dynamic contrast-enhanced CT during the mean follow-up period of 6.3 months. There were no major complications related to the procedures.

Aged↗

PubMedDate not supplied

Tumor seeding following lung radiofrequency ablation: a case report.

Lung radiofrequency (RF) ablation was performed for the treatment of a primary lung cancer measuring 2.5 cm in maximum diameter in a 78-year-old man. A contrast-enhanced computed tomography (CT) study performed 3 months after RF ablation showed incomplete ablation of the lung tumor and the appearance of a chest wall tumor 4.0 cm in maximum diameter that was considered to be the result of needle-tract seeding. RF ablation was performed for the treatment of both the lung and the chest wall tumors. Although tumor enhancement was eradicated in both of the treated tumors, follow-up CT studies revealed diffuse intra-pulmonary metastases in both lungs 2 months after the second RF session. He is currently receiving systemic chemotherapy.

Aged↗

PubMedDate not supplied

Aneurysm shrinkage after endovascular repair of aortic diseases.

BACKGROUND: There are two graft materials for endovascular repair of aortic diseases, i.e., polyester and expanded polytetrafluoroethylene (ePTFE). The latest reports have suggested that there is graft-specific difference in outcomes. The purpose of this article was to evaluate the difference in terms of aneurysm shrinkage. PATIENTS AND METHODS: Eighty-six patients who underwent endovascular repair of aortic diseases were included. Forty patients had true aortic aneurysms, 8 had aortic pseudoaneurysms, and 38 had aortic dissections. Eighteen patients with true aortic aneurysms were treated with stent grafts fabricated with polyester, while the other 68 patients, including 22 patients with true aneurysms, 8 patients with pseudoaneurysms, and 38 patients with aortic dissections, were treated with stent grafts fabricated with ePTFE. All patients were followed-up by computed tomography (CT) for more than 1 year. The mean follow-up term was 28 months. Computed tomography confirmed that there were sufficiently long necks, and the aneurysm or the entry tear was completely excluded without any endoleak in all patients. The diameter of the preoperative lesion was compared with that measured on follow-up CT at 1 year and at the end of the follow-up term. Increase or decrease in the diameter by more than 5 mm was defined as a significant diameter change. RESULTS: Aneurysm shrinkage was observed in 40% of patients with true aneurysms, 88% of patients with pseudoaneurysms, and 55% of patients with aortic dissections at 1 year. There was no significant increase in patients with aneurysm shrinkage at the end of follow-up in any groups. In the case of true aortic aneurysms, shrinkage of aneurysms was observed more frequently with polyester-fabricated stent grafts (67%, 13/18) than with ePTFE-fabricated ones (18%, 4/22) at 1 year (P<.01). In contrast, expansion of aneurysms was observed only in patients treated with ePTFE (14%, 3/22). Shrinkage of the descending aorta was observed in 55% of patients with acute aortic dissections and 36% of patients with chronic aortic dissections. There was no case with aortic enlargement in either group. There was no significant difference between acute and chronic dissection in terms of shrinkage of the descending aorta. CONCLUSION: Expanded polytetrafluoroethylene appears to be effective for the treatment of pseudoaneurysms and aortic dissections. However, polyester seems to be more effective than ePTFE when true aneurysms are to be treated.

Aortic Dissection↗

PubMedDate not supplied

Recanalization and reversal of diffusion abnormalities and markedly reduced cerebral blood volume in a patient with transient ischemic attack.

Resolution of diffusion abnormalities is a finding that is rarely seen in hyperacute cerebral ischemia. We report a serial study of diffusion and perfusion magnetic resonance imaging (MRI) in a case of transient ischemic attack (TIA). In the current case, marked decrease of cerebral blood volume (CBV) as well as reduced diffusion in the affected middle cerebral arterial territory was shown by the initial diffusion and perfusion MRI at 1.5 h after onset. The initial MRI findings as well as neurological symptoms recovered probably due to prompt and spontaneous recanalization of thrombosed vessel.

Aged↗

PubMedDate not supplied

A case of inverted left atrial appendage mimicking a tumor.

We report a rare case of an inverted left atrial appendage without prior cardiac surgery. A left atrial mass was incidentally found during routine echocardiography in a 19-year-old man with mitral valve prolapse. Echocardiography revealed a hyperechoic mass in the left atrium, and a neoplastic lesion could not be excluded. On magnetic resonance imaging (MRI), this mass consisted of fat tissue that showed continuation to epicardial fat, indicating an inverted left atrial appendage mimicking a tumor in the left atrium. When a mass in the left atrium is observed on echocardiography, there are several differential diagnoses, including thrombus, vegetation, and intra-atrial neoplasms such as myxomas. Recently, several studies reported cases with inverted left atrial appendages mimicking tumors in patients after cardiac operations. We present a case of inverted left atrial appendage without any prior cardiac surgery. Cardiac MRI was highly useful to obtain the final diagnosis of inverted left atrial appendage.

Adipose Tissue↗

PubMedDate not supplied

Relationships between head fixation pins for radiosurgery and the skull bone--usefulness of a torque wrench.

BACKGROUND: In stereotactic radiosurgery (SRS), fixation devices are secured to the patient's head with pins. However, there have been no standards for the use of such pins, which must be inserted with appropriate torque based on the surgeon's clinical judgment. Therefore, the pins may sometimes be tightened excessively and penetrate too deeply into the patient's skull. PURPOSE: To improve safety in SRS, a torque wrench was used for pin insertion. The usefulness of the torque wrench was then evaluated by examining the relationships between the pins and skull bone and identifying differences according to the wrench used and the patient's bone thickness. METHODS: CT images of patients who had previously undergone SRS were used to assess the relationships between the pins and skull bone. Differences according to the wrench used and pin insertion site were investigated. RESULTS: Compared with a standard wrench, use of the torque wrench decreased the insertion depth of pins in the skull bone. In terms of site, pins in the forehead were inserted more deeply. No differences related to the frontal sinus were observed. CONCLUSION: The use of a torque wrench improved safety during pin insertion for SRS procedures.

Adolescent↗

PubMedDate not supplied

Repeated hepatic arterial infusion chemotherapy using an implanted port system in patients with unresectable malignant liver neoplasms: significant factors affecting early hepatic arterial occlusion.

The purpose of this study was to identify significant factors affecting early hepatic arterial occlusion in patients who received repeated hepatic arterial infusion chemotherapy using an implanted port system. Eighty-five patients with unresectable liver neoplasms who underwent implantation of the port system were studied. Arterial infusion chemotherapy was performed every 1-4 weeks. Arterial occlusion was evaluated by hepatic arteriography performed via the port every 3 months. Twenty variables were analyzed using univariate and multivariate analyses to identify significant factors affecting early hepatic arterial occlusion. Hepatic arterial occlusion was found in 25.9% (22/85) of the patients. Thirteen of them experienced early arterial occlusion within 6 months. The mean survival period was significantly worse in patients who experienced early arterial occlusion than those who did not (16 months vs. 26 months, p<0.05). In the multivariate analysis, the following 3 variables had independent value for early arterial occlusion; i). diameter of the common hepatic artery, ii). gender, and iii). previous systemic chemotherapy. Early arterial occlusion affects therapeutic effects and survival in patients who undergo arterial infusion chemotherapy with an implanted port. Factors demonstrated here are important to classify patients at risk of early hepatic arterial occlusion.

Adult↗