Yokohama Rosai Hospital

Yokohama-shi, Japan

Yokohama Rosai Hospital

Yokohama-shi, Japan
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Ando T.,Yokohama Rosai Hospital
Kyobu geka. The Japanese journal of thoracic surgery | Year: 2016

During cardiac surgery through midline sternotomy, sternum closure metal wires are usually used for. However, metal wires may damage the sternum and cause artifacts on X-ray. Therefore, we use a novel sternum closure technique in which metal wire is replaced by ultra-high molecular weight polyethylene(UHMWP) sutures. We have used this technique for 89 patients in 2014 and reviewed our experience. UHMWPs are often used for bone fracture cerclage, particularly in the vertebral body. UHMWPs may avoid sternal "cheese-cut" dehiscence.


Morishima I.,Ogaki Municipal Hospital | Nogami A.,Yokohama Rosai Hospital | Tsuboi H.,Ogaki Municipal Hospital | Sone T.,Ogaki Municipal Hospital
Journal of Cardiovascular Electrophysiology | Year: 2012

Left Posterior Fascicle and Idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the sinus beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium. © 2012 Wiley Periodicals, Inc.


Shuto T.,Yokohama Rosai Hospital | Yagishita S.,Kanagawa Rehabilitation Hospital | Matsunaga S.,Yokohama Rosai Hospital
Acta Neurochirurgica | Year: 2015

Background: The pathological characteristics of cyst development after gamma knife surgery (GKS) for arteriovenous malformation (AVM) were analysed.Method: Sixteen male and 12 female patients aged 17–67 years (mean 31.3 years) were retrospectively identified among 868 patients who underwent GKS for AVM at our hospital. The pathological characteristics of the reddish nodular lesion and chronic encapsulated expanding haematoma associated with cyst following GKS for AVM were examined.Results: Cyst was associated with chronic encapsulated expanding haematoma in 13, and with nodular lesion in 12 patients. The nidus volume at GKS was 0.1–36 ml (median 6.0 ml), and the prescription dose at the nidus margin was 18–25 Gy (median 20 Gy). Cyst formation was detected from 1.1 to 16 years (mean 7.3 years) after GKS. Seven of the 12 patients with nodular lesion underwent surgery. Ten of the 13 patients with expanding haematoma underwent surgical removal of expanding haematoma. Histological examination was possible in 17 cases. Dilated capillary vessels with wall damage such as hyalinisation and fibrinoid necrosis, marked protein exudation and haemorrhage were the most common findings. Brain parenchyma was observed among the dilated vessels in some cases. Structureless necrotic tissue was not evident.Conclusions: The present study suggests that enhanced nodular lesion on magnetic resonance imaging and chronic encapsulated expanding haematoma associated with cyst may have common aetiopathology caused by late radiation effects, mainly consisting of dilated capillary vessels with wall damage. Massive protein exudation from such damaged capillary vessels is important in cyst development. © 2014, Springer-Verlag Wien.


The authors retrospectively studied the mechanism of cyst formation and enlargement after Gamma Knife surgery (GKS) for arteriovenous malformations (AVMs). Eighteen patients in whom cyst formation developed following GKS for AVM were retrospectively identified among 775 patients who underwent GKS for AVM at Yokohama Rosai Hospital. The study group was composed of 12 male and 6 female patients ranging in age from 17 to 47 years. Chronic encapsulated expanding hematoma was associated with the cyst in 5 patients. The AVM nidus volume at the time of GKS ranged from 1.9 to 36 cm(3), and the prescription radiation dose was 18-25 Gy. Complete obliteration of the AVM nidus was obtained in 13 patients and partial obliteration in 5 patients. Cyst formation was detected between 2.6 and 15 years after GKS. Craniotomy was performed in 10 patients, including 2 patients in whom the incompletely obliterated nidus was removed at the same time, and an Ommaya reservoir was placed in 2 patients. Spontaneous regression of the cyst was observed in 1 patient. Serial MR imaging was performed in the other patients because the size of the cyst was stable or the lesion was asymptomatic. Histological examination of the cyst wall revealed linear hemosiderin deposits with gliosis. The nodular lesion, which was enhanced on MR images, contained granulation tissue with chronic hemorrhage from newly developed capillary vessels. Cysts developing after GKS for AVM enlarge mainly due to repeated minor hemorrhages from a reddish nodular angiomatous lesion that develops within an adjacent brain area. Thus, the optimal treatment is wide opening of the cyst with removal of the associated angiomatous lesion by craniotomy.


Nogami A.,Yokohama Rosai Hospital
PACE - Pacing and Clinical Electrophysiology | Year: 2011

There has been growing evidence that the Purkinje network plays a pivotal role in both the initiation and perpetuation of ventricular fibrillation (VF). A triggering ventricular premature beat (VPB) with a short-coupling interval could arise from either the right or left Purkinje system in patients with polymorphic ventricular tachycardia (VT) or VF, and that can be suppressed by the catheter ablation of the trigger. A focal breakdown in the "gating mechanism" at the Purkinje system resulting in a short-circuiting of the transmission across the gate at the distal Purkinje network might predispose to reentrant circuits of polymorphic VT/VF. Many investigators also reported the successful ablation of Purkinje-related VF with an acute or remote myocardial infarction. The same approach with good short-term results has been reported in a small number of patients with other heart diseases (i.e., amyloidosis, chronic myocarditis, nonischemic cardiomyopathy). Catheter ablation of the triggering VPBs from the Purkinje system can be used as an electrical bailout therapy in patients with VF storm. © 2010 Wiley Periodicals, Inc.


Akihiko N.,Yokohama Rosai Hospital
PACE - Pacing and Clinical Electrophysiology | Year: 2011

Purkinje-related monomorphic ventricular tachycardias (VTs) can be classified into four distinct groups: (1) verapamil-sensitive left fascicular VT, (2) Purkinje fiber-mediated VT post infarction, (3) bundle branch reentry (BBR) and interfascicular reentry VTs, and (4) focal Purkinje VT. There are three subtypes of fascicular VTs: (1) left posterior fascicular VT with a right bundle branch block (RBBB) configuration and superior axis; (2) left anterior fascicular VT with an RBBB configuration and right-axis deviation; and (3) upper septal fascicular VT with a narrow QRS configuration. The mechanism of the fascicular VT is macroreentry. While the antegrade limb of the circuit is amidseptal abnormal Purkinje fiber in the anterior and posterior fascicular VTs, the antegrade limb of the upper septal fascicular VT is both the anterior and posterior fascicles, and the retrograde limb is a midseptal abnormal Purkinje fiber. Purkinje fibermediated VT post infarction also exhibits verapamil sensitivity, and the surviving muscle bundles within the myocardium and Purkinje system are components of the reentry circuit. BBR-VT and interfascicular reentry VT are amenable to being cured by the creation of bundle or fascicular block. The mechanism of focal Purkinje VT is abnormal automaticity from the distal Purkinje system, and the ablation target is the earliest Purkinje activation during the VT. It is difficult to distinguish verapamil-sensitive fascicular VT from focal Purkinje VT by the 12-lead electrocardiogram; however, focal Purkinje VT is not responsive to verapamil. The recognition of the heterogeneity of these VTs and their unique characteristics should facilitate an appropriate diagnosis and therapy. ©2011, The Author. Journal compilation ©2011 Wiley Periodicals, Inc.


Objective: To explore simpler and possibly more appropriate tools than the conventional Disease Activity Score 28 (DAS28) for assessing rheumatoid arthritis (RA) and to derive more reliable DAS28-based criteria. Methods: The capabilities of assessing disease activities in 250 RA patients were compared between DAS28 and other methods, including the Simplified DA Index (SDAI), Clinical DA Index (CDAI), and Routine Assessment of Patient Index Data-3 (RAPID-3). Results: SDAI and CDAI showed a good correlation and consistency with DAS28, whereas RAPID-3 yielded inferior results. In terms of remission criteria, DAS28 was less stringent than SDAI or CDAI; when RA remission was reexamined based on more stringent SDAI or CDAI criteria, cut-off values for DAS28-C-reactive protein of < 1.72 were considered to be appropriate. The conventional DAS28 was considered to be appropriate for assessing low, middle and high disease activities because it provides criteria similar to or more stringent than those of other methods, while SDAI and CDAI were considered to be simpler and more appropriate criteria for assessing remission. Conclusion: For assessing remission, DAS28-CRP provides the most appropriate criterion of the methods compared when the currently used cut-off value of 2.3 is lowered to a new value of 1.72. © Japan College of Rheumatology 2012.


The prognosis of metastatic or recurrent gastrointestinal stromal tumors (GISTs) accompanied by multiple hepatic metastases and peritoneal dissemination is very poor. We encountered a case of stage IV small intestinal GIST with multiple hepatic metastases and peritoneal dissemination that were observed after resection of the primary lesion. Multidisciplinary treatments were performed over time, including hepatic resection, radiotherapy, imatinib therapy, sunitinib therapy, and transcatheter arterial chemoembolization, and the disease had been brought under control following resection of a primary lesion 14 years ago. The patient was a 49-year-old woman diagnosed with hemorrhagic stool in July 1998, when a computed tomography scan revealed an 8-cm-diameter tumor in her small bowel. Partial resection of her small bowel was performed and the pathological diagnosis was a high-risk GIST showing 15 mitoses per 50 high power fields. Several metastases developed in the S4 and S5 segments of the patient's liver 3 years after resection of the primary lesion, and a central two-segmental resection of the liver was performed. Furthermore, 1 year after this procedure, peritoneal dissemination developed near the pancreas, for which radiotherapy was performed. Four months later, the patient again developed multiple liver metastases and was started on treatment with 400 mg imatinib per day, achieving a partial response(PR). Five years and 6 months after imatinib initiation, resistance emerged in one of the liver metastases. The patient was switched to sunitinib(50 mg per day), but was diagnosed with progressive disease at the end of the second course and the procedure was discontinued. Treatment with 400 mg of imatinib per day was resumed, and transcatheter arterial chemoembolization was performed twice over a 17-month period for the resistant hepatic region and a PR was achieved each time. We were able to maintain a PR in this patient; other metastases indicated the effectiveness of imatinib therapy. Therefore, a multidisciplinary team approach can be effective in achieving long-term disease control in patients with metastatic or recurrent GIST.


The goal of this study was to analyze prognostic factors for local tumor control and survival and indications for initial treatment with the Gamma Knife in patients with up to 10 metastatic brain tumors from primary breast cancer. Outcomes were retrospectively reviewed in 101 women with a total of 600 tumors, who underwent Gamma Knife surgery (GKS) for metastatic brain tumors between April 1992 and December 2008 at 1 institution. The inclusion criteria were up to 10 brain metastases, maximum diameter of tumor < 3 cm, and total tumor volume < 15 cm(3). The exclusion criteria were poor systemic condition, presence of carcinomatous meningitis, and previous whole brain radiation treatment and/or craniotomy. The mean tumor volume at GKS was 3.7 cm(3) (range 0.016-14.3 cm(3)). The mean margin dose was 19 Gy (range 8-30 Gy). Neuroimaging showed that the local tumor growth control rate was 97%, and the tumor response rate was 82.3%. Larger tumor volume (p = 0.001) and lower margin dose (p = 0.001) were significant adverse prognostic factors for local tumor growth control according to a multivariate analysis. The number of brain metastatic lesions was 4 or fewer in 76 patients and 5 or more in 25 patients. The median overall survival time was 13 months. Multivariate analysis revealed that the presence of extracranial metastases (p = 0.041) and lesions that were not the human epidermal growth factor receptor-2 (HER2)-positive type (p = 0.001) were significant adverse prognostic factors for overall survival. The number of brain metastases was not statistically significant, except for a single metastasis. The median new lesion-free survival time after initial GKS was 9 months. Five or more lesions at initial GKS (p = 0.007) and younger patient age (p = 0.008) reduced survival significantly. The prevention of neurological death after GKS was 93.9% at 1 year, and a lower Karnofsky Performance Scale score (p = 0.009) was the only unfavorable factor. Median overall survival associated with the HER2-positive phenotype was significantly longer than survival associated with the other phenotypes (luminal and triple-negative). There were no statistically significant differences between the 3 breast cancer phenotypes for the incidence of new brain metastases after initial GKS. Initial GKS resulted in excellent local tumor control rates, which were associated with prolonged survival and a low risk of neurological death for patients with up to 10 metastatic brain tumors from primary breast cancer. The authors recommend periodic clinical and neuroradiological follow-up examinations after GKS in patients with 5 or more lesions at initial GKS, because they carry a high risk of development of new brain metastases, and in patients with the HER2-positive phenotype, because they tend to have a favorable prognosis in overall survival. Last, the authors recommend additional GKS or whole-brain radiation treatment for salvage treatment if new brain metastases occur.


In order to promote consensus building on decommissioning operation rules for medical linear accelerators in Japan, we carried out a risk communication (RC) approach mainly providing knowledge for maintenance staff regarding induced radioactivity. In February 2012, we created a booklet (26 pages) to present an overview of the amended law, the mechanism and the distribution of induced radioactivity showing the actual radiation dose rate around a linear accelerator and actual exposure doses to staff. In addition, we co-sponsored a seminar for workers in this field organized by the Japan Medical Imaging and Radiological Systems Industries Association to explain the contents of this booklet, and answer questions regarding induced radioactivity of linear accelerators as an RC program. As a result, the understanding of staff regarding the regulations on maximum X-ray energy on linear accelerators (P<0.05), and the outline of clearance systems (P<0.01), were facilitated by RC. In addition, we found that about 70% of maintenance staff considered that the cooling time for decommissioning operation depended on the situation. Our RC approach suggests that consensus building should be used to make rules on decommissioning operations for linear medical accelerators.

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