Publications by authors named "Shinichi Hamamoto"

We report a rare case of retroperitoneal pseudotumor caused by that was diagnosed by computed tomography (CT) guided percutaneous biopsy in a 15-year-old Filipino male. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass lesion, including a mesenteric artery, in the right retroperitoneal space. His mother had a history of infection but his initial stool examination was negative.

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A 66-year-old man presented with liver cirrhosis due to non-alcoholic steatohepatitis and hyperammonemia. Contrast-enhanced CT showed a dilated and tortuous splenorenal shunt and a large venous aneurysm in the shunt. The venous aneurysm showed gradual enlargement over 10 years and worsening hyperammonemia, so balloon-occluded retrograde transvenous obliteration was performed.

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Purpose: To evaluate whether early chest computed tomography (CT) lesions quantified by an artificial intelligence (AI)-based commercial software and blood test values at the initial presentation can differentiate the severity of COVID-19 pneumonia.

Materials And Methods: This retrospective study included 100 SARS-CoV-2-positive patients with mild (n = 23), moderate (n = 37) or severe (n = 40) pneumonia classified according to the Japanese guidelines. Univariate Kruskal-Wallis and multivariate ordinal logistic analyses were used to examine whether CT parameters (opacity score, volume of opacity, % opacity, volume of high opacity, % high opacity and mean HU total on CT) as well as blood test parameters [procalcitonin, estimated glomerular filtration rate (eGFR), C-reactive protein, % lymphocyte, ferritin, aspartate aminotransferase, lactate dehydrogenase, alanine aminotransferase, creatine kinase, hemoglobin A1c, prothrombin time, activated partial prothrombin time (APTT), white blood cell count and creatinine] differed by disease severity.

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Purpose: This study evaluated the survival benefit of a combination therapy with radiofrequency ablation (RFA) and intratumoral cisplatin (ITC) administration for lung tumors by using a rabbit VX2 tumor model.

Materials And Methods: Experiments were approved by the institutional animal care committee. VX2 tumor suspension was injected into the lungs of Japanese white rabbits under CT guidance to create a lung tumor model.

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Treatment options for metastatic osteosarcoma are limited. The present study aimed to evaluate whether radiofrequency ablation (RFA) combined with intratumoural OK-432 injection induces systemic anti-tumour immunity in rat osteosarcoma model. Eighty of 145 rats were assigned to four groups to evaluate overall survival and tumour size: control (no treatment), RFA-only, OK-432, and RFA-OK-432.

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Objective: To determine the utility of low-dose gelatin sponge particles and 5% ethanolamine oleate iopamidol (EOI) mixture in retrograde transvenous obliteration (GERTO) for gastric varices (GV).

Methods: 57 consecutive patients who underwent balloon-occluded retrograde transvenous obliteration (B-RTO) for GV were divided into three groups with Hirota's grade by balloon-occluded retrograde transvenous venography. Hirota's Grade 1 patients were assigned to G1 group and underwent treatment with 5% EOI.

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Purpose: To investigate the technical feasibility, safety and clinical outcomes of coil-assisted retrograde transvenous obliteration II (CARTO-II) for gastric varices (GV).

Materials And Methods: Thirty-six consecutive patients who had undergone CARTO-II between June 2016 and April 2018 were included in the study. In the CARTO procedure, coil embolization of the drainage vein is performed "before" injection of the sclerosant to replace the use of balloon catheter.

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Objective Therapeutic predictors derived from the venous pressure before therapy have not been identified for Budd-Chiari syndrome (BCS). The aim of this study was to determine whether or not measuring the distal pressure or pressure gradient was useful for predicting treatment efficacy in BCS. Methods We retrospectively analyzed seven consecutive patients diagnosed with symptomatic BCS at our hospital between 2008 and 2017.

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Objective Balloon-occluded retrograde transvenous obliteration (B-RTO) for gastric varices (GV) is associated with drawbacks including a postoperative increase in portal pressure and the risk of subsequent worsening of esophageal varices (EV). Selective B-RTO that embolizes only the varices may have the potential to minimize such risks. The aim of this study is to retrospectively compare the postoperative course of patients after selective B-RTO (Group S) and conventional B-RTO (Group B).

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Purpose: To identify the risk factors for local recurrence in hepatocellular carcinoma (HCC) patients treated with transcatheter arterial chemoembolization (TACE) with drug-eluting beads (DEB-TACE).

Materials And Methods: In this retrospective study, 35 patients (27 males, 8 females; median age 73 years) with 116 tumors (median size 14 mm) treated with DEB-TACE from May 2014 to September 2018 were evaluated. Age, sex, etiology, Child-Pugh class, alpha-fetoprotein, des-gamma-carboxyprothrombin, previous conventional TACE, tumor location, tumor size, tumor number, contact with the liver surface, level of embolization, corona enhancement on CT during hepatic arteriography, vascular lakes, additional embolization with gelatin sponge particles, and supplying vessels on digital subtraction angiography (DSA) after embolization were analyzed.

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Objective: Radiofrequency ablation (RFA) is less effective for large tumors > 3 cm in diameter. Various studies of combination therapy using RFA and other treatments have been conducted to improve the results of RFA treatment of lung tumors, survival was extended in a tumor model when RFA was followed by concomitant use of systemic chemotherapy. Bevacizumab (BCM) is a one of molecular target drugs.

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Purpose To evaluate survival time with concurrent, combined use of radiofrequency ablation (RFA) and one of the commonly used platinum-doublet chemotherapies (cisplatin [CDDP]/paclitaxel [PTX], CDDP/vinorelbine [VNR], CDDP/adriamycin [ADR], or CDDP/pemetrexed [MTA] combinations) by using a rabbit VX2 lung tumor model. Materials and Methods The experiment was approved by the institutional animal care committee. VX2 cells were implanted into the lungs of 60 rabbits randomized into groups treated with supportive care (control group), RFA alone, chemotherapy alone (CDDP/PTX, CDDP/VNR, CDDP/ADR, or CDDP/MTA), or a combination of RFA and chemotherapy (RFA/CDDP/PTX, RFA/CDDP/VNR, RFA/CDDP/ADR, or RFA/CDDP/MTA).

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Purpose: To investigate predictive factors and cutoff value of transient elastography (TE) measurements for assessing improvement in liver function after balloon-occluded retrograde transvenous obliteration (BRTO) for gastric varices (GV).

Materials And Methods: Retrospective analysis was performed of 50 consecutive patients followed for > 3 months after BRTO, who had undergone TE before BRTO between January 2011 and February 2015. The correlation between change in liver function (total bilirubin, albumin, and prothrombin time) and baseline liver function values and liver stiffness measurement (LSM) by TE was evaluated by Pearson correlation test.

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Objective: The purpose of this study was to retrospectively evaluate the effectiveness of the model for end-stage liver disease (MELD) score compared with the Child-Pugh classification in patients who received three-dimensional conformal radiotherapy (3D CRT) for hepatocellular carcinoma (HCC) with portal vein tumour thrombosis (PVTT) by analyzing toxicity and prognostic factors.

Methods: 56 consecutive patients who had locally advanced HCC with PVTT treated by 3D CRT between September 2007 and April 2013 were retrospectively reviewed.

Results: The median survival time of all patients was 6.

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Background: Focal stenosis or occlusion of the infrarenal aorta is rare, and treatment is usually conventional bypass or endarterectomy. However, endovascular treatment has advanced in recent years. The purpose of this retrospective study is to report the results of primary stenting for focal infrarenal aortic occlusive disease and clarify the usefulness of endovascular treatment.

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Purpose: To evaluate whether the combination of radiofrequency (RF) ablation and local injection of the immunostimulant Mycobacterium bovis bacillus Calmette-Guérin (BCG) induces systemic antitumor immunity.

Materials And Methods: Japanese White rabbits with lung and auricle VX2 tumors were randomized into three groups: control (n = 8; no treatment), RF ablation only (n = 8; RF ablation to the lung tumor), and RF ablation with local BCG injection into the lung tumor (n = 8). Treatments were performed 1 week after tumor implantation.

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Article Synopsis
  • This text discusses a case series of palliative radiofrequency ablation (RFA) used to alleviate pain and motor function issues in patients with tumors, showing positive outcomes.
  • Two specific cases are highlighted: a 64-year-old woman with a sacral chordoma whose symptoms resolved one year after RFA, and a 68-year-old man with a lung leiomyosarcoma whose symptoms improved three months post-RFA.
  • The study concludes that RFA can be an effective alternative palliative treatment when other conventional methods like surgery or chemotherapy are not suitable.
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Purpose: To examine differences in neointimal hyperplasia (NIH) after placing a self-expanding (SE) stent across size-discrepant vessels.

Materials And Methods: The subjects were 6 beagles, and the target vessels were the abdominal aorta and the external iliac artery (EIA). A nitinol SE stent was placed which was normal-sized in the aorta and oversized in the EIA.

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Purpose: Balloon-occluded retrograde transvenous obliteration (B-RTO) has shown great potential in controlling acute gastric variceal hemorrhage, although rebleeding related to the procedure may occur in a small percentage of patients. The purpose of this study was to identify risk factors of perioperative rebleeding and prognostic factors of postoperative survival in B-RTO performed for acute episodes of gastric variceal hemorrhage.

Methods: We retrospectively analyzed 39 consecutive patients who underwent B-RTO for gastric variceal rupture at our hospital between June 2003 and May 2011.

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Purpose: To evaluate survival and distant tumor growth after radiofrequency ablation (RFA) and local OK-432 injection at a single tumor site in a rabbit model with intra- and extrahepatic VX2 tumors and to examine the effect of this combination therapy, which we termed immuno-radiofrequency ablation (immunoRFA), on systemic antitumor immunity in a rechallenge test.

Methods: Our institutional animal care committee approved all experiments. VX2 tumors were implanted to three sites: two in the liver and one in the left ear.

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Purpose: To evaluate whether antitumor immunity is enhanced systemically by combining radiofrequency ablation (RFA) and local injection of an immunostimulant, OK-432.

Materials And Methods: Experiments were approved by the institutional animal care committee. Experimental Japanese rabbits inoculated with VX2 tumors in the lung and the auricle were randomized into four groups of eight: control (supportive care), RFA (RFA of lung tumor), OK-432 (direct injection of OK-432 into lung tumor), and combination therapy (lung RFA and direct OK-432 injection into lung tumor).

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We report a case of serious complications following computed tomography (CT)-guided radiofrequency ablation (RFA) performed for the treatment of lung cancer with interstitial pneumonia. The patient developed delayed-onset pyopneumothorax, which required 6 months of antibiotic treatment, drainage, and video-assisted thoracoscopic debridement. Although CT-guided RFA is a promising, effective procedure for difficult-to-treat lung cancer, the present case suggests a risk of complications for patients complicated with interstitial pneumonia and warrants caution.

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Purpose: The aim of this study was to examine the actual temperature during lung radiofrequency ablation (RFA) and pathological changes due to thermal damage in the pleural tissue of the chest wall in a rabbit model.

Material And Methods: The study was conducted on 14 Japanese white rabbits with normal lungs. Under computed tomography guidance, the electrode with a 2-cm expandable tip was inserted into the lower lung lobe and positioned so the tip of the needle touched the thoracic wall upon expansion.

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