A case of Schistosoma japonicum retroperitoneal pseudotumor diagnosed by cone-beam CT-guided coaxial biopsy system.

We report a rare case of retroperitoneal pseudotumor caused by Schistosoma japonicum 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 S. japonicum infection but his initial stool examination was negative. As schistosomiasis was suspected, cone-beam CT-guided biopsy was performed to enable transcatheter therapeutic arterial embolization to be performed immediately in the event of hemorrhage. Histopathological examination revealed schistosomal eggs. Cone-beam CT-guided technique with a coaxial biopsy system is a safe and accurate diagnostic procedure for S. japonicum retroperitoneal pseudotumor.

Quantitative evaluation of COVID-19 pneumonia severity by CT pneumonia analysis algorithm using deep learning technology and blood test results.

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. RESULTS: All CT parameters and all blood test parameters except procalcitonin and APPT were significantly different among mild, moderate and severe groups. By multivariate analysis, mean HU total and eGFR were two independent factors associated with severity (p < 0.0001). Cutoff values for mean HU total and eGFR were, respectively, - 801 HU and 77 ml/min/1.73 m2 between mild and moderate pneumonia and - 704 HU and 53 ml/min/1.73 m2 between moderate and severe pneumonia. CONCLUSION: The mean HU total of the whole lung, determined by the AI algorithm, and eGFR reflect the severity of COVID-19 pneumonia.

A case of venous aneurysm of a splenorenal shunt.

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. Under balloon occlusion, 5% ethanolamine oleate was injected from a microcatheter into the venous aneurysm, which was subsequently embolized with microcoils. Contrast-enhanced CT after the procedure showed complete thrombosis of the venous aneurysm. 10 months later, the venous aneurysm reduced in size, and hyperammonemia had improved.

Survival Benefit of Radiofrequency Ablation with Intratumoral Cisplatin Administration in a Rabbit VX2 Lung Tumor Model.

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. Thirty-two rabbits bearing a transplanted VX2 lung tumor were randomly assigned to four groups of eight: control (untreated); RFA alone; ITC alone; and RFA with ITC. All treatments were performed one week after tumor transplantation. Kaplan-Meier survival curves were compared by the log-rank test. RESULTS: The median survival time was 24.5 days (range 17-33 days) in the control group, 40 days (30-80 days) in the RFA alone group, 31.0 days (24-80 days) in the ITC alone group, and not reached (53-80 days) in the RFA with ITC group. The median survival was significantly longer with the RFA/ITC combination compared to the control group (P < 0.001), RFA alone (P = 0.034), and ITC alone (P = 0.004). The survival time after RFA alone was also significantly longer than that of the control group (P < 0.001). There was no significant difference in tumor size or the rate of pneumothorax between each group. CONCLUSION: RFA prolonged the survival of rabbits with lung VX2 tumors when combined with ITC.

Promising abscopal effect of combination therapy with thermal tumour ablation and intratumoural OK-432 injection in the rat osteosarcoma model.

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. The remaining 65 were assigned for histological examination. Maximum diameters of tibial and lung tumours were determined. Tumour samples were histologically examined using haematoxylin-eosin and immunohistochemical staining. Overall survival was significantly prolonged in the RFA-OK-432 group compared to the RFA-only and OK-432 groups. Only rats in the RFA-OK-432 group exhibited significant decreases in maximum tumour diameter after treatment. Ki-67-positive tumour cells in the RFA-OK-432 group were significantly stained negative on immunohistochemical analysis as opposed to those in the RFA-only and OK-432 groups. The number of CD11c+, OX-62+, CD4+, and CD8 + cells significantly increased in the RFA-OK-432 group compared to the RFA-only group. RFA with intratumoural OK-432 injection resulted in distant tumour suppression, prolonged survival, and increased dendritic cells, cytotoxic T cells, IFN-γ, and TNF-α, whereas RFA or OK-432 alone did not produce this effect. This combination may induce an abscopal effect in human osteosarcoma.

Utility of low-dose gelatin sponge particles and 5% ethanolamine oleate iopamidol mixture in retrograde transvenous obliteration (GERTO) for gastric varices.

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. Grade ≥ 2 patients prior to August 2015 were G ≥ 2 group treated with 5% EOI, and those treated thereafter were GERTO group. The amount of EOI used per unit GV volume (EOI/GV ratio), the times to embolization and recurrence rate of GV were evaluated. RESULTS: The EOI/GV ratio was 0.66 ± 0.19 in G1, 1.5 ± 0.8 in G ≥ 2, and 0.58 ± 0.23 in GERTO (G ≥ 2 vs GERTO, p < 0.0001). The times to embolization were 26.5 ± 10.5 min for G1, 39.2 ± 26.8 for G ≥ 2, and 21.4 ± 9.4 for GERTO (G ≥ 2 vs GERTO, p = 0.005). The recurrence rate was not significantly different in any of the groups. CONCLUSION: GERTO was performed in lower amount of sclerosants and in less time compared to conventional B-RTO in Hirota's grade ≥2. ADVANCES IN KNOWLEDGE: Feasibility of low-dose gelatin sponge particles and 5% EOI mixture as sclerosants for GV.

Utility of Coil-Assisted Retrograde Transvenous Obliteration II (CARTO-II) for the Treatment of Gastric Varices.

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. In the CARTO-II procedure, coil embolization of the drainage vein was performed "after" injection of the sclerosant to prevent migration of the sclerosant. CARTO-II was performed with ethanolamine oleate iopamidol, and the balloon catheter was immediately removed after coil placement. Technical and clinical success rates, number of coils used, presence or absence of severe complications, timing of the procedure, and rate of GV recurrence after the procedure were analyzed retrospectively. RESULTS: In all patients, GV sclerosis, coil placement and removal of the balloon catheter were successfully completed. The technical success rate was 100%. No patients experienced severe complications such as coil migration or pulmonary embolization. The mean number of metallic coils used per procedure was 3.36. Mean length of the procedure was 132.8 min. Contrast-enhanced computed tomography after CARTO-II confirmed complete variceal thrombosis in all cases. The recurrence rate of GV during follow-up was 2.8% (mean follow-up, 207 days). CONCLUSION: CARTO-II was feasible and safe and could be performed relatively quickly. The number of coils used and the rate of GV recurrence were both low. CARTO-II may have an important role to play in the management of GV.

Usefulness of Venous Pressure Measurement in Endovascular Treatment of Budd-Chiari Syndrome: A Retrospective Cohort Study.

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. Distal and proximal venous pressures at occlusion sites of BCS were measured before treatment in all cases. The pressure gradient was defined as the difference between distal and proximal venous pressures. A receiver operating characteristics (ROC) analysis was performed for venous pressures. Results Percutaneous old balloon angioplasty (POBA) was performed in seven cases, with technical success achieved in all cases (100%). No complications were encountered. The median primary patency was 574 (interquartile range, 439.5-1,056.5) days. The 1-year primary patency rate was 71.73%. Six cases (85.7%) showed resolution of symptoms, representing clinical success. The ROC analysis revealed a high distal pressure (area under the ROC curve = 0.83, cut-off=12 mmHg) as a predictor of treatment efficacy of POBA for symptomatic BCS. In addition, the pressure gradient was considered significant from a clinical perspective, because the 6 successful cases with resolution of symptoms showed a large pressure gradient (range, 8-21 mmHg) before treatment, whereas the failed case showed a relatively small pressure gradient (7 mmHg). Conclusion High distal pressure and a large pressure gradient might predict the treatment efficacy of balloon angioplasty for symptomatic BCS.

Selective Balloon-occluded Retrograde Transvenous Obliteration for Gastric Varices.

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). Methods One hundred four patients treated from January 2007 to April 2012 were classified into Groups S (n=5) and B (n=99). In the univariate analysis, the volume of 5% ethanolamine oleate iopamiodol (EOI) administered at baseline and the GV blood flow on endoscopic ultrasound after B-RTO were considered as covariates. The rates of GV recurrence and EV aggravation was also compared between Groups B and S. Results In Group S, the volume of 5% EOI was significantly lower (Group S vs. Group B: 14.6±5.5 vs. 28.5±16.4 mL; p=0.0012) and the rate of EV aggravation was lower in comparison to Group B (p=0.045). However, in Group S, the rate of complete eradication of GV blood flow was significantly lower (Group S vs. Group B: 0% vs. 89.9%; p<0.001) and the rate of re-treatment for GV was higher in comparison to Group B (Group S vs. Group B: 60% vs. 1.0%; p<0.001). Conclusion Selective B-RTO for GV could minimize the risk of a worsening of EV or reduce the amount of sclerosants; however, the rate of recurrence was high in comparison to conventional B-RTO.

Risk factors for local recurrence of hepatocellular carcinoma after transcatheter arterial chemoembolization with drug-eluting beads (DEB-TACE).

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. RESULTS: Univariate analysis showed that advanced age, female, large tumor, contact with the liver surface, and residual supplying vessels were significant risk factors for local recurrence (p = 0.012, 0.0013, 0.0023, 0.025, and < 0.001, respectively). On multivariate logistic analysis, large tumor, contact with the liver surface, and residual supplying vessels on DSA were significant risk factors for local recurrence (p = 0.0026, 0.038, and < 0.001, respectively). CONCLUSION: Large tumor size, contact with the liver surface, and residual supplying vessels on DSA were significant risk factors associated with local recurrence after DEB-TACE for HCC.

Combination therapy involving radiofrequency ablation and targeted chemotherapy with bevacizumab plus paclitaxel and cisplatin in a rabbit VX2 lung tumor model.

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. Numerous clinical trials and reports have shown BCM's effect when used in combination with cisplatin (CDDP) in lung tumor. Our objective is to evaluate the survival of concurrent, combined use of radiofrequency ablation and BCM, and platinum-doublet chemotherapy [CDDP/paclitaxel (PTX)] in a rabbit VX2 lung tumor. RESULTS: Survival times of the RFA alone, CDDP/PTX, CDDP/PTX/BCM, RFA/CDDP/PTX, and RFA/CDDP/PTX/BCM groups were significantly prolonged compared to that of the control group (P = 0.0055, P = 0.0055, P = 0.0004, P = 0.0002, P = 0.0019, respectively). Survival of the RFA/CDDP/PTX/BCM group was not significantly prolonged compared to the RFA alone (P = 0.53) and CDDP/PTX/BCM group (P = 0.68), while showing a significantly shorter survival time than that of the RFA/CDDP/PTX group (P = 0.017). The addition to BCM with combination RFA and systemic therapy with CDDP/PTX did not have a positive effect on survival.

Therapeutic Effects of CT-guided Radiofrequency Ablation with Concurrent Platinum-Doublet Chemotherapy in a Rabbit VX2 Lung Tumor Model.

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). RFA was performed and followed by intravenous chemotherapy. Survival time was evaluated by using the Kaplan-Meier method. Results The median survival time of the control, RFA-alone, CDDP/PTX, CDDP/VNR, CDDP/ADR, CDDP/MTA, RFA/CDDP/PTX, RFA/CDDP/VNR, RFA/CDDP/ADR, and RFA/CDDP/MTA groups was 26.5, 40, 39, 26.5, 28, 26, 120, 16.5, 42, and 26.5 days, respectively. Survival of the RFA/CDDP/PTX group was significantly longer than that of the control (P = .0006), CDDP/PTX (P = .0117), and RFA-alone (P = .0495) groups. Survival was also significantly prolonged with combined RFA/CDDP/ADR treatment versus supportive care (P = .026), but not with RFA alone (P = .765) or CDDP/ADR (P = .167). Survival times in the RFA/CDDP/VNR and RFA/CDDP/MTA groups were significantly shorter than that in the RFA-alone group (P = .0282 and P = .0197, respectively). Conclusion The combination of RFA and systemic chemotherapy with CDDP/PTX may benefit survival. However, RFA with systemic CDDP may have a survival disadvantage when combined with VNR or MTA. © RSNA, 2016.

Prediction for Improvement of Liver Function after Balloon-Occluded Retrograde Transvenous Obliteration for Gastric Varices to Manage Portosystemic Shunt Syndrome.

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. Receiver operating characteristic curves were used to determine cutoff values for discriminating between patients who had improved liver function and patients who did not. The time interval from BRTO to aggravation of esophageal varices (EV) (worsening morphology, development of new varices, or variceal rupture) grouped by cutoff values was also analyzed. RESULTS: Serum albumin was significantly improved at 3 months after BRTO (3.57 g/dL vs 3.74 g/dL, P < .001). There was a significant negative correlation between change in albumin and baseline LSM (r = -0.50, P < .001). The best cutoff point for LSM was ≤ 22.9 kPa, with sensitivity and specificity of 78.4% and 69.2%, respectively, for predicting which patients would have improved albumin after BRTO. Among 33 patients, 29 (88%) patients had improved albumin. The 1-year progression rate of EV after BRTO was 13.6% in patients with LSM ≤ 22.9 kPa. CONCLUSIONS: The predictive factor for improvement in albumin after BRTO was lower LSM (≤ 22.9 kPa) using TE.

Three-dimensional conformal radiotherapy for locally advanced hepatocellular carcinoma with portal vein tumour thrombosis: evaluating effectiveness of the model for end-stage liver disease (MELD) score compared with the Child-Pugh classification.

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 6.4 months. Receiver-operating characteristic (ROC) analysis identified MELD score = 7.5 [area under the curve (AUC) 0.81] and Child-Pugh score = 6.5 (AUC 0.86) as the best cut-off values for predicting the incidence of complications over Common Terminology Criteria for Adverse Events grade 2. There was no significant difference in the discrimination power between the MELD score and the Child-Pugh score on comparison of the two ROC curves (p = 0.17). On multivariate analysis, age, MELD score and radiotherapy dose were significant prognostic factors for overall survival (p = 0.021, 0.038 and 0.006, respectively). In contrast, the Child-Pugh classification, tumour response, PVTT response and the number of prior interventional radiologic treatments were not significant on multivariate analysis. CONCLUSION: This study showed that the best MELD score cut-off value is 7.5 and that the MELD score is a better prognostic factor than the Child-Pugh classification in 3D CRT for HCC with PVTT. ADVANCES IN KNOWLEDGE: The MELD score is useful for predicting the risk of severe toxicities and the prognosis of patients treated with 3D CRT for PVTT.

Mid-term Results of Endovascular Treatment for Infrarenal Aortic Stenosis and Occlusion.

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. METHODS: This study includes 6 consecutive patients (3 men, 3 women; mean age, 59.3 years) with infrarenal aortic stenosis or occlusion who underwent endovascular intervention at our hospital between April 2009 and February 2014. All patients had bilateral intermittent claudication. The mean preoperative ankle-brachial index (ABI) showed a slight to moderate decrease: right 0.668 and left 0.636. The mean lesion site length was 12.5 mm, the percent stenosis was 90.7%, and calcification was present in 3 patients. Primary stenting was performed in all patients. The stent selected was generally a self-expanding stent (SES). For patients with severe calcification, the stent selected was a balloon-expandable stent (BES). RESULTS: Four patients received an SES and two patients received a BES. The technical success rate was 100%, no complications occurred, and the mean pressure gradient disappeared or decreased. Symptoms resolved in all patients and the postoperative ABI improved: right 0.923 and left 0.968. During a mean follow-up period of 27 months, there were no recurrent symptoms and no restenosis on CT angiography. CONCLUSIONS: Endovascular treatment should be considered as a first line treatment for focal infrarenal aortic stenosis and occlusion.

Combination radiofrequency ablation and local injection of the immunostimulant bacillus Calmette-Guérin induces antitumor immunity in the lung and at a distant VX2 tumor in a rabbit model.

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. Survival was evaluated with Kaplan-Meier method and log-rank test. Weekly mean volume and specific growth rate (SGR) of auricle tumors were calculated, and comparisons were made by Mann-Whitney test. RESULTS: Median survival of control, RF-only, and RF/BCG groups were 23, 41.5, and 103.5 days, respectively. Survival was significantly prolonged in the RF-only and RF/BCG groups compared with the control group (P = .034 and P =.003, respectively), but no significant difference was found between the RF-only and RF/BCG groups (P = .279). Only in the RF/BCG group was mean auricle tumor volume decreased 5 weeks after implantation. No significant difference in SGR was found between the control and RF-only groups (P = .959), but SGR in the RF/BCG group was significantly lower than in the control group (P = .005). CONCLUSIONS: The combination of RF ablation and local injection of BCG resulted in distant tumor suppression compared with the control group, whereas RF ablation alone did not produce this effect. Therefore, the combination of RF ablation and local injection of BCG may induce systemic antitumor immunity.

Effective palliative radiofrequency ablation for tumors causing pain, numbness and motor function disorders: case series.

BACKGROUND: We present a case series of a palliative radiofrequency ablation (RFA) for the tumors that lead to the resolution of pain and motor function disorders. RFA is widely used on tumors in various organs and often reported in good outcome. There are some reports that RFA was performed as a palliative treatment but a few reports of RFA that performed for lung tumor as a palliative treatment. This case series includes two cases, palliative RFA for a sacrum and a lung tumor. The results of this case series presented that a palliative RFA is effective in improving the symptoms of patients. CASE PRESENTATION: Case 1. A 64-year-old Japanese woman with a chordoma at her sacrum presented with pain in her left leg and claudication. Though operations, radiation therapy and GS-TAE (gelatin sponge-transarterial embolization, via the L5 lumbar artery) were performed, the size of the tumor leading pain and claudication increased. RFA was performed for the sacral tumor, and these symptoms resolved one year after the procedure. Case 2. A 68-year-old Japanese man with a leiomyosarcoma at the apex of left lung presented with pain and motor function disorders of the left upper limb. Dissemination in the pleura was appeared after the operation for a leiomyosarcoma at the mediastinum. Though radiation therapy and a second operation were performed, the tumor at the apex of the left lung increased and pain and numbness of the left upper limb were appeared after the second operation. RFA was performed for the left lung tumor, and the symptoms resolved 3 months after RFA. CONCLUSION: RFA is effective as a palliative treatment and has a potential to salvage the patients from the symptoms of the tumors when conventional palliative treatments such as surgery, radiation therapy, and chemotherapy are difficult or contraindicated.

Neointimal hyperplasia after stent placement across size-discrepant vessels in an animal study.

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. Angiography and intravascular ultrasound (IVUS) were performed immediately and after 1 and 3 months; histopathologic examinations were then performed. Furthermore, the chronic outward force (COF) on the same type of stent was investigated in vitro. RESULTS: On IVUS, thickened intima was seen on the EIA at 1 month (5.1 ± 4.2 mm(2)) and at 3 months (7.8 ± 2.5 mm(2)). For the aorta, thickening of the intima was negligible at any time. Histopathologically, the percentage of the vessel obliterated by NIH was significantly greater on the iliac side than on the aortic side (33.2 ± 10.4 vs. 13.4 ± 4.4 %). The COF exerted when stent diameter reached that of the EIA and the aorta was 0.73 and 0.17 N/mm(2), respectively. CONCLUSIONS: When a non-tapered stent is placed in vessels with a large discrepancy in diameter, attention must be paid to increased NIH in the oversized side.