81 research outputs found

    Satellite radiance data assimilation for binary tropical cyclone cases over the western North Pacific

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    A total of three binary tropical cyclone (TC) cases over the Western North Pacific are selected to investigate the effects of satellite radiance data assimilation on analyses and forecasts of binary TCs. Two parallel cycling experiments with a 6 h interval are performed for each binary TC case, and the difference between the two experiments is whether satellite radiance observations are assimilated. Satellite radiance observations are assimilated using the Weather Research and Forecasting Data Assimilation (WRFDA)'s three-dimensional variational (3D-Var) system, which includes the observation operator, quality control procedures, and bias correction algorithm for radiance observations. On average, radiance assimilation results in slight improvements of environmental fields and track forecasts of binary TC cases, but the detailed effects vary with the case. When there is no direct interaction between binary TCs, radiance assimilation leads to better depictions of environmental fields, and finally it results in improved track forecasts. However, positive effects of radiance assimilation on track forecasts can be reduced when there exists a direct interaction between binary TCs and intensities/structures of binary TCs are not represented well. An initialization method (e.g., dynamic initialization) combined with radiance assimilation and/or more advanced DA techniques (e.g., hybrid method) can be considered to overcome these limitations

    Surgical Management of Takayasu's Arteritis

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    The results of surgical bypass and endarterectomy in Takayasu's arteritis (TA) were reported to be poor compared to usual atherosclerosis patients. However, if ischemic symptoms due to occlusive disease were severe, surgical procedures were inevitable. We report surgical experience of 5 patients with TA. Five women (ranged from 26 to 58 yr) were operated between June 1998 and May 2004. Three patients showed occlusion of main branches of aortic arch and had symptoms of cerebral ischemia. One patient showed near total occlusion in the midabdominal aorta and had symptoms of orthopnea and uncontrolled hypertension. One patient showed total occlusion of abdominal aorta at the level of aortic bifurcation and had a symptom of severe claudication on both legs. Bypasses from the ascending aorta to the carotid artery were performed in 3 cases. Bypass from the thoracic aorta to the left common iliac artery was performed in one case and endarterectomy of abdominal aorta in one case. The ischemic symptoms related with arterial occlusion were resolved after surgery. And the symptoms of cardiac failure disappeared. The symptomatic TA frequently required arterial reconstruction. The symptomatic improvement and excellent mid-term patency could be expected after arterial reconstruction and endarterectomy

    A case of hepatocellular carcinoma in the caudate lobe successfully treated by transcatheter arterial chemoembolization using drug-eluting beads

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    Hepatocellular carcinoma (HCC) in the caudate lobe remains one of the most intricate locations where various treatments tend to pose problems with regard to the optimal approach. Surgical resection has been regarded as the most effective treatment; however, isolated resection of the caudate lobe is strenuous and associated with a high rate of early recurrence. Percutaneous ablation might be technically difficult or impossible to perform due to the deep location of tumors and adjacent large vessels. Treatment with drug-eluting beads (DEB) can potentially enhance the therapeutic efficacy for patients with unresectable HCC by drawing on the slower, more consistent drug delivery process. We described a case of a 62-year-old man with HCC in the caudate lobe who was successfully treated by DEB

    CASS (CyanoAcrylate closure versus Surgical Stripping for incompetent saphenous veins) study: a randomized controlled trial comparing clinical outcomes after cyanoacrylate closure and surgical stripping for the treatment of incompetent saphenous veins

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    Background Several modalities are used for the treatment of varicose veins. Open surgical treatment with ligation and stripping of the saphenous vein has been the standard of care for many years. Endovenous thermal ablation has been shown to be a safe and effective alternative with high, long-term, target-vein closure rates. Despite this, there is the possibility of thermal injury to surrounding structures. The recently introduced cyanoacrylate closure is also considered to be a good alternative and the risk of injury to surrounding structures is minimal. The purpose of this study is to demonstrate the non-inferiority of cyanoacrylate closure with the VenaSealℱ closure system compared to surgical stripping in terms of clinical outcomes for the treatment of incompetent great saphenous veins. Methods/design This is an open-label, multicenter, prospective, randomized controlled trial evaluating the non-inferior clinical outcomes of cyanoacrylate closure compared to surgical stripping for the treatment of incompetent saphenous veins. After baseline measurements, participants will be randomly allocated into either the cyanoacrylate closure group or the surgical-stripping group. The primary endpoint of the study is the complete closure rate of the target vein in the cyanoacrylate closure group, and the absence of venous reflux or residual venous tissue after surgical stripping in the surgical-stripping group. These endpoints will be measured by Doppler ultrasound performed by qualified vascular technologists or investigators at 3 months after treatment. Secondary outcomes include perioperative pain, postoperative ecchymosis, clinical assessment (including general and disease-specific quality of life evaluations), complete closure rate, and absence of venous reflux or residual venous tissue at the 12- and 24-month follow-ups, as well as all adverse event rates during the 24-month follow-up period. Discussion This multicenter randomized controlled trial is designed to show non-inferiority in terms of complete closure rate of cyanoacrylate compared to surgical stripping for the treatment of incompetent saphenous veins. Trial registration Clinical Research Information Service (CRIS), ID: KCT0003203. Registered on 20 September 2018.This is an investigator-sponsored study supported by a grant from Medtronic Korea Co., Ltd

    Incidence and Risk Factors of Iliac Artery Rupture during Aortoiliac Stenting

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    Purpose: Aortoiliac occlusive disease (AIOD) is widely prevalent and leads to severe claudication or chronic limb-threatening ischemia. Stent placement for AIOD demonstrated excellent outcomes in terms of long-term patency. However, iliac artery rupture is the most fearful complication during the aortoiliac stenting (AIS). This study aimed to evaluate the incidence and risk factors of iliac artery rupture during AIS. Materials and Methods: A retrospective review of consecutive patients with AIOD treated with AIS from 2009 to 2021 was completed. We excluded patients with instent restenosis. All types of stents, including self-expanding stent (SES), balloon-expandable stent (BES), or balloon-expandable covered stent (CS), were used. Angiographic characteristics and procedural outcomes were analyzed. Procedural success was defined as the residual stenosis <30%. Results: A total of 242 patients (86.8% male; mean age 68.8±10.0 years) with de novo AIOD were treated with AIS. The procedural success rate was 100%. Rupture occurred in six patients (2.5%) and all ruptures were occurred in the external iliac artery (EIA). Stenting of the EIA and less calcified lesion were risk factors for iliac rupture (P=0.028). All cases of iliac artery rupture were successfully treated with the CSs. Overall primary patency rates were 98.0% and 93.4% at 12 and 36 months, respectively. Primary patency rates of SES, BES, and CS were 87.7%, 88.4%, and 100% at 36 months, respectively. Conclusion: The incidence of iliac artery rupture during AIS was 2.5%. Stent placement in the less calcified lesion and EIA was a risk factor for rupture during AIS. Placement of the CS can be the straightforward solution in case of iliac artery rupture during AIS

    Prevalence and Risk Factors of Abdominal Aortic Aneurysms Detected with Ultrasound in Korea and Belgium

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    The objective was to investigate the prevalence of abdominal aortic aneurysms (AAAs) and the diameters of the aorta and common iliac arteries (CIAs) in a Korean cohort and secondly to analyze the differences in aortic diameter by comparison with a European cohort. The Korean cohort included participants ≄ 50 years who consented to AAA screening and data were analysed retrospectively. Aortic and common iliac diameters were measured using the outer-to-outer diameter method and prevalence rates were calculated. Common risk factors such as smoking, body mass index, pulmonary disease, hypertension, diabetes, hyperlipidaemia, ischaemic heart disease, and cerebrovascular disease were reported in association with AAA occurrence and AAA development. The aortic diameters were then compared with those in a Belgian cohort of 2487 participants identified in the LiĂšge AAA Screening Program. An aortic size index (ASI) was also calculated to account for the potential size differences in the Belgian and Korean populations. A total of 3124 Korean participants were examined using ultrasound. The prevalence of AAAs in this cohort was 0.7%. The combined prevalence of subaneurysmal dilatation and AAA was 1.5%. The prevalence in male smokers older than 65 years was 2.7% (19/715). The mean infrarenal aortic diameter was 17.3 ± 3.1 mm in men and 15.7 ± 2.7 mm in women; the corresponding values in Belgian participants were 19.4 ± 3.0 mm in men and 17.9 ± 2.4 mm in women. The median aortic size index was 0.99 (interquartile range 0.88–1.12). The mean infrarenal aortic diameter was significantly smaller in the Korean cohort than in the Belgian cohort. Considering the observed prevalence of AAAs in different age groups, the age groups which would contribute to most cases was male persons above 66 years in both cohorts
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