1,720,963 research outputs found
Pulmonary embolism due to popliteal vein aneurysm: Approach and surgical treatment - a case report
No full textA double nellix and chimney covered stents: challenging treatment of pararenal aortic aneurysm
Full text linkA 77-year-old male patient presented with a symptomatic, 66-mm pararenal aortic aneurysm. The patient was classified as unsuitable for open surgery due to significant comorbidities. Fenestrated or branched endografts were contraindicated due to the poor iliac access (6 mm diameter). A double Nellix with chimney endovascular aneurysm sealing (ChEVAS) technique was selected to exclude the pararenal aortic aneurysm and to preserve renal arteries and the superior mesenteric artery. Technical preplanning considered the ideal proximal landing zone to be close to the origin of the almost occluded celiac trunk and the distal common iliac arteries as the ideal distal landing zone. The total length of the aorta to cover was estimated as >180 mm, requiring 2 aortic EVAS systems, bilaterally overlapped. Technical success was achieved, and the patient was discharged on postoperative day 8 in good general condition. Successful aneurysm exclusion and target vessel patency without endoleak or stent-graft kinking or migration were confirmed at angio-computed tomography at 6 months
Hemodynamic Changes in Chevalier Eversion Versus Conventional Carotid Endarterectomy
No full textObjectivesThe eversion carotid endartectomy (E-CEA), mainly performed by means of Vanmaele technique, has been associated with loss of the baroreceptor reflex and postoperative hypertension.The purpose of this paper is to determine whether the eversion endarterectomy performed by means of Chevalier technique (C-CEA) modifies the function and the efficiency of baroreceptors, leading to lower postoperative hemodynamic change.MethodsA retrospective review of 380 patients who underwent carotid endarterectomy (120 Chevalier-CEA; 260 Standard-CEA) from December 2002 to November 2012 has been performed. The changes of blood pressure baseline during the postoperative course in C-CEA and S-CEA group were analysed and compared. Postoperative hypertension was defined as an elevation of systolic pressure >180 mm Hg or >40% rise above baseline.ResultsThe patients with Chevalier eversion technique did not develop a significantly higher blood pressure in the postoperative course compared to those operated with the standard technique. In the recovery room, the mean systolic blood pressure was 134 ± 21.9 mm Hg in C-CEA group versus 132 ± 24.6 mm Hg in S-CEA group. In the first postoperative day it was 132 ± 17.2 mm Hg in C-CEA versus 133 ± 17.4 mm Hg in S-CEA group.During the first six hours in the recovery room, the need for intravenous antihypertensive drugs was similar in the two groups. Fourteen patients in C-CEA group (11%) and thirty patients (11.5%) in the S-CEA group required vasodilators, without any significant difference (p = 1). The dosage of current preoperative antihypertensive therapy was increased in six patients (4.9%) of C-CEA group and in twelve patients (4.9%) of S-CEA group, without significant difference (p = 1).ConclusionsC-CEA has the same rate of postoperative hypertension of standard-CEA, which is probably related to the sparing of baroreceptor apparatus, compared to standard E-CEA. The Chevalier procedure could represent an E-CEA technique with its inherent advantages, without penalties related to postoperative hypertension, commonly observed after E-CEA
Morphofunctional characterization of a rare extracranial carotid artery giant aneurism
No full textAneurisms of the extracranial tract of the internal carotid artery (EICAA) are extremely rare, accounting for 0,4% to 2% of all carotid procedures (El-Sabrout et al., 2000); in females incidence is 2-11 times lower than in males (Siablis et al., 2004). A giant EICAA (32 x 35 mm) at C3 level was studied in a woman aged 81. Samples were prepared for standard transmission electron microscopy. Semithin sections were stained according to Relucenti et al. (2010). Ultrathin sections were contrasted with uranyl acetate and lead citrate. Images revealed the presence of many microvessels just beneath the tunica intima. They were patent, often showed sprouts and pericytes. Endothelial cells appeared metabolically active, with euchromatin, nucleoli, membrane blebs and junctional complexes. Their basal membrane was thickened and sometimes multilaminated. Leukocytes adhering to the endothelium were observed. The internal elastic lamina was so fragmented that it was very difficult to recognize it. The tunica media showed vascular smooth muscle cells (VSMCs) arranged in bundles encircled by collagen-rich extracellular matrix (EM), as well as scattered in the EM. VSMCs had perinuclear organelles, dense bands and caveolae. Collagen fibrils were arranged in a twisted or coiled fashion. Elongated fibroblasts were scattered among VSMCs. The external elastic lamina was conserved. Literature on EICAA is almost exclusively clinical, so this morphofunctional study elucidates structural and ultrastructural changes in the aneurism wall that can contribute to the knowledge of aneurism etiopathogenesis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The role of the profundoplasty in the modern management of patient with peripheral vascular disease
No full textBACKGROUND:
The occlusion of superficial femoris artery (SFA) is a common feature in peripheral vascular disease, so the profunda femoris artery (PFA) is a crucial collateral pathway for the perfusion of the lower limb. The purpose of this study is to discuss the safety, clinical, and hemodynamic efficacy of profundoplasty on the basis of limb salvage, patency, and freedom from reintervention rates. Furthermore, this study aims to identify the risk factors linked to the failure of the procedure.
METHODS:
The study is based on a retrospective analysis of prospectively collected data of identified patients who underwent profundoplasty from March 2005 to October 2015. All patients showed a hemodynamic stenosis, extended from the posterior wall of the common femoral artery (CFA) into the origin of the PFA and concomitant occlusion of SFA. Endarterectomy with patch angioplasty was performed in all cases. In patients with concomitant iliac occlusive disease, a hybrid treatment was carried out to restore an adequate inflow through an endovascular approach.
RESULTS:
Seventy-four profundoplasty were performed during the study period. Isolate profundoplasty was performed in 56 cases (75.7%), while in the remaining 18 cases (24.3%), concomitant endovascular treatment of iliac lesions was performed. Hemodynamic success was achieved in 90.5% of the cases. The mean ankle-brachial index significantly improved, rising from 0.36 ± 0.17 preoperatively to 0.57 ± 0.20 postoperatively (P < 0.001). The median follow-up period was 33 months. Primary patency rate was 98.5% at 12, 36, and 60 months. Freedom from reintervention rate was 97% at 1 year and 95.3% at 3 and 5 years. Limb salvage rate was 96.9% at 1 year and 92.7% at 3 and 5 years. Survival rates were 86%, 60%, and 47.4% at 1, 3, and 5 years, respectively. Multivariate analysis identified Rutherford class 5 or 6 lesions as the strongest predictors of major amputation or reintervention (odds ratio, 9.37; confidence interval: 0.98-89.27; P = 0.05).
CONCLUSIONS:
Profundoplasty is a durable, safe, and effective procedure in terms of clinical and hemodynamic results for patients characterized by occlusion of SFA and stenosis of CFA extended to profunda ostium. For patients with Rutherford category 5 and 6 ischemia, the only profundoplasty does not seem to be adequate, and concomitant distal bypass should be necessary to improve limb salvage and decrease reintervention rate
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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