1,721,007 research outputs found
Trattamento endovascolare della patologia dell'arco aortico
Full text linkIl miglior approccio per il trattamento delle patologie dell’arco dell’aorta rimane attualmente oggetto di dibattito non essendo ancora supportato da solide evidenze. La maggior parte dei dati relativi ai risultati post-operatori riguardo ai pazienti sottoposti ad interventi chirurgici per patologia dell’arco dell’aorta, si basa su un numero esiguo di casi, su trattamenti eterogenei e follow-up limitati. L’aorta ascendente e l’arco aortico costituiscono un segmento peculiare dell’aorta toracica per quanto riguarda l’anatomia, la fisiologia, la patologia e l’approccio terapeutico. La posizione anatomica all’interno del mediastino e la presenza delle principali branche arteriose responsabili della perfusione del cuore e dell’encefalo rendono conto delle forti difficoltà tecniche nell’approccio chirurgico a questa porzione dell’aorta, e delle importanti complicanze che possono associarsi a tali interventi. Per questo motivo la terapia chirurgica è spesso riservata solo ai pazienti in buone condizioni generali e con un rischio operatorio accettabile. Inoltre tale segmento vascolare riveste un ruolo particolare poiché rappresenta da sempre una ‘’zona di confine’’ tra la cardiochirurgia e la chirurgia vascolare, richiedendo pertanto una stretta collaborazione e sinergia tra diverse figure professionali quali il cardiochirurgo, il chirurgo vascolare, il cardio-anestesista, il cardiologo interventista, il radiologo interventista, il perfusionista e l’ecocardiografista, all’interno di strutture sanitarie attrezzate ed altamente specializzate, ovvero i cosiddetti ‘’centri di eccellenza”.
L’intervento di sostituzione dell’aorta ascendente fu eseguito per la prima volta a Houston nel 1952 da DeBakey e Cooley1, senza l’utilizzo della circolazione extracorporea. Gli stessi descrissero nel 1956 il primo caso di sostituzione dell’aorta ascendente in circolazione extracorporea (bypass cardio-polmonare)2, mentre solo nel 1957 riportarono i risultati favorevoli dell’intervento di sostituzione dell’arco aortico3. Il gruppo di Houston che faceva capo a questi due grandi chirurghi, giustamente considerati pioneri della chirurgia dell’aorta toracica, contribuì negli anni seguenti alla diffusione di tali tecniche chirurgiche verso il resto del globo. Durante i successivi cinquanta anni, lo sviluppo dell’imaging radiologico, il progresso delle tecniche chirurgiche ed anestesiologiche, nonchè l’avvento dei metodi di circolazione extracorporea e dei sistemi di protezione cerebrale, hanno permesso di trattare la maggior parte dei pazienti con un significativo miglioramento dei tassi di mortalità e morbilità, i quali tuttavia rimangono ancora oggi tra i più alti rispetto alla media degli interventi chirurgici. Per cercare di ridurre ulteriormente l’invasività e le complicanze perioperatorie della chirurgia dell’aorta ascendente e dell’arco aortico, nell’ultimo decennio, sono stati studiati e sviluppati approcci differenti, meno invasivi, che includessero l’utilizzo delle tecniche endovascolari maturate negli altri distretti aortici (aorta toracica discendente, toracoaddominale e addominale), adattando queste ultime alla particolare anatomia dell’arco. Queste procedure, riportate per la prima volta nel 1998,4 che possono combinare la chirurgia tradizionale con quella endovascolare (procedure ibride) o che possono utilizzare tecniche endovascolari complesse (ad esempio con l’utilizzo di endoprotesi ramificate, o con tecniche “chimney”), hanno dimostrato di poter ridurre sensibilmente la mortalità e la morbilità perioperatoria. Tuttavia, attualmente è prematuro trarre delle conclusioni sull’effettiva efficacia a lungo termine di tali procedure.
Obiettivo di questo studio è quello di valutare i risultati a medio termine delle procedure endovascolari a carico dell’arco aortico
Endovascular reconstruction of the aortic arch with new-generation dual-branch and triple-branch endograft: design, applicability, indications, outcomes, and future directions
No full textIntroduction: Repair of aortic arch pathologies such as degenerative aneurysms and dissections still represents a significant challenge for vascular and cardiac surgeons. We focused on the design, evolution, implementation, and prospects of endovascular dual branch technology for treatment of pathologies in the aortic arch. Areas covered: The literature search was conducted in a non-systematic fashion through the PubMed and Scopus databases; articles deemed relevant to the scope of the work and fully published in English language from January 12,000 until December 2023 were considered for inclusion. Two companies so far have developed and launched in market a dedicated arch dual branch platform: Terumo Aortic and Cook Medical. Expert opinion: A common limitation to the available technology is represented by the fact that urgent cases (i.e. large or rapidly growing aneurysms, symptomatic patients) cannot be treated because the customization process generally takes between 6 and 8 weeks, and there is an inherent risk for aorta-related adverse events to happen during the waiting time. While the future holds much promise, several technical hurdles still exist and further developments (in device design, operators' skills, patients' selection, and outcomes assessment) are needed to establish the safety and effectiveness of treatment particularly over the long-run
Endovascular repair of aortic arch disease with double inner branched thoracic stent graft: the Bolton perspective
No full textBACKGROUND: In the light of current evidence, endovascular repair of aortic arch pathologies with custom-made devices should be considered a valid alternative to decrease operative mortality and morbidity associated with open or hybrid repair. Today, two double inner branch devices are available on market. We report our single-center experience with Bolton double branch stent graft in the treatment of aortic arch disease.METHODS: Between 2013 and 2016, 15 high-risk patients with arch pathology were treated in our center with a custom-made branched device. Six of these received a Cook arch branched stent graft. Nine were treated with Bolton device. Among these, 2 with single branch model were excluded leaving a subgroup of 7 patients object of this study.RESULTS: Out of the 7 male patients (mean age 76, range 70-85) included in the study. 2 died in-hospital after stroke and retrograde dissection, respectively. No other death, major complication or secondary intervention was recorded at a mean follow-up of 24 (min-max 6-53) months. neither any aneurysmal diameter evolution nor branch related complications.CONCLUSIONS: Despite the small sample size, our results are in line with the early-published experiences about this technique. Endovascular repair of aortic arch disease with custom-made branched devices should always be considered to give high-risk patients a chance of repair
Endovascular arch replacement with a dual branched endoprosthesis
No full textBackground: In the light of current evidence, endovascular repair of aortic arch pathologies with custom-made devices should be considered a valid alternative to decrease operative mortality and morbidity associated with open or hybrid repair. Currently, two double inner branch devices are available on the market. Some papers from multicenter experiences have been published about the use of Cook device. We report our single-center experience with Bolton double branch stent graft in the treatment of aortic arch disease.Methods: Between 2013 and 2016, nine high-risk patients with arch pathology were treated in our center with a Bolton custom-made branched device. Among these, two with a single branch model were excluded, leaving a subgroup of seven patients of this study.Results: Out of the seven male patients (mean age, 76; range, 70-85) included in the study, two (28%) died perioperatively after stroke (14%) and retrograde dissection (14%), respectively. No other death, major complications, including aneurysmal diameter evolution and branch related complications, or secondary intervention was recorded at a mean follow up of 24 [6-53] months.Conclusions: Despite the small sample size, our results are in line with the early experiences published on this technique. Endovascular repair of aortic arch disease with custom-made branched devices should always be considered to give high-risk patients a chance of repair
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
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
A national cross-sectional survey on time-trends for endovascular repair of genetically-triggered aortic disease and connective tissue disorders over two decades
No full textBackground: By this survey, we aim to gain national-based information regarding trends in endovascular repair (ER) for the treatment of aortic disease in patients with genetically-triggered aortic disease (GTAD) and connective tissue disorder (CTD) over the last two decades. Methods: All Italian vascular surgery centers (N.=80) were invited to participate in an anonymous electronic cross-sectional survey on ER for GTAD/CTD. Results: Overall, 29 institutions completed the survey, thereby yielding a 36% response rate. The percentage of responding institutions rises to 64% if only regional hubs were considered (23/36). The median number of index procedures per center was 6.2, and a steady increase in the overall number of interventions over time was also noted. Most patients were males (73%) with a median age of 48 years. The most common endovascular procedure was TEVAR (N.=101), followed by F/BEVAR (N.=43) and EVAR (N.=37). The overall technical success rate was 83.4% while major adverse events and mortality at thirty days were reported at 18.2% and 9.9%, respectively. An additional 5.0% mortality rate was noted for an overall one-year mortality of 14.9%, while 3.7% of all treated patients were diagnosed with a type 1 endoleak. Conclusions: This national cross-sectional survey, investigating trends in ER of GTADs and CTDs over two decades, highlights a consistent increase in the use of endovascular techniques for their treatment. Early mortality was acceptably low, yet influenced by the urgency of presentation. At one-year follow-up, a 5% additional death rate was noted, and the reintervention rate remained below one in ten
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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