1,721,116 research outputs found
New-generation devices and adjunctive procedures are the key elements to expanding the indications for endovascular aneurysm repair
No full textEndurant ® stent graft: A new-generation device for complex endovascular aortic aneurysm repair
No full textEndurant ® stent graft is a new-generation device developed with the aim of expanding the indications for endovascular aortic aneurysm repair. The wide use of Endurant stent graft in clinical practice in Europe and in the rest of the world, and its first encouraging results in patients with complex aortic anatomy proves the fact that vascular surgeons are empowered by endovascular techniques to better serve the patient with abdominal aortic aneurysm; this supports the idea that the continuous development of the materials in the endovascular field could establish the disappearement of open vascular surgeons in favour of a new-generation vascular specialist. © 2012 Future Medicine Ltd
Long-term results of thoracic endovascular aortic repair using a low-profile stent-graft
No full textPurpose: To evaluate the long-term results associated with the Zenith Alpha thoracic stent-graft, which was designed to address challenging access vessel anatomy. Materials and Methods: A retrospective analysis was conducted of 44 consecutive patients (mean age 72.5±8.3 years; 25 men) treated in a single center between August 2010 and October 2014 with a minimum follow-up of 5 years in survivors. The Zenith Alpha thoracic stent-graft was used to treat thoracic aortic aneurysms (n=37), thoracoabdominal aortic aneurysm (n=5), or penetrating aortic ulcer (n=2). Ten patients (23%) were American Society of Anesthesiologists class IV, and 9 (20%) had nonelective procedures. Access vessel anatomy was demanding (mean minimum diameter 5.4 mm, tortuosity index 1.3). The primary endpoint at 5 years was ongoing clinical success (freedom from aneurysm-/procedure-related death, secondary intervention, type I or III endoleak, infection, thrombosis, aneurysm expansion, rupture, or conversion). Secondary endpoints were freedom from all-cause mortality, device migration, stent fractures, fabric erosions, endoleaks, neurological events, and access vessel complications. Results: The ongoing clinical success was 84% (37 of 44 patients) owing to 4 aneurysm-related deaths (9%), 3 type I or III endoleaks (1 in a deceased patient), and 1 aneurysm expansion without detectable endoleak. There were 3 access vessel complications (7%), and no postoperative neurological events. Migration was observed in 2 cases (5%). There were no stent fractures or fabric tears. Conclusion: Despite the alterations in stent-graft design and material to reduce profile, the Zenith Alpha thoracic stent-graft showed favorable long-term results even in multimorbid patients with demanding iliac anatomy
Endovascular Aortic Aneurysm Repair with the Endurant Stent-graft: Early and 1-year Results from a European Multicenter Experience
No full textPurpose: To assess preliminary results of the Endurant stent-graft, which was developed to treat patients with abdominal aortic aneurysms (AAAs) and challenging aortoiliac anatomy. Materials and Methods: From November 2007 to October 2008, 45 patients with AAAs were treated with the Endurant stent-graft in three European vascular centers. Thirty-eight of the 45 patients (84%) had a hostile anatomy of the proximal neck. Early (30 days), early midterm (6 months), and late midterm (1 year) results were analyzed in terms of technical success, clinical success, morbidity, and mortality. Results: Intraoperative immediate technical and clinical success was achieved in all cases. At completion angiography, a type II endoleak was detected in seven of the 45 patients (16%) and an iliac limb stenosis was diagnosed and successfully treated in five (11%). At discharge, computed tomography demonstrated a type I endoleak in one of the 45 patients (2.2%). At 30 days, a graft limb thrombosis was diagnosed (2.2%) and successfully treated. The 30-day overall technical and clinical success rates were 97.8% (44/45 cases) and 95.6% (43/45 cases), respectively. During follow-up (mean duration, 8 months; range, 5-16 months), the type I endoleak was successfully treated with an aortic extension. Estimated freedom from type I or III endoleak and repeat intervention at 1 year was 97.8% (44/45 cases) and 93.3% (42/45 cases), respectively. Conclusions: The initial experience shows that the Endurant stent-graft appears to be effective in endovascular repair of AAAs in patients with hostile aortoiliac anatomy. This graft permits a broader group of patients to be treated with endovascular aneurysm repair; however, further studies are needed to evaluate the long-term results. © 2010 SIR
Aortic endograft and bridging stent-graft remodeling after branched endovascular aortic repair
No full textObjectives: The results of branched endovascular repair of thoracoabdominal aneurysms are mainly dependent on durability of the graft used. The purpose of this study was to evaluate postoperative aortic main body and bridging stent-graft remodeling, and their impact on bridging stent-graft instability at one year. Methods: Computed tomoangiographies of 43 patients (43 aortic main body mated with 171 bridging stent-grafts) were analyzed before and after branched endovascular repair as well as after a follow-up of 12 months. Primary endpoint was aortic main body remodeling (migration >5 mm, shortening >5 mm, scoliosis >5° or lordosis >5°). Shortening was defined as a reduced length in the long axis, scoliosis as left-right curvature, and lordosis as antero-posterior curvature. Aortic main body remodeling, aneurysm sac changes, and bridging stent-graft tortuosity were evaluated to study their correlations and the impact on the bridging stent-graft instability. Results: At 12 months, aortic main body remodeling was observed in 72% of the cases, migration in 39.5% (mean 5.21 mm), shortening in 41.9% (mean 5.79 mm), scoliosis in 58.1%, (mean 10.10°), lordosis in 44.2% (mean 5.78°). Migration, shortening, and scoliosis were more frequent in patients with larger aneurysms (p =.005), while scoliosis was significantly more frequent in type II thoracoabdominal aneurysm (p =.019). Aortic main body remodeling was significantly associated to bridging stent-graft remodeling (r: 0.3–0.48). The bridging stent-graft instability rate was 9.3%. Despite a trend toward significance (p =.07), none of the evaluated aortic main body and bridging stent-graft changes were associated with bridging stent-graft instability at 12 months. Conclusions: Aortic main body remodeling is frequent especially in large and extended thoracoabdominal aneurysm aneurysms. Aortic main body and bridging stent-graft remodeling was significantly correlated. While these geometric changes had no significant impact on bridging stent-graft instability at one year, a close long-term follow-up after branched endovascular repair could predict bridging stent-graft failures
Preliminary clinical and radiologic outcome of matched patients with thoracoabdominal aortic aneurysms treated by low-profile vs standard profile branched aortic endografts
No full textBackground: Durability of low-profile branched aortic stent-grafts (LPSG) in the treatment of patients with thoracoabdominal aortic aneurysms (TAAA) remains unclear. Objective of this study is to compare the outcomes of LPSG with standard profile branched aortic stent-grafts (SPSG). Methods: Between January 2016 and January 2020, 225 consecutive patients with TAAA were treated by branched endovascular aortic repair (BEVAR). Twenty-four patients who were treated with a LPSG were compared to 24 patients who received SPSG as a control group. Control patients were selected according to aneurysm size (maximum aneurysm diameter) and extension (Crawford classification) as well as availability of adequate preoperative and postoperative CT-angiograms at 24 months. The primary endpoint was ongoing clinical success defined as successful implantation and freedom from aneurysm- or procedure-related death, secondary intervention, type I or III endoleak, infection, thrombosis, aneurysm expansion or rupture and conversion. Secondary endpoints were radiological changes of the branched endograft (migration, shortening, scoliosis, lordosis, and fracture). Results: After a median follow-up of 22.6 (LPSG) and 26.2 months (SPSG), no significant difference was found in terms of technical success (100% in both groups), late mortality (4.2% vs 0%), aneurysm diameter increase (4.2% in both groups) and reinterventions (25% vs 37.5%). Infection, thrombosis, aneurysm expansion or rupture and conversion were not observed. Radiological analysis of aortic graft remodeling showed no fracture and no significant migration, shortening, scoliosis and lordosis of the LPSG (6.1 mm, 7.5 mm, 12.8° and 6.1°) compared to SPSG (3.9 mm, 5.1 mm, 7.9° and 5.6°) after 2 years. Conclusion: The clinical and radiological findings of the present study showed no increased mortality and complications for the matched patients who underwent treatment with low-profile vs standard-profile BEVAR. This study provides preliminary evidence of safety and efficacy of low-profile branched endografts in patients with demanding iliac access vessels
The role of block shape and slenderness in the preliminary estimation of rockfall propagation
Full text linkAmong the wide range of variables that influence the falling process of blocks during a rockfall event, the shape of the block often plays a crucial role. Spherical-like blocks typically reach longer runout distances while elongated and plate volumes stop earlier. Nevertheless, with reference to runout modelling and hazard analyses, the shape of the block was disregarded for very long time until the last two decades when more rigorous rockfall models were developed. Nowadays fully 3D rigid body models and particle-based ones can take into account different and complex aspects related to block geometry and size (e.g. shape, change of shape, slenderness, fragmentation, etc.) when in site-specific applications are addressed. On the other hand, when the rockfall analysis is extended over large areas, simplified runout models can be used for preliminary, quick analyses, aimed at highlighting the most critical zones of the area. In this case, the variables that influence the rockfall process should be included in the analysis in equivalent terms. Among these simplified models, the Cone Method allows to reduce the runout phase to an equivalent sliding motion of the block along an inclined plane. The inclination of this plane with respect to the horizontal plane (i.e. the energy angle ) can be related to both block and slope properties of the real rockfall case. The authors of this paper developed a methodology for the estimation of the energy angle as a function of the condition of the site under analysis (characteristics of the blocks and the slope), to be used for preliminary forecasting analyses at medium-small scales. To this aim, a series of parametric analyses have been carried out to quantify the role of each variable on the energy angle. In this paper, the role of block shape and slenderness (i.e. the ratio between the height and the width of the rock block) is analysed via several propagation analyses carried out on simplified synthetic slopes by using the fully 3D RAMMS::ROCKFALL model. The results were finally statistically treated in terms of energy angles in order to take into account the variability of rockfall trajectories and provide a contribution for the estimation of the parameters within preliminary analyses based on the Cone Method
Endurant Stent Graft: A new-generation device for a new generation of vascular specialist - Commentary
No full textIncoterms® e pluralità di metodi di regolamentazione dei contratti commerciali internazionali
No full textL’edizione 2010 degli Incoterms® della Camera di commercio internazionale offre lo spunto per interrogarsi sul ruolo svolto da questo strumento, che si affianca ad altre norme aventi per oggetto la regolamentazione di contratti internazionali e che si caratterizzano per l’eterogeneità delle fonti e per il ricorso ad una pluralità di metodi.
Lo studio analizza innanzitutto i metodi cui viene fatto ricorso per determinare la legge applicabile ai contratti del commercio internazionale; approfondisce poi il ruolo delle norme materiali uniformi e l’attività di armonizzazione del diritto dei contratti internazionali, il cui coordinamento consente la specificazione e la flessibilizzazione del diritto applicabile e ne promuove l’aggiornamento. Particolare rilievo viene prestato al ruolo svolto dagli Incoterms, che offrono alle parti ad un contratto la possibilità di fare ricorso a formule che identificano in modo rapido e sicuro alcuni aspetti rilevanti della transazione, ottenendo così vantaggi di speditezza, particolarmente utili quando le parti si trovano lontane, superando le eventuali frontiere linguistiche e rafforzando la certezza dell’operazione commerciale. Proprio perché sono le parti stesse a scegliere il contenuto degli obblighi rispettivi e ad identificare il termine che più è congeniale alle loro esigenze, vi è un rispetto della loro autonomia ed un elevatissimo grado di flessibilità, che consente di adeguare lo strumento alle specificità di ogni rapporto commerciale.
Gli Incoterms svolgono anche una rilevante funzione di armonizzazione, poiché ognuno dei termini costituisce una codificazione degli usi di un tipo contrattuale, nel quale vengono incorporate le clausole più diffuse nella prassi, concorrendo ad arricchire il diritto del commercio internazionale di modelli uniformi, facilmente riconoscibili e dotati di particolare autorevolezza, perché elaborati in seno ad un’organizzazione nota per la sua particolare competenza, associata alla notorietà e considerazione di cui gode la Corte internazionale di arbitrato istituita nel suo seno, seppure operante come organismo autonomo.
Viene così messa in luce la complementarietà fra le diverse norme che, utilizzando metodi diversi, compongono il vasto puzzle del diritto dei contratti del commercio internazionale. Con particolare riferimento alla vendita internazionale, gli Incoterms sono chiamati a coordinarsi in particolare con la Convenzione di Vienna: se essi sono stati richiamati dalle parti nel contratto, prevalgono su ogni disposizione contraria della Convenzione. D’altra parte, a meno che le parti non abbiano espressamente convenuto della loro inapplicabilità, nel commercio internazionale gli usi «largamente conosciuti e regolarmente osservati» sono richiamati dall’art. 9, che contiene una definizione che si adatta perfettamente a quelli fra gli Incoterms che hanno acquisito la notorietà e la stabilità sufficienti. La Convenzione di Vienna diviene così il veicolo che permette alle formule contrattuali tipizzate dalla CCI di rafforzare la propria applicabilità; gli operatori del commercio internazionale, sancendo la larga conoscenza e la regolare osservanza degli usi richiamati dall’art. 9 della Convenzione, hanno il compito di permetterle di svolgere al meglio questa funzione
The PROTAGORAS 2.0 study to identify sizing and planning predictors for optimal outcomes in abdominal chimney endovascular procedures
No full textObjective: The aim was to identify predictors of adequate pre-operative sizing and planning for chimney endovascular aortic repair (ChEVAR) in order to reduce the incidence of persistent type Ia endoleaks (IaELs) without influencing chimney graft (CG) patency. Methods: Consecutive patients who underwent ChEVAR between January 2009 and December 2017 at a single centre were evaluated retrospectively. Included were patients treated with one device combination (Medtronic Endurant mated with Getinge Advanta V12/iCast) and placement of single or double CG. The freedom from IaEL related re-interventions and primary CG patency was estimated by measuring aortic stent graft oversizing (OS), total neck length (TNL), and a composite parameter (L-OS: TNL [mm] + OS [%]). Results: Seventy-three patients who underwent placement of 101 CGs (45 single, 28 double) met the inclusion criteria. The median radiological follow up was 25.5 (interquartile range [IQR] 12–48) months. Freedom from IaEL related re-intervention was achieved in 94.6% with a median OS of 38.5% (IQR 30%–44%, p = .004), TNL 19 mm (16–25 mm, p = .62), and L-OS 59 (51–65, p = .018). Primary CG patency was achieved in 95% of the cases with a median OS of 36% (29%–42%, p = .008), TNL 19 mm (15.5–26 mm, p = .91), and L-OS 57 (50–64, p = .005). By using the receiver operating characteristic curve, an optimal cut off to prevent IaEL related re-interventions was identified by an OS of 30% (p < .001; L-OS 55, p = .006) and to avoid CG stenosis/occlusions by OS 42% (p < .001; L-OS 65, p < .001). In multivariable analysis, aortic endograft OS was the only independent parameter preventive for IaEL related re-intervention (odds ratio, 0.78; 95% confidence interval, 0.61–0.99). Conclusion: With the Endurant-Advanta V12/iCast combination, an aortic stent graft OS of at least 30% (range 30%–42%) should be used to avoid type Ia endoleaks and likewise to ensure CG patency
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