105 research outputs found
Exploring the boundaries of endovascular aneurysm repair:studying an all-comers population
No full textAn abdominal aortic aneurysm can be treated endovascularly since the early 1990s. In the endovascular technique, a stent is placed through the groin, which is less invasive than the open technique. An important limitation is that ruptured and complex aneurysms are less suitable and more long-term complications are seen. With the help of registration studies, this thesis investigated how stents function at the extremes of the manufacturers' instructions for use. The thesis shows that in the case of ruptured aneurysms, the technical results are good. Additionally, it is shown that in complex aneurysms the short-term number of complications is not unacceptable, despite the challenging anatomy. The long-term results will have to be determined in the future. The above results can contribute to determining the optimal treatment strategy of ruptured and complex aneurysms
Early outcomes with a single-sided access endovascular stent
No full textObjective: The objective of this study was to report the 1-year follow-up study results of the new Horizon stent graft (Endospan, Herzliya, Israel) from two different prospective consecutive trials. The Horizon abdominal aortic aneurysm stent graft system is a 14F profile system requiring only a single access site. It consists of three modules, introduced separately: base limb (iliac to iliac limb); distal aortic limb; and proximal aortic limb with a bare suprarenal crown and active fixation. Methods: Data from the first in man (FIM) clinical study with 10 patients enrolled and the pivotal study with 30 patients were analyzed. Outcomes measured were freedom from major adverse events (MAEs) including all-cause mortality, myocardial infarction, renal failure, respiratory failure, paraplegia, stroke, bowel ischemia, and procedural blood loss ≥1000 mL. Performance end points included successful delivery and deployment of the device, freedom from aneurysm growth ≥5 mm, type I or type III endoleak, stent graft occlusion, conversion to open surgery, rupture, and stent graft migration. Results: In the FIM study, one conversion to open surgery with >1000 mL of blood loss was registered perioperatively. In the pivotal study, no perioperative MAE was registered. Overall, at 1-year follow-up, two deaths and one aneurysm growth unrelated to endoleak were registered. Conclusions: The results of both the FIM and pivotal studies demonstrated that 39 of 40 procedures were successful for delivery and deployment of the Horizon stent graft. No MAE was registered during the follow-up. The primary safety and performance end points were met in both studies
A call for uniform reporting standards in studies assessing endovascular treatment for chronic ischaemia of lower limb arteries
No full textEndovascular therapy is a rapidly evolving field for the treatment of patients with peripheral arterial disease, and a magnitude of studies reporting on various modern revascularization concepts have been recently published. Thus, studies assessing the efficacy of endovascular therapy of peripheral arteries do not operate with uniformly defined endpoints, rendering a direct comparison of studies difficult. The purpose of this consensus statement is to highlight differences in the terminology used in the current literature and to propose some standardized criteria that must be considered when reporting results of endovascular revascularization for chronic ischaemia of lower limb arteries
Standardized definitions and clinical endpoints in carotid artery and supra-aortic trunk revascularization trials
No full textEndovascular therapy has emerged as a promising alternative to open surgery for stroke prevention in patients with obstructive disease of the supra-aortic arteries. Although most previous studies have used similar safety and efficacy endpoints, differences in definitions, timing of assessments, and standards of reporting have hampered direct comparisons across various trials
SBC2011-53463 IN VITRO THREE DIMENSIONAL IMAGING OF HUMAN CAROTID ATHEROSCLEROTIC PLAQUES USING ULTRASONOGRAPHY
No full textINTRODUCTION Ruptured atherosclerotic plaques in the carotid artery are the main cause of stroke (70-80%). To prevent it, carotid endarterectomy is the procedure of choice in patients with a recent symptomatic 70-99% stenosis. Today, the selection of candidates is based on stenosis size only. However, endarterectomy is beneficial for only 1 out of 6 patients [1], the patients with unstable plaques To determine the mechanical properties of healthy coronary arteries an in vitro model was developed by Van Den Broek et al. [2]. In this model an arterial segment can be fixed in a water bath, and a pressure pump induces a pulsatile pressure through the segment. By using ultrasonography (US), distension of the vessel wall can be visualized in 2D (ART.LAB, Esaote Europe, The Netherlands). With this in vitro model the pressure-diameter and pressure-axial force relation can be obtained. In this study, human atherosclerotic segments obtained from an endarterectomy procedure are used to determine the mechanical properties of the atherosclerotic components (local ethical committee approval was obtained for this study). The aim of this study is to adjust the existing set-up for use on atherosclerotic plaques and to design a tool for the conversion of 2D utrasound datasets to 3D data, to obtain the geometry of the artery including pressure and distension information over time. Eventually these datasets will be used as input for inverse numerical computations for the determination of mechanical properties of the plaques
Intravascular ultrasonography allows accurate assessment of abdominal aortic aneurysm: An in vitro validation study
No full textAbstractObjective: The objective of this study was to acquire insight into the interpretation of intravascular ultrasound images of the abdominal aorta and to assess to what extent this technique can provide useful parameters for the endovascular treatment of patients with abdominal aortic aneurysm. Study Design: This was a descriptive study. Methods: Fifteen abdominal aortic specimens (normal, atherosclerotic, or aneurysmal) were studied. Ultrasonic images and corresponding histologic sections were compared for vessel wall characteristics, lesion morphologic characteristics, and lumen diameter. The length of the aneurysm and the length of the proximal and distal neck were measured and compared with external measurements. Tomographic images were reconstructed to a three-dimensional format. Results: Normal aortic wall was seen as a two- or three-layered structure corresponding with intima, media, and adventitia. A distinction could be made among fibrous lesion, calcified lesion, and thrombus and between normal and aneurysmal aorta. Correlation between the histologic specimens and intravascular ultrasonography for lumen diameter measurements was high (r = 0.93; p < 0.001). In a similar fashion, correlation between external measurements and intravascular ultrasound measurements on the length of the aneurysm and its proximal and distal neck was high (r = 0.99; p < 0.001). Three-dimensional analysis enhanced interpretation of the tomographic images by visualizing the spatial position of anatomic structures and contributed to understanding the shape and dimensions of the aneurysm. Conclusions: Intravascular ultrasonography provides accurate information on the vessel wall, lesion morphologic characteristics, and quantitative parameters of the abdominal aorta. Spatial information supplied by three-dimensional analysis contributes to a more realistic interpretation of the tomographic images. (J Vasc Surg 1998;27:347-53.
Three-Dimensional Ultrasound Study of Carotid Arteries Before and After Endarterectomy
No full text
Background and Purpose
—It has been proved that symptomatic patients with severe carotid stenosis benefit from endarterectomy. Currently used methods for quantitation of the severity of carotid stenosis have limitations, and the impact of endarterectomy on the operated region of carotid artery remains unknown. The purpose of this study was to examine the accuracy of a 3-D ultrasound system for quantitation of stenotic lesions and to evaluate changes in regional vessel volume and cross-sectional area after carotid endarterectomy.
Methods
—We studied 14 patients with both carotid angiography and 3-D ultrasound. Of 13 patients who underwent surgery, 12 were reexamined with 3-D ultrasound after surgery. The length and volume of 20 randomly selected plaques were measured from 3-D data sets. The severity of stenosis was quantified by 3-D ultrasound using both a diameter method and an area method on cross-sectional views at the most stenotic site; the results were then compared with those from carotid angiography. The segmental vessel volume and average cross-sectional area of the operated artery both before and after endarterectomy were measured from 3-D ultrasound data.
Results
—Good correlation was obtained between 3-D ultrasound and carotid angiography in quantitative analysis of carotid stenosis (SEE=12.4%,
r
=0.76, and mean difference=7.0±12.3% with the diameter method; SEE=10.5%,
r
=0.82, and mean difference=1.8±10.5% with the area method by 3-D ultrasound). 3-D ultrasound had excellent reproducibility and small intraobserver and interobserver variability in plaque length and volume measurements. No significant changes in segmental vessel volume and average cross-sectional area of the operated artery were observed after surgery in patients with suture closure. However, a significant increase in segmental vessel volume was obtained in patients with polyfluorethylene patches applied to the surgical opening of the artery.
Conclusions
—3-D ultrasound can be used for both qualitative and quantitative analysis of plaques in the carotid artery and to detect and quantify significant carotid stenosis. Its volumetric potential has important clinical implications in serial follow-up studies for observing the progression or regression of stenotic lesions and for evaluating the outcome of interventional procedures such as endarterectomy or stent placement.
</jats:p
Systematic approach to ruptured abdominal aortic aneurysm in the endovascular era: Intention-to-treat eEVAR protocol
No full textEmergency endovascular aneurysm repair (eEVAR) for ruptured abdominal aortic aneurysms (rAAA) is still a relatively new treatment option. A pre-defined strategy of an eEVAR first approach for rAAA is associated with improved mortality rates. After establishing and implementing the Intention-to-treat eEVAR protocol for rAAAs the mortality and morbidity rates improved significantly. The presented Intention-to-treat eEVAR protocol starts at the first telephone call to the ambulance department and lasts until the post-operative care unit. The protocol involves the close collaboration between the ambulance department, vascular surgeon, emergency department physicians, anaesthesiologists, operating room staff and, radiology technicians. The availability of a variety of off-the-shelf stent-grafts, and an operating room that is adequately equipped to perform endovascular procedures is crucial in obtaining better outcomes. High volume centres that offer open surgical repair as well as eEVAR for rAAA show that the Intention-to-treat eEVAR protocol is achievable and appears to be associated with favorable mortality over open repair with appropriate case selection. Unstable or older patients with rAAA may particularly benefit by eEVAR
- …
