Fenestrated endovascular aneurysm repair (FEVAR) is a minimally invasive method of abdominal aortic aneurysm (AAA) repair utilized in patients with complex vessel anatomies. Stent grafts (SG) used in this process contain fenestrations within the device that need to be aligned with the visceral arteries upon successful SG deployment. Proper alignment is crucial to maintain blood flow to these arteries and avoid surgical complications. During fenestrated SG deployment, rotation of the SG can occur during the unsheathing process. This leads to misalignment of the vessels, and the fenestrations and is associated with poor clinical outcomes. The aim of this study was to develop a computational model of the FEVAR process to predict SG rotation. Six patient-specific cases are presented and compared with surgical case data. Realistic material properties, frictional effects, deployment methods, and boundary conditions are included in the model. A mean simulation error of 2鈥塪eg (range 1-4 deg) was observed. This model was then used to conduct a parameter study of frictional properties to see if rotation could be minimized. This study showed that increasing or decreasing the coefficients of friction (COF) between the sheath and the vessel walls would decrease the amount of rotation observed. Our model accurately predicts the amount of SG rotation observed during FEVAR and can be used as a preoperative planning tool within the surgical workflow.
Hemodynamics plays a critical role in the development of atherosclerosis, specifically in regions of curved vasculature such as bifurcations exhibiting irregular blood flow profiles. Carotid atherosclerotic disease can be intervened by stent implantation, but this may result in greater alterations to local blood flow and consequently further complications. This study demonstrates the use of a variant of Doppler optical coherence tomography (DOCT) known as split spectrum DOCT (ssDOCT) to evaluate hemodynamic patterns both before and after stent implantation in the bifurcation junction in the internal carotid artery (ICA). Computational fluid dynamics (CFD) models were constructed to simulate blood velocity profiles and compared to the findings achieved through ssDOCT images. Both methods demonstrated noticeable alterations in hemodynamic patterns following stent implantation, with features such as slow velocity regions at the neck of the bifurcation and recirculation zones at the stent struts. Strong correlation between CFD models and ssDOCT images demonstrate the potential of ssDOCT imaging in the optimization of stent implantation in the clinical setting.
reintervention had a greater renal stent distance (mean, 1.73 6 0.62 stents), as measured from the renal fenestration to the end of the stent, compared with those who did not need an additional renal procedure (2.84 6 0.96 cm vs 2.65 6 1.26 cm; P 录 .048). Other parameters including preoperative aortic diameter at the renal level, aortic stent graft diameter, and fenestration to renal ostium distance were similar between the two groups (P > .05).Conclusions: There is a trend observed for higher renal reintervention rates with a longer renal stent length. Other variables, such as preoperative aortic diameter, aortic stent graft size, and fenestration to renal ostium distance do not affect renal reinterventions.
Fig 2). Thirty-one different institutions purchased CMDs, with the absolute number of devices purchased per institution ranging from 3 to 194. Conclusions: The overall rates of both fenestrated and branched thoracoabdominal stent grafts have significantly increased between 2010 and 2016. Whereas this data set is limited to one manufacturer, it provides an important snapshot into the use of custom medical devices in advanced aortic repair in Canada.
BACKGROUND: In March 2020, COVID-19 assessment centres were launched across the province of Ontario to facilitate COVID-19 testing outside of emergency departments. We aimed to study the degree to which assessment centres provide education and follow-up care for patients with suspected COVID-19. METHODS: We conducted an online survey of Ontario COVID-19 assessment centre directors between September 15 and October 15, 2020. The primary outcomes studied were the types of educational modalities employed and information conveyed, methods and frequency of test result communication, and any follow-up care that was offered. Survey respondents were also asked to provide descriptions of barriers to patient education and test communication. RESULTS: A total of 56 directors (representing 73 assessment centres) completed the survey. The most frequent educational modalities employed were educational handouts (92%), direct in-person counselling (89%), and referral to website (72%). Seventy-one percent of respondents indicated patients with positive test results would be notified, and 61% of respondents indicated that follow-up care would be offered. The most frequently reported barriers to patient education were insufficient time and high volume of tests, while the most frequently reported barriers to communication of test results were difficulty accessing online health portals and high volume of tests. CONCLUSION: The ability of many assessment centres to provide patient education is limited by both individual patient and system-level factors. Assessment centres may benefit from standardization of educational materials, improved accessibility to test results for patients in marginalized groups, and virtual pathways to facilitate additional counselling and care for individuals who test positive.
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