Risk Factor Analysis of Bird Beak Occurrence after Thoracic Endovascular Aortic Repair

ObjectivesThe aim was to analyze the role played by anatomy and stent graft in the incidence of incomplete apposition to aortic arch.MethodsBetween 2007 and 2014 data including available and suitable computed tomographic angiography (CTA) imaging of patients who had undergone thoracic endovascular aortic repair were reviewed. The study included 80 patients (65 men, 54 ± 21 years) treated for traumatic aortic rupture (n = 27), thoracic aortic aneurysm (n = 15), type B aortic dissection (n = 24), penetrating aortic ulcer (n = 5), intramural hematoma (n = 2), aorto-oesophageal fistula (n = 2), and aortic mural thrombus (n = 5). Pre- and post-operative CTA images were analyzed to characterize bird beak in terms of length and angle, and to calculate aortic angulation within a 30 mm range at the proximal deployment zone.ResultsBird beak configuration was detected in 46 patients (57%): mean stent protrusion length was 16 mm (range: 8–29 mm) and mean bird beak angle was 20° (range: 7–40°). The bird beak effect was significantly more frequent after traumatic aortic rupture treatment (p = .05) and in landing zone 2 (p = .01). No influence of either stent graft type or generation, or degree of oversizing was observed (p = .29, p = .28, p = .81 respectively). However, the mean aortic angle of patients with bird beak was higher in the Pro-form group than that in the Zenith TX2 group (62° vs. 48°, p = .13). Multivariate analysis identified the aortic angle of the deployment zone as the unique independent risk factor of malapposition (HR = 1.05, 95% CI 1–1.10, p = .005). The cutoff value of 51° was found to be predictive of bird beak occurrence with a sensitivity of 58% and a specificity of 85%.ConclusionsAssessment of proximal landing zone morphology to avoid deployment zones generating an aortic angle of over 50° can be recommended to improve aortic curvature apposition with the current available devices

Numerical model for in-vitro ultrasound stimulation of bone cells: a parametric study

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Residual type B aortic dissection FSI modeling

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Monitoring of in-vitro ultrasonic stimulation of cells by numerical modeling

International audienceUltrasound stimulation of living tissues is a promising technique that can be safely applied for regenerative treatments. However, the ultrasound-induced mechanotransduction is still not well understood because of the large number of parameters involved at different scales and their difficult experimental accessibility. In this context, in-vitro studies may help to gain insight into th

Morphological Analysis of Healthy Aortic Arch

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Risk Factor Analysis for the Mal-Positioning of Thoracic Aortic Stent ă Grafts

International audienceObjective: The present study aimed at quantifying mal-positioning during ă thoracic endovascular aortic repair and analysing the extent to which ă anatomical factors influence the exact stent graft positioning. ă Methods: A retrospective review was conducted of patients treated ă between 2007 and 2014 with a stent graft for whom proximal landing zones ă (LZ) could be precisely located by anatomical fixed landmarks, that is ă LZ 1, 2, or 3. The study included 66 patients (54 men; mean age 51 ă years, range 17-83 years) treated for traumatic aortic rupture (n = 27), ă type B aortic dissection (n = 21), thoracic aortic aneurysm (n = 8), ă penetrating aortic ulcer (n = 5), intramural hematoma (n = 1), and ă floating aortic thrombus (n = 4). Pharmacologic hemodynamic-control was ă systematically obtained during stent graft deployment. Pre- and ă post-operative computed tomographic angiography was reviewed to quantify ă the distance between planned and achieved LZ and to analyze different ă anatomical factors: iliac diameter, calcification degree, aortic ă angulation at the proximal deployment zone, and tortuosity index (TI). ă Results: Primary endoleak was noted in seven cases (10%): five type I ă (7%) and two type II (3%). Over a mean 35 month follow up (range 3-95 ă months), secondary endoleak was detected in two patients (3%), both ă type I, and stent graft migration was seen in three patients. ă Mal-positioning varied from 2 to 15 mm. A cutoff value of 11 mm was ă identified as an adverse event risk. Univariate analysis showed that TI ă and LZ were significantly associated with mal-positioning (p = .01, p = ă .04 respectively), and that aortic angulation tends to reach ă significance (p = .08). No influence of deployment mechanism (p = .50) ă or stent graft generation (p = .71) or access-related factors was ă observed. Multivariate analysis identified TI as the unique independent ă risk factor of mal-positioning (OR 241, 95% CI 1-6,149, p = .05). A TI ă >1.68 was optimal for inaccurate deployment prediction. ă Conclusion: TI calculation can be useful to anticipate difficulties ă during stent graft deployment and to reduce mal-positioning. (C) 2016 ă European Society for Vascular Surgery. Published by Elsevier Ltd. All ă rights reserved