| 1. |
- Brunkwall, J., et al.
(författare)
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Endovascular Repair of Acute Uncomplicated Aortic Type B Dissection Promotes Aortic Remodelling: 1 Year Results of the ADSORB Trial
- 2014
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1532-2165 .- 1078-5884. ; 48:3, s. 285-291
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Uncomplicated acute type B aortic dissection (AD) treated conservatively has a 10% 30-day mortality and up to 25% need intervention within 4 years. In complicated AD, stent grafts have been encouraging. The aim of the present prospective randomised trial was to compare best medical treatment (BMT) with BMT and Gore TAG stent graft in patients with uncomplicated AD. The primary endpoint was a combination of incomplete/no false lumen thrombosis, aortic dilatation, or aortic rupture at 1 year. Methods: The AD history had to be less than 14 days, and exclusion criteria were rupture, impending rupture, malperfusion. Of the 61 patients randomised, 80% were DeBakey type IIIB. Results: Thirty-one patients were randomised to the BMT group and 30 to the BMT+TAG group. Mean age was 63 years for both groups. The left subclavian artery was completely covered in 47% and in part in 17% of the cases. During the first 30 days, no deaths occurred in either group, but there were three crossovers from the BMT to the BMT TAG group, all due to progression of disease within 1 week. There were two withdrawals from the BMT+TAG group. At the 1-year follow up there had been another two failures in the BMT group: one malperfusion and one aneurysm formation (p = .056 for all). One death occurred in the BMT TAG group. For the overall endpoint BMT+TAG was significantly different from BMT only (p < .001). Incomplete false lumen thrombosis, was found in 13 (43%) of the TAG+BMT group and 30 (97%) of the BMT group (p < .001). The false lumen reduced in size in the BMT+TAG group (p < .001) whereas in the BMT group it increased. The true lumen increased in the BMT TAG (p < .001) whereas in the BMT group it remained unchanged. The overall transverse diameter was the same at the beginning and after 1 year in the BMT group (42.1 mm), but in the BMT+TAG it decreased (38.8 mm; p = .062). Conclusions: Uncomplicated AD can be safely treated with the Gore TAG device. Remodelling with thrombosis of the false lumen and reduction of its diameter is induced by the stent graft, but long term results are needed. (C) 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.
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| 2. |
- Avci, M., et al.
(författare)
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The use of endoanchors in repair EVAR cases to improve proximal endograft fixation
- 2012
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Ingår i: Journal of Cardiovascular Surgery. - 0021-9509. ; 53:4, s. 419-426
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Tidskriftsartikel (refereegranskat)abstract
- Aim. The aim of this paper was to evaluate short-term outcome of the use of endoanchors to secure the primary migrated endograft and additional extender cuffs to the aortic wall in patients with previous failed endovascular aortic aneurysm repair. Methods. Consecutive patients who needed proximal repair of a primary failed endograft due to migration (with or without type IA endoleaks) were treated with endoanchors, with or without additional extender cuffs. Data of this group were prospectively gathered in vascular referral centers that were early adopters of the endoanchor technique. Preprocedural and periprocedural data were prospectively gathered and retrospectively analyzed. Follow-up after endoanchor placement consisted of regular hospital visits, with computed tomography or duplex scanning at 1, 6, and 12 months. Results. From July 2010 to May 2011, 11 patients (8 men), mean age 77 years (range, 59-88 years), were treated with endoanchors for a failed primary endograft (2 Excluder endografts, 1 AneuRx endograft, and 8 Talent endografts) due to distal migration of the main body, with or without type IA endoleak. Revision consisted of using endoanchors to secure the body of the primary endograft to the aortic wall to avoid persistent migration. Most patients had additional proximal extender cuffs with suprarenal fixation, which were secured with endoanchors to the aortic wall and in some patients also to the primary endograft. A median of 6 endoanchors were implanted. All endoanchors were positioned correctly but one. One endoanchor dislodged but was successfully retrieved using an endovascular snare. During a mean follow-up of 10 months (range, 3-18 months) no endoanchor-related complications or renewed migration of the endografts occurred. Two patients underwent repeat intervention due to persistent type IA endoleak during follow-up. Conclusion. The use of endoanchors to secure migrated endografts to the aortic wall is safe and feasible and might help to overcome persistent migration of primary failed endografts. In combination with the use of sole extender cuffs the majority of proximal EVAR failures can be solved.
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| 3. |
- Verhoeven, E. L. G., et al.
(författare)
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Real-world Performance of the New C3 Gore Excluder Stent-Graft : 1-year Results from the European C3 Module of the Global Registry for Endovascular Aortic Treatment (GREAT)
- 2014
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884 .- 1532-2165. ; 48:2, s. 131-137
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The European C3 module of the Global Registry for Endovascular Aortic Treatment (GREAT) provides "real-world" outcomes for the new C3 Gore Excluder stent-graft, and evaluates the new deployment mechanism. This report presents the 1-year results from 400 patients enrolled in this registry. Methods: Between August 2010 and December 2012, 400 patients (86.8% male, mean age 73.9 +/- 7.8 years) from 13 European sites were enrolled in this registry. Patient demographics, treatment indication, case planning, operative details including repositioning and technical results, and clinical outcome were analyzed. Results: Technical success was achieved in 396/400 (99%) patients. Two patients needed intraoperative open conversion, one for iliac rupture, the second because the stent-graft was pulled down during a cross-over catheterization in an angulated anatomy. Two patients required an unplanned chimney renal stent to treat partial coverage of the left renal artery because of upward displacement of the stent-graft. Graft repositioning occurred in 192/399 (48.1%) patients, most frequently for level readjustment with regard to the renal arteries, and less commonly for contralateral gate reorientation. Final intended position of the stent-graft below the renal arteries was achieved in 96.2% of patients. Thirty-day mortality was two (0.5%) patients. Early reintervention (<= 30 days) was required in two (0.5%) patients. Mean follow-up duration was 15.9 +/- 8.8 months (range 0-37 months). Late reintervention (>30 days) was required in 26 (6.5%) patients. Estimated freedom from reintervention at 1 year was 95.2% (95% CI 92.3-97%), and at 2 years 91.5% (95% CI 86.8-94.5%). Estimated patient survival at 1 year was 96% (95% CI 93.3-97.6%) and at 2 years 90.6% (95% CI 85.6-93.9%). Conclusions: Early real-world experience shows that the new C3 delivery system offers advantages in terms of device repositioning resulting in high deployment accuracy. Longer follow-up is required to confirm that this high deployment accuracy results in improved long-term durability.
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| 4. |
- Bachoo, P., et al.
(författare)
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Early outcome of endovascular aneurysm repair in challenging aortic neck morphology based on experience from the GREAT C3 registry
- 2013
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Ingår i: Journal of Cardiovascular Surgery. - 0021-9509 .- 1827-191X. ; 54:5, s. 573-580
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Tidskriftsartikel (refereegranskat)abstract
- Aim. The aim of this paper was to evaluate early outcome of the GORE (R) EXCLUDER (R) AAA Endoprosthesis featuring C3 Delivery System in subjects with aortic neck anatomy outside IFU. Methods. Individual patient data prospectively collected over a 2 year period from the Global Registry for Endovascular Aortic Treatment (GREAT). For each subject a minimum data set was collected containing demographic, pre/intra- and postoperative variables. Main outcome measures were successful exclusion of the AAA and occurrence of any major endoleak at 1 month. In this study, outside IFU was defined as aortic neck length less than 15 mm and/or aortic neck angle greater than 60 degrees. Results. A total of 400 subjects, (86.6% male, mean age 73.9 years). Primary pathology was AAA in 94.2% with 98.2% undergoing EVAR as a primary procedure. Sixty-eight subjects underwent EVAR outside IFU (neck length <15 nun N.=32, neck angle >60 degrees N.=47 and neck length <15 nun and angle >60 degrees N.=11). The graft was successfully deployed within 5 nun of its intended location in 63 (94%) cases utilising a total of 33 repositioning episodes. Eight aortic cuffs were used, 5 to treat a type 1 endoleak. At 30 days we recorded 2 type 2 endoleaks both successfully treated and 1 type 1b also successfully treated. There were 2 deaths, one in each group. Conclusion. GORE (R) EXCLUDER (R) AAA Endoprosthesis featuring C3 Delivery System allows re-positioning to be performed safely in cases outside IFU. Repositioning is an effective operative manoeuvre and facilitates EVAR in challenging anatomy. Longer follow-up is required to evaluate the durability of these results at 30 days.
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| 5. |
- Beltman, B., et al.
(författare)
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Phosphate Release Upon Long- and Short -Term Flooding of Fen Meadows Depends on Land Use History and Soil pH
- 2014
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Ingår i: Wetlands (Wilmington, N.C.). - : Springer Netherlands. - 0277-5212 .- 1943-6246. ; 34:5, s. 989-1001
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Tidskriftsartikel (refereegranskat)abstract
- Flooding of acidified and desiccated fen meadows is a management approach for mitigating loss of plant species as well as a short-term measure to prevent flooding in urban areas. Studies have shown that flooding events can cause extreme P release from soils. We questioned whether the occurrence of this 'internal eutrophication' from flooding depended on fertilization history and soil pH. A greenhouse experiment with soil cores from Ireland (turloughs) and from the Netherlands, exposed to flooding for 216 days (long-term) showed a substantial P release for sites with a history of fertilizer use only. Short-term flooding (20-25 days) caused little P release in all soils. There was no correlation between P release and initial soil pH (range 4.1-7.1). All flooded soils showed a significant decline in sulfate and increased iron in the pore water upon flooding. Field trials applying short term flooding to sites differing in soil pH, average soil moisture and history of fertilizer application showed there was no overall effect of flooding on phosphate, nitrate, ammonium, iron concentrations and pH of pore water. Sulfate concentrations significantlyincreased. Hence, problematic phosphate release is only induced by long term flooding of fen meadows with a history of fertilization.
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| 6. |
- Janssen, P., et al.
(författare)
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On the role of minority carriers in the frequency dependence of organic magnetoresistance
- 2011
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Ingår i: Synthetic metals. - : Elsevier. - 0379-6779 .- 1879-3290. ; 161:7-8, s. 617-621
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Tidskriftsartikel (refereegranskat)abstract
- In this work we investigate the frequency dependence of organic magnetoresistance (OMAR) both in small molecule-based (Alq3) and polymer (PPV derivative) materials, and investigate its thickness dependence. For all devices, we observed a strong decrease in magnetoconductance (MC) with increasing frequency of the ac component of the applied magnetic field. Moreover, we observed a strong reduction of the cut-off frequencies for increasing film thickness. By means of admittance spectroscopy and device simulations, we show that the cut-off frequency is related to the inverse transit time of the minority charge carriers. These observations confirm the important role of minority carriers in OMAR, and show that changes in OMAR are not only due to microscopic mechanisms, but also device physics is of significant relevance. (C) 2011 Elsevier B.V. All rights reserved.
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| 7. |
- Verhoeven, L. M., et al.
(författare)
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A numerical and experimental study of Polycyclic Aromatic Hydrocarbons in a laminar diffusion flame
- 2013
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Ingår i: Proceedings of the Combustion Institute. - : Elsevier BV. - 1540-7489. ; 34, s. 1819-1826
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Tidskriftsartikel (refereegranskat)abstract
- During the process of biomass gasification tars are formed which exit the gasifier in vapor phase. Tar condensation creates problems like fouling and plugging of after-treatment, conversion and end-use equipment. Gasification tars consist mainly of Polycyclic Aromatic Hydrocarbons (PAHs). Former research has shown the possibilities and difficulties of tar conversion by partial combustion. Basic studies to investigate the oxidation of tars in non-premixed combustion processes are expected to give more insight in this problem. In this paper the ability of the flamelet-generated manifold (FGM) approach to numerically model multi-dimensional, laminar, non-premixed flames with the inclusion of PAH chemistry is investigated. Modeling detailed PAH chemistry requires the employment of large reaction mechanisms which lead to expensive numerical calculations. The application of a reduction technique like FGM leads to a considerable decrease (up to two orders) in the required computation time. A 1D numerical validation shows that the improvements achieved by implementing a varying Lewis number for the progress variable Y are significant for PAH species with a large Lewis number, such as C10H8. Considerable improvements are found near the flame front and on the fuel side of the flame. A comparison has been made of FGM results with qualitative Planar Laser Induced Fluorescence (PLIF) measurements. A laminar CH4/N-2-air co-flow flame has been doped with two dopants, benzene and toluene, at three different concentrations. A set of filters was used in order to qualitatively distinguish the small (1-2 rings) and large (3 or more rings) aromatic species. The results show that the model is able to capture the major flame characteristics typical for PAH formation in multi-dimensional laminar non-premixed flames. (C) 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
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