[Show abstract][Hide abstract] ABSTRACT: To compare postoperative morphological and rheological conditions after eversion carotid endarterectomy versus conventional carotid endarterectomy using computational fluid dynamics.
[Show abstract][Hide abstract] ABSTRACT: Objective
The objective of this study was to review the current anatomic indications for and early results of aortouni-iliac (AUI) devices for endovascular aneurysm repair.
A total of 128 patients receiving an Endurant (Medtronic Inc, Minneapolis, Minn) AUI device in the U.S. Investigational Device Exemption trial (44 patients) or the Endurant Stent Graft Natural Selection Global Postmarket Registry (84 patients) were reviewed. Preoperative computed tomography imaging of patients in the Investigational Device Exemption trial and case report forms of Registry patients were used to determine anatomic indications. Baseline characteristics and early results were compared with those of 1305 patients receiving a bifurcated (BIF) device in sister studies.
The indication for the AUI device was unclear from case report forms in two Registry cases. The remaining 126 patients had a unilateral iliac occlusion in 30 (23%), a severely narrowed aortic segment in 58 (45%), severe iliac occlusive disease in 28 (22%), severe iliac tortuosity in 29 (23%), or complex iliac aneurysms in 19 (15%). Two patients had a previous aortobifemoral graft; 38 patients (30%) had multiple indications. The AUI cohort included more women than the BIF group did (19% vs 10%; P < .01) and had more severe comorbidities. Successful deployment was achieved in all AUI cases. The 30-day mortality was 2% (BIF cohort, 1%; P = .21). More AUI patients underwent repair under general anesthesia (81% vs 64%; P < .01), and procedures were longer (110.9 ± 54.9 minutes vs 99.2 ± 44.3 minutes; P = .02). Except for longer intensive care unit stays (19.6 ± 80.0 hours vs 9.0 ± 34.8 hours; P = .01) and higher myocardial infarction rates (4% vs 1%; P < .01), outcomes of the AUI cohort were similar to those of the BIF cohort. There were no migrations, ruptures, fractures, or open conversions at up to 1-year follow-up.
The AUI configuration extends endovascular aneurysm repair feasibility to several hostile anatomic conditions. Despite increased comorbidities in the recipient patient population and associated higher rates of postoperative myocardial infarction and respiratory complications, early outcomes with the new generation of AUI devices are acceptable and comparable to those after treatment with BIF configurations.
Journal of Vascular Surgery 10/2014; · 2.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Current commercially available modular stentgrafts are associated with relevant reintervention rates during follow-up. The Nellix Endovascular Aneurysm Sealing (EVAS) System is a potential device to overcome these limitations of EVAR. Device implantations outside of manufacturer instructions for use due to challenging neck anatomies are very common. This article presents very early experience in the treatment of patients with post EVAR complications and challenging neck anatomies.
The Journal of cardiovascular surgery. 10/2014; 55(5):601-12.
[Show abstract][Hide abstract] ABSTRACT: Background: Recently used endografts for envascular aneurysm repair (EVAR) exclude the pathology by fixation at both the proximal and distal landing zone. Due to endoleaks and migration EVAR is associated with a relevant rate of secondary interventions. The Nellix® system (Endologix Inc., CA, USA) was developed to seal the complete aneurysm using a polymer filling, therefore stabilising endograft-position and reducing the rate of endoleaks and reinterventions. The present contribution introduces the method, describes the technique of implantation and presents the first clinical results. Material und Methods: The Nellix system consists of two balloon-expandable stent grafts made of a cobalt-chromium composition, surrounded with ePTFE and the so-called endobags. During the implantation each endobag is filled with a non-biodegradable polymer, sealing the aneurysm lumina including the proximal and distal landing zone. Hence, lumbar arteries will be sealed to reduce the probability of a type II endoleak. Results: Longterm durability as well as the structural integrity of the Nellix system has been proven over 4 years in sheep experiments. The technical success in a multicentre, prospective registry was 94 % without the appearance of severe adverse events (migration, occlusion, secondary endoleak). Conclusion: EVAS is a new and different concept of endovascular AAA repair. Recent clinical data of the Nellix system are promising showing a high technical success rate while the need for secondary intervention is low. Further studies in larger cohorts are needed.
Zentralblatt für Chirurgie 10/2014; 139(5):e25. · 0.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Congenital malformations, tumors and aortic infections are rare and mostly asymptomatic. Unspecific clinical symptoms may cause delayed verification of the underlying disease. Contrast enhanced computer tomography- and magnetic resonance angiography are important sectional imaging methods for diagnostic completion. Consistent guidelines concerning diagnosis and therapy of rare aortic diseases are non-existent. Aortic tumors must be resected by open surgery, aortic infections in general require medical treatment and anomalies, if indicated, are treated more and more by endovascular or hybrid procedures. Therefore, it is recommended to treat these entities in an interdisciplinary approach in specialized aortic centers.
[Show abstract][Hide abstract] 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.
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.
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).
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.
Journal of Vascular Surgery 09/2014; · 2.98 Impact Factor
[Show abstract][Hide abstract] 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.
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.
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%).
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.
European Journal of Vascular and Endovascular Surgery 08/2014; · 3.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose : To evaluate a finite element analysis (FEA) model as a predictive tool for abdominal aortic aneurysm (AAA) rupture risk assessment. Methods : FEA of asymptomatic infrarenal AAAs in 15 men (mean age 72 years) was performed preoperatively using semiautomatic finite element analysis software (A4clinics) to calculate peak wall stress (PWS) and regions of highest and lowest rupture risk index (RRI). The areas of high and low RRI identified on the preoperative FEA were sampled during open surgery; aortic wall specimens were prepared for histological analysis. A semiquantitative score compared the histological findings from high and low rupture risk samples. Results : Significant correlation was found between histological AAA wall integrity and RRI in individual patients. AAA wall regions with highest RRI showed advanced histological disintegrity compared to regions with lower RRI within the same AAA: mean smooth muscle cells: 0.43 vs. 1.21, respectively (p=0.031); elastic fibers: 0.57 vs. 1.29, respectively (p=0.008); cholesterol plaque: 2.60 vs. 2.20, respectively (p=0.034); and calcified plaque: 2.27 vs. 1.40, respectively (p=0.017). The amount of calcified plaque was significantly correlated with PWS (r=0.528, p=0.043) by univariate regression analysis. However, there was no correlation between PWS or RRI and the histological findings between patients. Conclusion : These preliminary results show that high rupture risk regions estimated by FEA contain increased histopathological degeneration compared to low rupture risk samples within the same AAA. Until now, the role of FEA in predicting individual AAA rupture risk has not been established as a validated diagnostic tool. However, these data provide promising results for FEA model verification.
Journal of Endovascular Therapy 08/2014; 21(4):556-564. · 3.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The value of prophylactic atropine use during carotid artery stenting (CAS) in primary carotid stenosis to prevent procedural hemodynamic depression is well accepted. However, its impact in case of recurrent stenosis after eversion carotid endarterectomy (E-CEA), which is known to be associated with decreased baroreflex function due to discontinuation of the carotid sinus nerve, has not been investigated so far.
Journal of Vascular Surgery 07/2014; · 2.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To prove superiority of blood pool contrast agent gadofosveset over conventional contrast agent gadobenate dimeglumine for assessment of stenotic internal carotid artery (ICA).
Journal of Neuroradiology 07/2014; · 1.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Age and gender are two factors that determine the risk of atherosclerosis. The latter effect is only partly understood. Dicarbonyls, in particular methylglyoxal, participate in the development of atherosclerosis, and their major detoxification route is the enzyme glyoxalase 1 (GLO1), which is known to decrease during aging.
GLO1 expression and activity were studied in atherosclerotic carotid artery lesions of 71 patients with respect to demographic and clinical characteristics.
GLO1 activity was nonsignificantly reduced by >50% in individuals with carotid artery disease compared with control individuals. There was no significant difference in GLO1 expression between the groups; however, the GLO1 activity-to-protein ratio showed a significant reduction for the carotid artery disease patients compared with the controls. The reduction in the GLO1 activity-to-protein ratio was more pronounced in men and was associated with increased inflammation shown by a significant elevation in the expression-level of interleukin-1β.
These data suggest that GLO1 is regulated on the post-translational level by factors such as gender as well as factors that affect the overall burden of atherosclerosis.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 04/2014; · 2.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Native-MR angiography (N-MRA) is considered an imaging alternative to contrast enhanced MR angiography (CE-MRA) for patients with renal insufficiency. Lower intraluminal contrast in N-MRA often leads to failure of the segmentation process in commercial algorithms. This study introduces an in-house 3D model-based segmentation approach used to compare both sequences by automatic 3D lumen segmentation, allowing for evaluation of differences of aortic lumen diameters as well as differences in length comparing both acquisition techniques at every possible location.
Sixteen healthy volunteers underwent 1.5-T-MR Angiography (MRA). For each volunteer, two different MR sequences were performed, CE-MRA: gradient echo Turbo FLASH sequence and N-MRA: respiratory-and-cardiac-gated, T2-weighted 3D SSFP. Datasets were segmented using a 3D model-based ellipse-fitting approach with a single seed point placed manually above the celiac trunk. The segmented volumes were manually cropped from left subclavian artery to celiac trunk to avoid error due to side branches. Diameters, volumes and centerline length were computed for intraindividual comparison. For statistical analysis the Wilcoxon-Signed-Ranked-Test was used.
Average centerline length obtained based on N-MRA was 239.0±23.4 mm compared to 238.6±23.5 mm for CE-MRA without significant difference (P=0.877). Average maximum diameter obtained based on N-MRA was 25.7±3.3 mm compared to 24.1±3.2 mm for CE-MRA (P<0.001). In agreement with the difference in diameters, volumes obtained based on N-MRA (100.1±35.4 cm(3)) were consistently and significantly larger compared to CE-MRA (89.2±30.0 cm(3)) (P<0.001).
3D morphometry shows highly similar centerline lengths for N-MRA and CE-MRA, but systematically higher diameters and volumes for N-MRA.
Cardiovascular diagnosis and therapy. 04/2014; 4(2):80-7.
[Show abstract][Hide abstract] ABSTRACT: Endovascular repair has revolutionized the treatment of infrarenal aortic aneurysms. However, its application is still limited in patients with challenging access conditions such as small-caliber vessels, iliac tortuosity, excessive calcification or occlusive disease. The underlying manuscript addresses the crucial role of preoperative access vessel evaluation and summarizes recent developments in endograft manufacturing and surgical techniques allowing for coping with hostile access conditions. Furthermore, alternative access routes and complication management are discussed.
The Journal of cardiovascular surgery 04/2014; 55(2 Suppl 1):75-83. · 1.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Glo1 (glyxoalase I) is a cytosolic protein expressed in all mammalian cells. Its physiological function is the detoxification of MG (methylglyoxal), which is a potent precursor of AGEs (advanced glycation end-products). Although the impact of AGEs on different forms of vascular diseases has been intensively investigated, the evidence for the involvement of Glo1 and MG is still scarce. Recently, several studies have provided significant evidence for Glo1 having a protective effect on microvascular complications in diabetic patients, such as retinopathy and nephropathy. Regarding macrovascular complications, especially atherosclerotic lesions, the impact of Glo1 is even less clear. In the present article, we review the latest findings regarding the role of Glo1 and MG in vascular biology and the pathophysiology of micro- and macro-vascular disease.
Biochemical Society Transactions 04/2014; 42(2):528-33. · 2.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chronic vascular inflammation is a key hallmark in the pathogenesis of abdominal aortic aneurysm (AAA). Recent investigations have suggested that the inflammasome, a cytosolic multi-protein complex, recognizing pathogen associated molecular patterns, plays a role in atherosclerosis. However, its role in AAA inflammation has not yet been investigated. This pilot study analyzed inflammasome activation and its intramural localization in 24 biopsies from 11 patients with asymptomatic AAA versus 12 apparently healthy control aortic samples. Using a histological inflammation scale, grade 2/3 inflammatory changes with lymphoid aggregates/tertiary lymphoid organs were identified in 21 out of 24 AAA samples, whereas only 7 of the 12 control samples exhibited local grade 1 inflammatory changes. Strong expression of ASC, Caspase-1, Caspase-5, and AIM2 was detected by immunohistochemistry in both, sporadic infiltrating lymphoid cells as well as in lymphoid aggregates located in the outer media and adventitia of AAA samples. In contrast, inflammasome-positive cells were restricted to cholesterol plaque-associated areas and to single infiltrating cells in control aortas. Analysis of gene-expression using real-time PCR revealed significantly increased median mRNA levels of the inflammasome core components ASC, Caspase-1 and IL-1β in AAA tissue compared to normal aorta. Moreover, significantly increased median amounts of AIM2 protein and mature Caspase-5 (p20) were found in samples associated with high rupture risk compared with paired low rupture risk samples of the same AAA patient. We conclude from our data that AAA-associated lymphoid cells are capable of inflammasome signalling, suggesting that inflammasome activation is involved in the chronic inflammatory process driving AAA-progression.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to analyze midterm results of bypass patency and overall and aortic-related mortality rates of hybrid aortic procedures for thoracoabdominal aortic pathologies.
A retrospective study was performed considering prospectively collected data in two centers. From January 2001 to December 2012, 45 patients (33 men; mean age, 67.8 ± 7.6 years) received hybrid aortic procedures for thoracoabdominal aortic diseases (31 atherosclerotic aneurysms, 7 chronic expanding type B aortic dissections, 2 penetrating aortic ulcers, and 5 pseudoaneurysms), corresponding to 155 revascularized visceral abdominal arteries. Elective/emergency and staged/simultaneous approaches were 31 of 14 and 28 of 17, respectively. Patient demographics, clinical risk factors, and aortic morphological and procedural data were collected. End points were technical success, 30-day morbidity, reintervention and mortality, bypass graft patency, freedom from reintervention, and overall and aortic-related mortality during midterm follow-up. Mean follow-up was 2.2 ± 2.4 years.
Technical success was achieved in 86.6% (39/45) of patients. Thirty-day morbidity rate was 60% (paraplegia/paraparesis: 13.3%, stroke: 6.7%, renal failure: 31.3%, permanent dialysis: 4.4%). Thirty-day freedom from reintervention rates were 67.1% and 78.5%, respectively. Thirty-day occlusion of revascularized visceral vessels occurred in 11 (7.1%, 11/155) target arteries. In-hospital mortality rate was 24.4%. Primary graft patency after 1, 2, and 4 years was 89.7%, 85.3%, and 79%, respectively. Bypass thrombosis or stenosis developed in nine (6.8%, 9/132) vessels during follow-up. Of these, three patients required reintervention and one died. Freedom from reintervention rates after 1, 2, and 4 years were 45.6%, 45.6%, and 34.2%, respectively. Overall and aortic-related mortality rates after 1, 2, and 4 years were 32.6%, 41.4%, and 45.3% and 9.1%, 13.9%, and 13.9%, respectively.
A hybrid procedure for thoracoabdominal aortic pathologies in high-risk patient is feasible but carries a significant rate of early and midterm reintervention and death. Long-term surveillance of the visceral bypass is necessary because one-third of the patients will have bypass-related complications.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 01/2014; · 2.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To translate the individual abdominal aortic aneurysm (AAA) patient's biomechanical rupture risk profile to risk-equivalent diameters, and to retrospectively test their predictability in ruptured and non-ruptured aneurysms.
Biomechanical parameters of ruptured and non-ruptured AAAs were retrospectively evaluated in a multicenter study. General patient data and high resolution computer tomography angiography (CTA) images from 203 non-ruptured and 40 ruptured aneurysmal infrarenal aortas. Three-dimensional AAA geometries were semi-automatically derived from CTA images. Finite element (FE) models were used to predict peak wall stress (PWS) and peak wall rupture index (PWRI) according to the individual anatomy, gender, blood pressure, intra-luminal thrombus (ILT) morphology, and relative aneurysm expansion. Average PWS diameter and PWRI diameter responses were evaluated, which allowed for the PWS equivalent and PWRI equivalent diameters for any individual aneurysm to be defined.
PWS increased linearly and PWRI exponentially with respect to maximum AAA diameter. A size-adjusted analysis showed that PWS equivalent and PWRI equivalent diameters were increased by 7.5 mm (p = .013) and 14.0 mm (p < .001) in ruptured cases when compared to non-ruptured controls, respectively. In non-ruptured cases the PWRI equivalent diameters were increased by 13.2 mm (p < .001) in females when compared with males.
Biomechanical parameters like PWS and PWRI allow for a highly individualized analysis by integrating factors that influence the risk of AAA rupture like geometry (degree of asymmetry, ILT morphology, etc.) and patient characteristics (gender, family history, blood pressure, etc.). PWRI and the reported annual risk of rupture increase similarly with the diameter. PWRI equivalent diameter expresses the PWRI through the diameter of the average AAA that has the same PWRI, i.e. is at the same biomechanical risk of rupture. Consequently, PWRI equivalent diameter facilitates a straightforward interpretation of biomechanical analysis and connects to diameter-based guidelines for AAA repair indication. PWRI equivalent diameter reflects an additional diagnostic parameter that may provide more accurate clinical data for AAA repair indication.
European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 01/2014; · 2.92 Impact Factor