| 11. |
- Dias, Nuno, et al.
(författare)
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Reply.
- 2008
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 1097-6809 .- 0741-5214. ; 47:4, s. 899-900
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 12. |
- Gasser, T. Christian, et al.
(författare)
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Failure properties of intraluminal thrombus in abdominal aortic aneurysm under static and pulsating mechanical loads
- 2008
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 0741-5214 .- 1097-6809. ; 48:1, s. 179-188
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: It has been suggested that mechanical failure of intraluminal thrombus (ILT) could play a key role in the rupture of abdominal aortic aneurysms (AAAs), and in the present study, this hypothesis has been investigated. An in vitro experimental approach has been proposed, which provides layer-specific failure data of ILT tissue under static and pulsatile mechanical loads. Methods. In total, 112 bone-shaped test specimens are prepared from luminal, medial, and abluminal layers of eight ILTs harvested during open elective AAA repair. Three different types of mechanical experiments, denoted as control test, ultimate strength test, and fatigue test were performed in Dulbecco's modified eagle's medium (DMEM) supplemented with fetal calf serum, L-ascorbic acid, and antibiotics at 37 degrees C and pH 7.0. In detail, fatigue tests, which are experiments, where the ILT tissue is loaded. in pulsatile manner, were carried out at three different load levels with a natural frequency of 1.0 Hz. Results. ILT's ultimate strength (156.5 kPa, 92.0 kPa, and 47.7 kPa for luminal, medial, and abluminal layers, respectively) and referential stiffness (62.88 kPa, 47.52 kPa, and 41.52 kPa, for luminal, medial, and abluminal layers, respectively) continuously decrease from the inside to the outside. ILT tissue failed within less than 1 hour under pulsatile loading at a load level of 60% ultimate strength, while a load level of about 40% ultimate strength did not cause failure within 13.9 hours. Conclusions. ILT tissue is vulnerable against fatigue failure and shows significant decreasing strength with respect to the number of load cycles. Hence, after a reasonable time of pulsating loading ILT's strength is far below its ultimate strength, and when compared with stress predictions from finite element (FE) studies, this indicates the likelihood of fatigue failure in vivo. Failure within the ILT could propagate towards the weakened vessel wall behind it and could initialize AAA failure thereafter.
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| 13. |
- Karlsson, Lars, 1959-, et al.
(författare)
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The effect of azithromycin and Chlamydophila pneumoniae infection on expansion of small abdominal aortic aneurysms : a prospective randomised double-blind trial
- 2009
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 0741-5214 .- 1097-6809. ; 50:1, s. 23-29
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of the study was to evaluate the effect of azithromycin on the expansion rate of small abdominal aortic aneurysms (AAAs), and to determine whether or not a correlation exists between serological markers for Chlamydophilia pneumonia (Cpn) infection and AAA expansion. METHODS: Nine vascular centers were included and 259 patients were invited to participate. Ten patients declined and 2 patients had chronic kidney failure, leaving a total of 247 patients. Inclusion criteria were: AAA 35-49 mm and age <80 years. Patients were randomized to receive either azithromycin (Azithromax, Pfizer Inc, New York, NY) 600 mg once daily for 3 days and then 600 mg once weekly for 15 weeks, or placebo in identical tablets. The ultrasound scans were performed in a standardized way within a month before inclusion and every 6 months for a minimum follow-up time of 18 months. Cpn serology was analyzed in blood samples taken at inclusion and 6 months later. Serum was analyzed for Cpn IgA and IgG antibodies by microimmunofluorescence (MIF). Computed tomography (CT) scans were done in 66 patients at inclusion and at 1 year for volume calculations. RESULTS: Thirty-four patients were excluded, ie, could not be followed for 18 months, 20 in the placebo group and 16 in the active treatment group. A total of 211 patients had at least two measurements and all were analyzed in an intention-to-treat analysis. Detectable IgA against Cpn was found in 115 patients and detectable IgG against Cpn in 160 patients. No statistically significant differences were found between the groups regarding median expansion rate measured by ultrasound scan (0.22 cm/year, interquartile range [IQR]: 0.09 to 0.34 in the placebo group vs 0.22, IQR: 0.12 to 0.36 in the treatment group, P = .85). Volume calculation did not change that outcome (10.4 cm(3)/year in the placebo group vs 15.9 cm(3)/year in the treatment group, P = .61). No correlation was found between serological markers for Cpn infection and the expansion rate. Patients taking statins in combination with acetylsalicylic acid (ASA) had significantly reduced expansion rate compared to patients who did not take statins or ASA, 0.14 cm/year vs 0.27 cm/year, P < .001. CONCLUSION: Azithromycin did not have any effect on AAA expansion. No correlation was found between serological markers for Cpn and AAA expansion, indicating no clinical relevance for Cpn testing in AAA surveillance. However, a significant reduction in AAA expansion rate was found in patients treated with a combination of ASA and statins.
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| 14. |
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| 15. |
- Koning, Olivier H. J., et al.
(författare)
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Fluoroscopic Roentgen stereophotogrammetric analysis (FRSA) to study three-dimensional stent graft dynamics
- 2009
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 1097-6809 .- 0741-5214. ; 50:2, s. 407-412
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Tidskriftsartikel (refereegranskat)abstract
- We report the clinical feasibility of fluoroscopic Roentgen stereophotogrammetric analysis (FRSA), a validated method to quantify, real time three-dimensional (3D) dynamic motion of stent grafts and the first clinical results after abdominal and thoracic endovascular repair (EVAR). Stent graft motion was measured at 30 (stereo) frames per second, during the cardiac cycle and in the patient after abdominal EVAR, due to respiratory action. Translational motions of the center of mass, diameter change, and rotational and axial motion could be measured. Quantification of 3D motion was not available until now. FRSA can provide crucial information on the forces exerted oil stent grafts and will, therefore, provide essential information for improvements in stent graft design. (J Vasc Surg 2009;50:407-12.)
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| 16. |
- Kragsterman, Björn, et al.
(författare)
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Outcomes of carotid endarterectomy in Sweden are improving : resluts from a population based registry
- 2006
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 0741-5214 .- 1097-6809. ; 44:1, s. 79-85
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In large randomized trials, carotid endarterectomy (CEA) for asymptomatic stenosis has shown a net benefit compared with best medical treatment. To justify an increased number of procedures for this indication, the perioperative risk of stroke or death must not exceed that of the trials. The aim of this study was to evaluate the outcome in routine clinical practice in Sweden in a population-based study. METHODS: The Swedish Vascular Registry (Swedvasc) covers all centers performing CEA. Data on all registered CEAs during 1994 to 2003 were analyzed both for the whole time period and for two 5-year periods to study alterations over time. Four validation procedures of the registry were performed. Medical records were reviewed for both a random sample and a target sample (a total of 12% of the CEAs for asymptomatic stenosis). Swedvasc data were cross-matched with the In-Patient-Registry (used for reimbursement) and the Population-registry (death). RESULTS: A total of 6182 CEAs were registered, 671 being for asymptomatic stenosis. In the validation process, no missed registration of major stroke or death was found. Patients with asymptomatic stenosis had, when the whole time-period was analyzed, a perioperative combined stroke or death rate of 2.1%. Outcome improved over time; the combined stroke or death rate decreased from 3.3% (11/330) from 1994 to 1998 to 0.9% (3/341) from 1999 to 2003 (P = .026). During the second time period, no patient with a perioperative major stroke or death was reported. CONCLUSIONS: This extensively validated national audit of CEA for patients with asymptomatic carotid artery stenosis showed results well comparable with those of the randomized trials. The results improved over time.
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| 17. |
- Kristmundsson, Thorarinn, et al.
(författare)
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Fenestrated endovascular repair for juxtarenal aortic pathology.
- 2009
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Ingår i: Journal of vascular surgery : official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter. - : Elsevier BV. - 1097-6809. ; 49, s. 568-574
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the outcomes after fenestrated endovascular aortic repair (f-EVAR) in a tertiary European referral center. METHODS: All patients treated with commercially available custom-made f-EVAR between September 2002 and June 2007 were prospectively enrolled in a computerized database including co-morbidities and aneurysm morphology. Patients were retrospectively analyzed. Follow-up consisted of clinical examinations and computed tomography (CT) scanning. RESULTS: A total of 54 patients were included in this study. Median age was 72 (interquartile range [IQR] 68-76) years and 85% were men. Median preoperative aneurysm diameter was 60 (53-66) mm. One hundred thirty-four vessels were targeted (43 scallops, 91 fenestrations) and 96 stents were placed (69 bare, 27 covered). Target vessel catheterization was achieved in 98% of cases. Two patients (3.7%) died within 30 days, 1 from trash embolization and multiorgan failure and 1 from retroperitoneal bleeding caused by a renal artery perforation. Three type I endoleaks occurred intraoperatively, two sealed pre-discharge and one was treated with a Palmaz stent (Cordis, Miami Lakes, Fla) on postoperative day 4. Thirteen patients had type II endoleaks, and 2 required treatment. The median clinical follow-up was 25 (12-32) months with median CT follow-up of 22 (4-26) months. Aneurysm diameter decreased >/=5 mm in 47%, was unchanged in 50%, and increased >/=5 mm in 3% of patients at 1 year. There were three type II endoleaks at 1-year follow-up, one of which was successfully treated after 19 months due to aneurysm growth. Ninety-six percent of target vessels remained patent during the study period and all occlusions occurred within the first year of follow-up. Five target vessels occluded (2 renal arteries [RAs] and 3 superior mesenteric arteries [SMAs]) without symptoms during follow-up and successful reinterventions were done on 2 stenosed RAs. Three patients suffered creatinine increase but none needed dialysis. One late aneurysm-related death occurred due to massive bleeding during redo surgery for infection. CONCLUSION: Despite complex anatomy or severe comorbidities in these patients f-EVAR has acceptable short- and midterm results in this series which includes a learning curve and offers a valid treatment alternative to patients unsuitable for standard EVAR or open repair.
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| 18. |
- Kuoppala, Monica, et al.
(författare)
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Long-term prognostic factors after thrombolysis for lower limb ischemia.
- 2008
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 1097-6809 .- 0741-5214. ; 47:6, s. 1243-1250
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This study assessed prognostic factors regarding long-term outcome for amputation and death among patients who underwent intra-arterial thrombolysis due to lower limb ischemia. METHODS: Consecutive patients with intra-arterial thrombolysis due to lower limb ischemia treated at the Department of Vascular Diseases, University Hospital of Malmö, between January 1, 2001, and December 31, 2005, were retrospectively reviewed. A multivariate Cox regression analysis was performed to determine independent predictors for amputation and death. RESULTS: A total of 220 intra-arterial thrombolysis procedures were performed in 195 patients (46% women). Median age was 73 years. Complete and partial thrombolysis was obtained in 41% and 38%, respectively. Hemorrhagic complications were documented in 33%, but only 6% (13 of 220) were interrupted. The amputation rate was 26% and mortality was 35% during a median follow-up of 32 months. Degree of lysis (hazard ratio [HR], 4.8; 95% confidence interval [CI], 2.4-9.7; P < .001), motor deficit at admission (HR, 4.0; 95% CI, 1.8-8.7; P = .001), foot ulcers (HR, 7.2; 95% CI, 2.2-23.4; P = .001), and ischemic heart disease (HR, 2.3; 95% CI, 1.1-4.8; P = .024) remained as independent factors associated with amputation. Renal insufficiency (HR, 2.4; 95% CI, 1.4-4.2; P = .003), ischemic heart disease (HR, 2.1; 95% CI, 1.2-3.7; P = .007), cerebrovascular disease (HR, 2.2; 95% CI, 1.2-4.0; P = .009), foot ulcers (HR, 3.2; 95% CI, 1.2-8.6; P = .019), and acute lower limb ischemia (HR, 3.4; 95% CI, 1.1-10.1; P = .028) remained as independent factors associated with mortality. CONCLUSIONS: Thrombolysis is successful, with few major complications in most patients with lower limb ischemia. Patients with ischemic heart disease and foot ulcers are at higher long-term risk for both amputation and death. A lesser degree of lysis and motor deficit were associated with higher amputation rates. The presence of such negative prognostic factors may help clinicians to deny further invasive vascular treatment. Renal insufficiency, cerebrovascular disease, and acute lower limb ischemia were associated with increased mortality.
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| 19. |
- Kölbel, Tilo, et al.
(författare)
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Activated protein C-protein C inhibitor complex: a new biological marker for aortic aneurysms.
- 2006
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 1097-6809 .- 0741-5214. ; 43:5, s. 935-939
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The concentration of the complex between activated protein C (APC) and protein C inhibitor (PCI) is a measure of thrombin generation. We studied whether it can provide information useful for the diagnosis and treatment of arterial vascular disease. Methods: Blood was obtained from 429 vascular patients admitted consecutively during September 2004 to March 2005. The APC-PCI complex was measured by using a sandwich immunofluorometric method. The patients were divided into cohorts according to the planned treatment and compared with a control group of healthy individuals. Results: The APC-PCI complex concentration varied from 0.08 to 2.50 mu g/L. In the cohort of patients with aortic aneurysms (n = 78), the median APC-PCI value was 0.45 (10(th) to 90(th) percentile, 0.24-1.47), and values were clearly increased compared with all other cohorts (P <.0001). Patients with carotid disease (n = 73) yielded a median of 0.22 (10(th) to 90(th) percentile, 0.15-0.48). The median for claudicants (n = 74) was 0.26 mu g/L (10(th) to 90(th) percentile, 0.15-0.75), which was higher than in those (n = 97) with critical ischemia (0.20; 10(th) to 90(th) percentile, 0.13-0.36; P <.0023). The cohort with other forms of antherosclerotic disease (n = 40) had a median of 0.23 (10(th) to 90(th) percentile, 0.14-0.42), whereas the value for a cohort of 21 patients with venous disease was 0.19 (10(th) to 90(th) percentile, 0.10-0.34). The median was 0.15 (10(th) to 90(th) percentile, 0.10-0.23) for the control group (n = 121). Conclusions: Patients with atherosclerosis had an increased APC-PCI concentration that corresponded to increased generation of thrombin. Patients with aortic aneurysm had a threefold higher median concentration than the control group. We suggest that this remarkable increase is caused by the local activation of coagulation, and we surmise that APC-PCI measurements can be used as a screening tool to identify patients with aortic aneurysms.
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| 20. |
- Kölbel, Tilo, et al.
(författare)
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Carotid artery entrapment by the hyoid bone.
- 2008
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Ingår i: Journal of vascular surgery : official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter. - : Elsevier BV. - 1097-6809. ; 48:4, s. 1022-1024
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Tidskriftsartikel (refereegranskat)abstract
- We report a patient with a transient ischemic attack presumably caused by an entrapment of the internal carotid artery by the hyoid bone and without a significant carotid artery stenosis. The patient was operated on, with a release of the right internal and external carotid artery and resection of the right greater cornu of the hyoid bone. One year after treatment, the patient has not experienced any further neurologic symptoms, and a color duplex scan showed no stenosis of the right carotid artery. The hyoid bone is a potential cause of damage to the carotid vessels, depending on the individual's anatomy. Provocative maneuvers can be performed in patients with cerebrovascular symptoms who are not demonstrated to have significant anatomic stenosis with carotid imaging.
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