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Aim: The aim of this study was to collect clinical information on the performance of the Endurant® (II) Stent Graft System for endovascular repair in anatomically challenging infrarenal aneurysms, and to critically assess whether the current instructions for anatomic eligibility for endovascular treatment with this system are still applicable., Methods: Initiated by doctors, EAGLE is a prospective, non-interventional study, aiming to enrol 250 patients in 20 experienced centres across several countries worldwide. EAGLE focuses on patients with challenging angulation or neck length. To minimize the risk of selection bias and enhance data quality, EAGLE eligibility will be determined by an independent core-lab and efforts will be made to secure consecutive enrolment of challenging cases. The EAGLE database is designed to merge with the on-going ENGAGE database, which enables comparative analysis of cases and results., Results: The primary endpoint is treatment success at 30 days, 12 months and yearly up to 5 years postimplant., Conclusion: Separate studies on the performance of EVAR in challenging anatomy are necessary to demonstrate safety and effectiveness of the latest generation stent-grafts, which is essential in making a balanced judgment about the optimal management of AAAs.

The objective was to determine the activation of white blood cells (WBCs) and endothelial cells in patients with healed venous ulcer and the influence of the standing position and of treatment with flavonoids. Ten patients with a healed venous ulcer were treated with flavonoid substance (90% diosmin), 1000 mg three times daily for 30 days. Blood samples were taken from arm and dorsal foot veins before and after standing for 30 minutes. Blood sampling was performed before treatment, after three days, one month and three months. The activation of WBCs was determined by measuring adhesion molecule CD11b and CD18 expression on the surface of granulocytes and monocytes. In addition, interleukin 6 (IL-6), IL-8, soluble E-selectin (sE-selectin), sL-selectin and sICAM-1 levels in serum were quantified. The results showed that standing did not influence any of the measured parameters significantly. Expression of CD11b adhesion molecules on granulocytes was significantly up-regulated (p = 0.044) after treatment with flavonoids for one month, but this increase was not significant (p = 0.056) two months after the treatment period compared with the baseline level. The expression of CD18 remained unchanged. Baseline expression of CD11b or CD18 on monocytes did not change significantly during the study period. Neither was any significant change observed in the levels of IL-6, IL-8 or the soluble adhesion molecules. It was concluded that flavonoid treatment for 30 days increased the expression of CD11b adhesion molecules on circulating granulocytes. No general effect on the inflammatory process could be observed as assessed by levels of cytokines and soluble adhesion molecules. Possible explanations for these findings could be that a decreased number of primed granulocytes leave the circulation due to a changed WBC/endothelial cell interaction or that flavonoids have a direct effect on granulocytes. Further studies are needed to clarify the mode of action of flavonoids in chronic venous disease.

Inflammatory mediators such as cytokines produced by white blood cells (WBCs) at the site of implantation are important for the biocompatibility of vascular grafts. The aim of the present study was to demonstrate the tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) release from WBCs incubated with expanded polytetrafluoroethylene (ePTFE) or woven Dacron grafts. In a second series the effects of pentoxifylline (PTX) and iloprost (ILO), both known to inhibit white blood cell function, on this release were determined. Woven Dacron grafts induced significantly higher release of both TNF-alpha and IL-6 compared to ePTFE. TNF-alpha was detectable first after 2 h, whereas IL-6 was seen after 4 h. Maximum values were reached at 6 and 12 h, respectively. The addition of an endotoxin gave more pronounced patterns of cytokine release not influenced by time. Preincubation with both PTX and ILO at final concentrations of 100 and 10 micrograms/mL, respectively, reduced significantly the TNF-alpha release without differences between the two graft materials, whereas the effect on the IL-6 release varied and was graft material-dependent. In conclusion, graft material-dependent induction of TNF-alpha and IL-6 from WBCs was demonstrated. PTX and ILO influenced the cytokine release. It might be suggested that graft material-induced cytokine production could contribute to intimal hyperplasia in vivo. The present findings encourage further studies regarding graft material-induced WBC alterations and the role of pharmacologic agents influencing this function.

Purpose: To review the findings of two studies investigating the apparent differences in inflammatory responses demonstrated in patients undergoing endovascular as opposed to classic surgical treatment of abdominal aortic aneurysms (AAAs)., Methods: The clinical course of seven patients treated with an endoluminal procedure (AAA-E) and seven patients undergoing conventional surgery (AAA-C) were compared (all men; ages 52 to 80 years). Blood samples were taken pre-, intra-, and postoperatively for up to 7 days. Inflammatory responses were assessed from measurement of interleukins (IL)-1 beta, IL-6, IL-8, and tumor necrosis factor (TNF-alpha); complement proteins C1q, C4, C5a, and terminal complement complexes, C5b-C9; and C-reactive proteins. Granulocyte and monocyte surface adhesion molecule expression was determined indirectly using a panel of monoclonal antibodies against CD11a, CD11b, CD11c, CD18, and L-selectin in donor white blood cells exposed to patient plasma., Results: In six of the AAA-E patients, blood pressure decreases were recorded during the introduction of the device. Elevated body temperature was sustained for 2 to 5 days postoperatively in the AAA-E group. IL-6 levels were significantly higher in AAA-C patients (p < 0.0005), while TNF-alpha release was recorded in the AAA-E group only. CD11b, CD11c, and CD18 molecules on both granulocytes and monocytes were significantly upregulated 60 minutes after the endovascular procedure compared to conventional surgery., Conclusions: Endovascular aortic aneurysm repair apparently induces a significant inflammatory response, mainly involving TNF-alpha release, which differs from open AAA repair. These inflammatory responses, which may be related to the observed intraprocedural blood pressure decreases, could be caused by cell activation arising from intra-aneurysmal device manipulation.

The expression of surface adhesion molecules on granulocytes, monocytes (CD11a, CD11b, CD11c, CD18, L-selectin), and platelets (P-selectin, gpIIb-IIIa) was determined after incubation with different graft surfaces [expanded polytetrafluoroethylene (ePTFE) or woven Dacron]. Woven Dacron grafts upregulated the CD11b and CD11c surface antigens on both granulocytes and monocytes. Both graft materials demonstrated increased expression of CD11a and CD18 adhesion molecules on white blood cells at 30 min, followed by a downregulation. Maximum L-selectin expression was seen at 120 min on granulocytes and at 90 min on monocytes without differences between the graft materials. A rapid downregulation of gpIIb-IIIa complexes on platelets was noticed, while no expression of platelet P-selectin molecules was observed. In conclusion, both graft materials induced alteration of the white blood cell adhesion molecule expression, but the intensity and time course were dependent on the cell type and the graft material, suggesting that different mechanisms might be implicated. The expression of platelet surface antigens was less clearly influenced. The clinical significance of an enhanced cell surface antigen receptor expression caused by woven Dacron (CD11b, CD11c) has to be further studied. However, determination of adhesion molecule expression might offer possibilities to predict biocompatibility.

Endothelial Nitric Oxide Synthase (eNOS) mediates the conversion of L-argine to NO and citrulline, which requires Nicotinamide Adenine Dinucleotide Phosphate (NADPH) as an essential cofactor. Evidence has been given that NOS accounts for the NADPH-diaphorase activity. The aim of the present study was to identify the histochemical and immunocytochemical appearance of NADPH-diaphorase and von Willebrand factor (factor VIII) respectively, in endothelial cells (ECs) during healing of stretch-expanded polytetrafluoroethylene (ePTFE) arterial grafts. On six Swedish domestic pigs an iliac bypass was bilaterally performed using 6 mm stretch-ePTFE grafts. The animals were allowed to survive one, two or four weeks. After explanation the grafts were prepared for NADPH-diaphorase histochemistry and factor VIII immunohistochemistry. Positive staining for the two identification markers was demonstrated after two weeks, whereas a more intense staining was seen after four weeks at the proximal and distal anastomoses, indicating maturation by time. No stained cells were observed at the mid-region of the grafts at any time. The cells differed from normal ECs, the former being less intense which may reflect immature ECs and probably a decreased expression of NO. In conclusion, the present study suggests tha NADPH-d histochemistry can be used to identify ECs. Whether a lower expression of NO compared to normal cells also means a reduced function, capable of causing adverse events has to be further evaluated.

Objective: To analyse the quantity of heparin retention on heparin bonded collagen coated knitted Dacron grafts (HCD) and heparin bonded knitted Dacron grafts without interluminal collagen coating (HD) after they had been exposed to shear stress in an artificial circulation model., Experimental Design: A comparative study., Setting: University Hospital, Department of Surgery., Methods: HCD grafts were exposed to shear stress during 2, 24, 48, and 168 hours, and HD grafts during 1, 2, 3 and 4 weeks. Heparin retention on the graft walls was determined by a method based on the measurements of total sugars., Results: HCD grafts showed no loss of heparin from the graft-surface when exposed to a flow of 200 ml/min up to 168 hrs. HD grafts demonstrated an initial loss of heparin from 8 mg/g to 3 mg/g/graft-segment within one week after which the level was stable during the remaining three weeks., Conclusion: Based on the present experimental setting it seems reasonable to conclude that the heparin-collagen layer remains stable but heparin alone is partly washed out by shear stress. To measure the release of heparin under the influence of the bloodstream including mechanisms for the slow degradation of collagen, a more sensitive method for heparin analysis is required.

Objective: To evaluate the dilatation-rate of a reverse locknitted Dracon graft., Experimental Design: Comparative study, a follow-up after 5 years., Setting: Department of Surgery, University Hospital., Patients: During 1987 to 1990, 105 patients underwent elective aorto-bifemoral bypass surgery for aorto-iliac occlusive disease. Nineteen patients received a reverse locknitted Dacron graft. During follow-up in 1993 ten patients were available for evaluation of graft-diameter. For comparison 14 patients who received a wrap knitted Dacron graft (12 collagen impregnated and two uncoated) operated during the same time period were randomly chosen., Intervention: CT-scan evaluation., Results: A significantly lower increase (a mean aortic body dilatation of 6.8%) of the graft-size was found for this reverse locknitted Dacron (p < 0.001) compared to two wrap knitted Dacron grafts (collagen impregnated and uncoated knitted Dacron) (31.0% and 37.8% respectively). At the femoral level mean dilatation rates of respectively, 2.5%; 23.8% and 31.7% were found. Mural thrombus was observed in three grafts. No false aneurysms, graft degradation or graft occlusions were observed., Conclusion: It was concluded that reverse locknitted Dacron dilates to a minimum, however, further studies are needed to evaluate the relation of graft-composition/structure and dilatation.

Out of 229 patients operated due to abdominal aortic aneurysms, 51 (22.3%) had prolonged (> 120 hours) postoperative intensive care stay. The mortality rate in this group was 27% representing 46% of the total mortality. Twenty-five of these 51 patients had postoperative septic complications, meaning positive blood cultures. Clinically wound infections (11), acalculous cholecystitis (9), urinary tract infections (9), septicemia (6), and diffuse peritonitis or abdominal abscess were found (4). Reoperations, time for ventilatory support, incidence of renal failure and dialysis, gastrointestinal complications and mortality were all frequent in patients with septic postoperative complications as compared to those with non-septic complications, the latter mainly of cardiovascular origin. Signs of organ dysfunction should raise a suspicion of a septic complication and prompt insertion of diagnostic procedures and therapeutic interventions are necessary in order to minimize morbidity and mortality.

The incidence of renal artery stenosis (RAS) was prospectively evaluated by aortofemoral angiography in 100 patients with peripheral vascular disease (PVD) to find whether RAS was a more common finding in hypertensive than in normotensive patients. For a possible association with RAS, risk factors, clinical and angiographical variables were evaluated. Nephrotoxicity of the contrast medium Iohexol was elucidated. A follow-up of six month was performed in patients with severe stenosis or total occlusion of the renal arteries. Of the 49 patients with a renal artery lesion 26.5% were normotensive and 73.5% hypertensive. Hypertension was significantly correlated to RAS. Reconstructive vascular procedures were during the follow-up performed in 47.3% of the patients with severe RAS or occluded renal arteries, two patients underwent a renal artery revascularization, none of them got a postoperative blood pressure decrease. Hypertension in patients with peripheral vascular disease is predictive for renal artery stenosis and a possible renovascular hypertension should be evaluated. Surgery for renal artery stenosis in peripheral vascular diseased patients should, however, probably be performed firstly to reduce the risk for occlusion. The effect on the blood pressure can not be predicted without a more careful analysis that the blood pressure is renin-dependent. Iohexol showed low nephrotoxicity, also in patients with renal artery disease.

To estimate the frequency of renal artery stenosis, and to detect the correlation between renal artery stenosis and hypertension, 450 consecutive patients with peripheral vascular disease (PVD) were selected. All subjects had undergone aorto-femoral conventional angiography. For a possible association with renal artery stenosis, risk factors, clinical and angiographical variables were evaluated e.g.: age, sex, diabetes mellitus, smoking habits, use of antihypertensive drugs, serum creatinine, serum cholesterol, ECG pathology, side of the renal artery lesion, bilateral stenoses, post-stenotic dilatation, number of renal arteries, aortic atherosclerosis, size of the kidneys and angiography induced renal dysfunction. Renal artery stenosis (RAS) was found in 49.1%, 117 patients had a moderate and 104 had a severe stenosis. Of the 221 patients with a renal artery lesion, 44 were normotensive, 177 hypertensive. Hypertension was significantly correlated to RAS. An association was also found for age over 70 years, smoking and pathologic ECG. It is concluded that renal artery stenosis is very common in a population with peripheral vascular disease, and the results achieved from this study makes it worthwhile to identify possible functional markers in a prospective study.