[Acetylsalicylic acid and dipyridamole: aggregation inhibition in the rabbit experiment].
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Administration, Oral↗
Biomedical subjects
P Polterauer
Publications and source records attributed to P Polterauer.
Prosthetic valve endocarditis due to Candida tropicalis complicated by multiple pseudoaneurysms.
Candida endocarditis is an unusual but severe complication caused by Candida albicans or other fungal species. We describe a case of prosthetic valve endocarditis due to Candida tropicalis, complicated by multiple pseudoaneurysms.
Aneurysm, False↗
Compliance and formation of distal anastomotic intimal hyperplasia in Dacron mesh tube constricted veins used as arterial bypass grafts.
Dilated and varicose veins constricted with a Dacron mesh tube were successfully used as arterial bypass grafts to avoid nonautogenous vascular prostheses. Mesh constriction has also been used to adapt the venous graft lumen to the diameters of grafted arteries. The influence of the external mesh on the wall elasticity of such venous grafts and the reactions of the host artery were not investigated. Elastic properties of mesh constricted autologous veins used as arterial grafts in femoropopliteal reconstructions, as well as consecutive formation of distal anastomotic intimal hyperplasia (DAIH), were investigated in this experiment. Twenty-four autologous venous grafts were implanted in 12 sheep. Grafts were left natural (Groups 1 and 3) or were constricted with an external Dacron mesh (Groups 2 and 4); their diameters were left unchanged (Groups 1 and 2) or were matched to the diameter of the host artery (Groups 3 and 4). Wall elasticity of the graft, distal anastomosis, and distal artery were measured by locally applied crystal transducers during surgery and follow-up. Formation and localization of DAIH was evaluated histomorphologically after a median of 8.3 months. Graft wall elasticity was found to be lower (54.6 vs. 147.9, P = 0.006) and overall DAIH was found to be higher in mesh tube grafts (49.42 vs. 20.8 microns, P = 0.001, Mann-Whitney U-test). No differences in elasticity and DAIH formation were observed between grafts with adapted and large diameters. Constriction of venous grafts by a Dacron mesh tube reduces graft wall elasticity and promotes formation of DAIH. To avoid such an increased mismatch in compliance while making use of the advantages of this method, the external mesh tube must not be brought close to the distal anastomotic area itself.
Anastomosis, Surgical↗
Spiral CT angiography in the assessment of abdominal aortic aneurysms after stent grafting: value of maximum intensity projections.
PURPOSE: Our goal was to evaluate the value of maximum intensity projections (MIPs) rendered from spiral CT in the assessment of abdominal aortic aneurysms after stent graft implantation. METHOD: Spiral CT of the aorta was performed in 28 patients 1 week after implantation of covered aortic stent grafts. MIPs were evaluated in a blinded fashion. Transaxial scans and intravenous angiographs were considered the reference standard. RESULTS: Stent deformity was evident on the MIPs in 5 cases and stent angulation was seen in 24 cases. The excluded aneurysmal sac was visualized in 14 (50%) cases. MIPs depicted the patent inferior mesenteric artery in 20 of 23 cases (87%). Renal artery occlusion (n = 3), leaks (n = 8), and parietal thrombi, (n = 3) were detected on the MIPs in all cases. CONCLUSION: MIPs are a valuable tool in the assessment of aortic stent grafts.
Aged↗
Development of 'no-reflow' phenomenon in ischemia/reperfusion injury: failure of active vasomotility and not simply passive vasoconstriction.
BACKGROUND/AIM: Local blood flow failure (no-reflow phenomenon) during ischemia/reperfusion (I/R) injury may be mediated by interstitial edema formation (passive vasoconstriction) and/or microvascular spasm (active vasoconstriction). The development of the no-reflow phenomenon in the rabbit hind limb I/R model and the influence of treatment with L-arginine and/or antioxidative vitamins were investigated. METHODS: Untreated rabbits were compared with those treated with L-arginine (4 mg/kg/min) or antioxidative vitamins (0.4 ml/kg) alone or in combination during hind limb I/R (2.5/2 h). Interstitial edema formation and microvessel diameter alterations were measured morphometrically. Capillary blood perfusion was measured continuously with laser Doppler flowmetry. RESULTS: I/R injury was expressed by interstitial edema formation (interstitial space increase by 80%), microvascular constriction (microvessel cross-sectional area decrease by 30%), and development of no-reflow phenomenon (blood flow reduction by 60%). Treatment with antioxidative vitamins alone or L-arginine alone reduced interstitial edema by 22 and 31%, consequently, while combined L-arginine/antioxidative vitamin treatment showed a more pronounced edema reduction by 40%. Treatment with only antioxidative vitamins failed to influence the development of no-reflow, although interstitial edema formation was reduced. L-Arginine treatment alone or in combination with antioxidative vitamins prevented microvascular constriction and preserved blood flow after reperfusion without development of no-reflow despite still apparent interstitial edema. CONCLUSIONS: Affections of active vasomotility and not merely passive changes of external pressure (i.e., interstitial edema formation) should be considered important in the development of microvascular constriction during 'no-reflow' phenomenon.
Animals↗
Positive effect of treatment with synthetic steroid hormone tibolon on intimal hyperplasia and restenosis after experimental endothelial injury of rabbit carotid artery.
BACKGROUND: Arterial intimal hyperplasia and following restenosis may be inhibited by estrogens. We investigated the effect of a synthetic steroid hormone, Tibolon: (a) on intima hyperplasia and restenosis in vivo, and (b) on production of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), endothelial cell proliferation and apoptosis in vitro. METHODS: Influence of Tibolon treatment (0.1 mg/kg body weight, during 3 days before and 3 weeks after the operation as a drinking solution once daily) on neointimal formation (measured by morphometry) and arterial wall damage (by qualitative histology) were investigated in vivo using an animal model of balloon injury of carotid artery. In human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (HMEC-1), the effect of Tibolon (0.1 microg/ml) on eNOS and VEGF was assessed by ELISA. Cell proliferation was induced by VEGF(165) and measured by BrdU incorporation assay, cell apoptosis was detected colorimetrically measuring DNA fragmentation. RESULTS: Balloon injury resulted in neointima formation and prominent damage of the carotid artery wall. Treatment with Tibolon increased luminal area, decreased intimal area and intima to media ratio, and promoted better reparation of damaged vessel wall. In vitro, Tibolon treatment did not influence the expression of eNOS protein in HUVEC as well as cell proliferation rate but reduced apoptosis of endothelial cells by about 40%. Additionally, this treatment suppressed basal and IL-1beta-stimulated synthesis of VEGF in HMEC-1. CONCLUSIONS: Tibolon treatment suppressed neointimal formation and promoted better reparation of damaged vessel wall in carotid artery after balloon injury. This positive effect seems to be associated with improved endothelial cell survival resulting possibly in increased NO production. It might be also related to the decrease of VEGF generation.
Animals↗
Obliterations of the proximal subclavian artery: to bypass or to anastomose?
A clinical series has been analysed to determine which of two similar, extrathoracic "extraanatomic" methods of treating proximal blocks of the subclavian artery is the superior option. From 1975 until 1988 direct carotid-subclavian anastomosis was used in 32 patients and carotid-subclavian bypass in 19. There were no statistically significant differences for the probability of postoperative survival (p less than 0.877 Breslow; p less than 0.774 Mantel), intraoperative blood loss or the duration of anaesthesia. Those patients who had undergone subclavian artery repair had a significantly longer survival than those following carotid bifurcation endarterectomy (p less than 0.002 Breslow, p less than 0.0002 Mantel). As patients with subclavian lesions have a reasonable life-expectancy, they may possibly experience late complications of their vascular repair. Therefore it seems important to select the most durable operation, and direct carotid subclavian anastomosis has a significantly greater patency rate than bypass (p less than 0.006 Breslow, p less than 0.006 Mantel). Patients with preoperative symptoms of cerebrovascular insufficiency had a lower probability of survival than those with upper extremity claudication, although this did not reach statistical significance (p less than 0.205 Breslow; p less than 0.198 Mantel).
Adult↗
Aorto-Y-bifurcation graft: Dacron versus PTFE. Preliminary results of a randomized prospective study.
A randomized prospective study comparing PTFE-Y and Dacron-Y-grafts with regard to function rate, morphology, hemodynamic differences along the proximal anastomosis and body of the graft, complications and quality of material was performed. Between March 1983 and February 1987, 112 patients were admitted to the study. Randomization including the criteria of age, sex, indication to operation (chronic occlusive disease, aneurysm) run-off, diabetes, nicotine consumption and operative approach (transperitoneal, retroextraperitoneal) followed the methods of adaptive randomization developed by Pocock and Simon and was well balanced. Function rate and complications as well as morphological alterations showed no significant differences in either group. During a mean observation period of 24 months, Group I yielded a 97% and Group II a 95% function rate (Kaplan-Meier). In all patients but one in each group with limb graft occlusions (n = 5) function was regained by successful thrombectomy and profundaplasty. With respect to Doppler ultrasound differences in flow pattern, in four patients with enlarged proximal side-end anastomosis and adequate--not to large--incision is recommended performing the proximal anastomosis.
Anastomosis, Surgical↗