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Biomedical subjects

Rolf Bambauer

Publications and source records attributed to Rolf Bambauer.

11 recordsLinked to original sources
PubMed2005

Is lipoprotein (a)-apheresis useful?

Numerous epidemiological investigations have shown the importance of cholesterol, and in particular low density lipoprotein (LDL), and of the lipoproteins in the development of coronary sclerosis. A continuing relationship between cholesterol levels and coronary morbidity has been established. The LDL concentration in the blood is, in particular, to be made responsible for the development of arteriosclerosis and especially of coronary heart disease (CHD). Lipoprotein (a) [Lp(a)], as a risk factor for premature cardiovascular and cerebrovascular diseases, can be lowered by LDL-apheresis. Especially in isolated high levels of Lp(a) with CHD or polygenic hypercholesterolemia with elevated Lp(a) levels, LDL-apheresis can be indicated and can be useful to improve endothelium regulation and induce changes in coronary tone by an increase in endothelial derived relaxing factor. Lipoprotein (a) can be dramatically lowered by LDL-apheresis, but clinical improvement especially by low LDL is not still not clarified. Studies with weekly apheresis with statins versus drug therapy alone are necessary. To clarify the controversial discussions of whether lowering Lp(a) may be unnecessary or necessary to arrest progression of CHD, more clinical and randomized studies are needed. Lipoprotein (a) can be also lowered by current LDL-apheresis methods.

Adsorption↗
PubMed2004

Large bore catheters with surface treatments versus untreated catheters for vascular access in hemodialysis.

Infection, thrombosis, and stenosis are among the most frequent complications associated with blood-contacting catheters. Complications resulting from infection remain a major problem for hemodialysis catheters, with significant numbers of catheters being removed due to catheter-related sepsis. Numerous strategies have been employed to reduce the occurrence of infection and im-prove long-term outcomes, with varying degrees of success. The most important is the careful and sterile handling by the attending staff of the catheters during hemodialysis treatments to minimize or stop a microbial colonization of the skin and the catheter. Another approach is coating the external surface of the catheters with substances which are antibacterial like silver and/or substances with low thrombogenicity like silicone. This investigation reviews results of animal and clinical experiments conducted to assess the efficacy and biocompatibility of silver and silicone coated dialysis catheters. It is concluded that silver coatings can reduce bacterial colonization and occurrence of infection associated with these devices. The catheters employing ion implantation of silicone rubber showed low thrombogenicity. Results of the studies indicate that ion beam based processes can be used to improve thrombus and infection resistance of blood contacting catheters. A new development is the microdomain structured surface (PUR-SMA coated catheters). Preliminary results with these catheters are very encouraging.

Animals↗
PubMed2004

Complications in large-bore catheters for extracorporeal detoxification methods.

Catheters for large vessels have become essential tools for the management of hospitalized or chronically ill patients requiring intensive medical treatments such as extracorporeal detoxification procedures. The increased use of such devices has been accompanied by a corresponding increase in complications, such as infection, sepsis, and thrombosis. In two retrospective studies, the first (1979-1990) with 1672 patients and 2626 large-bore catheters and the second (1996-2001) with 182 patients and 332 acute catheters, the frequency of infections, thrombosis, bleeding, and other side-effects were investigated. All complications and side-effects are presented. In total, the complication rate was in the first study 27.7% (internal jugular vein 23.8% in 2105 catheters, subclavian vein 43.5% in 521 catheters) and in the second study 32.2% (internal jugular vein 20% in 231 catheters, subclavian vein 60.6% in 94 catheters, femoral vein 57.1% in 7 catheters). The majority of complications were puncture not possible, puncture of the artery abscess, septicemia, bleeding, thrombosis, and faults in catheter material. To minimize these complication rates the handling of the inserted catheters before, during, and after the hemodialysis or apheresis treatment is minimized.

Blood Component Removal↗
PubMed2003

Side-effects and complications in large-bore catheters for apheresis.

Vascular catheters have become essential tools for management of hospitalized or chronically ill patients requiring intensive medical treatments such as extracorporeal detoxification procedures. The increased use of such devices has been accompanied by a corresponding increase in complications, such as bloodstream infection and thrombosis. In a retrospective study 332 large bore catheters which were inserted in 182 patients in the inferior or superior vena cava were investigated. The complication rate was in internal jugular vein puncture (N = 231) with 20% low and in the subclavian vein puncture (N = 94) with 60.5% and in the femoral vein puncture (N = 7) with 57.1% very high. The majority of complications were puncture not possible, puncture of the artery, abscess, septicemia, bleeding and thrombosis. To minimize the complication rate the surface of some catheters were treated and the microdomain structured surface inserted. The first results are very encouraging and should help to make large bore catheters safer.

Blood Component Removal↗
PubMed2003

Long-term catheters for apheresis and dialysis with surface treatment with infection resistance and low thrombogenicity.

Infection, thrombosis, and stenosis are among the most frequent complications associated with blood-contacting catheters. These problems are usually related to surface properties of the base catheter material. Surface treatment processes, such as ion implantation and ion beam assisted deposition (IBAD) and microdomain structured surfaces, can be used to mitigate such complications. This study evaluated silver coated and implanted large bore catheters used for extracorporeal detoxification. In a 186 patient prospective study, 225 large bore catheters were inserted into the internal jugular or subclavian veins. Eighty-five surface-treated catheters (Spi-Argent, Spire Corporation, Bedford, MA, USA) and 28 catheters with surface treatment (Spi-Silicone, Spire Corporation) were inserted in 90 patients. One hundred and twelve untreated catheters placed in 96 patients served as controls, After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using a scanning electron microscope (SEM). Bacterial colonization was observed in 8% of the treated catheter compared with 46.4% of untreated catheters. The SEM investigations showed all treated catheters to possess low thrombogenicity. Catheters with microdomain structured surfaces showed same results in preliminary observation. The surface treatments of the large bore catheters can be used to improve thrombus and infection resistance of blood contacting catheters.

Bacterial Infections↗
PubMed2003

Low-density lipoprotein apheresis: an overview.

Atherosclerosis with myocardial infarction, stroke, and peripheral cellular disease still maintains its position at the top of morbidity and mortality statistics in industrialized nations. Established risk factors widely accepted are smoking, arterial hypertension, diabetes mellitus, and central obesity. Furthermore, there is a strong correlation between hyperlipidemia and atherosclerosis. The prognosis of patients suffering from severe hyperlipidemia, sometimes combined with elevated lipoprotein (a) (Lpa) levels, and coronary heart disease (CHD) refractory to diet and lipid-lowering drugs is poor. For such patients, regular treatment with low-density lipoprotein (LDL) apheresis is the therapeutic option. Today, there are four different LDL apheresis systems available: immunoadsorption, heparin-induced extracorporeal LDL/fibrinogen precipitation, dextran sulfate LDL adsorption and LDL hemoperfusion. Regarding the different LDL apheresis systems used, there is no significant difference with respect to the clinical outcome or concerning total cholesterol, LDL, high-density lipoprotein (HDL), or triglyceride concentrations. With respect to elevated Lpa levels, however, the immunoadsorption method seems to be the most effective. In 45 patients (25 women, 20 men) suffering from familial hypercholesterolemia resistant to diet and lipid lowering drugs, low-density lipoprotein (LDL) apheresis was performed over 95.6 +/- 44.7 months. Four different systems (Liposorber, 32 of 45, Kaneka, Osaka, Japan; Therasorb, 6 of 45, Baxter, Munich, Germany; Lipopak, 2 of 45, Pocard, Moscow, Russia; and Dali, 5 of 45, Fresenius, St. Wendel, Germany) were used. With all methods, average reductions of 57% for total cholesterol, 55.9% for LDL, 75.8% for lipoprotein a (Lpa), and 45.9% for triglycerides, and an average increase of 14.3% for HDL were reached. Severe side-effects such as shock or allergic reactions were very rare (0.3%) in all methods. In the course of treatment, an improvement in general well-being and increased performance were experienced by 44 of 45 patients. The present data demonstrate that treatment with LDL apheresis of patients suffering from familial hypercholesterolemia resistant to maximum conservative therapy is very effective and safe even in long-term application.

Coronary Artery Disease↗
PubMed2003

Silver coating of dialysis catheters to reduce bacterial colonization and infection.

Complications resulting from infection remain a major problem for hemodialysis catheters, with significant numbers of catheters being removed due to catheter-related sepsis. Numerous strategies have been employed to reduce the occurrence of infection and improve long-term outcomes, with varying degrees of success. One promising approach is coating the external surface of catheters with silver using physical vapor deposition processes. This article reviews results of animal and clinical experiments conducted to assess efficacy and biocompatibility of silver-coated dialysis catheters. It is concluded that silver coatings can reduce bacterial colonization and occurrence of infection associated with these devices.

Animals↗
PubMed2003

Efficacy and safety of a new whole-blood low-density lipoprotein apheresis system (Liposorber D) in severe hypercholesterolemia.

Low-density lipoprotein (LDL) apheresis is an extracorporeal modality to lower LDL cholesterol. While most of the devices eliminate LDL particles from plasma, a recently introduced whole-blood perfusion column (DALI) adsorbs lipoproteins directly from whole blood. We investigated the efficacy and safety of a new whole-blood LDL apheresis system (Liposorber D) in 10 patients with severe hypercholesterolemia in a multicenter trial. In 93 LDL aphereses, the mean reduction in LDL cholesterol and lipoprotein(a) was 62.2 +/- 11.5% and 55.6 +/- 16.9%, respectively (P < 0.01). If hemodilution during apheresis was considered, the reductions were 58.0 +/- 10.9 and 55.3 +/- 10.9%, respectively (P < 0.01), while high-density lipoprotein (HDL) cholesterol did not change significantly. Three mild episodes of hypocalcemia and two mild episodes of arterial hypotension were observed; however, LDL apheresis could be continued in each case. In conclusion, the new whole-blood LDL apheresis with Liposorber D is a safe, simple, and useful modality to reduce LDL cholesterol and lipoprotein(a) in cardiovascular high-risk patients.

Adult↗
PubMed2002

Low-density lipoprotein apheresis: clinical results with different methods.

In 40 patients (22 women, 18 men) suffering from familial hypercholesterolemia resistant to diet and lipid lowering drugs, low-density lipoprotein (LDL) apheresis was performed over 84.9 +/- 43.2 months. Four different systems (Liposorber, 28 of 40, Kaneka, Osaka, Japan; Therasorb, 6 of 40, Baxter, Munich, Germany; Lipopak, 2 of 40, Pocard, Moscow, Russia; and Dali, 4 of 40, Fresenius, St. Wendel, Germany) were used. With all methods, average reductions of 50.6% for total cholesterol, 52.2% for LDL, 64.3% for lipoprotein (a) (Lp[a]), and 43.1% for triglycerides, and an average increase of 10.3% for high-density lipoprotein (HDL) were reached. Severe side effects such as shock or allergic reactions were very rare (0.5%) in all methods. In the course of treatment, an improvement in general well being and increased performance were experienced by 39 of 40 patients. Assessing the different apheresis systems used, at the end of the trial, there were no significant differences with respect to the clinical outcome experienced with the patients' total cholesterol, LDL, HDL, and triglyceride concentrations. However, to reduce high Lp(a) levels, the immunoadsorption method with special Lp(a) columns (Lipopak) seems to be most effective: -59% versus -25% (Kaneka) - (Baxter), and -29% (Dali). The present data demonstrate that treatment with LDL apheresis of patients suffering from familial hypercholesterolemia resistant to maximum conservative therapy is very effective and safe even in long-term application.

Blood Component Removal↗