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Biomedical subjects

W Kasper-König

Publications and source records attributed to W Kasper-König.

6 recordsLinked to original sources
PubMed2005

Effect of different operative techniques for myocardial revascularisation on hemodynamics and myocardial perfusion in a porcine model.

BACKGROUND: During surgical coronary revascularisation hemodynamics and myocardial contractility can be affected. This in vivo study aimed to determine the effects of different operative techniques on hemodynamics and regional myocardial perfusion. METHODS: In 24 pigs IMA to LAD bypass was constructed using ECC (n = 8) and cardioplegic arrest, OPCAB techniques (n = 8), or the Impella elect 100 support device (n = 8). 8 animals received a sham operation. Mean arterial pressure (MAP), cardiac output (CO), and left ventricular pressure (LVP, LVdp/dt) were recorded. Regional myocardial perfusion (RMP) of both ventricles was assessed by fluorescent microspheres. RESULTS: MAP significantly decreased during revascularisation in all groups ( p < 0.05), staying below preoperative values thereafter ( p < 0.05). After ECC norepinephrine was administered to maintain MAP. CO and LVdp/dt were impaired more distinctly during OPCAB than with Impella ( p < 0.05) during subsequent recovery. RMP showed global reactive hyperemia during early reperfusion after ECC, remained unchanged in OPCAB, and showed low flow during and after Impella pump run ( p < 0.05). CONCLUSIONS: ECC led to hemodynamic impairment with post-ischemic reactive hyperemia. OPCAB created hemodynamic depression but left RMP unchanged. Hemodynamic depression can be reduced by the Impella pump, however regional myocardial blood flow is decreased.

Animals↗
PubMed2003

Risk factors influencing the outcome after surgical treatment of complicated deep sternal wound complications.

BACKGROUND: Median sternotomy is the most frequently used incision for cardiac procedures but carries a substantial risk for deep sternal wound infections and/or sternal dehiscence. In contrast to previous studies that examined risk factors for sternal infections this study evaluates factors that lead to poor outcome after surgical revision of the non healing sternum. METHODS: Between 1985 and 1999, 193 adults (mean age 64 +/- 9 years, m/f = 3/1) necessitated sternal revisions (incidence 1.93%). Pre-, intra- and post-operative risk factors were evaluated for their influence on the outcome after sternal revision. RESULTS: 65 of the 193 patients had a complicated course: ten (5.2%) died due to sepsis/multi organ failure (n = 6) or cardiac causes (n = 4). 32 patients (16.6%) needed several revisions, 17 (9%) were discharged with sternal instability, 5 (3%) with chronic fistula and one with persistent osteomyelitis. Univariate and multivariate analysis identified cardiopulmonary resuscitation (odds ratio (OR) = 11.188, p = 0.010), corticoid treatment (OR = 7.043, p = 0.0055), diabetes (OR = 4.130, p = 0.0128), smoking history (OR = 2.996, p = 0.0041), renal insufficiency (hazard ratio (HR) = 1.884), old age (OR = 1.108, p = 0.0266), high body mass (HR = 1.06), ECC time (p = 0.023), cross clamp time (p = 0.028), systemic hypothermia (p = 0.016), non-use of IMA (p = 0.042) or prolonged ventilation as risk factors for mortality or poor outcome. No correlation between sternal closure technique, mediastinal irrigation or antibiotic therapy and outcome after mediastinal revision could be found. CONCLUSIONS: To avoid disappointing results after sternal revision one should aim to preoperatively identify high-risk patients and aggressively address risk factors. This rather than modifications of the surgical and medical approach might improve the outcome of patients with mediastinal complications.

Age Factors↗
PubMed1997

Transgenic human decay accelerating factor makes normal pigs function as a concordant species.

BACKGROUND: Increasing interest has focused on xenotransplantation as a potential solution to the organ shortage. To overcome hyperacute rejection, pigs have been produced that are transgenic for human decay accelerating factor (DAF). For the evaluation of the effects of human DAF, an ex vivo working heart model was used. METHODS: We compared hemodynamic performance of four transgenic pig hearts (group A) with that of four Landrace pig hearts (group B) and eight rhesus monkey hearts (group C). For perfusion fresh blood had been taken from healthy volunteers. From the coronary sinus effluent, samples were taken for the determination of 6-keto prostaglandin F1 alpha, prostaglandin E2, creatine phosphokinase, and lactate dehydrogenase, respectively. Hemodynamic parameters were measured continuously for 150 minutes after the start. After 15 minutes of reperfusion, the Langendorff-mode was switched to the working heart model. After hearts failed to pump against the afterload column, experiments were terminated, and tissue sections were taken for electron microscopy. RESULTS: Groups A and C showed superior cardiac performance as measured by stroke work index (SWI) that exceeded group B by 2.5 to 3 times (p < 0.05). In all three groups the SWI slowly decreased during perfusion. In group B, SWI decreased to a minimum as early as 90 minutes after the start. In all groups, 6-keto prostaglandin F1 alpha and prostaglandin E2 as indicators of endothelial cell activation increased. In group B, however, the levels exceeded those of groups A and C by six and nine times, respectively (p < 0.05). As markers of myocardial damage, creatine phosphokinase and lactate dehydrogenase increased in all groups. But again levels in group B exceeded those of groups A and C by four to five times (p < 0.05). Electron microscopy revealed single cell necrosis in group B, whereas groups A and C showed interstitial edema only. CONCLUSIONS: Our experiments indicate a crucial role of DAF in preventing rejection in discordant species combinations. Transgenic human DAF seems to inhibit successfully complement-mediated damage to the endothelial cell, thus preventing endothelial activation and consequently myocardial damage. Transgenic human DAF makes a discordant species (pig) function as a concordant species, that is, hyperacute rejection does not occur.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Prevention of hyperacute rejection by human decay accelerating factor in xenogeneic perfused working hearts.

As a potential source of organs for xenotransplantation, pigs that are transgenic for human decay accelerating factor (DAF) have been bred in order to overcome hyperacute rejection. We investigated the protective effect of human DAF in a porcine working heart model perfused by human blood. Hearts of normal landrace pits served as controls. The following parameters were measured: stroke work index, coronary flow and arteriovenous oxygen consumption, 6-keto prostaglandin F1alpha and prostaglandin E2 as markers of endothelial cell activation; creatine phosphokinase and lactate dehydrogenase for evaluation of the extent of myocardial damage; TNFalpha and IL-6 as markers of mononuclear cell activation. Histological and ultrastructural investigations from myocardial tissue sections were done at the end of perfusion. Human (h) DAF appeared to inhibit complement-mediated endothelial cell activation of transgenic pig hearts successfully. This was in contrast to landrace pig hearts, which had a sixfold increase of prostaglandin levels during perfusion with human blood. The cardiac weight increase during perfusion time due to interstitial edema tended to be less in the hDAF group. Myocardial damage was minimal in transgenic hearts, whereas normal pig hearts produced a threefold increase of creatine phosphokinase and lactate dehydrogenase levels. In these hearts, electron microscopy revealed single cell necrosis of myocytes and vacuolization of mitochondria with cristae rupture. According to the results obtained in the working heart model, the breeding of pigs that are transgenic for hDAF represents a promising step to making heart xenotransplantation a clinical reality in the future.

Acute Disease↗
PubMed1991

[Comparison of the hemodynamic effect of enoximone and dopamine in patients after coronary bypass operation].

The efficacy of acute hemodynamic support with intravenous enoximone (n = 10), (2 x bolus 0.5 mg/kg, infusion 5.0 mcg/kg/min), dopamine (n = 10), (3-4.0 mcg/kg/min) over a 18-h period was investigated in patients to be weaned off cardio-pulmonary bypass (CPB) (placebo-controlled trial). Under steady-state conditions enoximone produced a substantial increase in cardiac index (20.6 +/- 1.7%), but no change in heart rate. The improvement in cardiac index with time until constant values were reached (6 h) was not directly paralleled by the plasma concentration of enoximone. Pharmacodynamically relevant concentrations were already present after 1 h of infusion (480 +/- 68 ng/ml) and were comparable with the value determined after 6 h (442 +/- 31 ng/ml). After 18 h of infusion, plasma concentration had reached 742 +/- 47 ng/ml without a further improvement in cardiac function. The augmentation of stroke volume index (23.3 +/- 2.5%) occurred concomitant with a decrease in systemic vascular resistance (-23.1 +/- 0.6%), obviously due to a decrease in diastolic arterial pressure (-12.0 +/- 3.8%). The pulmonary capillary wedge pressure remained unaffected, and there was only a slight decrease in pulmonary vascular resistance (-9.3 +/- 3.2%). During enoximone, as well as dopamine infusion, an increase (10 +/- 3.1 and 9 +/- 1.8%) in right atrial pressure was observed in contrast to the untreated control group. This is contradictory to the described drugs effect in patients suffering from congestive heart failure. In a concentration usually not causing cardioacceleration, dopamine was of minor hemodynamic support in the post-CPB period.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗