Search

The article presents abstracts of the research papers presented at the 23th Congress on Clinical Hemorheology and Microcirculation of the German Society, held in Dresden, Germany, on 4-6 November 2004. A research paper titled "Contribution of Rho-Kinase to Basal Vascular Tone," by E. Bussemaker, F. Pistrosch, P. Gross and J. Passauer, tested the role of Rho-kinase for the regulation of the peripheral vascular tone in healthy, normotensive volunteers. Another paper titled "The Nature of EDHF in the Renal Vasculature," by E. Bussemaker, P. Gross, and I. Fleming, studied the nature of EDHF (endothelium-derived hyperpolarizing factor) in the human interlobar renal artery.

BACKGROUND Transfemoral aortic valve replacement (TAVR) is the standard treatment for elderly patients with aortic valve stenosis. Although safe and well-established, there is a risk of intraprocedural hemodynamic instability and silent cerebral embolism, which can lead to a decline in neurocognitive function and dementia. In clinical practice, comprehensive cognitive testing is difficult to perform. AI-assisted digital applications may help to optimize diagnosis and monitoring. METHODS Neurocognitive function was assessed by validated psychometric tests using "Δelta -App", which uses artificial intelligence and computational linguistic methods for extraction and analysis. Memory function was assessed using the 'Consortium to Establish a Registry for Alzheimer's Disease' (CERAD) word list and digit span task (DST) before TAVR and before hospital discharge. The study is registered in the German Register of Clinical Trials (https://drks.de/search/de/trial/DRKS00020813). RESULTS From October 2020 until March 2022, 141 patients were enrolled at University Hospital Heart Centre Brandenburg. Mean age was 81 ± 6 years, 42.6% were women. Time between the pre- and post-interventional test was on average 6 ± 3 days. Memory function before TAVR was found to be below average in relation to age and educational level. The pre-post TAVR comparison showed significant improvements in the wordlist repeat, P < 0.001 and wordlist recall test of CERAD, P < 0.001. There were no changes in the digital span test. CONCLUSIONS Despite impaired preoperative memory function before TAVR, no global negative effect on memory function after TVAR was detected. The improvements shown in the word list test should be interpreted as usual learning effects in this task. [ABSTRACT FROM AUTHOR]

Percutaneous coronary intervention of complex stenoses is becoming more and more of an alternative to coronary bypass surgery. Nevertheless, complications can occur and lead to the need for circulatory support and/or emergency surgery. Circulatory support devices like the intra-aortic balloon pump showed only low benefit in patients' outcome. Devices with higher cardiac output necessitate more complex implantation procedures. We report the case of the first successful use of a transfemoral pulsatile ventricular assist device with up to 2 l additional cardiac output during high-risk percutaneous coronary intervention in a 74-year-old man with complex stenosis. The device was safe and feasible during coronary intervention in its use. Its beneficial effect on hemodynamics and patients' outcome has to be evaluated in larger multicenter studies. [ABSTRACT FROM AUTHOR]

Background: Management of cardiac surgery patients is a very standardized procedure in respective local institutions. Yet only very limited evidence exists concerning optimal indication, safety and efficacy of hemodynamic monitoring catecholamine and fluid therapy. Methods: Between April and May 2013, all 81 German anaesthesia departments involved in cardiac surgery care were asked to participate in a questionnaire addressing the institutional specific current practice in hemodynamic monitoring, catecholamine and volume therapy. Results: 51 (63%) questionnaires were completed and returned. All participating centers used basic hemodynamic monitoring (i.e. invasive arterial blood pressure and central venous pressure), supplemented by transesophageal echocardiography. Pulmonary arterial catheter and calibrated trend monitoring devices were also routinely available. In contrast, non-calibrated trend monitoring and esophageal doppler ultrasound devices were not commonly in use. Cerebral oximetry is increasingly emerging, but lacks clear indications. The majority of patients undergoing cardiac surgery, especially in university hospitals, required catecholamines during perioperative care, In case of low cardiac output syndrome, dobutamine (32%), epinephrine (30%) or phosphodiesterase inhibitors (8%) were first choice. In case of hypotension following vasoplegia, norepinephrine (96%) represented the most common catecholamine. 88% of the participating centers reported regular use of colloid fluids, with hydroxyethyl starches (HES) being first choice (64%). Conclusions: Choice of hemodynamic monitoring is homogenous throughout German centers treating cardiac surgery patients. Norepinephrine is the first line catecholamine in cases of decrease in peripheral vascular resistance. However, catecholamine choice for low cardiac output syndrome varies considerably. HES was the primary colloid used for fluid resuscitation. After conduct of this survey, HES use was restricted by European regulatory authorities in critically ill patients and should only be considered as second-line fluid in surgical patients without renal impairment or severe coagulopathy. Large clinical studies addressing catecholamine and fluid therapy in cardiac surgery patients are lacking. [ABSTRACT FROM AUTHOR]

The article presents a study on the use of an extracorporeal life support (ECLS) system for optimized blood pressure and flow to improve neurological recovery. The study shows big improvement in survival after 15 minutes of normothermic cardiac arrest. The results of the study supports the hypothesis that using an ECLS for pressure- and flow-controlled circulation after circulatory arrest is superior to conventional CPR.

The article presents the schedules of the presentations, discussions and sessions at the 16th meeting of the European Society of Neurosonology and Cerebral Hemodynamics on May 20-23, 2011 in Munich, Germany.

To date, transcatheter valve implantation is limited to the replacement of pulmonary and aortic valves. The aim of this study was to analyze a valved stent for minimally invasive implantation in the mitral position. A self-expanding mitral valved stent was designed for transapical implantation. Thirty pigs underwent off-pump mitral valved stent implantation with follow-up times of 60 minutes (n == 17) and seven days (n == 13). Transesophageal echocardiography and computed tomography were used to evaluate stent function and positioning. After valved stent deployment, accurate adjustment of the intra-annular position reduced paravalvular leakage in all animals. Accurate positioning was established in all but five animals. The average mean transvalvular gradient across the mitral valve and the left ventricular outflow tract recorded immediately after deployment, six hours and one week were 1.85 ±± 0.95 mmHg, 3.45 ±± 1.65 mmHg, 4.15 ±± 2.3 mmHg and 1.35 ±± 1.35 mmHg, 1.45 ±± 0.7 mmHg, 1.9 ±± 0.65 mmHg, respectively. No valved stent migration, embolization, systolic anterior movement or left ventricular outflow tract obstruction was observed. The mitral valved stent can be deployed in a reproducible manner to achieve reliable stent stability, minimal gradients across the left ventricular outflow tract and adequate stent function in acute and short term experimental settings. [ABSTRACT FROM AUTHOR]

There is still a lack of quantitative information concerning optimal blood flow in the aorta and in the carotid arteries during extracorporeal circulation (ECC). Problems are not only based on the location of the aortic cannula, they are furthermore associated with the cannula design itself and the effects on blood cells and aortic wall shear stresses. We simulated a two-phase fluid flow induced by different cannulas in the ascending aorta during ECC. Three commercially available cannulas were examined according to their influence on red blood cells (RBC). Additionally, mass flow in the carotid vessels and wall shear stresses acting on the aortic wall were evaluated. A constant volume flow of blood (3.4 L/min) was applied. Numerical results demonstrate a strong relation between the mass flow rate in the carotid vessels and the geometry of the aortic outflow cannula. RBC distributions both in the aorta and the carotid vessels changed depending on cannula geometry. Maximum blood velocities, shear stresses on the aortic wall, and the fluid mechanical load acting on RBCs varied depending on each cannula design. This numerical approach demonstrates the significant influence of the cannula design on the distribution of RBCs in the carotid vessels during ECC. [ABSTRACT FROM AUTHOR]

Information on the topics discussed by the author at the 14th European Conference for Clinical Hemorheology and Microcirculation held in Dresden, Germany is presented. The author talks about several studies on smoking, neonatal and foetal, haemorheology and haemodynamics, mammalian, and mechanism of rouleaux formation. Furthermore, he also cites the comparability of haematology and haemorheology.