Clinical Hemorheology and Microcirculation - Volume 64, issue 3

Authors: Jung, F. | Rampling, M.

Article Type: Editorial

DOI: 10.3233/CH-168108

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 251-254, 2016

Authors: Gori, Tommaso | von Henning, Urs | Muxel, Selina | Schaefer, Sarina | Fasola, Federica | Vosseler, Marcus | Schnorbus, Boris | Binder, Harald | Parker, John D. | Münzel, Thomas

Article Type: Research Article

Abstract: INTRODUCTION: Flow-mediated dilation (FMD) quantifies endothelium-dependent vasomotor responses to short-term increases in blood flow. Low-flow mediated vasoconstriction (L-FMC) has been more recently introduced as additional measure of endothelial function, and its relationship with changes in blood flow, cardiovascular risk factors and FMD ha∧ s been less well characterized. MATERIALS AND METHODS: We evaluated radial artery FMD and L-FMC along with the changes in blood flow and shear rate/stress in 584 patients with known or suspected coronary artery disease (72.9% men, mean age 67+/–11 years). Baseline blood flow and shear rate showed a modest association with radial artery …FMD and L-FMC (R2  = 0.04 and R2  = 0.02, P  < 0.0001). Resting diameter showed a stronger association with FMD but not with L-FMC (R2  = 0.11, P  < 0.0001 and R2  = 0.005, P  = 0.09). Analysis with generalized additive models showed that age, sex and presence and extent of coronary artery disease were strongly related to both endothelial function measures (P  < 0.001 for both), but they explained only 12.4% and 10.1% of the variance in L-FMC and FMD. When the corresponding changes in blood flow were added to these statistical models, the % of variance explained raised to 20.4% and 17.7% for L-FMC and FMD. L-FMC was a strong predictor of FMD even after correction for the changes in blood flow. DISCUSSION: Changes in blood flow are the most important determinants of both L-FMC and FMD. These observations support the concept that both FMD and L-FMC measure endothelium-dependent, shear-induced, vasomotion. Show more

Keywords: Endothelium/vascular type/nitric oxide, pathophysiology, coronary circulation

DOI: 10.3233/CH-168102

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 255-266, 2016

Authors: Orphal, Dörte | Gori, Tommaso

Article Type: Research Article

Abstract: A number of studies consistently report higher rates of all clinical outcomes including postinfarction mortality, need for repeat revascularization, and reinfarction in women with cardiovascular diseases than in men. As well, the gender gap in the prevalence of cardiovascular diseases decreases progressively with increasing age. Yet, the diagnosis and treatment of these diseases differ between genders and women remain underdiagnosed for coronary heart disease. In a recent retrospective analysis we showed that, along with vessel under study and age, gender is a determinant of adenosine responses during studies of fractional flow reserve, an effect that was probably due to differences …in microvascular function and that influenced the interpretation of fractional flow reserve data. These data demonstrate that not only the clinical presentation is different, but also the diagnostic approach to coronary artery disease might differ between sexes. A gap still exists in the understanding of the mechanisms, awareness, and treatment of coronary artery disease in women, but also, as we show, in the application of diagnostic modalities that are well established in men. Show more

Keywords: Microvascular function, coronary, sex

DOI: 10.3233/CH-168103

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 267-272, 2016

Authors: Ullrich, Helen | Gori, Tommaso

Article Type: Research Article

Abstract: Triple anticoagulant therapy is necessary in patients who are at increased risk for both arterial (in stent) and venous thrombosis, or have atrial fibrillation. Triple therapy however also poses a very high risk for bleeding events, particularly because this subset of patients is particularly frail due to the high incidence of comorbidities and advanced age. Very little randomized studies have tested the impact of the many possible combinations of anticoagulant/antiaggregant drugs, and surveys among practicing physicians show that the use of off-label therapies is very common. In a recent survey from our group, we observed that physicians are very divided …in terms of what therapy should be recommended to patients with indication to anticoagulation and with a history of stenting. The use of novel anticoagulants was as frequent as that of vitamin K antagonists, and the duration of triple therapy was very variable. While these data probably show that decisions are usually taken on an individual basis, considering the patient’s risk of ischemia and hemorrhagic events, much of this variability probably depends on the fact that, failing randomized trials, guidelines in this area are relatively less specific than in other ones. Show more

Keywords: Antiplatelet therapy, coronary stenting, anticoagulants

DOI: 10.3233/CH-168104

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 273-278, 2016

Authors: Kiouptsi, Klytaimnistra | Reinhardt, Christoph

Article Type: Research Article

Abstract: The plasmatic coagulation system is tightly controlled by natural anticoagulant mechanisms, preventing thrombosis to ensure the supply of tissues with oxygen and nutrients without provoking susceptibility to bleeding diatheses. The membrane receptor tissue factor (TF) is the principal initiator of coagulation, forming a high affinity complex with coagulation factor VIIa, thus catalyzing quantitative formation of the coagulation factor Xa. While it has been well-established that the TF-VIIa complex is efficiently blocked by factor Xa associated with tissue factor pathway inhibitor (TFPI), it was uncovered during the last decade that TF contains an intramolecular allosteric disulfide, which is prone to reduction …and is crucial for TF’s procoagulant and prothrombotic function. The compromised integrity of the allosteric TF disulfide pair Cys186/Cys209 was demonstrated to be responsible for the cryptic nature of TF procoagulant activity on monocytes and other cell types as well as in mouse thrombosis models. Cell surface associated protein disulfide-isomerases (PDI) were identified as activators of cryptic tissue factor. Here, we review this current concept of TF de-encryption by PDI oxidoreductases that have become interesting targets for the development of new antithrombotic treatment strategies. Show more

Keywords: Thrombosis, tissue factor, protein disulfide-isomerase, PDI

DOI: 10.3233/CH-168106

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 279-286, 2016

Authors: Lamby, P. | Jung, F. | Falter, J. | Mrowietz, C. | Graf, S. | Schellenberg, L. | Platz Batista da Silva, N. | Prantl, L. | Franke, R.P. | Jung, E.M.

Article Type: Research Article

Abstract: BACKGROUND: Intra-arterial administration of radiographic contrast media (CM) is discussed to impair renal perfusion. The pathogenesis of contrast-induced Nephropathy (CIN) is still not clarified. OBJECTIVE: This trial was performed to prove the effects of two CM with different molecular structure on renal perfusion. METHODS: A prospective, randomized study on 16 pigs was designed to compare the outcome after application of a low-osmolar iodinated CM (770 mOsm/kg H2 O – Group1) and an iso-osmolar iodinated CM (290 mOsm/kg H2 o – Group2). Color Coded Doppler Sonography (LOGIQ E9, GE, Milwaukee, USA) was applied for measuring the Renal …Resistive Index (RRI) before and after the first, fifth, and tenth bolus of CM. Statistics was performed using analysis of variance for repeated measurements with the Factor “CM”. RESULTS: All flow spectra were documented free of artifacts and Peak Systolic Velocity (PSV), Enddiastolic Velocity (EDV) and RRI respectively could be calculated. Mean PSV in Group 1 led to a decrease while in Group 2 PSV showed a significant increase after CM (p  = 0,042). The course of the mean EDV in both groups deferred accordingly (p  = 0,033). Mean RRI over time significantly deferred in both groups (p  = 0,001). It showed a biphasic course in Group 2 and a decrease over time in Group 2. CONCLUSION: While iso-osmolar CM induced an increase of PSV and EDV together with a decrease of RRI, low-osmolar CM could not show this effect or rather led to the opposite. Show more

Keywords: Renal perfusion, radiographic contrast media, contrast agent, CCDS, color coded Doppler sonography, contrast-induced Nephropathy, CIN

DOI: 10.3233/CH-168110

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 287-295, 2016

Authors: Gerk, U. | Mrowietz, C. | Sternitzky, R. | Franke, R.P. | Spitzer, S.G. | Jung, F.

Article Type: Research Article

Abstract: Radiographic contrast media (RCM) can initiate microcirculatory disorders. This study was performed to investigate effects of Ioxaglate on the cutaneous microcirculation. The investigation was carried out as prospective randomized double-blind comparison in parallel-group design on two groups of n  = 10 patients each who had to undergo a diagnostic coronary angiography. The confirmatory parameter of the study was mean erythrocyte capillary velocity [v RBC in mm/sec]. V RBC in the ipsilateral nail-fold capillaries was recorded continuously for 3 min before and 6 min after injection of RCM or isotonic saline solution in the A. axillaris respectively, and was evaluated off-line. …V RBC in nailfold capillaries was found to be decreased by Ioxaglate by 34% 150 seconds after injection, while isotonic NaCl solution immediately induced a slight increase of 14%. Show more

Keywords: Cutaneous microcirculation, Ioxaglate, coronary artery disease

DOI: 10.3233/CH-168101

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 297-304, 2016

Authors: Kehrer, Andreas | Lamby, Philipp | Miranda, Benjamin H. | Prantl, Lukas | Dolderer, Juergen H.

Article Type: Research Article

Abstract: BACKGROUND AND OBJECTIVES: Radical excisions of the rectum often result in large perineal and intrapelvic defects. Compromised wound healing can delay adjuvant therapies and limit the patient’s prognosis. With current treatment, integrity of the abdominal wall may be maintained. The defect geometry is unique and requires extensive volume for reconstruction. This study describes the surgical technique and reports clinical outcomes of fasciocutaneous posterior thigh flaps as preliminary data for this indication. METHODS: Thirteen posterior thigh flaps were used in eleven patients between 2013–2015. Patients were prospectively followed-up for the pursposes of this case series. Flap dimensions and …volume were measured in two representative cases. The surgical technique is described in detail. RESULTS: Dead space occlusion was achieved in 100% of cases. No intestinal herniation was detected. Vaginal wall defects were concurrently reconstructed in two patients. Total flap volume was calculated as 315–360 cm3 . The fasciocutaneous flaps were easy to harvest, versatile to manipulate and did not result in significant function deficits. CONCLUSIONS: In contrast to classic Vertical Rectus Abdominis Muscle (VRAM) flaps, the posterior thigh flaps preserve abdominal wall function and should be considered as a reliable alternative option in reconstruction of intrapelvic defects including neighboring organs. Future studies of larger patient series should be executed to verify our findings and determine the optimal point in time for reconstruction. Show more

Keywords: Rectum resection, rectum extirpation, pelvic defect, perineal defect, posterior thigh flap, VRAM flap

DOI: 10.3233/CH-168105

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 305-318, 2016

Authors: Mandlik, V. | Kehrer, A. | Jiga, L. | Hoinoiu, B. | Ionac, M. | Jung, F. | Staudenmaier, R. | Prantl, L.

Article Type: Research Article

Abstract: BACKGROUND: The technique of flap-prefabrication has been successfully established in tissue engineering: missing intrinsic vascularisation of engineered tissue can be generated in vivo by microsurgical vesselloop construction. It is possible to move engineered tissue into a defect with microsurgery. In the literature, the combination of engineered tissue covered with skin is not widely reported. OBJECTIVE: Aim of this study was to establish a model to investigate scaffold prefabrication with full thickness skin graft coverage with subsequent free tissue transfer. METHODS: 8 Wistar rats were operated in 2 separate steps: 1) after creating an arteriovenous …loop with the femoral vessels, a porous scaffold was placed on the loop and covered with an inguinally based skin flap. A control was implanted without loop into the contralateral groin. 2) 6 weeks later the prefabricated composite flaps were microsurgically transferred to the cervical region. Skin-island monitoring was performed with Laser Doppler-scanner after the transfer. RESULTS: Continuous loss of the skin islands was observed within 72 hours. Complications included wound-dehiscence, thrombosis and death from anaesthesia; in spite of consistent loop viability. CONCLUSION: Evaluation showed that modifications are necessary to maintain the skin-island cove. Show more

Keywords: Composite tissue, tissue engineering applications, animal models, enabling technologies, angiogenesis and vasculogenesis, fundamentals of tissue engineering

DOI: 10.3233/CH-168120

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 319-331, 2016

Authors: Bachleitner, K. | Blank, B. | Klein, S. | Geis, S. | Aung, T. | Prantl, L. | Dolderer, J.H.

Article Type: Research Article

Abstract: BACKGROUND: The reconstruction of metacarpal- and interphalangeal joints after severe hand injuries has been proven to be challenging. Commonly used procedures like arthrodesis, amputation or ray resection of the finger compromise the functionality of the injured finger. Especially for young patients, the restoration of all functions of the fingers is a priority. Local tissue transfers for finger joint reconstructions is not an option due to inacceptable donor site morbidity; microsurgical tissue transfers in terms of free toe joint transfers have proven to be a valuable method. METHODS: We present the case of a patient who suffered an …excessive injury from a circular saw to his dominant hand. The MCP Joints of D2-D4 were fully destroyed, along with the PIP joint of a subtotally amputated D4. Arteries, nerves and tendons could be coapted directly, while primarily reconstructing of the finger joints was impossible. To ensure a possible regain of full functionality, two coherent joints, the MTP and the PIP of one toe, were transferred to the ring finger as a single transplant, reconstructing the MCP and the PIP joints of the injured finger in a one step procedure. Additionally the MCP joint of the D2 was reconstructed by the use of a free PIP-joint transfer, further the MCP joint of the D3 was replaced by an MCP endoprosthesis. RESULTS: After a follow up of 3 years the patient displayed full function of his dominant hand including sensitivity, and has gone back to manual work without limitations. The result was cosmetically acceptable and the donor site defect was easily being tolerated by the patient who is playing soccer in the regional soccer league. CONCLUSION: Free double toe joint transfer has been proven feasible in this patient. While transferring a single toe joint to reconstruct a finger joint is a well-established method, our review of the latest literature showed no case of a free transfer of two coherent joints and three transplanted joints in one hand. The applied microsurgical technique should be considered by microsurgically trained hand surgeons for the treatment of comparable severe hand injuries. In comparison to the most common procedures described for the repair and reconstruction of severely injured finger joints this method showed superior results. Show more

Keywords: Free vascularized toe joint transfer, coherent double toe joint transfer, PIP-MCP-Joint-Defect, microsurgery, complex hand surgery

DOI: 10.3233/CH-168100

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 333-344, 2016

Authors: Braune, S. | Basu, S. | Kratz, K. | Johansson, J. Bäckemo | Reinthaler, M. | Lendlein, A. | Jung, F.

Article Type: Research Article

Abstract: Polymer-based microparticles are applied as non-thrombogenic or thrombogenic materials in a wide variety of intra- or extra-corporeal medical devices. As demanded by the regulatory agencies, the hemocompatibility of these blood contacting biomaterials has to be evaluated in vitro to ensure that the particle systems appropriately fulfill the envisioned function without causing undesired events such as thrombosis or inflammation. Currently described in vitro assays for hemocompatibility testing of particles comprise tests with different single cell types (e.g. erythrocytes or leukocytes), varying concentrations/dilutions of the used blood cells or whole blood, which are not standardized. Here, we report about …an in vitro dynamic test system for studying the hemocompatibility of polymeric microparticles utilizing fresh human whole blood from apparently healthy subjects, collected and processed under standardized conditions. Spherical poly(ether imide) microparticles with an average diameter of 140±30 μm were utilized as model systems. Reported as candidate materials for the removal of uremic toxins, these microparticles are anticipated to facilitate optimal flow conditions in a dialyzer with minimal backflow and blood cell damage. Pristine (PEI) and potassium hydroxide (PEI-KOH) functionalized microparticles exhibited similarly nanoporous surfaces (PEI: ØExternal pore  = 90±60 nm; PEI-KOH ØExternal pore  = 150±130 nm) but varying water wettabilities (PEI: θ adv  = 112±10° PEI-KOH θ adv  = 60±2°). The nanoporosity of the microparticle surfaces allows the exchange of toxic solutes from blood towards the interconnective pores in the particle core, while an immigration of the substantially larger blood cells is inhibited. Sterilized PEI microparticles were incorporated –air-free –in a syringe-based test system and exposed to whole blood for 60 minutes under gentle agitation. Thereafter, thrombi formation on the particles surfaces were analyzed microscopically. In the collected whole blood the non-adherent/circulating single blood cells were quantified via a differentiated complete blood cell count and the activation of platelets (P-Selectin expression, secretion and release), platelet function (PFA100 closure time) as well as thrombin formation (thrombin-antithrombin-complex) was analyzed. Free hemoglobin (HGB) levels were quantified as a measure of hemolysis. Microscopic evaluation revealed thrombi formation and particle aggregates for all tested microparticles. Reduction of circulating blood cells differed significantly between the particle types. Particularly, platelet and monocyte counts decreased up to 50% compared to the control (syringe filled with whole blood but without microparticles). In accordance, platelet activation, thrombin levels and degrees of hemolysis were clearly elevated in the particle loaded test systems and allowed a differentiation between the particle types. Increased PFA100 closure times (as activating agent a combination of collagen/ADP was used) indicated a similarly reduced ability of platelets to adhere and form stable aggregates independent from the particle type tested. This observation is most probably a consequence of the strong thrombus formation in the test system, which is associated with a reduction of the circulating blood cells. The reported in vitro dynamic whole blood test system allowed the sensitive analysis of the hemocompatibility of polymer-based microparticles and was successfully validated for porous PEI microparticles with different water wettabilities. Beyond the qualitative and quantitative analysis of cell-material interactions, the test also allowed the functional evaluation of platelets in whole blood. Show more

Keywords: Biomaterial, polymer, microparticle, thrombogenicity, hemocompatibility, dynamic in-vitro test

DOI: 10.3233/CH-168114

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 345-353, 2016

Authors: Li, Zhengdong | Wang, Weiwei | Kratz, Karl | Küchler, Judit | Xu, Xun | Zou, Jie | Deng, Zijun | Sun, Xianlei | Gossen, Manfred | Ma, Nan | Lendlein, Andreas

Article Type: Research Article

Abstract: Induced pluripotent stem cells (iPSCs) own the capacity to develop into all cell types of the adult body, presenting high potential in regenerative medicine. Regulating and controlling the differentiation of iPSCs using the surface topographic cues of biomaterials is a promising and safe approach to enhance their therapeutic efficacy. In this study, we tested the effects of surface roughness on differentiation of human iPSCs into neural progenitor cells and dopaminergic neuron cells using polystyrene with different roughness (R0: flat surface; R1: rough surface, Rq ∼ 6 μm; R2: rough surface, Rq ∼ 38 μm). Neural differentiation of human …iPSCs could be influenced by surface roughness. Up-regulated neuronal markers were found in cells on rough surface, as examined by real-time PCR and immunostaining. Particularly, the R1 surface significantly improved the neuronal marker expression, as compared to R0 and R2 surface. This study demonstrates the significance of surface roughness, depending on the roughness level, in promoting differentiation of human iPSCs towards the neuronal lineage. Our study suggests the potential applications of surface roughness in iPSCs based treatment of neural disorder diseases, and highlights the importance of design and development of biomaterials with effective surface structures to regulate stem cells. Show more

Keywords: Human iPSCs, roughness, neural differentiation, regenerative medicine

DOI: 10.3233/CH-168121

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 355-366, 2016

Authors: Xu, Xun | Wang, Weiwei | Li, Zhengdong | Kratz, Karl | Ma, Nan | Lendlein, Andreas

Article Type: Research Article

Abstract: The permanent loss of cardiomyocytes may lead to the irreversible damage of myocardium in cardiovascular diseases. The induced pluripotent stem cells (iPSCs) with the capacity of differentiation into a variety of cell types including cardiomyocytes showed high potential for efficient heart regeneration. The iPSCs and iPSC-derived embryoid bodies (EBs) as well as the differentiated cardiomyocytes are highly sensitive to the biophysical cues of their microenvironment, and accordingly their behavior and function can be largely modulated by microstructure of the cell culture surface. In this study, we investigated the regulatory effect of microscale roughness on both cardiomyogenesis and secretion of EBs …using poly(ether imide) (PEI) cell culture inserts with different levels of bottom roughness (R0: flat surface; R1: rough surface, Rq ∼ 4 μm; R2: rough surface, Rq ∼ 23 μm). The proliferation rate and cardiomyogenesis of EBs increased with the increase of surface roughness. The EB secretome derived from R2 surface remarkably enhanced the in vitro new vessel formation of endothelial cells, as compared to those from R0 and R1. These findings highlight the potential to improve the iPSC/EB-based restoration of cardiovascular function via microstructured biomaterials. Show more

Keywords: Microroughness, induced pluripotent stem cells, embryoid body, cardiomyogenesis, secretome

DOI: 10.3233/CH-168107

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 367-382, 2016

Authors: Krüger-Genge, Anne | Jung, Friedrich | Fuhrmann, Rosemarie | Franke, Ralf-Peter

Article Type: Research Article

Abstract: BACKGROUND: Endothelial cells (EC) in vivo are strongly influenced by changes of the milieu exterieur. Under pathological conditions EC can become activated e.g. in hypoxic areas or during sepsis. In general, the endothelialization of implant materials is evaluated in vitro under physiological conditions. Though, in patients who receive implant materials pathological conditions are often present. An open question is therefore, how ECs seeded on a body foreign substrate behave in a pathologic microenvironment. In this in vitro study a microenvironment was created mimicking the conditions present in septic patients. To simulate this situation in vitro , …serum of patients with septic shock was added to the culture medium of EC cultured on glass. The samples were sheared in a cone-plate rheometer (shear rate of 6 dyn/cm2 ) with subsequent analysis of the morphology, the microfilament organization and the shear resistance and compared to control cultures of EC without shock serum supplementation. Aim of the study was to investigate whether this in vitro model provides information about the functionality of an EC monolayer on a body foreign surface under pathological conditions. RESULTS: Septic conditions induced severe changes of the morphology of the adherent cells: there was a strong induction of stress fibers. In addition, lots of cells or cell groups were detached visible as denuded areas in the EC monolayer. After shear stress exposure only 28.7% of EC seeded in cell medium supplemented with serum of septic patients remained adherent (control cells: 96.8%). CONCLUSION: The study demonstrates that the microenvironment is of extreme importance for the behavior of EC and that in vivo pathologies can be simulated in vitro . This opens the possibility to evaluate new implant materials under physiological but more important also under certain pathological conditions - simulating the implant size and the disease of the host. Show more

Keywords: Endothelial cells, in vitro, sepsis, shear rate

DOI: 10.3233/CH-168111

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 383-389, 2016

Authors: Kaessmeyer, S. | Sehl, J. | Khiao In, M. | Hiebl, B. | Merle, R. | Jung, F. | Franke, R.P. | Plendl, J.

Article Type: Research Article

Abstract: INTRODUCTION: Clinical complications like thrombosis or anaphylaxis have been described to go along with the intra-venous or intra-arterial injection of iodinated contrast media (CM). It has been suggested that the administration of CM affects rheological parameters and thereby causes reduced blood velocity in microvessels. In vitro studies revealed significant buckling of endothelial cells after exposure to CM reducing the lumen of vessels. The aim of this study was to test the influence of CM on three-dimensional microvascular tubules with open lumina within an organotypic soft-tissue co-culture assay in vitro . This model, which is based on the co-culture …of endothelial cells and fibroblasts, allows the analysis and quantitation of different parameters of microvascular endothelial capillary structures. MATERIAL AND METHODS: Human dermal fibroblasts and human dermal microvascular endothelial cells were co-cultured for 10 days. Fibroblasts were adapted to the endothelial cell medium before co-culture and allowed to proliferate as well as produce extracellular matrix. The co-cultures were exposed to three different CM, i.e., Iomeprol (Imeron 400MCT), Iodixanol (Visipaque 320) or Iohexol (Accupaque 350) for 1.5 minutes or 5.0 minutes, respectively. For this, a mixture of CM and cell culture medium in a ratio of 30% CM by volume was prepared. After fixation in methanol/acetone, the endothelial cells were immunolabeled with the endothelial marker anti-CD31 and the tubular structures were assessed morphometrically. RESULTS: In the organotypic soft-tissue co-cultures with fibroblasts, the endothelial cells developed three-dimensional capillary-like structures which expanded via sprouting branches. After incubation with the different CM, the numbers of endothelial tubes (p  = 0.001) and their lengths (p  = 0.003) were significantly lower after the 5 minutes incubation time, when compared to the 1.5 minutes incubation time. The tubular diameters were significantly reduced after 5 minutes (p  < 0.001), when compared to the 1.5 minutes incubation duration. Interestingly, Iomeprol and Iodixanol induced an elongation of the tubular branches during incubation duration of 1.5 minutes (p  = 0.015). However, after 5 minutes incubation, the tubular branches were drastically shorter in the presence of Iomeprol and Iodixanol than the tubular branches of the control (p  = 0.007). SUMMARY AND CONCLUSION: All CM exerted a negative effect on the parameters of in vitro blood vessel development. Show more

Keywords: Soft-tissue co-cultures, microvascular endothelial tubes, angiogenesis, Iomeprol, Iodixanol, Iohexol, contrast media

DOI: 10.3233/CH-168119

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 391-402, 2016

Authors: Hanke, Alexander | Prantl, Lukas | Wenzel, Carina | Nerlich, Michael | Brockhoff, Gero | Loibl, Markus | Gehmert, Sebastian

Article Type: Research Article

Abstract: INTRODUCTION: The stem cell rich Stromal Vascular Fraction (SVF) can be harvested by processing lipo-aspirate or fat tissue with an enzymatic digestion followed by centrifugation. To date neither a standardised extraction method for SVF nor a generally admitted protocol for cell application in patients exists. A novel commercially available semi-automated device for the extraction of SVF promises sterility, consistent results and usability in the clinical routine. The aim of this work was to compare the quantity and quality of the SVF between the new system and an established manual laboratory method. MATERIAL AND METHODS: SVF was extracted …from lipo-aspirate both by a prototype of the semi-automated UNiStation™ (NeoGenesis, Seoul, Korea) and by hand preparation with common laboratory equipment. Cell composition of the SVF was characterized by multi-parametric flow-cytometry (FACSCanto-II, BD Biosciences). The total cell number (quantity) of the SVF was determined as well the percentage of cells expressing the stem cell marker CD34, the leucocyte marker CD45 and the marker CD271 for highly proliferative stem cells (quality). RESULTS: Lipo-aspirate obtained from six patients was processed with both the novel device (d) and the hand preparation (h) which always resulted in a macroscopically visible SVF. However, there was a tendency of a fewer cell yield per gram of used lipo-aspirate with the device (d: 1.1×105 ±1.1×105 vs. h: 2.0×105 ±1.7×105 ; p  = 0.06). Noteworthy, the percentage of CD34+ cells was significantly lower when using the device (d: 57.3% ±23.8% vs. h: 74.1% ±13.4%; p  = 0.02) and CD45+ leukocyte counts tend to be higher when compared to the hand preparation (d: 20.7% ±15.8% vs. h: 9.8% ±7.1%; p  = 0.07). The percentage of highly proliferative CD271+ cells was similar for both methods (d:12.9% ±9.6% vs. h: 13.4% ±11.6%; p  = 0.74) and no differences were found for double positive cells of CD34+ /CD45+ (d: 5.9% ±1.7% vs. h: 1.7% ±1.1%; p  = 0.13), CD34+ /CD271+ (d: 24.1% ±12.0% vs. h: 14.2% ±8.5%; p  = 0.07). DISCUSSION: The semi-automated closed system provides a considerable amount of sterile SVF with high reproducibility. Furthermore, the SVF extracted by both methods showed a similar cell composition which is in accordance with the data from literature. This semi-automated device offers an opportunity to take research and application of the SVF one step further to the clinic. Show more

Keywords: Stromal vascular fraction, lipo-aspirate, adipose tissue, mesenchymal stem cells

DOI: 10.3233/CH-168124

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 403-412, 2016

Authors: Bramhoff, Anja | Giers, Günther | Blessing, Frithjof | Wenzel, Folker

Article Type: Research Article

Abstract: INTRODUCTION: Referring to current standards the quality of an apheresis procedure is estimated by the quantity of collected cells. Nowadays a new kind of quality measurement could be found in the detection of cell volumina. Recent diagnostics have shown that stem cells and platelets – when separated – are likely to appear in a higher volume inside the cell product. Therefore, in this study the question should be discussed wether platelets of higher volume are more likely to be separated than platelets showing a lesser volume. METHODS: Blood samples of three different apheresis procedures could be observed: …allogenic platelet donations (n  = 7) (Trima, Terumo), autologous (n  = 5) and allogenic stem cell donations (n  = 5) (Cobe Spectra, Terumo). To examine the blood samples the Sysmex hematology analyser (XT-2000) has been used. RESULTS: During stem cell apheresis, the volume of the separated platelets was 1.2 fold increased compared to the platelet volume in the peripheral blood before separation. Before apheresis the mean platelet volume in the peripheral blood was found to be 6,21 fl, after apheresis 6,09 fl and inside the platelet concentrate 7,42 fl. The platelet number in the peripheral blood was also significantly decreased (before separation 180.1/nl and after separation 133.5/nl). In the blood products the concentration of platelets was nearly 8 fold higher than in the peripheral blood before separation. CONCLUSION: Overall, the observed apheresis procedures are more likely to separate platelets showing a higher voulme than common in the peripheral blood. This might indicate that not only the amount of separated cells reflects the quality of the apheresis procedure but also that the volume of the separated cells can be used as a parameter for quality assessment. Show more

Keywords: Platelet volume, apheresis procedure, stem cells, thrombocytes, quality assessment

DOI: 10.3233/CH-168109

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 413-424, 2016

Authors: Konschake, Wolfgang | Riebe, Helene | Pediaditi, P. | Haase, Hermann | Jünger, Michael | Lutze, Stine

Article Type: Research Article

Abstract: BACKGROUND: Below knee two-component compression stockings (AD) have revealed as effective for compression treatment of venous leg ulcers. Upto groin, thigh length stocking (AG) may enhance clinical effects, however wear comfort of these stocking may be affected. OBJECTIVE: venous haemodynamic in relation to the length of compression stockings. METHODS: A two-component AD stocking (37 mmHg) and two thigh length stockings (AG 37, with an interface pressure of 37 mmHg; AG 45, with an interface pressure of 45 mmHg) were tested by 16 patients with CVI. Leg volume changes and venous ejection fraction and venous filling …index were measured, whilst quality of life and wear comfort were surveyed by questionnaires. RESULTS: Volume of both the lower limb and the thigh was reduced by AG stockings, whereas AD stockings reduced only the volume of the lower limb and increased thigh volume. Venous hemodynamic, ejection fraction and filling index were improved by AG and AD stockings, AG, however, was superior to AD. Quality of life and comfort of the stockings was assessed as good for AG 37 mmHg, AG 45 mmHg and AD 37 mmHg. CONCLUSIONS: Thigh length two component stockings (AG) were shown to be superior to below knee stocking (AD) with regard to volume reduction and venous hemodynamic, yet wear comfort was not impaired. These results imply that healing of trophic skin changes e.g. ulcers will be faster when thigh length two component stocking will be worn. Show more

Keywords: Chronic venous insufficiency, compression stocking, two-component compression stocking, thigh lengthcompression stocking, below knee compression stocking, venous ejection fraction, venous filling index, leg volume

DOI: 10.3233/CH-168122

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 425-434, 2016

Authors: Haimerl, M. | Poelsterl, S. | Beyer, L.P. | Wiesinger, I. | Nießen, C. | Stroszczynski, C. | Wiggermann, P. | Jung, E.-M.

Article Type: Research Article

Abstract: PURPOSE: To compare the diagnostic performance of MRI-based T1 relaxometry with dynamic contrast-enhanced ultrasound (CEUS)-based liver microcirculation for evaluation of liver function. MATERIALS AND METHODS: 22 patients underwent Gd-EOB-DTPA-enhanced MRI with T1 relaxometry and previous or consecutive CEUS examinations. A transverse 3D VIBE sequence with an inline T1 calculation was acquired and the reduction rate of T1 relaxation time (rrT1) was evaluated. For CEUS measurements (1–6 MHz), a bolus injection of 1.4 ml sulfur hexafluoride microbubbles were administered and both cine loops and single images from arterial phase up to late phase were stored. Quantification of time to …peak (TTP), rise time (RT), Wash- In Area Under the Curve (WiAUC), mean transit time (mTTI), the wash- in rate (WiR) and Wash-in perfusion index (WIPI)) was performed using a novel quantification software (VueBoxTM ). To compare quantification parameters, patients were classified in patients representing a healthy population (rrT1 > 50%, n  = 8) and those representing patients with liver disease (rrT1 < 50%, n  = 14). RESULTS: Comparing perfusion parameters TTP, mTTI, and WiR were higher in patients without liver disease compared to patients with impaired liver function (p  = 0.10–0.21). RT, WiAUC and WIPI were significantly lower in patients with impaired liver function (RT, 14.8±1.5 s; WiAUC, 17288±6179 a.u., WIPI, 1243±423) compared to patients without liver disease (RT, 21.2±2.6 s, p  = 0.032; WiAUC, 71534±25600, p  = 0.034; WIPI, 4286±1748, p  = 0.04). In a simple linear regression model, none of the perfusion parameters correlated significantly with rrT1 (p  = 0.08–0.63). CONCLUSION: Within the framework of this study, CEUS-based perfusion parameters were not able to assess severity of liver disease, however, WiAUC, RT and WIPI were significant perfusion parameters to make a rough assessment of liver function. Show more

Keywords: Chronic liver disease, CEUS, microcirculation, liver function

DOI: 10.3233/CH-168112

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 435-446, 2016

Authors: Marcon, J. | Trottmann, M. | Rübenthaler, J. | D’Anastasi, M. | Stief, C.G. | Reiser, M.F. | Clevert, D.A.

Article Type: Research Article

Abstract: INTRODUCTION: Shear wave elastography (SWE) and its derivative Supersonic Shear Imaging (SSI) are newer techniques for the determination of tissue elasticity by measuring the velocity of generated shear waves (SWV), which correlates positively with tissue stiffness. The techniques are integrated into many modern ultrasound systems and have been examined in the evaluation of viscoelastic properties of different organ systems. Two-dimensional shear wave elastography (2D SWE) of the testes has been found to be a useful tool in recent studies which included the determination of standard values in healthy volunteers. Three-dimensional shear wave elastography (3D SWE) is the latest …development in elastography and is made possible by generation of a multiplanar three-dimensional map via volumetric acquisition with a special ultrasound transducer. This technique allows the assessment of tissue elasticity in a three-dimensional, fully accessible organ map. The aim of this preliminary study was to both evaluate the feasibility of 3D SWE and to compare 2D and 3D SWE standard values in the testes of healthy subjects. MATERIAL AND METHODS: We examined the testes of healthy male volunteers (n  = 32) with a mean age of 51.06±17.75 years (range 25–77 years) by B-mode ultrasound, 2D and 3D SWE techniques in September of 2016. Volunteers with a history of testicular pathologies were excluded. For all imaging procedures the SL15-4 linear transducer (bandwidth 4–15 MHz) as well as the SLV16-4 volumetric probe (bandwidth 4–16 MHz) of the Aixplorer® ultrasound device (SuperSonic Imagine, Aix-en-Provence, France) were used. Seven regions of interest (ROI, Q-Box® ) within the testes were evaluated for SWV using both procedures. SWV values were described in m/s. Results were statistically evaluated using univariateanalysis. RESULTS: Mean SWV values were 1.05 m/s for the 2D SWE and 1.12 m/s for the 3D SWE. Comparisons of local areas delivered no statistically significant differences (p  = 0.11 to p  = 0.66), except for the region in the central portion in the superior part of the coronal plane (p  = 0.03). Testicular volume was significanty higher by a mean of 1.72 ml when measured with 3D SWE (p  = 0.001). CONCLUSION: 3D SWE proved to be a feasible diagnostic tool in the assessment of testicular tissue, providing the examiner with a fully accessible three-dimensional map in a multiplanar or multislice view. With this technique a more precise testicular imaging – especially if combined with the display of tissue stiffness in SWE – is available and therefore could improve the diagnostic work-up of scrotal masses or the routine investigation of infertile men. Further studies for a better understanding in the context of various testicular pathologies will be required. Show more

Keywords: Elastography, testes, infertility

DOI: 10.3233/CH-168115

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 447-456, 2016

Authors: Rübenthaler, J. | Paprottka, K.J. | Marcon, J. | Reiser, M. | Clevert, D.A.

Article Type: Research Article

Abstract: Ultrasound is a common and established imaging method for the initial characterization of renal lesions. The widespread used Bosniak classification (I–IV) classifies renal lesions in five individual groups using contrast-enhanced computer tomography (CE-CT), magnetic resonance imaging (MRI) and/or contrast-enhanced ultrasound (CEUS) imaging criteria. For complex pathologies, CEUS/MRI image fusion is a novel imaging technique for the differentiation of benign and malignant renal lesions. Compared to CE-CT and MRI alone, ultrasound image fusion offers the additional possibility of being a real-time imaging technique that can be used together with other cross-sectional imaging techniques. This article describes the newest possibilities of …image fusion with CEUS and MRI in detection and characterization of unclear renal lesions. Show more

Keywords: Renal lesions, bosniak classification, contrast-enhanced ultrasound, image fusion

DOI: 10.3233/CH-168116

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 457-466, 2016

Authors: Rübenthaler, J. | Paprottka, K.J. | Hameister, E. | Hoffmann, K. | Joiko, N. | Reiser, M. | Clevert, D.A.

Article Type: Research Article

Abstract: PURPOSE: To evaluate the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and computed tomography (CT) in the diagnosis of malignancies after liver transplantation. MATERIALS AND METHODS: A total of 23 patients with suspicious liver masses after liver transplantation with initial imaging series between September 2006 and September 2015 were statistically analysed. CEUS and CT were compared in their diagnosis of malignancy with CT being the gold standard. Out of 23 patients 9 patients showed malignant masses in CT, which could also be detected in 7 out 9 of cases using CEUS. RESULTS: CEUS showed a …sensitivity of 77.8%, a specificity of 100.0%, a positive predictive value (PPV) of 100.0% and a negative predictive value (NPV) of 87,5% in comparison with CT being the gold standard. In 2 cases CT showed a malignancy, contrary to the CEUS examination that was reported as normal. CONCLUSION: CEUS seems to be an alternative option for the evaluation of malignant masses in liver transplant patients. CEUS shows a high specificity and PPV in the detection of malignant liver masses. Show more

Keywords: Contrast-enhanced ultrasound (CEUS), computed tomography (CT), liver transplantation, malignancy

DOI: 10.3233/CH-168117

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 467-473, 2016

Authors: Rübenthaler, J. | Paprottka, K.J. | Hameister, E. | Hoffmann, K. | Joiko, N. | Reiser, M. | Clevert, D.A.

Article Type: Research Article

Abstract: PURPOSE: To compare the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and computed tomography (CT) in the diagnosis of vascular complications after liver transplantation in the postoperative phase. MATERIALS AND METHODS: A total of 60 patients with elevated liver function tests after liver transplantation with initial imaging studies between July 2005 and November 2015 were retrospectively analysed. CEUS and CT were compared in their diagnosis of vascular complications and CT was considered as the gold standard. Out of 60 patients 28 patients showed vascular complications in CT, which could also be detected in 25 out 28 of …cases using CEUS. Diagnostic accuracy was tested by using the CT diagnosis as the gold standard. RESULTS: CEUS showed a sensitivity of 89.3%, a specificity of 100.0%, a positive predictive value (PPV) of 100.0% and a negative predictive value (NPV) of 91,4% compared to CT as the gold standard. In 3 cases CT showed a vascular complication, whereas the CEUS examination was reported as normal. CONCLUSION: CEUS is a fast, non-ionizing imaging modality for the initial exclusion of vascular complications after liver transplantation. CEUS shows a high specificity and PPV in the detection of vascular complications. In unclear cases CT still is considered as the gold standard. Show more

Keywords: CEUS, contrast-enhanced ultrasound, CT, liver transplantation, vascular complication

DOI: 10.3233/CH-168118

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 475-482, 2016

Authors: Pregler, B. | Beyer, L.P. | Wiesinger, I. | Nießen, C. | Jung, E.M. | Stroszczynski, C. | Wiggermann, P.

Article Type: Research Article

Abstract: PURPOSE: To assess the value of dynamic contrast enhanced ultrasound (CEUS) for the detection of residual tumor tissue day 1 after microwave ablation (MWA) of large hepatocellular carcinoma (HCC) compared to MRI. MATERIAL AND METHODS: 30 consecutive patients (5 females, 25 males, mean age 64 years, age range 54–73 years) with an untreated HCC lesion larger than or equal to 3 cm underwent percutaneous MWA between 03/2014 and 04/2016. 1 patient was excluded because of an artificial pacemaker. All remaining 29 patients underwent 3-T MRI with liver-specific contrast agent and CEUS 1 day after ablation to detect residual …tumor tissue. The 6-week follow-up including CEUS and MRI was defined as the reference standard. RESULTS: Complete ablation was achieved in 23 of 29 treated lesions (79%). The sensitivities and specificities for the detection of residual tumor tissue on day 1 were 100% and 83% for CEUS and 87% and 67% for MRI resp. without the differences being statistically significant. CONCLUSION: CEUS allows a reliable assessment of therapeutic success of percutaneous ablation of large HCC lesions one day after the ablation. Its ability to visualize reactive periablation perfusion changes in real-time might be of advantage in the depiction of residual tumor tissue when compared to MRI imaging alone. Show more

Keywords: Contrast-enhanced ultrasound (CEUS), microwave ablation (MWA), hepatocellular carcinoma (HCC), imaging findings

DOI: 10.3233/CH-168113

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 483-490, 2016

Authors: Gemeinhardt, Ole | Poch, Franz G.M. | Hiebl, Bernhard | Kunz-Zurbuchen, Urte | Corte, Giuliano M. | Thieme, Stefan F. | Vahldiek, Janis L. | Niehues, Stefan M. | Kreis, Martin E. | Klopfleisch, Robert | Lehmann, Kai S.

Article Type: Research Article

Abstract: BACKGROUND: Continuing research ex vivo and in vivo with animal models is performed to advance the oncological safety of radiofrequency ablation (RFA) of liver tumors. In these experiments, frequently imaging modalities (e.g. MRI or CT) or macro-morphological measurements are used to determine the full extent of the different ablation zones inside of RFA lesions. However, no systematic study has been performed so far, which verified the accuracy of the macro-morphological findings. Therefore, the present study aimed to correlate histological and gross pathological findings of bipolar radiofrequency ablation zones of porcine livers with regard to cell viability in …vivo . METHODS: Bipolar RFA was performed in the liver of anaesthetized female domestic pigs under CT-guidance using an internally cooled 20 mm RFA applicator. Afterwards RFA cross sections of the liver were made in a perpendicular orientation to the applicator. Ablation zones were initially documented by photography and thereafter prepared for histological analysis. Latter was based on HE-staining and NADH-diaphorase cell viability staining. Micro- and macro-morphological sections were digitally analyzed along the cross-section area for statistical correlation. RESULTS: Three different RF ablation zones could be differentiated. A central zone showing no cell viability (white zone) was surrounded by a red zone. The red zone could be divided into an inner zone of viable and non-viable cells (red zone 1), followed by a zone of edema with mostly viable cells (red zone 2). Micro- and macro-morphological data showed a strong correlation for the white zone (r  = 0.95, p  < 0.01), the red zone 1 (r  = 0.85, p  < 0.01), and the red zone 2 (r  = 0.89, p  < 0.01). CONCLUSION: White zone and red zone could clearly be distinguished in gross pathology and histology after bipolar RFA of porcine liver tissue in vivo . The red zone could be differentiated into an inner zone of viable and non-viable cells and an outer zone with high cell viability and intercellular edema. A strong correlation of micro- and macro-morphology could be shown for all three ablation zones. With this knowledge, gross pathological examination can be used as a reliable indicator of lethally damaged tissue in bipolar RFA of in vivo porcine liver. Show more

Keywords: Liver, animal model, radiofrequency ablation (RFA), bipolar, viability staining, NADH-diaphorase

DOI: 10.3233/CH-168123

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 491-499, 2016

Authors: Beyer, L.P. | Pregler, B. | Nießen, C. | Michalik, K. | Haimerl, M. | Stroszczynski, C. | Jung, E.M. | Wiggermann, P.

Article Type: Research Article

Abstract: PURPOSE: Irreversible electroporation (IRE) is a focal non-thermal ablation technique that can be used to treat prostate cancer (Pca). The objective was to document the evolution of the volume of the prostate gland and the ablation zone after IRE of Pca. MATERIAL AND METHODS: A retrospective analysis of the image findings of CEUS 1 day, 6 weeks, 3 months and 6 months after IRE of 25 patients was conducted. The prostate gland volumes and the size of the ablation zones were documented. Changes in volume and size over time were calculated. RESULTS: There was a …significant volume reduction of the prostate gland in the first 3 months after ablation. The mean percentage change after 6 weeks was 34.3% with another decrease of 35.0% after 3 months. Volume did not change between month 3 and 6. Size of ablation zone measured in short- and long-axis significantly diminished until 6 months after ablation. CONCLUSION: CEUS showed a significant involution of the prostate gland during the first 3 months and a significant decrease of the ablation zone during the first 6 months after IRE of prostate cancer. Show more

Keywords: Contrast-enhanced ultrasound (CEUS), irreversible electroporation (IRE), prostate cancer, imaging findings

DOI: 10.3233/CH-168125

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 3, pp. 501-506, 2016