Clinical Hemorheology and Microcirculation - Volume 52, issue 2-4

Authors: Schoen, Kornelia | Hirschberg, Ruth M. | Plendl, Johanna | Kaessmeyer, Sabine

Article Type: Research Article

Abstract: Intense angiogenesis, vascular remodelling as well as regression of its vasculature are prerequisites for ovarian function with its cyclically developing and regressing follicles and corpora lutea. So far neither a stringent explanation for the enormous angiogenic potential of the ovary nor its cellular origins have been suggested. In an earlier study of our work group, endothelial cells were isolated from the bovine corpus luteum and cultivated in vitro. They performed vasulogenesis in vitro and showed properties of progenitor cells. The present study aimed at in situ identification of endothelial progenitor cells (EPCs) in the bovine ovary. Immunohistochemical examinations, based on …the detection of KDR and CD34 co-labelled cells – a marker combination that amongst others is commonly accepted as typical for EPC identification – were performed. Hormonal cycle dependent expression varieties were analysed by the measurement of mRNA amounts of CD34 and KDR as well as the stem cell marker CD133 (Prominin-1). Ovarian samples comprising corpora lutea of varying stages (developing and mature corpus luteum, corpus luteum in regression, corpus luteum of pregnancy) from 17 adult cows were examined. Results show that specific mRNA of CD133, CD34 and KDR was expressed in ovaries of all luteal stages. Expression data analysis revealed significant differences in CD133 and CD34 expression levels between the luteal stages but no significant differences in KDR expression. CD34/KDR co-immunoreactive cells were predominantly situated within the media of arterial vessel wall. The detection of ovarian EPCs represents an important step towards further understanding of the mechanisms involved in the reproductive biology and pathophysiology of the ovary. Show more

Keywords: Adult endothelial progenitor cells, resident stem cells, adult vasculogenesis, Prominin-1, VEGF-R2, vessel wall, reproductive organ, hormonal cycle, qPCR, double immunohistochemistry

DOI: 10.3233/CH-2012-1585

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 67-84, 2012

Authors: Niehues, S.M. | Müller, C. | Plendl, J. | Richardson, K.C. | Gemeinhardt, O. | Hünigen, H. | Unger, J.K. | Jung, F. | Hamm, B. | Hiebl, B.

Article Type: Research Article

Abstract: Minipigs are frequently used for scientific research as they are easy to handle and the dimensions of their vascular system do not change after 20 months of age. Although surgical interventions under anaesthesia are often performed in the supine position the effects of this positioning on lung functionality in minipigs have not been systematically described. This study aimed to analyse the influence of supine positioning on the macrostructure of the lung and the pulmonary density by the use of computed tomography imaging in pre-adult Göttingen minipigs. Twelve pre-adult female minipigs were used in the study and lung density was investigated …in both the prone and the supine positions. The time between the scans in prone and supine positions was less than 5 minutes (296 ± 6 sec). In the prone position lung density did not differ between the dorsal and ventral part of the lung (−641 ± 72 Hounsfield units [HU]). However in the supine position there was a ventrodorsal gradient of decreasing density (ventral part of the lung: −497 ± 106 HU, dorsal part of the lung: −723 ± 51 HU). The changes in lung density were not accompanied by changes in lung volume (829 ± 191 ml). These results suggest an influence of the body position on the ventilation/perfusion ($\dot{V}_A/\!\dot{Q}$) matching of the lung which could possibly result in lowered lung oxygenation as well as in an increased heart activity in the supine position. Additionally, due to the steep course of the vena cava caudalis from the caval foramen in the diaphragm across to the heart (in contrast to the more shallow course in the prone position) the activity of the heart necessary to pump the venous blood to the right atrium has to be higher in the supine position than in the prone position. In pigs the capacity of the heart to increase frequency is limited due to a diastolic/systolic (D/S) ratio <1. Supine positioning may possibly increase their risk of cardiovascular complications. Show more

Keywords: Computed tomography, minipigs, lung density, positioning, perfusion

DOI: 10.3233/CH-2012-1586

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 85-92, 2012

Authors: Wege, A.K. | Schardt, K. | Schaefer, S. | Kroemer, A. | Brockhoff, G. | Jung, E.M.

Article Type: Research Article

Abstract: Purpose: In this study we investigated the sensitivity of high resolution ultrasound (HRU) in the detection of small liver tumors and its microcirculation in a humanized tumor mouse model (HTM). These mice develop a complete human immune system and human breast cancer growth in the liver which allows the investigation of antibody based immunotherapies under human like conditions. Method: HTM were generated by the co-transplantation of human breast cancer cells and human hematopoietic stem cells. HRU, Doppler sonography (CCDS), contrast enhanced ultrasound (CEUS) and color-coded elastography were performed on all HTM and confirmed by histopathological assessment. Results: Using HRU and …CEUS, noncystic solid liver lesions between 2 and 11 mm (mean 3.5 mm) size were detectable in HTM. Granulomatous areas were identified by B-scan imaging, showing areas of higher stiffness in elastography and areas without contrast media uptake in the late phase (CEUS). In addition, CEUS detected capillary microcirculation of benign and malignant liver lesions smaller than 10 mm. Conclusion: Beyond human breast cancer HTM additionally developed small parenchymal liver lesions, which could be characterized by HRU in combination with CEUS and elastography in-vivo. Nevertheless, the defined diagnoses of solid liver lesions less than 5 mm require confirmation by histopathology. Show more

Keywords: Humanized tumor mice (HTM), breast cancer, liver tumors, elastography, contrast-enhanced ultrasound (CEUS), microcirculation

DOI: 10.3233/CH-2012-1587

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 93-106, 2012

Authors: Paprottka, P.M. | Ingrisch, M. | Koelln, A. | Zengel, P. | Cyran, C.C. | Nikolaou, K. | Reiser, M.F. | Clevert, D.A.

Article Type: Research Article

Abstract: Purpose: To evaluate “bolus-tracking” (BT) and “flash-replenishment” (FR) for the assessment of tissue hemodynamics by contrast-enhanced ultrasound (CEUS) in an experimental small-animal-squamous-cell-carcinoma-model. Since the underlying tissue is the same, strong correlations between parameter outcomes of both techniques are expected. Methods and materials: Human hypopharynx-carcinoma-cells were subcutaneously injected into the left flank of 18 female athymic-nude-rats. After 10 days of subcutaneous tumour growth, bolus tracking and flash-replenishment measurements were performed consecutively in the same imaging plane in each rat after bolus-injection of SonoVue via the lateral tail vein using a high-end ultrasound system with a 15 MHz probe. Video-sequences were analysed …with dedicated software (VueBox® , Bracco-Suisse® ). From BT measurements, the parameters peak enhancement (PEBT ), wash-in area-under-the-curve (Wi-AUCBT ), mean transit time (MTTBT ), wash-in-rate (WiRBT ) and perfusion-index (Wi-PIBT ) were derived; FR yielded estimates of relative-blood-volume (rBVFR ), mean transit time MTTFR , relative blood flow rBFFR and wash-in rate Wi-RFR . Results: In all rats, BT and FR measurements could be completed successfully. Highly significant correlations were observed between rBVFR and PEBT , rBVFR and Wi-AUCBT , rBVFR and MTTBT , rBVFR and WiPIBT , MTTFR and MTTBT , rBFFR and PEBT , rBFFR and Wi-AUCBT , rBFFR and WiRBT , rBFFR and WiPIBT , WiRFR and PEBT , WiRFR and Wi-AUCBT , WiRFR and WiRBT and WiRFR and WiPIBT . Conclusion: Whereas bolus tracking can be used in a wide range of modalities including CEUS, CT and MR, FR as a technique for the assessment of tissue hemodynamics is unique to CEUS. Although BT and FR yield different parameters, the underlying tissue hemodynamics are equal. In this work, we were able to demonstrate strong correlations between different parameters of both modalities in a small-animal-tumor-model, indicating that flash-replenishment is a valid alternative to the more established bolus-tracking technique. Although the lack of absolute, quantitative parameters hinders a direct comparison of both modalities, FR and BT should both be suitable for a relative comparison, e.g. between baseline and follow-up examinations. Show more

Keywords: Bolus tracking, flash replenishment, contrast-enhanced ultrasound (CEUS), human squamous cell carcinoma, experimental animal model

DOI: 10.3233/CH-2012-1588

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 107-114, 2012

Authors: Matschke, K. | Knaut, M. | Kanig, R. | Mrowietz, C. | Hiebl, B. | Jung, F.

Article Type: Research Article

Abstract: During extracorporeal circulation (ECC) controlled hypothermia is a common method of myocardial protection due to a reduction of the myocardial oxygen consumption. Although the beneficial aspects of hypothermia on the myocardial metabolism have been widely demonstrated the effect of hypothermia on the myocardial oxygen tension (PmyO2 ) is unclear. For this reason the PmyO2 of German Landrace pigs (male, three months of age) during ECC was analysed under mild hypothermia (32°C, n = 6 pigs) and under normothermia (n = 10 pigs, control group) within a time period of 23 min (1400 sec). Flexible invasive Clark type microcatheters were …used to measure the PmyO2 in the beating heart. During normothermal ECC a continuous PmyO2 increase from 36.5 ± 15.8 mmHg to 52.6 ± 27.2 mmHg (+44.1%) after 1400 sec was measured (p = 0.02). In contrast, mild hypothermia caused a continuous PmyO2 decrease from initially 46.9 ± 17.5 mmHg to 36.7 ± 20.8 mmHg (−21.8%, p < 0.013) in the test period. Electrocardiography revealed no signs of ischemia or arrhythmia during normo- and hypothermic ECC. It seems obvious that mild hypothermia results in a reduction of the oxygen transfer to the myocardial cells and that this effect outweighs the beneficial effects of hypothermia in the myocardium which are related to reduced oxygen consumption. However, in mild hypothermia oxygen supply to the myocardium remained sufficient for normal myocardial function. Show more

Keywords: Hypothermia, pig, microcirculation, myocardial oxygen tension

DOI: 10.3233/CH-2012-1589

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 115-122, 2012

Authors: Wiggermann, P. | Heibl, M. | Niessen, C. | Müller-Wille, R. | Gössmann, H. | Uller, W. | Poschenrieder, F. | Schreyer, A.G. | Wohlgemuth, W.A. | Stroszczynski, C. | Jung, E.M.

Article Type: Research Article

Abstract: Purpose: To evaluate therapeutic efficacy of degradable starch microsphere (DSM)-TACE in hepatocellular carcinoma (HCC) using Dynamic Contrast-Enhanced Ultrasonography (DCE-US) based perfusion analysis. Materials and methods: A total of 60 DCE-US examinations were performed in 15 selected patients who underwent DSM-TACE with EmboCept® S for the treatment of advanced HCC. DCE-US was performed via i.v. application of ultrasound contrast media before and 24 hours post embolization. In addition DCE-US was performed with i.a. contrast application via the angiographic catheter right before and after the embolization. Microcirculation of embolized HCC lesions was quantified using a dedicated perfusion software by two experienced radiologists …in consensus. Results: Significant reduction of microvascularization (PE, WiAUC and WiR) was seen right after DSM-TACE and during 24 hour follow-up. Mean PE was 342.22 ± 97.80 prior to embolization, 59.28 ± 29.74 post embolization (p = 0.019) and 18.83 ± 7.03 during follow-up (p ≤ 0.01). Mean WiAUC was 1103.21 ± 432.05 prior to embolization 267.69 ± 151.80 post embolization (p = 0.023) and 105.10 ± 44.43 during 24 hour follow-up (p ≤ 0.01). The corresponding values for WiR were 224.91 ± 57.97 prior-, 38.14 ± 18.80 post embolization (p = 0.034) and 6.97 ± 2.68 during follow up (p ≤ 0.01). Conclusion: In this study, therapeutic efficacy of DSM-TACE in HCC using DCE-US based perfusion analysis could be demonstrated. Show more

Keywords: HCC, DSM-TACE, DCE-US

DOI: 10.3233/CH-2012-1590

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 123-129, 2012

Authors: Lehmann, Christian | Cerny, Vladimir | Abdo, Islam | Kern, Hartmut | Sander, Michael | on behalf of the Microcirculation Diagnostics and Applied Studies (MiDAS) Investigators

Article Type: Research Article

Abstract: Macrohemodynamic targets such as mean arterial pressure, cardiac output, and mixed or central venous oxygen saturation have been used to guide treatment of patients presenting circulatory shock. However, it has been shown that despite of improvement of macrocirculatory parameters there is persisting microcirculatory dysfunction. The restoration of microvascular perfusion in order to improve oxygenation, prevent tissue hypoxia, and maintain organ function represents the main aim of hemodynamic resuscitation. Therefore, microcirculatory targets may represent the most important endpoints to optimize therapy of circulatory shock.

DOI: 10.3233/CH-2012-1591

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 131-139, 2012

Authors: Mueller, Steffen | Meier, Johannes K. | Wendl, Christina M. | Jung, Ernst Michael | Prantl, Lukas | Gosau, Martin

Article Type: Research Article

Abstract: Purpose: Evaluation of two complementary methods, i.e. luminescence ratiometric oxygen imaging (LROI) and contrast-enhanced ultrasound (CEUS) for postoperative evaluation of the perfusion of osseocutaneous fibular free flaps used for mandibular reconstructions. Patients and methods: 15 patients with microvascular re-anastomosed osseocutaneous fibular flaps were included in this trial. Perfusion of the cutaneous part of the flap was determined by measuring a fluorescent oxygen sensor foil covering the flap's skin surface with a handheld fluorescence-microscope. The sensor contains a reservoir of oxygen that is consumed by the tissue, which corresponds to the perfusion status of a flap. Measurements were done before explantation, …after successful anastomosis and 1 day after surgery. Additionally, flap perfusion was qualitatively evaluated by contrast-enhanced ultrasound (CEUS) in 13 out of 15 patients. Ultrasound examinations were carried out with a high resolution linear probe after an intravenous bolus injection of 2.4 ml SonoVue® within the first 14 days after surgery. Results: Out of the 15 harvested and transplanted flaps, 3 showed microcirculatory problems on the first postoperative day. All complications were detected by LROI prior to clinical signs. For LROI, we were able to confirm the threshold slope value of 0.3 for differentiating between well perfused and compromised flaps as suggested in our previous study. CEUS showed qualitatively detectable bone perfusion in the 13 measured flaps. 2 flaps that were lost on the second and third postoperative day were also lost for CEUS control. The flap survival rate was 87%, and the complication rate was 33%. Conclusion: LROI has been proven to deliver reproducible objective results for monitoring cutaneous flaps. In addition, CEUS is a promising method for evaluating the microcirculation of the deeper parts (such as bone) of osseocutaneous flaps. Both methods supplement each other, thus allowing the monitoring of all levels of osseocutaneous flaps. Show more

Keywords: Osseocutaneous flap, fibular free flap, mandibular reconstruction, luminescence ratiometric oxygen imaging, contrast-enhanced ultrasound, tissue microcirculation

DOI: 10.3233/CH-2012-1592

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 141-151, 2012

Authors: Wendl, C.M. | Müller, S. | Meier, J. | Fellner, C. | Eiglsperger, J. | Gosau, M. | Prantl, L. | Stroszczynski, C. | Jung, E.M.

Article Type: Research Article

Abstract: The reliable detection of cervical lymph node (LN) metastases is the planning basis of a selective neck dissection for patients with oral squamous cell carcinoma (OSCC). The aim of this study was to evaluate whether contrast-enhanced ultrasound (CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) together are able to improve the preoperative characterisation of LNs. A time intensity curve analysis has been performed using CEUS and DCE-MRI for ten LNs, where one LN has been examined per patient. The studied LNs consist of five with and five without metastases. In CEUS the mean time to peak (TTP) was 18 s …(range 13–29 s, standard deviation (SD) ± 7 s) for benign and 12 s (range 9–16 s, SD ± 4 s) for malignant LNs. In DCE-MRI the mean TTP was 27 s (range 18–36 s, SD ± 9 s) for benign and 21 s (range 18–27 s, SD ± 5 s) for malignant LNs. Moreover, the relative signal change with respect to reference tissue was significantly higher for LNs with than for those without metastases in both CEUS and DCE-MRI. A combination of imaging morphology, CEUS and DCE-MRI might be a promising method for a reliable differentiation of benign and malignant LNs. Show more

Keywords: CEUS, dynamic contrast-enhanced MRI, lymph node metastases

DOI: 10.3233/CH-2012-1593

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 153-166, 2012

Authors: Jung, E.M. | Wiggermann, P. | Greis, C. | Eder, F. | Ehrich, J. | Jung, W. | Schreyer, A.G. | Stroszczynski, C. | Ganzer, R.

Article Type: Research Article

Abstract: Aim: Detection of prostate cancer lesions using transrectal contrast enhanced ultrasound (CEUS) of the prostate utilizing quantitative perfusion analysis. Method: 20 patients (mean age 63 years, 47–71) with biopsy proven prostate cancer underwent transrectal ultrasound (TRUS) prior to radical prostatectomy by 2 experienced examiners using a multifrequency endocavitary probe (5–9 MHZ, LOGIQ E9, GE Healthcare, Chalfont St Giles, UK) to detect cancer-suspect lesions. CEUS was performed dynamically up to 3 Min after bolus injections of 2.4 ml SonoVue® (BRACCO, Italy). Digital cine loops were analyzed by an independent blinded examiner using perfusion quantification software with colour-coded parametric images in …order to define suspect regions based on the perfusion-related parameters early wash in rate (WIR), mean transit time (MTT) and rise time (RT). The results of CEUS perfusion analysis were compared with the histopathology after surgery, obtained from whole mount sections. Results: After prostatectomy and histopathology, 34 prostate cancer foci were found in 20 patients. In 30/34 cases an early enhancement within the tumor was detected by CEUS perfusion analysis without early wash out. By evaluating the MTT and RT tumor detection was possible in 29/34 and 25/34 cases. The highest detection rate of prostate cancers was obtained by analysis of early contrast enhancement (priot to the normal prostate parenchyma), with a sensitivity of 88%, specificity 100%, NPP 60%, PPV 90%, in clinically suspicious cases with good correlation to the postoperative histopathological findings (r = 0.728). Conclusion: This pilot study demonstrates, that quantitaive analysis of perfusion parameters obtained with transrectal CEUS could be helpful for characterization of neoplastic microcirculation of prostate cancer, for preoperative localization of cancer-suspect areas and for therapy guidance and management. Show more

Keywords: Prostate cancer, CEUS, perfusion analysis, microcirculation, surgery

DOI: 10.3233/CH-2012-1594

Citation: Clinical Hemorheology and Microcirculation, vol. 52, no. 2-4, pp. 167-177, 2012