Clinical Hemorheology and Microcirculation - Volume 71, issue 2

Authors: Heine-Geldern, A. | Broer, P.N. | Prantl, L. | Brebant, V. | Anker, A.M. | Kehrer, A. | Thiha, A. | Lonic, D. | Ehrl, D. | Ninkovic, M. | Heidekrueger, P.I.

Article Type: Research Article

Abstract: BACKGROUND: While complication rates in free tissue transfers have continuously decreased over time due to improved techniques, the intraoperative use of vasopressors and their negative effects on flap microcirculation and patency of the anastomoses remains controversial. To further elucidate this matter, this retrospective study examines the effect of intraoperative vasopressors on free gracilis muscle and free fasciocutaneous anterolateral thigh (ALT) flaps for lower extremity reconstruction. METHODS: A total of 425 patients underwent 437 free flaps for lower limb reconstruction. The series was divided into two groups: use of intraoperative vasopressors (V, n  = 318) or no use (NV, n … = 119). The data were retrospectively screened for patients’ demographics, perioperative details, and surgical complications. RESULTS: The two groups were comparable regarding patient comorbidities. Independently of flap type, there were no significant difference between the groups regarding major complications, i.e. total flap loss (V: 5.35% versus NV: 5.04%, p  = 0.899) or revision rate (V: 18.87% versus NV: 12.61%; p  = 0.122), or minor complications, i.e. partial flap loss (V: 6.29% versus NV: 5.88%, p  = 0.875). CONCLUSION: This study confirms that the usage of intraoperative vasopressors has no influence on free flap survival rate in lower extremity reconstruction. It seems to be no difference between free muscle or fasciocutaneous flaps. Show more

Keywords: Vasopressors, microsurgery, free flaps, norepinephrine, lower extremity reconstruction

DOI: 10.3233/CH-189411

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 2, pp. 193-201, 2019

Authors: Horobin, Jarod T. | Watanabe, Nobuo | Hakozaki, Masaya | Sabapathy, Surendran | Simmonds, Michael J.

Article Type: Research Article

Abstract: BACKGROUND: Red blood cells (RBC) are exposed to varying shear stress while traversing the circulatory system; this shear initiates RBC-derived nitric oxide (NO) production. OBJECTIVE: The current study investigated the effect of varying shear stress dose on RBC-derived NO production. METHODS: Separated RBC were prepared with the molecular probe, diamino-fluoreoscein diacetate, for fluorometric detection of NO. Prepared RBC were exposed to discrete magnitudes of shear stress (1–100 Pa), and intracellular and extracellular fluorescence was quantified via fluorescence microscopy at baseline (0 min) and discrete time-points (1–30 min). RESULTS: Intracellular RBC-derived NO fluorescence was significantly increased (p  < 0.05) …following shear stress exposure when compared to baseline at: i) 1 min–100 Pa; ii) 5 min–1, 5 Pa; iii) 15 min–1, 5, 35 Pa; iv) 30 min–35 Pa. Extracellular RBC-derived NO fluorescence was significantly increased (p  < 0.05) following shear stress exposure when compared to baseline at: i) 5 min – 100 Pa; ii) 15 min–100 Pa; iii) 30 min–40, 100 Pa. CONCLUSIONS: These data indicate that: i) a dose-response exists for the RBC-derived production of NO via shear stress; and ii) exposure to supra-physiological shear stress allows for the leakage of RBC intracellular contents (e.g., RBC-derived NO). Show more

Keywords: Haemorheology, erythrocyte, mechanotransduction, vasodilation, biocompatibility

DOI: 10.3233/CH-189412

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 2, pp. 203-214, 2019

Authors: Ahmadizad, Sajad | Daraei, Ali | Bassami, Minoo | Rahmani, Hiwa

Article Type: Research Article

Abstract: BACKGROUND: L-Arginine, the precursor of NO might be involved in improving the cardiovascular disorders via regulation of functional properties of erythrocytes. OBJECTIVE: This study investigated the effects of L-Arginine supplementation on responses of red blood cell (RBC) properties to high intensity interval exercise (HIIE). METHODS: Ten overweight healthy men participated voluntarily in the study and performed two HIIE trials with and without L-Arginine in two separate weeks. The HIIE protocol included 12 intervals of 3-min encompassed 1-min running at 100% of vVO2 max and 2-min active recovery at 40% of vVO2 max. Three blood samples …were taken before and after supplementation, and immediately after exercise; and were used to measure red blood cell properties. RESULTS: The HIIE protocol increased hematocrit, hemoglobin and lactate significantly (P  < 0.05), but had no significant effect on RBC aggregation, RBC deformability, and fibrinogen concentration. When data were compared for two trials no significant differences between the responses of RBC properties to two HIIE protocols were detected (P  > 0.05), whereas the increases in lactate concentration following HIIE was significantly lower in L-Arginine than placebo trial (P  < 0.05). CONCLUSIONS: It is concluded that L-Arginine consumption prior to HIIE does not lead to any improvement in RBC properties during HIIE in overweight healthy men. Show more

Keywords: Intermittent exercise, nitric oxide, hemorheology, erythrocyte, blood flow

DOI: 10.3233/CH-189413

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 2, pp. 215-223, 2019

Authors: Varga, Gabor | Ghanem, Souleiman | Szabo, Balazs | Nagy, Kitti | Pal, Noemi | Tanczos, Bence | Somogyi, Viktoria | Barath, Barbara | Deak, Adam | Peto, Katalin | Nemeth, Norbert

Article Type: Research Article

Abstract: BACKGROUND: Pathomechanism and optimal renoprotective protocol for remote ischemic preconditioning (RIPC) have not been completely revealed yet. OBJECTIVE: To investigate micro-rheological effects of early and delayed RIPC in renal ischemia-reperfusion (I/R) in the rat. METHODS: In Control group the left femoral artery was cannulated and the left kidney was gently exposed. In the I/R group 45-minute renal ischemia with 120-minute reperfusion period was monitored. In the RIPC groups a 3×10-minute protocol was applied using tourniquet around the right hind-limb 1 hour (RIPC-1) or 24 hours (RIPC-24) prior to the I/R. Blood samples were taken for …testing blood gas, acid-base, metabolic and hemorheological parameters. RESULTS: Lactate and potassium concentration significantly increased in I/R that could be reduced by RIPC, especially in RIPC-24. Creatinine concentration increased further in RIPC groups. I/R and RIPC-1 decreased the pH, RIPC-24 increased. RIPC-24 reduced the drop in base excess. Erythrocyte deformability worsened by renal I/R. In RIPC groups deformability decreased additively. However, RIPC-1 could improve the condition. RIPC-24 showed the highest erythrocyte aggregation values during reperfusion. CONCLUSIONS: Renal I/R worsened metabolic and micro-rheological parameters that could be modulated by RIPC protocols. However, it could not be decided whether the early or the delayed protocol is better. Show more

Keywords: Ischemia-reperfusion, remote ischemic preconditioning, kidney, red blood cell deformability, red blood cell aggregation

DOI: 10.3233/CH-189414

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 2, pp. 225-236, 2019

Authors: Georgieva, M. | Prantl, L. | Utpatel, K. | Wiesinger, I. | Stroszczynski, C. | Jung, F. | Jung, E.M.

Article Type: Research Article

Abstract: OBJECTIVE: Objective of the study was to assess the performance of ultrasound strain elastography combined with conventional B-mode ultrasound to diagnose suspicious breast lesions (BI-RADS 4 and 5). METHODS: Between January 2015 and December 2017, a total of 86 patients (55±17.9 years) with solid or unclear, non-cystic breast lesions were enrolled in the study. The breast lesions were evaluated by B-mode ultrasound and subsequent ultrasound strain elastography. Ultrasound features including echo pattern, lesion shape, marginal characteristics, calcifications, orientation and posterior features are useful for differentiating benign breast lesions from malignant ones. Malignant ultrasound features are irregular shape, hypoechoic …pattern, spiculated margin, nonparallel orientation and posterior shadowing. Lesions with benign features such a circumscribed margin were classified as low conspicuous. In patients with highly conspicuous malignant masses ultrasound-guided core needle biopsy or surgical excision was performed. RESULTS: Among the 86 patients, 60 masses were histologically proven and 36 of these were malignant. Of the malignant lesions 26 invasive carcinomas were of no special type (NST), 1 invasive lobular carcinoma, 3 ductal carcinomas in situ and 6 metastases. 20 of these patients had breast density classified as ACR 3 or 4. The mean size of the masses was 1.2 cm (range: 0.5–5 cm). Based on ultrasound B-mode imaging, the lesions were classified as BI-RADS category 4 (n  = 20; three 4a, nine 4b and eight 4c) and BI-RADS category 5 (n  = 16). One patient had to be reclassified after strain elastographxy to BI-RADS 3. The sensitivity of ultrasound with strain elastography and additional B-Mode ultrasound for the characterization of solid breast lesions was 97%, for conventional B-mode alone 92%; the respective specificities were 82% and 73%, respectively. CONCLUSION: Ultrasound elastography can be a supplementary approach to conventional ultrasound to improve the diagnostic accuracy of malignant breast lesions. Show more

Keywords: Breast lesions, ultrasound, elastography, breast imaging reporting and data system, invasive carcinoma of no special type (NST)

DOI: 10.3233/CH-189415

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 2, pp. 237-247, 2019

Authors: Lee, Hoyoon | Na, Wonwhi | Lee, Byoung-Kwon | Lim, Chae-Seung | Shin, Sehyun

Article Type: Research Article

Abstract: The analysis of platelet aggregation and thrombosis kinetics has significantly advanced with progress in microfluidic technology. However, the results of platelet aggregation tests do not fully reflect the observed clinical outcomes. To address the present unmet clinical needs, the basic but essential biology of platelets should be reconsidered in relation to the characteristics of microfluidic systems employed for platelet tests. To this end, the present article provides an overview of commercially available point of care devices and focuses on recent microfluidic studies, describing their measurement principles. We critically discuss the characteristics of the microfluidics systems used to evaluate the complex …processes underlying platelet aggregation, and that are specifically designed to mimic the pathophysiological environment of blood vessels, including hemodynamic factors as well as blood vessel injury. To this end, we summarize unsolved issues related to the application of platelet function tests based on microfluidics. Overall, we confirm that platelet function tests based on microfluidics provide a versatile platform that encompasses a variety of basic research, as well as clinical diagnostic applications. Show more

Keywords: Platelets, function, test, microfluidic, diagnostic

DOI: 10.3233/CH-189416

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 2, pp. 249-266, 2019

Authors: Putz, Franz J. | Verloh, Niklas | Erlmeier, Anna | Schelker, Roland C. | Schreyer, Andreas G. | Hautmann, Matthias G. | Stroszczynski, Christian | Banas, Bernhard | Jung, Ernst M.

Article Type: Research Article

Abstract: AIM: To assess the influence of difficult examination conditions onto the diagnostic performance of CEUS (contrast-enhanced ultrasound) in focal liver lesions (FLL). METHODS: 77 liver CEUS examinations of 75 patients were analysed retrospectively. CEUS was performed as the first diagnostic procedure by one experienced sonographer after bolus injection of 1.0 up to 2.4 ml sulphur hexafluoride microbubbles using a high-end ultrasound device with a high resolution multifrequency probe (1–6 MHz). The combination of complementary imaging (CT or MRI), histology and CEUS follow up of at least 6 months was considered. Cross tables were used to define the sensitivity, specificity, positive …predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy. Chi-Square Test analysed categorical data. RESULTS: The patients were between 18 and 84 years old (mean 62±11 years). 26 patients suffered from liver cirrhosis (33.8%). 52 patients (67.5%) received therapy for an oncological disease. The final diagnosis showed 52 malignant FLLs including 24 hepatocellular carcinomas (HCCs), 9 cholangiocellular carcinomas (CCCs) and 19 metastases from different primary tumors. In the other 25 patients no malignant lesions could be detected, three of them presenting however liver haemangioma and two of them liver cysts. The overall lesions’ size according to the CEUS findings ranged from 7 to 100 mm (mean 31.1±22.6 mm). Under good examination conditions the malignant potential of a tumor was diagnosed correctly by CEUS in 98.0% of cases (Sensitivity 97.1%, Specificity 100%, PPV 100%, NPV 94.1%, diagnostic accuracy 98.0%). Limited examination conditions (e.g. obesity, meteorism) were present in 35.1% of cases with a decrease of the diagnostic accuracy to 92.6% (Sensitivity 100%, Specificity 77.8%, PPV 90.0%, NPV 100%). CONCLUSION: Despite the influence of difficult examination conditions, CEUS is – in the hands of an experienced sonographer – an excellent diagnostic procedure for the assessment of liver lesions. Show more

Keywords: CEUS, liver imaging, interdisciplinary ultrasound department, examination conditions, tumor

DOI: 10.3233/CH-189417

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 2, pp. 267-276, 2019

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

Article Type: Research Article

Abstract: Non-swelling hydrophobic poly(n -butyl acrylate) network (cPn BA) is a candidate material for synthetic vascular grafts owing to its low toxicity and tailorable mechanical properties. Mesenchymal stem cells (MSCs) are an attractive cell type for accelerating endothelialization because of their superior anti-thrombosis and immune modulatory function. Further, they can differentiate into smooth muscle cells or endothelial-like cells and secret pro-angiogenic factors such as vascular endothelial growth factor (VEGF). MSCs are sensitive to the substrate mechanical properties, with the alteration of their major cellular behavior and functions as a response to substrate elasticity. Here, we cultured human adipose-derived mesenchymal stem cells …(hADSCs) on cPn BAs with different mechanical properties (cPn BA250, Young’s modulus (E ) = 250 kPa; cPn BA1100, E  = 1100 kPa) matching the elasticity of native arteries, and investigated their cellular response to the materials including cell attachment, proliferation, viability, apoptosis, senescence and secretion. The cPn BA allowed high cell attachment and showed negligible cytotoxicity. F-actin assembly of hADSCs decreased on cPn BA films compared to classical tissue culture plate. The difference of cPn BA elasticity did not show dramatic effects on cell attachment, morphology, cytoskeleton assembly, apoptosis and senescence. Cells on cPn BA250, with lower proliferation rate, had significantly higher VEGF secretion activity. These results demonstrated that tuning polymer elasticity to regulate human stem cells might be a potential strategy for constructing stem cell-based artificial blood vessels. Show more

Keywords: Poly(n-butyl acrylate), mechanical property, vascular graft, mesenchymal stem cells, VEGF

DOI: 10.3233/CH-189418

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 2, pp. 277-289, 2019