Blood rheology after cardiac valve replacement with mechanical prostheses or bioprostheses

Koppensteiner, Renate; Moritz, Anton; Schlick, W; Fenzl, G.; Roedler, Suzanne; Ehringer, H; Wollner, E

doi:10.1016/0002-9149(91)90104-s

Cited by 27 publications

(12 citation statements)

References 22 publications

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“…When endothelial cells are stripped from their biological substrates by high fluid stresses, the exposure of the extra cellular matrix proteins lining the surfaces can lead to the subsequent adherence, activation, and aggregation of platelets. 20,21 It is important to recognize that elucidating the hemodynamics of heart valves via sophisticated fluid dynamics testing is far from trivial. Prosthetic valves are geometrically very complex and the shape and motion of their leaflets are not known a priori, but rather evolve dynamically in response to the instantaneous flow conditions.…”

Section: The Link Between Hemodynamics and Clinical Complicationsmentioning

confidence: 99%

Flow in Prosthetic Heart Valves: State-of-the-Art and Future Directions

2005

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Since the first successful implantation of a prosthetic heart valve four decades ago, over 50 different designs have been developed including both mechanical and bioprosthetic valves. Today, the most widely implanted design is the mechanical bileaflet, with over 170,000 implants worldwide each year. Several different mechanical valves are currently available and many of them have good bulk forward flow hemodynamics, with lower transvalvular pressure drops, larger effective orifice areas, and fewer regions of forward flow stasis than their earlier-generation counterparts such as the ball-and-cage and tilting-disc valves. However, mechanical valve implants suffer from complications resulting from thrombus deposition and patients implanted with these valves need to be under long-term anti-coagulant therapy. In general, blood thinners are not needed with bioprosthetic implants, but tissue valves suffer from structural failure with, an average life-time of 10-12 years, before replacement is needed. Flow-induced stresses on the formed elements in blood have been implicated in thrombus initiation within the mechanical valve prostheses. Regions of stress concentration on the leaflets during the complex motion of the leaflets have been implicated with structural failure of the leaflets with bioprosthetic valves. In vivo and in vitro experimental studies have yielded valuable information on the relationship between hemodynamic stresses and the problems associated with the implants. More recently, Computational Fluid Dynamics (CFD) has emerged as a promising tool, which, alongside experimentation, can yield insights of unprecedented detail into the hemodynamics of prosthetic heart valves. For CFD to realize its full potential, however, it must rely on numerical techniques that can handle the enormous geometrical complexities of prosthetic devices with spatial and temporal resolution sufficiently high to accurately capture all hemodynamically relevant scales of motion. Such algorithms do not exist today and their development should be a major research priority. For CFD to further gain the confidence of valve designers and medical practitioners it must also undergo comprehensive validation with experimental data. Such validation requires the use of high-resolution flow measuring tools and techniques and the integration of experimental studies with CFD modeling.

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Section: The Link Between Hemodynamics and Clinical Complicationsmentioning

confidence: 99%

Flow in Prosthetic Heart Valves: State-of-the-Art and Future Directions

2005

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“…Transprosthetic blood flow and subsequent shear stresses not only damage red cells but also activate platelets. 25 Therefore, asides from the presence of PVR, post-TAVI subclinical hemolysis could represent a surrogate marker for a heightened risk of valve thrombosis and thromboembolic events.…”

Section: Discussionmentioning

confidence: 99%

Incidence and Risk Factors of Hemolysis After Transcatheter Aortic Valve Implantation With a Balloon-Expandable Valve

Laflamme

Puri

Ureña

et al. 2015

The American Journal of Cardiology

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“…These parameters (EA, fibrinogen, PV) are significantly correlated in the Pearson test. In many metabolic diseases as diabetes mellitus, arterial occlusive disease, or impairment of renal function, or in patients after cardiac valve replacement, elevation of red cell aggregation has been demonstrated as an unspecific but important disease activity parameter with eminent impact on microcirculation [7]. In addition at least one, hitherto unclassified protein favoring lymphedema might also lead to red cell aggregation.…”

Section: Discussionmentioning

confidence: 99%

“…Plasma viscosity analysis was performed with a viscometer of the capillary type at 25°C (Coulter-Harkness viscometer, ethylene diaminetetraacetic acid plasma) [5]. Red cell aggregation was determined using the MAI-Aggregometer, a photometric rheoscope (Myrenne, Roetgen, Germany) [6,7]. The measurements were obtained from heparinized blood (10 U/ml) adjusted to a standard hematocrit of 45% with autologous plasma at a low shear rate of 3/s.…”

Section: Rheologic Parametersmentioning

confidence: 99%

Impaired hemorheology in patients with postmastectomy lymphedema

Djavanmard

Michl

Korpan³

et al. 1996

Breast Cancer Res Tr

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Lymphedema of the arm is one of the most disabling and serious complications of breast cancer. Apart from tumor infiltration or fibrosis of lymphatic pathways, little is known about factors favoring the development of lymphedema. In the present study, we investigated the impact of rheologic parameters, e.g. red cell aggregation (EA) and plasma viscosity (PV), and of capillary morphology and capillary flow in patients with breast cancer with (n = 18) and without (n = 18) lymphedema. Patients with lymphedema showed a significant increase of red cell aggregation (p < 0.001) that indicates a systemic component of lymphedema and might offer a possibility of prevention and therapy of this condition. A hitherto unclassified protein factor favoring red cell aggregation and lymphedema might be postulated.

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Blood rheology after cardiac valve replacement with mechanical prostheses or bioprostheses

Cited by 27 publications

References 22 publications

Flow in Prosthetic Heart Valves: State-of-the-Art and Future Directions

Flow in Prosthetic Heart Valves: State-of-the-Art and Future Directions

Incidence and Risk Factors of Hemolysis After Transcatheter Aortic Valve Implantation With a Balloon-Expandable Valve

Impaired hemorheology in patients with postmastectomy lymphedema

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