Relevant bibliographies by topics / Venous valve

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Venous valve'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Venous valve"

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Caggiati, Alberto, and Lorenza Caggiati. "Surgery of venous valve." Reviews in Vascular Medicine 1, no. 1 (March 2013): 15–23. http://dx.doi.org/10.1016/j.rvm.2013.02.002.

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Kistner, R. "Deep venous valve reconstruction." Cardiovascular Surgery 3, no. 2 (April 1995): 129–40. http://dx.doi.org/10.1016/0967-2109(95)90885-9.

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Kim, Hyoung-Ho, Kyung-Wuk Kim, Young Ho Choi, Chang Je Lee, and Sang Won Sun. "Flow Analysis in Damaged Venous Valves Installed with an Artificial Venous Valve." Transactions of the Korean Society of Mechanical Engineers - B 45, no. 6 (June 30, 2021): 333–40. http://dx.doi.org/10.3795/ksme-b.2021.45.6.333.

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Rosales, A. "Valve reconstructions." Phlebology: The Journal of Venous Disease 30, no. 1_suppl (February 28, 2015): 50–58. http://dx.doi.org/10.1177/0268355515569435.

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The history of venous valve reconstruction extends back to 1968 when Robert L Kistner performed the first internal valve plasty to treat deep venous axial reflux. Throughout the past 50 years other techniques of reconstructive deep venous surgery (RDVS) were developed, not only to repair but also to replace venous valves. And the fact that several surgeons and centers have undertaken RDVS in the treatment of chronic venous insufficiency (CVI) reporting outcomes, has added knowledge to define more clearly the role of this kind of specialized surgery. Patients who may benefit from RDVS are among those where conventional treatment with compression stockings combined with superficial surgery has failed. Ulcer-healing rates of up to 70% have been reported after RDVS and ulcer-free periods of up to 36 months have been generated. But during five-year follow-up, freedom from ulceration period and clinical improvement rates were reduced significantly. This raises then the issue and challenge of durability of RDVS since the average age of patients who can benefit from it is about 50 years.
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Weber, Benedikt, Jérôme Robert, Agnieszka Ksiazek, Yves Wyss, Laura Frese, Jaroslav Slamecka, Debora Kehl, et al. "Living-Engineered Valves for Transcatheter Venous Valve Repair." Tissue Engineering Part C: Methods 20, no. 6 (June 2014): 451–63. http://dx.doi.org/10.1089/ten.tec.2013.0187.

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BESSHO, Yoshiharu, Yingzhe WANG, Kaoru UESUGI, and Keisuke MORISHIMA. "A micro check valve structure imitating venous valves." Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2019 (2019): 2P1—G04. http://dx.doi.org/10.1299/jsmermd.2019.2p1-g04.

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Abel, KeithP. "VENOUS DISTENSION AND VALVE COMPETENCE." Lancet 327, no. 8484 (April 1986): 805. http://dx.doi.org/10.1016/s0140-6736(86)91817-9.

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Takase, Shinya, Luigi Pascarella, John J. Bergan, and Geert W. Schmid-Schönbein. "Hypertension-induced venous valve remodeling." Journal of Vascular Surgery 39, no. 6 (June 2004): 1329–34. http://dx.doi.org/10.1016/j.jvs.2004.02.044.

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Wilson, N. M., D. L. Rutt, and N. L. Browse. "In situ venous valve construction." British Journal of Surgery 78, no. 5 (May 1991): 595–600. http://dx.doi.org/10.1002/bjs.1800780525.

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Dalsing, Michael C. "In situ venous valve construction." Journal of Vascular Surgery 17, no. 3 (March 1993): 632–33. http://dx.doi.org/10.1016/0741-5214(93)90361-o.

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Dissertations / Theses on the topic "Venous valve"

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Midha, Prem Anand. "Long-term patency of a polymer vein valve." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29721.

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Thesis (M. S.)--Bioengineering, Georgia Institute of Technology, 2010.
Committee Chair: Ku, David; Committee Member: Gleason, Rudolph; Committee Member: Milner, Ross. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Tanner, Daniel Edward. "Design, analysis, testing, and evaluation of a prosthetic venous valve." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/51758.

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Chronic Venous Insufficiency (CVI) is characterized by chronic venous hypertension from blood pooling in the lower limbs. The resulting symptoms include leg pain, varicose veins, fatigue, venous edema, skin pigmentation, inflammation, induration, and ulceration. Reflux from incompetent venous valves is a factor in up to 94% of individuals with CVI. Current treatments of CVI include compression stockings, drug therapy, vein disabling, venous stenting, and surgical correction with varying rates of success. However, a minimally invasive correction of deep venous reflux does not currently exist. A transcatheter prosthetic venous valve has the potential to be an effective, minimally invasive treatment for deep venous reflux which could treat up to 1.4 million individuals in the United States suffering from venous ulceration and make more than 1.7 billion dollars each year. Previously developed prosthetic venous valves have had problems with competency, patency, thrombogenicity, biocompatibility, and incorrect sizing. To meet the clinical need a prosthetic valve needs to be developed which succeeds where previous valves have failed. This thesis describes the design, analysis, pre-clinical testing, and evaluation of a novel prosthetic venous valve. Design specifications for an effective prosthetic venous valve were created. Verification tests were developed and performed which demonstrated that the valve met every design specification. Finite element and computational fluid dynamics simulations were performed to analyze the valve and calculated a maximum shear rate of 2300 s-1 in the valve during the high forward flow after a Valsalva maneuver. The valve is made of a biocompatible material that has low thrombogenicity, Poly(vinyl-alcohol) cryogel. On the average, the valve allows less than 0.5 mL/min of reflux at low and high retrograde pressures even after 500,000 cycles, indicating that it will reduce the reflux of individuals with venous reflux by more than 99.4%. The valve closes in less than 0.07 seconds and allows the distal pressure to rise to an average of 7% of the equilibrium pressure 30 seconds after a simulated ankle flexion. The valve increases the outflow resistance an average of 2.3 mmHg*min/L which is much less than obstruction levels,≥ 5 mmHg*min/L. The valve can fit in a 16 French catheter and is capable of percutaneous delivery. The base of the valve is 1.5 times the diameter of the vein in which it is to be implanted to help correct orientation upon deployment. Fluid behind the valve’s leaflets is ejected with a forward flow rate of 400 mL/min, suggesting that thrombus formation will not occur at this location. A stented valve remained patent in a porcine blood flow loop for 3 hours. The valve remains competent without buckling in a constricted vein at rest. The valve can expand to fit a vein with a maximum diameter 1.4 times the valve's initial diameter with low risk of tearing or leaflet prolapse. An IACUC protocol for a 12 week study to test the valve in sheep was prepared and approved. A study to evaluate the valve in humans is proposed with endpoints that can be tested for statistical significance and compared with other treatments for CVI. A set of valves which will correct reflux in the majority of common femoral, femoral, and popliteal deep veins is proposed and a sizing guide for surgeons is provided. The minimum distance between prosthetic valves placed in the same vein segment is 13 cm. A comparison of this valve with previously developed prosthetic venous valves and recommendations for work to be performed in the future are given. The valve proposed in this work is the only valve to meet all design specification for an effective prosthetic venous valve, and therefore shows great potential to be a minimally invasive treatment for deep venous reflux.
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Farrell, Laura-Lee Amelia Catherine. "Prosthetic Vein Valve: Delivery and In Vitro Evaluation." Thesis, Available online, Georgia Institute of Technology, 2007, 2007. http://etd.gatech.edu/theses/available/etd-04042007-180135/.

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Sathe, Rahul D. "Design and Development of a Novel Implantable Prosthetic Vein Valve." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14495.

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Over seven million Americans suffer from Chronic Venous Insufficiency (CVI), a painful and debilitating disease that affects the superficial and deep veins of the legs. Problems associated with CVI include varicose veins, bleeding, ulcerations, severe swelling, deep vein thrombosis, and pulmonary embolism, which may lead to death. The presence of CVI results from damaged (incompetent) one-way vein valves in leg veins. These valves normally allow forward flow of blood to the heart, and prevent blood from pooling at the feet. However, incompetent valves allow reflux of blood, causing clinical problems. There are few effective clinical therapies for treating CVI. Vein valve transplantation is a surgical option for treatment. However, it is often difficult to find suitable donor valves. Very few prosthetic valves developed in the past have demonstrated sufficient clinical or mechanical functionality. Persistent problems include thrombus formation, leaking valves, and valves that do not open at physiologic pressure gradient. The primary objective of this research was to develop a clinically relevant functional prosthetic vein valve. The novel prosthetic valve is flexible, biocompatible, has low thrombogenecity, and is easy to manufacture. It was designed to address well-defined consumer needs and functional design requirements. The valve was required to 1) withstand 300 mmHg of backpressure with leakage less than 1.0 mL/min, 2) open with a pressure gradient less than 5 mmHg, and 3) meet criteria 1 and 2 after 500,000 cycles of operation. The valve met these design requirements in bench testing. The valve can open with a pressure gradient of 2.6 0.7 mmHg, and can withstand 300 mmHg with leakage less than 0.5 mL/min. The valve remained functional after opening and closing over 500,000 times. The valve presented in this research is operationally functional, and is a potential solution for treating venous incompetence in CVI patients.
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Anim, Kwaku. "Design, Development, Testing, and Evaluation of a Prosthetic Venous Valve." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1269252194.

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Raja, Vidya. "Computational Fluid Dynamics Analysis of a Prototypic, Prosthetic Venous Valve." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1186686575.

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Munger, Stephanie J., Xin Geng, R. Sathish Srinivasan, Marlys H. Witte, David L. Paul, and Alexander M. Simon. "Segregated Foxc2, NFATc1 and Connexin expression at normal developing venous valves, and Connexin-specific differences in the valve phenotypes of Cx37, Cx43, and Cx47 knockout mice." ACADEMIC PRESS INC ELSEVIER SCIENCE, 2016. http://hdl.handle.net/10150/621343.

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Venous valves (VVs) are critical for unidirectional blood flow from superficial and deep veins towards the heart. Congenital valve aplasia or agenesis may, in some cases, be a direct cause of vascular disease, motivating an understanding of the molecular mechanisms underlying the development and maintenance of VVs. Three gap junction proteins (Connexins), Cx37, Cx43, and Cx47, are specifically expressed at VVs in a highly polarized fashion. VVs are absent from adult mice lacking Cx37; however it is not known if Cx37 is required for the initial formation of valves. In addition, the requirement of Cx43 and Cx47 for VV development has not been studied. Here, we provide a detailed description of Cx37, Cx43, and Cx47 expression during mouse vein development and show by gene knockout that each Cx is necessary for normal valve development. The valve phenotypes in the knockout lines exhibit Cx-specific differences, however, including whether peripheral or central VVs are affected by gene inactivation. In addition, we show that a Cx47 null mutation impairs peripheral VV development but does not affect lymphatic valve formation, a finding of significance for understanding how some CX47 mutations cause inherited lymphedema in humans. Finally, we demonstrate a striking segregation of Foxc2 and NFATc1 transcription factor expression between the downstream and upstream faces, respectively, of developing VV leaflets and show that this segregation is closely associated with the highly polarized expression of Cx37, Cx43, and Cx47. The partition of Foxc2 and NFATc1 expression at VV leaflets makes it unlikely that these factors directly cooperate during the leaflet elongation stage of VV development. (C) 2016 Elsevier Inc. All rights reserved.
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Grimes, Randall Young. "A theoretical and experimental analysis of mitral regurgitation and its interactions with pulmonary venous inflow." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/17246.

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Goudot, Guillaume. "Applications innovantes des ultrasons en pathologie vasculaire : utilisation de l'imagerie ultrarapide dans l'analyse de la rigidité artérielle et des ultrasons pulsés en thérapie Arterial stiffening assessed by ultrafast ultrasound imaging gives new insight into arterial phenotype of vascular Ehlers–Danlos mouse models Aortic wall elastic properties in case of bicuspid aortic valve Segmental aortic stiffness in bicuspid aortic valve patients compared to first-degree relatives Wall shear stress measurement by ultrafast vector flow imaging for atherosclerotic carotid stenosis Pulsed cavitational therapy using high-frequency ultrasound for the treatment of deep vein thrombosis in an in vitro model of human blood clot." Thesis, Sorbonne Paris Cité, 2018. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=2215&f=13951.

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Phillips, Mark N., and n/a. "Anatomy of microvenous valves of normal and venous ulcerated lower limbs." University of Otago. Dunedin School of Medicine, 2005. http://adt.otago.ac.nz./public/adt-NZDU20060523.142055.

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Venous disease is a very common disease that affects millions of people worldwide. While some of the factors that cause the development of varicose veins are well understood, the aetiology of venous ulceration is poorly understood. It has been demonstrated that venous valve failure in the large veins is an important factor leading to the development of varicose veins, however whether similar valves exist in the very small superficial veins of the human leg, and what role these valves may have in venous disease, is unknown. Therefore, the purpose of this study is to: 1. Identify whether venous valves are present in the very small superficial veins of the human leg, and if they are present, 2. Describe the density, size distribution, morphology, and regional distribution of these microvenous valves in �normal� cadaveric legs 3. Compare the �normal� microvenous valves from cadaveric tissue with microvenous valves from pathologic legs with chronic venous disease, to answer the hypothesis that individuals that develop venous ulceration have fewer microvenous valves than the normal population. In order to examine microvenous valves, two main methods have been utilised, E12 sheet plastination and vascular casting. These methods in combination provide valuable insights into the anatomy of microvenous channels, and allow examination and quantification of the venous valves. Using several techniques, this study has shown that microvenous valves are present within the very small veins of the superficial tissue of the human leg. These microvalves have been shown to be most prevalent in the smallest of the veins, down to 18[mu]m in diameter. Approximately 60% of the valves were found to be associated with tributaries. The gaiter region was demonstrated to contain the lowest number and density of microvenous valves, significantly less that the upper or mid calf regions. In addition, the gaiter region was found to have a much lower proportion of microvalves in the most superficial veins, when compared with the other regions examined. Contrary to our hypothesis, the number and density of microvalves in venous diseased legs was not different to that of normal legs. Similarly, the size and regional distributions were also not different. However, the microvalves from the venous diseased legs were significantly stretched and incompetent, allowing retrograde flow from the large veins through to the dermal capillaries. In conclusion, this study has shown that venous valves are present in the smallest of the superficial veins of the human leg, and that their density and distribution is not different between normal and venous diseased individuals. However, the microvalves from the diseased legs were incompetent and allowed retrograde flow. The role that these valves play in normal and pathological circulation is unclear, and warrants further examination.
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Books on the topic "Venous valve"

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Gottlob, Rainer, and Robert May. Venous Valves. Vienna: Springer Vienna, 1986. http://dx.doi.org/10.1007/978-3-7091-8827-9.

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Robert, May, and Geleff S, eds. Venous valves: Morphology, function, radiology, surgery. Wien: Springer-Verlag, 1986.

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Brasil, Francisco de Paula de Souza. O ICM e os impostos sobre vendas no Brasil. Rio de Janeiro: Forense, 1987.

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Gardner, A. M. N. The return of blood to the heart: Venous pumps in health and disease. London: J. Libbey, 1989.

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Gardner, A. M. N. The return of blood to the heart: Venous pumps in health and disease. 2nd ed. London: Libbey, 1993.

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Gardner, A. M. N. The return of blood to the heart: Venous pumps in health and disease. London: Libbey, 1989.

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Pikkujämsä, Mikko. Oikeusperiaatteet ja arvonlisäverotus kiinteistöalalla. Helsinki: Kauppakaari, 2001.

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Dendy, Mervyn. The VAT treatment of 'imported services': The zero-rating under the Value-Added Tax Act 89 of 1991 of services performed outside South Africa by foreign non-vendors. Cape Town, South Africa: SiberInk, 2012.

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Goy, David. Vat and property. London: Sweet & Maxwell, 1989.

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I͡Albulganov, A. A. Postateĭnyĭ kommentariĭ k Zakonu Rossiĭskoĭ Federat͡sii "O plate za zemli͡u". Moskva: Spark, 2003.

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Book chapters on the topic "Venous valve"

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Phifer, Travis J. "The Venous Valve." In Textbook of Angiology, 1101–11. New York, NY: Springer New York, 2000. http://dx.doi.org/10.1007/978-1-4612-1190-7_87.

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Kistner, Robert L. "Venous valve surgery." In Vascular Surgery, 538–51. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4899-6854-8_54.

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Maleti, Oscar, and Marzia Lugli. "Valve Reconstruction for Deep Venous Reflux." In Current Management of Venous Diseases, 217–29. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65226-9_17.

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Yeo, Khung Keong, and Jason Rogers. "Venous Access Management." In Atlas of Percutaneous Edge-to-Edge Mitral Valve Repair, 131–45. London: Springer London, 2012. http://dx.doi.org/10.1007/978-1-4471-4294-2_8.

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Vaidyanathan, Subramoniam. "Deep Vein Valve Reconstruction." In Chronic Venous Disorders of the Lower Limbs, 183–93. New Delhi: Springer India, 2014. http://dx.doi.org/10.1007/978-81-322-1991-0_18.

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Ohashi, Tsuyoshi, Hao Liu, and Takami Yamaguchi. "Computational Fluid Dynamic Simulation of the Flow through Venous Valve." In Clinical Application of Computational Mechanics to the Cardiovascular System, 186–89. Tokyo: Springer Japan, 2000. http://dx.doi.org/10.1007/978-4-431-67921-9_18.

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Freedom, R. M., and L. N. Benson. "Anomalies of Systemic Venous Connections, Persistence of the Right Venous Valve and Silent Cardiovascular Causes of Cyanosis." In Neonatal Heart Disease, 485–95. London: Springer London, 1992. http://dx.doi.org/10.1007/978-1-4471-1814-5_29.

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bt Aziz, Nur Shazilah, Nabilah bt Ibrahim, Kamil Abdullah, and Noor Hafizzatul Izzah bt Mat Harun. "Computational Fluid Dynamics Simulation on Blood Velocity and Vorticity of Venous Valve Behaviour." In 9th International Conference on Robotic, Vision, Signal Processing and Power Applications, 617–25. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-1721-6_67.

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Gottlob, Rainer, and Robert May. "History." In Venous Valves, 1–10. Vienna: Springer Vienna, 1986. http://dx.doi.org/10.1007/978-3-7091-8827-9_1.

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Gottlob, Rainer, and Robert May. "Venous Valves in Arterialized Veins." In Venous Valves, 177–81. Vienna: Springer Vienna, 1986. http://dx.doi.org/10.1007/978-3-7091-8827-9_10.

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Conference papers on the topic "Venous valve"

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Packer, Ryan, Brian D. Jensen, and Anton E. Bowden. "Design and Modeling of a Prosthetic Venous Valve." In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-86164.

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Chronic Venous Insufficiency (CVI) is a disease of the lower limbs that affects millions of people in the United States. CVI results from incompetent venous valves. The purpose of venous valves is to prevent retrograde blood flow to the lower limbs. Valve failure can lead to edema, pain, and ulcers. One solution that has great potential is to create an implantable venous valve that could restore function of the venous system. No prosthetic venous valves are clinically used currently because of problems with biocompatiblility and thrombogenicity caused by high shear rates. This paper presents a prosthetic venous valve that could overcome these difficulties by using carbon-infiltrated carbon nanotubes (CI-CNTs). This material has been proven to be thrombo-resistant, biocompatible due to its non-reactive properties, and durable. The valve was designed to be initially open and to close with physiological pressures. Finite element modeling showed that, with a hydrostatic pressure of 20 mmHg (the minimum hydrostatic pressure in the common femoral vein), it fully closed with a maximum stress of 117 MPa, which is below the ultimate strength of CI-CNTs. A computational fluid dynamics analysis demonstrated the valve would cause a maximum shear rate of 225.1 s−1, which is less than the maximum shear rate in the body. Hence, this valve would be less likely than previous prosthetic valves to develop blood clots. Currently, this is the lowest shear rate reported for a prosthetic venous valve. These results demonstrate that a CI-CNT prosthetic venous valve has the potential to be an effective treatment for CVI.
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"PRECLINICAL TESTING OF A NEW VENOUS VALVE." In International Conference on Biomedical Electronics and Devices. SciTePress - Science and and Technology Publications, 2008. http://dx.doi.org/10.5220/0001050000300035.

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Varadan, Vijay K., and Vasundara V. Varadan. "Micropump and venous valve by micro stereo lithography." In SPIE's 7th Annual International Symposium on Smart Structures and Materials, edited by Vijay K. Varadan. SPIE, 2000. http://dx.doi.org/10.1117/12.388901.

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Lowe, O. DG. "RHEOLOGY AND VENOUS THROMBOEMBOLISM." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643990.

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Changes in the composition of the blood, venous stasis, and interaction of the blood with the vessel wall (Virchow's triad) all have rheological aspects which may promote venous thrombogenesis.Blood composition and rheology. Increasing levels of venous haematocrit and fibrinogen increase bulk blood viscosity, especially at low shear rates such as are encountered in veins, when red cell aggregation occurs. Static blood requires a minimum shear stress for flow (yield stress), which is also strongly dependent on haematocrit and fibrinogen levels. Increases in haematocrit and fibrinogen also promote platelet adhesion and aggregation. Polycythaemia carries an increased risk of venous thromboembolism, which can be reduced by lowering the haematocrit; conversely, anaemic patients (renal failure, pernicious anaemia) have a subnormal prevalence of pulmonary embolism at autopsy. Increased preoperative levels of haematocrit, fibrinogen and blood viscosity predicted postoperative deep vein thrombosis in some studies, but not in others: they have complex relationships to other risk factors and illnesses. Postoperative changes in haematocrit, fibrinogen and blood viscosity may also be relevant to thrombogenesis, as may haemoconcentration in leg veins.Venous flow disturbance and rheology. The flow behaviour of particles and cells in venous valve pockets has been studied by Karino: particles and cells were observed to leave mainstream flow and circulate in paired vortices in low-shear areas within the valve pockets. A cell-poor hypoxic area at the apex of the valve pocket may favour thrombogenesis. Valve pockets might therefore act as in vivo aggregometers, with optimal conditions for activated cells or coagulation products to promote platelet and red cell aggregation, which might be facilitated by increases in haematocrit or fibrinogen. Sevitt has observed cellular aggregates in valve pockets at autopsy, which might act as a nidus for thrombus initiation. Successive layers of thrombus will disturb flow steamlines, as well as generating procoagulant activity: hence a series of "aggregometers" might result in successive bursts of thrombosis and the layered structure of venous thrombi observed by Sevitt. Variations in haematocrit, fibrinogen and red cell aggregation may influence stasis of blood following venous occlusion by thrombus, and hence affect thrombotic extension; they may also influence residual lung perfusion following pulmonary embolism.Therapeutic aspects of rheology. Leg stockings and other physical methods of preventing deep vein thrombosis may improve flow disturbance in valve pockets, as well as in axial veins. The efficacy of perioperative dextran in prevention of venous thromboembolism may partly reflect haemodilution and its rheological consequences. Likewise, postoperative defibrination with ancrod reduced the incidence and extent of deep vein thrombosis after hip surgery, which may partly reflect reductions in plasma viscosity and red cell aggregation. Defibrination with ancrod reduced the haemodynamic disturbance, and the mortality, of experimental pulmonary embolism in dogs, possibly by increasing residual perfusion.. Similarly, improved perfusion after thrombolytic therapy of pulmonary embolism in man may reflect the rheological consequences of fibrinogen depletion, as well as thrombolysis.
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Farrell, Laura-Lee, Deepak Nair, Ross Milner, and David Ku. "Thrombotic Potential of a Prosthetic Vein Valve." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-175925.

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Over seven million Americans suffer from chronic venous insufficiency, secondary to valvular dysfunction, with few effective clinical therapies. Chronic Venous Insufficiency (CVI) is a painful and debilitating disease that affects the superficial and deep veins of the legs. After deep venous thrombosis, the vein valves leaflets become adherent, fold over, or are absorbed into the vein wall. Incompetent valves allow reflux and subsequent pooling of blood in the legs. The resultant CVI causes severe leg edema, skin breakdown, and possible gangrene. Current clinical therapies are only modestly effective and include vein stripping and ligation, valvuloplasty, vein valve transposition, and vein valve transplantation. Valvuloplasty is the most definitive of CVI treatment, though this surgical treatment is rarely performed due to its difficulty. The quest for a better solution continues.
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Van Der Smissen, Benjamin, Koen Van Canneyt, Mathias Vermeulen, Martin Bayley, Andrew V. Narracott, Rado Kaminsky, Peter Van Ransbeeck, Pascal R. Verdonck, and Patrick Segers. "Innovative Design of a Venous Valve Intended for PIV Measurements." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53515.

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Today, hemodialysis is a common therapy to treat people with severe chronic kidney disease. This therapy strongly relies upon the vascular access that connects the patient’s circulation to the artificial kidney and which is obtained by surgically creating an arteriovenous fistula in the arm. However, due to the high flows involved at the venous side and elevated venous pressures, the functioning of venous valves in the arm is significantly disturbed, which too often bring about serious dysfunctions or complications in the patient [1–2]. To this end, research is done to improve the outcome of vascular access in patients on hemodialysis therapy by means of computational modeling [3]. One crucial challenge, however, is experimental validation of these computer models, preferably by using Particle Image Velocimetry (PIV) for simulations of flow fields. Yet, the task of modeling the venous valve is daunting because this valve functions at very low physiological pressure differences. Moreover, PIV requires an experimental model to be fully transparent. In this study, we propose an innovative design of a PIV-compatible venous valve model which has the ability to function at minimal pressure differences and which is able to generate valuable PIV data.
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Muhd Suberi, Anis Azwani, Wan Nurshazwani Wan Zakaria, Razali Tomari, and Nabilah Ibrahim. "Quantitative ultrasound venous valve movement: early diagnosis of deep vein thrombosis." In First International Workshop on Pattern Recognition, edited by Xudong Jiang, Guojian Chen, Genci Capi, and Chiharu Ishll. SPIE, 2016. http://dx.doi.org/10.1117/12.2242815.

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Wijeratne, N. S., and K. A. Hoo. "Numerical studies on the hemodynamics in the human vein and venous valve." In 2008 American Control Conference (ACC '08). IEEE, 2008. http://dx.doi.org/10.1109/acc.2008.4586482.

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Hull, Russell D., and Gary E. Raskob. "TREATMENT OF DEEP VENOUS THROMBOSIS AND ECONOMIC ASPECTS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642968.

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Initial therapy with intravenous heparin, followed by long-term anticoagulant therapy for three months or more, is the treatment of choice for most patients with acute venous thrombosis. Inferior vena caval interruption, using a transvenously inserted filter, is the management of choice for preventing pulmonary embolism in patients in whom anticoagulant therapy is contraindicated, and in the very rare patient in whom anticoagulant therapy is ineffective. The role of thrombolytic therapy has not been completely resolved. It was hoped that thrombolytic therapy would minimize or prevent the post-phlebitic syndrome; unfortunately, this may not be the case because the critical factor in the development of the post-phlebitic syndrome appears to be venous valve damage, which occurs early in the formation of venous thrombosis. Thrombolytic therapy should be considered in selected patients with acute massive venous thrombosis (eg. the patient with phlegmasia cerulea dolens).Intravenous heparin administered in doses which prolong the activated partial thromboplastin time (APTT) to 1.5 to 2 times control is highly effective and is associated with a low frequency (2%) of recurrent venous thromboembolism. A recent randomized trial (1) in patients with proximal-vein thrombosis indicates that failure to achieve an adequate anticoagulant response (APTT > 1.5 times control) is associated with a high risk (20%) of recurrent venous thromboembolism. Therefore, sufficient heparin should be administered to maintain the APTT above 1.5 times the control value.Intravenous heparin is continued for 7 to 10 days, overlapped with oral anticoagulant therapy for 4 to 5 days before heparin is stopped. Multiple randomized clinical trials in patients with proximal-vein thrombosis indicate that when heparin is administered for 7 to 10 days, followed by adequate long-term anticoagulant therapy, the frequency of recurrent venous thromboembolism is very low (2%). An alternative approach is to commence heparin and oral anticoagulants together at the time of diagnosis, and to discontinue heparin on the fourth or fifth day. If this latter approach is effective, it would avoid 4 to 5 days of unnecessary hospitalization in many patients, and would markedly reduce the cost of initial heparin therapy. A recent randomized trial (2) in patients with submassive venous thromboembolism suggests that 4 to 5 days of initial heparin therapy is effective and safe, but this approach must be evaluated by further randomized clinical trials before it is routinely recommended.Recent clinical trials indicate that inadequate long-term therapy in patients with proximal-vein thrombosis results in a high frequency (40-50%) of recurrent venous thromboembolism and is cost-ineffective because of the diagnostic and treatment costs of recurrent venous thromboembolism (3). The risk of recurrence is markedly reduced to 2% by adequate long-term anticoagulant therapy with warfarin sodium or adjusted subcutaneous heparin; both of these approaches are markedly more cost-effective than inadequate long-term therapy (3). Oral anticoagulant therapy with warfarin sodium for three months (or longer in selected patients), is less expensive than adjusted subcutaneous heparin and is preferred in most patients with acute proximal-vein thrombosis. The risk of bleeding associated with oral anticoagulant therapy can be reduced to less than 5%, without loss of effectiveness for preventing recurrent venous thromboembolism, by adjusting the dose of warfarin sodium to achieve a less intense anticoagulant effect (PT 1.25 to 1.5 times control using a rabbit brain thromboplastin such as Simplastin or Dade-C, corresponding to an INR of 2.0 to 3.0). Less intense warfarin sodium therapy is the most cost-effective of the alternative long-term anticoagulant regimens (3). Adjusted dose subcutaneous heparin is an effective and safe alternative to warfarin sodium; although slightly more expensive, it is the long-term regimen of choice in pregnant patients, and in patients returning to geographically remote areas lacking the facilities for anticoagulant monitoring (in whom the dose is adjusted during the first few days of long-term therapy and then fixed). REFERENCES: (1) Hull R, Raskob G, Hirsh J et al. N Engl J Med 1986;315:1109-1114. (2) Gallus A, Jackaman J, Tillett J et al.Lancet 1986;2:1293-1296. (3) Hull R, Raskob G, Hirsh J, Sackett DL. JAMA 1984;252:235-239.
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McNally, Andrew, A. George Akingba, and Philippe Sucosky. "Computational Hemodynamic Assessment of a Novel Modular Anastomotic Valve Device for Improving Hemodialysis Vascular Access Patency." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14560.

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End-stage renal disease (ESRD) occurs as a result of any renal injury that chronically decreases renal excretory and regulatory function. ESRD patients are most commonly treated with hemodialysis (HD) to manage their renal failure while awaiting kidney transplant. Current practices for maintenance of HD vascular access consist of arteriovenous fistulas (AVFs) or grafts (AVGs), which are both fraught with problems that compromise the patency and use of these surgically created shunts. The major cause of shunt failure is thrombosis caused by occlusion of the outflow venous anastomosis and draining vein. Intimal hyperplasia (IH), which consists of the thickening of the innermost layer of the vessel wall, is the initial pathological event leading to shunt stenosis/thrombosis and has been associated with the presence of flow disturbances and abnormal wall shear stress (WSS) at the graft-vein anastomosis. Therefore, the improvement of HD via the enhancement of vascular access patency requires the development of a novel vascular access technology preserving the normal hemodynamics of the native vein.
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Reports on the topic "Venous valve"

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Moskovitz, D., C. Harrington, W. Shirley, R. Cowart, R. Sedano, and F. Weston. State Electricity Regulatory Policy and Distributed Resources: Distributed Resource Distribution Credit Pilot Programs--Revealing the Value to Consumers and Vendors. Office of Scientific and Technical Information (OSTI), October 2002. http://dx.doi.org/10.2172/15001122.

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