• aortic valve repla
  • The procedures were divided into groups: aortic valve replacement (n = 163), mitral valve replacement (n = 60) and aortic-mitral (double) valve replacement (n = 33). (kuleuven.be)
  • Background In patients being considered for aortic valve replacement, there remains controversy over which design or tissue offers the best performance. (bmj.com)
  • Several therapeutic options are open to patients once the indication for aortic valve replacement has been confirmed. (wikipedia.org)
  • Aortic valve replacement using a homograft was first performed over 50 years ago on 24 July 1962 by Donald Ross at Guy`s Hospital, London and has been assessed in prospective randomized studies, e.g. in comparison to the Ross procedure. (wikipedia.org)
  • Aortic valve replacement using conventional cryopreserved homografts is currently performed only in about 3% of all patients, mostly to treat acute aortic valve endocarditis.1 Severe calcification of conventional homografts frequently occurs and is the main reason for its restrictive use, however, current guidelines confirm homografts as a valid alternative for young patients requiring anatomical reconstruction of the outflow tract. (wikipedia.org)
  • Decellularised aortic homografts (DAH) for aortic valve replacement and decellularised pulmonary valves (DPH) for pulmonary valve replacement have been developed by several groups and companies over the last decade. (wikipedia.org)
  • The likelihood of infection of the repaired aortic valve is much lower compared to what is seen after aortic valve replacement. (wikipedia.org)
  • As for aortic valve replacement the heart-lung machine is usually connected to the patient via aorta and right atrium. (wikipedia.org)
  • atrial
  • TTR (Time in Therapeutic Range) on warfarin has been shown to affect the risk of complications in atrial fibrillation, but has not been studied in patients with mechanical heart valves. (lu.se)
  • First the atrial skirt is deployed and the valve is positioned so the flat portion of the D-shaped frame is adjacent to the LVOT. (wikipedia.org)
  • Other causes are heart conditions including myocardial infarction, mitral valve disease, chronic atrial fibrillation, cardiomyopathies, and prosthesis, in all of which thrombi are prone to develop. (wikipedia.org)
  • prosthetic valves
  • Her other significant contributions include development of the stented aortic homograft (a graft of same-species tissue, in this case human tissue) for mitral valve replacement, surgical treatment of chronic thromboembolic disease, and pioneering techniques for the use of tissue cultures to discourage the formation of clots when prosthetic valves and circulatory assist devices are in use. (wikipedia.org)
  • stent
  • When the heart valve prosthesis is as implanted into the heart, the threads of the sewing ring and of the stent support ring interlock, and there are no plastic or metal surfaces, uncovered by biocompatible fabric, to be exposed to blood flow. (google.com)
  • bioprostheses
  • Heart valves derived from transgenic pigs can be valuable for the preparation of tissue-engineered bioprostheses, because of their biomechanical properties, stability, reduced immune response, making them safer for clinical applications. (springer.com)
  • Jamieson WR, von Lipinski O, Miyagishima RT, Burr LH, Janusz MT, Ling H, Fradet GJ, Chan F, Germann E. Performance of bioprostheses and mechanical prostheses assessed by composites of valve-related complications to 15 years after mitral valve replacement. (springer.com)
  • The stress performances of the stentless bioprostheses were similar to the mildly stenosed native aortic valve, whereas the performances of the stented and mechanical prostheses resembled that of native valves with mild-to-moderate stenoses. (bmj.com)
  • Conclusions Stentless bioprostheses displayed haemodynamics superior to stented or mechanical prostheses and had the closest performance to a normal, native aortic valve. (bmj.com)
  • leaflet
  • After attemping to design a bi-leaflet artificial heart valve, Dr. Albert Starr (born 1926) and engineer M. Lowell Edwards (1898-1982) abandoned the idea of trying to replicate a natural looking valve. (si.edu)
  • A heart valve prosthesis includes an annular body that has a fluid passageway and at least one rigid leaflet that is pivotally mounted in the passageway of the body. (google.com)
  • The heart valve prosthesis has a biasing mechanism that is connected to the body and leaflet and is configured to exert a force on the leaflet to move the leaflet to the closed position before a second fluid pressure exerted on an outflow surface of the leaflet exceeds a first fluid pressure exerted on an inflow surface of the leaflet. (google.com)
  • One popular design for a mechanical heart valve prosthesis includes an annular valve body in which a pair of opposed leaflet occluders are pivotally mounted. (google.com)
  • Once the mitral valve is accessed, repair procedures include annuloplasty and, more recently, suturing of the free edge of the anterior leaflet to the free edge of the back leaflet where the mitral insufficiency occurs. (google.com)
  • Each of the leaflets is adapted to flex inwardly into and out of engagement with another leaflet so as to close and open the valve in response to force by blood pressure. (google.com)
  • pulmonary
  • The acellular aortic and pulmonary valve conduits from transgenic pigs were used to estimate the biomechanical properties of the valve. (springer.com)
  • The energy required to break the native pulmonary valve derived from transgenic pigs was higher (20,475 ± 7,600 J m −2 ) compared with native non-transgenic pigs (12,140 ± 5,370 J m −2 ). (springer.com)
  • After acellularization, the energy to break the valves decreased to 14,600 and 8,800 J m −2 for the transgenic pulmonary valve and non-transgenic valve, respectively. (springer.com)
  • The pulmonary valves derived from transgenic pigs demonstrate better biomechanical properties compared with non-transgenic. (springer.com)
  • Their main purpose is to maintain unimpeded forward flow through the heart and from the heart into the major blood vessels connected to the heart, the pulmonary artery and the aorta. (wikipedia.org)
  • A further avenue open to patients is a so-called Ross operation, an extensive surgical procedure in which the diseased aortic valve is replaced by the patient`s pulmonary valve (autograft). (wikipedia.org)
  • The pulmonary valve then needs to be replaced by a heart valve prosthesis. (wikipedia.org)
  • Durability
  • However, in particular for young patients, it has been found that xenogenic valves do not provide satisfactory durability and rapid valve degeneration can occur within months. (wikipedia.org)
  • The ultimate goal of the procedure is the restoration of a normal form of the aortic valve, which will then lead to near-normal function and good durability of the repair. (wikipedia.org)
  • Minimally invasive procedures limit the possibility to precisely judge the form of the aortic valve and will thus lead to a higher uncertainty regarding function and durability of aortic valve repair. (wikipedia.org)
  • blood
  • These blood clots are referred to as thrombosis if they adhere to the heart valve. (google.com)
  • If the clots float away from the valve where they can occlude blood flow to another part of the body, the clots are referred to as thromboembolism. (google.com)
  • In a preferred embodiment, the prosthesis is formed of a base having a blood passageway and dual leaflets pivotally secured to the base to regulate the flow of blood through the passageway. (google.com)
  • Normally, these valves open to let blood flow through or out of your heart, and then shut to keep it from flowing backward. (icdlist.com)
  • In a condition known as mitral insufficiency, the mitral valve does not completely shut, and does not prevent the back-flow of blood to the left atrium from the left ventricle. (google.com)
  • The patient is then placed under extra-corporal blood circulation while the heart is stopped, and the heart chambers are opened to gain access to the mitral valve, usually through the left atrium. (google.com)
  • Natural heart valves are evolved to forms that perform the functional requirement of inducing unidirectional blood flow through the valve structure from one chamber of the heart to another. (wikipedia.org)
  • citation needed] However, current mechanical heart valves all require lifelong treatment with anticoagulants (blood thinners), e.g. warfarin, which requires monthly blood tests to monitor. (wikipedia.org)
  • Tissue heart valves, in contrast, do not require the use of anticoagulant drugs due to the improved blood flow dynamics resulting in less red cell damage and hence less clot formation. (wikipedia.org)
  • When blood pressure in the chamber of the heart exceeds that of the pressure on the outside of the chamber the ball is pushed against the cage and allows blood to flow. (wikipedia.org)
  • Caged ball valves have a high tendency to form blood clots, so the patient must have a high degree of anti-coagulation, usually with a target INR of 2.5-3.5. (wikipedia.org)
  • The metal ring holds, by means of two metal supports, a disc which opens and closes as the heart pumps blood through the valve. (wikipedia.org)
  • These blood thinners hold an inherent risk for severe bleeding episodes, which affects both professional and leisure activities and the majority of patients opt for mechanical valves for this reason. (wikipedia.org)
  • The clinic established by Amosov, produced about 7000 lung resections, more than 95000 operations for heart diseases, including about 36,000 operations with extra-corporeal blood circulation. (wikipedia.org)
  • Each year, the institute fulfilled about 3000 heart operations, including over 1500 - with extra-corporeal blood circulation. (wikipedia.org)
  • Because blood clots do not easily form on it, it is often advisable to line a blood-contacting prosthesis with this material in order to reduce the risk of thrombosis. (wikipedia.org)
  • She joined the NIH National Heart Institute (now the National Heart, Lung, and Blood Institute) in nearby Bethesda, Maryland, in 1958 under the mentorship of Dr. Andrew G. Morrow. (wikipedia.org)
  • It occurs when the heart muscle, or myocardium, receives insufficient blood flow. (wikipedia.org)
  • Anemia vasoconstricts the periphery so that red blood cells can work internally on vital organs such as the heart, brain, etc., thus causing lack of oxygen to the periphery. (wikipedia.org)
  • suture
  • 6 . The heart valve of claim 4 additionally comprising suture reinforcements. (google.com)
  • They are made of a metal ring covered by an ePTFE fabric, into which the suture threads are stitched in order to hold the valve in place. (wikipedia.org)
  • Failure
  • Either process burdens the heart and may lead to serious problems including heart failure. (wikipedia.org)
  • 50mm and risk factors and connective tissue disease The goal of the operation is the improvement of life expectancy and treatment of heart failure as the consequence of dysfunction of the aortic valve. (wikipedia.org)
  • surgical
  • This Institute was the first to conduct surgical treatment of heart diseases in the Ukrainian SSR (since 1955), the Institute began to conduct operations with extracorporeal circulation (1958), and mitral valve replacements (1963). (wikipedia.org)
  • His work on the surgical treatment of heart diseases won a State Prize of Ukraine (1988) gold medals (1967, 1982) and Silver Medal (1978) of the Exhibition of Economic Achievements of the USSR. (wikipedia.org)
  • Braunwald completed her training in general surgery at Georgetown University Hospital in Washington, D.C., with a postdoctoral fellowship in the surgical laboratory of Dr. Charles A. Hufnagel, inventor of the first artificial heart valve. (wikipedia.org)
  • Braunwald designed and fabricated experimental artificial mitral valve prostheses, implanting them in dogs at the National Heart Institute's surgical clinic in 1959. (wikipedia.org)