Addressing Issues with Thrombosis and Investigating Backflow in the Bileaflet
Mechanical Heart Valve (St. Jude Medical Valve)
Introduction
The past six decades have fostered the rise of remarkable innovations in the design and production of mechanical heart valves that are safe and hemodynamically favorable. The mechanical heart valves have been used widely over this time with the successful implantation of over 100,000 Omni-Brand tilting-disc valves and 300,000 Hall-Brand tilting-disc valves since the late 70's [1]. In 1977 the St. Jude bileaflet valves were introduced, and since then, over 1.3 million pyrolytic carbon valves have been implanted [1]. Patients with enervating disease of the natural heart valves can have either mechanical or tissue valve replacements. These include stenosis (hardening and calcification of the valves), insufficiency (due to thinning or tearing of the valves), valvular defects, and infections. The focus of this paper will be on the mechanical valve replacements.
History
Dr. Charles Hufnagel first implanted his design of the Hufnagel ball valve in 1952. The implant consisted of a ball chamber made of methacrylate containing a methacrylate ball [Fig 1]. This ball material was later replaced with nylon to construct a hollow nylon ball coated with silicon to diminish mechanical noise. Though a number of these valves were surgically implanted and yielded low wear, the significant disadvantage to this design was that it could only be inserted into the descending aorta to treat aortic insufficiencies [2]. Later in conjunction with Dr. Dwight Harken, Hufnagel worked on stabilizing the ball chamber as to deter negative impact on the aortic walls.
In the late 1950's, the idea of the Starr-Edw...
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Medtronic (Minneapolis) and Edwards Lifesciences (Irvine, California) are not strangers to patent lawsuits. Edwards is specializing in the production of artificial heart valves and new hemodynamic monitoring technology, whereas Medtronic is specializing in the production of medical devices. In the past, the two companies have had problems in patent infringement lawsuits over annuloplasty procedures and endovascular grafts (1,2). However, the latest patent infringement lawsuit has been filed and reported between Medtronic and Edwards Lifesciences. Edwards claimed that it has prior intellectual property rights in the new transcatheter aortic valve technology.
The bond between humans and nature, it is fascinating to see how us has humans and nature interact with each other and in this case the essay The Heart’s Fox by Josephine Johnson is an example of judging the unknown of one's actions. She talks about a fox that had it's life taken as well as many others with it, the respect for nature is something that is precious to most and should not be taken advantage of. Is harming animals or any part of nature always worth it? I see this text as a way of saying that we must be not so terminate the life around us. Today I see us a s experts at destroying most around us and it's sad to see how much we do it and how it's almost as if it's okay to do and sadly is see as it nature itself hurts humans unintentionally
Nishimura, R. A., & McGoon, M. D. (1999). Editorial: Perspectives on mitral-valve prolapse. The New England Journal of Medicine, 341(1), 48-50. Retrieved from http://search.proquest.com/docview/223939414?accountid=158514
One of the four defects that are specific to Tetralogy of Fallow is referred to as a Ventricular Septal Defect. According to the National Heart, Lung, and Blood Institute; this defect is characterized by a hole in the septum (Schumacher 2011). The ventricles are the main chambers in the heart that pump and the hole usually occurs along the wall separating the two lower chambers or ventricles of the heart. In a normal heart, the septum functions to prevent blood from merging between the left and right sides of the heart. If the defect is large it creates pulmonary congestion from the increase workload from the heart. Small defects are virtually asymptomatic and sound like a murmur upon auscultation. Many ventricular septal defects clos...
There are four different categories of treatment: lifestyle changes, surgical procedures, non-surgical procedures, and medications. Lifestyle changes include having a healthy diet; increasing physical activity; eliminating cigarettes, alcoholic beverages, and illicit drugs; and getting enough rest and sleep; losing excess weight. These lifestyle changes are to lower the patient’s blood pressure, cholesterol, and reducing any other future medical conditions. There are also surgical options to help cure, prevent, or control cardiomyopathy. Surgical method include a septal myectomy, surgically implanted devices, and a heart transplant. A septal myectomy is used to specifically treat hypertrophy cardiomyopathy which is where the heart muscle cells enlarge and cause the walls of the ventricles to thicken. The thickening of the walls may not affect the size of the ventricles but instead may affect the blood flow out of the ventricle. Usually along with the ventricles swelling, the septum in between the ventricles can become enlarged and block the blood flow causing a heart attack. When medication is not working well to treat hypertrophic cardiomyopathy, a surgeon will open the chest cavity and remove part of the septum that is blocking blood flow. Surgically implanted devices include a pacemaker, a cardiac resynchronization therapy device, a left ventricular assist device, and an implantable
The development of the artificial heart began in the early 1950’s. The initial prototype, developed in 1970’s by the artificial developmental staff at the University of Utah, allowed 50 hours of sustained life in a sheep. Although this was called a success, the implantation of the artificial heart left the sheep in a weakened state. It wasn’t until late 1970’s and the early 1980’s where the improvement of the artificial heart actually received attention as a possible alternative to a heart transplant. The remodeled product of the early 1970’s did more than just the 50 hours of sustained life; it enabled the cow to live longer and to live a relatively normal life, with the exception of a machine attached to the animal.
..., Welsh R, Feindel C, Lichtenstein S. Transcatheter aortic valve implantation: a Canadian Cardiovascular Society position statement. Can J Cardiol. 2012;28:520-8.
Many experiments later, a device was born. In the late 1960s a man by the name of Carpentier developed the first annuloplasty ring (Christenson & Kalangos, 2009). He created the device in an attempt to reduce the size of the mitral valve and as a result decrease the severity of the mitral regurgitation (Lantada et al., 2009). Annuloplasty rings are designed to aid in the repair of the mitral valve. The repair of a mitral valve is preferred over complete replacement. This is mainly due to the fact that the patient is not required to use long term drug therapy following surgery (Buckner et al., 2010). After a valve has been repaired, the annuloplasty ring is sutured onto the patient’s native mitral annulus. The ring not only reconstructs the shape of the mitr...
Endovascular stent graft repair is designed to help reinforce a weakened aorta. Endovascular surgery is performed inside the aorta using thin, long tubes called catheters to place a stent surrounded with a fabric liner. Endovascular stent grafting uses an endovascular stent graft to reinforce the wall of the aorta and to help keep the damaged area from rupturing and developing into a potentially serious health problem that can be fatal and cause massive internal bleeding.
Alumina and zirconia ceramics have been widely used in orthopaedic hip replacements for the past 30 years. The advantage of using these was lower wear rates than those observed using polymers and metals. Because of the ionic bonds and chemical stability of ceramics, they are relatively biocompatible and therefore more preferable to use than metals and polymers. Alumina is most commonly used as a femoral head component instead of a metal in a hip prosthesis because this would reduce the polyethylene wear that is generated. Alumina is a desirable biomaterial to use in hard tissue implants because of characteristics like excellent wear resistance, high hardness, bio inert, low abrasion rate and good frictional behaviour. Furthermore, it has excellent surface finish as well as high fatigue streng...
Prosthetics has become a regular necessity because people need them for different reasons such as illness, mobility purposes and disfigurement.
... the usage of bioresorbable scaffold involves by selecting certain phenotype of cell and implants it on permeable substance before being implanted to the pulmonary position. The scaffold is presume to degenerate as the cells grow. The last approach involves constructing a mold for leaflets similar to the aortic shape using the collagen constructs (Vesely 2005).
Lidwell and Edgar H. Booth invented the first pacemaker. It was a portable device that consisting of two poles, one of which included a needle that would be plunged into a cardiac chamber. It was very crude, but it succeeded in reviving a stillborn baby at a Sydney hospital in 1928. The decades that followed, inventors came up with increasingly sophisticated versions of the pacemaker. However, these devices; which relied upon vacuum tubes; remained heavy and bulky, affording little or no mobility for patients. Colombian electrical engineer Jorge Reynolds Pombo developed a pacemaker in 1958 weighed 99 lbs and was powered by a 12-volt auto battery. Surgeons at the Karolinska Institute in Sweden were the first to place a fully implantable device into a patient in 1958. Rune Elmqvist and surgeon Ake Senning invented this pacemaker, which was implanted in the chest of Arne Larsson. The first device failed after three hours, the second after two days. Larsson would have 26 different pacemakers implanted in him. He died at the age of 86 in 2001, outliving both Elmqvist and Senning. In the world there are many heart attacks and as people grow they can get abnormalities in there heart(Medlineplus). When someone 's heart stops working it can be fixed with a pacemaker, it makes the heart beat properly. The artificial pacemaker is a wonder of modern science. A small, implantable device that regulates a human heartbeat through electrical impulses have saved millions of lives. The development of this vital medical device owes much to the advances in electronics and communications brought about by the Space Age.Pacemakers may be used for people who have heart problems that cause their heart to beat too slowly. A slow heartbeat is called Bradycardia two common problems that cause a slow heartbeat are sinus node disease and heart block. When your heart
In 1596, the world's first flush toilet was invented by Sir John Harrington. The problem was still not solved. All these years people had to throw their waste on the streets, and this would cause the place to stink. I wasn't until 1775; that's when Alexander Cunnings invented the S-valve toilet. This toilet prevented stinky gas from entering the house. People think that Thomas Crapper invented the toilet, but he didn't. He only made and sold them. The S-valve toilet has had a huge impact on today's world.
Prosthesis has evolved from different swirling stages time to time to the more advanced ,mature and sophisticated one after a long chain of memoriable events, the modern and develoed prosthesis is quite different from the archaic prosthesis. It has groomed itself with the running wheel of time. No innovative ideas were involved in the primitive beginnings of prosthesis, instead it became a very natural and essential need of the the persons with missing body organs.