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Results for “HEART VALVE PROSTHESIS”

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At least 19 recordsLinked to original sources
PubMed1991

Principle of operation, design criteria and fluid dynamics of a new bileaflet heart valve prosthesis.

Bileaflet heart valves show the best fluid dynamic behaviour among mechanical valves and, as a consequence, give the best clinical results. A new bileaflet heart valve has been designed whose main characteristics are the kind of leaflet movement, low profile, fluid dynamics and material. Two flat leaflets move freely inside a very low profile housing ring. The movement is described by the rolling without sliding of the leaflet surface around a cylindrical surface on the inner wall of the housing. The opening angle is 85 degrees. Both the leaflets and the housing are machined from a solid piece of titanium and then covered with carbon by ion beam techniques. The design phase and the first fluid dynamic evaluation were done by numerical methods.

Carbon↗
PubMed1989

[Use of anticoagulants in pregnant women carrying heart valve prosthesis].

Prosthetic heart valves require permanent anticoagulant treatment. In the case of pregnancy, serious problems arise in that coumarin drugs lead to increased incidence of fetal death and malformation. On the other hand, the omission of anticoagulant treatment implies considerable risks of systemic embolism and even of maternal death. Review of the literature and the few cases published so far do not prove that antiplatelet agents are effective and safe and offer sufficient protection against thromboembolism. The use of heparin may reduce the incidence of complications. The authors come to the conclusion that women with prosthetic heart valves should be advised to avoid pregnancy. Biovalves should be applied in those who wish to bear children.

Abnormalities, Drug-Induced↗
PubMed1997

Midterm results with the Sorin Monostrut heart valve prosthesis.

OBJECTIVE: To monitor the hematological and clinical sequelae of a single tilting disc cardiac valve prosthesis. DESIGN: Prospective nonrandomized trial. SETTING: University teaching hospital. PARTICIPANTS: All patients receiving a single mechanical cardiac valve prosthesis were offered the Sorin Monostrut valve if they met the criteria for valve use. Seventy-five per cent of the patients entered were in New York Heart Association (NYHA) functional class III or IV. One hundred and forty-seven patients were subsequently followed at three months and then yearly after valve implantation for seven years. MAIN OUTCOME MEASURES: At one year, preoperative indexes of hemolysis were compared with three-month and one-year postoperative values. Actuarial curves for survival, freedom from cerebrovascular events and explantation were constructed for the seven-year follow-up period. RESULTS: Hemolysis, as measured by lactate dehydrogenase values, commonly occurs preoperatively, remaining significantly elevated three months and one year following valve implantation. Serum haptoglobin was normal preoperatively but was significantly low at one year. Anemia was uncommon and most patients had normal reticulocyte counts at one year. At three years, 81% of patients were in NYHA functional class I. CONCLUSIONS: Midterm results show that this valve is structurally reliable and meets all current requirements for a safe mechanical valve.

Adult↗
PubMed1992

A study of the stability of orientation in the CarboMedics bileaflet heart valve prosthesis.

A total of 25 CarboMedics bileaflet prostheses was studied in the immediate postoperative period and at 1 week, 1 month and 3 months after surgery. No evidence of rotation was found on visual comparison of valve orientation and there were no significant differences between successive studies for the distance between the septum and either the anterior (P = 0.92) or posterior leaflet (P = 1.00) of valves in the mitral position. The possibility of spontaneous rotation is a potential drawback not only of the CarboMedics prosthesis, but also of designs currently being developed. This study suggests that major rotation does not occur commonly.

Adult↗
PubMed1999

Recurrent endocarditis in silver-coated heart valve prosthesis.

BACKGROUND AND AIM OF THE STUDY: In order to prevent prosthetic valve endocarditis (PVE), the implantation of a new silver-coated sewing ring has been introduced to provide peri- and postoperative protection against microbial infection. METHODS: A 56-year-old woman with aortic stenosis had elective replacement with a St. Jude Medical mechanical valve fitted with a silver-coated sewing ring (Silzone). The patient developed early PVE, which necessitated reoperation after one month. Despite a second Silzone prosthesis being implanted, the endocarditis recurred. During a third operation an aortic homograft was implanted, and after six months a fourth operation was performed for a pseudoaneurysm at the base of the homograft, in proximity to the anterior mitral valve leaflet. RESULTS: The diagnosis of PVE was confirmed by the presence of continuous fever, transesophageal echocardiography and growth of penicillin-resistant Staphylococcus epidermidis from the valve prosthesis. CONCLUSION: The implantation of all prosthetic valves is encumbered with a risk of endocarditis. Although silver has bacteriostatic actions, the advantages of silver-coated prostheses in the treatment of this condition have yet to be assessed in clinical trials.

Anti-Bacterial Agents↗
PubMed1999

Concentric wear of the Delrin disc in a Bjork-Shiley heart valve prosthesis: report of two cases.

We report herein the cases of two patients who received replacement of aortic Bjork-Shiley Delrin (BSD) valves that had been implanted for over 20 years following the development of aortic regurgitation (AR) resulting from wear of a Delrin disc. Case 1 was a 61-year-old woman in whom echocardiography revealed marked left ventricular dilatation and moderate AR 23 years after an aortic valve replacement (AVR) with a 21-mm BSD valve. Case 2 was a 51-year-old woman in whom echocardiography revealed marked dilation of the right atrium and moderate AR 23 years and 8 months after an AVR with a 21-mm BSD valve, as well as a mitral valve replacement with a 3M Starr-Edwards (SE) ball valve and tricuspid annuloplasty. In both patients, the BSD valves were replaced with other mechanical valves at reoperation. Examination of the explanted BSD valves showed that the Delrin discs contained increases in the radial gaps and strut indentation grooves on the inflow and outflow surfaces. The type and magnitude of the wear on the Delrin discs in these valves were consistent with data reported in the literature for this valve design after similar implant duration.

Aortic Valve↗
PubMedDate not supplied

[Medical-surgical management of left heart valve prosthesis dysfunction due to obstruction. Eleven year's experience].

UNLABELLED: We report the surgical-medical experience in left side mechanic prosthesis cardiac valve dysfunction. From January 1986 to June 1997 we included 108 consecutive patients (pts), 24 were men and 84 women, mean age 45 years, they underwent 114 surgical procedures, 104 in mitral and 10 in aortic position. RESULTS: The dysfunction was due to obstruction in fixed disc in 107 pts and intermitent in 7 pts. The pathological findings were thrombosis in 92 pts, pannus in 9 pts and both in 13 pts. The time interval between valve replacement and dysfunction was from 1 to 247 months, mean 53.8 +/- 56.7. Seventy five percent of patients received inadequate anticoagulant therapy, the mean INR was 2.06 +/- 0.79. In 76% of patients the functional class was III or IV NYHA. The diagnosis was made by clinical and echocardiographic findings in 96% of patients. The surgical procedures included valve replacement in 103, and toilette in 11 pts. The time of extracorporeal circulation in patients who died us survival patients were (159.9 +/- 108.95 vs 87.32 +/- 27.53 min) and aortic cross-clamp (64.8 +/- 20.69 vs 48.28 +/- 23.71 min) respectively (p < 0.001). The overall mortality was 12 pts (10.5%), all in functional class III or IV NYHA (p < 0.05), five patients died during surgical procedure. In conclusion the diagnosis must be established clinically as well as by echocardiography. The risk factors associated with mortality were pulmonary edema, shock, delayed surgery, surgical time prolonged and functional class III or IV NYHA.

Anticoagulants↗
PubMed2003

Transvalvular in vivo gradients of the new generation bileaflet heart valve prosthesis St. Jude Medical Regent in aortic position.

BACKGROUND: By changing the design of the St. Jude Medical Regent prosthesis in shifting both sewing cuff and retaining ring into a completely supra-annular position, the Regent valve has a greater geometric orifice for a given outer diameter. Accordingly, in vitro studies have shown increased effective orifice areas (EOAs) and lower transvalvular gradients. The aim of our study was to determine in vivo transvalvular gradients and EOAs in patients after aortic valve replacement (AVR). METHODS: We investigated 75 patients at 12 to 21 months follow-up after AVR using transthoracic echocardiography. We determined left ventricular systolic and diastolic function, EOA, and transvalvular peak gradient parameters at rest. Outcomes were assessed using the NYHA classification and functional status. RESULTS: No patient experienced cardiac failure. The majority reported good functional status and good quality of life. Five (6.7 %) late deaths were observed within the surveillance period. At follow-up, 92 % of the patients had improved by at least one NYHA class. Transvalvular peak gradients at rest for patients with Regent valves were 25.4 +/- 7.7 mmHg, 19.2 +/- 4.6 mmHg, 15.6 +/- 5.8 mmHg, 14.6 +/- 5.5 mmHg, and 8.5 +/- 2.5 mmHg; EOAs were 1.38 +/- 0.32 cm2, 1.62 +/- 0.49 cm2, 2.24 +/- 0.83 cm2, 2.63 +/- 0.70 cm2, and 3.28 +/- 0.34 cm2 for valve sizes 19 mm, 21 mm, 23 mm, 25 mm, and 27 mm, respectively. CONCLUSIONS: The SJM Regent valve shows excellent in vivo hemodynamics as confirmed by echocardiography. Clinically, 92 % of the patients improved by at least one NYHA class.

Aortic Valve↗
PubMed1977

[Clinical anatomical basis of the pathogenesis of fatal complications in the late periods after heart valve prosthesis].

On the basis of clinico-anatomical analysis of the causes of death in 35 patients following valve prosthetics for rheumatic valvular disease, it was established that cardiac failure was the most frequent cause. Cardiac failure was due to exacerbation of the carditis process on the one hand, and to disorders of the rhythm induced by dystrophy, sclerosis, fibroelastosis, and calcinosis in the cardiac septum on the other. Thromboembolic processes rate second in frequency among the lethal complications. Death from septic complications was rarely encountered, and from causal causes only in individual cases.

Autopsy↗
PubMed1977

[Heart valve prosthesis in congenital heart defects].

The experience of 68 cases of prosthetic valve replacement for congenital heart diseases is presented. The majority of the cases were 57 patients with the Ebstein anomaly and tetralogy of Fallot. In the patients with the Ebstein anomaly the tricuspid valve was replaced, in those with the tetralogy of Fallot--a plastic enlargement of the pulmonary artery trunk and prosthetic replacement of the pulmonary valve with a ball valve or xeno-graft. Original techniques of radical correction of the Ebstein anomaly and tetralogy of Fallot are presented.

Adult↗
PubMed1999

Expanding the use of total mitral valve preservation in combination with implantation of the CarboMedics heart valve prosthesis.

BACKGROUND: Preservation of the mitral valve and subvalvular apparatus was introduced into the clinic in the early sixties, but for two decades the standard technique for mitral valve replacement included excision of both leaflets and their attached chordae tendineae. Lately, increased emphasis has again been placed on retention of the mitral subvalvular apparatus during valve replacement because of its role on left ventricular function. METHODS: We have preserved the valvular and subvalvular mitral apparatus, when possible, in connection with mitral valve replacement during the last seven years and the present investigation (partly prospective and partly retrospective) was done with the aim of making up the results of our mitral preservation technique. In the period between January 1990 and December 1995, 30% of the patients who underwent mitral valve replacement had complete retention of all mitral tissue. In 1996, the percentage had increased to 50, and during the first seven months of 1997, 70% of the patients had complete retention of all mitral tissue. Since January 1997, we have exclusively used the CarboMedics mitral heart valve prosthesis. A total of 56 patients were identified to have had a CarboMedics heart valve prosthesis implanted. There were 33 men and 23 women with a mean age of 63 years, range 23-77 years. Coronary bypass was a concomitant procedure in 22 patients. In seven patients, both the mitral and aortic valves were replaced. A severely altered valve with thickened and or calcified leaflets, stenotic leaflets, or shortened, retracted and thickened chordae tendineae were not a contraindication for the procedure. Calcified plaques were removed. Adhesion between anterior and posterior leaflets was treated with sharp dissection. Valve and subvalvular tissue were preserved. The leaflets were reefed within the valve-sutures and compressed between the sewing ring and the native annulus when implanting the valve prosthesis. Chordal tension on the ventricle was thereby maintained and the chordae pulled away from the valve effluent. Echocardiography with measurement of ejection-fraction was performed preoperatively during the postoperative course in case of cardiac problems and on a routine basis 1 month after surgery and at various intervals when the patient was seen in the outpatient clinic. Left ventricular outflow tract gradients were measured during the postoperative course in case of cardiac problems and routinely 1 month postsurgically. RESULTS: Five patients died in the postoperative period and one patient had transient neurological symptoms. In none of the patients was death or transient neurological symptoms a consequence of the retention of mitral leaflets with subvalvular apparatus. The remaining 51 patients were all alive at follow-up. Postoperative echocardiography demonstrated a preserved left ventricular function and a left ventricular outflow tract without obstruction. CONCLUSIONS: We find that the described technique in combination with implantation of a CarboMedics heart valve prosthesis is very useful even in patients with a severely altered valve, when preserving the mitral leaflets with subvalvular apparatus during valve replacement. The technique is without procedure related complications and preserves left ventricular function without obstructing the left ventricular outflow tract.

Adult↗
PubMed1999

Low-dose oral anticoagulation and antiplatelet therapy with St. Jude Medical heart valve prosthesis.

BACKGROUND AND AIM OF THE STUDY: Since 1986, the St. Jude Medical (SJM) mechanical heart valve prosthesis has been implanted in patients at the authors' institution. We present our experience of low-dose oral anticoagulation and antiplatelet therapy following SJM valve implantation. METHODS: Among 2,585 patients (mean age 40.3 +/- 13.5 years) living in a rural environment, 865 underwent aortic valve replacement (AVR), 1,231 mitral valve replacement (MVR) and 489 double valve replacement (DVR). All patients received 2.5 mg/day warfarin and a combination of antiaggregation therapy (dypridamole 3 x 75 mg/day plus aspirin 100 mg/day), irrespective of their prothrombin time and cardiac rhythm. RESULTS: Postoperatively, 139 adverse events occurred (51 in AVR patients, 58 in MVR, 30 in DVR). Operative mortality rate was 5.9%, 4.7% and 6.1%, respectively, in the three groups (overall mortality rate 5.4%). The most frequent cause of operative mortality was low cardiac output. During follow up, there were 88 anticoagulant hemorrhages (1.2%/patient-year (pt-yr)), 11 paravalvular leaks (0.2%/pt-yr), 52 thromboembolisms (0.7%/pt-yr), 60 mechanical valve thromboses (0.8%/pt-yr) and 78 reoperations (1.1%/pt-yr). These complications occurred in 101 patients after AVR, in 125 after MVR, and in 63 after DVR (4.2%, 3.7% and 4.6% per pt-yr, respectively). Patient age (p = 0.0004), concomitant surgery (p = 0.0017) and late valve-related complications (p = 0.0159) were statistically significant mortality factors after AVR. Previous surgery was a significant risk factor for operative mortality after MVR (p <0.05). Female gender (p = 0.0059) and age (p = 0.017) were significant risk factors for operative mortality after DVR (p <0.01). CONCLUSIONS: Following implantation of the St. Jude Medical mechanical heart valve prosthesis, a fixed dose of 2.5 mg/day warfarin and combined dipyridamole/aspirin provided satisfactory results in terms of thrombosis, embolism and bleeding.

Administration, Oral↗
PubMedDate not supplied

The porcine heart valve prosthesis.

The development of the prosthetic heart valve has led to the evolution of cardiac intensive care units, a better understanding of cardiac function and biocompatible materials, and new surgical procedures. Initial efforts with formaldehyde-fixed valves did not have long-term success. They led to the development of the stabilized glutaraldehyde process (SGP) valve and the flexible stent. The safety and efficacy of a heart valve bioprosthesis has been demonstrated through laboratory and animal experiments. Data on long-term clinical implants are needed to validate the results of these experiments.

Animals↗