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At least 1,063 records · Page 59Linked to original sources
PubMed1994

[Redo valve replacement for primary tissue failure of bioprosthetic heart valve].

We evaluated long-term results of valve replacement with bioprosthesis in 59 patients. Freedom from primary tissue failure and reoperation declined more than seven years after valve replacement. Seven patients underwent repeat operations because of primary tissue failure in our hospital. Their ages ranged from 32 to 54 years, two cases were male and five were female. At repeat operation, mechanical valve prosthesis were implanted to mitral position in all seven patients, tricuspid annuloplasty was added in five patients, and aortic valve replacement was added in one patients. The New York Heart Association (NYHA) functional classifications were grade II for 1 patient, III for 1, and IV for 5 preoperatively. Five patients had severe pulmonary hypertension preoperatively, and three of them were died after operation. The removed bioprostheses showed tears, perforations or calcifications of cusps and commissural detachments.

Adolescent↗
PubMed1994

Early experience with the Jyros bileaflet valve in the mitral position: high incidence of valve thrombosis.

The Jyros valve is a new bileaflet valve with the unusual feature that the hinge is expected to rotate continuously inside the housing. Nine isolated Jyros mitral prostheses were implanted from July to October 1993. All patients survived the surgical procedure and during the follow up underwent transthoracic (TTE) and transesophageal echocardiograms (TEE) for the evaluation of hinge rotation. Neither TTE nor TEE were able to show hinge rotation in any patient at any time. Five patients had prosthetic thrombosis. In the successfully treated with thrombolysis. In the remaining patient thrombolysis was contraindicated. Eight patients are alive; one died of gastro-intestinal bleeding a few months after discharge. The absence of hinge rotation may be the triggering mechanism of valve thrombosis although no explanted prostheses were available for examination. Further studies are necessary to understand the mechanism of valve thrombosis with the Jyros bileaflet prosthesis.

Adult↗
PubMed1994

Comparison of structural valve failure among different 'models' of homograft valves.

Aortic homograft valves are accepted as excellent valve substitutes in the aortic position. Compared to stented bioprostheses, they are considered to have better hemodynamics and a zero or negligible thrombogenicity. Their perceived major single shortcoming is limited durability, but there is apparent broad variation within published data in this respect. Study of the relevant literature reveals important differences between procurement, sterilization and preservation of the individual series refuting any attempt at making a scientifically valid comparison of overall performances. Surgical method and patient selection are further sources of variation among reported long term results. Nevertheless, it appears that (a) cryopreservation produces results at least as good as those of other preservation methods, and (b) the worst results are those of series with the longest follow up. However, the good results with cryopreserved valves are reported in series with limited length of follow up. Because of the many variable factors associated with the use of homograft valves, a comprehensive set of definitions should be introduced, accepted and adhered to in reporting results.

Aortic Valve↗
PubMedDate not supplied

The pulmonary valve. Is it mechanically suitable for use as an aortic valve replacement?

Pulmonary autografts have shown a low incidence of early failure and late structural deterioration when placed in the aortic position yet the potential value of the pulmonary valve as a replacement device has not been widely considered. Since the mechanical suitability of pulmonary valves for the high stress aortic position is unclear, we set out to define and compare the tensile mechanical properties of these two valves. We removed all 72 cusps from 12 fresh porcine aortic and pulmonary valves. Eighteen cusps from each of the two groups were fixed flat in 0.25% glutaraldehyde for greater than 24 hr. Circumferential or radial strips were cut from each cusp creating eight test groups, each with nine specimens. Stress-strain curves for each specimen were obtained using an Instron tensile testing machine. Stress-strain curves were obtained at 2, 10, 50, and 200 mm/min strain rates, each specimen was then strained to fracture. We found pulmonary leaflets were thinner than aortic leaflets (0.49 mm versus 0.67 mm) and glutaraldehyde fixation did not affect this relationship. The elastic moduli were comparable within the fresh and glutaraldehyde fixed treatment groups and within the circumferential and radial strip groups. Radial strips were more extensible than circumferential strips. Tissue viscous properties were similar and glutaraldehyde fixation produced minimal changes in stress relaxation rates. Tissue fracture tests emphasized tissue anisotropy with the failure point depending upon strip orientation. Glutaraldehyde had no effect on fracture stress but strain at fracture doubled due to increased collagen fiber crimping during fixation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[A successful repair of tetralogy of Fallot with aortic valve regurgitation, coronary artery-pulmonary artery fistula and absent pulmonary valve in a 54-year-old man].

A 54-year-old man suffered from tetralogy of Fallot associated with aortic valve regurgitation, coronary artery-pulmonary artery fistula and absent pulmonary valve underwent intracardiac repair. The operation was completed with ligation of the fistula, aortic valve replacement using a SJM 27 A, patch closure of ventricular septal defect (perimembranous outlet type) and right ventricular outflow reconstruction using a large transannular monocusped-patch, 4 cm x 6 cm in size. Postoperative course was uneventful and he is doing well now. There was no previous reports about TOF associated with AR, the absent pulmonary valve and the coronary anomaly in the adults in the literature.

Aortic Valve Insufficiency↗
PubMed1993

Current perspectives on prosthetic heart valves and valve repair.

The quest for the ideal cardiac valve substitute represents a highly categorized goal for the cardiac surgical community. Ongoing research has resulted in the development and creation of multiple newer heart valves and techniques for valve repair. Each of the many valves commercially available possesses a wide array of features. With the expansion of research investigations, improvement in long-term management can be translated and incorporated directly into patient care. As valvular replacement and repair/reconstruction surgery become more commonplace, it is paramount for nurses to be knowledgeable regarding the critical components of care.

Bioprosthesis↗
PubMed1995

[Possibility for clinical use of mitral valve allograft: an experimental histopathological study in consideration with aortic valve allograft].

Morphologic studies were made on antibiotic preserved mitral valve allograft implanted in 8 sheep for 12 to 24 weeks. All allograft showed severe deterioration of connective tissue due to autolysis and immunological/inflammatory reactions. Compared with aortic valve allograft, mitral valve allograft failed more quickly and more severely, presumably because of differences in structure (presence of chordae tendineae and increased surface area of leaflets) and in closing pressure. The durability of cardiac valve allograft is influenced by the degree of preservation of collagen and elastic fibers in the graft. attenuation of immunologic reactions and control of fibrous sheathing.

Animals↗
PubMed1997

[Mitral valve insufficiency caused by tendinous cord rupture and mitral valve aneurysm. Significance of the echocardiographic study].

Mitral valve aneurysm is a rare complication that may occur in a myxomatous valve. We report the case of a 73 year old male patient with severe mitral regurgitation and heart failure-class IV NYHA. Echocardiography showed perforation of an aneurysm of the anterior leaflet of the mitral valve associated with rupture of tendinous cords of the posterior mitral leaflet. Diagnosis was made by transthoracic echocardiography and confirmed by transesophageal echocardiography. The patient was urgently operated with success and a mitral valve prosthesis was implanted.

Aged↗
PubMed2001

Eight-year hemodynamic follow-up after aortic valve replacement with the Toronto SPV stentless aortic valve.

The hemodynamic performance of stentless aortic bioprostheses has been well described during the first few months after surgery. The purpose of the present study was to describe the hemodynamic performance of the Toronto SPV valve (St. Jude Medical, Inc, St. Paul, MN) in a multicenter trial through 8 years. The long-term study of the Toronto SPV valve includes 447 consecutive patients from 6 investigative centers. Echocardiographic follow-up was performed at specified intervals, with quantitative analysis performed at a centralized core laboratory. Mean transvalvular gradient decreased significantly between discharge and 6 months, between 6 months and 1 year, and between 1 year and 2 years after surgery, without further significant change. The effective orifice area increased significantly early after surgery and continued to increase through 6-year follow-up. The left ventricular (LV) stroke volume increased progressively from discharge through 6-year follow-up. The LV mass index decreased significantly from discharge through 3 years after surgery and stabilized through 5 years. There was a gradual increase in LV outflow tract diameter between 1 year and 6 years after surgery. The prevalence of any aortic regurgitation (AR) (including trivial) and > or = mild AR increased significantly between discharge and 6-year to 8-year follow-up. However, the prevalence of > or = moderate AR remained very low at 6 years (2.6%) and 8 years (4.5%) after surgery. In conclusion, the Toronto SPV stentless tissue aortic valve is associated with excellent hemodynamics early after surgery and through 8 years after surgery. LV mass decreases early, and returns to within the range of normal by 1 year after surgery. There is evidence of continued LV mass regression involving the LV outflow tract, potentially contributing to a small but significant late improvement in hemodynamics. The prevalence of significant AR remains low through 8 years.

Adult↗
PubMed1987

[Hemolysis indicators in the evaluation of the function of artificial heart valves after heart valve prosthesis].

Hemolysis of blood was studied in two groups of patients: the main group consisted of 75 patients with mitral, aortal and two-valves prostheses; a control group had 15 patients with rheumatic valve defects without prostheses. It was shown that hemolysis was minimal in patients with a satisfactory function of prostheses. It was higher after double prostheses and especially in patients with dysfunction of the valves. Lactate dehydrogenase is thought to be the most important and reliable test for the assessment of the hemolysis degree.

Adult↗
PubMed1984

[Radionuclide ventriculography in aortic and mitral valve insufficiency. Pre- and post-operative studies of valve replacement surgery].

Radionuclide ventriculography (RNV) is now a well-established procedure for the noninvasive evaluation of cardiac hemodynamics, including the detection and quantification of valvular regurgitation. 46 patients undergoing aortic or mitral valve replacement were examined by RNV pre- and postoperatively. The specificity of RNV in the diagnosis of aortic or mitral incompetence was high. All cases of moderate to severe aortic regurgitation were identified. This, however, was not true for mitral incompetence. A significant overlap between the left atrium and the left ventricle in the LAO view is held responsible for this decrease in sensitivity. The quantification of aortic regurgitation and the assessment of left ventricular function by RNV appears to hold promise in the preoperative workup. This diagnostic approach yields important additional information, which may be essential in the appropriate timing of surgical intervention. Aortic valve replacement for incompetence as well as for stenosis was accompanied by a significant improvement in global left ventricular ejection fraction. No postoperative change in ejection fraction was found in cases of mitral incompetence, while a slight increase was observed following operative therapy for mitral stenosis. The radioisotope findings were correlated to the results obtained by cardiac catheterization and noninvasive techniques such as echocardiography. The place of RNV in the pre- and postoperative management of valvular heart disease is delineated in this paper. It is of special value in the evaluation of aortic incompetence and may be an important diagnostic adjunct in the approach to the patient with mitral valve disease or aortic stenosis.

Adult↗
PubMed2006

Percutaneous replacement of pulmonary valve using the Edwards-Cribier percutaneous heart valve: first report in a human patient.

We report on the use of the Edwards-Cribier percutaneous heart valve (PHV) in a stenotic right ventricle to pulmonary artery homograft in a 16-year old patient who underwent the Ross operation. Initially, the homograft was stented and at the same procedure, the PHV was deployed inside it. This is the first human case of the application of this valve in the pulmonary valve position.

Adolescent↗
PubMed2006

[Aortic valve stenosis: from valvuloplasty to percutaneous heart valve].

Calcified aortic stenosis is the predominant valve disease. Patients affected are most commonly elderly people, who often show associated comorbidities like reduced left ventricular function, impaired renal function, and pulmonary hypertension. The risk of open-heart surgery is elevated. Balloon aortic valvuloplasty enables a reduction of symptoms, an increase in physical performance, and, therefore, an improved quality of life. However, a reduction in mortality cannot be reached with this method. New techniques and improved equipment induced a "revival" of balloon aortic valvuloplasty, which has been introduced almost 20 years ago. In addition, brachytherapy after balloon valvuloplasty has recently been investigated and represents an interesting approach to reduce early restenosis. The technical improvement of balloon valvuloplasty is the percutaneous heart valve, which is under present clinical investigation. The antegrade/transseptal and retrograde approaches are used, as is the transapical access to the left ventricle. Even if long-term results are not yet available and the procedures still require technical improvement, especially minimization of catheter size, percutaneous valve replacement is a new chapter in the treatment of the calcified aortic stenosis.

Age Factors↗
PubMed1988

Aortic valve disease and the ST segment/heart rate relationship: a longitudinal study before and after aortic valve replacement.

The ST segment/heart rate relationship or maximal ST/HR slope has been validated as an index of myocardial ischemia in selected populations of patients with angina pectoris. The present study involved patients selected as having aortic valve disease unaccompanied by angiographic coronary artery narrowing. In each of seven patients, so far examined, a slope value and ST segment depression of greater than 1 mm were obtained which, according to previous experience, indicated myocardial ischemia equivalent to coronary heart disease. After aortic valve replacement, there was a significant reduction in heart size as assessed using the cardiothoracic ratio, and the amplitude of QRS complex on the electrocardiogram. The slope was abolished (two patients) or markedly reduced (five patients), and the decrease in the seven patients was statistically significant. ST segment depression could be obtained in one patient. This study has shown the occurrence of maximal ST/HR slope in patients without large coronary artery disease who have aortic valve disease and cardiac enlargement.

Aortic Valve↗
PubMed1970

Immediate and long-term results of aortic valve replacent with University of Cape Town aortic valve prosthesis.

Aortic valve replacement with the University of Cape Town lenticular prosthesis was performed in 149 patients during a six-year period, almost all patients being severely disabled with advanced heart disease. There was a hospital mortality of 12 per cent. Bacterial endocarditis was a serious complication and accounted for three hospital and five long-term deaths. The survivors were followed for periods of up to 72 months (average 24), the minimum period of observation being six months. There were 23 late deaths due to heart disease, of which 5 where due to myocardial failure. Myocardial failure unrelieved or only temporarily alleviated by the operation occurred in three surviving patients. The main problems have been sudden death and systemic embolism. Some of the cases of sudden death were due to coronary artery embolism, but in a number the cause could not be determined even at necropsy, and they were presumed to be due to arrhythmia. Both complications appeared to be related to valve design. A bare steel seat was associated with a high incidence of both complications, whereas a woven Dacron-velour cloth-covered seat almost eliminated embolism and reduced the incidence of sudden death. Long-term anticoagulant therapy appears to be of no real value with the cloth-covered valve. Gratifying results were obtained in the surviving patients with loss of all symptoms in 80 per cent and improvement in almost all patients. This improvement or relief of symptoms was maintained in most patients throughout the period of study.

Adolescent↗
PubMed2003

Impact of valve prosthesis-patient mismatch on short-term mortality after aortic valve replacement.

BACKGROUND: The prosthesis used for aortic valve replacement (AVR) can be too small in relation to body size, thus causing valve prosthesis-patient mismatch (PPM) and abnormally high transvalvular pressure gradients. This study examined if there is a relation between PPM and short-term mortality after operation. METHODS AND RESULTS: The indexed valve effective orifice area (EOA) was estimated for each type and size of prosthesis being implanted in 1266 consecutive patients and used to define PPM as not clinically significant if >0.85 cm2/m2, as moderate if >0.65 cm2/m2 and 120 minutes (P=0.001), and PPM (P=0.003). Relative risk of mortality was increased 2.1-fold (95% confidence interval, 1.2 to 3.7) in patients with moderate PPM and 11.4-fold (4.4 to 29.5) in those with severe PPM. Moreover, risk of mortality for every category of PPM was higher in patients with a left ventricular ejection fraction <40% as compared with >or=40% (nonsignificant PPM, 2.7 versus 1.0; moderate PPM, 7.1 versus 1.8; severe PPM, 77.1 versus 11.3). CONCLUSIONS: PPM is a strong and independent predictor of short-term mortality among patients undergoing AVR, and its impact is related both to its degree of severity and the status of left ventricular function. In contrast to other risk factors, moderate-severe PPM can be largely avoided with the use of a prospective strategy at the time of operation.

Aged↗
PubMed1989

Left ventricular myocardial structure in aortic valve disease before, intermediate, and late after aortic valve replacement.

Left ventricular biplane cineangiography, micromanometry, and endomyocardial biopsies were performed in 27 patients with aortic stenosis (AS) and in 17 patients with aortic insufficiency (AI). Twenty-three patients with AS and 15 with AI were restudied at an intermediate time (18 months after successful valve replacement), and nine patients with AS and six with AI were restudied late (70 and 62 months after surgery). Biopsy samples were evaluated for muscle fiber diameter, percent interstitial fibrosis, and volume fraction of myofibrils. In control biopsy samples obtained from five donor hearts at transplantation, these morphometric variables averaged 21.2 microns, 7.0%, and 57.2%, respectively. After surgery, mass determined by cineangiography decreased from 186 to 115 and 94 g/m2 in patients with AS and from 201 to 131 and 93 g/m2 in patients with AI. At the three studies, muscle fiber diameter was 30.9, 28.0, and 28.7 microns in patients with AS and was 31.4, 27.6, and 26.4 microns in patients with AI. Percent interstitial fibrosis was 18.2, 25.8, and 13.7% in patients with AS and was 20.4, 23.7, and 19.2% in patients with AI. Left ventricular fibrous content decreased from 34.2 to 29.8 and to 12.7 g/m2 in patients with AS and from 42.1 to 28.9 and to 18.9 g/m2 in patients with AI. Volume fraction of myofibrils was 57.7, 56.8, and 49.0% in patients with AS and was 56.8, 56.6 and 48.8% in patients with AI. Thus, the decrease of muscle mass determined by cineangiography at the intermediate time after valve replacement is mediated by regression of myocardial cellular hypertrophy in patients with AS and AI and in addition by a decrease of fibrous content in patients with AI. Late after surgery, left ventricular fibrous content also decreases in patients with AS. This late decrease associated with minor changes of end-diastolic volume may be important for improvement of increased diastolic myocardial stiffness. Even 6-7 years after valve replacement, incomplete regression of structural abnormalities of left ventricular hypertrophy still exists compared with the normal myocardium. The residually increased relative interstitial fibrosis and the small late postoperative decrease of volume fraction of myofibrils, associated with a prosthesis-related slight left ventricular pressure increase, are at the origin of a persistent systolic overload at the myofibrillar level.

Adult↗