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At least 235 records · Page 13Linked to original sources
PubMed2003

Clinical evaluation of shunt implantations using Sophy programmable pressure valves: comparison with Codman-Hakim programmable valves.

We describe our experience with Sophy programmable valve shunts, compared with Codman-Hakim programmable shunts in cases with normal pressure hydrocephalus (NPH) after subarachnoid hemorrhage (SAH). A total of 147 consecutive patients underwent 204 shunt implantations (102 Sophy valves, 51 Codman-Hakim valves, 51 nonprogrammable valves). Of these, 23 Sophy and 25 Codman-Hakim valves respectively were implanted into patients with NPH after SAH. Comparison of reprogramming rate and frequency in cases with NPH after SAH between Sophy and Codman-Hakim valves revealed similar reprogramming rates (65.2 vs. 64.0%) but a higher frequency with the former (1.70 vs. 1.08 times/person). The mean difference between initial and final pressure was 65.3+/-45.8mmH(2)O in cases with Sophy valves, and 25.0+/-14.1mmH(2)O with Codman-Hakim valves. The average period which was required to determine the final pressures with Sophy and Codman-Hakim valves were 56.5+/-45.0 days and 43.3+/-45.7 days, respectively. Total incidence of complications of Sophy and Codman-Hakim valve shunt systems in cases with NPH after SAH were 26.1% (6/23) and 16% (4/25), respectively. Total instances requiring shunt revision with Sophy valves in cases of NPH after SAH were 6 of 23 (26.1%), while for Codman-Hakim valves the figure was 2 of 25 (8.0%). Sophy, as well as Codman-Hakim programmable valve shunts, allow alteration of opening pressure after the implantation according to patients' conditions, which may contribute to reduction of revision. Similar reprogramming rates but lower frequency, and smaller difference between initial and final pressure in Codman-Hakim valves may be ascribed to finer pressure ranges and ease of reprogramming, which facilitates earlier reprogramming and decisions regarding final optimal opening pressure.

Aged↗
PubMed2000

Urodynamic findings in boys with posterior urethral valves after treatment with primary valve ablation or vesicostomy and delayed ablation.

PURPOSE: Primary valve ablation and temporary vesicostomy with delayed valve ablation are alternative initial management procedures in neonates and infants with posterior urethral valves. To investigate whether initial vesicostomy followed by delayed valve ablation and simultaneous vesicostomy closure may lead to more alterations in bladder function than primary valve ablation only we retrospectively compared postoperative urodynamic findings in 2 small groups of patients. MATERIALS AND METHODS: From 1980 to 1990, 15 male infants 19 days to 34 months old with posterior urethral valves were treated with 1 of 2 initial surgical approaches, including valve ablation only in 8 (group 1), and primary vesicostomy and delayed valve ablation associated with concomitant vesicostomy closure in 7 (group 2). Mean age at valve ablation and vesicostomy in groups 1 and 2 was 10.8 +/- 11.2 months (range 1 to 35) and 55.4 +/- 43.3 days (range 19 to 151), respectively. Average duration of vesicostomy diversion was 33.6 +/- 18.8 months (range 14 to 70). All patients underwent conventional urodynamics postoperatively using normal saline at room temperature. In groups 1 and 2 mean age at followup was 11.5 +/- 6.6 (range 5 to 16.2) and 9. 4 +/- 3.1 (range 4.10 to 14) years, respectively. Controls comprised 46 age matched males who underwent urodynamics using similar methodology. RESULTS: Postoperative urodynamic assessment of maximum cystometric bladder capacity and the incidence of detrusor instability in each treatment group were not statistically different. In group 1 bladder capacity was significantly higher than that in controls (p <0.0001). In group 2 mean end filling detrusor pressure was increased compared with that in group 1 (29 cm. water, range 15 to 60 versus 8, range 4 to 21). Compliance was significantly lower in group 2 than in group 1 (p <0.0005). Analysis of detrusor voiding pressure at maximum flow was not significantly different in the 2 groups. We noted detrusor under activity in 1 group 1 and 2 group 2 cases. In these patients post-void residual urine volume was 8% to 66% of cystometric bladder capacity. However, only 1 of these 3 patients who required augmentation cystoplasty needed intermittent catheterization. Urodynamic patterns of outflow obstruction developed in 1 patient in each group, including urethral stricture and bladder neck obstruction. At followup we observed no difference in renal function impairment in the 2 groups. CONCLUSIONS: Our retrospective study of rapid filling cystometry suggests that primary valve ablation for posterior urethral valves is associated with a better bladder function outcome than that in patients treated with vesicostomy and delayed valve ablation. Therefore, although cutaneous vesicostomy may be performed as initial management of posterior urethral valves, primary valve ablation is the most effective surgical option in these cases.

Adolescent↗
PubMed1994

Tricuspid valve replacement with the St. Jude Medical valve.

A study was conducted on 20 patients who underwent tricuspid valve replacement (TVR) with the St. Jude Medical (SJM) valve. Isolated TVR was performed on 9 patients, and additional mitral, or mitral and aortic valve replacements were performed on 11 patients. Four patients (20%) died in the early postoperative period, but there were no deaths related to the SJM valve in the tricuspid position. The mean follow-up period of the 16 survivors was 74.4 months, and there have been no deaths during the follow-up period. The postoperative actuarial survival rate was 80%, 10 years after surgery. Three patients, representing 0.25%/patient-months, developed valve thrombosis, the valve thrombosis-free rate being 72.8%, 10 years after surgery, while entrapment of a leaflet by endothelial pannus was found in one patient, representing 0.08%/patient-months. Thus, the incidence of all prosthetic valve-related complications was 0.34%/patient-months, and the postoperative complication-free rate was 65.3%, 10 years after surgery. The medium-term follow-up study of TVR with the SJM valve revealed no prosthetic valve-related deaths and a relatively low incidence of prosthetic valve-related complications. However, as with other mechanical valves, valve thrombosis was a major risk posed by the SJM valve in the tricuspid position.

Actuarial Analysis↗
PubMed2006

Allogenic heart valve bank in the Department of Cardiovascular Surgery and Transplantology of Jagiellonian University in Cracow - 23 years experience in the treatment of aortic valve or aortic root diseases.

Allogenic aortic valves are widely used in case of native aortic valve or root disease as well as failed prosthetic valves with great success. At the Department of Cardiovascular Surgery and Transplantology of the Jagiellonian University in Cracow, aortic valve or aortic root replacement with allogenic aortic valve has been performed for 23 years. Allogenic heart valve bank was founded in 1980. In the bank we prepare both aortic allografts for adult cardiac surgical procedures and pulmonary allografts that are mostly used for repair of congenital heart disease.Allogenic aortic valves implantation was usually considered in our clinic for older patients, patients with infective endocarditis of the native or prosthetic valve, young women in reproductive age and patients with Marfan syndrome. Allografts exhibit excellent clinical performance and acceptable durability with no early failure if properly inserted. Between 1980 and 1992, allografts were obtained only from cadavers during routine autopsies. More than 10% of prepared allografts were exported to other cardiac surgery centres in Poland and foreign countries. Aortic valve replacement using allogenic aortic valves can be performed with acceptable mortality and good long-term results. The procedure although surgically more challenging has the advantage of not requiring anticoagulation therapy, hemodynamic performance of the allogenic valve is excellent, it demonstrates freedom from thromboembolism and infective endocarditis. We would like to emphasize the importance and advantages of the fact that allogenic heart valve bank is placed in the department of cardiovascular surgery and it is able to supply the department in heart valve allografts 24 h a day.

Adolescent↗
PubMed2007

Concomitant aortic valve replacement and coronary bypass: the effect of valve type on the blood flow in bypass grafts.

OBJECTIVE: In cases of aortic valve replacement, the downstream flow profile and turbulence in the ascending aorta differ according to the prosthetic aortic valve implanted. The objective of this work is to study the influence of prosthetic valve type on the flow in the bypass grafts implanted to the ascending aorta in cases of concomitant aortic valve replacement and coronary artery bypass. METHODS: The study is conducted on 456 patients receiving concomitant aortic valve replacement and coronary bypass vein grafts anastomosed to the ascending aorta. The patients included in the study received a total number of 725 vein grafts, 249 biological aortic valves and 207 mechanical aortic valves. Intraoperative transit time flow measurement was done for all bypass grafts and a multiple regression model was calculated for the factors influencing the flow in the bypass grafts. RESULTS: The mean flow in vein grafts in patients receiving biological valves was 49.79+/-26.88 ml/min, while in patients receiving mechanical valves it was 46.54+/-26.68 ml/min. The multiple regression model revealed that receiving a mechanical valve is an independent risk factor for lower flow in the vein grafts. CONCLUSIONS: The type of the aortic valve implanted and consequently the downstream flow profile in the ascending aorta do affect the flow in the vein grafts in cases of concomitant aortic valve replacement and coronary bypass. Receiving a mechanical aortic valve is an independent risk factor for lower flow in the vein grafts.

Aged↗
PubMed1992

Aortic valve regurgitation and the congenitally bicuspid aortic valve: a clinico-pathological correlation.

OBJECTIVE: To investigate the morphology of congenitally bicuspid aortic valves causing pure valve regurgitation. DESIGN: A case series collected over five years. SETTING: An academic hospital. PATIENTS AND METHODS: One hundred and forty eight excised congenitally bicuspid aortic valves. The morphological findings were correlated with sex, age, clinical history, and data on haemodynamic function before operation. Pure valve regurgitation was defined as grade 3-4/4 with a gradient less than 30 mm Hg. Aortic root dilatation was evaluated angiographically or echocardiographically or both. RESULTS: Three types were recognised: valves that were purely bicuspid (23%), bicuspid valves with a raphe (34%), and valves with an additional indentation of the free edge of the conjoined cusp (43%). In 14 cases pure valve regurgitation was present. Dilatation of the aortic root was present in 47 cases. The relative risk for regurgitation when the aortic root was dilated (compared with no dilatation) was 3.99. The relative risk for valve regurgitation when there was indentation of the conjoined cusp (compared with no indentation) was 4.95. The mean age at operation in patients with pure regurgitation was 56 years, which is significantly younger (p = 0.0008) than that of patients with a congenitally bicuspid valve with combined valve stenosis and regurgitation (64.7 years). CONCLUSIONS: Congenitally bicuspid aortic valves with a central indentation of the free edge of the conjoined cusp seem particularly likely to develop pure aortic valve regurgitation.

Adult↗
PubMed1982

Effect of glutaraldehyde fixation and valve constraint conditions on porcine aortic valve leaflet coaptation.

In an investigation of the influence of glutaraldehyde fixation pressure and subsequent valve constraint on the coaptive characteristics of porcine aortic valves, 14 valves were examined, eight having been fixed at low pressure (congruent to 1 mm Hg) and six at high pressure (80 mm Hg). The coaptive ratios of the left and right coronary leaflets in the low-pressure-fixed valves showed a significant improvement over those of the same leaflets in the high-pressure-fixed valves. Inflation to 80 mm Hg results in a variable "peeling back" of the coaptive margins of the low-pressure-fixed valves but not of the high-pressure-fixed valves. Comparable coaptive ratios are therefore expected during full inflation of the unconstrained valves fixed both at low pressure and at high pressure. Constraining the low-pressure-fixed valves during inflation to simulate the effect of mounting on a rigid stent produced either a reduction or virtual elimination of this "peeling back" motion or in some instances a slight reversal of the effect, thus increasing the width of the coaptive margin. Hence it is expected that the stented low-pressure-fixed valve will manifest better coaptation than the high-pressure-fixed valve. Finally, the experimental findings of this study, combined with the improved mechanical function of the leaflet tissue already known to occur in the low-pressure-treated valves, provide a convincing case for valve fixation to be carried out under lower pressures.

Animals↗
PubMed1990

Preferability of bioprostheses for isolated aortic valve replacement--a comparative study between mechanical and bioprosthetic valves.

Comparative long-term performance characteristics of mechanical valves and bioprosthetic valves were analyzed retrospectively among patients who had undergone isolated aortic valve replacement between 1968 and 1987. One hundred sixty-seven patients received either mechanical (n = 82) or bioprosthetic (n = 85) valves. The cumulative follow-up was 926 patient-years (mean 6.1 +/- 4.7 years, ranging from 0.5 to 20.2 years, 100% complete follow-up). Actuarial survival rate, including operative death, at 10 years was 74 +/- 7% for mechanical and 77 +/- 7% for bioprosthetic valve recipients. The rates of freedom from thromboembolism, structural valve failure, prosthetic valve endocarditis, and valve re-replacement at 10 years were 77 +/- 7%, 100%, 96 +/- 2% and 95 +/- 3% for mechanical, and 94 +/- 4%, 83 +/- 8% (p less than 0.05), 88 +/- 5% and 75 +/- 8% (p less than 0.05) for bioprosthetic valve recipients, respectively. Thromboembolism occurred more frequently in the mechanical valve recipients (p less than 0.01), and structural valve failure in the bioprostheses recipients (p less than 0.05). There was no mortality at the time of valve re-replacement. Most of the bioprosthesis recipients received no anticoagulation therapy beyond 3 months postoperatively. Cardiac medication in the late postoperative period was not required in 31.3% of bioprosthetic, and 3.2% of mechanical valve recipients (p less than 0.01). These results show that bioprosthesis in the aortic position exhibits a superb antithrombogenicity and may enable a drug-free state, though its limited durability requires reoperation.

Actuarial Analysis↗
PubMed1998

Spectral analysis of heart valve sound for detection of prosthetic heart valve diseases.

The spectral analysis of heart valve sound is a noninvasive diagnostic method known to be useful in evaluating the state of the heart valve function. This may provide early detection of valve calcification, thrombus or destruction, since previous studies have shown that the dominant frequency peak moved to a high frequency area when natural heart valve leaflets were calcified, stiffened or destroyed. However, it is important for a heart valve sound diagnostic system to find a proper spectral analysis method on phonocardiography. Until now, conventional frequency analyses such as the Fourier transform or autoregressive spectral estimation technique have been used to estimate spectral components of a phonocardiogram, but they are inappropriate because the signal frequency is assumed to remain constant during the transform interval. To overcome this problem, in this study, FOS (Fast Orthogonal Search) & MUSIC (MUltiple SIgnal Classification), which both appeared suitable for the analysis of biological data, were applied to prosthetic heart valve sound as the new heart valve sound spectral analysis methods. Five subjects with normally functioning mechanical heart valves and a patient with a malfunctioning one were selected to collect the heart valve sound signals. As a result, the second dominant peak frequency proved to be important along with the first dominant peak frequency in identifying the valve function. This study showed that the new heart valve sound spectral analysis method presented in this paper may be an effective method in heart valve sound analysis. Further study using this system in a large population of patients will aid in providing a diagnostic method in the early detection of valve failure.

Female↗
PubMedDate not supplied

Homograft valve bank: our experience in valve banking.

BACKGROUND: A cardiac homograft valve bank with cryopreservation facility was established at the Institute of Cardiovascular Diseases, Madras Medical Mission, Chennai in July 1995. METHODS AND RESULTS: During the last 7 1/2 years of its existence, from July 1995 to March 2003, 588 hearts were processed. The valves harvested were 390 aortic, 400 pulmonary and 39 others including mitral valve, aortic conduits, pericardium etc.; 176 (29.9%) hearts were discarded for various reasons which included failure to sterilize, HBV, HIV, HCV, treponema pallidum hemagglutination test positivity, atheromatous/fatty streaks, incompetent valves, and dissection mistakes. The valves were sterilized using an antibiotic cocktail of vancomycin, amikacin, streptomycin, cefotaxime and amphotericin B in Hank's balanced salt solution. Of the 585 valves issued for clinical use, 247 were aortic, 323 pulmonary and 15 others (mitral valve, pericardium, conduits). Gram negative bacilli were the predominant contaminants from the hearts during the first half (July 1995 to February 1999) and gram positive organisms were the predominant contaminants during the later half (March 1999 to March 2003) of the study period. A variety of fungal contaminants like candida, aspergillus, penicillium and other fungi were also isolated from the homograft hearts at procurement. The valves were used most commonly for Rastelli procedure/right ventricular-pulmonary artery conduit (48.71%) followed by Ross procedure (23.41%). The other procedures were aortic valve replacement (6.15%), truncus repair (5.81%), unifocalization with conduit repair (6.49%), aortoplasty (0.512%), left ventricular-pulmonary artery conduit (0.512%), pulmonary valve replacement (0.512%), aneurysm repair (0.34%), Norwood repair (0.34%), mitral valve replacement (0.17%) and other procedures (7%). CONCLUSIONS: We have established a viable and functioning cardiac homograft valve bank to suit Indian conditions and till date, have issued 585 homograft valves for clinical use.

Cryopreservation↗
PubMed1995

Aortic valve replacement with the Jyros bileaflet prosthetic valve; early echocardiographic and radiological evaluation.

The Jyros bileaflet prosthetic heart valve has a unique hinge mechanism permitting rotation of the leaflets within the valve ring. Thirty patients undergoing aortic valve replacement with a Jyros valve were assessed clinically, echocardiographically and radiologically. Rotation of the valve in vivo was assessed, as well as the hemodynamic characteristics of the valve at rest and after exercise, and functional capacity of the valve recipients. Measured transvalvar gradients were comparable with other bileaflet valves at rest and after exercise, as were calculated effective orifice areas. Initially only four prostheses (13%) showed any evidence of rotating, but this improved to 14 of 23 investigated (60.9%) after exercise; rotation appears to be more common in smaller valves. There were no operative or early deaths, but one patient died at 11 months from a type A ascending aortic dissection. During a total of 28.5 patient-years of follow up (range 2-24 months) valve related complication has not been reported. All survivors are in good clinical condition. Preliminary results with the Jyros valve compare well with other bileaflet devices for aortic valve replacement; the hemodynamic performance of the valve does not appear to be affected by rotation or non-rotation.

Activities of Daily Living↗
PubMed1996

In vitro assessment of prosthetic valve function in mitral valve replacement with chordal preservation techniques.

BACKGROUND AND AIM OF THE STUDY: The importance of chordal preservation techniques in maintaining improved left ventricular function after mitral valve replacement has been well documented clinically. Currently, the choice of prosthetic valve used in chordal preservation is dependent upon the surgeon's preference. However, the transvalvular flow characteristics of common, clinically used prosthetic valves may be influenced by the mitral subvalvular apparatus, and may result in degraded valve function. The goal of this study was to perform an in vitro evaluation of the influence of chordal preservation on the transvalvular and left ventricular flow patterns of common valve prostheses. METHODS: Tissue and mechanical valves have been evaluated under physiologic pulsatile flow with anterior and/or posterior chordal preservation. Flow patterns were assessed by 2-D planar flow visualization, pulsed wave Doppler velocity measurements, 2-D echocardiography, and selected color Doppler flow mapping. Based on changes in transvalvular and left ventricular flow patterns, favorable prosthetic valve/chordal preservation combinations were identified. Additionally, valve orientation was varied to determine optimal orientation. RESULTS: Baseline results without chordal preservation indicate that the anti-anatomic orientation is preferred for the bileaflet valve design while the tilting disc valve should be oriented with the major axis toward the posterior (free) wall of the ventricle, corroborating published conclusions by other investigators. Some form of flow restriction is observed in all test cases with chordal preservation due to the presence of the subvalvular tissue. In general, bioprostheses showed less flow restriction then the mechanical valves, particularly with lateral flow expansion. This flow restriction may influence pressure recovery downstream of the mechanical valves tested. Increased flow constriction is observed with anterior and posterior chordal preservation. CONCLUSIONS: This study favors the use of the St. Jude Medical bileaflet valve orientated in the anti-anatomic position, or the Carpentier-Edwards pericardial valve with chordal preservation.

Bioprosthesis↗
PubMed1964

REPLACEMENT OF THE AORTIC AND MITRAL VALVES USING THE STARR-EDWARDS BALL-VALVE PROSTHESIS: A REPORT OF 50 CASES.

The aortic and mitral valves were replaced in 50 patients at the University of Alberta Hospital using the Starr-Edwards ball-valve prosthesis. The basis of the selection of 20 patients for isolated aortic valve replacement and 27 for mitral valve replacement using this type of prosthesis is presented, and the techniques of insertion of the aortic and mitral valve are described in detail. Of the 27 patients in whom the mitral valve was replaced by the Starr-Edwards prosthesis six died within 30 days of surgery and two after discharge from hospital at two and a half and four months, respectively. Left atrial thrombosis was the cause of death in four of these patients. In 20 patients in whom the aortic valve was replaced, four died in hospital and two died more than 30 days after returning home. Three of these six patients died from bleeding-the result of the use of anticoagulants. The difficulty in assessing whether or not anticoagulants are needed following replacement by a Starr-Edwards prosthesis is considered. It is felt, in our present state of knowledge, that anticoagulants should be used following mitral valve replacement but are probably not essential following replacement of the aortic valve. Two patients survived replacement of both aortic and mitral valves and have been followed up 18 months and seven months, respectively.

Anticoagulants↗
PubMed1995

Perioperative assessment of aortic homograft, Toronto stentless valve, and stented valve in the aortic position.

We investigated aortic valve hemodynamic performance and perioperative left ventricular function in 50 patients (mean [+/- SD] age, 64 +/- 9 years; 34 men, 16 women) undergoing elective aortic valve replacement, using an aortic homograft (n = 20), a Toronto stentless porcine valve (n = 20), or a stented bioprosthesis (n = 10), by transesophageal echocardiography combined with high-fidelity cavity pressure recordings and thermodilution cardiac output measurements. Thirty-nine patients had aortic stenosis; 11 had predominant regurgitation. Thirteen patients with concomitant coronary artery stenosis underwent grafting. Left ventricular mass index in all patients was 280 +/- 110 g/m2. The transvalvular pressure drop and energy consumption were significantly higher with stented than stentless valves (5 with aortic homograft and 11 with Toronto valve, with matched age and valve size; 20 +/- 12 versus 3 +/- 9 mm Hg; 21% +/- 13% versus 8% +/- 8%, both p < 0.01). However, there was no difference in these variables between the Toronto valve and the aortic homograft (3 +/- 12 versus 2 +/- 10 mm Hg; 5% +/- 14% versus 2% +/- 12%, both p > 0.05), although the Toronto valves (normalized to body surface area) were larger than the aortic homografts (14.4 +/- 1.9 versus 12.6 +/- 1.8 mm/m2, p < 0.01). There was no significant difference in left ventricular stroke volume index or stroke work index in the systemic circulation, either between stentless and stented valves or between aortic homografts and Toronto valves, although the cross-clamp time required to insert a stentless valve was 20 minutes longer than that for a stented valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2004

Relation of weights of operatively excised stenotic aortic valves to preoperative transvalvular peak systolic pressure gradients and to calculated aortic valve areas.

OBJECTIVES: The purpose of this study was to correlate the weights of operatively excised stenotic aortic valves to preoperative transvalvular peak systolic gradients and to calculated aortic valve areas. BACKGROUND: No previous publication has correlated the weights of stenotic aortic valves to the transvalvular gradients or to the calculated aortic valve areas. METHODS: We weighed operatively excised stenotic aortic valves in 324 adults who had undergone preoperative left-sided cardiac catheterization. RESULTS: As the weights of the operatively excised stenotic aortic valves increased (from <1 g to >6 g), the average transvalvular peak systolic pressure gradients progressively increased. For any valve weight, in general, the women had higher average transvalvular gradients (p </= 0.005) and lower average valve areas (p </= 0.008) than did the men. Correlation between aortic valve weight and transvalvular gradient improved further when gender was taken into account. CONCLUSIONS: Preoperative transvalvular peak systolic pressure gradients across stenotic aortic valves correlate better with the weights of the operatively excised valves than do the calculated valve areas.

Adult↗
PubMed2000

Aortic valve replacement: is valve size important?

OBJECTIVE: We sought to determine whether aortic prosthesis size adversely influences survival after aortic valve replacement. METHODS: A total of 892 adults receiving a mechanical (n = 346), pericardial (n = 463), or allograft (n = 83) valve for aortic stenosis were observed for up to 20 years (mean, 5.0 +/- 3.9 years) after primary isolated aortic valve replacement. We used multivariable propensity scores to adjust for valve selection factors, multivariable hazard function analyses to identify risk factors for all-cause mortality, and bootstrap resampling to quantify the reliability of the results. RESULTS: Twenty-five percent of patients had indexed internal orifice areas of less than 1.5 cm(2)/m(2) and more than 2 SDs (Z-value) below predicted normal aortic valve size. Mechanical valve orifices were smaller (1.3 +/- 0. 29 cm(2)/m(2), Z = -2.2 +/- 1.16) than pericardial (1.9 +/- 0.36 cm(2)/m(2), Z = -0.40 +/- 1.01) or allograft valves (2.1 +/- 0.50, Z = 0.24 +/- 1.17). The overall survival was 98%, 96%, 86%, 69%, and 49% at 30 days and 1, 5, 10, and 15 years postoperatively. Univariably, survival was weakly and inversely related to manufacturer valve size (P =.16) and internal orifice diameter (P =. 2) but completely unrelated to indexed valve area (P =.6) or Z-value (P =.8). These, and univariable differences among valve types (P =. 004), were accounted for by different prevalences in patient risk factors and not by valve size or type per se. Bootstrap resampling indicated that these findings had a less than 15% chance of being incorrect. CONCLUSIONS: Survival after aortic valve replacement is strongly related to patient risk factors but appears not to be adversely affected by moderate patient-prosthesis mismatch (down to about 4 SDs below normal). Aortic root enlargement to accommodate a large prosthesis may be required in few situations.

Adolescent↗
PubMed2002

The pathology of fresh and cryopreserved homograft heart valves: an analysis of forty explanted homograft valves.

OBJECTIVE: Tissue degeneration reduces the durability of aortic and pulmonary homograft heart valves. Homograft valves can evoke cellular and humoral immune responses that might be detrimental to the valve tissue. Analyzing explanted homograft valves helps in understanding the different factors that eventually lead to tissue degeneration. METHODS: A total of 40 homografts was acquired from patients whose grafts had been explanted because of stenosis (n = 22), insufficiency (n = 8), paravalvular leakage (n = 4), other technical problems (n = 4), noncardiac death (n = 1), and stenosis with endocarditis (n = 1). The period of implantation varied from 14 days to 16 years (median, 4 years). Cryopreserved valves (n = 31) were, in the majority, derived from beating-heart donors, whereas the fresh valves were sterilized with antibiotics and stored at 4 degrees C for an average of 32 days. Four unimplanted cryopreserved valves, 1 native aortic valve, and 1 native pulmonary valve were used as references. Analysis included macroscopy, light microscopy with routine hematoxylin and eosin staining (cellularity and tissue structure), and immunohistochemical studies to allow identification of macrophages (CD68) and T lymphocytes (CD3), endothelial cells, leukocyte adhesion molecules (CD54, CD106, and CD62E), and immunoglobulin (IgG) and complement factor (C3) depositions. In situ hybridization for the Y chromosome was performed in 10 cases, with host-donor sex mismatch, to distinguish between host and donor cells. The outcomes of histology and immunohistochemistry were related to clinical factors, such as implantation time and reason for explantation. RESULTS: In the first year after implantation, a strong reduction in cellularity of the valve tissue was observed, with almost acellular tissues after 1 year. Trilaminar tissue architecture disappeared with the same speed, whereas endothelial cells were almost absent in all explants. Macrophages and T lymphocytes were encountered in 85% and 78% of the leaflets, respectively. Expression of leukocyte adhesion molecules was low in almost all grafts, and IgG and C3 depositions were not increased. Valve tissue cellularity consisted mainly of ingrown host cells when the implantation time exceeded 1 year. CONCLUSIONS: During the first year of implantation, homograft valves rapidly lose their cellular components and normal tissue architecture. A low-grade inflammatory response was observed, but no convincing evidence of immune-mediated injury was found.

Adolescent↗
PubMed2006

Hemolysis, high-intensity transient signals (HITS) and hemodynamic results after aortic valve replacement with the Medtronic Hall Easy-Fit heart valve prosthesis.

BACKGROUND AND AIM OF THE STUDY: Previous studies have shown a correlation between type, orientation and valve size of mechanical heart valve prostheses and the incidence of high-intensity transient signals (HITS). The study aim was to investigate the presence of HITS and hemolysis and the impact of valve size and hemodynamic parameters following aortic valve replacement (AVR) using the new Medtronic Hall Easy-Fit prosthesis. METHODS: A total of 150 patients (120 males, 30 females; mean age 62 +/- 8 years; range: 32-78 years) underwent AVR (n = 94; 63% concomitant procedures) with the Easy-Fit valve in its optimal orientation. Patients were investigated at between three and 36 months after AVR using transcranial Doppler examination of the right and left middle cerebral artery, and the incidence of HITS was determined. For evaluation of hemolysis, serum lactate dehydrogenase (LDH), hemoglobin and bilirubin were measured. These parameters were related to valve size. Transthoracic echocardiography was performed in all patients. RESULTS: Among the patients, 112 (75%) showed no or low HITS (34% none, 41% < 30/h), while only 38 (25%) had elevated HITS (range 31-100/h, 14%; range > 100/h, 11%). Statistical analysis showed a linear association between the HITS count and valve size. A positive correlation between valve size and LDH was observed; hemoglobin and bilirubin showed normal values. CONCLUSION: The valve size-dependent increase in LDH after AVR corresponds with the observation that the presence of HITS increases with valve size. In light of these findings, the surgical approach to implant the largest size Easy-Fit valve possible should be discussed, given the excellent hemodynamic results provided by the valve, even in smaller sizes.

Adult↗