Late results after left-sided cardiac valve replacement in children

Selection of types of cardiac valve substitutes for children remains controversial. Between 1976 and 1984, 166 children, 15 years of age or younger, underwent aortic (N = 53) or mitral valve replacement (N = 90) or both (N = 23). Biological prostheses were used in 84 patients and mechanical prostheses in 71; both a mitral bioprosthesis and an aortic mechanical valve were used in 11 patients. The overall early mortality was 9%. Mean follow-up intervals were 4.1 years for the bioprosthesis group, 3.3 years for the mechanical valve group, and 3.5 years for the group receiving both. The 7 year survival rates (+/- standard error) were 63% +/- 6% in the bioprosthesis group and 70% +/- 7% in the mechanical valve group (p = NS). After aortic valve replacement the 7 year survival rates were 66% +/- 14% (bioprosthesis group) and 77% +/- 9% (mechanical valve group) (p = NS); after mitral valve replacement the rates were 65% +/- 7% (bioprosthesis group) and 54% +/- 17% (mechanical valve group) (p = NS). The incidence of thromboembolic events was 0.6% +/- 0.4% per patient-year in the bioprosthesis group (none after aortic valve replacement, 0.8% +/- 0.6% per patient-year after mitral valve replacement) and 1.4% +/- 0.8% per patient-year in the mechanical valve group (0.7% +/- 0.7% per patient-year after aortic valve replacement, 4.0% +/- 2.8% per patient-year after mitral valve replacement) (p = NS). The linearized rates of reoperation were 10.4% +/- 1.8% per patient-year (bioprosthesis group) and 2.3% +/- 1.0% per patient-year (mechanical valve group) (p less than 0.001). The 7 year probability rates of freedom from all valve-related complications were 43% +/- 6% in the bioprosthesis group and 86% +/- 4% in the mechanical valve group (p less than 0.001). In the aortic position, a mechanical adult-sized prosthesis can always be implanted, and satisfactory long-term results can be anticipated. In the systemic atrioventricular position, the results are less than satisfactory with either type of prosthesis; every effort should be made to preserve the natural valve of the child.     

Tricuspid valve replacement: an analysis of 25 years of experience at a single center

BACKGROUND: Tricuspid valve replacement is seldom used in clinical practice, but the choice between mechanical and biologic prostheses remains controversial. METHODS: Between 1977 and 2002, 97 patients underwent tricuspid valve replacement and were followed at the Montreal Heart Institute Valve Clinic. Patients underwent replacement with bioprostheses (n = 82) and mechanical valves (n = 15). RESULTS: Patients with bioprosthetic tricuspid replacements averaged 53 +/- 13 years of age compared with 48 +/- 11 years in those with tricuspid mechanical valve replacements (p = 0.2). Isolated tricuspid valve replacement was performed in 11 patients (73%) in the mechanical valve group compared with 31 patients (38%. p = 0.01) in the bioprosthetic replacement group. In patients undergoing bioprosthetic tricuspid replacement, 51 (62%) underwent multiple associated valve replacements. The 5-year survival after tricuspid replacement averaged 60% +/- 13% in the mechanical valve group and 56% +/- 6% in the biologic replacement group (p = 0.8). The 5-year freedom rate from tricuspid valve reoperation averaged 91% +/- 9% in patients with mechanical valves and 97% +/- 3% in those with biologic valves (p = 0.2). CONCLUSIONS; Patient survival after tricuspid valve replacement is suboptimal but related to the clinical condition at operation. The use of biologic prostheses for tricuspid valve replacement remains a good option in young patients because of limited life expectancy unrelated to the type of tricuspid prostheses at long-term follow-up.     

Early mechanical failures of the Hancock pericardial xenograft

From August 1981 to July 1984, a total of 97 Hancock pericardial xenografts were implanted in 84 patients, whose ages ranged from 13 to 75 years (mean 55.7 +/- 13). Mitral value replacement was performed in 17, aortic valve replacement in 54, and mitral-aortic valve replacement in 13. Operative survivors were reevaluated from July to September 1985. Cumulative duration of follow-up is 167 patient-years (range 0.5 to 4.1 years), and follow-up is 99% complete. The overall late mortality (at 4 years) is 3.6% +/- 1.4% per patient year, and the actuarial survival rate is 95.4% +/- 3% for aortic valve replacement, 74.7% +/- 16.5% for mitral valve replacement, and 67.1% +/- 20.7% for mitral-aortic valve replacement. One patient sustained a thromboembolic event after mitral valve replacement, but no such complications occurred after aortic or mitral-aortic valve replacement. Actuarial freedom from embolism at 4 years is 100% for aortic and mitral-aortic valve replacement and 93.3% +/- 6.4% for mitral valve replacement. Reoperation for Hancock pericardial xenograft dysfunction was performed in seven patients (five aortic and two mitral-aortic). In the aortic valve replacement group the causes were endocarditis in one, paravalvular leak in one, and primary tissue failure in three; all survived reoperation. The two patients with mitral-aortic valve replacement required reoperation because of primary tissue failure of both Hancock pericardial xenografts, and one died. All values explanted because of primary tissue failure showed commissural tears causing severe prosthetic regurgitation. Calcium deposits were severe in one and mild but unrelated to the cusp rupture in another. Collagen disarray was seen only at the site of the tears, whereas the collagen structure was well preserved in the intact parts of the cusps. Four patients with aortic valve replacement and one with mitral valve replacement show evidence of Hancock pericardial xenograft failure and are awaiting reoperation. The actuarial freedom from primary tissue failure at 4 years is 74.3% +/- 9.8% for aortic and 78.9% +/- 13.2% for mitral Hancock pericardial xenografts. At medium-term follow-up, the Hancock pericardial xenograft has shown poor durability and an extremely high rate of early mechanical failure, especially in the aortic position. These observations suggest the need for a close follow-up of Hancock pericardial xenograft recipients and possibly elective reoperation in asymptomatic patients with clinical evidence of prosthetic failure. These results have led us to discontinue the clinical use of this pericardial xenograft.     

Neurocognitive deficit following aortic valve replacement with biological/mechanical prosthesis.

OBJECTIVE: The aim of this study was to objectively measure neurocognitive deficit following aortic valve replacement with a mechanical or biological prosthesis. MATERIALS AND METHODS: In this prospective, contemporary study we followed 82 consecutive patients undergoing isolated aortic valve replacement with either a mechanical (n=29, mean age=52+/-7 years) or a biological (n=53, mean age=68+/-10 years) valve prosthesis. Neurocognitive function was measured by means of objective P300 auditory evoked potentials (peak latencies, ms) and two standard psychometric tests (Trailmaking Test A, Mini Mental State Examination) before the operation, 7 days and 4 months after the operation, respectively. RESULTS: Since P300 peak latencies increase with age, preoperative P300 measures are lower in patients receiving mechanical valves (360+/-35 ms, mean 52 years) as compared to patients receiving biological valves (381+/-34 ms, 68 years, P=0.0001). Seven days after surgery, P300 peak latencies were prolonged (-worsened) in both groups as compared to preoperative values (mechanical valves: 384+/-36 ms; P=0.0001 and biological valves: 409+/-39 ms; P=0.0001). Although on a different level (-age-related), this development was comparable within both groups (P=0.800). Four months after surgery, P300 peak latencies normalized in the mechanical valve group (372+/-27 ms, P=0.857 versus preoperative), while in contrast in the biological valve group they remained prolonged (417+/-37 ms, P=0.0001). We found no difference within patients receiving different types of biological or mechanical aortic valves. CONCLUSION: Postoperative neurocognitive damage is not reversible in (-elderly) patients with biological aortic valve replacement, while in contrast postoperative neurocognitive damage is reversible in (-younger) patients with mechanical valve replacement. For this contrary development, age seems to be most important, whereas damage related to type of valve prosthesis may be overestimated.     

Pulmonary valve replacement with a mechanical prosthesis. Promising results of 28 procedures in patients with congenital heart disease.

OBJECTIVE: Pulmonary valve replacement is performed increasingly late after correction of Tetralogy of Fallot. Most reports deal with pulmonary allografts as the valvar substitute of choice, although late deterioration and reoperation(s) are the rule. Mechanical valves are scarcely reported and if so only because of complications. Although life-long anticoagulation therapy is indicated for mechanical prostheses, the chance of subsequent re-operations can be expected to be low. We report the results of 28 mechanical valve replacements in the pulmonary position. METHODS: A mechanical valve was implanted in 27 of 79 patients indicated for pulmonary valve replacement. Tetralogy of Fallot was the most common basic lesion. The results and follow-up were reviewed retrospectively, where death and re-operation were primary end points. Routine outpatient follow-up, including trans-thoracic echocardiography, was performed. RESULTS: Twenty-eight pulmonary valve implantations were done in 27 patients. Thirty-day hospital mortality was 1/28 (3.6%), because of a cerebro-vascular accident. One patient died late (2.8 years postoperatively). Median age was 33 years and the median interval between primary repair and insertion of the prosthesis was 26 years. Freedom from re-operation at 1 year was 100%. One valve had to be replaced 14 years after implantation because of malfunction due to ingrowth of endomyocardial fibrosis. No thrombo-embolic events were observed. CONCLUSIONS: Our series do not confirm the bad reputation of mechanical valvar prostheses in the pulmonary position. On the contrary they perform well and result in a much lower re-operation rate than can be expected and in fact is reported after allograft usage. No thrombo-embolic complications were noted. In our experience pulmonary mechanical valve prostheses do well.     

Reoperations for left-sided low-profile mechanical prosthetic obstructions

A series of 2,474 hospital survivors of primary mitral, aortic, and double mitral-aortic valve replacement were observed for a cumulative period of 11.945 years (mean, 4.2 years; range, 0.6-14 years). The linearized incidences of reoperations for thrombotic obstructions were 0.33 +/- 0.08% for mitral valve replacement, 0.36 +/- 0.1% for aortic valve replacement, and 0.42 +/- 0.1% for double valve replacement (p = not significant). Forty-one patients (16 mitral, 12 aortic, and 13 double valve replacements) underwent a total of 44 reoperations with a mean interval of 36 +/- 29 months (range, 0.25-85 months) between operations. Diagnosis was established invasively only in 13 patients (30%). Hospital mortality at reoperation was 18% (8 patients); 28 patients (63%) required emergency surgery. The choice surgical procedures were thrombectomy for clotted aortic prostheses (18 of 24) and valve replacement for obstructed mitral valves (22 of 25; p less than .001). Rethrombosis occurred in 3 patients (1 aortic and 2 double valve replacements). At hospital admission 17 patients (38%) had prothrombin times outside therapeutic ranges (between 20 to 30% of the normal value). The incidence of reoperations for thrombosis in low-profile mechanical prostheses was unaffected by valvar position and number of prostheses implanted. Rethrombosis occurred only in previously cleaned valves, although its occurrence was not significant. The present results indicate that, as experience is gained in the diagnosis and surgical management of this complication, hospital mortality can be reduced significantly (from 37% to 4%).     

Long-term results with triple valve surgery

BACKGROUND: Whether to use biological or mechanical prostheses and whether to repair or replace the tricuspid valve during primary and reoperative triple valve surgery remains controversial. The objective of the present study was to review our experience with primary and reoperative triple valve surgery using CarboMedics (CM) and Carpentier-Edwards (C-E) heart valves. METHODS: All 73 patients undergoing triple valve surgery since 1982 were prospectively followed at the Montreal Heart Institute valve clinic. Aortic valve replacement was performed with CM prostheses (57 patients) and with C-E prostheses (16 patients). Mitral valve replacement was performed with mechanical prostheses (56 patients) and with biological valves (14 patients). Mitral valve repair was done in 3 patients. Tricuspid valve annuloplasty or commissurotomy or both were performed in 66 patients and the tricuspid valve was replaced in 7 patients. Patient survival, complications, and the type of valve procedures were analyzed. RESULTS: Thirty patients averaging 62+/-10 years of age underwent primary triple valve surgery and 43 patients averaging 60+/-10 years of age underwent reoperative triple valve surgery (p = 0.5). Tricuspid repair consisted of annuloplasty with the Bex linear reducer (n = 47), the C-E ring (n = 13), or the De Vega technique (n = 5). Tricuspid valve replacement was done using the C-E pericardial prostheses. The 30-day mortality was 17% and 12% in patients with primary and reoperative surgery, respectively (p = 0.5) and patient survival averaged 80%+/-7%, 75%+/-8%, and 41%+/-15%, and 70%+/-7%, 57%+/-9%, and 50%+/-10%, respectively 1, 5, and 10 years following surgery (p = 0.5). The freedom rate from thromboembolism and from bleeding complications were 87%+/-6% and 95%+/-3% in primary and reoperative patients, respectively, 5 years following surgery. CONCLUSIONS: Triple valve surgery, either as a primary or a reoperative procedure, results in acceptable long-term survival with both mechanical and biological prostheses.     

Bivalvular mechanical mitral-aortic valve replacement in 254 patients: long-term results--a 22-year follow-up

BACKGROUND: We have retrospectively studied 254 patients who underwent a bivalvular mechanical mitral-aortic replacement in the cardiovascular and thoracic surgery unit of Nantes from 1979 to 1989. The follow-up was 22 years (1979 to 2001). The last patient was operated on 12 years before the end of the follow-up. METHODS: All mitral prostheses were St. Jude Medical (SJM) bileaflet valves, and the aortic prostheses were 124 monodisc Bj?rk-Shiley valves, 3 Sorin prostheses, and 127 St. Jude Medical bileaflet prostheses. The mean age was 56.8 +/- 8.5 years with a sex ratio equal to 1. Rheumatism as the etiology predominated with 79.5%. Ninety-seven percent of the patients were followed for a total of 2,779 patient-years and a mean of 11.7 years. RESULTS: Operative mortality was 7.08%. Freedom from overall mortality and valve-related mortality at 22 years were 45.7% +/- 3.6% and 73.1% +/- 3%, respectively. The linearized rates of thromboembolic and hemorrhagic events were 1.07% and 0.9% per patient-year, respectively. Multivariate analysis showed age (p < 0.002), sex (p < 0.01), and degenerative etiology (p = 0.04) as independent factors of late mortality, and age, sex, degenerative disease, and tricuspid pathology were related to valve-related mortality. CONCLUSIONS: This study shows good results after mechanical mitral-aortic replacement in terms of survival rate and quality of life in surviving patients, and outlines the factors influencing long-term results as compared with isolated mitral valve replacement.     

Late results after mitral valve replacement with bileaflet mechanical prosthesis in children: evaluation of prosthesis-patient mismatch

BACKGROUND: Mechanical prosthesis is the choice of valve at the mitral position in children, although re-replacement of prostheses because of prosthesis-patient mismatch is almost inevitable when prostheses were implanted in small children. The methods to predict prosthesis-patient mismatch as a result of patients' somatic growth or pannus formation in children by noninvasive methods have not been well established. METHODS: Thirty-two children underwent mitral valve replacement with 37 bileaflet mechanical prostheses (26 St. Jude Medical prosthetic valves, and 11 CarboMedics prosthetic valves) and were followed up a mean of 6.8 years (maximum 18.3 years) with a complete follow-up rate of 94%. RESULTS: There were no operative deaths and 5 late deaths. Re-replacement of mitral valve because of prosthesis-patient mismatch was required in 5 patients. Freedom from valve-related events and re-replacement of mitral valve at 15 years were 32% +/- 23% and 54% +/- 18%, respectively. Actuarial survival rate was 63% +/- 19% at 15 years. Prosthetic valve orifice area index (manufactured geometric prosthetic valve area divided by patient's body surface area) was well correlated with maximum transprosthesis flow velocity estimated by Doppler echocardiography during follow-up, whereas valve orifice area index had no significant correlation with pulmonary artery wedge pressure assessed by cardiac catheterization. Maximum transprosthesis flow velocity had a significant correlation with pulmonary artery wedge pressure. CONCLUSIONS: Valve orifice area index itself was not a reliable index to predict prosthesis-patient mismatch. Maximum transprosthesis flow velocity was a useful index to predict pulmonary artery wedge. Invasive cardiac catheterization to determine re-replacement of the prosthesis should be considered when maximum transprosthesis flow velocity exceeds 270 cm/s.     

Long-term outcome after biologic versus mechanical aortic valve replacement in 841 patients

OBJECTIVE: The purpose of this study was to optimize selection criteria of biologic versus mechanical valve prostheses for aortic valve replacement. METHODS: Retrospective analysis was performed for 841 patients undergoing isolated, first-time aortic valve replacement with Carpentier-Edwards (n = 429) or St Jude Medical (n = 412) prostheses. RESULTS: Patients with Carpentier-Edwards and St Jude Medical valves had similar characteristics. Ten-year survival was similar in each group (Carpentier-Edwards 54% 3% versus St Jude Medical 50% 6%; P =.4). Independent predictors of worse survival were older age, renal or lung disease, ejection fraction less than 40%, diabetes, and coronary disease. Carpentier-Edwards versus St Jude Medical prostheses did not affect survival (P =.4). Independent predictors of aortic valve reoperation were younger age and Carpentier-Edwards prosthesis. The linearized rates of thromboembolism were similar, but the linearized rate of hemorrhage was lower with Carpentier-Edwards prostheses (P <.01). Perivalvular leak within 6 months of operation was more likely with St Jude Medical than with Carpentier-Edwards prostheses (P =.02). Estimated 10-year survival free from valve-related morbidity was better for the St Jude Medical valve in patients aged less than 65 years and was better for the Carpentier-Edwards valve in patients aged more than 65 years. Patients with renal disease, lung disease (in patients more than age 60 years), ejection fraction less than 40%, or coronary disease had a life expectancy of less than 10 years. CONCLUSIONS: For first-time, isolated aortic valve replacement, mechanical prostheses should be considered in patients under age 65 years with a life expectancy of at least 10 years. Bioprostheses should be considered in patients over age 65 years or with lung disease (in patients over age 60 years), renal disease, coronary disease, ejection fraction less than 40%, or a life expectancy less than 10 years.     

Incidence and risk factors of prosthetic valve endocarditis

To study the incidence and risk factors of prosthetic valve endocarditis (PVE) we followed 99.5% of 912 patients who had valve replacements from 1 January 1981 to 31 December 1985 for 1-6 (mean 3) years. PVE occurred in 27 patients (2.96% or 0.98% per patient-year). The incidence of PVE in the aortic position (3.9%) was significantly higher than in the mitral position (1.5%): chi-square = 6.1, P less than 0.025. PVE developed in 19 of 329 patients with bioprostheses (5.8%), and in 8 of 583 patients with mechanical valves (1.4%): chi-square = 14.48, P less than 0.005). Actuarially at 5-year follow-up, 90.7% +/- 2.16% of the bioprosthetic group and 98.4% +/- 0.56% of the mechanical valve group was free of PVE (P less than 0.001). Antecedent endocarditis increased both the incidence and relative risk of PVE 7-fold compared to patients without antecedent endocarditis (chi-square = 32.0, P less than 0.0001). Bioprosthetic valve replacement in infective endocarditis increased the risk of PVE 12-fold compared to valve replacement by mechanical prostheses. In conclusion: in the order of importance, antecedent endocarditis, bioprostheses and aortic position are risk factors in the development of PVE. Bioprostheses implanted in patients with antecedent endocarditis further enhance the risk of PVE.     

Intravascular hemolysis in patients with new-generation prosthetic heart valves: a prospective study

OBJECTIVE: A prospective clinical study was designed to assess the frequency and severity of intravascular hemolysis in patients with new-generation, normally functioning prosthetic heart valves. METHODS: Hemolysis was evaluated in 172 patients with a mechanical prosthesis (53 CarboMedics and 119 Sorin Bicarbon) and in 106 patients with a bioprosthesis (15 St Jude Medical Toronto, 19 Baxter Perimount, and 72 Medtronic Mosaic) in the aortic position, mitral position, or both. Aortic valve replacement was performed in 206 patients, mitral valve replacement in 59 patients, and double valve replacement in 13 patients. The presence of hemolysis was assessed on the basis of the level of serum lactic dehydrogenase and serum haptoglobin and the presence and amount of reticulocytes and schistocytes in the peripheral blood. Severity of intravascular hemolysis was estimated on the basis of serum lactic dehydrogenase. Clinical, echocardiographic, and hematologic evaluations were performed 1, 6, and 12 months after discharge. RESULTS: None of the 278 patients experienced decompensated anemia, whereas at 12 months, mild subclinical hemolysis was identified in 49 patients, 44 (26%) with a mechanical prosthesis and 5 (5%) with a bioprosthesis (P <.001). At multivariate analysis, independent predictors of the presence of subclinical hemolysis were mitral valve replacement (P <.001), use of a mechanical prosthesis (P =.002), and double valve replacement (P =.02). Frequency of hemolysis in patients with stented aortic bioprostheses was 3%, whereas it was absent in those with stentless valves. Among mechanical valve recipients, double versus single valve replacement (P =.04) and mitral versus aortic valve replacement (P =.05) were correlated with the presence of hemolysis; double valve recipients also showed a more severe degree of hemolysis (P =.03). In patients with a Sorin Bicarbon prosthesis, hemolysis was less frequent (22% vs 34%, P =.09) and severe (P <.001) than in those with a CarboMedics prosthesis. CONCLUSIONS: In normally functioning prosthetic heart valves, subclinical hemolysis is a frequent finding. A low incidence of hemolysis is found in stented biologic prostheses, and it is absent in stentless aortic valves. Modifications of valve design may contribute to minimize the occurrence of hemolysis in mechanical prostheses.     

Long-term comparative analysis of the Bj?rk-Shiley and Hancock valves implanted in 1975

The long-term results in all patients undergoing isolated mitral, aortic, or double mitral-aortic heart valve replacement operated upon in 1975 has been retrospectively analyzed. A total of 153 patients received the standard Bj?rk-Shiley (flat pyrolytic disc) mechanical prostheses and 150 patients received the noncomposite Hancock porcine xenograft. Overall operative mortality was not significantly different between groups. All patients receiving a Bj?rk-Shiley prosthesis, but none in the Hancock group, received long-term anticoagulant therapy. Medium and long-term actuarial survival rates (5 and 10 years postoperatively) were comparable for the two groups (88% for Bj?rk-Shiley and 84% for Hancock [NS] at 5 years; 86% for Bj?rk-Shiley and 80% for Hancock at 10 years [NS]). The incidence of systemic embolism was similar in the two groups (1.6% +/- 0.4% per patient-year for the Bj?rk-Shiley group and 1.3% +/- 0.3% per patient-year for the Hancock group [NS]). Also the incidence of endocarditis was similar (0.6% +/- 0.2% per patient-year for the Bj?rk-Shiley group and 0.8% +/- 0.3% per patient-year for the Hancock group [NS]). In the Hancock group the overall incidence of reoperations was significantly higher than in the Bj?rk-Shiley group (4.2% +/- 0.6% per patient-year versus 0.9% +/- 0.3% per patient-year (p = 0.001). The major cause for reoperation in the Hancock group was primary tissue failure (3% +/- 0.5% per patient-year). In the Bj?rk-Shiley group the major cause of reoperation was valve thrombosis (0.5% +/- 0.2% per patient-year). Therefore, accepting the fact that other bioprostheses may behave differently from the Hancock noncomposite xenograft, we currently restrict our indications for valve replacement with bioprostheses.     

Clinical experience with the Bj?rk-Shiley integral monostrut heart valve prosthesis in the aortic and mitral position

From May 1982 to May 1985, 174 Bj?rk-Shiley integral monostrut (BSIM) heart valve prostheses were implanted in 160 patients. Eighty-eight valves were placed in mitral and 86 in aortic position. There were 92 males and 78 females with a mean age of 54.1 years (140 patients were in NYHA class III or IV (87.5%]. Single valve replacement was performed in 116 (72%) patients, 30 (19%) underwent multiple valve procedures and in 14 (9%) valve replacement was combined with coronary artery bypass surgery. There were no intraoperative deaths. Six patients died within the first month after surgery. One hundred and fifty-two (98.7%) patients were followed for a total of 190 patient years (average 14.8 months per patient). There were 8 late deaths (4.2 per 100 patient-years), 5 of these were valve related. Valve related complications were observed in 9 patients (4.5 per 100 patient-years). The overall incidence of peripheral embolization was 2.6 per 100 patient years. At the time of the follow-up study 136 (94%) patients were in functional class I and II. Fourteen patients with isolated AVR and six with MVR underwent hemodynamic evaluation on an average of 12 and 10 months after surgery. The early results suggest that the BSIM prosthesis represents a promising alternative in heart valve replacement, because there were no mechanical failures, thromboembolic complications are rare and hemodynamic performance is good.     

Current status of cardiac valve prosthesis

Cardiac valve replacement has been clinically applied for the final therapeutic management of valvular heart disease for the last over 20 years. Cardiac valve prostheses are mainly divided into mechanical and biological valves. As mechanical valve, tilting disc valve or bi-leaflet center opening valve made of antithrombogenic and durable pyrolytic carbon are now widely used. As biological valve, porcine aortic valve or bovine pericardial valve treated with glutaraldehyde-tanning for maintenance of cusp durability and pliability are exclusively used at the present time. However, valve related complications such as thrombus formation, embolic event, infection, hemolysis and valve sound in mechanical valve and valve failure and infection in biological valve are unavoidable clinical problems. Therefore, the cardiac valve prostheses should be selected on the basis of patients medical, social and geographical conditions. It is still necessary to develop the ideal prosthesis without the late complications in connection with decision of optimum surgical timing, and technological improvement of materials and structural design.     

Early Results of Valve Replacement with the Björk-Shiley Convexoconcave Prosthesis

The Björk-Shiley convexoconcave prosthetic valve has design characteristics that may result in a lower incidence of thromboembolic complications than the conventional spherical Björk-Shiley prosthesis. We evaluated the results of valve replacement with the convexoconcave prosthesis in 248 patients receiving 301 prosthetic valves between March, 1979, and June, 1981. One hundred thirteen patients had aortic valve replacement (AVR), 73 had mitral valve replacement (MVR), and 62 had multiple valve replacement. Two hundred nine (84%) were in New York Heart Association Class III or IV. The median duration of follow-up was 13 months, and follow-up information was available for 246 (99%) of the patients. The actuarial incidence of freedom from thromboembolism at two years was 98% in the AVR group, 97% in the MVR group, and 87% in the group having multiple valve replacement. There were no documented episodes of valve thrombosis or mechanical failure and no fatal thromboembolic complications. The absence of valve thrombosis is in marked contrast to the results reported with the spherical disc valve. Although longer follow-up is necessary, it appears that the convexoconcave design represents a major improvement in the Björk-Shiley prosthesis.     

Thrombosis of two St. Jude Medical prostheses in one patient after triple valve replacement. Case report and review of the literature

Reports of experience with the St. Jude Medical (SJM) valve state that thrombosis of the prosthesis is a rare complication. In a 57-year-old woman, reoperation was necessary 12 months after triple valve replacement using SJM prostheses because of thrombosis of the valves in the tricuspid and aortic positions. Dysfunction of both mechanical valves was detected clinically by changing heart sounds and the appearance of murmurs. Echocardiography and cinefluoroscopy confirmed at least one fixed leaflet of the tricuspid prosthesis, but abnormalities of the aortic prosthesis could not be detected. At reoperation, the SJM prosthesis in the tricuspid position was almost completely thrombosed and was replaced by an Ionescu-Shiley bioprosthesis. A thrombotic formation at the hinge point of the SJM aortic prosthesis was removed. To our knowledge, this is the first report of a thrombotic complication of two SJM prostheses after triple valve replacement in one patient.     

Extended (31 years) durability of a Starr-Edwards prosthesis in mitral position

A 62-year-old man underwent mitral valve replacement with a Starr-Edwards caged-ball prosthesis in 1974. He was asymptomatic until February 2005 when he underwent a new cardiac evaluation because of increasing dyspnea and peripheral edema. The echocardiogram showed a severe aortic regurgitation and a mitral valve prosthesis well functioning. At reoperation, the mitral prosthesis and the aortic valve were replaced with St. Jude Medical((R)) bileaflet mechanical prostheses. At macroscopic and radiographic inspection the Starr-Edwards was free from signs of structural valve degeneration. This case demonstrates the impressive durability of a Starr-Edwards prosthesis in mitral position.     

Valve-related complications with the Hancock I porcine bioprosthesis. A twelve- to fourteen-year follow-up study

Valve-related morbidity and mortality after heart valve replacement with the Hancock I porcine bioprosthesis has been retrospectively analyzed. From June 1974 through December 1976, 253 Hancock I bioprostheses (150 mitral and 103 aortic) were inserted in 220 selected patients who survived the operation and had follow-up until June 1989 (mean follow-up 13.5 years, with an accumulative follow-up of 2956.4 patient-years). One hundred seventeen patients had mitral valve replacement, 70 had aortic valve replacement, and 33 had combined mitral and aortic valve replacement. There were 27 thromboembolic events. The probability of being free from thromboembolism at 14 years was 81.0% +/- 7.4% for the mitral valve replacement group, 85.4% +/- 6.7% for the aortic group, and 67.1% +/- 18.4% for the mitral-aortic group. Fifteen episodes of prosthetic valve endocarditis occurred. There were 10 instances of nonstructural dysfunction (paravalvular leaks) in seven mitral valves (4.6%) and in three aortic valves (2.9%). One hundred twenty-two bioprostheses in 106 patients resulted in structural deterioration. The probability of freedom from structural deterioration at 14 years was 37.2% +/- 3.9% for the mitral group, 43.9% +/- 7.1% for the aortic group, and 30.1% +/- 8.9% for the mitral-aortic group. The logistic regression analysis between age at the time of operation and bioprosthetic life (structural deterioration-free period) demonstrates a linear regression curve (r = 0.53). There were 56 late deaths (27 patients died at reoperation). The actuarial survival rate (including hospital mortality) at 14 years was 57.2% +/- 5.4% for the entire series, with no statistically significant difference between groups. The probability of remaining free from valve-related morbidity and mortality at 14 years was 16.7% +/- 4.8% for the mitral group, 20.8% +/- 6.2% for the aortic group, and 14.0% +/- 7.0% for the mitral-aortic group. The long-term results of this series show that the clinical performance of the Hancock I porcine valve appears satisfactory during the first 6 years. The behavior of this bioprosthesis at 14 years' follow-up changes drastically, because only a minor group of patients is free from valve-related complications, justifying the restriction of its use for selected patients.     

A retrospective comparative study of aortic valve replacement with St. Jude medical and medtronic-hall prostheses: a 20-year follow-up study

OBJECTIVE: To compare the long-term clinical outcome of patients who underwent aortic valve replacement with St. Jude Medical and Medtronic-Hall mechanical prostheses. DESIGN: From June 1978 to June 1982, 43 Medtronic-Hall and 48 St. Jude Medical mechanical valves were implanted in 90 consecutive patients with aortic valve disease, and their clinical outcome was retrospectively assessed. RESULTS: At 20 years in the St. Jude Medical group and in the Medtronic-Hall group the actuarial rates of overall survival were 50 and 49% (p = NS), of cardiovascular survival 66 and 63% (p = NS), of valve-related survival 95 and 91% (p = NS), of freedom from major valve-related complications 83 and 45% (p = 0.005), from major cerebrovascular events 93 and 71% (p =0.06), from valve thrombosis 97 and 89% (p = NS), from aortic valve reoperation 93 and 88% (p = NS), from major bleeding 96 and 82% (p = 0.04), and from endocarditis 93 and 82% (p = NS), respectively. The linearized rate of overall major aortic valve prosthesis-related complications was 3.47%/year in the Medtronic-Hall valve group and 1.53%/year in the St. Jude Medical valve group (p = 0.003). Multivariate analysis showed that the type of prosthesis was predictive of freedom from valve-related complications (p = 0.01; 2.849; C.I. 95%: 1.246-6.516). CONCLUSION: The aortic St. Jude Medical mechanical valve seems to be associated with a slightly lower rate of long-term valve-related morbidity than the aortic Medtronic-Hall mechanical valve. Because of the small patient population and the retrospective nature of the study, the choice between these two prostheses should not be made only on the basis of these findings. However, these results suggest a reappraisal for further comparative studies with such an extended follow-up.