Anticoagulant therapy in children with prosthetic valves

The purpose of this study was to evaluate the effectiveness and complications of several types of anticoagulant therapy in children with prosthetic valves. During a 7-year period ending April 1985, 130 children aged 1 to 19 years underwent left-sided valve replacement. Operative mortality was 3%, 5%, and 9%, respectively, for aortic, mitral, and aortic and mitral valve replacement. Among the 123 survivors, 32 (26%) had had aortic, 71 (58%) had had mitral, and 20 (16%) had had aortic and mitral valve replacement. Follow-up ranged from 2 months to 8.2 years, a total of 544 patient-years. The survivors were divided into three groups based on anticoagulant treatment: warfarin sodium, aspirin plus dipyridamole, and no anticoagulants. Among the patients who had aortic valve replacement, thromboembolic complications developed in 2.5% (2.5/100 patient-years) of the aspirin plus dipyridamole group and 5% of the group given no anticoagulants. Only the warfarin group (4%) experienced bleeding complications. Among the patients having mitral valve replacement, thromboembolic complications developed in 4% of the warfarin group, 3% of the aspirin plus dipyridamole group, and 11% of the no anticoagulant group. In addition, 2% of patients in the warfarin group experienced severe bleeding. Two fatal cerebrovascular accidents occurred, both in the aspirin plus dipyridamole group. Patients who received a mitral heterograft were not prescribed any anticoagulant medications, and no thromboembolic complications developed. Among patients having double-valve replacement, complications developed in 5% of the warfarin group and 27% of the group given no anticoagulants.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Ten-year follow-up after valve replacement with the St. Jude Medical prosthesis in children

Since 1979, 50 children, 4 months to 15 years of age, have successfully undergone cardiac valve replacement with the St. Jude Medical prosthesis (St. Jude Medical, Inc., St. Paul, Minn.). There were 24 boys and 26 girls. The valve replaced was mitral in 28 children, aortic in 15, mitral and aortic in 1, and mitral and tricuspid in 1. A left-sided tricuspid valve was replaced in 3 children. Anticoagulant therapy was maintained in all children; 40 children were treated with warfarin, whereas 10 children who underwent aortic or mitral valve replacement were on a regimen of aspirin combined with dipyridamole. The follow-up period, comprising 224 patient-years, ranged from 1 to 10 years. There were four valve-related complications: one from thromboembolism, two from valve thrombosis, and the other one from prosthetic valve endocarditis. Actuarial rate free from all valve-related complications at 10 years was 84.7%. There were four late deaths: one from valve thrombosis and the others from non-valve-related complications. Actuarial survival rate at 10 years was 90.8%. All surviving children are in functional class I, and no child so far has needed replacement of a prosthesis because of somatic growth. These results indicate that the St. Jude Medical prosthesis is a cardiac valve substitute of choice for valve replacement in children.     

Considerations in Selection and Management of Patients Undergoing Valve Replacement with Glutaraldehyde-Fixed Porcine Bioprostheses

From November, 1973, through June, 1978, 428 operations in 425 patients were performed for replacement of aortic, mitral, or aortic plus mitral valves, utilizing 277 Hancock and 180 Carpentier-Edwards bioprostheses. Actuarially determined survival at 36 months was similar for all three groups and compared favorably with our experience with the Björk-Shiley prosthesis. Certain patient-related variables influencing late survival were identified by multivariate analysis and included previous operation for congenital heart disease, coronary artery bypass grafting in nonaortic valve replacement, race (black), age at operation, and New York Heart Association Functional Class. A small but definite incidence of thromboembolism occurred in all three groups, again similar to our experience with the Björk-Shiley prosthesis. Multivariate analysis identified four factors influencing risk of thromboembolism: previous cardiac operation, age, double-valve replacement, and rhythm at discharge. Valve degeneration occurred, primarily in children and young adults. Over the medium term, the porcine bioprosthesis compared favorably with mechanical prostheses in terms of survival, function, and thromboembolism. Certain patient-related variables affecting survival may be modified by earlier surgical intervention.     

The Clinical Life History of Explanted Prosthetic Heart Valves

This report analyzes 118 prosthetic heart valves obtained from 97 patients at reoperation (96) or at postmortem examination (22). The number obtained from the mitral, aortic, and tricuspid positions were 78, 32, and 8, respectively. Duration of implant ranged from one day to 12.3 years. Valves showing the least long-term wear were the Starr-Edwards metal strut-silicone ball and the Björk-Shiley. Moderate long-term durability was provided by the Beall and Starr-Edwards cloth-covered composite-seat prostheses while short-term durability was given by Hancock and Carpentier valves. Reoperation for valve-related causes was performed for 46 of 47 Beall valves, which demonstrated stenosis, hemolysis, and incompetence from component wear, 6 of 27 Björk-Shiley prostheses for valve thrombosis or thromboembolism or both, and 11 of 17 porcine prostheses because of calcification (4) or cusp perforation or rupture. Analyses of wear and fatigue of mechanical valves demonstrated that use of ultrahard materials (pyrolyte carbon, titanium, stellite 21) provided superior durability in contrast to polymeric solids or fabrics with poor abrasion and impact characteristics. Further, cloth and disc wear were evident as early as 0.5 year after implant and appeared to be complete by 4 years. Completeness of healing after 24 months was not related to the type of fabric material used or its construction.This study suggests that mechanical valves made from hard materials have long durability when properly implanted and require fastidious prophylaxis against infection and thromboembolism. The findings of early cusp perforation or rupture in the aortic position and leaflet calcification, stiffening, or disruption in the mitral position for porcine prostheses suggest that frequent and careful examinations of patients with these prostheses are required to detect early signs of stenosis or incompetence and that early reoperation is required before catastrophic valve failure necessitates emergency prosthetic valve replacement.     

Clinical and hemodynamic results of cardiac valve replacement with the Monostrut Bj?rk-Shiley prosthesis

Between May 1983 and April 1986, 318 patients underwent cardiac valve replacement with the Monostrut Bj?rk-Shiley prosthesis. There were 136 aortic valve replacements, 128 mitral valve replacements, and 54 multiple replacements. A total of 373 valves were implanted. Associated procedures were done in 79 (25%) of the patients. Hospital (30-day) mortality rate was 5.6% (18 patients): 2.9% (n = 4) after aortic, 7.8% (n = 10) after mitrals and 7.4% (n = 4) after multiple valve replacement. Follow-up was obtained in all 300 operative survivors, for a total of 500 patient-years (mean 18 months). Actuarial survival rate, excluding operative deaths, at 4 years was 94.7% +/- 1.5% (mean +/- standard error of the mean). There were 16 thromboembolic episodes (3.2/100 patient-years). Freedom from all valve-related complications was 87% +/- 2.4% at 3 1/2 years. Neither valve thrombosis nor structural failure has been observed. Eighty percent of the patients are in New York Heart Association functional class I. Forty-two patients (26 with aortic and 16 with mitral valve replacement) underwent cardiac catheterization a mean of 6 1/2 months after the operation. In the aortic position, peak gradients were an average of 6.9 +/- 1.2 mm Hg. Mean systolic gradients were 12.4 +/- 6.3 mm Hg and did not increase with exercise. In the mitral position, end-diastolic gradients were an average of 2.1 +/- 2 mm Hg and mean gradients, 5.9 +/- 2 mm Hg. Discharge coefficient (estimated orifice area/geometric area) was 0.63 +/- 0.2 for the aortic and 0.53 +/- 0.2 for the mitral prostheses. Disc opening was maximal in most patients. These results indicate that the Monostrut prosthesis has a low rate of thromboembolic events, no structural failures or thrombotic obstructions and excellent hemodynamic performance, especially in the small aortic sizes (discharge coefficient for 19 and 21 mm valves, 0.77).     

Comparison of porcine valve xenografts with mechanical prostheses. A 7 1/2 year experience

A total of 479 valve replacements were performed in 469 patients for aortic, mitral, and tricuspid disease. A total of 529 valves were implanted (311 Carpentier-Edwards, 118 Hancock, 94 Bj?rk-Shiley, and six other mechanical valves). Of the 479 operations, 51.1% (245) were carried out in male patients and 48.9% (234) were carried out in female patients. The mean age was 57.6 years; however, 28.6% (137) of the operations were performed in patients over 65 years of age. One hundred five patients (21.9%) had had previous cardiac operations of one type or another. Follow-up was 99.6% and the average length of follow-up was 36.2 months. The overall operative mortality was 5.6%. The operative mortality in the isolated aortic valve replacement group was 2.0% and that in the mitral valve replacement group, 4.4%. There was a 5.9% valve explant rate in the Hancock series; however, no valve explants were required because of valve dysfunction in either the Carpentier-Edwards or the Bj?rk-Shiley groups. The thromboembolic rate in the aortic valve position was 2.4, 1.1, and 2.1 emboli per 100 patient-years in the Hancock, Carpentier-Edwards, and Bj?rk-Shiley groups, respectively. The thromboembolic rate in the mitral valve position was 2.8, 2.2, and 1.0 emboli per 100 patient-years in the Hancock, Carpentier-Edwards, and Bj?rk-Shiley groups, respectively.     

Aspirin anticoagulation in children with mechanical aortic valves

The optimal method of anticoagulation in children with mechanical heart valves is controversial. Between 1975 and 1986, aspirin or aspirin with dipyridamole has been used for anticoagulation in children receiving a mechanical aortic valve at the University of California, San Francisco. Fifty-one patients (ages 1 to 23 years, mean 12.9 years) were treated with aspirin (n = 45) or aspirin with dipyridamole (n = 6) and observed a mean of 36.5 months (range 3 to 100 months). There were four late deaths: two from endocarditis and two from other medical problems, but none related to thrombosis or embolus. Follow-up was accomplished by direct contact with the patient, parent, or referring physician. Two patients (3.9%) were lost to late follow-up. One minor neurologic event occurred perioperatively and resolved spontaneously. There were no postoperative thromboembolic events. Eleven asymptomatic children were recently studied by magnetic resonance imaging or computed axial tomography of the brain and had no evidence of prior silent cerebral thromboembolic defects. There were four patients (5.9%) who had minor hemorrhagic complications: Three patients had nosebleeds and one patient had an upper gastrointestinal hemorrhage. Five patients were changed to warfarin anticoagulation: the patient with upper gastrointestinal hemorrhage and four older patients because of physician preference, all after uncomplicated aspirin therapy. There were no mechanical valve failures, although one patient required reoperation 9 months later for perivalvular leak. All children have remained in normal sinus or paced rhythm during follow-up. These results show that children with mechanical aortic valves in normal sinus rhythm can be safely treated with aspirin (or aspirin with dipyridamole) with little risk of thromboembolic events, valve thrombosis, or valve failure. Hemorrhagic complications resulting from aspirin are minor and easily treated.     

Acute thrombotic obstruction with Bj?rk-Shiley valves: diagnostic and surgical considerations

Eight patients have had thrombotic obstruction of a prosthetic valve since 1971, six mitral valves and two aortic. All eight patients had a Bj?rk-Shiley valve. During the same period 159 Bj?rk-Shiley valves were placed, 85 in the mitral and 74 in the aortic area. This represents a valve thrombotic occlusive incidence of 4.4 percent in our series, 5.9 percent of mitral and 2.7 percent of aortic prostheses. Among the six patients with mitral prostheses only one survived. The two patients with occluded aortic valves survived. The onset of symptoms was very abrupt in most patients and progressed very rapidly. Acute pulmonary edema was observed in five patients. Anticoagulation was considered inadequate in all patients. Aspirin or dipyridamole was being used in seven patients at the time of thrombosis. The data indicate a high frequency of thrombotic occlusion of Bj?rk-Shiley valves in the absence of full anticoagulation with warfarin derivatives and emphasizes the urgent need for surgery once valve thrombosis is suspected.     

Experience with St. Jude Medical valve prosthesis in children. A word of caution regarding right-sided placement

Thirty-six children aged 6 months to 18 years, underwent insertion of 37 St. Jude Medical cardiac prostheses. In 20, the valve was placed in the aortic or mitral position, and in 16 in the pulmonary or tricuspid position. There was one (2.8%) hospital death. All patients received maintenance doses of salicylates and dipyridamole after the operation. Follow-up data are available for all patients for 12 to 24 postoperative months. There was no incidence of valve dysfunction or thromboembolic complication in any of the 20 patients with valves in the systemic (left) side of the circulation, and all manifested improvement in their functional class. In contrast, six (37%) of the 16 patients with valves in the pulmonary (right) side of the circulation developed dysfunction of the prosthesis 1 to 6 months after insertion. Prosthesis failure was associated with fibrous tissue growing into the struts, leading to leaflet immobilization. At 2 years, the actuarial functional life was 100% for mitral and aortic valves and 70% for pulmonary and tricuspid valves. The data illustrate the excellent hemodynamic function of the St. Jude Medical valve in children. The absence of thromboembolic complications warrant continued implantation of the prosthesis in the left side without warfarin anticoagulation therapy, but the high incidence of valve dysfunction in the pulmonary position does not justify its continued use in the right side.     

Late Evaluation of Patients Undergoing Valve Replacement with the Björk-Shiley Prosthesis

This study analyzes 484 patients who survived mitral, aortic, or mitral and aortic valve replacement using the Björk-Shiley prosthesis from January, 1970, through December 31, 1974. Long-term follow-up of 1½ to 6½ years (mean, 3.67 yr) was done on 435 patients (98.2%).Eighty to 85% of the patients have improved noticeably. Thromboembolic problems occurred in 6.9%, representing 1.5 emboli per 1,000 patient-months. Anticoagulant bleeding problems occurred in 6.4% of the patients; late mortality was 15%.Actuarial survival curves showed patients at risk to 6 years having a 79% chance of survival. The same analysis according to preoperative New York Heart Association Functional Classification showed a striking reduction in survival in Class IV patients. The Björk-Shiley prosthesis is a good choice for valve replacement today. Earlier diagnosis and treatment are needed to obtain better long-term survival.     

Fifty-two Consecutive Aortic Valve Replacements Employing Local Deep Hypothermia

From August, 1972, to May, 1974, 52 consecutive aortic valves were replaced with the Björk-Shiley tilting-disc prosthesis. The hospital mortality was zero. Patients ranged in age from 14 to 77 years, and 19 patients had simultaneous correction of associated cardiac lesions. Using techniques of low flow and local deep hypothermia, aortic valve replacement can be accomplished with little risk even in patients with associated coronary arteriosclerosis. Coronary artery perfusion is unnecessary and often hazardous. Follow-up periods vary from one to twenty-one months. Forty-nine patients are alive and substantially improved.     

Clinical and Hemodynamic Evaluation of the 19 mm Björk-Shiley Aortic Valve Prosthesis

Between November, 1973, and March, 1980, 43 patients underwent isolated aortic valve replacement with 19 mm Björk-Shiley prostheses at the Johns Hopkins Hospital. There were 4 male and 39 female patients ranging from 12 to 75 years old (mean, 54.5 years). Average weight was 62 ± 2 kg and average body surface area, 1.64 ± 0.3 m². Five patients died within thirty days of operation; however, since 1975, hospital mortality has been 5.9%. The 38 survivors have been followed up for as long as 85 months (mean, 40 months). There were 4 late deaths, and actuarial survival in patients discharged from the hospital was 81% at five years. All long-term survivors were in New York Heart Association Functional Class I (29 patients) or Class II (5 patients). Preoperative and postoperative echocardiograms in 17 patients demonstrated significant decreases in mean left ventricular wall thickness (12.9 ± 1.8 mm vs 10.3 ± 1.4 mm; p < 0.001) and in left ventricular mass (262 ± 95 gm vs 188 ± 50 gm; p < 0.02).Postoperative cardiac catheterization data were obtained from an additional 24 patients undergoing aortic valve replacement with the 19 mm Björk-Shiley prosthesis at the National Heart Institute. Average peak systolic gradient at rest was 16 mm Hg (range, 0 to 45 mm Hg) and was found to be directly related to body surface area (r = 0.60, p < 0.002). Average effective valve orifice area was 1.06 cm² (range, 0.63 to 2.02 cm²).For patients with small aortic roots, aortic valve replacement with the 19 mm Björk-Shiley valve is a satisfactory and, perhaps, preferable alternative to aortic annuloplasty to accommodate larger sized prostheses.     

Operative results of tricuspid valve replacement with St. Jude Medical prosthesis

Since 1974, 14 patients underwent tricuspid valve replacement (TVR) with prosthetic heart valves. Hardy's operation was undergone in 2 patients with Ebstein's anomaly and mitral valve surgery or multiple valve surgery were undergone in 9 patients with rheumatic valvular disease, concomitantly. Four types of prosthetic heart valves were used in the tricuspid position, i.e. 2 Starr-Edwards prostheses, 1 Hancock xenograft, 1 Bj?rk-Shiley prosthesis and 12 st. Jude Medical prostheses. The operative mortality rate was 14.3% (2/14) and 2 hospital deaths were due to low cardiac output syndrome. Twelve survivors have been followed with a maximum follow-up of 13 years and the mean of 4.7 years. There were 3 late deaths due to congestive heart failure and prosthetic valve endocarditis (PVE) of the aortic Bj?rk-Shiley prosthesis. There was 1 PVE of the tricuspid Starr-Edwards prosthesis and 1 thrombosis of the tricuspid Bj?rk-Shiley prosthesis, but no thrombosis and no other valve-related complications of SJM prostheses in the tricuspid position. The post-operative NYHA function class improved satisfactorily in 9 survivors. Judging from our relatively satisfactory post-operative results in TVR cases using SJM prostheses, SJM prosthesis in the tricuspid position is one of advisable prosthesis to get satisfactory hemodynamic improvement post-operatively.     

Survival and "event-free" analysis of 785 patients with Bj?rk-Shiley spherical-disc valves at 10 to 16 years

Seven hundred eighty-five patients underwent Bj?rk-Shiley spherical-disc valve replacement from 1970 to 1976. There were 268 mitral valve replacements (MVR), 227 aortic valve replacements (AVR), 65 double-valve replacements, and 225 "combined" procedures. A 97.2% follow-up (mean, 12 years) was achieved. With an operative mortality of 4.1% for MVR, 8.4% for AVR, 15.4% for double-valve replacement, and 12.4% for combined procedures, the 12-year survival was most closely related to age at valve replacement: age less than 50 years, 70%; age 50 through 59 years, 52%; and age 60 years or more, 38%. Twenty-four patients (3.1%) (6 who had MVR, 5 who had AVR, 1 who had double-valve replacement, and 12 who had combined procedures) had a thrombosed valve 1 to 134 months postoperatively; this is equal to 0.36 thrombosed valve per 100 patient-years. One hundred eighteen embolic episodes occurred in 94 (13%) of the operative survivors or 1.8 emboli per 100 patient-years. There were major bleeding complications in 0.5% of patients and minor bleeding complications, in 4.0%. Endocarditis appeared in 30 patients (4.2%) or 0.4 episode per 100 patient-years and paravalvular leaks, in 20 patients (2.8%). The event-free survival by age group and valve site at 5, 10, and 12 years is presented. Events included death, thrombosed valves, strokes, bleeding, emboli, paravalvular leaks, and endocarditis. There were 5.3 events per 100 patient-years excluding operative deaths.     

Hemodynamic Evaluation of the Integral Monostrut Björk-Shiley Prosthesis in the Aortic Position

Between May, 1983, and November, 1984, the new integral monostrut Björk-Shiley prosthesis was used for aortic valve replacement in 62 patients. The prosthesis is machined from a solid piece of cobalt alloy and has no welded joints. The traditional U-shaped outlet strut has been replaced by a projecting metal finger that holds the disc in place. The disc opens to 70 degrees and is convexoconcave.Successful transseptal heart catheterization was performed in 23 patients an average of 6 months following operation to evaluate the hemodynamic performance of the prosthesis. The mean peak-to-peak gradient was 7.73 ± 7.49 mm Hg (± standard deviation). In five valves it was 0, and in only three was it higher than 15 mm Hg. Significant peak gradients were directly related to the valve index (valve area/body surface area). Mean systolic gradient at rest was 12.7 ± 6.27 mm Hg and did not increase after exercise. Effective orifice areas were adequate, and the discharge coefficient ranged from 0.77 for the 21-mm prosthesis to 0.48 for the 29-mm prosthesis. Minimal regurgitation, which was washed out on the next systole, was observed with all sizes of the prosthesis. Disc opening was maximal (70 degrees) in all but one of the observed instances.Longer clinical follow-up is required, but the new integral monostrut Björk-Shiley prosthesis, with its important design changes and excellent hemodynamic performance, appears to be a promising aortic valve substitute.     

Results of multiple valve repair. A clinical study of 81 patients

A report is presented of 50 men and 31 women, mean age 50.3 years, who underwent surgery for multivalvular cardiac disease in 1973-1987. NYHA function class was III-IV in 88% of the patients. The most common procedures were aortic + mitral valve replacement (81%), aortic + mitral valve replacement + coronary artery bypass grafting (5%), aortic valve replacement + tricuspid valvuloplasty (5%) and mitral valve replacement + tricuspid valvuloplasty (5%); 95% of the implanted valves were of Bj?rk-Shiley disc type. Nine patients died perioperatively, six due to myocardial infarction and/or low cardiac output. Postoperative bleeding necessitated resternotomy in three cases. Follow-up was complete, with a mean observation time of 4.5 years (a total of 323 patient years). The incidence of thrombotic valve encapsulation was 0.6/100 patient years. Corresponding figures for anticoagulant-related haemorrhage, prosthetic valve endocarditis and paraprosthetic leakage were 0.9, 1.2 and 1.2. In our experience, the rate of late complications after multivalvular reconstruction using Bj?rk-Shiley prosthesis is acceptable if anticoagulant therapy is correctly employed.     

Surgical treatment of annuloaortic estasia: experience in 7 consecutive patients.

Seven patients with annuloaortic ectasia were treated according to the method described by Bentall and De Bono. A Björk-Shiley valve in a composite graft was the prosthesis of choice and was used in all patients except 1, who received a Starr-Edwards valve. Profound topical cooling without selective coronary perfusion was applied in 5 patients for myocardial preservation during aortic occlusion.There was 1 operative death and 1 late death, the latter from cerebral thromboembolism. Five survivors have been followed from 1 year 5 months to 2 years 10 months with an average follow-up of 2 years. Excellent results were obtained in all survivors, their physical capabilities putting them in Class I of the New York Heart Association Functional Classification. Postoperative aortograms showed no signs of kinking or compression of vascular prostheses nor abnormalities of prosthetic valves. A modified technique to secure graft fixation is discussed.     

Mitral valve replacement in the first 5 years of life

Between 1976 and 1986, 19 children aged 1 month to 5 years underwent replacement of the mitral (systemic atrioventricular) valve. Indications for valve replacement included isolated congenital mitral stenosis (n = 2), valve dysfunction associated with a more complex procedure (n = 15), and failed valvuloplasty (n = 2). Seven different valve types were used; nine were mechanical valves and ten were bioprosthetic valves. There were 6 hospital deaths (32%; 70% confidence limits, 20% to 47%). Among the 13 survivors there were 3 late deaths at a mean of 14 months after operation. The late deaths were unrelated to valve malfunction. Thromboembolic events occurred in 2 patients, both with mechanical valves. One minor bleeding complication occurred among 10 patients on a regimen of Coumadin (crystalline warfarin sodium). Five patients, all with bioprostheses, required a second valve replacement. Indications for reoperation included prosthetic valve regurgitation (n = 1) and calcific stenosis (n = 4). No early or late deaths occurred after second valve replacement. Survival was 51% +/- 12% (standard error) at 112 months after valve replacement. Analysis failed to identify age, weight, sex, previous operation, underlying cardiac lesion, or prosthesis size and type as significant risk factors for mortality. Mechanical valves had a lower reoperation rate compared with bioprostheses. These data suggest that although mitral valve replacement within the first 5 years of life is associated with a high operative and late mortality, satisfactory long-term palliation for many patients can be achieved. Mechanical valves are superior to bioprosthetic valves, and offer the best long-term results.     

Comparative analysis of long-term results with porcine-aortic, bovine pericardial and tilting disc valves

The three series with the first-generation valve prostheses were reviewed for long-term clinical evaluation in isolated aortic and mitral valve replacement. Hancock porcine xenograft was implanted in 71 patients from 1977 to 1979, ionescu-Shiley pericardial xenograft (standard model) in 271 patients from 1979 to 1983, and Bjork-Shiley tilting disc valve in 194 from 1978 to 1986. In aortic position, no any significant difference among three valve types could be demonstrated in the actuarial survival and freedom from thromboembolism and valve infection, while the actuarial freedom from valve dysfunction in lonescu-Shiley valve was significantly lower than that in other two valves. Bj?rk-Shiley valve in mitral position showed satisfactory clinical performance in terms of valve-related complications and survival in comparison with two types of bioprosthetic valves. In our conclusion at present time, Bj?rk-Shiley valve is suitable for the first choice of both aortic and mitral valve prostheses. In case of valve replacement with a bioprosthesis, however, porcine aortic valve is a better choice for aortic, and bovine pericardial valve likely for mitral replacement.