More than ten years' follow-up of the Hancock porcine bioprosthesis in Japan.

From February 1975 through October 1981, 256 Hancock porcine bioprostheses (Johnson & Johnson Cardiovascular, King of Prussia, Pa.) (60 aortic, 169 mitral, and 27 pulmonary/tricuspid position) were implanted in 220 patients (104 male and 116 female, aged 9 to 67 years; mean 43.3) at Kyushu University Hospital in Japan. The procedures include 41 aortic valve replacements, 121 mitral valve replacements, 4 pulmonary valve replacements, 6 tricuspid valve replacements, and 48 combined valve replacements (31 aortic plus mitral, 13 mitral plus tricuspid, and 4 aortic plus mitral plus tricuspid). Hospital mortality was 6.4%. Follow-up was 98% during 8 to 14 (mean 10.5) years. Cumulative follow-up was 1836 patient-years and 2078 valve-years. At 10 years the overall actuarial survival rate, including hospital morality, was 70% +/- 3%, and freedom from valve-related mortality with sudden death was 87% +/- 3%. More than half of the current survivors required no anticoagulant therapy. Freedom from thromboembolism or anticoagulant-related hemorrhage (or both) and prosthetic valve endocarditis was common. Freedom from structural valve failure and reoperation declined more than 9 years after replacement of left-sided heart valves but not after replacement of right-sided heart valves. Sixty-seven patients underwent 68 repeat operations, and there were four deaths (5.9%). The rate of freedom from overall valve-related complications at 10 years was 62% +/- 8% for aortic valve replacement, 53% +/- 5% for mitral valve replacement, 80% +/- 13% for pulmonary/tricuspid valve replacement, and 42% +/- 9% for combined valve replacement. There was a significant difference between pulmonary/tricuspid valve replacement and combined valve replacement (p less than 0.05). The Hancock bioprosthesis is suitable for the replacement of valves in the right side of the heart but not for combined valve replacement.     

An eight-year experience with porcine bioprosthetic cardiac valves

A total of 589 porcine bioprostheses were implanted in 509 patients from January, 1976, through December, 1983. Of the valves implanted, 390 were Hancock and 199 were Carpentier-Edwards. A total of 1,633 patient-years was accrued, with a mean follow-up of 38 months per patient. Two hundred eight patients had aortic valve replacement, 209 had mitral valve replacement, and 79 had multiple valve replacements, of which 46 were aortic and mitral replacements. The mortality for isolated aortic valve replacement was 5.8%; for isolated mitral replacement, 8.6%, and for all patients, 10.9%. Late mortality was 3.9% per patient-year. The actuarial survival rate at 5 years was 79% for aortic, 68% for mitral, and 76% for aortic-mitral valve replacement. There were 12 thromboembolic events (0.73% per patient-year). Two episodes occurred in patients with an aortic bioprosthesis, nine in patients with a porcine mitral valve, and one in a patient with mitral and tricuspid bioprosthetic valves. The probability of remaining free of thromboembolism at 5 years was 99% for the group having aortic valve replacement, 93% for those having mitral replacement, and 100% for the group having aortic-mitral valve replacements. Thirteen episodes of endocarditis occurred (0.8% per patient-year). Seven of the 13 patients died as a direct result of endocarditis. The probability of remaining free of prosthetic endocarditis at 5 years was 97% for the aortic valve replacement group, 95% for the mitral group, and 97% for the aortic-mitral group. There were 20 instances of xenograft failure (1.2% per patient-year). The probability of remaining free of valve failure at 5 years was 96% for the aortic valve replacement group, 93% for the mitral group, and 93% for the aortic-mitral replacement group. Primary tissue failure of a prosthesis occurred in seven patients, all with Hancock valves (0.43% per patient-year). As yet there has been no primary tissue failure of the Carpentier-Edwards prosthesis. There also appears to be a lower incidence of thromboembolism (Edwards, 0.3% per patient-year; Hancock, 0.8% per patient-year) and endocarditis (Edwards, 0.6% per patient-year; Hancock, 1.0% per patient-year). The low incidence of complications with the porcine bioprosthetic valve, especially the Carpentier-Edwards, encourages us to recommend its continued use, especially in situations in which anticoagulation is contraindicated.     

Three-year clinical results with the Monostrut Bj?rk-Shiley prosthesis

Between November 1981 and June 1983, 351 patients underwent valve replacement with the Monostrut Bj?rk-Shiley prosthesis. There were 214 aortic valve replacements, 101 mitral valve replacements, and 31 double (aortic and mitral) valve replacements. Four patients had valve implanted in the tricuspid position, and one patient underwent exchange of a valved, extracardiac conduit. Mean age was 61 years (range 2 to 78) and 186 (53%) were male. Concomitant procedures were performed in 52 patients (15%) and 17 (5%) were emergency operations. Early mortality (4.3%) was related to New York Heart Association Functional Class IV, emergency operation, or the presence of a concomitant procedure. Follow-up was 100% and covered 870 patients-years (mean 2.6 years per operative survivor). Postmortem examination was performed in 38 (79%) of the 48 fatalities. Only one patient suffered a sudden, unexplained death. The 3 year survival rate (early mortality excluded) was 88.6% (aortic valve replacement 89.2%, mitral valve replacement 89.3%, and double valve replacement 82.5%). The 3 year freedom from thromboembolism in patients receiving anticoagulants was as follows: aortic valve replacement 97.5%, mitral valve replacement 92.8%, and double valve replacement 100%. There were no instances of valve thrombosis or fatal embolism. In contrast, there were two instances of aortic valve thrombosis among 34 patients having aortic valve replacement without anticoagulation. The 3 year freedom from valve failure (modified Stanford definition) was as follows: aortic valve replacement 96.0%, mitral valve replacement 93.9%, and double valve replacement 89.7%. There were no mechanical failures. In conclusion, the Monostrut Bj?rk-Shiley valve showed a low incidence of complications. There were no mechanical failures, no fatal emboli, and, when anticoagulants were administered, no valve thromboses.     

Late outcome of patients with Braunwald-Cutter mitral valve replacement

Eighty patients who underwent mitral valve replacement (MVR) with Braunwald-Cutter prostheses (54, single valve replacement; 26, multiple valve replacement) between December, 1972, and September, 1975, are discussed. The period of follow-up ranged from 72 to 120 months with a mean of 84.6 months. For the hospital survivors, actuarial survival at ten years was 73 +/- 6.7% for patients with MVR alone and 30 +/- 17.5% for those with multiple valve replacement. The linearized rate of embolic complications in patients with MVR was 3.2% per year and in patients with multiple valve replacement, 1.5% per year. These low rates of embolism allow a favorable comparison of the Braunwald-Cutter valve with other mechanical prostheses. There was no evidence of serious poppet wear or poppet escape after ten years of the valve in the mitral and tricuspid positions. Thus, elective replacement of the Braunwald-Cutter valve from the atrioventricular position because of this potential problem is not considered necessary. In the aortic position, escape of the poppet from the valve has occurred as late as 101 months. The overall morbidity for the group was high. Only 34% of the patients having MVR and 12% of those with multiple valve replacement are expected to be alive and to remain free from any major complication ten years after operation.     

Eight years' experience with the Medtronic-Hall valve prosthesis

During the period January 1981 to September 1986, 444 Medtronic-Hall heart valve prostheses were implanted in 351 patients (mean age, 45 +/- 10 years) mainly for rheumatic valve disease (63.2%). Most of the patients were in New York Heart Association functional class III. Concomitant surgical procedures, mainly conservative tricuspid or mitral procedures or coronary artery bypass grafting, were performed in 101 patients (28.7%). Single-valve replacement was performed in 262 patients (74.6%) (aortic in 117 patients, mitral in 143, and tricuspid in 2), double-valve replacement in 85 (24.2%) (mitral and aortic in 83 and mitral and tricuspid in 2), and triple-valve replacement in 4 (1.1%). Hospital mortality was 6.2%. Follow-up was 97.7% complete. The overall actuarial 8-year survival rate was 77.2%. The linearized incidence of valve-related complications was as follows: thromboembolism, 1.5%/patient-year; reoperation, 1.5%/patient-year; endocarditis, 1.25%/patient-year; hemolysis, 0.52%/patient-year; anticoagulant-related hemorrhage, 0.39%/patient-year; and noninfection-related paraprosthetic leak, 0.33%/patient-year. There were no instances of structural failure. We conclude that after 8 years of follow-up, the Medtronic-Hall valve prosthesis has an excellent clinical performance and a low range of valve-related complications.     

Ten year clinical experience with the CarboMedics heart valve implants

We reviewed the histories of 144 patients who underwent heart valve replacement with the CarboMedics prosthesis from 1990 to 2000. There were 74 males and 70 females, with a mean age of 52 years, including 69 aortic valve replacements, 48 mitral valve replacements, and 27 double (aortic and mitral) valve replacements. The mean duration of follow-up was 6.5 years. Early mortality was 7.6% (11 patients). Late deaths occurred in 14 patients, including cardiac-related late deaths in 9 and valve-related deaths in 3. The survival rate including early deaths was 84.7 +/- 3.2% at 5 years and 78 +/- 4.1% at 10 years. Preoperative New York Heart Association Class IV (p = 0.0001) was found to be a significant predictor of cardiac-related late death. Freedom rate from complications at 10 years were embolism 84.7 +/- 4.2% (linearized rate 1.8% per patient year), valve thrombosis 92.7 +/- 2.7% (linearized rate 0.8% per patient year), bleeding 95.6 +/- 2.6% (linearized rate 0.4% per patient year), reoperation 85.9 +/- 4% (linearized rate 1.5% per patient year), valve endocarditis 98.7 +/- 1.3% (linearized rate 0.1% per patient year), and nonstructural dysfunction 90 +/- 3.5% (linearized rate 1% per patient year). There was no structural deterioration. The early and long-term results with the CarboMedics heart valve implantation were acceptable, but valve thrombosis remains a concern in the present study. Further investigation for optimal anticoagulation therapy is necessary to reduce the incidence of valve thrombosis as well as embolic and bleeding complications.     

Clinical experience with the omnicarbon valve prosthesis]

Between January 1985 and March 1990, isolated valve replacements with the Omnicarbon valve were performed in 90 patients aged 34-72 years. There were 53 aortic valve replacements (AVR) and 37 mitral valve replacements (MVR). The cumulative follow-up was 320 patient-year (py) with a mean follow-up of 3.7 +/- 1.4 years. There were 3 operative and hospital mortalities (3.3%), resulting from retrograde aortic dissection during cardiopulmonary bypass, postoperative renal failure, and rupture of infective pseudoaneurysm in ascending aorta. Seven patients died during the late postoperative period, 4 due to valve-related causes. Two of these patients died of prosthetic valve endocarditis (PVE), while the others died of thromboembolism (including valve thrombosis). The overall actuarial survival rate at 6 years was 86.3% (98.8% for AVR, and 82.1% for MVR). There were 2 thromboembolic events (one mesenteric artery thrombosis, and the other valve thrombosis). The linearized incidence of thromboembolism was 0.63%/py. PVE occurred in 3 patients (0.94%/py). One patient (0.31%/py) was found to have a valve dehiscence due to aortitis syndrome. There were no instances of anticoagulant-related hemorrhage, or valve-related hemolysis. The actuarial rate of freedom from valve-related mortality at 6 years was 93.5% (100% for AVR, and 88.1% for MVR). On the basis of a follow-up period of 6 years, good clinical results and a low incidence of valve-related complications can be demonstrated with Omnicarbon valve.     

Valve replacement in the elderly. Is the mechanical valve a good alternative?

The controversy surrounding the choice of a prosthesis for valve replacement in the elderly patient prompted me to review the performance of mechanical (Medtronic Hall [Medtronic, Inc., Minneapolis, Minn.] and St. Jude Medical [St. Jude Medical, Inc., St. Paul, Minn.]) valves implanted in 213 patients 65 years and older (mean 70.4 years) from 1980 to 1985. There were 63 mitral, 131 aortic, and 19 double (aortic and mitral) valve replacements. Most patients undergoing aortic valve replacement had stenotic lesions, but half of the patients in the mitral valve replacement group had regurgitation with or without stenosis. Early mortality rates for mitral, aortic, and double valve replacement were 4.8%, 6.1%, and 21.1%, respectively (p less than 0.01). The mortality rate for patients 65 to 74 years old was 6.5% and that for those older than 75 years was 9.1%. The cumulative follow-up for the survivors was 850 patient-years. The late mortality rate was 8.1% per patient-year but was valve-related in only 1.3% per patient-year. Noncardiac causes accounted for 43.5% of the late deaths. The late mortality rate was significantly higher in patients who had regurgitant lesions than in those who had stenotic or mixed disease. It was also higher in the older patients (10.3% per patient-year) than in the younger group (7.6% per patient-year; p less than 0.05). Reoperation was required in only six patients (0.7% per patient-year). Thrombotic obstruction of the prosthesis and systemic thromboembolism occurred at linearized rates of 0.6% per patient-year and 2.5% per patient year, respectively, and significant anticoagulant-related hemorrhage at a rate of 0.6% per patient-year. With the exception of late mortality, the incidence of all late complications was similar to that of patients younger than 65 years operated on during the same period. Actuarially, global survival (58% +/- 4%) and freedom from reoperation (95% +/- 2%), from thrombotic obstruction (96% +/- 1%), from thromboembolism (92% +/- 2%), from all valve-related mortality and morbidity (82% +/- 3%), and from valve failure (93% +/- 2%) were also similar to those of the younger patients. Mechanical prostheses perform well in elderly patients. I could not confirm an increase in thromboembolic or hemorrhagic episodes, and the respective mortality and morbidity indexes were similar to those observed in younger patients.     

Aortic valve allografts for mitral valve replacement.

Between May, 1967, and April, 1971, 122 patients underwent mitral valve replacement with fresh aortic valve allografts mounted on rigid support rings. The operative mortality rate was 6.6 percent. Current evaluation was obtained on all patients; the average postoperative follow-up interval for surviving patients is 4.8 years (range, 3.3 to 7.1). Survival rates 1, 2, and 5 years after mitral valve replacement are 89, 86, and 71 percent, respectively. The average functional class of 90 current survivors is 1.6, as compared to 2.9 preoperatively. Thirty-six thromboembolic episodes have occurred in 28 patients, generating a thromboembolism rate of 7 percent per patient year of analysis. Allograft valve dysfunction has occurred in 64 patients, requiring reoperation in 16 and causing death in two. The linearized valve dysfunction rate is 13 percent per patient year. Pathological examination of recovered allograft valves revealed predominantly leaflet fibrosis and calcification, acellular collagenous valve matrix, and infiltration with chronic inflammatory cells. The results of this long-term analysis indicate that mitral valve replacement with fresh aortic allografts provides significant functional improvement and an acceptably low rate of thromboembolism. However, the time-related rate of allograft valve dysfunction is unacceptably high and does not justify further clinical use of this type of bioprosthesis.     

Clinical experience with the Lillehei-Kaster valve prosthesis.

The Lillehei-Kaster valve was used in 215 patients over a 7-year period. The aortic valve was replaced in 81 of them. Hospital mortality was 21% (17 patients). Ten patients were lost to follow-up and long-term mortality was 5% (3 patients). The incidence of thromboembolism was 2.6 per 100 patient-years, and actuarial survival was 96% at 5 and 87% at 7 years. Mitral valve replacement was performed in 108 patients. Hospital mortality was 20% (22 patients), 24 patients were lost to follow-up, and long-term mortality was 13% (11 patients). The combined incidence of thromboembolism was 5.0 per 100 patient-years, and actuarial survival was 81% at 5 years and 75% at 7 years. In both groups, the majority of patients improved clinically. Fifteen patients had double-valve replacement, and 11 had coronary revascularization in addition to valve replacement.     

Failure of Hancock xenograft valve: importance of valve position (4- to 9-year follow-up)

To evaluate long-term durability of Hancock valves, we reviewed our results in 107 hospital survivors (120 valves) who were operated on during 1974 through mid-1979. Mitral valve replacement was done in 63 patients, aortic valve replacement in 20, and mitral valve replacement combined with other procedures in 24. The 7-year survival was 84 +/- 4% (standard error of the mean) for 91 patients and 97 valves. During a follow-up of 590 patient-years, 15 (12 mitral and 3 aortic) of 120 valves at risk (87 mitral, 32 aortic, 1 tricuspid) were removed from 14 patients. Six valves (3 mitral and 3 aortic) were removed because of bacterial endocarditis. One mitral valve was removed because of thromboembolism. Eight mitral valves were removed because of valve structural failure, which occurred at a mean follow-up of 42 months. These valves showed extensive calcification, leaflet perforation, or cusp tear. Structural failure was unrelated to valve size, year of implantation, or valve shelf-life. Structural failure was not seen after aortic valve replacement. Results show that structural failure of the Hancock xenograft valve in the mitral position is related primarily to valve position. After aortic valve replacement, valve failure is predominantly due to endocarditis. Although medium-term (mean, 6-year) durability of this xenograft valve compares satisfactorily with prosthetic valves, its high failure rate in the mitral position indicates the necessity for improvement in valve mounting, design, and preservation.     

Late results after Starr-Edwards valve replacement in children

Selection of types of prosthetic heart valves for children remains controversial. The case histories of 50 children surviving valve replacement with Starr-Edwards prostheses between 1963 and 1978 were reviewed to evaluate the long-term performance of mechanical valves. The 31 boys and 19 girls ranged from 6 months to 18 years in age (mean 10.4 years); 19 patients had had aortic valve replacement, 24 patients had had mitral valve replacement, and one patient had had both. Among the six patients who had had tricuspid valve replacement, four had corrected transposition, so that the tricuspid valve was the systemic atrioventricular valve. Mean (+/- standard deviation) follow-up interval was 7.9 +/- 4.9 years (maximum 17 years). For all patients, the 5 year survival rate was 86% +/- 6%. At 10 years postoperatively, the survival rate (+/- standard error) was 90% +/- 7% after aortic valve replacement and 76% +/- 8% after systemic atrioventricular valve replacement. At follow-up, 39 patients were alive, and 38 were in New York Heart Association Class I or II. Of the 11 deaths, four were valve-related. Seven patients had major (requiring hospitalization) thromboembolic events, and five patients had minor transient neurological symptoms suggesting thromboembolism; 50% of these patients were not taking warfarin (Coumadin) at the time of the thromboembolic event. The incidence of late (greater than 30 days) thromboembolism was 5.3 per 100 patient-years after aortic and 2.0 per 100 patient-years after systemic atrioventricular valve replacement. At 10 years postoperatively, 66% +/- 15% of patients who had had aortic valve replacement and 91% +/- 6% of those who had had systemic atrioventricular valve replacement were free of thromboembolism. The excellent long-term survival, absence of mechanical failure, and relatively low rate of thromboembolism with this prosthesis contrast with our experience with biological valves, in which 41% of children required reoperation in 5 years. Currently, mechanical valves, such as the Starr-Edwards prostheses, are our preferred valves for pediatric patients.     

Cardiac valve replacement with glutaraldehyde preserved aortic allografts

From September 1984 to December 1988, 144 patients underwent cardiac valve replacement using glutaraldehyde preserved stent mounted aortic allografts. The mean age was 21.4 years (54.9% were 15 years old or younger). The mitral valve was replaced in 125 patients, the aortic valve in 7, the pulmonary valve in 3, the tricuspid in 1, the mitral and tricuspid in 1, and the aortic and mitral in 7. Hospital mortality was 2.8% (4 patients). Total follow-up was 396.3 patient-years and the mean follow-up was 2.8 years per patient. The 5-year actuarial survival was 73.8% +/- 11.9%. The 4-year actuarial survival for patients aged 15 or younger was 81.4% +/- 7.1%. The overall mortality was 2.8% +/- 0.8%/per patient-year. The incidence of valve-related complications was 4.8% +/- 1.1%/per patient-year, and the calcification rate was 3.0% +/- 0.9%/per patient-year and was the main complication reported in 12 patients, all under the age of 15 years. It occurred 14-47 months after implantation (mean 32.7 months). Five-year actuarial freedom from valve dysfunction due to calcification was 82.6% +/- 5.0% and for patients aged 15 or younger was 69.9% +/- 8.8%. The incidence of reoperation was 3.3% +/- 0.9%/per patient-year. These initial results demonstrate a 5-year actuarial freedom from primary valve failure due to fibrocalcification superior to the results obtained with xenobioprostheses in the paediatric age group.     

The Hancock II porcine bioprosthesis. A preliminary report

From May 1983 to July 1987 a total of 153 Hancock II porcine bioprostheses have been implanted in 130 patients with a mean age of 59 +/- 8 years (range 29 to 76 years). Mitral valve replacement was performed in 72 patients, aortic valve replacement in 35, and mitral-aortic valve replacement in 23. Cumulative follow-up of 121 survivors is 223 patient-years and 100% complete (range 0.4 to 4.5 years). The actuarial survival rate at 4 years is 88% +/- 8% for mitral, 86% +/- 7.8% for aortic, and 84% +/- 8% for mitral-aortic valve replacement. Minor thomboembolism occurred in two patients (0.9% +/- 0.6%/pt-yr) with an actuarial freedom from emboli at 4 years of 100% for mitral, 96% +/- 3.7% for aortic, and 91% +/- 8.6% for mitral-aortic valve replacement. Anticoagulant-related hemorrhage occurred in 10 patients (4.4% +/- 1.4%/pt-yr) with an actuarial freedom at 4 years of 90% +/- 4.8% for mitral, 89% +/- 5.8% for aortic, and 84% +/- 10.6% for mitral-aortic valve replacement. Failure of the porcine bioprosthesis was observed in three patients with an actuarial freedom at 4 years of 96% +/- 3.6% for aortic, 91% +/- 8% for mitral, and 91% +/- 8.6% for mitral-aortic valve replacement. Actuarial freedom from all porcine bioprosthesis-related complications at 4 years is 85.7% +/- 6.6% for aortic, 79% +/- 9% for mitral, and 70% +/- 13% for mitral-aortic valve replacement. No instances of primary tissue failure occurred.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Heart valve replacement in children

Twenty children with heart valve disease were operated upon and underwent heart valve replacement between 1965 and 1968. Thirteen were girls and seven boys. At the time of operation their ages ranged from 3 to 16 years. All the patients were in classes III or IV prior to operation. Three children suffered from congenital valvular lesions and 17 from rheumatic lesions. In each patient left and/or right heart catheterization and angiographic studies were performed. Six patients underwent aortic valve replacement, 11 mitral, 1 tricuspid, and 2 double valve replacement. Mitral annuloplasty was performed in addition to aortic valve replacement in two patients, and tricuspid annuloplasty in addition to mitral valve replacement in another patient. In 19 patients a prosthetic valve was used and in one an aortic heterograft (pig). Two patients died in the early postoperative period (10%), and two later, two and nine months after surgery (10%). Postoperative thromboembolism occurred in four patients (20%). All have completely recovered. All the surviving 16 patients have been followed for a period of one to four and a half years and all showed significant clinical improvement; all children of school age have returned to school and/or other normal actitivies. The overall result has been encouraging and might justify a more aggressive approach in the management of valvular diseases in this specific group of patients.     

Long-term survival after single aortic or mitral valve replacement with the present model of Smeloff-Cutter valves

Two hundred fourteen survivors of single aortic (AVR) or mitral valve replacement (MVR) were evaluated. The present model of the Smeloff-Cutter prosthesis was used in these patients, and the series was started in September, 1966, following the last structural change in the valve. Clinical follow-up ended in September, 1976. Bleeding, thromboembolism, and peristent left ventricular dysfunction were the major complications. Thromboembolism occurred at a rate of 0.13 percent per month of patient follow-up. Late deaths occurred in 19.2 percent of patients, half of these within the first year. Acturarial data indicated a 5 year survival rate of approximately 75 percent after both mitral and aortic replacements. Bleeding and thromboembolism were more frequent causes of death after mitral replacement. Myocardial function was of greatest importance in long-term survival after replacement of either valve. Variations in warfarin dosage significantly affected both bleeding and thromboembolic complications.     

Mitral valve replacement in patients younger than 6 years of age.

We present our experience in mitral valve replacement (including left-sided tricuspid valve in corrected transposition) in patients younger than 6 years of age. The long term results were examined with special focus on re-replacement of the valve. Between 1974 and 1995, we performed mitral valve replacement in 14 patients younger than 6 years of age, with no operative mortality. There were 3 late deaths, caused by endocarditis, valve thrombosis, and congestive heart failure, respectively. The five-year-survival rate after primary replacement was 85%, and the ten-year-survival rate was 75%, using Kaplan-Meier analysis. Ten patients (11 occasions) required repeated mitral valve replacements at 2 months to 17 years after the original replacement. The indication for the second or third mitral valve replacement was paravalvular leakage (2 patients), valve thrombosis (1 patient), degeneration in the porcine prosthesis (3 patients), and patient outgrowth of the original small prosthesis (5 patients). Again there was no operative mortality. One patient who suffered from multiple occasions of valve thrombosis died at two years after the second replacement. All patients who had outgrown the prosthetic valve received larger prosthesis at the second replacement than at the primary replacement. The actuarial percentage of freedom from valve-related events at 3 years, 5 years, and at 10 years, was 50%, 37%, and 8%, respectively. CONCLUSIONS: Mitral valve replacement in patients younger than 6 years of age can be performed relatively safely, but meticulous follow-up and appropriate decision making for re-replacement is mandatory for the long-term survival of these patients.     

Mitral valve replacement in patients younger than 6 years of age

We present our experience in mitral valve replacement (including left-sided tricuspid valve in corrected transposition) in patients younger than 6 years of age. The long term results were examined with special focus on re-replacement of the valve. Between 1974 and 1995, we performed mitral valve replacement in 14 patients younger than 6 years of age, with no operative mortality. There were 3 late deaths, caused by endocarditis, valve thrombosis, and congestive heart failure, respectively. The five-year-survival rate after primary replacement was 85%, and the ten-year-survival rate was 75%, using Kaplan-Meier analysis. Ten patients (11 occasions) required repeated mitral valve replacements at 2 months to 17 years after the original replacement. The indication for the second or third mitral valve replacement was paravalvular leakage (2 patients), valve thrombosis (1 patient), degeneration in the porcine prosthesis (3 patients), and patient outgrowth of the original small prosthesis (5 patients). Again there was no operative mortality. One patient who suffered from multiple occasions of valve thrombosis died at two years after the second replacement. All patients who had outgrown the prosthetic valve received larger prosthesis at the second replacement than at the primary replacement. The actuarial percentage of freedom from valve-related events at 3 years, 5 years, and at 10 years, was 50%, 37%, and 8%, respectively. Conclusions: Mitral valve replacement in patients younger than 6 years of age can be performed relatively safely, but meticulous follow-up and appropriate decision making for re-replacement is mandatory for the long-term survival of these patients.     

Ten years' experience with the Bj?rk-Shiley tilting disc valve.

More than 10 years of clinical experience with 1,800 consecutive valve replacements with the Bj?rk-Shiley tilting disc valve were focused on improving its durability, flow dynamics, thromboresistance, and in vivo functional control. Although the original Delrin disc functions excellently after 10 years in the human circulation, the durability of the prosthetic valve was further prolonged by the introduction of pyrolytic carbon as disc material. The opening mechanism was also reinforced by integrating the bearing struts with the valve ring. No other presently available heart valve prosthesis shows such a low resistance to flow for a given tissue diameter. The disc was equipped with a ring-shaped radiopaque marker that permitted noninvasive functional control. The 5 year survival rates were 82% after aortic, 66% after mitral, and 66% after mitral and aortic valve replacements, including the operative mortality rates. The incidence of systemic emboli was 0.7% per year after aortic, 4.2% per year after mitral, and 2.2% per year after mitral and aortic valve replacements with anticoagulation treatment. The incidence of obstruction by thrombosis was 0.3% per year for aortic, 1.3% per year for mitral, and 2.3% per year tricuspid prostheses. The new convex-concave model decreases the stagnation zone behind the disc, decreases emboli from 4.2% to 1.2% per year after mitral valve replacement, and has a lower gradient.