Ten years experience with the St. Jude Medical valve prosthesis for mitral valve replacement

During the 10-year period between 1980 and December 1989, isolated mitral valve replacement (MVR) with the St. Jude Medical (SJM) valve prosthesis was performed on 404 patients at our hospital, and a long-term postoperative follow-up was conducted. There were 161 males and 243 females ranged in age from 1 year to 73 years. Early operative mortality was 5.2%. Follow-up period for 383 patients who discharged from the hospital was 1970.7 patient-years. Twenty of these patients died during the follow-up period, and a late mortality rate was 5.2%. During 10 years, thromboembolic event occurred in 8 patients. Four patients had anticoagulant-related bleeding, 4 had paravalvular leak, and 5 underwent re-operations. There was neither structural valve failure nor prosthetic valve endocarditis. Therefore, the actuarial survival rate and the valve-related death-free rate at 10 years were 83.2%, and 96.8%. Of the patients who survived, New York Heart Association class improved significantly (93% in classes II and III preoperatively and 71% in class I postoperatively). Linearized rates for thromboembolism, anticoagulant-related bleeding, and hemolysis were 0.41%, 0.20% and 0.36%/100 patient-years, respectively. The actuarial estimate of incidence free from all complications was 92.0% at 10 years. On the basis of this 10 years' experience, we believe that the SJM valve prosthesis is an excellent mechanical prosthesis for mitral valve replacement, in terms of hemodynamic performance and low thrombogenicity in patients receiving anticoagulants.     

Intermittent opening of a mechanical mitral valve prosthesis due to pannus formation; report of a case

A 76-year-old woman with a history of severe mitral valve stenosis had undergone mitral valve replacement with a 27 mm St. Jude Medical (SJM) valve in 1991. Follow-up transthoracic echocardiography revealed an increase in the pressure gradient across the mitral prosthesis 16 years after the surgery. Prosthetic valve dysfunction was suspected, but transesophageal echocardiography and cineradiography failed to show mechanical valve dysfunction. Two years later, she presented with dyspnea on exertion and leg edema. Cineradiography revealed intermittent restriction of the opening of the mechanical valve leaflet approximately every 10 beats. Thus, we diagnosed intermittent prosthetic valve dysfunction and performed a reoperation. On inspection of the prosthesis, we observed semicircular pannus formation around the posterior leaflet in the ventricular side. It was considered that the pannus tissue had interfered with 1 leaflet opening of the mitral valve prosthesis, resulting in intermittent valve dysfunction. We replaced the prosthesis with a new 25 mm SJM valve. The patient was discharged after confirmation of normal prosthetic function.     

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.     

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.     

Case-matched comparison of mitral valve replacement and repair

Carpentier's techniques of prosthetic ring mitral valve repair for mitral regurgitation offer the potential for immediate and long-term improvement in valve function without the necessity of replacing the native valve with a prosthesis. A consecutive, case-matched series of 65 patients with prosthetic ring mitral valve repair was compared with 65 patients undergoing mitral valve replacement for mitral regurgitation. The aortic cross-clamp time was 57 +/- 33 minutes in the repair operations and 41 +/- 25 minutes in the replacement operations (p = 0.003). The cardiopulmonary bypass time was 154 +/- 44 minutes in the repair operations and 113 +/- 41 minutes in the replacement operations (p = 0.0001). There were no myocardial infarctions in the hospital in either group. Hospital death was noted in 1.5% of repairs and 4.6% of replacements (p = not significant). Survival at 4 years was 0.84 for repairs and 0.82 for replacements (p = not significant). Freedom from reoperation to replace the mitral valve at 4 years was 62 of 65 patients in the repair group and 64 of 65 patients in the replacement group (p = not significant). In-hospital and midterm results in a closely matched population show that mitral valve repair yields results comparable with those of replacement despite a more difficult procedure. The benefits of maintaining the native valve with chordal and papillary muscle structure intact and avoidance of prosthetic valve implantation may then become apparent with longer follow-up.     

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.     

Heart valve replacement with the Sorin tilting-disc prosthesis. A 10-year experience.

From 1978 to 1988, 697 patients with a mean age of 48 +/- 11 years (range 5 to 75 years) received a Sorin tilting-disc prosthesis; 358 had had aortic valve replacement, 247 mitral valve replacement, and 92 mitral and aortic valve replacement. Operative mortality rates were 7.8%, 11.3%, and 10.8%, respectively, in the three groups. Cumulative duration of follow-up is 1650 patient-years for aortic valve replacement (maximum follow-up 11.4 years), 963 patient-years for mitral valve replacement (maximum follow-up 9.9 years) and 328 patient-years for mitral and aortic valve replacement (maximum follow-up 9.4 years). Actuarial survival at 9 years is 72% +/- 4% after mitral valve replacement, 70% +/- 3% after aortic valve replacement, and 50% +/- 12% after mitral and aortic valve replacement, and actuarial freedom from valve-related deaths is 97% +/- 2% after mitral valve replacement, 92% +/- 2% after aortic valve replacement, and 62% +/- 15% after mitral and aortic valve replacement. Thromboembolic events occurred in 21 patients with aortic valve replacement (1.3% +/- 0.2%/pt-yr), in 12 with mitral valve replacement (1.2% +/- 0.3% pt-yr), and in seven with mitral and aortic valve replacement (2.1% +/- 0.8%), with one case of prosthetic thrombosis in each group; actuarial freedom from thromboembolism at 9 years is 92% +/- 3% after mitral valve replacement, 91% +/- 3% after aortic valve replacement, and 74% +/- 16% after mitral and aortic valve replacement. Anticoagulant-related hemorrhage was observed in 15 patients after aortic valve replacement (0.9% +/- 0.2%/pt-yr), in 9 after mitral valve replacement (0.9% +/- 0.3%/pt-yr), and in 6 with mitral and aortic valve replacement (0.9% +/- 0.5%/pt-yr); actuarial freedom from this complication at 9 years is 94% +/- 2% after aortic valve replacement, 91% +/- 4% after mitral valve replacement, and 68% +/- 16% after mitral and aortic valve replacement. Actuarial freedom from reoperation at 9 years is 97% +/- 2% after mitral and aortic valve replacement, 92% +/- 4% after mitral valve replacement, and 89% +/- 3% after aortic valve replacement, with no cases of mechanical fracture. The Sorin valve has shown a satisfactory long-term overall performance, comparable with other mechanical prostheses, and an excellent durability that renders it a reliable heart valve substitute for the mitral and aortic positions.     

Tricuspid valve replacement with the St. Jude Medical valve

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

Long-term results of mitral valve replacement using glutaraldehyde-treated porcine bioprostheses--comparison of the Hancock and the Liotta valves

Long-term results of mitral valve replacement using glutaraldehyde-treated porcine bioprostheses were evaluated. The subjects were 77 patients with the Hancock valve (Hancock group) and 60 with the Liotta valve (Liotta group) who survived operation. The maximum follow-up was 14 years and 8 years, and the cumulative follow-up was 631 patient-year (p-y) and 301 p-y in the Hancock and Liotta groups. The actuarial survival rate at 8 years was 80.1 +/- 4.6% for the Hancock group and 88.1 +/- 4.2% for the Liotta group, and there was no significant difference in survival rate between the both groups. The actuarial survival rate at 14 years was 74.3 +/- 5.9% for the Hancock group. The valve-related complications in the Hancock and the Liotta groups were as follow; thromboembolism 1.9%/p-y vs 1.3%/p-y, bleeding 0 vs 0.7%/p-y, perivalvular leak 0.3% vs 0, infection 0.3%/p-y vs 0.7%/p-y, primary tissue failure (PTF) 3.3%/p-y and all valve-related complications 5.9%/p-y vs 6.0%/p-y. There was no significant difference in valve-related complications between the both groups. However, the actuarial event free rate of PTF was significantly lower in the Liotta group than the Hancock group between 4 and 7 years after operation (100% vs 88.8 +/- 4.3% in the 4th year p less than 0.01, 87.7 +/- 4.4% vs 73.5 +/- 8.0% in the 7th year, p less than 0.05). Although the both anti-thrombogenicity and anti-inflammation were acceptable in the porcine bioprostheses, this prosthesis is now used only in the selected patients because of the limited long term durability of this valve.     

A case of thrombosed St. Jude Medical valve 16 years after initial mitral valve replacement]

We report successful surgery for a thrombosed St. Jude Medical (SJM) valve 16 years after the initial mitral valve replacement even under conditions of satisfactory anticoagulation therapy. A 61-year-old-female had intermittent claudication and was admitted to our hospital for examination. The prosthetic valve sounds were normal to auscultation and the left ankle-pressure index was decreased to 0.6. Transthoracic echocardiography revealed no mitral regurgitation and a mean mitral valve gradient of 6-7 mmHg. Furthermore, transesophageal echocardiography revealed that one of the leaflets of the prosthetic valve was entirely immobilized at the closing position and a mobile soft tissue mass, 5 mm in diameter, was detected at the atrial side of the obstructed leaflet. Although 96,0000 IU of urokinase was administered intravenously for a week, we could not confirm any change in leaflet mobility. At the time of surgery, the posterior leaflet of the SJM valve, which was implanted at an anatomical orientation, was obstructed at the closing position with old and fresh thrombi. We decided upon replacement with a CarboMedics 29 M prosthetic valve. Postoperative medication consisted of warfarin plus low-dose aspirin. Generally, valve thrombosis occurs within 5 years after valve replacement. However, valve thrombosis is possible even in a reliable SJM valve and as long as 16 years after replacement. Therefore, the implantation of an SJM valve at an anti-anatomical orientation might lower the incidence of valve thrombosis in addition to life-long anticoagulation therapy.     

Prospective randomized study of St Jude Medical versus Bj?rk-Shiley or Starr-Edwards 6120 valve prostheses in the mitral position. Three hundred and fifty-seven patients operated on from 1979 to December 1983

During a 5 year period (January 1979-December 1983) 357 patients were submitted to mitral valve replacement. These were performed by the same surgeon and were randomized in 2 groups: Group A consisted of 179 patients who received a St Jude Medical (SJM) prosthesis in the mitral position. Group B comprised 178 patients with a Bj?rk-Shiley valve (BSM) initially (113 patients from 1979 to December 1981 matched with 111 SJM) and later a Starr-Edwards 6120 valve prosthesis (65 patients matched with 63 SJM). Analysis of 21 preoperative clinical, hemodynamic data and operative variables showed the groups to be well randomized. All patients were anticoagulated postoperatively. A follow-up study was performed each year postop: at the end of 1986 there was a 35 to 95 months follow-up with a mean of 64.7 months (1596 patient years follow-up). Fifteen patients were lost to follow-up. There were 8.4% deaths related to the prosthesis in group A and 20.2% in group B (p less than 0.001). The difference was due mainly to deaths from thromboembolic complications and sudden deaths. The rate of peripheral arterial embolic complications was 2.3% in group A and 4.3% in group B per patient year (NS). The difference between the 2 groups is significant for all thromboembolic events including sudden deaths: 3.1% in group A and 7.9% per patient year in group B (p less than 0.001). There were no statistical differences in the rates of endocarditis per patient year (0.3% in group A, 0.9% in group B), reoperation (0.75% in group A, 0.89% in group B), or anticoagulant related hemorrhage (1.6% in group A, 2.4% in group B). Actuarial survival rate, including all postoperative deaths, is significantly different (p less than 0.05) at 5 years, 87.6% +/- 4.5 (group A) versus 77.4% +/- 6 (group B) and at 7 years follow-up, 83.4% +/- 6.5 (group A) versus 73.2% +/- 7.2 (group B). The probability of freedom from death and complications related to the prosthesis is significantly different (p less than 0.001) at 5 years postoperatively: 79% +/- 6.5 for group A versus 54% +/- 7.5 for group B and at 7 years: 72% +/- 7.5 (group A) versus 46% +/- 8.5 (group B). Comparison of subgroups, 113 BSM versus 111 SJM (1979-81) and 65 SE 6120 versus 63 SJM (1982-83) showed similar significant differences in the results: however there were more early deaths, valve thrombosis, valve dysfunctions and sudden late deaths in the BSM group and more peripheral arterial emboli in the SE 6120 group.(ABSTRACT TRUNCATED AT 400 WORDS)     

Five-year clinical evaluation of the St. Jude Medical valve prosthesis in 136 patients

One hundred and thirty-six patients (June 1979, through May 1984) underwent mitral, aortic or double valve replacement and apico-aortic bypass with the St. Jude Medical (SJM) prosthesis, at Ryukyu University Hospital, Okinawa. Operative mortality for the entire group was 4.4 per cent. Late mortality from 1979-1984 was 6.1 per cent. There were no deaths related to mechanical failure. Warfarin anticoagulation was recommended for all patients. The incidence of thromboembolism was 0.76/100 patient years. Post operative catheterization studies in 21 patients one year after operation showed a satisfactory recovery of cardiac function. The SJM valve seems to be the satisfactory artificial valve in present use.     

Intermediate results of isolated mitral valve replacement with a Biocor porcine valve

BACKGROUND: We analyzed the intermediate experience, survival, and prosthetic complications of patients who received the Biocor valve, a new-generation porcine valve, in the mitral position. METHODS: At the University of Padua, between May 1992 and January 2004, 154 consecutive patients (102 female and 52 male patients; mean age, 72.3 +/- 6 years; age range, 37-86 years) received 158 mitral Biocor prostheses (Biocor Industria e Pesguisa Ltda, Belo Horizonte, Brazil). Thirty-five percent of the patients had previous mitral operations, 24% had coronary artery bypass grafting, and 34.6% had other procedures. Median preoperative New York Heart Association class was III. Echocardiography was performed in 75% of the long-term survivors. Follow-up included 609.4 patient-years and was 100% complete, with a median time of 4 patient-years (range, 0.02-11.3 years). At 8 years, 20 (14%) of 142 operative survivors were still at risk. RESULTS: Early mortality was 13.6%. According to univariate analysis, New York Heart Association class III to IV, ejection fraction of less than 40%, urgency, male sex, and coronary artery bypass grafting were significant perioperative risk factors. Eight- and 10-year actuarial survival was 51.1% +/- 5.6% (40 deaths). Eight-year actuarial freedom from valve-related death, thromboembolism, anticoagulant-related hemorrhage, endocarditis, paravalvular leak, and valve-related complications were 85.2% +/- 5%, 85.7% +/- 4.4%, 92.6% +/- 3.7%, 94.1% +/- 3%, 91.8% +/- 3%, and 70.2% +/- 5.7%, respectively. Freedom from structural valve deterioration was 100%. Actual freedom from reoperation was 93.2% +/- 2.2%. By Doppler echocardiography, the peak and mean transprosthetic gradients were 15 +/- 5 mm Hg and 6.3 +/- 3 mm Hg, respectively (mean follow-up, 4.2 +/- 2.7 years). CONCLUSION: At intermediate follow-up, the Biocor prosthesis in the mitral position showed excellent results in terms of valve durability when compared with other second-generation tissue valves.     

Left ventricular rupture following mitral valve replacement due to oversize prosthesis

Left ventricular rupture following mitral valve replacement is one of the most serious complications. We report our experience in successful treatment of type III left ventricular rupture following mitral valve replacement probably due to an oversize prosthesis. A 67-year-old woman, with the history of percutaneous transluminal mitral commissurotomy 11 years previously, underwent mitral valve replacement for mitral restenosis with a 27 mm CarboMedics mechanical bileaflet valve (Sulzer CarboMedics Inc., Austin, TX, U.S.A.). There were some difficulties in placing the entire prosthesis into the annulus at the posterior because of the oversize prosthesis. After the complete placement of the prosthesis, bulge of the left ventricular muscle was evident around the left lateral region. Following the cessation of cardio-pulmonary bypass, type III left ventricular rupture, half a circular rip between the papillary muscles and posterior mitral annulus, occurred. The rip was suture-closed and a 23 mm CarboMedics valve was placed. Postoperative ultrasonic cardiography showed no prosthetic stenosis, periprosthetic leak, left ventricular pseudoaneurysm, nor left ventricular asynergy. Under cardioplegic arrest, we should not select the oversize prosthesis to prevent left ventricular rupture.     

Five-year clinical evalution of the St. Jude medical valve prosthesis in 136 patients

One hundred and thirty-six patients (June 1979, through May 1984) underwent mitral, aortic or double valve replacement and apico-aortic bypass with the St. Jude Medical (SJM) prosthesis, at Ryukyu University Hospital, Okinawa. Operative mortality for the entire group was 4.4 per cent. Late mortality from 1979–1984 was 6.1 per cent. There were no deaths related to mechanical failure. Warfarin anticoagulation was recommended for all patients. The incidence of thromboembolism was 0.76/100 patient years. Post operative catheterization studies in 21 patients one year after operation showed a satisfactory recovery of cardiac function. The SJM valve seems to be the satisfactory artificial valve in present use.     

Comparative analysis of Hancock and St. Jude Medical valve after mitral valve replacement]

Long term results were compared in 81 operative survivors with MVR using Hancock valve (Hancock group) and 83 using St. Jude Medical valve (SJM group). The cumulative follow-up was 709.0 patients-year (p-y) and 175.2 p-y in the Hancock and SJM groups. Twenty-four percent of the patients in the Hancock group was permanently anticoagulated, while 100% of patients in the SJM group anticoagulated. The 7-year actuarial survival rate including early mortality was 79.3 +/- 4.6% for the Hancock and 93.9 +/- 3.0% for the SJM group (p less than 0.01). The survival rate was significantly higher in the SJM group than that in the Hancock group. The 7-year actuarial event free rate of the valve-related complications in the Hancock and SJM groups were as follows; thromboembolism 88.6 +/- 3.8% vs 95.0 +/- 2.8% (NS), hemorrhage, 94.0 +/- 3.0% vs 98.7 +/- 1.8% (NS), paravalvular leak 92.6 +/- 3.2% vs 97.4 +/- 1.8% (NS), infection 93.9 +/- 3.0% vs 100% (p less than 0.05), valve malfunction 78.0 +/- 5.2% vs 100% (p less than 0.001), overall valve related complications 58.9 +/- 5.9% vs 91.1 +/- 3.5% (p less than 0.001), reoperation for valve-related complication 83.1 +/- 4.6% vs 100% (p less than 0.01). The event free rate of reoperation for valve related complication in the Hancock group was significantly lower than that in the SJM group. The Hancock valve had the acceptable antithrombogenicity, but had the limited long-term durability.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Lillehei-Kaster aortic valve prosthesis. Long-term results in 273 patients with 1253 patient-years of follow-up

The Lillehei-Kaster aortic valve prosthesis was inserted in 313 patients between August 1975 and December 1984. Aortic valve replacement alone was done in 193 patients. Additional procedures included coronary artery bypass grafting in 62 patients, mitral valve replacement in 22, mitral valvuloplasty in 8, and miscellaneous procedures in 28. The 273 patients discharged from the hospital are the basis of this report. They have been followed up for 1253 patient-years. The range of follow-up is 1 to 11 years, and the mean is 4.6 years. The 5-year survival rate for all patients was 68%, whereas for aortic valve replacement alone it was 76%. The incidences of embolism, thrombosis, bleeding, periprosthetic leak, valve infection, and reoperation per 100 patient-years were 1.5, 0.2, 2.0, 0.8, 0.7, and 1.3, respectively. The 5-year rates of freedom from embolism, thrombosis, bleeding, periprosthetic leak, valve infection, reoperation, and any valve-related complication were 94%, 99%, 91%, 96%, 97%, 94%, and 76%, respectively. Four of 16 patients who required reoperation had a properly functioning valve whose effective orifice area was too small for the cardiac output. Each of these valves was of the smaller size. There were no instances of mechanical valve failure. The Lillehei-Kaster aortic valve prosthesis is an excellent aortic valve substitute in the larger sizes. It has an extraordinary record for mechanical durability and an excellent resistance to thromboembolism in patients receiving proper anticoagulation. The incidence of perivalvular leak and infection is similar to that of other prosthetic valves. However, it is not to be recommended in the smaller sizes because of an unfavorable ratio of effective orifice area to tissue diameter.     

Valve replacement for congenital valvular disease

Among 365 cases of mitral and aortic valve replacement (MVR, AVR) done in our institute during the period between 1968 and 1983, there were 20 congenital cases (5.5%), who were pointed out to have valvular disease since birth or early childhood and had no evident history of infectious disease. Mean ages at operation of MVR and AVR groups were 5.6 +/- 3.6 and 22.4 +/- 6.0 years respectively. Predominant pathology of mitral valve was regurgitation in 9 and stenosis in 2 cases. Seven cases were associated with other cardiac anomalies. Cumulative follow-up period was 34.3 patient-years (p-y). There were 3 late deaths resulted from xenograft calcification. In AVR group, predominant pathology of the valve was regurgitation in 8 cases and stenoregurgitation in one case. All cases were associated with other cardiac anomalies. There were 2 late deaths within the cumulative follow-up period of 39.5 p-y. Cumulative survival rates at 15 years, both in MVR and AVR groups were lower in congenital group than in the group of acquired disease. The incidences of prosthesis malfunction, prosthesis related complication and late death in the both MVR and AVR groups were higher in congenital group, when compared to that in the group of acquired disease.     

Case report of a malfunctioning SJM 19 A aortic valve prosthesis requiring reoperation

The patient was a 56-year-old female diagnosed with poor lung function who had undergone an aortic valve replacement 10 years ago, receiving an SJM 19 A prosthetic valve. She suffered from dyspnea and chest pain with postural change. Her anticoagulation level was maintained therapeutic. A cinefluoroscopy showed that one of the leaflets in the prosthetic valve was not moving. The aortic peak pressure gradient was calculated to be 68 mmHg using Doppler echocardiography. The patient's clinical condition improved after thrombolytic therapy with urokinase, but a complete normalization of her prosthetic discs was not obtained, so the patient was treated surgically. After an aortotomy, a pannus formation covering the entire SJM 19 A valve was observed. The aortic annulus was estimated to be 16 mm in diameter after the excision of the SJM 19 A valve and required before a larger prosthesis could be inserted. A SJM 19 HP valve was then anchored to the enlarged annulus. Her postoperative course was uneventful. We report a case requiring reoperation after a small aortic mechanical valve prosthesis implanted 10 years previously was damaged by thrombosis and pannus. Pannus formation on small aortic prosthesis easily caused hemodynamic obstructions and mechanical failure. Intensive evaluation with Doppler echocardiography and cinefluoroscopy is required for such patients.     

Long-term clinical results after mitral valve replacement with the Bj?rk-Shiley prosthesis

The experience of 810 mitral valve replacements performed during a 15-year period (1969 to June 1983) is reported. All but one patient received a Bj?rk-Shiley disc valve. Five different Bj?rk-Shiley models were used (Delrin, n = 51; standard pyrolytic carbon, n = 307; convexo-concave with an opening angle of 60 degrees, n = 229; convexo-concave with an opening angle of 70 degrees, n = 123; and the Monostrut valve, n = 99). The follow-up was 99.8% complete and covered 4614 patient-years (mean 6.0 years). An autopsy was performed in 77% of all fatalities. Early mortality was 5.7% and decreased during the study period. The 5-, 10-, and 15-year actuarial survival rates (early mortality excluded) were 78%, 62%, and 51%, respectively, and the complication-free survival rates at the same time intervals were 67%, 51%, and 36%. Seven percent of early deaths and 25% of late deaths were valve related, and most of these were due to valve thrombosis. The incidence of valve thrombosis was significantly (p less than 0.0005) reduced after the introduction of the convexo-concave valves, and this reduction was achieved without any increase in bleeding complications. The only patient-related factor found to be related to postoperative thromboembolism was a history of preoperative embolism (p less than 0.05). Most events occurring after implant (death, embolism, valve thrombosis, reoperation, and valve failure) had a peak incidence during the first postoperative year, whereas anticoagulant-related bleedings occurred at a constant rate of 1.2/100 patient-years. The linearized incidence of embolism was 1.6/100 patient-years (actuarial incidence at 5 and 10 years 6.9% and 13.0%, respectively). Seven strut fractures occurred (0.2/100 patient-years, actuarial incidence at 5 and 10 years 1.1%), as did five instances of prosthetic valve endocarditis (0.1/100 patient-years, actuarial incidence at 5 and 10 years, 0.7% and 1.3%). A new concept of valve failure is presented and includes a distinction between events related to the surgical procedure (treatment failure; 1.9/100 patient-years, actuarial incidence at 5 and 10 years 11.0% and 13.5%) and events possibly related to the prosthesis (prosthetic failure; 1.1/100 patient-years, actuarial incidence at 5 and 10 years 7.0% and 8.0%).