• Journal of Chest Surgery
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• v.27 no.2
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• pp.114-121
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• 1994

St. Jude Medical cardiac valve replacement was performed in 135 consecutive patients from Aug.1986 to Dec. 1991.72 had mitral, 28 had aortic, 1 had tricuspid and 34 had double valve replacement. The hospital mortality rate was 4.4% & the late mortality rate was 3.7 %. Follow-up was done on 115 surviving patients:mean follow-up period was 29.78 $\pm$ 18.32 months. Paravalvular leakage was observed in two patients, possible prosthetic valvular endocarditis wasobserved in one patient and other specific valve-related complications were none. The overall actuarial survival rate at 6 years were 91.6% in total, 96.4% in aortic, 95.5 % in mitral and 81.9 % in double valve replacement.We concluded, therefore that good clinical results and a low complication rate could be achieved with St. Jude Medical valve in short-term follow-up & long-term follow-up was also necessary.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.291-296
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• 1998

A new mechanical heart valve prosthesis has been designed appling systematic design methodology. The function of the heart valve was defined, and search for design variation has been carried out according to the functional structure, Optimal model among the various variations was determined in view of the design specificationn. Proto type valve was fabricated and test has been carried out using a mock circulation system. It has been observed that the pressure profile, cardiac output and behavior characteristics are generally satisfactory.

• Journal of Chest Surgery
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• v.33 no.8
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• pp.643-647
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• 2000

From March 1988 to June 1994, 275 CarboMedics cardiac valve prostheses(199 mitral, 70 aortic and 3 tricuspid) were implanted in 226 consecutive patients(mean age 39 years, male/female 90/136) by one surgical team operating on adult cardiac patients at Kyungpook University Hospital. Total follow up represented 16,848 patient-months(mean 76 months) and follow up rate was 96%. One hundred and forty-nine patients(66%) wer in NYHA functional class III or IV preoperatively, and 204 patients(99.5%) were in class I or II postoperatively. Early mortality was 4.9% and late death was 9.3%. The actuarial survival at 81 months was 86.l2$\pm$3.1%. The linearized incidence of valve-related death, prosthetic valve thrombosis, anticoagulation-related hemorrhage, non-structural dysfunction and reoperation were 0.71%, 0.43%, 0.07%, 0.21%, and 0.14% respectively. The 81-month rate of freedom from all valve related complications and deaths including hospital mortality was 88.1$\pm$2.5%. Thee facts suggest that the CarboMedics cardiac valve has excellent result, low incidence of valve-related complications and no structureal deterioration.

• Journal of Chest Surgery
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• v.24 no.2
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• pp.161-170
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• 1991

Clinical results with the Mechanical cardiac valves were reviewed for 261 patients who underwent cardiac valve replacement from September, 1985 to July, 1990. of the Mechanical valves used, 156 were Carbomedics, 109 Duromedics, 52 St. Jude and 11 Bjork-Shiley. Overall hospital mortality was 14 out of 261[5,36%]: 9 out of 159[5.66%] for MVR, 1 out of 35[2.86%] for AVR and 4 out of 67[5.96%] for DVR[AVR+MVR]. Two hundred and forty seven operative survivors were followed up for a total 466.8 patient-years, ranged from 1 month to 4.9 years [a mean 1.8 years] and the follow up was 96.0%. There were 12 valve-related complications: three from thromboembolism, three from valve thrombosis, three from prosthetic valve endocarditis, two from paravalvular leak and the other one from hemorrhage. Actuarial rate free from all valve-related complication at 4.9 years was 96$\pm$1.3%. There were 11 late deaths: two from thromboembolism, one from valve thrombosis, one from prosthetic valve endocarditis, one from hemorrhage and the others 6 from non-valve-related complications. Actuarial survival rate at 4.9 years was 94$\pm$2.0%. 96$\pm$3.0% for MVR, 94$\pm$4.2% for AVR and 91$\pm$3.7% for DVR[AVR+MVR]. And there are 7 reoperations: three from paraprosthetic leak, two from prosthetic valve endocarditis and two from valve thrombosis. Actuarial rate free from reoperation at 9 years was 96$\pm$2.9%. On the basis of this 4.9 years of experience, the pyrolytic carbon mechanical valves appears to be an excellent mechanical prosthesis for cardiac valve replacement, in terms of hemodynamic performance, low mortality and low thrombogenecity.

• Journal of Mechanical Science and Technology
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• v.17 no.9
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• pp.1316-1323
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• 2003

This paper presents a structural analysis on the rigid and deformed motion of the leaflet induced by the blood flow required in the design of a bileaflet mechanical heart valve (MHV) prosthesis. In the study on the design and the mechanical characteristics of a bileaflet mechanical heart valve, the fluid mechanics analysis on the blood flow passing through leaflets, the kinetodynamics analysis on the rigid body motion of the leaflet induced by the pulsatile blood flow, and the structural mechanics analysis on the deformed motion of the leaflet are required sequentially and simultaneously. Fluid forces computed in the previous hemodynamics analysis on the blood flow are used in the kinetodynamics analysis on the rigid body motion of the leaflet. Thereafter, the structural mechanics analysis on the deformed motion of the leaflet follows to predict the structural strength variation of the leaflet as the leaflet thickness changes. Analysis results show that structural deformations and stresses increase as the fluid pressure increases and the leaflet thickness decreases. Analysis results also show that the leaflet becomes structurally weaker and weaker as the leaflet thickness becomes smaller than 0.6 mm.

• Journal of Chest Surgery
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• v.24 no.1
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• pp.26-35
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• 1991

From January 1984 to June 1990, 188 patients have undergone cardiac valve replacement [114 MVR, 27 AVR, 47 Multiple valve replacement] with the St. Jude Medical prosthesis. The early mortality rate was 6.9%. The most common cause of early death was low output syndrome. There were no cases of valve-related early death. The risk factors for early death were advanced preoperative NYHA functional class [> IV], and prolonged ECC and ACC time. The 175 early survivors were followed-up for a total 372.7 patient-year over a period of 2 to 74 months [Mean $\pm$SD: 25.6$\pm$18.6 months]. During follow up, 12 patient died and late mortality rate was 6.9%. There were three valve-related late deaths: two were due to valve thrombosis and one was due to hemorrhage. Most late deaths [58%, 7/12] were from cardiac non-valvular causes. Valve-related complications occurred at a linearlized rate of 3.5% /pt-yr. Embolism occurred at a rate of 0.8% /pt-yr. There were three cases of valve thrombosis [0.8% /pt-yr: two fatal]. Hemorrhage due to anticoagulant occurred in 5 patients and a rate of 1.3% pt-yr [one fatal]. Five-year actuarial survival rate was 86.5 $\pm$5.1% and 97% of patient were in NYHA functional class I or II at three months postoperatively.

• Journal of Chest Surgery
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• v.24 no.2
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• pp.171-181
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• 1991

Result of St. Jude Medical valve replacement are presented in 106 patients who underwent operation from January 1985 through July 1989. The patient were 52 males and 56 females. Total 136 of St. Jude Medical valves were implanted; 91 in mitral position, 45 in aortic position. The hospital mortality rate was 5.7%o[6 patients] and the late mortality rate was 2.0%[2 patients]. The causes of death were low cardiac output in 5, iatrogenic right ventricular rupture in 1, heart failure in 1, ventricular arrhythmia in l. And, the causes of valve related complication were anticoagulant related hemorrhage in 5 patients[0.03% /patient-year] and thromboembolism[0.01% /patient-year] in 2 patients. In conclusion, the performance of the St. Jude Medical valve compare most favorably with other artificial valves. But it remains still hazards of mechanical prosthesis such as thromboembolism and anticoagulant related hemorrhage.

• Journal of Chest Surgery
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• v.25 no.1
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• pp.57-65
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• 1992

St.Jude Medical cardiac valve replacement was performed in 322 patients: 191 had mitral, 58 had aortic, 72 had double valve and 3 had tricuspid valve replacement. Motality rate in early period was 2.8%[9 patients]. The most common cause of early death was low cardic output syndrome. Follow up extended from 1 to 90 months[mean: 34 months] in 292 patients among 313 in all surviving patients [93.6%]. There were thrombolic complications in eighteen patients. The probability of free from thromboembolism at 5 yerars in MVR, AVR and DVR were 84.7%, 91.8% and 90.2% respectively. And also, actuarial event free rate at 5 years in MVR, AVR and DVR were 80.1%, 82.2%, and 81.4% respectively. There were fourteen late death during follow up period: six from thromboembolism, one from hemorrhage and the others from non valve related -or unknown complications. The acturial survival rate at 5 years were 93.1% in mitral, 92.1% in aortic and 97.1% in double valve replacement. In conclusion, the performance of the St. Jude Mecanical valve compares most favorably with other artificial valves. But it remains still hazards of mechanical prosthesis such as thromboembolism and anticoagulant related hemorrhage.

• Journal of Chest Surgery
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• v.34 no.9
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• pp.686-691
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• 2001

Background: The Duromedics valve has been used in Korea since 1982, however, but there were no long term clinical results that have been reported. This paper presents the long term clinical results of Duromedics valve implanted in Seoul National University Hospital. Material and method: Between 1987, 23 patients underwnet cardiac valve replacement with Duromedics mechanical valve. There were 8 mitral valve replacements, 5 aortic valve replacements, one tricuspid valve replacement, 6 aortic and mitral valve replacements, and one mitral and tricuspid valve replacement. There were 12 men and 11 women. The mean age was 35$\pm$10(15~52) years. We evaluated the clinical performance of Duromedics cardiac prosthesis. Result: The early operative mortality was 4.3%(1/23) and the late morlatity was 4.3%(1/23). Causes of death were low cardiac output syndrome and structural valvular failure. The mean follow-up duration was 133$\pm$43(8~157) months. There were 3 reoperations. The causes of reoperations were thrombosis and structural failure and nonstructural valvular failure. The actuarial survival rate at 10 years was 90.9%. Conclusion: Although the number of patients was not sufficient for effective clinical study, the long term clinical results of Duromedics valve was relatively good and there was no structural defect in this mechanical valve. However, more research is needed in the future.

• Journal of Chest Surgery
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• v.27 no.4
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• pp.272-280
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• 1994

Total 400 St.Jude Medical Bileaflet Valves were implanted in 336 pts from January 1983 to June 1993; 64 were aortic, 205 were mitral, 64 were double valve and 3 were tricuspid position. The follow up period extended from 6 months to 10 years[mean 24.3 months]. Male to female ratio was 1:1.7. There were total 27 deaths[cardiac related 20, cardiac non-related 7]. Overall mortality was 2.9%/pt-yr. There were 10 early deaths[3.0%] and 10 late cardiac related deaths [3.0%]. Prosthetic valve related complications occurred in 19 patients[5.7%] and among them, seven died; four died of thromboembolic events, two died of anticoagulants therapy related hemorrhagic complications and one died of bacterial endocarditis. NYHA class improved significantly especially in aortic valve replacement and double valve replacement. In AVR cases, the mean NYHA was 2.8 preoperatively and 1.3 postoperatively. And in DVR cases, 3.3 preoperatively and 2.2 postoperatively. The decision to employ a particular prosthesis was made according to the anticipated or known complications of the valve. The St.Jude Medical Valve retains all the hazards of other mechanical valves, most notably, thromboembolism. But the hemodynamic performance of St.Jude Medical Valve compared most favorably with other substitute valves in many reports. 0ur experience didn`t show any differences compared other authors in terms of valve related complication. So we concluded St. Jude Medical Valve can be primarily considered in the selection of artificial valve except in the patients when the usage of anticoagulant therapy is contraindicated.