• Journal of Chest Surgery
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• v.26 no.9
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• pp.677-685
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• 1993

Experience with bileaflet mechanical valve replacement at the Inha Hospital in 192 patients, operated on from June 1986 until April 1993. Two hundred fourty-one prostheses [51 Duromedics, 79 St.Jude Medical, and 111 CafboMedics]were implanted during the total 195 operations. Mitral valve replacment[MVR]was done in 113 cases, aortic valve replacement[AVR]in 34, tricuspid valve replacement[TVR]in 2, and double valve replacement[DVR]in 46 cases.Of the total patients, 63.0% were women and 37.0% were men. The mean age of the patients was 40.8 years, ranged from 14 to 67years. Overall early mortality was 9.2\ulcorner%[18 out of 195]; 9.7%[11 out of 113]for MVR, 14,7% [5 out of 34]for AVR, and 4.3%[2 out of 46]for DVR. All of the operative survors were followed over a period of one to 83 months with a mean of 37 months, for total 543 patient-years. So far, eleven patients[6.7% of the long-term survivors]were lost to follov-up after a mean postoperative follow-up of 22.8 months. There were nine late deaths; three deaths due to prostetic valve endocarditis, two due to persistent heart failure, one due to cerebral hemorrhage, one due to aortic dissection after Bentall oreration, and two sudden deaths. Actuarial survival rate at 6.9 years was 94.8%, There were seventeen valve-related complications; three prosthetic valve thromboses, three thrombembolisms, three instances of prosthetic valve endocarditis, two paravalvular leakages, and six hemorrhagic complications related to anticoagulation. The actuarial rate of freedom from all valve-related complications at 6.9years was 91.3%. There were significant decreases in the heart size postoperatively that can be demonstrated by comparison of cardio-thoracic ratios on simple chest X-ray and left ventricle dimensions on echocardiography. We conclude that this midterm follow-up shows good results in terms of hemodynamics and durability although further long-term evaluations are mandatory.

• Journal of Chest Surgery
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• v.25 no.5
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• pp.518-525
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• 1992

50 months experience with St-Jude Medical Cardiac Valve Prosthesis The St. Jude Medical valve has become our mechanical valvular prosthesis of choice because of favorable hemodynamic results that associated with marked clinical improvement and low incidence of thromboembolism. The data for this study was collected from April 1986 to May 1990, four years period. There were total of 110 patients[female 53, male 58] in this series with 22 isolated aortic valve, 66 isolated mitral valve, 20 double valve, 2 tricuspid valve replacement. The mean follow up time was 23 months. Postoperatively, 77% of cases were in New York Heart Association[NYHA] functional class I, and mild and moderate symptoms[NYHA II ] were present in 20% and there were very few patients remaining in higher functional classifications. In postoperative echocardiographic study showed marked improved cardiac function. The overall early mortality was 5.4% and was higher after double[13.3%] and mitral valve replacement[5.6%] and the late mortality was one case after mitral valve replacement due to endocarditis. The cause of death in early mortality was attributed to heart failure, acute renal failure, sepsis, etc.

• Journal of Chest Surgery
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• v.24 no.11
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• pp.1090-1097
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• 1991

Between January 1981 and January 1991, 554 patients underwent prosthetic valve replacement. A bioprosthetic valve was replaced in 238 cases and mechanical valve 316 cases. Thirty-eight patients underwent 40 reoperations for repair or replacement, an average of 53.6 months after initial implantation. There were 21 women and 19 men, aged 12 to 60 years[mean 35.3]. A bioprosthetic valve was implanted in 31 cases and a mechanical valve in 9 cases for initial operation. Indications for reoperation were primary tissue failure in 23 cases[57.5%], endocarditis in 9[22.5%], periprosthetic leak in 4[10%]. and valve thrombosis in 4[10%]. Operations performed included 5 aortic valve replacements, 26 mitral valve replacement, 8 double valve replacements, and 1 thrombectomy. A mechanical valve was replaced in 33 cases[84.6%] and a bioprosthesis in 6[15.4Zo] for reoperation. A second reoperation was required in 2 patients. Surgical mortality was 10% . Among the 34 early survivors followed-up for an average of 19.8 months. there was 1 late death and 3 were lost to follow-up. Among the 30 late survivors being followed up, 28[93.3%] remained in New York Heart Association Class I or II and two in Class III [6.7%].

• Journal of Chest Surgery
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• v.27 no.10
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• pp.858-861
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• 1994

Prosthetic valve thrombosis is rare but it is one of fatal complication after heart valve surgery. Improvements of the valve design and the material have decreased the frequency of thrombosis but have not eliminated completely. And some cases of prosthetic valve thrombosis during pregnancy were reported inspite of adequate anticoagulation therapy.Urgent surgical intervention is indicated for prosthetic valve thrombosis but it is associated with high operative risk, therefore medical thrombolytic therapy such as urokinase or streptokinase therapy is regarded as an alternative therapy. This is a case report of the successful thrombolytic therapy for valve thrombosis in a pregnant patient after mechanical mitral valve replacement.

• Journal of Chest Surgery
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• v.28 no.9
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• pp.822-828
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• 1995

This paper reports 15 native valve endocarditis cases had surgical operation in the past 10 years at the department of Cardiovascular and Thoracic Surgery, Chonbuk National University Hospital. In this study, 10 cases out of 15 were in class I or II by the New York Heart Association functional classification. None of the cases had a history of taking addictive drugs. Five cases were congenital heart disease, three cases were rheumatic heart disease and two cases were degenerative heart disease. Thus 10 cases had the underlying disease. All cases had antibiotics treatment for 3 to 6 weeks before operation. In the culture test, only four cases were positive in the blood culture and one case was positive in the excised valve culture. Organisms on blood and valve culture were Streptococcus epidermis, Streptococcus viridans, Staphylococcus aureus and Staphylococcus epidermidis. In the 10 cases without ventricular septal defect, the aortic valve was involved in four, mitral in four, both in two and involved valves in the 5 cases with ventricular septal defect were tricuspid in three, pulmonic in two. Eight cases had operation because they showed moderate congestive heart failure due to valvular insufficiency and vegetation with or without embolism. Seven cases had operation because they showed persistent or progressive congestive heart failure and/or uncontrolled infection. Five cases with ventricular septal defect underwent the closure of ventricular septal defect, vegetectomy and leaflet excision of the affected valves without valve replacement. In the cases without ventricular septal defect, the affected valves were replaced with St. Jude mechanical prosthesis. Postoperative complications were recurrent endocarditis in two, embolism in one, allergic vasculitis in two, spleen rupture in one and postpericardiotomy syndrome in one. At the first postoperative day, one case died of cerebral embolism. At the 11th postoperative month, one case died of recurrent endocarditis and paravalvular leakage in spite of a couple of aortic valve replacement. In the survived cases[13 cases in this study , all cases but one became class I or II by the New York Heart Association functional classification.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.247-248
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• 1998

The effect of unattached valve leaflet on flow field downstream of a floating and flapping polyurethane heart valve prosthesis was investigated. With a triggering system and a time-delay circuit the instantaneous velocity field downstream of the valve was measured by particle image velocimetry (PIV) in conjunction with the opening posture of a flexible valve leaflet during a cardiac cycle. Reynolds shear stress distribution was calculated from the velocity fields and wall shear stress was directly measured by hot-film anemometry (HFA). The floating motion of the valve leaflet resulted in the reduction of pressure drop and recirculating flow region downstream of the valve.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.297-303
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• 1998

The sinus distal to the prosthetic heart valve influences the valve closure behavior and velocity field near the valve, therefore affects the hydrodynamic performance of the prosthetic heart valve. In order to study the effects of valve distal geometry on the hydrodynamic performance of the prosthetic valves, mechanical bileaflet valve(SJMV), monoleaflet polymer valve(MLPV) and trileaflet polymer valve(FTPV) are inserted in the test sections which have the straight and the sinus shape distal to the valve. Leakage volumes and systolic mean pressure drops are measured in the pulsatile mock circulation flow loop. Leakage volumes are slightly less and systolic mean pressure drops are higher in the sinus test section comparing to those in the straight test section, but the differences are statistically insignificant. Flow waveforms are analyzed in order to predict the valve closure behavior. The distal sinus does not affect the closure of the MLPV, but early valve closure of SJMV is observed in the sinus test section. This effect is more significant in FTPV, and the reverse flow peak of FTPV is reduced in the sinus test section. Therefore the sinus distal to the valve can reduce the reverse flow jet caused by sudden valve closure.

• Journal of Chest Surgery
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• v.54 no.1
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• pp.25-30
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• 2021

Background: Life-long anticoagulant therapy is mandatory for patients who undergo heart valve replacement with implantation of a mechanical prosthesis. The aim of this study was to investigate the effects of a nurse-led patient educational program concerning oral anticoagulant therapy intake after heart valve replacement surgery on patients' knowledge of important parameters of anticoagulant administration. Methods: In this single-center study, 200 patients who underwent surgical implantation of a mechanical prosthesis were divided into 2 groups. The control group received the basic education concerning oral anticoagulants, while the intervention group received a personalized educational program. Results: Personalized education was correlated with a better regulation of therapeutic international normalized ratio (INR) levels and adequate knowledge among patients. Therapeutic levels of INR were achieved in 45% of the patients during the first month, 71% in the third month, and 89% in the sixth month after discharge in the intervention group, compared to 25%, 47%, and 76% in the control group, respectively. Patients' satisfaction with the information was higher in the intervention group than in the control group. The percentage of satisfaction reached 80% for the intervention group versus 37% for the patients of the control group. Conclusion: The implementation of the nurse-led educational programs was associated with improved clinical results and increased adherence to oral anticoagulant treatment.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.50-55
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• 2004

Background: Transcranial Doppler ultrasonography (TCD) can detect microembolic signals (MES) in the patients with a potential embolic source. Clinical significance of MES has not been demonstrated in patients with prosthetic mechanical heart valves. We studied the correlation between cerebral thromboemoblic events after the mechanical heart valve surgery (MHVS) and residual MES during TCD monitoring with 100% oxygen inhalation in patients with mechanical heart valves. Material and Method: Twenty patients with previous cerebral thromboemoblic events after MHVS and a sex- and age-matched control group (n=30) were studied. TCD monitoring was performed from unilateral middle cerebral artery. After baseline monitoring for 20 minutes, 61 of oxygen was inspired for 40 minutes. Result: The site of valve and the duration after MHVS of the patients did not differ from those of controls. During baseline monitoring, there was no significant difference in MES prevalence or counts compared to controls. During oxygen inhalation, patients showed a higher MES prevalence (55%, 27.6%, p=0.045) and a more frequent MES counts (p=0.027) compared to controls. Conclusion: TCD monitoring with oxygen inhalation may be useful to differentiate clinically significant MES in patients with mechanical heart valve.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.328-334
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• 2004

There are only limited numbers of reports about long-term results of tricuspid valve replacement(TVR) with bioprosthetic and mechanical prostheses. We analyzed risk factors for tricuspid valve replacement and compared long-term clinical results of bioprosthetic and mechanical valves in tricuspid position. Material and Method: We reviewed 77 cases of TVR, which were performed between October 1978 and December 1996. Mean age was 38.8 15.9 years. Bioprostheses were implanted in 26 cases and mechanical prostheses were implanted in 51 cases. Result The operative mortality was 15.6% and late mortality was 12.3%. Survival for bioprosthetic and mechanical valve group at 5, 10 and 13 years was 81.3% vs. 100%, 66.1% vs. 100%, 60.6% vs. 100% (p=0.0175). Free from valve related re-operation for bioprosthetic and mechanical valve group at 5, 10 and 13 years was 100% vs. 93.9%, 100% vs. 93.9% and 58.3% vs. 93.9% (p=0.3274). Linealized incidences of valve related re-operation for bioprosthetic and mechanical valve group was 2.27 %/patient-years and 1.10 %/patient-years. Risk factor analysis showed that presence of preoperative ascites, hepatomegaly larger than 2 finger breaths, poor preoperative NYHA functional class and number of tricuspid valve replacement were risk factors for early mortality, and the use of bioprosthetic valve and number of open heart surgery were risk factors for late mortality. Conclusion: Long-term survival of mechanical valve was superior to bioprosthetic valve in tricuspid position. We recommend mechanical valve in tricuspid position if the patient can be closely followed up.