• Journal of Chest Surgery
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• 제24권2호
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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.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 추계 학술대회논문집
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• pp.203-206
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• 2004

In this study, a numerical analysis has been performed for a three-dimensional pulsatile blood flow associated with the elastic blood vessel and curved bileaflet for multiple cycles in terms of fluid-structure interaction. Here, blood has been assumed as a Newtonian, incompressible fluid. Pressure profiles have been used as boundary conditions at the ventricle and the aorta. From this analysis, the motion of the leaflet has been observed with fluttering phenomenon and rebound, and the flow fields of blood have been obtained with recirculation and regurgitation. The results can contribute to the development of design methodology for the curved bileaflet mechanical heart valve.

• Journal of Chest Surgery
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• 제26권2호
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• pp.158-159
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• 1993

The hemorragic episode is the major problem of mechanical prosthesis, because of the necessity for anticoagulant therapy to prevent complication of thromboembolism. Double valve replacement was performed to 42 year old male due to aortic stenoinsufficiency and mitral stenosis. For anticoagulant therapy, the patient has been given wafarin under the control of prothrombin time 0.5-2 times of normal) in the our hospital. The patient was injuried the right pelvic area by waves in the beach 4 years after double valve replacement. Pelvic MRI scan showed huge hematoma in the right pelvic cavity. The patient was operated removal of intrapelvic hematoma.

• 대한의용생체공학회:의공학회지
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• 제17권2호
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• pp.215-220
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• 1996

Impact force and strains induced by impact between the occluder and the struts have been measured with force sensor and strain gages. The maximum reaction force was about 25N, and the calculated impact force on the root of the struts amount about 9-17W. Impact force on the inlet strut is greater than that of the outlet strut, but the strain on the outlet strut is much higher than that of the inlet strut. These values might cause severe damage on the valve in the critical cases. The results of this study may be extended for the analysis of the endurance limit and optimal design of the struts and occluder.

• Journal of Chest Surgery
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• 제27권12호
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• pp.1031-1035
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• 1994

Mechanical valve thrombosis is a serious and potential lethal complication unless early diagnosis & prompt therapy are made. We have been experienced 3 cases of valve thrombosis. From Aug. 1988 to July 1994, reoperations of mitral valve replacement [MVR] with mechanical prostheses [all mitral] were performed in three patients[2 men, 1 woman] due to valve thromboses. All three patients were diagnosed by means of cineradiography. Preoperative status of was shock status and he was applied intra-aortic balloon pump [IABP]. All three cases of prosthetic valve failure [PVF] were treated by Redo-MVR. Time intervals of reoperations were 5months, 40months, and 35months, respectively. In all cases, valve thromboses were excised successfully. Cineradiography provided an accurate diagnosis in all cases, which was utilized as safe, reliable & noninvasive imaging modalities. There were no operative death & complication. All three patients were fully recovered and returned to their employements, and active lives.

• Journal of Chest Surgery
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• 제27권12호
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• pp.995-1001
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• 1994

The CarboMedics valve prosthesis is a relatively new. low profile bileaflet prosthesis. During a 6 year period from Aug. 1988 to July 1994. 158 patients had CarboMedics prostheses implanted in the mitral [n=94], aortic [n=25], or aortic and mitral [n=39] in National Medical Center. Hospital mortality was 9.4% and the main cause of death was low output syndrome. Follow up was 96% complete, with 365.4 patient-years and a mean follow up of 30 months [ range 1 to 72 months ] . The overall actuarial 6 year survival rate was 91.61 3.47% and actuarial 6year freedom from all valve related complications was 73.9 7.67%. The linearized incidence of vavle related complications was as follows: thromboembolism 1.37%/patient-year ; valve thrombosis 0.82%/ patient-year ; anticoagulant related hemorrhage 0.85%/patient-year ; perivalvular leakage 0.55%/paitent-year: prosthetic valve endocarditis 0.82%/patient-year ; reoperation 1.37%/patient-year. There were no instances of structural failure. We conclude that the Carbomedics valve has a low rate of complications that further improves the quality of life in patients with heart valve prostheses.

• Journal of Chest Surgery
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• 제26권10호
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• pp.753-760
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• 1993

The CarboMedics valve is a bileaflet prosthesis with excellent hemodynamic characteristics, but the long term surgical experience with this valve, its durability and its biocompatibility are unknown. During a 5 year period from october 1988 to July 1993, 748 prostheses [402 mitral, 261 aortic, 58 tricuspid, 27 pulmonic] were inserted in 552 patients [mean age 40.2 years]. The operative mortality was 6.6% [37/560, 13.2% in age group below 15 years and 5.7% above 15 years]. and the main causes of death were complex congenital malformation and left ventricular failure. Follow up was totaled 1182 patient- years and mean follow up was 28.3 months/patient. No structural failure has been observed. Hemorrhage was the most frequent valve related complication[1.78% / Patient-year]. Embolism occurred at a rate of 0.93% / Patient-year. There were 5 cases of valve thrombosis [0.42% / Patient-year, two fatal]. There occurred 11 late deaths[6 valve related] and 42 valve related complications. Actuarial survival at 5 years is 97.18 0.94% and actuarial complication free survival at 5 years is 89.07 1.54%. In summary, the CarboMedics valve stands for a durable valve substitute, with low valve related complications.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.167-171
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• 1996

Impact force and strains induced by impact between the occluder and the struts have been measured with force senfor and strain gages. The maximum reaction force was about 25N, and the calculated impact force on the root of the struts amount about $9{\sim}17N$. Impact force on the inlet strut is greater than that of the outlet strut, but the strain on the outlet strut is much higher than that of the inlet strut. These values might cause severe damage on the valve in the critical cases. The results of this study may be extended for the analysis of the endurance limit and optimal design of the struts and occluder.

• Journal of Chest Surgery
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• 제22권3호
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• pp.393-401
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• 1989

Between Dec. 1984, and May, 1988,96 prostheses were implanted in 80 patients at Dept. of Thoracic k Cardiovascular Surgery of National Medical Center. 43 patients had mitral valve replacement, 21 underwent aortic valve replacement, and 15 had double valve replacement [Mitral k Aortic], and 1 had tricuspid valve replacement. Seventy-one cases [88.8 %] were in NYHA Class III or IV. The mean duration of follow up was 22.1 months and follow-up information was available for 74 [92.5 %] of the patients. The overall actuarial survival rate at 45 months was 93.05 % and overall hospital mortality was 10 %, late Mortality was 5 %. The linearlized incidence of thromboembolism [2.4%/pt-yr], thrombotic valve obstruction [1.6 %/pt-yr], anticoagulant related bleeding [0.8 %/pt-yr]. There were no fatal valve related complications. The blood was studied in 40 patients 1 year after valve operation. Hgb and reticulocyte count were within normal values and Serum LDH value was slightly elevated but it was not of clinical significance. In conclusion, Monostrut Bjork-Shiley valve prosthesis to be a reliable valve substitute with an acceptable incidence of complications.

• Journal of Chest Surgery
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• 제36권2호
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• pp.73-78
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• 2003

기능적 단심증에 대한 Fontan 술식은 수술 방법에 많은 변형을 거치면서 그 임상 성적 또한 향상되어 왔다. 그럼에도 불구하고 추적과정 중에 발생하는 치명적인 합병증은 장기 성적에 많은 영향을 미친다고 할수 있다. 따라서 이러한 합병증에 대한 수술적 치료가 필요하며 빈도 또한 증가하고 있다. 대상 및 방법: 1988년 4월부터 20n년 1월까지 Fontan 수술 후에 발생한 합병증에 대한 수술적 치료를 받은 16명의 환자를 대상으로 하였다. 재수술 당시 평균 연령은 8.8$\pm$5.5년이었다. Fontan수술에 적용된 술식은 심방-폐동맥 연결술 및 완전 체정맥-폐동맥 연결술이 각각 8예로 완전 체정맥-폐동맥 연결술 중 5예는 심장내 외측터널, 3예는 심장외 외측터널을 시행하였다. 이 중 천공을 추가한 경우가 5예 있었다. 재수술의 적응증은 잔존 우좌단락 6예, 폐정맥 협착 3예, 심방 조동 3예, 방실판막 폐쇄부전 2예, Fontan 유출로의 협착 1예, 단백상실성 장병증이 1예 있었다. 결과: 조기 및 만기 사망이 각각 3예 있었다. 잔존 단락이 있었던 환자에서는 2예에서 단락 부위를 일차 봉합하였고 2예에서는 체정맥과 폐정맥을 분리하기 위한 심방내 중격을 재형성하였으며 2명의 환자에서는 심장내 외측통로 및 부분 양심실 교정술로 전환하였다. 폐정맥이나 Fontan유출로의 협착이 있었던 4명의 환자에서는 3예에서 협착 부위 확장술을 시행하였고 1예에서는 좌폐 전절제술을 시행하였다. 심방 조동이 발생한 3예는 모두 심방-폐동맥 연결술에서 심장내 외측터널로 술식을 전환하였다. 2예의 방실판막 폐쇄부전 환자는 기계 판막 치환술을 시행받았으며 단백소실성 장병증이 발생한 1예는 개흉술을 통해 대동맥-폐동맥 측부 혈행을 폐쇄하였다. 4명의 환자에서 부정맥 치료의 추가적인 방법으로 냉동 절제술을 동시에 시행하였다. 결론: Fontan수술 후에 발생하는 합병증은 치료가 어렵고 상당한 유병율 및 사망률을 가지고 있다. 그러나 Fontan 생리에 대한 보다 깊은 이해와 수술 술기의 발전은 Fontan 수술 자체뿐 아니라 그 합병증의 치료 가능성을 증대시켰다. 비록 모든 환자에서 만족할 만한 결과를 얻지는 못하였으나 이러한 환자에 대한 적절한 외과적 치료로 생존환자에서 증상의 완화 및 기능적 분류의 호전을 볼 수 있었다.