• Journal of Chest Surgery
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• v.2 no.1
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• pp.77-84
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• 1969

Retrograde left cardioangiographic studies using Amplatz spring coil guide catheter were carried out in 30 cases of acquired mitral valvular diseases. Of these 12 cases were compatible with the clinical diagnosis which were made pre-angiocardiographically. Eighteen out of 30 cases were diagnosed as pure mitral stenosis or mitral insufficiency which had been clinically diagnosed as mitral stenoinsufficiency or mitral stenosis with aortic insufficiency. The rate of difference is 60%. Twenty-five cases or 83% of all cases were operated. Of these 6 cases, the degree of regurgitation through the mitral valves were able to be evaluated cardioangiography and were confirmed by open heart operation. The retrograde left cardioangiography is considered to be a useful tool in conclusive dianosis of clinically equivocal mitral valvular diseases.

• Journal of Biomedical Engineering Research
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• v.34 no.1
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• pp.40-45
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• 2013

The conventional simulators used the expensive commercial artificial heart with a limited performance, and focused on replicating the heart function. The arterial pressure is the key factor of the cardiovascular disease. The purpose of this study is to develop a simulator focused on the pressure wave. The simulator is composed of a step motor, slider-crank mechanism, piston-cylinder, two check valves, a elastic tube, and two reservoirs. With the changes of design parameters, the functions of the simulator were evaluated. The simulator shows the good agreement of the characteristics of the cardiovascular system.

• Journal of Chest Surgery
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• v.56 no.6
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• pp.456-459
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• 2023

Penetrating chest trauma may result in significant intracardiac injury. A traumatic ventricular septal defect is a rare complication that requires surgical management, particularly if heart failure ensues. We report a case of delayed repair of an outlet-type ventricular septal defect and perforation of the aortic and pulmonary valve leaflets following a stab wound. This report highlights diagnostic and surgical considerations and also presents an opportunity to review the conotruncal anatomy, which may be relatively unfamiliar to many adult cardiac surgeons.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1111-1117
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• 1996

Structural deterioration of the bioprosthetic xenograft valves due to primary tissue failure occurs in two modes: from fatigue lesions with tear and wear with or without calcification and from calcification with obstruction. Two groups of consecutive 56 patients with the Hancock porcine ortic valve(HM) and of 1 13 patients with the standard-profile onescu-Shiley bovine pericardial valve(ISM) explanted from mitral position at the time of re-replacement surgery for primary tissue failure at Seoul national University Hospital until 1994, were studied for clinical and pathological features. Their ages at primary implant were 31.9 $\pm$9.2 years In HM and 30.4$\pm$ 12.5 years in ISM. Hemodrnamic dysfunction of the failed mitral bloprostheses were predominantly insufficiency in HM(64.3%) and stenosis in ISM(51.3%)(p<0.001). Pathologic findings of the explanted mitral valves reflected these hemodynamic changes, revealing failure more often from tissue damage(tears and wears) in HM and more often from calcification in ISM(p< 0.001). Explant period(from primary implant to explant) was relatively short in ISM(8.7$\pm$2.6years), compared with the one in HM(10.4 $\pm$2.6 years)(p<0.001). In conclusion, both the Hancock and the lonescu-shiley valves would fail from calcification as well as issue damage. However, while the Hancock porcine valves in mitral position failed more frequently from tissue failure and insufficiency, the standard-profile lonescu-Shiley pericardial valves did from calcification and stenosis, especially in young pAtients . Although the possibility of less occurrence of valve failure from mechanical reasons may be expected with newer generation bloprostheses, it does not seem to Improve durability significantly unless further refinement in antimineralization is achieved. Therefore, clinical use of the glutaraldehyde-treated bioprosthetic valves is, at present, limited to the patients of advanced age groups.

• Journal of Chest Surgery
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• v.28 no.1
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• pp.23-30
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• 1995

From January 1985 to December 1992, of 1257 patients who underwent a heart valve replacement 210 [16.8% underwent reoperation on prosthetic heart valves, and 6 of them had a second valve reoperation. The indications for reoperation were structural deterioration [176 cases, 81.5% , prosthetic valve endocarditis [25 cases, 11.6% , paravalvular leak [12 cases, 5.6% , valve thrombosis [2 cases, 0.9% and ascending aortic aneurysm [1 case, 0.4% . Prosthetic valve failure developed most frequently in mitral position [57.9% and prosthetic valve endocarditis and paravalvular leak developed significantly in the aortic valve [40%, 75% [P<0.02 . Mean intervals between the primary valve operation and reoperation were 105.3$\pm$28.4 months in the case of prosthetic valve failure, 61.5$\pm$38.5 months in prosthetic valve endocarditis, 26.8$\pm$31.2 months in paravalvualr leak, and 25.0$\pm$7.0 months in valve thrombosis. In bioprostheses, the intervals were in 102.0$\pm$23.9 months in the aortic valve, and 103.6$\pm$30.8 months in the mitral valve. The overall hospital mortality rate was 7.9% [17/26 : 15% in aortic valve reoperation [6/40 , 6.5% in reoperation on the mitral prostheses [9/135 and 5.7% in multiple valve replacement [2.35 . Low cardiac output syndrome was the most common cause of death [70.6% . Advanced New York Heart Association class [P=0.00298 , explant period [P=0.0031 , aortic cross-clamp time [P=0.0070 , prosthetic valve endocarditis [P=0.0101 , paravalvularr leak [P=0.0096 , and second reoperation [P=0.00036 were the independent risk factors, but age, sex, valve position and multiple valve replacement did not have any influence on operative mortality. Mean follow up period was 38.6$\pm$24.5 months and total patient follow up period was 633.3 patient year. Actuarial survival at 8 year was 97.3$\pm$3.0% and 5 year event-free survival was 80.0$\pm$13.7%. The surgical risk of reoperation on heart valve prostheses in the advanced NYHA class patients is higher, so reoperation before severe hemodynamic impairment occurs is recommended.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.293-299
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• 1997

With the introduction of new cardiac prosthesis, it behooves surgeons and cardiologists to monitor its performance carefully. ATS (Advancing The Standard) prosthetic valve has been used first in Guro hospital in Korea, since August 1994. Between August 1994 and July 1995, 21 patients received 28 ATS prosthesis(9 aortic, 19 mitral).19mi1ra1 valves were implanted through the "Extended Transseptal Approach" 10 were ma e and 11 were female, ranging from 20 to 54 years of age(Mean age : 37 years). The follow up period 126 patient-months(mean 6.1 months), varied from 1 month to 12 months. NYHA functional class was improved significantly, from $2.9\pm0.7$ preoperatively to $1.4\pm0.5$ postoperatively. Ejection fraction was also improved from $55.5\pm6.1%$ preoperatively to 59.8 $\pm7.4%$ postoperatively. Lactic dehydrogenase(LDH) was used as an indicator of hemolysis. The value of LDH changed from 483.3 $\pm$ 162 lUlL preoperatively to $527\pm274$ lUff postoperatively with no clinical significailce. Valve related complications, such as thromboembolism, valve thrombosis, anticoagulant related hemorrhage and prosthetic valve endocarditis did not develop except one anticoagulant related intracranial hemorrhage. There were no mortalities. This experience encourages us to continue using the ATS prosthetic valve, and this study will help those patients who need to have their heart valves replaced. replaced.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.262-267
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• 2007

Implantation of allografts has increased widely with not only the availability of many allogenic bone but also allogenic soft tissues. The aim of tissue banking is to provide surgeons with safe tissues compatible with their intended clinical application. The incidence of tissue transplant-transmitted infection is unknown and can only be inferred from prospective studies. The possibility of donor-to-recipient disease transmission through soft tissue transplantation can be considered by reviewing the risk associated with other transplanted hard tissues. Viral, bacterial, and fungal infections have been transmitted via transplantation of soft tissue allografts such as skin, cornea, dura, pericardium. fascia lata, and heart valves. Corneas have transmitted rabies, Creutzfeldt-Jakob disease (CJD), hepatitis B (HBV), cytomegalovirus (CMV), herpes simplex virus (HSV), bacteria, and fungi. Heart valves have been implicated in transmitting tuberculosis, hepatitis B. HIV-1 and CMV. CJD has been transmitted by dura and pericardium transplants. Skin has transmitted CMV, bacteria, and fungi. Cadaveric skin, pericardium, dura, and fascia lata have been used in dental patients with intra-oral soft tissue injuries and GBR. This study is review of the considering transmission of infectious disease in allogenic soft tissues and guidelines of reducing the risk. Prior to use, many tissues are exposed to antibiotics, disinfectants, and sterilants, which further reduce or remove the risk of transmitted disease. Because some soft tissue grafts cannot be subjected to sterilization steps, the risk of infectious disease transmission remains and thorough donor screening and testing is especially important.

• Journal of Chest Surgery
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• v.46 no.4
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• pp.256-264
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• 2013

Background: Surgical treatment of infective endocarditis (IE) remains a challenge, especially in cases of multiple valve surgery. We evaluated the clinical outcomes of native valve IE and compared the outcomes of single valve surgery with those of multiple valve surgery. Materials and Methods: From 1997 to 2011, 90 patients underwent surgery for native valve IE; 67 patients with single valve surgery (single valve group) and 23 patients with multiple valve surgery (multiple valve group). The mean follow-up duration was $73.1{\pm}47.4$ months. Results: The surgical mortality in the total cohort was 4.4%. The overall survival (p=0.913) and valve-related event-free survival (p=0.204) did not differ between the two groups. The independent predictor of postoperative complications was New York Heart Association class (p=0.001). Multiple valve surgery was not a significant predictor of surgical mortality (p=0.225) or late mortality (p=0.936). Uncontrolled infection, urgent or emergency surgery, and postoperative complications were identified as independent predictors of valve-related morbidity, excluding multiple valve surgery (p=0.072). Conclusion: In native valve IE, multiple valve surgery as a factor was not an independent predictor of mortality and morbidity. The number of surgically corrected valves in native IE seems to be unrelated to perioperative and long-term outcomes.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.2
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• pp.443-450
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• 1995

An analysis of the dynamics of a mechanical monoleaflet heart valve prosthesis in the closing phase is presented. Employing the moment equilibrium principles on the occluder motion and the squeeze film dynamics of the fluid between the occluder and the guiding strut at the instant of impact, the velocity of the occluder tip and the impact force were computed. The dynamics of fluid being squeezed between the occluder and the guiding struts is accounted for by Reynold's equation. The effect of the fluid being squeezed between the occluder and the guiding strut was to reduce the velocity of the occluder tip at the instant of valve closure as well as dampen the fluttering of the occluder before coming to rest in the fully closed position. The squeeze film fluid pressure changed rapidly from a high positive value to a relatively large negative value in less than 1 msec. The results of this study may be extended for the analysis of cavitation inception, mechanical stresses on the formed elements and valve components as well as to estimate the endurance limits of the prosthetic valves.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.285-290
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• 1998

There are various reports on the fracture of mechanical heart valves implanted in human or animal, and they are pointed out that problems are induced by an erosion of disk surface, due to a cavitation effect. We have been investigating this mechanism using accelerated fatigue tester, and it was found that erosion was enhanced by a compliance effect in the test circuit. In this study, effects of compliance value and location on erosion were discussed, while disk closing velocity was measured by a high speed video camera. It was clarified that faster closing velocity was resulting in a enhancement of erosion on the disk surface.