• Korean Circulation Journal
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• v.53 no.11
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• pp.744-755
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• 2023

Background and Objectives: Aortic valve replacement (AVR) is considered a class I indication for symptomatic severe aortic stenosis (AS). However, there is little evidence regarding the potential benefits of early AVR in symptomatic patients diagnosed with normal-flow, low-gradient (NFLG) severe AS. Methods: Two-hundred eighty-one patients diagnosed with symptomatic NFLG severe AS (stroke volume index ≥35 mL/m², mean transaortic pressure gradient <40 mmHg, peak transaortic velocity <4 m/s, and aortic valve area <1.0 cm²) between January 2010 and December 2020 were included in this retrospective study. After performing 1:1 propensity score matching, 121 patients aged 75.1±9.8 years (including 63 women) who underwent early AVR within 3 months after index echocardiography, were compared with 121 patients who received conservative care. The primary outcome was a composite of all-cause death and heart failure (HF) hospitalization. Results: During a median follow-up of 21.9 months, 48 primary outcomes (18 in the early AVR group and 30 in the conservative care group) occurred. The early AVR group demonstrated a significantly lower incidence of primary outcomes (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.29-0.93; p=0.028); specifically, there was no significant difference in all-cause death (HR, 0.51; 95% CI, 0.23-1.16; p=0.110), although the early AVR group showed a significantly lower incidence of hospitalization for HF (HR, 0.43; 95% CI, 0.19-0.95, p=0.037). Subgroup analyses supported the main findings. Conclusions: An early AVR strategy may be beneficial in reducing the risk of a composite outcome of death or hospitalization for HF in symptomatic patients with NFLG severe AS. Future randomized studies are required to validate and confirm our findings.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.679-683
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• 1998

From June 1995 to May 1997, we have implanted 52 Sorin Bicarbon mechanical valves in 41 patients. They were 16 men and 25 women, and their mean age was 47.4${\pm}$14.8(range; 18∼74 y.o.). 35(27 mm∼31 mm) were in mitral position, 15(19 mm∼25 mm) in aortic position, and 2(31 mm) in tricuspid position. 3 CABGs and a tumor excision were taken concomittantly. 35 patients were primary operation, and 6 were re-do operations. By intraoperative transesophageal doppler echocardiography, transvalvular peak/mean pressure gradient was 6.1${\pm}$2.7/2.4${\pm}$1.4 mmHg in mitral position and 27.6/10.7 mmHg in aortic position. The effective valve opening area in mitral position was 3.2${\pm}$0.6 cm2. Follow-up was total 508.6 patient-months, and mean follw-up was 12.7${\pm}$9.2 months. NYHA class was improved from 2.6${\pm}$0.6 to 1.2${\pm}$0.3 in average postoperatively. During that period, there was no operative death. 2 late non-valve related deaths were occurred. One was died of COPD, and the other was possible acute myocardial infarction. Among 7 postoperative complications, one valve related complication(minimal paravalvular leakage) was noticed. In conclusion, Sorin Bicarbon mechanical valve is believed one of the safe choice in clinical settings. It showed excellent hemodynamic and mechanical functions, and very low postoperative valve related complications in short term clinical experience.

• Journal of Chest Surgery
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• v.35 no.1
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• pp.36-42
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• 2002

Background: To evaluate the efficiency of surgical treatment in patients with cardiac valvular and arterial involvement of Behcet's syndrome. Material and Method: 12 patients underwent surgical treatment due to the valvular heart diseases and the various arterial diseases associated with Behest's syndrome over 7 years; 6 with valvular heart disease, 1 with annuloaortic ectasia, 1 with ascending aortic aneurysm, 4 with pseudoaneurysms in abdominal aorta(n=2), carotid artery(n=1), and popliteal artery(n=1). All 12 patients had received valvular replacement(n=6) and the artificial(n=5) or autologous(n=1) graft interposition. We followed the results of these surgical treatments. Result: Operations were technically successful in all 12 patients and peri-operative complication was not demonstrated. However, 10 patients had recurrences; 6 with valvular dehiscence, 3 with pseudoaneurysm at anastostomosis site, and 1 with aorto-duodenal fistula. The duration of recurrence was 1 to 55 months(mean: 15.7$\pm$ 16.2 months). 7 patients underwent the second operation and among them, 4 patients showed repeated recurrences. Overall, 5 patients died 2 to 25 months after the operation(mean: 13.6 months), because of the bleeding at the anastomosis site Five patients did not present recurrence after the first(n=2) or the second operation(n=3) and their follow up duration was 5 to 60 months(mean: 45.8$\pm$41.7 months). Five patients received immune-suppressive therapy after the first(n=2) and second operation(n=3). Three did not shown recurrence for the 13, 29 and 33 months. Conclusion: Post-operative prognosis of arterial manifestation of Behcet's syndrome was not encouraging and if possible, other treatment strategy should be considered.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.12-24
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• 2008

Background: It is currently thought that tissue valve degeneration is related to an animal's immune response, which is mainly due to cell surface ${\alpha}$-Gal epitopes. Cell surface ${\alpha}$-Gal epitopes are known to be degraded by the enzyme called green coffee bean ${\alpha}$-Galactosidase. It is also well known that ${\alpha}$-Gal epitopes are immunologically stained by Griffonia Simplicifolia isolectin type B4. We know that many commercially available tissue valves are made of aortic valves and pericardial tissue of pig. So, we investigated whether ${\alpha}$-Gal epitopes of the aortic valve and pericardial tissue of a pig can be removed by green coffee bean ${\alpha}$-Galactosidase, and we did so by comparing immunologic staining of the tissues before and after the enzyme treatment. Material and method: After treating fresh porcine aortic valve and pericardial tissue with green coffee bean ${\alpha}$-Galactosidase at concentrations of 0.5 unit/mL, 1.0 unit/mL, 2.0 unit/mL, respectively, under the condition of pH 6.5, temperature. $4^{\circ}C$ and 24 hours of incubation, each sample was stained with Griffonia Simplicifolia isolectin type B4 immunpfluorescent labeling. We then examined whether the ${\alpha}$-Gal epitopes were reduced or abolished in each consecutive. concentration of green coffee bean ${\alpha}$-Galactosidase by comparing the degree of the Griffonia Simplicifolia isolectin B4 staining in each sample. Result: In the pig aortic valve tissue, a 1.0 unit/mL concentration of green coffee bean ${\alpha}$-Galactosidase at pH 6.5, $4^{\circ}C$ and reaction for 24 hours was enough for complete removal of ${\alpha}$-Gal epitopes from the cell sur face on the immunostaining with Griffonia Simplicifolia isolectin B4. On the other hand, more ${\alpha}$-Gal epitopes were present in the pig pericardial tissue on Griffonia Simplicifolia isolectin B4 staining before the enzyme treatment, and 1.0 unit/mL of galactosidase was not sufficient for complete removal of ${\alpha}$-Gal from the tissue. 2.0 units/mL of green coffee bean ${\alpha}$-Galactosidase was needed to completely remove the ${\alpha}$-Gal epitopes from the pericardial tissue on immunostaining. Conclusion: The ${\alpha}$-Gal epitopes of the pig's aortic valve and pericardial tissue were successfully stained with Griffonia Simplicifolia isolectin B4. We could remove nearly all the ${\alpha}$-Gal epitopes using green coffee bean ${\alpha}$-Galactosidase at the concentration of 1.0 unit/mL in the aortic valve. Of pig, and 2.0 unit/mL was need to nearly completely remove all the ${\alpha}$-Gal epitopes in the pericardial tissue of pig under the condition of pH 6.5, $4^{\circ}C$ and 24 hours of reaction time. In the near future, removal of ${\alpha}$-Gal epitapes in the pig's aortic valve and pericardial tissue will become a powerful tool for the improvement of the tissue valve durability. It needs to be determined if ${\alpha}$-galactosidase treated pig tissue is immune to human anti-Gal antibody or anit-Gal mooclonal antibodies.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.602-613
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• 2010

Background: As life expectancy has been increased, the cardiac valve disease has been increased. In past, mechanical valve for valve replacement surgery was used widely, but it has many weaknesses, such as hemorrhage, teratogenic effect caused by warfarin, acute mechanical failure, taking warfarin during life, etc. So, the tissue valve is used widely and researches for durability of tissue valve are in progress. Tissue valves being used are all imported in Korea, and there is a lack of information on its geometry and design. So, we studied the geometry of porcine aortic and pulmonary valve, and tried to suggest theoretical basis for making the aortic and pulmonary valve. Material and Method: We harvested aortic and pulmonary valves of 25 pigs and measured the geometry of valve at fresh and glutaraldehyde (GA) fixed state. In each group, we measured the diameter of the base, diameter of commissure, valve height, commissural height, etc. Also, for making implantable porcine and bovine pericardial valve, we designed the valve stent form, thickness, height, and leaflet size, form, thickness by different size of valve. Result: The aortic and pulmonary valve geometry and ratio were measured in each group. The right coronary cusp of aortic valve and right facing cusp of pulmonary valve was bigger than other cusps and non coronary cusp was smaller than others (RCC: NCC : LCC=1 : 0.88 : 1). Valve height was correlated to the leaflet size. We designed the outer diameter of stented porcine aortic valve from 19 mm to 33 mm and designed stent height and width, using previous measured ratio of each structure, stent thickness, working thickness (for making valve). Also, we designed the size of stent and form for stented bovine pericardial valve, considering diameter of valve, leaflet length, height and leaflet minimum coaptation area. Conclusion: By measuring of 25 pig's aortic and pulmonary valve geometry and ratio, we can make theoretical basis for making implantable stented porcine valve and bovine pericardial valve in various size. After making implantable valve using these data, it is necessary to do in vivo and in vitro researches, furthermore.

• Korean Journal of Clinical Pharmacy
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• v.23 no.2
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• pp.151-157
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• 2013

Purpose: Warfarin is the most widely used anticoagulant drug for preventing cardiovascular diseases after ischemic stroke and thromboembolism related to atrial fibrillation, artificial heart valves, deep vein thrombosis, and pulmonary embolism. Warfarin is commonly used in combination with other drugs such as diuretics in order to treat the comorbidity. Although several warfarin-diuretics interactions have been reported, the results are conflicting. Therefore, the initial aim of this study was to identify the effects of diuretics on the warfarin response in patients with atrial fibrillation. Methods: One hundred forty six patients with atrial fibrillation who were on anticoagulation therapy with warfarin and maintained INR levels of 2-3 for three consecutive times were followed up, retrospectively. Stable warfarin doses and INR per stable warfarin dose were compared according to age, gender, comorbidity, and concurrent medication. The stable warfarin dose was defined as the maintenance dose of warfarin of the measured patient whose INR was within the target INR range more than 3 times consecutively. Results: The differences of stable warfarin doses in patients with ($3.22{\pm}1.21$ mg/day) and without ($3.58{\pm}1.14$ mg/day) diuretics were marginally significant (P=0.069). On the other hand, stable warfarin doses were $2.97{\pm}1.10$ mg/day in patients with thiazide (n=36) and $3.58{\pm}1.14$ mg/day in patients without diuretics (n=82), which was statistically significant (p=0.009). INR values per stable warfarin dose in patients with diuretics and thiazide were $0.84{\pm}0.31$ and $0.90{\pm}0.34$, respectively, which were statistically different from those without diuretics ($0.72{\pm}0.21$, P=0.010 and P=0.006, respectively). Age, gender, and concurrent use of thiazide diuretics were found to have significant influence on the warfarin response from multivariate analysis. Conclusion: Our study showed that the concurrent use of thiazide diuretics could increase the response of warfarin in patient with atrial fibrillation. Therefore, clinicians should be aware that warfarin dose needs to be adjusted when it is used with thiazide diuretics concomitantly.

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.439-448
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• 2001

This paper considers the acoustical characteristics of the closing click sounds of the mechanical valves employed in an implantable biventricular assist device (BYAD) and their re1evance to the Physical states of the valved. Bj rk Shiley Convexo Concave tilting disk valve was chosen for the study and acoustic measurement was made for the BYAD operated in a mock circulatory system as well as implanted in an animal (sheep). In the BYAD operated in the mock circulatory system. three different states of the valve were examined, ie. normal. mechanically damaged. pseudo-thrombus attached. Microphone measurement for the BVAD implanted in the animal was carried out for five days at a regular time interval from one day after implantation. Characteristic spectrum of the sound from the valve was estimated using Multiple Signal Classification (MUSIC) in which the optimal order was determined according to Bayesian Information Criterion (BIC) . It was observed that the mechanical damage of the valve resulted in changes of the structure of the acoustic spectrum. In contrast. the thrombus formed on the valve did not change much the basic structure of the spectrum but brought about altering the spectral Peak frequencies and energies. Maximum spectral Peak (MSP) with the greatest energy was seen at 2 kHz for the normal valve and it was shifted to 3 kHz for the calve attaching the Pseudo-thrombus. Unlike the normal valve, strong spectral Peak appeared around 7 kHz in the sound from the valve mechanically damaged. In the case of the BYAD implanted in the animal. as the thrombus grew, acoustic energy was reduced relatively more in the low frequency components (〈 2 kHz) and the frequencies of the 1st, 2nd and 3rd MSP were increased little. The thrombus formation would result in reduction in both the variability of the 1st, 2nd and 3rd MSP and the value of the BIC optimal order.

• Journal of Chest Surgery
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• v.33 no.5
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• pp.391-397
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• 2000

Background: Cardiac involvement of Behcets disease is very rate, however, the prognosis of Behcet disease depends on cardiovascular complications. In this article, we described surgical treatment of aortic insufficiency with Behcets disease. Material and Method: From March 1986 to February 1998, we operated on 10 patients of aortic insufficiency with Behcets disease. Male to female ratio was 8 to 2, and age ranged from 21 to 40 years(mean 32.8 years). There were 8 patients with evidence of Behcets disease and another 2 patients had some suspicious findings of Behcets disease(i.e., prosthetic value dehiscence, hypertrophied aortic wall). Adequate preoperative medical treatment for Behcets disease was done in 3 patients. Result: We performed 24 open heart surgeries in 10 patients. Redo value replacements using prosthetic valves were done in 4 patients. Among them, 2 patients were operated on for a second redo valve replacement and one of them operated on for a 4th and 5th operation because of recurrent paravalvular leakage. These 4 patients expired. 1 patient who had undergons tissue value replacement is alive. 1 patient who underwent Cabrol operation expired dut to rupture of graft anastomosis site. We used homografts in 3 patients. In 2 of them, we performed aortic root replacement and subcoronary valve replacement in another patient. The patient who underwent subcoronary valve insertion had remnant aortic insufficiency, so we are closely observing him. We also performed Ross operation in a 24 year old female who suffered severs aortic insufficiency and endocarditis after aortic valvuloplasty. 5 patients are alive and mean follow up duration is 49.0 months. Among them, we used homografts or sutografts in 4 patients. We could observe excellent clinical results in the patients who underwent aortic root replacement using homograft and they were treated medically for Behcets disease. Conclusion: We concluded that adequate preporative diagnosis, clinical suspicion, and periopertive medical treatment for Behcets disease are very important for the result of surgical management of aortic insufficiency with Behcets disease. The use of homograft or autograft was helpful for the healing of anastomosis site and we should carefully observe the long term follow up results.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.270-274
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• 1997

In recent years, the use of allograft conduits in repair of congenital cardiac disease is widely accepted. However, the supply of homograft. is currently limiting their increased clinical application, especially small cryopreserved homografts for use in neonates and inf'ants. We used a technique to surgically reduce the size of the more readily available large-diameter allografts, making them suitable for right ventricular outflow tract reconstruction in small infants and children. From December 1994 to March 1996, a total of 11 patients ranging in age from 10 months to 6 years (mean age, 27.3 months) and ranging in weight from 5.6 to 18.5 kg (mean 11.5 kg) underwent reconstruction of the right ventricular outflow tract using this surgical technique (pulmo ary atresia with ventricular septal defect, 9 cases ; tetralogy of Falloff, 2 cases). The diameter after downsizing ranged from 14 to 19 mm with a mean of 16.8 mm. There was one operative death due to rupture of the infected homograft. Evaluation of these patients between 2 and 15 months (mean 6.9 months) after homograft implantation reveals excellent clinical and echocardiographic results. There were no significant homograft insufficiency and RVOT obstructions. Although a longer follow-up is certainly required to evaluate the long term fate of the surgically modified bicuspid homografts, we believe that this technique may represent a valuable therapeutic alternative, at least in the short term, to the use of synthetic grafts when an appropriately sized homograft is not available.

• Journal of Chest Surgery
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• v.29 no.4
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• pp.444-448
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• 1996

Hemolytic anemia due to tiny prosthetic paravalvular leakage is one of a complication of prosthetic valve replacement. Mild Hemolysls usually occurs after aortic valve replacement with mechanical valve but rarely occurs in mitral valve position especially in case of tissue valve. Cardiac valves fabricated from biologic material are associated with a reduced incidence of hemolytic anemia. Hemolysis was reported in patients with an lonescu-Shiley bovine pericardial xenograft prosthesis in the aortic position but not in the mitral site. A 41-year-old female patient was admitted due to sudden development dark colored urine. About 10 years ago the patient was underwent MVR (Mitral Valve Re lacement) with fTmm lonescu-Shiley valve due to MR (Mitral regurgitation). Echocardiographic examination showed mild degree of mitral regurgitation with valvular thickening. However, there was no definitive evidence of paravalvular leakage. The peripheral blood smear showed nomochromic normocytic anemia, but the hematologic and urinary examination revealed severe hemolytic evidence. Mitral valve replacement with St. Jude Medical valve (27mm) was done and intraoperatively, a tiny paravalvular leakage was found which was regarded as the point of hemolysis. The hemolytic evidence completely disappeared. We are reporting a case of severe hemolytic anemia due to tiny prosthetic paravalvular leakage with a review of the literature.