• Journal of Chest Surgery
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• v.32 no.3
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• pp.255-261
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• 1999

Background: Atrial fibrillation is one of the most prevalent of all arrhythmias and in up to 79% of the patients with mitral valve disease. This study examined whether the atrial fibrillation that occur in patients with mitral valve operation could be eliminated by a concommitant maze operation without cryoablation. Material and Method: From May 1997 to April 1998, 14 patients with atrial fibrillation associated with mitral valve disease underwent Maze III operation without cryoablation. Preoperatively there were 6 men and 8 women with an average age of 46.2${\pm}$10.7 years. Eleven patients had mitral stenosis, and three had mitral insufficiency. The associated heart diseases were aortic valve disease in 4, tricuspid valve regurgitation in 1 and ASD in 2. Using transthoracic echocardiography, the mean left atrial diameters was 54.7${\pm}$5.3 mm and thrombi were found in the left atrium of 2 patients. Postoperatively the ratio between the peak speed of the early filling wave and that of the atrial contraction wave (A/E ratio) was determined from transmitral flow measurement. Operations were mitral valve replacement in 13 including 4 aortic valve replacements, 1 DeVega annuloplasty and 2 ASD closures. Maze III operation was performed in 1 patient. Result: Five patients (38%) had recurred atrial fibrillation, which was reversed with flecainide or amiodarone at the average time of postoperative 38.8${\pm}$23.5 days. Postoperative complications were postoperative transient junctional rhythm in 6, transient atrial fibrillation in 5, reoperation for bleeding in 3, postpericardiotomy syndrome(1), unilateral vocal cord palsy(1), postoperative psychosis(1), and myocardial infarction(1). Postoperatively A/E ratio was 0.43${\pm}$0.22 and A wave found in 9(64%) patients. 3 to 14 months postoperatively (average follow- up, 8.1 months), all of patients had normal sinus rhythm and 9(64%) patients had left atrial contraction and 11(79%) patients were not on a regimen of antiarrhythmic medication. Conclusion: We conclude that Maze III operation without cryoablation is an effective surgical treatment in atrial fibrillation associated with the mitral valve disease.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.346-352
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• 1998

Rheumatic valvulitis produces at least three distinct pathologic changes, the degree varying widely among the patients: fusion of the valve leaflets at the commissures; fusion and shortening of chordae tendinae: and fibrosis of the leaflets with subsequent stiffening, contraction and calcification. The most extensive changes usually are seen in patients with recurrent attacks of rheumatic fever. We studied on outcome of the surgical treatments of rheumatic valvular diseases that have been experienced for 12 years since 1982 at Pusan National University Hospital. The diagnoses were made by rheumatic fever history, echocardiographic findings, gross operative findings and microscopic findings. Total 502 patients were performed surgery for valvular heart diseases and 440 patients of rheumatic origin have bene analysed. There were more female than male patients as 1.3:1, and the mean age was 37.8 years old. 96.3% of them affected to the mitral valve, 19.8% to aortic valve, 16.3% affected to the tricuspid valve. Most of them underwent valve replacement, and valve repair was done in 3.9% of patients. There were 36 hospital deaths(8.2%) mainly from low cardiac output syndrome, and 15 late deaths equally due to embolism and hemorrhage. Follow up was 90.1% completed(2890 patient- year). Linealized rates of late complication events are follows : thromboembolism 1.3% per patient year; anticoagulant related hemorrhage 0.8% per patient year. Overall actuarial survival including hospital mortality was 92.7＋/-2.9% in 1 year, 88.0＋/-4.5% in 5 year, 82.3＋/-7.7% in 10 year. We conclude that the rheumatic disease is still the most frequent and the most important cause of heart valve disease. So more intensive study is needed in spite of the abrupt decreasing rate of rheumatic fever in U.S.A. and other industrial country.

• 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.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.278-283
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• 2003

This study was carried out to examine the nitrogen removal rate of a subsurface-flow treatment wetland system which was constructed on floodplain of the Kwangju River from May to June 2001. Its dimensions were 29m in length, 9m in width and 0.65m in depth. A bottom layer of 45cm in depth was filled with crushed granite with about $15{\sim}30\;mm$ in diameter and a middle layer of 10cm in depth had pea pebbles with about 10 mm in diameter. An upper layer of 5 cm in depth contained course sand. Reeds (Phragmites australis) were transplanted on the surface of the system. They were dug out of natural wetlands and stems were cut at about 40 cm height from their bottom ends. Water of the Kwangju River flowed into it via a pipe by gravity flow and its effluent was funneled back into the river. The height of reed stems was 44.2 cm in July 2001 and 75.3cm in September 2001. The number of stems was increased from $80\;stems/m^2$ in July 2001 to $136\;stems/m^2$ in September 2001. Volume and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Inflow and outflow averaged 40.0 and $39.2\;m^3/day$, respectively. Hydraulic detention time was about 1.5 days. Average nitrogen uptake by reeds was $69.31\;N\;mg/m^2/day$. Removal rate of $NO_3-N$, $NH_3-N$, T-N averaged 195.58, 53.65, and $628.44\;mg/m^2/day$, respectively. Changes of $NO_3-N$ and $NH_3-N$ abatement rates were closely related to those of wetland temperatures. The lower removal rate of nitrogen species compared with that of subsurface-flow wetlands operating in North America could be attributed to the initial stage of the system and inclusion of two cold months into the six-month monitoring period. Increase of standing density of reeds within a few years will develop both root zones suitable for the nitrification of ammonia and surface layer substrates beneficial to the denitrification of nitrates into nitrogen gases, which may lead to increment in the nitrogen retention rate.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.387-391
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• 2002

Background: Postoperative morbidity and mortality in destroyed lung are relatively high. We tried to identify the prognostic factors affecting postoperative morbidity and mortality in destroyed lung through a retrospective study. Material and method: The retrospective study was undertaken in 112 patients who had undergone pneumonectomy or pleuropneumonectomy for destroyed lung at Severance Hospital from 1970 to 2000. We analyzed the correlation between postoperative morbidity and mortality and etiology, duration of disease, preoperative FEV1, presence or absence of peroperative empyema, operation timing, the side of operation, duration of operation, and operation type. Result: There were 55 men and 57 women, aged 20 to 81 years (mean 44 years). Etiologic diseases were tuberculosis in 86 patients(76.8%) including tuberculos empyema in 20 and tuberculous bronchiectasis in 4, pyogenic empyema in 12(10,7%), bronchiectasis in 12(10.7%), and lung abscess in 2(1.8%). Postoperative morbidity were 25%(n=28) and postoperative mortality was 6%(n=7). The presence of preoperative empyema(p=0.016), pleuropneumonectomy(p=0.037) and preoperative FEV1 of less than 1.75 L(P=0.048) significantly increased the postoperative morbidity, If operation time was less than 300min, postoperative morbidity(p=0.002) and mortality(p=0.03) were significantly low. Conclusion: Postoperative morbidity and mortality in destroyed lung were acceptable. Postoperative morbidity and mortality were significantly low when operation time was less than 300 min. Preoperative existence of empyema, pleuropneumonectomy and preoperative FEV1 of less than 1.75 L significantly increased postoperative morbidity.