• Journal of Chest Surgery
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• v.43 no.4
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• pp.375-380
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• 2010

Background: Primary cardiac tumors are extremely rare. The most common type are benign myxomas, and these are almost completely curable with early surgery. Malignant tumors, however, such as sarcomas, are difficult to remove surgically, and their prognosis is known to be poor. In this study, data on patients who had undergone surgical treatment of cardiac tumor in the authors' hospital were collected and analyzed. Material and Method: The subjects included 28 patients who had undergone surgical treatment of cardiac tumor from August 1993 to December 2008. Their medical records were reviewed and retrospectively analyzed. Result: The patients were aged from 20 to 76 years (mean age: $54.2{\pm}15.6$), and 11 were male (39%) and 17 female (61%). Fifteen of them (54%) underwent emergency surgery to improve heart failure symptoms. The most common preoperative symptom was dyspnea (15 cases, 54%). Preoperative echocardiography was performed on all the patients. The average size of the tumor as measured during the operation was $7.0{\pm}6.9cm$ (the average length of the long axis was 2∼40 cm), and the sites of tumor attachment were the interatrial septum (18 cases, 64%), the left atrium (9 cases, 32%), the mitral valve annulus (2 cases, 7%), and the left ventricle (2 cases, 7%). The operation was performed with an incision through both atria in all the patients, and a complete excision was made in 25 cases (89%). According to the biopsy results, there were 4 cases of sarcoma (14%), 1 case of lipoma (4%), and 23 cases of myxoma (82%). The three cases in which the tumors were not completely excised were sarcomas. No operative deaths occurred after the operations. Outpatient follow-up was possible for 24 cases (86%), with a mean follow-up period of $46.8{\pm}42.7$ months. Late death occurred in 3 of the 24 patients; each of these patients had sarcomas. Of these patients, the first had undergone two repeat surgeries, the second had metastatic sites removed, and the last had only chemotherapy. The average recurrence time was $12.7{\pm}10.8$ months, and the average metastasis time was $20.5{\pm}16.8$ months. Conclusion: Most cardiac tumors are benign myxomas. In principle, they should be surgically treated because they can create risks such as embolism, and can be radically treated when surgically removed. In most cases, however, malignant sarcomas are already considerably advanced with severe infiltration into the neighboring tissues at the time of diagnosis. The surgical removal of malignant sarcomas is known to be difficult because of the advanced stage and degree of infiltration. We suggest that excision of the removable portion of the tumor sites to alleviate symptoms such as heart failure can improve quality of life.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1081-1089
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• 1996

Pulmonary atresia with intact ventricular septum has continued to have a high surgical mortality and morbidity. This mAy attribute to the non-uniformity of the anomaly. We reviewed a total of 34 infants with pulmonary atresla and intact ventricular septum managed in this hospital between 1987 and 1995. Mean age and body weight were 57.2 (range, 3-208) days and 4.1 (range, B.3∼6.8) kg. The preoperative Z-value of the diameter of the tricuspid valve was less than -2 in 85.2% of patients and less than -4 in 33. 3% . It is well correlated w th right ventricular cavity size (n=27. r10.68, p< 0.05). Coronary artery-right ventricular fistulas were identified in 3 patients, and right ventricular dependency was suspected in 1 Over All hospital mortality was 23.5%(8/34), although it decreased to 16.6%(4124) in 1990s. Subsequent procedures were performed in 6 patients between 3 days and 58 months after Initial palliation : one bidirectional cavopulmonary shunt and 1 Fontan operation after systemic-pulmonary shunt, 3 transannular patch + atrial septal defect closure and 1 additional systemic-pulmonary shunt after polmonary valvectomy or valvotomy. Changes of Z-values of the diameter of tricuspid valve have been followed up in 11 patients between 1 and 66 months postoperatively. Z-values were increased In 5 out of 8 transannular right ventriculAr outflow tract enlargement group and in 1 out of 3 pulmonary valvectomy or valvotomy group. Our data suggest that tailoring a treatment to right ventricular cavity size and coronary anom lies may improve the surgical outcome. A Z-value of the tricuspid valve diameter could be used.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.179-200
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• 1996

The intrinsic instabilities of fluid flow occurred in the melt of the Czochralski crystal growth system Czochralski method, asymmetric flow patterns and temperature profiles in the melt have been studied by many researchers. The idea that the non-symmetric structure of the growing equipment is responsible for the asymmetric profiles is usually accepted at the first time. However further researches revealed that some intrinsic instabilities not related to the non-symmetric equipment structure in the melt could also appear. Ristorcelli had pointed out that there are many possible causes of instabilities in the melt. The instabilities appears because of the coupling effects of fluid flow and temperature profiles in the melt. Among the instabilities, the B nard type instabilities with no or low crucible rotation rates are analyzed by the visualizing experiments using X-ray radiography and the 3-D numerical simulation in this study. The velocity profiles in the Silicon melt at different crucible rotation rates were measured using X-ray radiography method using tungsten tracers in the melt. The results showed that there exits two types of fluid flow mode. One is axisymmetric flow, the other is asymmetric flow. In the axisymmetric flow, the trajectory of the tracers show torus pattern. However, more exact measurement of the axisymmetrc case shows that this flow field has small non-axisymmetric components of the velocity. When fluid flow is asymmetric, the tracers show random motion from the fixed view point. On the other hand, when the observer rotates to the same velocity of the crucible, the trajectory of the tracer show a rotating motion, the center of the motion is not same the center of the melt. The temperature of a point in the melt were measured using thermocouples with different rotating rates. Measured temperatures oscillated. Such kind of oscillations are also measured by the other researchers. The behavior of temperature oscillations were quite different between at low rotations and at high rotations. Above experimental results means that the fluid flow and temperature profiles in the melt is not symmetric, and then the mode of the asymmetric is changed when rotation rates are changed. To compare with these experimental results, the fluid flow and temperature profiles at no rotation and 8 rpm of crucible rotation rates on the same size of crucible is calculated using a 3-dimensional numerical simulation. A finite different method is adopted for this simulation. 50×30×30 grids are used. The numerical simulation also showed that the velocity and flow profiles are changed when rotation rates change. Futhermore, the flow patterns and temperature profiles of both cases are not axisymmetric even though axisymmetric boundary conditions are used. Several cells appear at no rotation. The cells are formed by the unstable vertical temperature profiles (upper region is colder than lower part) beneath the free surface of the melt. When the temperature profile is combined with density difference (Rayleigh-B nard instability) or surface tension difference (Marangoni-B nard instability) on temperature, cell structures are naturally formed. Both sources of instabilities are coupled to the cell structures in the melt of the Czochralski process. With high rotation rates, the shape of the fluid field is changed to another type of asymmetric profile. Because of the velocity profile, isothermal lines on the plane vertical to the centerline change to elliptic. When the velocity profiles are plotted at the rotating view point, two vortices appear at the both sides of centerline. These vortices seem to be the main reason of the tracer behavior shown in the asymmetric velocity experiment. This profile is quite similar to the profiles created by the baroclinic instability on the rotating annulus. The temperature profiles obtained from the numerical calculations and Fourier transforms of it are quite similar to the results of the experiment. bove esults intend that at least two types of intrinsic instabilities can occur in the melt of Czochralski growing systems. Because the instabilities cause temperature fluctuations in the melt and near the crystal-melt interface, some defects may be generated by them. When the crucible size becomes large, the intensity of the instabilities should increase. Therefore, to produce large single crystals with good quality, the behavior of the intrinsic instabilities in the melt as well as the effects of the instabilities on the defects in the ingot should be studied. As one of the cause of the defects in the large diameter Silicon single crystal grown by the

• Clinical and Experimental Pediatrics
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• v.53 no.1
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• pp.72-79
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• 2010

Purpose: Left ventricular (LV) hypertrophy and impaired diastolic function may occur early in systemic hypertension. Diastolic dysfunction is associated with increased cardiovascular risk. Tissue Doppler imaging (TDI)-derived tissue velocity and strain rate are new parameters for assessing diastolic dysfunction. The aim of this study is to determine whether TDI and strain rate imaging (SRI) would improve the ability to recognize early impaired diastolic and systolic functions compared with conventional echocardiography in hypertensive adolescents. Methods: We included 38 hypertensive patients with systolic blood pressure above 140 mmHg or diastolic blood pressure above 90 mmHg. Ejection fraction and myocardial performance index (MPI) were estimated by conventional echocardiography. Peak systolic myocardial velocity, early diastolic myocardial velocity (Em), and peak late diastolic myocardial velocity (Am) were obtained by using TDI and SRI. Results: In the hypertensive group, interventricular septal thickness was significantly increased on M-mode echocardiography. Em/Am was significantly decreased at the mitral valve annulus. Among hypertensive subjects, the E strain rate at basal, mid, and apex was significantly decreased. Systolic strain was significantly decreased at the septum in the hypertensive group. Conclusion: Strain rate might be a useful new parameter for the quantification of both regional and global LV functions and could be used in long-term follow up in hypertensive patients. Early identification by SRI of subjects at risk for hypertensive and ventricular dysfunction may help to stratify risk and guide therapy. Further studies, including serial assessment of LV structure and function in a larger number of adolescents with hypertension, is necessary.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.350-355
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• 2002

Background: Most of pulmonary regurgitation with or without stenosis appears to be well tolerated early after the repair of pulmonary outflow tract. However, it may result in symptomatic right ventricular dilatation, dysfunction and arrhythmias over a long period of time. We studied the early outcome of pulmonary valve replacement with tissue valves for patients with the above clinical features. Material and Method: Sixteen consecutive patients who underwent pulmonary valve replacement from September 1999 to February 2002 were reviewed(9 males and 7 females). The initial diagnoses included tetralogy of Fallot(n=11), and other congenital heart anomalies with pulmonary outflow obstruction(n=5). Carpentier-Edwards PERIMOUNT Pericardial Bioprostheses and Hancock porcine valves were used. The posterior two thirds of the bioprosthetic rim was placed on the native pulmonary valve annulus and the anterior one third was covered with a bovine pericardial patch. Preoperative pulmonary regurgitation was greater than moderate degree in 13 patients. Three patients had severe pulmonary stenosis. Tricuspid regurgitation was present in 12 patients. Result: Follow-up was complete with a mean duration of 15.8 $\pm$ 8.5months. There was no operative mortality. Cardiothoracic ratio was decreased from 66.0 $\pm$ 6.5% to 57.6 $\pm$ 4.5%(n=16, p=0.001). All patients remained in NYHA class I at the most recent follow-up (n=16, p=0.016). Pulmonary regurgitation was mild or absent in all patients. Tricuspid regurgitation was less than trivial in all patients. Conclusion: In this study we demonstrated that early pulmonary valve replacement for the residual pulmonary regurgitation with or without right ventricular dysfunction was a reasonal option. This technique led to reduce the heart size, decrease pulmonary regurgitation and tricuspid regurgitation as well as to improve the patients'functional status. However, a long term outcome should be cautiously investigated.

• Journal of Chest Surgery
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• v.40 no.4 s.273
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• pp.288-291
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• 2007

Background: Myxoma makes up close to 50% of adult primary cardiac tumors, and this mainly occurs in the left atrium, and rarely in the right atrium or ventricle. The patients clinically present with symptoms of hemodynamic obstruction, embolization or constitutional changes. Diagnosis is currently established most appropriately with 2-D echocardiography. Surgical resection of myxoma is a safe and effective treatment, Material and Method: We reviewed our clinical experience in the diagnosis and management of 57 cases of cardiac myxoma that were seen over a 20-year period from July 1984 to July 2004. Result: The mean age of the patients was $53.5{\pm}14.0$ years (range: 12 to 76 years). There were 38 (67%) females and 19 (33%) males. The preoperative symptoms included dyspnea on exertion in 27 patients, palpitation in 4, chest pain in 9 and syncopal episode in 4. The diagnosis was made by echocardiography alone in 51, and by combination of echocardiography, CT and angiography in 6. The tumor attachment sites were the interatrial septum in 50, the mital valve annulus in 3 and the left atrial wall in cases, The tumor was excised successfully via biatriotomy in 33 (58%), left atriotomy in 15 (26%), the septal approach via right atriotomy in 3, Inverted T incision in 3 and the extended septal approach in 3. The follow-up time ranged from 1 to 229 months (mean follow-up: $84.0{\pm}71.3$ months). There were no early and late deaths and no recurrence during the follow-up period except for follow-up loss in 5 patients. Conclusion: It's concluded that excision of cardiac myxoma is curative and the long-term survival is excellent. Immediate surgical treatment was indicated because of the high risk of embolization or of sudden cardiac death. Radical tumor excision may prevent recurrences.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.216-222
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• 2008

Background: Prosthetic annuloplasty rings are used for the reconstruction of the mitral valve annulus. However, there is controversy over the best ring to use for reconstruction. In this study, we evaluated the long term result of using a Teflon felt strip as an alternative to commercial rings. Material and Method: From 1996 to 2007, we enrolled 47 patients with pure mitral regurgitation greater than grade III. All patients had an ejection fraction of 40% or more. Patients with congenital heart disease or other valvular heart disease were excluded from this study. They were divided into two groups; the commercial ring group (Group CR) and the Teflon felt ring group (Group TF). Result: There was no mortality. The postoperative echocardiography showed no significant change in the overall ejection fraction (from $58.0{\pm}11.2%\;to\;42.8{\pm}8.4%$). There were no significant differences between the two groups with regard to morbidity, the reoperation rate and recurrence of mitral regurgitation greater than grade II. Conclusion: The long term results from this study showed that posterior mitral annuloplasty using Teflon felt had similar results compared to annuloplasty using commercial rings.

• Journal of Chest Surgery
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• v.29 no.12
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• pp.1329-1336
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• 1996

From January, 1994 to January. 1996, mitral valve replacement was performed in 27 patients. Among these, 17 patients underwent mitral valve replacement(MVR) with preservation of the annulo-papillary continuity(PAPCMVR) (-Group I), and 10 patients underwent conventional methods of excision of all the chordae(Group II). The operative technique for PAPCM VR consists of the division of the anterior leaflet into anterior and posterior segments, shifting and reattachment of the divided segments to the mitral ring of the respective commissural areas. This retrospective study has been designed to evalute the postoperative left ventricular function in the two groups. In the group 1, LVEF(Left Vnetricular Ejection Fraction : %) was 52 $\pm$ 3 preoperatively And 50$\pm$3 postoperatively, LVESI Vent icular End Systolic Volume Index/mL/m2) wIns 59 :6 and 51 $\pm$ 7, LVEDI Ventricular End Diastolic Volume Index/mL/m2) was 124$\pm$ 11 and 91 :8. In the group II, LVEF was 56$\pm$1 and 47:), LVESVI 62$\pm$12 and 61$\pm$15, LVEDVI 133$\pm$27 and 104$\pm$17. : the variation of the LVEF in these two group was statistically different(p(0.05). A comparison of left ventricular function data between Group I(n: 17) and Group II(n: 10) revealed better results in echocardiographic LVEF(p<0.05), LVEDVI(p<0.01) in the former group. The mean functional class(UYHA) was 2.6 preoperative and improved to 1.0 postoperatively In group 1, and 2.8 and to 1.0 in group II. We conclude that maintenance of continuity between the mitral annulus and papillary muscles is expected to have a beneficial effect on postoperative left ventricular performance.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.703-709
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• 2008

Background: Diagnosis and treatment are often successful in the setting of cardiac myxomas. However, cardiac myxomas can lead to catastrophic complications, due to intracardiac obstruction and embolism preoperatively, and can recur postoperatively. Material and Method: We retrospectively reviewed the clinical characteristics, surgical treatment, and recurrence data of 85 patients who underwent cardiac myxoma surgery at Asan Medical Center between November 1994 and June 2007. We analyzed the morphologic characteristics of 58 patients with left atrial myxomas and determined the development of functional mitral valve stenosis and systemic embolism through reviewing the results of preoperative echo-cardiograms to find potential preoperative risk factors. Result: Twenty-seven (31.8%) patients were men, and 58 (68.2%) were women. The mean patient age was $54.5{\pm}14.3$ years. Preoperative symptoms included obstructive symptoms in 41 (48.2%) patients, signs of embolism in 19 (22.4%), constitutional symptoms in 8 (9.4%), and no symptoms in 19 (20.0%). Among the 58 patients with left atrial myxomas, the mean maximal tumor diameter was $4.3{\pm}1.8$ (range $1.1{\sim}8\;cm$)cm. Twenty-six (44.8%) patients had a prolapsing type, defined as a tumor mobile enough to move down. to the mitral. annular plane during diastole, and 32 (55.2%) had villous type, defined as a tumor consisting of multiple fine villous extensions on the surface. Twelve (20.7%) patients had severe functional mitral valve stenosis, and 15 (25.9%) had systemic embolism preoperatively. The incidence of severe functional mitral valve stenosis was significantly higher in patients with the prolapsing type than in those with the non-prolapsing type (p=0.001). The mean maximal tumor diameter in patients with severe functional mitral valve stenosis was $5.1{\pm}1.0\;cm$, significantly larger than that seen in patients without severe functional mitral valve stenosis (p=0.041). The incidence of systemic embolism was significantly higher in patients with the villous type than in those with the smooth type (p=0.006). Postoperative complications were noted in 6 (7.1%) patients, and early mortality was noted in 1 (1.2%). The mean postoperative follow-up duration was $36.2{\pm}37.5$ months, with recurrence reported in 2(2.4%) patients during the follow-up period. The disease free interval were 48, 12 months, respectively. Conclusion: Surgical treatment for cardiac myxomas was performed safely, and long-term prognosis was good. In patients with left atrial myxoma, close attention should be maintained and surgery should be performed promptly in those of prolapsing type, those with large maximal diameter in order to prevent severe functional mitral valve stenosis, and those of villous type in order to prevent systemic embolism. Echocardiography should be followed serially in order to detect recurrence.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.17.2-19
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• 1982

The sinus tympani is subject to great variability in the size, shape and posterior extent. A heavy compact bony zone, especially in the posterior portion and the narrow space between the facial nerve and posterior semicircular canal are the limitation of surgical approach. The facial recess should be opened, creating a wide connection between the mesotympanum and mastoid in the Intact canal wall tympanoplasty with mastoidectomy. The surgically created limits of the facial recess are the facial nerve medially, the chorda tympani laterally and the bone adjacent to the incus superiorly. Using adult Korean's thirty-five temporal bones, the authors measured the osteologic reslationship in the posterior tympanum, especially sinus tympani and facial recess. The result was as followed. 1. The average distance from the anterior end of the pyramidal eminence. 1) to the edge of the sinus tympani directly posterior was 2.54(1.05-5.40)mm. 2) to the maximum posterior extent was 3.22(1.25-7.45)mm. 3) to the maximum cephaled extent was 0.67 (0.40-1.75)mm. 2. The boundary of the sinus tympani was 82.9% from the lower margin oval window to the upper margin round window niche. 3. The deepest part of the sinus tympani was 62.9% in the mid portion, between the ponticulus and subiculum. 4. The oblique dimension from the fossa incudis above to the hypotympanum below was 8.13(7.90-9.55)mm. 5. The transverse dimensions midway between the oval window above and round window below was 3.00(2.85-3.45)mm. 6. The transverse dimension at the level of the fossa incudis was 1.81(1.40-2.15)mm. 7. The facial nerve dehiscence was 14.3%. 8. Anterior-posterior diameter of the footplate was 2.98(2.85-3.05) mm. 9. The average distance from the footplate. 1) to the cochleariform process was 1.42(1.35-1.55) mm. 2) to the round window niche was 1.85(1.45-2.10) mm.