• Advances in pediatric surgery
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• v.1 no.2
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• pp.149-161
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• 1995

The first national survey on esophageal atresia and tracheoesophageal fistula was conducted to access the current status of its incidence, clinical manifestation, preoperative diagnosis and management, type of its anomaly, associated anomalies, and surgical results and course. The 43 members of the Korea Association of Pediatric Surgeons received questionnaires and registration forms to be filled out on each patient who were born during the three years from January 1, 1992 through December 31, 1994. Questionnaires composed of six broad areas which include 1) preoperative diagnosis and management, 2) surgical technic, 3) long gap, 4) postoperative management, and 5) complications and courses. A total of 148 cases was returned by 28 members working at 23 institutions and 27 members returned questionnaires. We obtained the following results by analysis of the 148 cases of tracheoesophageal anomalies. The incidence of tracheoesophageal anomaly was about 1/10,000-11,000 in 1994, which is one third of that of anorectal malformations in Korea and the distribution of the patients was almost proportionate to the size of each province. Both sexes are about equally affected. Majority of the members make diagnosis of tracheoesophageal anomaly by taking a simple infantogram with a radiopaque tube in upper pouch and a little under half(46%) prefers to perform echocardiography as a part of preoperative management to identify congenital heart disease and lateralize the aorta. Esophageal atresia with distal TEF(87.5%) was by far the most common and there were pure esophageal atresia(5.6%), H-type TEF(2.1%), and so on. About half(49%) of the patients had one or more associated anomalies in addition to tracheoesophageal anomalies. Congenital heart disease was associated in 46 cases(31%), anorectral malfomations in 19 cases(13%), musculoskeletal anomalies in 15 cases(10%), genitourinary anomalies in 10 cases(7%) and gastrointestinal anomalies in 7 cases(5%). Postoperatively, parenteral nutrition and assisted ventilation were given in 66% and 52% of patients respectively. Ninety three(74%) of 126 cases who underwent sugical procedure, experienced one or more complications such as respiratory complication(65%), leak(22%), stricture(21%) and so on. The survival rates related to the Waterston risk categories were 90.2% in group A, 71.4-75% in $B_1$, $B_2$, and $C_1$, groups, and 28% in group $C_2$, and the overall survival rate was 71.4%. Thirty six(28.6%) of 126 cases died of pneumonia/sepsis(12 cases), respiratory failure(12 cases), and congenital heart disease(4 cases). With short term follow-up, 69% of patients have been excellent whereas remainders of the cases have suffered from some sort of morbidity related to gastroesophageal reflux, recurrent respiratory infection, and esophageal stricture.

• Journal of Technology Innovation
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• v.19 no.3
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• pp.1-29
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• 2011

Korean government built "2040 Science and Technology Future Vision" in order to show positive future scenarios and suggest a long-term guideline for a progress in science and technology. The S&T Future Vision was built based on an analysis of global megatrends and a prospect of domestic social change. After building S&T Future Vision, the "Government R&E Strategy"s was established as a follow-up action plan. The Government R&D Strategy consists of lists of future emerging technologies for future leadership, government R&D investment status and investment portfolio plans. Exploring future emerging technologies aggressively and making a governmental R&D strategic policy are requirements for national competitiveness, leadership in the world. Therefore search and selection for future emerging technologies is getting more and more important recently. Generally qualitative methodologies have been used such as expert-panel discussion method and portfolio analysis with expert valuation method in order to explore future technologies. These experts-based qualitative methodologies are well defined but lacking in some objectivity because size of expert-panels has limitations. We suggest a quantitative methodology, science mapping method to compensate this shortcoming in this study. There is another limitation related governmental R&D strategy which is that general R&D portfolios are static until a point of technology realization. We also propose a dynamic R&D investment portfolio which present different portfolios at a intermediate point and a point of technology realization. We expect this try with science mapping method and a dynamic R&D portfolio could strengthen strategic aspect of government R&D policy.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.727-734
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• 2004

The Lecompte procedure for transposition of the great arteries has an advantage because it obviates the need for an extracardiac conduit for the reconstruction of the pulmonary outflow tract. We evaluated the effectiveness and the application of the Lecompte procedure. Material and Method: A retrospective review was conducted of the records of 46 patients who underwent the Lecompte procedure during the past 15 years. Mean age at operation was 29.2$\pm$20.3 (range: 3∼83) months. The diagnoses involved anomalies of the ventriculoarterial connection with ventricular septal defect and pulmonary outflow tract obstruction, such as transposition of the great arteries, double-outlet right ventricle, and double-outlet left ventricle. Result: Early mortality was 4.4% (2 of 46 patients) and late mortality was 6.8% (3 of 44). The mean follow-up was 11.2$\pm$6.9 years. Eighteen patients (43.9% of survivors, n=41) had pulmonary stenosis (pressure gradient above 30 mmHg), the main reason for which was a calcified monocusp valve (n=15, 83.3%). Seventeen of 46 patients (37.0%) underwent reoperation: 15 for pulmonary stenosis, 5 for residual ventricular septal defect, 4 for left ventricular outflow tract obstruction, 3 for pulmonary insufficiency, and 4 for other causes. The cumulative survival rates were 91.3$\pm$4.2%, and 87.0$\pm$5.8% at 10 and 15 years, respectively. The actuarial probabilities of freedom from reoperation for pulmonary stenosis were 90.6$\pm$4.5%, 73.9$\pm$7.3%, and 54.0$\pm$10.4% at 5, 10, and 15 years, respectively. Conclusion: The Lecompte procedure is an effective treatment modality. Repair in early age is possible with acceptable morbidity and mortality, but recurrent right ventricular outflow tract obstruction caused by degeneration of the monocusp valve is a problem that needs resolution.

• Journal of Chest Surgery
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• v.40 no.12
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• pp.825-830
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• 2007

Background: Minimally invasive cardiac surgery appears to offer certain advantages such as earlier postoperative recovery and a greater cosmetic effect than that achieved through conventional sternotomy. However, this approach has not yet been widely adopted in Korea to replace complex open heart surgery such as mitral valve reconstruction. This study compared the results of robot assisted minimally invasive mitral valve repair with those results of conventional sternotomy. Material and Method: From December 1993 to December 2005, 520 consecutive patients underwent mitral valve reconstruction for mitral regurgitation in our institution. These patients were subdivided according to those whose surgery used the conventional sternotomy approach (Group S, n=432) and those who underwent minimally invasive right anterior thoracotomy (Group M, n=88); we then compared the clinical results of both groups. When we performed minimally invasive right thoracotomy, we used a robot (AESOP 3000) and made an incision less than 5 cm. Result: Our study patients in both groups were similar for their age, gender and preoperative ejection fraction. There were two hospital mortalities in group S. but there was no mortality in the group M patients. Significant reductions in the ICU stay and the postoperative hospital stay were observed in the group M patients compared with the group S patients. However, both the bypass time and the aortic cross-clamp time were significantly longer in the group M patients. In spite of the confined incision in the group M patients, there were no limitations on the mitral valve repair techniques. There was a similar frequency of postoperative significant residual mitral regurgitation in both groups. Conclusion: In this study, the minimally invasive mitral valve repair showed comparable early results with the conventional sternotomy patients. We will now need long-term follow-up of these patients who underwent minimally invasive mitral valve repair, but we anticipate that based on the results of this study, we will begin to routinely perform minimally invasive cardiac surgery as out primary approach for mitral valve reconstruction.

• Journal of Chest Surgery
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• v.31 no.10
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• pp.919-923
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• 1998

Background: Calcific degeneration is unavoidable in either homo- or heterografts implanted in the human body. We have developed a calcification-resistant cardiovascular tissue patch using a novel technique of anticalcification. Materials and methods: Fresh bovine pericardium was harvested at the slaughter house and transfered to the laboratory in Hank's solution. After trimming and fixing the pericardium, it was embedded in 4$^{\circ}C$ 0.65% glutaraldehyde for a week and then washed by phosphate-buffered saline(PBS) of pH 7.4. This prepared pericardium was then stored in 2.5% sulphonated polyethyleneoxide(PEO-SO3) solution for 2 days at room temperature and reversed by 4$^{\circ}C$ NaBH4 solution for 16 hours. To evaluate the calcification-resistance of surface modified bovine pericardium with PEO-SO3, either glutaraldehyde- treated(GA group, n=4) or PEO-SO3-treated pericardial patch(PEO-SO3 group, n=4) was implanted into adult mongrel dog to reconstruct the main pulmonary artery and the descending aorta using a partial clamp technique. After 1 month follow-up, the implanted patches were retrieved to evaluate the pathologic findings and the content of calcium and phosphorous. Results: The PEO-SO3 group showed substantially less retraction and significantly less calcium deposition than the GA group in both aortic(7.10$\pm$1.05 vs. 13.81$\pm$2.33 mg/g of dried tissue) and pulmonary positions(1.55$\pm$0.29 vs. 6.72$\pm$0.70 mg/g)(p<0.01). Phosphorous contents were also less in the PEO-SO3 group than the GA group significantly, 8.11$\pm$1.07 mg/g vs. 19.33$\pm$4.31 mg/g in the aortic and 2.58$\pm$0.40 vs. 12.60$\pm$3.40 mg/g in thepulmonary position(p<0.01). Conclusions: These findings suggest that PEO-SO3 modified bovine pericardium is highly calcification-resistant but further study is needed to evaluate the long-term biological safety and compatibility of the prosthesis.

• Tuberculosis and Respiratory Diseases
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• v.47 no.1
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• pp.66-76
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• 1999

Background : To assess the utility of HRCT in the evaluation of visceral pleural invasion and to determine whether visceral pleural invasion and bronchovascular bundle thickening on the same lobe could be related to the recurrence and survival in non-small cell lung cancer (NSCLC) Method: Eighty one patients, which were fulfilled long-term follow-up at least 18 months (maximum 103 months) among which 434 patients had underwent curative surgical resection for NSCLC from 1986 to 1995, were studied. They were analyzed to evaluate whether the prognostic factors such as the recurrence and survival depend on visceral pleural invasion and bronchovascular bundle thickening to the same lobe. Thirty two patients adjacent to a chest wall or a fissure were evaluated for visceral pleural invasion by HRCT. CT criteria included abutting pleura along the chest wall, abutting and/or compressing fissure, croosing fissure, and pleural tail. Results: The positive predictive value and the negative predictive value of crossing fissure were 100% and 100%, respectively. Two patients showing spiculated interface between a mass and abutting fissure were confirmed to have visceral pleural invasion at surgery. Visceral pleural invasion confirmed at surgery was significant to local recurrence and survival (p<.05. p<.05, respectively). Brochovascular bundle thickening to the same lobe on CT scan was significant to survival (p<.05) but was not significant to local and distant recurrence (p>.05). Conclusion : Visceral pleural invasion and bronchovascular bundle thickening to the same lobe have a role in predicting prognosis such as recurrence and survival in NSCLC. Therefore, the analysis of visceral pleural invasion on CT scan and the pathological analysis of bronchovascular bundle thickening to the same lobe may be necessary to predict the prognosis in NSCLC.

• Childhood Kidney Diseases
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• v.5 no.2
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• pp.164-175
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• 2001

Purpose : Alport syndrome is a hereditary nephrotic disease characterized by progressive nephrotic symptom, sensorineural hearing loss, ophthalmic abnormality, typical microscopic findings, and familial occurrence. In this study, we tried to find the risk factors related with its prognosis by taking a close observation on clinical symptoms of children with Alport syndrome reviewing retrospectively. Materials & methods : We chose children diagnosed as Alport syndrome in renal biopsy during 20 years(from 1980, Jan. until 1999, Dec.) who could receive follow up studies in tile department of pediatrics. They were divided into two groups by comparing renal function at the time of diagnosis and at current status. We compared several clinical aspects in them, and applied nonparametric test for statistical analysis. Results : The sex ratio(male:female) of 24 children was 3:1. The most common clinical symptom presented at their first visit was gross hematuria. Among those 24 children, 11 cases($46\%$) of progressing into chronic renal failure(Group II) were observed. Hypertension, proteinuria and edema were seen much frequently in group II. The level of serum protein, albumin, and creatinine clearance were decreased while BUN, creatinine were relatively increased. All the results were statistically significant. Conclusion Clinically significant risk factors related to prognosis in Alport syndrome were the presence of hypertension, edema, and proteinuria at the time of diagnosis. Also, the level of serum protein, albumin, BUN, creatinine, and glomerular filtration rate were proved to be important factors in predicting prognosis. We believe that studies on these possible risk factors would be of great help in treating and predicting prognosis of children suffering with Alport syndrome. (J Korean Soc Pediatr Nephrol 2001;5 : 164-75)

• Radiation Oncology Journal
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• v.12 no.3
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• pp.361-368
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• 1994

Purpose : Testicular seminomas are radiosensitive and adjuvant radiation therapy after orchiectomy results in long term survival in early stage diseases, Ten year results of radiation therapy after orchiectomy and results of definitive treatment of recurrent seminoma are Presented. Materials and Methods : Between August 1980 and February 1990. 32 Patients with testicular seminomas were treated at the Department of Therapeutic Radiology, Seoul Natoinal University Hospital. Twenty-seven Patients received radiation therapy after orchiectomy and 5 patients for treatment of recurrent tumors. Two of postoperatively treated patients and 2 of recurrent patients were excluded from the study because of incomplete treatment. Of the patients treated postoperatively, 18 were stage I, 5 were stage IIA, one was stage IIB, and one was stage IIC. There were 4 ipsilateral and 2 contralateral cryptorchids. Preoperatively, ${\beta}$-HCG levels were elevated in 5 patients. Median dose to pelvic and paraaortic lymph node area was 2900 cGy (1550-4550 cGy). One patient with stage I, 4 with stage IIA, and 1 with stage IIB received prophylactic mediastinal irradiation. Two patients were treated with chemotherapy before radiation therapy. Median follow-up period was 104(3-144) months. Result: Local control rates were 100% at 5 years after orchiectomy. Five year survival rates were 94.4% in Stage I and 100% in Stage II patients, One patient with stage I disease died 3 months after surgery due to mediastinal metastasis. AII the 3 patients treated for recurrent disease are alive without disease. Conclusion : Postorchiectomy radiation to the pelvis and para-aortic area remains the treatment of choice for Patient with early stage testicular seminoma. Radiation therapy is also an excellent treatment modality for recurrent seminoma.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.715-721
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• 1999

Background:The number of old patients receiving coronary artery bypass grafting(CABG) is increasing. With the more recent advances in operative techniques, the age at which CABG is indicated has also increased. This study evaluated the risk factors associated with the hospital mortality and the morbidity following CABG in elderly patients. Material and Method: Between March 1991 and June 1998, we retrospectively reviewed 45 consecutive patients aged 65 years or older who underwent CABG. We compared the data with the results of 179 patients under the age 65 years operated during the same period. Result: Mean age was 68${\pm}$1.41 years(range 65 to 74 years). Emergency surgery was required in 4, and elective surgery in 41 patients. The mean number of distal anastomosis per patient was 3.62 ${\pm}$0.81 and mean aortic cross-cramp time was 69.84${\pm}$18.5 minutes. Thirty patients had Canadian class III or IV preoperatively, but 43 patients had class I or II postoperatively. The left ventricular ejection fraction increased significantly from 54.23${\pm}$10.62% preoperatively to 58.14${\pm}$9.88% postoperatively(p<0.05). Postoperative complication was pneumonia in 2 patients, acute renal failure in 2 patients, sternal wound infection in 1 patient, and postoperative myocardial infarction in 1 patient. There were two postoperative deaths. The causes of deaths were low output syndrome in one patient, and sepsis due to pneumonia in the other patient. The hospital mortality was higher in the elderly group(4.4 versus 2.86%) but was not statistically significant(p>0.05). Incremental risk factors for hospital deaths in the elderly were emergent operation, preoperative PTCA, postoperative use of IABP and postoperative ARF(p<0.05). The duration of hospital stay after operation was significantly longer for the elderly group than the younger group(19.27${\pm}$12.51 vs 15.55${\pm}$6.99 days; p＜ 0.05). Follow-up was complete for 34 of the hospital survivors and ranged from 1 to 73 months(mean: 23.58${\pm}$19.56 months). There was no late mortality of cardiac origin. Conclusion: Age is an important factor in selecting optimal management for elderly patients with coronary compromise, but age alone should not dictate the choice of therapy. Coronary artery bypass surgery in the elderly is associated with acceptable early mortality and excellent long-term results.

• Journal of Chest Surgery
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• v.30 no.10
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• pp.949-960
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• 1997

Background. Limited ischemic tolerance of the lung has remained one of the factors that limits the expansion of pulmonary transplantation as a treatment for end-stage pulmonary disease. Numerous studies on safe long term preservation for lung transplantation has been performed for the purpose of developing ideal preservation solution with extracellular type or intracellular type solutions. In this. study, we examined the efficacy of L DG solution in lung preservation longer than 20 hours by comparison with modified Euro-Collins solution. Iwethods. Thirty-(our adult mongrel dogs were divided into two groups. Donor lungs were flushed with LPDG solution(n=9) or modified Euro-Collins(MEC) solution(n=8) and stored for 24 hours at 1$0^{\circ}C$. All donor lungs were perfused through the pulmonary arteries with solutions containing prostaglandin El and verapamil. Left canine lung allotransplantations wereperformed. Assessment(hemodynamic indices and arterial blood gas analysis) of left implanted lung was made by occluding the right pulmonary artery for ten minutes using pulmonary artery Cuff. Assessment was repeated at the interval of 30 minutes, one hour, and two hours later after reperfusion and then chest X-ray, computed tomogram and lung perfusion scan were obtained. In survival dogs follow-up studies were done with assessment with chest X-ray, computed tomogram of the chest and lung perfusion scan on 7th day postoperatively. After preservation above 20 hours, pathological examinations for ultrastructural findings on right lung were performed in each group. Results. With respect to arterial oxygen tension, LPDG group was superior to MEC but there was no statistical significance for 2 hours after reperfusion. Mean pulmonary artery pressure was less increased(p < 0.05) and cardiac output higher(p <0.05) than MEC group until 2 hours after reperfusion. After 2 hours of reperfusion, both groups showed transplanted lung function deteriorated gradually. Perfusion scan of the transplanted lung in LPDG group showed better perfusion rate in immediate post-reperfusion, 3 days and 7 days later respectively but there was no statistical significance and corelation with PaO2 and computed tomoRravhic views. In scanning electron microscopy of pulmonary artery after preservation, LPDG group relatively shows less irregular protrusion of the inner surface of endothelial cell of poulmonary artery than MEC group. Conclusions, e concluded that LPDG solution can offer safe lung preservation above 20 hours with adequate immunosuppressive therapy and prevention of the infection.