• Journal of Chest Surgery
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• v.36 no.12
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• pp.911-920
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• 2003

In this study, we analyzed the long-term surgical outcome of partial atrioventricular septal defects during the past 17 years at Seoul National University Hospital. Material and Method: A retrospective analysis on mortality, survival, and reoperation and their risk factors was done in 93 patients who underwent surgical correction of partial atrioventricular septal defects between April 1986 and December 2002. 32 patients were male and 61 were female with a median age of 68 months (3∼818 months) and a mean follow-up period of 108 months (1∼200 months). Result: There were 4 operative deaths (4.3%) and one mortality during the follow-up period. 3, 5, 10, and 15 year actuarial survival rates were 95.7%, 94.3%, 94,3%, and 94.3%, respectively. After the surgical correction, left atrioventricular valve Incompetence was improved in 61patients (67.7%), remained same as the preoperative status in 14 patients (15.1%), and was aggravated in 12 patients (12.9%). Reoperation was performed in 8 patients (9.0%) after a mean interval of 38.6 months (3∼136 months). Freedom from reoperation rates at 3, 5, 10, and 15 years after surgical correction were 94.0%, 91.4%, 91.4%, and 88,2%, respectively Reasons for reoperation were 7 left atrioventricular valve incompetence, 2 left ventricular outflow tract obstruction, a residual atrial septal defect, a left atrioventricular valve stenosis, and a right ventricular failure. Left ventricular outflow tract obstruction was the only statistically significant factor. In ten patients, significant arrhythmia was developed and three of them were supraventricular arrhythmia. Complete atrioventricular block occurred in 7 patients and permanent pacemakers were implanted in six of them. Conclusion: Surgical corrections of partial atrioventricular septal defects were performed with low operative mortality. Since left atrioventricular valve incompetence was the most common cause of reoperation and left ventricular outflow tract obstruction was the only risk factor for reoperation, a precise estimation of the left atrioventricular valve morphology and the structure of left ventricular outflow tract are needed. Although left ventricular outflow tract obstruction rarely developed, reoperation was frequently required and resection of subaortic tissue could be peformed but the possibility of recurrence was high, so modified Konno operation could be performed with satisfactory results. Complete atrioventricular block developed frequently in early periods, but was overcome with a precise anatomical understanding of conduction system and experience.

• Journal of Welding and Joining
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• v.13 no.2
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• pp.42-52
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• 1995

In the evaluation of aging degradation on the structural materials based on the fracture mechanics, the detection and size prediction of defect are very important. Aiming at nondestructive detection and size prediction ol defect with high accuracy and resolution, therefore, an lnduced Current Focusing Potential Drop(ICFPD) technique has been developed. The principle of this technique is to induce a focusing current at an exploratory region by an induction wire flowing an alternating current(AC) that is a constant ampere and frequency. Defects are assessed with the potential drops that are measured the induced current on the surface of metallic material by the potential pick-up pins. In this study, the lCFPD technique was applied for evaluating the location and size of the surface crack and blind crack made in plate specimens, and also for detecting the defects existing in valve, a field component, that were developed by SCC etc. during the service. The results of this present study show that surface crack and blind crack are able to defect with potential drop. these cracks are distinguished with the distribution of potential drop, and the crack depths can be estimated with each normalized potential drop that are parameters estimating the depth of each type crack. In the field component, the defects estimated by experiment result correspond with those in the cutting face of the measuring point within a higher sensitivity.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.620-629
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• 1989

A clinical analysis of 138 cases of ventricular septal defect operated on from 1983 to June 1988 at the department of Thoracic and Cardiovascular Surgery, School of Medicine, Chung-nam National University was done. The following results were obtained. 1. The VSD were 27.6 % and 41.0 % respectively of 500 open heart surgery cases and 334 congenital heart disease. 2. The range of age when the VSD was repaired was 3 months to 45 years, the mean age was 10.4 years and the 53.6 % of patients were under 7 years. The sex ratio was 6:4 in males favor. 3. The two common symptoms were frequent upper respiratory infection and dyspnea whose frequency was 62.5 % and 58.7% respectively. 4. 52% of the patients was below 25 percentile of the standard body weight. 5. The most common chest PA findings were cardiomegaly and increased pulmonary vascularity. 6. On anatomical classification, perimembranous type was most common [65.5%], subpulmonary arterial type was 27.6 %, perimembranous plus subpulmonary arterial type was 3.4 % multiple VSD was 0.8 % and LV-RA defect was 2.6 %. 7. Associated cardiac anomalies were founded in 39 cases [35.5 %] and PDA and aortic valve prolapse were most common associated anomalies and extracardiac anomalies were founded in 6.7 % of patients. 8. Mean extracorporeal circulation time was 68 min. and mean aortic cross-clamping time was 42 min. 9. The postoperative complications developed in 26 % of patients and the most common one was minor wound infection. 10. Right bundle branch block developed in 54.8% of the patients who had right ventriculotomy, 40.0% of the patients who had right atriotomy and 10.5% of the patients who had pulmonary arteriotomy. 11. The overall operative mortality was 5.1 % and the operative mortality of the patients who body weigh under 10 Kg was 23.8%.

• Journal of Chest Surgery
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• v.21 no.4
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• pp.649-655
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• 1988

One hundred and one patients with tetralogy of Fallot who were older than 16 years of age underwent a total correction of the anomaly between May, 1964 and July, 1987. This group comprised 14.9% of the 679 consecutive patients who had repair of the tetralogy at our institution during the same period. Of the 101 patients, 8 had a previous shunt procedure for palliation. The preoperative mean hemoglobin value was 16.9*1.0% and the mean systemic oxygen saturation, 84.4*0.9%. In 76 patients[75.2%], a type II ventricular septal defect was seen whereas in 14 patients[13.9%], the defect was type I. In 72 patients[71.3%], other cardiac anomalies were present which included patent foramen ovale in 37.6%, atrial septal defect in 8.99b, vegetations in 6.9%, right sided aortic arch in 5.9% and coronary artery anomaly in 5.0%. The right ventricular outflow obstruction was caused most commonly by combination of infundibular and valvular stenosis[74.3%], followed by isolated infundibular stenosis[19.8%] and valvular stenosis [5.9%] alone in order. The preoperative mean diameter of the pulmonary valve ring size was 10.2*0.5 mm in diameter. A transannular patch enlargement of the right ventricular outflow tract was performed in 28 patients and, in 12 a pericardial monocusp was utilized. Major anomalous aorto-pulmonary vessels were encountered in 5 patients which were detected before or during the operation. In 3 patients, they were ligated beforehand to control the flooding of the operative field. Postoperatively, the mean systolic pressure gradient between the right ventricle and the main pulmonary artery was 16.2*2.3 mmHg and the mean systolic pressure- ratio between the right and the left ventricle was 45.3*2.0%. Perioperative complications including bleeding in 8.9%, pleural effusion in 7.9%, dysrrhythmia in 4.9%, and residual VSD in 4.0%. Operative mortality was 8.9%. There has been no operative death in the recent 65 cases since 1981. There were 2 late deaths, 68 and 113 months after surgery. There were 2 late detachment of the VSD patch during the follow-up period. Of the 6 patients with patch detachment found during the postoperative period, 3 had subacute bacterial endocarditis before or after the operation indicating The serious nature of this complication. Two of these patients subsequently underwent a successful reoperation.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.27-34
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• 2004

Background: Infective endocarditis shows higher operative morbidity and mortality rates than other cardiac diseases. The vast majority of studies on infective endocarditis have been made on aortic endocarditis, with little attention having been paid to infective endocarditis on the mitral valve. This study attempts to investigate the clinical aspects and operative results of infective endocarditis on the mitral valve. Meterial and Method: The subjects of this study consist of 23 patients who underwent operations for infective endocariditis on the mitral valve from June 1995 to May 2003. Among them, 2 patients suffered from prosthetic valvular endocarditis and the other 21 from native valvular endocarditis. The subjects were evenly distributed age-wise with an average age of 44.8$\pm$15.7 (11∼66) years. Emergency operations were performed on seventeen patients (73.9%) due to large vegetation or instable hemodynamic status. In preoperative examinations, twelve patients exhibited congestive heart failure, four patients renal failure, two patients spleen and renal infarction, and two patients temporary neurological defects, while one patient had a brain abscess. Based on the NYHA functional classification, seven patients were determined to be at Grade II, 9 patients at Grade III, and 6 patients at Grade IV. Vegetations were detected in 20 patients while mitral regurgitation was dominant in 19 patients with 4 patients showing up as mitral stenosis dominant on the preoperative echocardiogram. Blood cultures for causative organisms were performed on all patients, and positive results were obtained from ten patients, with five cases of Streptococcus viridance, two cases of methicillin-sensitive Staphylococcus aureus, and one case each of Corynebacteriurn, Haemophillis, and Gernella. Operations were decided according to the AA/AHA guidelines (1988). The mean follow-up period was 27.6 $\pm$23.3 (1 ∼ 97) months. Result: Mitral valve replacements were performed on 43 patients, with mechanical valves being used on 9 patients and tissue valves on the other 4. Several kinds of mitral valve repair or mitral valvuloplasty were carried out on the remaining 10 patients. Associated procedures included six aortic valve replacements, two tricuspid annuloplasty, one modified Maze operation, and one direct closure of a ventricular septal defect. Postoperative complications included two cases of bleeding and one case each of mediastinitis, low cardiac output syndrome, and pneumonia. There were no cases of early deaths, or death within 30 days following the operation. No patient died in the hospital or experienced valve related complications. One patient, however, underwent mitral valvuloplasty 3 months after the operation. Another patient died from intra-cranial hemorrhage in the 31st month after the operation. Therefore, the valve-related death rate was 4.3%, and the valve-related complication rate 8.6% on mid-term follow-up. 1, 3-, and 5-year valve- related event free rates were 90.8%, 79.5%, and 79.5%, respectively, while 1, follow-up. 1, 3-, and 5-year valve- related event free rates were 90.8%, 79.5%, and 79.5%, respectively, while 1, 3-, and 5-year survival rates were 100%, 88.8%, and 88.8%, respectively. Conclusion: The findings suggest that a complete removal of infected tissues is essential in the operative treatment of infectious endocarditis of the mitral valve. It is also suggested that when infected tissues are completely removed, neither type of material nor method of operation has a significant effect on the operation result. The postoperative results also suggest the need for a close follow-up observation of the patients suspected of having brain damage, which is caused by preoperative blood contamination or emboli from vegetation, for a possible cerebral vascular injury such as mycotic aneurysm.

• Journal of Chest Surgery
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• v.39 no.12 s.269
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• pp.900-905
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• 2006

Background: Homografts and bioprostheses are most commonly used for Rastelli operation in congenital heart disease, but the limited durability is responsible for multiple reoperations associated with increased morbidity This study evaluated long-term results after Rastelli operation with a mechanical valved conduit. Material and Method: A total of 20 patients underwent Rastelli operation with mechanical valved conduit from January 1990 to July 1992. Operative mortality was 1 of 20 patients, and a retrospective review of 19 patients(10 males, 9 females) was done. Initial diagnosis was congenitally corrected transposition of great arteries(cc-TGA, n=4), complete TGA (n=2), ventricular septal defect with pulmonary atresia(VSD with PA, n=9), truncus arteriosus(n=2), double outlet right ventricle with pulmonary stenosis(DORV with PS, n=2). The mean age at Rastelli operation was $4.6{\pm}3.4$ years, and mean follow-up period was $12.8{\pm}2.7$ years. Patients underwent Rastelli opearation using 16 CarboMedics mechanical valve, and 3 Bjork-Shiley mechanical valve($17{\pm}2$ mm). Result: There were 15 reoperations for failed mechanical valved conduit. The freedom from reoperation at 5 and 10 years was 53% and 37%. Most patients were received oral anticoagulation with warfarin, and maintained the international normalized ratio(INR) of 1.5 to 2.0. There was no anticoagulation or thromboembolism related complication. There was a significant difference in the causes of a conduit failure between early(within 3 years) and late(after 3 years) failure groups. The six patients reported early prosthetic valve failure, mainly due to valvular dysfunction by thrombosis or pannus formation. The other nine patients reported late prosthetic valve failure, mainly due to dacron conduit stenosis at anastomosis sites, whereas their valvar motion was normal except 1 patient. Conclusion: To avoid early prosthetic valve failure, strict anticoagulation therapy would be helpful. About the late development of obstructive intimal fibrocalcific peels within the Dacron conduit, an improvement of conduit material is necessary to reduce late prosthetic valve failure. In selected patients, the long term results were satisfactory.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.341-346
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• 1999

Background: Thirty children ranging from 3 to 15 years of age underwent cardiac valve replacement at Dongsan Medical Center from 1982 to 1997. Material and Method: There were 16 boys and 14 girls. The mean age was 12.1. The underlying pathological cause for valve replacement was congenital heart disease in 17 children and acquired heart disease in 13. The valve replaced was mitral in 15 children, aortic in 11, tricuspid in 3, and combined aortic and mitral in 1. Twenty-one mechanical and 10 tissue valves were placed: primary mechanical valve have been utilized since 1985. Eight of ten patients with tissue valves have had successful second valve replacements 4 to 11 years after the initial operation. Result: The operative mortality was 6.7%, but mortality was higher among patients less than 5 years of age and patients who had previous cardiac operations. Of the 28 operative survivors, 4 patients were lost to follow-up: the remaining patients were observed for a total of 2091 patient/months(mean 74.7 months, maximum 187 months). There was one late death from dilated cardiomyopathy after mitral valve replacement in 7 year-old patient with atrioventricular septal defect. After the operation, all patients with mechanical valves were placed on a strict anticoagulant regimen with Coumadin. The actuarial survival rate was 96% at the end of the follow-up. No instance of thromboembolism or major bleeding were observed in the survivors. Conclusion: These results indicate that valve replacement can be performed with low mortality in children, and with satisfactory long-term survival.

• Investigative Magnetic Resonance Imaging
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• v.21 no.3
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• pp.183-186
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• 2017

A 7-year-old boy, diagnosed with an arachnoid cyst and subdural effusion on initial MRI, was admitted with left limb weakness and no history of head trauma. A subsequent follow-up MRI showed different stages of hematoma within multilayered enhancing membranes and in the arachnoid cyst, which was separated by the cerebrospinal fluid cleft. Craniotomy and fenestration of the cyst wall and hematoma removal were performed. The patient was diagnosed as a having a hemorrhagic rupture of an arachnoid cyst into the intradural space, probably via some one-way valve-like defect, based on the MRI and surgical findings. The MRI features and possible mechanism of this rare disease are discussed within the literature review.

• Transactions of Materials Processing
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• v.11 no.3
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• pp.246-254
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• 2002

A simple method to derive an optimal pressure curve, characterized by initial pressure, final pressure and pressure path, has been proposed. The initial pressure has been determined from the condition to prevent recoiling phenomenon in the early stage, while the final pressure is from the FE analysis and pressure path is from the punch penetration volume. In order to realize the pressure curve, an open loop control system based on a proportional relief valve has been developed for the renovated CNC hydroforming press. Through the comparison of experiment and analysis, the predicted pressure curve has been verified optimal curve since no defect has been observed.

• Journal of Chest Surgery
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• v.26 no.9
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• pp.701-704
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• 1993

Four to seven percent of infants born with aortic atresia have a normal-sized left ventricle in association with a ventricular septal defect and a normal mitral valve. In contrast to the more common group of infants with aortic atresia whose left ventricle is hypoplastic, this important subgroup has potential for complete operative correction involving both the right and left ventricle. Our approach was to perform complete repair at one stage. The patient who underwent single-stage repair was discharged from the hospital in good condition. Achieving a physiologically normal circulation simplifies the postoperative management of this condition.