• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1919-1922
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• 2003

Bypass anastomosis are frequently adopted for surgical treatments. After the bypass grafting, the bypass artery is often occluded due to restenosis and/or anastomotic neointimal fibrous hyperplasia phenomena. Optimal coronary bypass anastomosis should be investigated to improve the patency for the arterial bypass techniques. The objective of this study is to investigate the influence of bypass with sequential bypass effects in the stenosed coronary artery. Numerical analyses are focused on the understanding of the flow patterns for different sequential anastomosis techniques. Blood flow field is treated as two-dimensional incompressible laminar flow. The finite volume method is adopted for discretization of the governing equations. The Carreau model is employed as the constitutive equation for blood. To find the optimal sequential bypass anastomotic configurations, the mass flow rates at the outlet of different models are compared quantitatively.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제15권1호
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• pp.8-12
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• 2012

The examination of small bowel in Crohn's disease (CD) is very important. Capsule endoscopy (CE) has been recognized as a good tool for evaluation of small bowel. The capsule placement is achieved endoscopically for Children not to swallow capsule. CE is superior to any other modalities for examination of small-bowel. The large portion of pediatric patients with known CD were found with CE to have more extensive and newly diagnostic small-bowel disease. All of them had therapeutic changes. The most side effect of CE is capsule retention. The capsule retention rate in pediatric CD is about 7.3%. The patency capsule helps to predict the possibility of capsule retention. For the improving of the diagnostic accuracy, the experience of more than 20 readings of CE is needed.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.469-476
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• 2011

Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics though arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

• 한국전산유체공학회지
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• 제18권3호
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• pp.14-19
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• 2013

Renal failure patients have to operate arteriovenous graft for hemodialysis. Blood flow characteristics influence the patency rate of arteriovenous graft. Numerical investigation is performed with the arteriovenous graft according to injection of blood. As a result, when the injection is not applied to venous graft, the low wall shear stress region appears at venous anastomosis. It may cause intimal hyperplasia at venous anastomosis.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 1999년도 제38차 추계 학술대회
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• pp.52-52
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• 1999

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.254-257
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• 1996

An aorto-coronary bypass graft is frequently adopted for the interventional therapy of the diseased atherosclerotic coronary artery grafting. The bypass artery is often occluded due to restenosis and/or anastomotic neointimal fibrous hyperplasia after bypass graft. The optimal aorto-coronary bypass procedure must be studied in order to improve patency rate for the arterial bypass techniques. The objective of this study is to investigate the influences of geometric dimensions of bypass on the hemodynamics around the anastomosis in the stenosed coronary artery with aorto-coronary bypass.

• Journal of Chest Surgery
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• 제26권12호
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• pp.920-925
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• 1993

Extra-anatomic bypass was proposed by Freeman in 1952 and has been used for patient with lower extremity arterial occlusion who had very high operative risk, especially elderly or severly illed patient.We had performed 14 cases of extra-anatomic bypasses from Jan. 1991 till July 1993 and having been following up them. Their results were summarized as follow. Among total 14 patients, 13 was male. Their mean age was 64.8 years old, ranged from 48 to 80. The most common complaint was pain on lower limb and they visited hospital 6.1 months in average after onset of symptom. Frequently, they were associated with systemic diseases such as generalized atherosclersis, hypertension, diabetes mellius, etc. Axillary artery was used as donor artery in 8 cases and crossover femoro-femoral or femoro-popliteal bypass was performed in 6 cases. Postoperative complications were notedd in 8 cases so their morbidity rate was 42.8%. Except for two contraindicated cases, one or more anticoagulants were used routinely . Among them, combined use of aspirin and persantine was most commonly applied.After bypass graft, nine cases were occluded beteween 10 and 53 months. So their average duration of freedom from reocclusion was 35.7 months and 3-year patency rate was 63%.

• Journal of Chest Surgery
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• 제21권1호
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• pp.55-61
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• 1988

This report provides follow-up data on 116 patients with congenital cyanotic heart disease, aging 1 month to 13 years [median: 1.8 years], who underwent the modified Blalock-Taussig shunt using polytetrafluoroethylene graft at Seoul National University Hospital between September, 1984 and June, 1987. Among 116 patients complete follow-up studies were done on 95 patients. The mean preoperative arterial oxygen tension was 36 torr. Thirty-Six patients [38%] underwent operation in infancy. Conduit diameters included 4mm [15 cases], 5mm [47 cases], and 6mm [33 cases] sizes. The mean postoperative arterial oxygen tension was 52 torr [P<0.001]. The effectiveness of shunts was evaluated clinically and by shunt murmur, echocardiography and cardiac catheterization with angiography 1 to 31 months after operation. The incidence of shunt occlusion was 9.5% and the mortality was 14.8%. The actuarial patency rate was 83.1 * 6.4% and the actuarial survival rate was 82.5 * 4.5% at 30 months` follow-up for all patients. The effectiveness of the 4mm diameter conduit may be limited. Blalock-Taussig procedure is an effective alternative to the classic B-T shunt in congenital cyanotic heart disease.

• Journal of Chest Surgery
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• 제29권11호
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• pp.1263-1266
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• 1996

단국대학교병원 흉부외과에서는 좌전하행지 기시부부터 95% 이상 협착을 보이는 단일혈관질환 1례에서 체외순환없이 제한적 전흉부 개흉으로 좌측내유동맥을 박리하여 박동심장하에서 관상동맥우회술을 성공적으로 시행하였기에 보고하는 바이다.

• Clinical and Experimental Reproductive Medicine
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• 제14권1호
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• pp.1-6
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• 1987

The Radionuclide test (RN test) using radioactively labelled human albumin microspheres was developed recently to evaluate the patency and functional capacity of the fallopian tubes. 57 infertile women underwent this procedure as a part of their infertility work up. The results of the radionuclide evaluation were compared with those of the hysterosalpingography (HSG) and further the surgical findings of the laparoscopy and laparotomy. In 64.9%(37/57) of the cases, there was complete agreement between radionuclide test (RN test), hysterosalpingography(HSG) and surgical findings. In comparison with surgical findings, RN test showed a complete agreement rate of 89.4%(51/57), a partial agreement rate of 5.3%(3/57) and no agreement rate of 5.3%(3/57), respectively. Likewise, HSG revealed a complete agreement rate of 80.7%(46/57), a partial agreement rate of 10.5%(6/57) and no agreement 8.8%(5/57), respectively. It would appear that as opposed to the traditional HSG, RN test may give a better understanding of the functional capacity of the tube and may prove a useful method before and after tubal surgery.