• Journal of Advanced Marine Engineering and Technology
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• v.35 no.7
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• pp.921-929
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• 2011

We measured experimentally the properties of fluid dynamics, velocity fields, and the pressure, around stenotic obstruction located inside a circular channel structure. Particle image velocimetry system was employed to obtain velocity fields at the central section of the circular channel in the streamwise direction. The stenosis model used was made of acrylic material with different stenotic aspect ratios. The working fluid was water and it was returned by a centrifugal pump system. Pressure measurements were carried out to validate the effect of a narrow passageway. Results showed that the acceleration of gap flow through stenotic obstruction and the pressure drop in the recirculation regime behind the stenosis model can be observed.

• Journal of Chest Surgery
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• v.27 no.7
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• pp.576-580
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• 1994

For 26 months since August 1991, 10 consecutive patients with congenital left ventricular outflow tract obstruction underwent corrective surgery in Pusan Paik Hospital. Their ages ranged from 2 to 18 years. There were 6 male and 4 female patients. According to stenotic site, obstruction were classified into supravalvular [n = 5], subvalvular [n = 4], valvular stenosis [n = 1]. We have performed patch enlargement of ascending aorta [n = 2], supravalvular membrane resection and patch enlargement of ascending aorta [n = 3], subvalvular membrane resection [n = 2], subvalvular membrane resection and left ventricular myectomy [n = 2] and aortic annuloplasty with Dacron patch and aortic valve replacement [n = 1]. Preoperative mean value of systolic pressure gradient were 85.0 $\pm$29.2mmHg[supravalvular], 70.0mmHg[valvular], 72.5 $\pm$ 22.5mmHg[subvalvular], and 78.5 $\pm$ 24.3mmHg[total]. Postoperative mean value of systolic pressure gradient were 31.0 $\pm$ 8.9mmHg[supravalvular], 0mmHg[valvular], 15.0 $\pm$ 10.8mmHg[subvalvular], and 21.5 $\pm$ 13.9mmHg[total]. Postoperative systolic pressure gradient was decreased significantly[p = 0.001]. Postoperative course and short-term follow up results were good except one case of transient heart failure.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.278-283
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• 2004

Meckel's diverticulum is found in about 3% of the population, often incidentally during laparotomy or at autopsy. Over 50% of patients who develop symptoms from this anomaly are younger than 2 years of age. The most common symptom of this lesion is intestinal obstruction. Rarely Meckel's diverticulum is complicated by a mesodiverticular band, which is believed to be a remnant of a vitelline artery. We report a 11-year-old girl with small bowel obstruction because of an intestinal hernia beneath the mesodiverticular band. The causative factor was a stenotic area in the terminal ileum caused by a ringlike lipovascular mesenteric band encroaching externally on the lumen. Although the incidence of mesodiverticular bands complicating Meckel's diverticulum is quite low, the rapid clinical course and the associated high mortality rate make this an important disease.

• Journal of Chest Surgery
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• v.32 no.1
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• pp.10-15
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• 1999

Background: Mitral valve replacement with chordal preservation in patients with mitral regurgitation has been proved to be beneficial for left ventricular function and for reduction of postoperative complication. However, in patients with mitral stenosis, the effectiveness of the technique is controversial. It is not easy to insert prosthetic valve without left ventricular outflow tract obstruction and prosthetic valve leaflet motion hinderance. Material and Method : Five patients with mitral stenosis and seven patients with mitral stenoinsufficiency underwent mitral valve replacement with preservation of mitral subvalvular apparatus. Thickened and calcified leaflets are made thin by peeling off the thickened and calcified part. Commissurotomy was done and anterior leaflet was incised 2 mm apart from the annulus and then divided into two segments. Anterolateral and posteromedial segments including strut chordae, were reattached to mitral commissural area, respectively. Result: There was no evidence of prosthetic valve dysfunction, paravalvular leakage, left ventricular outflow tract obstruction, complications and operative or late deaths. Conclusion: We conclude that mitral vlave replacement with chordal preservation was safe and effective technique for the patients with mitral stenotic disease.

• Tuberculosis and Respiratory Diseases
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• v.38 no.4
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• pp.347-356
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• 1991

Endobronchial tuberculosis is a serious disase because it frequently leaves airway obstruction as the complication, and the treatment of airway obstruction is generally troublesome. In the tumorous type of endobonchial tuberculosis, the bronchial patency is partially or completely compromised with lymph node contents when the necrotic focus of the lymph node ruptures into the bronchial lumen to form a bronchoglandular fistula. To investigate the transition of endobronchial lesion and to evaluate the therapeutic role of bronchoscopic electrocautery in the tumorous type of endobronchial tuberculosis, we performed electrocautery in addition to the combination chemotherapy with steroid and anti-tuberculous drugs in two cases which had airway obstruction proximal to lobar bronchus with the impairment of pulmonary function. We also treated another two cases only with chemotherapy and we have followed up four cases over a 36-month period. In cases that bronchoscopic electrocautery was done, the bronchial patency was completely restored and the impairment of pulmonary function disappeared just after cautery and these effects have remained for 12 months or more. But in cases of medical treatment only, bronchial stenosis was inevitable as the tumorous type of endobronchial tuberculosis changed to the stenotic type with fibrosis. It can be concluded that bronchoscopic electrocautery can nip the occurence of bronchial stenosis in the bud when it is applied in addition to combination chemotherapy with steroid and antituberculous drugs in the tumorous type of endobronchial tuberculosis.

• International Journal of Vascular Biomedical Engineering
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• v.2 no.1
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• pp.25-30
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• 2004

Catheters are used to measure translesional pressure gradients in the stenosed coronary arteries. Uses of catheters during coronary angioplasty cause flow obstructions. A narrowed flow cross section with catheter effectively introduced a tighter stenosis than the enlarged residual stenoses after balloon angiplasty. Catheters in blood vessels cause pressure gradient rise and blood flow drop during the measurements. In this study, three dimensional computer simulations are conducted to investigate the flow blockage effects due to the catheter obstructions during the coronary angioplasty. The computer simulation models are generated by the data, which are measured by coronary angiogram, and the blood is treated as non-Newtonian fluid. The velocity, pressure, and wall shear stress variations are observed for the estimate of damages of blood vessel. This study is also extended to investigate the effects of stenotic vessel size, and shape and catheter size and location.

• Journal of Chest Surgery
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• v.32 no.1
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• pp.75-79
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• 1999

Budd-Chiari syndrome is a state of hepatic failure caused by impairment of blood flow anywhere from the inferior vena cava to the right atrium. In this case, a 45 year old patient had undergone membranotomy and dilatation with autogenous pericardial graft due to obstruction of the inferior vena cava caused by a congenital membrane in 1987. Ten years after the operation, restenosis occurred. Although a noninvasive method with a Gianturco stent dilatation was performed, a satisfactory result was not obtained. A reoperation was performed. The stenotic segment of inferior vena cava was excised and after augmentation with a prepared pentagon shaped Gore-Tex artificial graft allowing passage of two fingers. The patient's postoperative course was uneventful without signs of rebleeding or any other complications and the patient was discharged at postoperative two weeks without the use of anticoagulants. An excellent result was obtainable after operation using a prepared Gore-Tex graft and such a result. Reoperational case of Budd-Chiari syndrome may require rapid and excellent the operative techenic by prevention of massive bleeding under use of extracorporeal circulation.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.26 no.4
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• pp.193-200
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• 2023

Purpose: Crohn's disease (CD) is a chronic, idiopathic bowel disorder that can progress to partial or complete bowel obstruction. At present, there are no reliable diagnostic tests that can readily distinguish between acute inflammatory, purely fibrotic and mixed inflammatory and fibrotic. Our aim is to study the utility of contrast enhanced ultrasound (CEUS) in combination with shear wave elastography (SWE) to differentiate fibrotic from inflammatory strictures in children with obstructive CD of the terminal ileum. Methods: Twenty-five (19 male) children between 2016-2021 with CD of the terminal ileum were recruited into the study. Among these patients, 22 had CEUS kinetic measurements of tissue perfusion, including wash-in slope (dB/sec), peak intensity (dB), time to peak intensity (sec), area under the curve (AUC) (dB sec), and SWE. In total, 11 patients required surgery due to bowel obstruction. Histopathologic analysis was performed by a pathologist who was blinded to the CEUS and SWE test results. Results: Patients that underwent surgical resection had significantly higher mean area under the curve on CEUS compared to patients responsive to medical therapy (p=0.03). The AUC also correlated with the degree of hypertrophy and the percent fibrosis of the muscularis propria, as determined by histopathologic grading (p<0.01). There was no difference in the mean elastography measurements between these two patient groups. Conclusion: CEUS is a useful radiological technique that can help identify pediatric patients with medically refractory obstructive fibrotic strictures of the terminal ileum that should be considered for early surgical resection.

• Journal of Chest Surgery
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• v.19 no.2
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• pp.280-287
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• 1986

Between March 1978 and August 1985, 29 cases at various congenital heart diseases were reoperated because of remnant shunt of residual anomalies at Seoul National University Hospital. They were consisted of 10 cases of Tetralogy, 4 simple VSD, 6 complicated VSD. 3 partial ECD, and 5 other rare congenital anomalies. The interval between the initial and the second procedure ranged from 1 day to 122 months [mean; 26.9 months]. In 4 cases of them, the second procedure was done during initial hospitalization within 3 weeks post-operatively. The primary operation intended to be corrective surgery except four whose primary operation was palliative or exploratory one even though it was done with extracorporeal circulation. The indication for second operation was mainly residual shunt or valvular obstruction due to patch detachment or inadequate relief of stenotic lesion. Others were paravalvular leak, valvuloplasty failure, prosthetic valve failure, and inadequate primary diagnosis. Four patients were dead [14.3%]; three complicated VSD`s and one Tetralogy. There were 7 cases of nonfatal complication with subsequent improvement except one [diffuse cerebral dysfunction].

• Journal of Chest Surgery
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• v.17 no.3
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• pp.381-388
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• 1984

Cor triatriatum is rare congenital cardiac anomaly first described by Church in 1868. The anomaly consists of an abnormal partitioning of the left atrium by a fibromuscular membrane that divides the atrium into an upper chamber, which receives the pulmonary veins, and a lower chamber, which contains the atrial appendage and the mitral valve. The upper and lower chambers communicate through a stenotic fenestration in the membrane, which has the hemodynamic consequence of pulmonary venous obstruction. Recently we experienced cot triatriatum associated with partial anomalous pulmonary drainage to right atrium. The upper chamber was connected to right atrium through a sinus venous type of ASD and received left superior and both inferior pulmonary vein, whereas the lower chamber so called true left atrium communicated with right atrium through foramen ovale type of ASD, left atrial appendage and mitral orifice. And the anomalous membrane has no fenestrations which permit blood flow. The operation was made right atrial approach under the CPB. We excised completely the anomalous septum and reconstructed atrial septal defect with pericardial patch to drain the right upper pulmonary vein to the left atrium. The postoperative course has been good during follow up.