• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.1 s.232
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• pp.63-70
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• 2005

The main objective of the present study is to predict characteristics of three dimensional pulstitile flow by location of stenosis in blood vessel with the second order bifurcation. The present study simulates the incompressible non-Newtonian laminar blood flows using a Fluent V. 6.0. The Carreau model is employed as the constitutive equation for blood. The numerical simulation carried out at five cases without and with symmetry or asymmetry stenosis. It is found that the no stenosis and stenosis before first bifurcation do not have influence on flow at second bifurcated blood vessel. However, the stenosis after first biburcation has effect on flow at second bifurcated blood vessel.

• Korean Journal of Bronchoesophagology
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• v.3 no.2
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• pp.261-269
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• 1997

When performing an endotracheal intubation or tracheotomy to an unconscious patient in emergent situations, one should consider the possibility of later complication of laryngo-tracheal stenosis which can result in difficulties in decannulation. Laryngo-tracheal stenosis is a bothersome problem developing as a complication of treatment by tracheotomy with a cuffed tube and long-term endotracheal intubation with assisted ventilation. One hundred twenty-three cases of laryngo-tracheal stenosis patients during the four yew period from May 1992 to April 1996 were restrospectively reviewed according to several parameters such as the duration of intubation, site of stenosis, treatment modality and, site of tracheostoma. The present report is an analysis of these materials to search for the possible etiologic factors and its proper preventive methods. It was desirable that the endotracheal intubation should be limited within 20 days at most. Tracheotomy performed by non-otolaryngologists has a tendency to be on a higher level of trachea. Technical precautions should be taken into consideration when doing a tracheotomy. The success rate of decannulation of tracheal T-tube was 78.8% and it required average 11 months.

• Journal of Chest Surgery
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• v.16 no.3
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• pp.310-315
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• 1983

The combined anomaly of pulmonary stenosis with atrial or ventricular septal defects is usually associated with decreased pulmonary blood flow and right to left shunt, and result in generalized cyanosis. Non-cyanotic pulmonary stenosis patients have generally been considered to have isolated pulmonary stenosis with intact septa. We are going to report a case of pulmonary stenosis with septal defects who have no frank cyanosis at rest because of the predominant intracardiac shunt from left to right. Recently, we managed surgically a case of pulmonary valvular stenosis combined with secundum type atrial septal defect, type II ventricular septal defect, and patent ductus arteriosus. The clinical manifestations of this patient were exertional dyspnea, frequent upper respiratory infection, chest discomfortness and lethargy since late childhood and these had been progressively aggravated. Pulmonary valvular stenosis, atrial septal defect and ventricular septal defect were closed through simply right atriotomy and patent ductus arteriosus through pulmonary arteriotomy. Immediate postoperative course was uneventful and one year follow up is excellent.

• Journal of Chest Surgery
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• v.22 no.5
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• pp.834-838
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• 1989

Tracheal stenosis is being encountered more frequently as ventilatory support and cuffed tubes are increasingly used for treatment of respiratory failure. We experienced 13 cases of tracheal stenosis treated surgically at department of Thoracic and Cardiovascular Surgery, school of medicine, Kyung Hee university during the 4 years. The causes of tracheal stenosis were prolonged endotracheal intubation 5 cases, tracheostomy 3 cases, tracheal tumor 2 cases, thyroid tumor 1 case and congenital double aortic arch 1 case. The methods used to manage the tracheal stenosis were tracheal resection % end to end anastomosis 8 cases, 2 cases of subglottic stenosis were underwent primary laryngotracheal anastomosis, Lt. aortic arch division 1 case, and stent insertion 2 cases. In two cases, who had 6 cm in length of tracheal stenosis, we were underwent tracheal resection k end to end anastomosis with supralaryngeal release procedure. Postoperative courses were uneventful except one case with tracheal tumor.

• Korean Journal of Radiology
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• v.24 no.3
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• pp.224-234
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• 2023

Magnetic resonance imaging (MRI) is a standard imaging modality for diagnosing spinal stenosis, which is a common degenerative disorder in the elderly population. Standardized interpretation of spinal MRI for diagnosing and grading the severity of spinal stenosis is necessary to ensure correct communication with clinicians and to conduct clinical research. In this review, we revisit the Lee grading system for central canal and neural foraminal stenosis of the cervical and lumbar spine, which are based on the pathophysiology and radiologic findings of spinal stenosis.

• IMMUNE NETWORK
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• v.16 no.1
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• pp.26-32
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• 2016

Aortic valve stenosis is a heart disease prevalent in the elderly characterized by valvular calcification, fibrosis, and inflammation, but its exact pathogenesis remains unclear. Previously, aortic valve stenosis was thought to be caused by chronic passive and degenerative changes associated with aging. However, recent studies have demonstrated that atherosclerotic processes and inflammation can induce valvular calcification and bone deposition, leading to valvular stenosis. In particular, the most abundant cell type in cardiac valves, valvular interstitial cells, can differentiate into myofibroblasts and osteoblast-like cells, leading to valvular calcification and stenosis. Differentiation of valvular interstitial cells can be trigged by inflammatory stimuli from several immune cell types, including macrophages, dendritic cells, T cells, B cells, and mast cells. This review indicates that crosstalk between immune cells and valvular interstitial cells plays an important role in the development of aortic valve stenosis.

• Journal of Chest Surgery
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• v.28 no.10
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• pp.939-941
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• 1995

Congenital esophageal stenosis due to tracheobronchial remnants is one of main forms of congenital esophageal stenosis.A 19-month-old male was presented an appearence of underdevelopment and mild dehydration state due to persistent vomiting since 5 months after his birth. Esophagogram revealed an abrupt narrowing of lower esophagus with dilatation above it. The operation method was aesection of esohageal stenosis and end to end anastomosis through left seventh thoracotomy. The postoperative course was uneventful.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.179-187
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• 2005

The characteristics of blood flow and the interaction between the blood vessel and blood flow play important roles in plaque cap rupture and the growth of atherosclerosis which may lead directly to a heart attack or a stroke. In this study, carotid arteries with different stenoses have been numerically simulated to investigate the wall shear stress(WSS) and the elastic motion of the vessel. Blood flow has been treated as physiological, laminar and incompressible flow. To model the shear thining behavior of the blood, the Carreau-Yasuda model has been employed but the viscoelasticity of blood has not been considered. The results show that the WSS of $severe(75\%)$ stenosis is much higher than those of $25\%\;and\;50\%$ stenosis in the region of stenosis. With the increase in the stenosis thickness, the expansion ratio of the center of the stenosis decreases while the expansion ratio of the upstream region of the stenosis increases.

• The Korean Journal of Pain
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• v.19 no.1
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• pp.63-67
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• 2006

Background: Pain due to spinal stenosis is one of the major causes of low back pain, and it sometimes does not respond to conservative treatment. We postulated that anterior epidural irrigation could be a good choice for treating lumbar spinal stenosis patients. However, the effects and theoretical basis of anterior epidural irrigation have not been investigated for spinal stenosis. So, this study was designed to identify the clinical efficacy of anterior epidural irrigation for treating lumbar spinal stenosis. Methods: 71 patients with lumbar spinal stenosis underwent anterior epidural irrigation. Anterior epidural irrigation was performed with normal saline and a mixture of local anesthetic with steroid through a catheter under fluoroscopic guidance. The findings were evaluated with using visual analogue scales for low back pain and leg symptoms. Results: Relief from low back pain and leg pain was observed for up to 12 months after anterior epidural irrigation. None of the patients showed any deterioration of their motor or sensory deficits during follow up. Conclusions: Anterior epidural irrigation is effective for the relief of back and leg pain in spinal stenosis patients.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.1
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• pp.1746-1749
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• 2019

Background: Surgery has been known as an inefficient approach to reduce back pain in patients with lumbar spinal stenosis; therefore, non-surgical treatments are necessary. However, there has been little research to analyze the effect of non-surgical treatments on lumbar spinal stenosis pain. Objective: To identify the effectiveness of 2 physiotherapeutic treatment approaches to relieve pain due to lumbar spinal stenosis. Design: Randomized controlled trial Methods: The participants were 36 lumbar spinal stenosis patients who were randomized in the joint mobilization group (JMG) and transcutaneous electrical nerve stimulation group (TENSG). Joint mobilization (JM) was conducted at the posteroanterior joint in the spinous process of the lumbar spine with stenosis. Transcutaneous electrical nerve stimulation (TENS) was applied on the lumbar spine with stenosis at a high frequency and intensity. Results: Visual analog scale (VAS) pain score significantly decreased in both groups, and the VAS value decreased more after JMG than that after TENSG. The pain thresholds of both groups also significantly increased, and that of JMG increased more compared to TENSG. In both the groups, significant improvements in VAS and pain thresholds were found, and JMG showed better results than TENSG. Conclusions: JM and TENS showed significant relief in both pain threshold and painpain, and JM showed more advanced relief compared to TENS.