• Journal of Chest Surgery
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• 제44권2호
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• pp.89-98
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• 2011

Background: Although considerable efforts have been made to improve the graft patency in coronary artery bypass surgery, the role of biomechanical factors remains underrecognized. The aim of this study is to investigate the influences of geometric configurations of the bypass graft on hemodynamic characteristics in relation to anastomosis. Materials and Methods: The Numerical analysis focuses on understanding the flow patterns for different values of inlet and distal diameters and graft angles. The Blood flow field is treated as a two-dimensional incompressible laminar flow. A finite volume method is adopted for discretization of the governing equations. The Carreau model is employed as a constitutive equation for blood. In an attempt to obtain the optimal aorto-coronary bypass conditions, the blood flow characteristics are analyzed using in vitro models of the end-to-side anastomotic angles of $45^{\circ}$, $60^{\circ}$ and $90^{\circ}$. To find the optimal graft configurations, the mass flow rates at the outlets of the four models are compared quantitatively. Results: This study finds that Model 3, whose bypass diameter is the same as the inlet diameter of the stenosed coronary artery, delivers the largest amount of blood and the least pressure drop along the arteries. Conclusion: Biomechanical factors are speculated to contribute to the graft patency in coronary artery bypass grafting.

• 대한의용생체공학회:의공학회지
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• 제10권2호
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• pp.139-150
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• 1989

새로운 형태의 인공심장용 전동기구동형 혈액동기구동행 혈액 펌프플 개발하였다. 개발된 혈액 펌프는 소형, 고출력, 브러쉬 없는 직류 전동기를 에너지 변환 장치로 사용하였으며, 이 전동기 자체가 원호 형태의 궤적을 따라 좌우로 회전하도록 고안되었으며, 전동기를 포함한 '회전원통'의 웅직임이 좌우에 부착되어 있는 폴리우레탄으로 제작된 혈액 주머니를 번갈아 밀게 되어 혈액을 박출하게 된다. 본 연구에서 도입한 이동형 작동기 원리에 의해 다른 전동기 구동형 혈액 펌프가 안고 있는 두가지의 중요한 문제점인 펌프 크기의 증가와 자연 심장과의 해부학적인 구조상 접합의 문제점들을 개선할 수 있었다. 또한 펌프의 효율과 전동기에 의한 시스템의 온도 상승, 그러고 펌프 내에 유입되는 유체에 대한 이론적 해석을 실시하였으며, 일련의 모의 순환 실험을 통해 실험 결과를 비교하였다. 개발된 펌프 시스템은 이식형 완전 인공 심장으로 사용하기에 충분한 심박출량(9 L/m)과 전부하에 민감한 반응, 그리고 기계적인 안정도를 보여 주었다.

• 한국임상수의학회지
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• 제23권1호
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• pp.55-60
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• 2006

Aucuba japonica has variable pharmacological effects such as hepatoprotective, choleretic, hemodynamic, antimicrobial, and anti-inflammatory activities. This study was performed to investigate the effects of Aucuba japonica extract on oral wound healing. Aucubin was extracted from Aucuba japonica, and injected on either side of buccal mucosa of male mice. Artificial full thickness wounds were made on the site with 1.5 mm biopsy punch under sterile technique. The specimens had taken on day 1, 3, and 5 with 4 mm biopsy punch. Light microscopic examination and quantitative histologic analysis were performed for reepithelization, inflammatory cell infiltration. Reepithelization of the aucubin (0.1%) group was earlier than the control group. And the number of inflammatory cells of the aucubin group was lesser than the control group. In view of the results so far achieved, the aucubin extracted from Aucuba japonica may be useful for oral wound healing and it can be applied as a topical agent on the oral wound. Further research should be performed on the mechanism of aucubin on oral wound healing and proper formulation for effective topical agents.

• Journal of Chest Surgery
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• 제33권2호
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• pp.125-131
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• 2000

Background: Hyperinflation during lung ischemia has been known to improve pulmonary functions after reperfusion which may be exerted through a pulmonary vasodilation and avoidance of atelectasis by an increased surfactant release and been known whether the improvement of pulmonary function was the effect of hyperinflation itself or the oxygen content in inflation gas. Therefore we attempted to clarify the effect of hyperinflation with oxygen in pulmonary inflation gas during warm ischemia on pulmonary function after reperfusion to solve the problem of ischemia-reperfusion injury after lung transplantation. Material and Method: sixteen mongrel dogs were randomly divided into two groups: the left lung was inflated to 30-35 cm H2O with 100% oxygen in oxygen group and 100% nitrogen in nitrogen group. The inflated left lung was maintained with warm ischemia for 100 minutes. Arterial and mixed venous blood gas analysis and hemodynamics were measured before ischemia and 30, 60, 120, 180 and 240 minutes afer reperfusion. Lung biopsy was taken for the measurement of lung water content after the end of reperfusion. Result: In oxygen group arterial oxygen tension the difference of arterial and mixed venous oxygen tension and the difference of alveolar-arterial oxygen tension at 30-minute after reperfusion were not significantly different from those before ischemia and were stable during the 40hour reperfusion. However in nitrogen group these values were significantly deteriorated at 30-minute after reperfusion. there was no significant difference between two groups in hemodynamic data peak airway pressure and lung water content. Conclusion : The results indicated that the oxygenation one of the most important pulmonary functions was improved by pulmonary inflation with 100% oxygen during warm ischemia but the hemodynamics were not. Oxygen as a metabolic substrate during warm ischenia was believed to make the pulmonary tissues to maintain aerobic metabolism and to prevent ischemic damage of alveoli and pulmonary capillary.

• Journal of Trauma and Injury
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• 제34권2호
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• pp.81-86
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• 2021

Purpose: This study investigated the clinical outcomes of trauma patients with blunt thoracic aortic injuries at a single institution. Methods: During the study period, 9,501 patients with traumatic aortic injuries presented to Trauma Center of Gil Medical Center. Among them, 1,594 patients had severe trauma, with an Injury Severity Score (ISS) of >15. Demographics, physiological data, injury mechanism, hemodynamic parameters associated with the thoracic injury according to chest computed tomography (CT) findings, the timing of the intervention, and clinical outcomes were reviewed. Results: Twenty-eight patients had blunt aortic injuries (75% male, mean age, 45.9±16.3 years). The majority (82.1%, n=23/28) of these patients were involved in traffic accidents. The median ISS was 35.0 (interquartile range 21.0-41.0). The injuries were found in the ascending aorta (n=1, 3.6%) aortic arch (n=8, 28.6%) aortic isthmus (n=18, 64.3%), and descending aorta (n=1, 3.6%). The severity of aortic injuries on chest CT was categorized as intramural hematoma (n=1, 3.6%), dissection (n=3, 10.7%), transection (n=9, 32.2%), pseudoaneurysm (n=12, 42.8%), and rupture (n=3, 10.7%). Endovascular repair was performed in 71.4% of patients (45% within 24 hours), and two patients received surgical management. The mortality rate was 25% (n=7). Conclusions: Traumatic thoracic aortic injuries are life-threatening. In our experience, however, if there is no rupture and extravasation from an aortic injury, resuscitation and stabilization of vital signs are more important than an intervention for an aortic injury in patients with multiple traumas. Further study is required to optimize the timing of the intervention and explore management strategies for blunt thoracic aortic injuries in severe trauma patients needing resuscitation.

• Journal of Korean Biological Nursing Science
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• 제23권2호
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• pp.138-150
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• 2021

Purpose: This retrospective study aimed to investigate nursing interventions in patients with severe thoracic injury in trauma bay of a regional trauma center. Methods: Of the 1,780 patients admitted to the trauma bay of a regional trauma center in a university hospital in the Gyeonggi Province between January 1, 2019 and December 31, 2019, 120 adult patients with severe thoracic injury who met the inclusion criteria were enrolled. Participants' clinical characteristics and nursing interventions were collected from electronic medical records after receiving ethical approval. Nursing interventions were classified using the terminology in the Nursing Intervention Classification. Results: The mean age of participants was 52.25 years and 72.5% of participants were male. The main areas of thoracic injury included lung parenchyma and pleura (95.8%). The mean Abbreviated Injury Scale (AIS) for thoracic injury was 3.13 and the mean Injury Severity Score (ISS) was 17.81. Fluid resuscitation, invasive hemodynamic monitoring, chest tube care, respiratory monitoring, artificial airway management, gastrointestinal tube care, mechanical ventilation management: airway insertion and stabilization, blood product administration, allergy management, and surgical preparation were performed significantly more frequently in thoracic injury patients with unstable vital signs or a higher AIS score. Conclusion: This study is significant as it investigated the types of nursing interventions given to patients with severe thoracic injury in the trauma bay. These results would contribute to developing more detailed educational materials for initial nursing interventions in trauma bay.

• International Journal of Vascular Biomedical Engineering
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• 제2권2호
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• pp.10-15
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• 2004

Purpose: In the treatment of aortic aneurysm, endovascular stent-graft application has become an established method of treatment. To observe the outcomes of the procedure as the size change of aneurysm in relation with endoleak, a retrospective analysis was done for the consecutive cases who undertook the procedure. Materials & Method: Stent-graft was applied to the aortic aneurysm in 33 patients. The location of the aneurysm was thoracic in 11 patients and abdominal in 22 patients. CT angiographic was done for the follow-up evaluation to analyze the aneurysm size and the presence of endoleak. Results: Technical success rate was 97% (32/33). The primary success rate without endoleak was 84% (28/33). The secondary success was 90% (30/33). During the follow-up period of 3 months to 7years and 6months in 26 patients, a secondary endoleak developed in 5 cases. Post-implantation syndrome developed in 17 cases (51%). Among the 14 cases with follow-up imaging data for size, endoleak was negative in 10 cases. The aneurysm decreased in 5 cases, stable in size in 4 cases and enlarged in one case (10%).Among the 4 cases with endoleak positive, the aneurysm enlarged in two cases (50%). Conclusion: In the stent-graft application for aortic aneurysm, there is high chance of decrease of aneurysm size in those cases with endoleak negative. However, the aneurysm may increase and eventually rupture in the cases with en do leak positive. Close observation with CT angiography is necessary for the evaluation for the presence of endoleak and size change.

• Korean Journal of Radiology
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• 제22권6호
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• pp.890-900
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• 2021

Objective: To identify the association between morphological and functional characteristics of the bicuspid aortic valve (BAV) and bicuspid aortopathy and to identify the determinants of aortic dilatation using transthoracic echocardiography (TTE) and cardiac computed tomography (CCT). Materials and Methods: This study included 312 subjects (mean [SD] age, 52.7 [14.3] years; 227 males [72.8%]) who underwent TTE and CCT. The BAVs were classified by anterior-posterior (BAV-AP) or right-left (BAV-RL) orientation of the cusps and divided according to the presence (raphe+) or absence of a raphe (raphe-) based on the CCT and intraoperative findings. The dimensions of the sinus of Valsalva and the proximal ascending aorta were measured by CCT. We assessed the determinants of aortic root and proximal ascending aortic dilatation (size index > 2.1 cm/m²) by Univariable and multivariable logistic regression analyses. Results: Of the 312 patients, BAV-AP was present in 188 patients (60.3%), and 185 patients (59.3%) were raphe+. Moderate-to-severe aortic stenosis (AS) was the most common hemodynamic abnormality (54.8%). The most common type of aortopathy was the combined dilated root and mid-ascending aortic phenotype (62.5%). On multivariable analysis, age and AS severity were significantly associated with aortic root dilatation (p < 0.05), and age, sex, and AS severity were significantly associated with ascending aortic dilatation (p < 0.05). However, the orientation of the cusps, presence of a raphe, and severity of aortic regurgitation were not associated with aortic root and ascending aortic dilatation. Conclusion: BAV morphological characteristics were not determinants of aortic dilatation. Age, sex, and AS severity were predictors of bicuspid aortopathy. Therefore, age, sex, and AS severity, rather than valve morphology, need to be considered when planning treatment for BAV patients.

• Journal of Yeungnam Medical Science
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• 제40권4호
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• pp.448-453
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• 2023

Takayasu arteritis (TA) is a disease that causes inflammation and stenosis of medium to large blood vessels. We report a case of a 50-year-old female patient with newly developed hypertension, syncope, and claudication of the extremities. Total occlusion of the left subclavian artery at the origin was found and significant stenosis of the right common iliac artery was revealed by hemodynamic analysis. She was successfully treated with percutaneous angioplasty for multiple peripheral arterial diseases and was finally diagnosed with TA. In consultation with a rheumatologist, medical treatment for TA was initiated, the patient's hypertension disappeared, and her claudication symptoms improved.

• Journal of Cardiovascular Imaging
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• 제30권1호
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• pp.25-34
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• 2022

BACKGROUND: The purpose of this study was to assess the utility of a handheld device (HH) used during common daily practice and its agreement with the results of a standard echocardiography study (STD) performed by experienced sonographers and echocardiographer. METHODS: A prospective follow-up was conducted in an adult outpatient echocardiography clinic. Experienced sonographers performed the STD and an experienced echocardiographer performed the HH. STD included 2-dimensional images, Doppler and hemodynamics analysis. Hemodynamic assessment was not performed with the HH device because the HH does not include such technology. The images were interpreted by blinded echocardiographers, and the agreement between the reports was analyzed. RESULTS: A total of 108 patients were included; and the concordance for left ventricle (LV) ejection fraction (EF), wall motion score index, LV and right ventricle (RV) function, RV size, and mitral and aortic stenosis was excellent with κ values greater than 0.80. Wall motion abnormalities had good concordance (κ value 0.78). The agreement for LV hypertrophy, mitral and aortic regurgitation was moderate, and tricuspid and pulmonary regurgitation agreements were low (κ values of 0.26 and 0.25, respectively). CONCLUSIONS: In a daily practice scenario with experienced hands, HH demonstrated good correlation for most echocardiography indications, such as ventricular size and function assessment and stenosis valve lesion analyses.