• Journal of Chest Surgery
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• 제52권1호
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• pp.9-15
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• 2019

Background: Although aortic valve repair can reduce prosthesis-related complications, rheumatic aortic regurgitation (AR) caused by leaflet restriction is a significant risk factor for recurrent AR. In this study, we evaluated the long-term results of the leaflet extension technique for rheumatic AR. Methods: Between 1995 and 2016, 33 patients underwent aortic valve repair using the leaflet extension technique with autologous pericardium for rheumatic pure AR. Twenty patients had severe AR and 9 had combined moderate or greater mitral regurgitation. Their mean age was $32.2{\pm}13.9$ years. The mean follow-up duration was $18.3{\pm}5.8$ years. Results: There were no cases of operative mortality, but postoperative complications occurred in 5 patients. Overall survival at 10 and 20 years was 93.5% and 87.1%, respectively. There were no thromboembolic cerebrovascular events, but 4 late deaths occurred, as well as a bleeding event in 1 patient who was taking warfarin. Twelve patients underwent aortic valve reoperation. The mean interval to reoperation was $13.1{\pm}6.1$ years. Freedom from reoperation at 10 and 20 years was 96.7% and 66.6%, respectively. Conclusion: The long-term results of the leaflet extension technique showed acceptable durability and a low incidence of thromboembolic events and bleeding. The leaflet extension technique may be a good option for young patients with rheumatic AR.

• Journal of Cardiovascular Imaging
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• 제31권1호
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• pp.18-23
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• 2023

BACKGROUND: Three-dimensional (3D) transesophageal echocardiogram (TEE) is the gold standard for the diagnosis of degenerative mitral regurgitation (dMR) and preoperative planning for transcatheter mitral valve repair (TMVr). TEE is an invasive modality requiring anesthesia and esophageal intubation. The severe acute respiratory syndrome coronavirus 2 pandemic has limited the number of elective invasive procedures. Multi-detector computed tomographic angiography (MDCT) provides high-resolution images and 3D reconstructions to assess complex mitral anatomy. We hypothesized that MDCT would reveal similar information to TEE relevant to TMVr, thus deferring the need for a preoperative TEE in certain situations like during a pandemic. METHODS: We retrospectively analyzed data on patients who underwent or were evaluated for TMVr for dMR with preoperative MDCT and TEE between 2017 and 2019. Two TEE and 2 MDCT readers, blinded to patient outcome, analyzed: leaflet pathology (flail, degenerative, mixed), leaflet location, mitral valve area (MVA), flail width/gap, anterior-posterior (AP) and commissural diameters, posterior leaflet length, leaflet thickness, presence of mitral valve cleft and degree of mitral annular calcification (MAC). RESULTS: A total of 22 (out of 87) patients had preoperative MDCT. MDCT correctly identified the leaflet pathology in 77% (17/22), flail leaflet in 91% (10/11), MAC degree in 91% (10/11) and the dysfunctional leaflet location in 95% (21/22) of patients. There were no differences in the measurements for MVA, flail width, commissural or AP diameter, posterior leaflet length, and leaflet thickness. MDCT overestimated the measurements of flail gap. CONCLUSIONS: For preoperative TMVr planning, MDCT provided similar measurements to TEE in our study.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.504-512
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• 2002

Bileaflet mechanical valves have the complications such as hemolytic and thromboembolic events, leaflet damage, and leaflet break. These complications are related with the fluid velocity and shear stress characteristics of mechanical heart valves. This fact makes clear the importance of determining the fluid velocity and shear stress characteristics of mechanical heart valves, and requires a detailed understanding of these system properties and further substantial research. The first aim of current study is to introduce fluid-structure interaction method for calculation of unsteady and three-dimensional blood flow through bileaflet valve and leaflet behavior interacted with its flow, and to overcome the shortness of previous studies, where the leaflet motion has been ignored or simplified, by using FSI method. To accomplish this goal, a finite volume computational fluid dynamics code and a finite element structure dynamics code have been used concurrently to solve the flow and structure equations, respectively, to investigate the interaction between the blood flow and leaflet. Physiologic ventricular and aortic pressure waveforms were prescribed as flow boundary conditions. The interaction of aortic flow and valve motion were computed.

• Journal of Chest Surgery
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• 제40권12호
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• pp.859-862
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• 2007

심장 판막엽에 발생하는 혈관종은 극히 드문 질환으로 최근까지 문헌에 보고된 것은 총 5례가 전부이며 아직까지 국내문헌에는 보고된 바가 없다. 건강하던 46세 여자가 갑자기 발생한 좌측 안면마비와 수부 감각이상을 주소로 내원하였다. 신경학적 검사에서는 이상 소견이 없었으며 심장초음파에서 승모판막 전엽에 위치한 종괴가 발견되어 종괴를 포함한 승모판막 전엽의 일부를 절제한 후 자가심낭을 이용하여 승모판막성형을 시행하였다. 병리조직 검사상 승모판막 전엽에 발생한 혈관종으로 판명되어 문헌고찰과 함께 보고하는 바이다.

• 펄프종이기술
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• 제45권6호
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• pp.55-63
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• 2013

To offer a basic information for the fibers of commercial leaflets, authors examined and analyzed the distribution, size, and printing types of leaflets sandwiched in the newspaper. The number of different leaflet size were almost 30 in two years including B5 ($182{\times}257mm$), A4 ($210{\times}297mm$), B4, ($257{\times}364mm$), A3 ($297{\times}420mm$), and large flyers such as $545{\times}395mm$, and $790{\times}550mm$. The number of different leaflets size were 25 in 2011, which was reduced to 15 in 2012. Both the number and amount of the leaflets were reduced. The high quality leaflets were issued and distributed in the corporate sector and the leaflets issued in other sectors such as shopkeeping, restaurant business, educational institutions were one-sided leaflets printed on single side of the paper. Compared to the previous year, large stores showed the increased number of leaflets but the number of leaflets from restaurant business and educational institutions and building trade were decreased.

• Journal of Chest Surgery
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• 제18권1호
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• pp.92-96
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• 1985

A cleft in the anterior mitral valve leaflet is commonly associated with atrioventricular septal defects, but may occur as an isolated phenomenon. The cleft mitral valve can cause regurgitation, and surgical treatment of the cleft leaflet should conserve the existing valve if possible. But if satisfactory hemodynamic security cannot be obtained with a reconstructive procedure, the valve should be replaced. We present one case of an isolated cleft in the anterior mitral valve leaflet. The patient showed marked mitral regurgitation in the preoperative left ventriculogram. We managed him successfully by interrupted suture repair of the cleft, and he was discharged uneventfully.

• Journal of Chest Surgery
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• 제37권4호
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• pp.373-375
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• 2004

Edwards Duromedics 기계판막은 잦은 판엽 이탈로 인해 1988년 5월부터 판매가 중지된 판막으로 국내에서는 현재까지 2예의 판엽 이탈이 보고되었다. 본원에서는 Edwards Duromedics 기계판막을 이용하여 승모판치환술을 받은 환자에서 발생한 판엽 이탈을 경험하였기에 증례 보고하는 바이다

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 1998년도 가을 학술발표대회 논문집 디자인 학 연구
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• pp.80-81
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• 1998

• 한국작물학회지
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• 제37권4호
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• pp.313-319
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• 1992

토양수분 부족이 콩식물체의 엽운동, 광합성능, 증산량, 수량 및 관련 형질에 미치는 영향을 조사하기 위해서, '단엽콩', '방사콩', '보광콩', '무한콩'을 비닐하우스 내에 폿트 재배에서 2주간 단수처리하여 실험을 하였다. 1. 광합성능은 광량(0.887$^{**}$ ), 기공전도율(0.788$^{**}$ ) 및 엽온(0.744$^{**}$)과 고도의 유의적인 정 상관이 있었다. 2. 1일중 광량과 온도가 증가함에 따라 콩의 복엽중 중앙의 소엽은 측렬의 소엽에 비해 더 빨리 엽운동이 시작되고 광합성능이 높은 반면에 수광량, 엽온은 다소 낮았다. 3. 한발구에 비해 관수구의 광량은 358 umole $m^{-2}$ $s^{-1}$, 기공전도율은 0.2 mole $m^{-2}$ $s^{-1}$, 엽온은 9$^{\circ}C$, 증산량 3.7 mole $m^{-2}$ , 광합성능은 8.5 $CO_2$, $\mu$mole $m^{-2}$ $s^{-1}$이 각각 높았다. 4. 관수구에 비해 한발구의 수량 및 관련 형질이 다양하게 감소되었다 ; 개체당 건물중 8%, 개체당 근류중 7%, 근중 14%, 간장 3%, 분지수 7%, 경태 8%, 개체당 협수 17%, 개체당 립중 17%가 각각 감소되었다.

• 한국임상약학회지
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• 제26권3호
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• pp.254-263
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• 2016

Objective: Written information could be helpful for senior population to adhere to complex medication therapies, but must be well prepared and empirically assessed to achieve such end. We purposed to develop a drug information leaflet for senior citizens by applying 'performance-based user-testing.' Methods: We employed a user-testing, a mixed method to figure difficulties out with patients' leaflets from the user perspective. The cycle made of test and revision can be repeated as necessary. We recruited senior citizens with age of 65 or above who were taking antihypertensive medications at the point of participating and excluded the elderly who suffered illiteracy. We firstly rectified a drug information leaflet of antihypertensive medications for the general public distributed by the Korean authority based on focus group interviews (9 participants). The revised leaflets were tested four times with 8~12 participants in each round (40 seniors in total). We targeted to develop a leaflet which more than 80% of participants understood 10 key information. Main outcomes measures were to be able to find information and be able to understand information. This study was approved by the Yeungnam University Research Ethics Committee. Results: Focus group interviews identified difficulties with small font of words, professional language, long information, and a poor structure. The leaflet was revised and in the first round questionnaire found problems with 4/10 information points; interviews disclosed all but one (normal blood pressure range) were ill-understood. The second round questionnaire and interview found fewer problems but the comprehensiveness of participants was still poor in several points. For the third and fourth rounds we revised the leaflets in the individual-targeted manner. Finally, the fourth round showed all key information found and understood by at least 80% of participants except one question about drug name. Conclusion: The drug leaflets need to be developed in a personalized mode for the seniors. There was a limit for Korean seniors to understand nonproprietary name of their drugs because they used to producers' trade names which the Korean health system predominantly works with.