• Macromolecular Research
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• 제17권11호
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• pp.825-828
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• 2009

• Journal of Chest Surgery
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• 제39권8호
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• pp.611-618
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• 2006

배경 : 관상동맥협착증에 동반되는 중등도의 만성 허혈성 승모판막 폐쇄부전의 경우 승모판막에 대한 수술적 치료가 필요한지에 대하여 많은 논란이 있다. 저자는 이러한 환자들을 대상으로 임상 결과를 알보고자 하였다. 대상 및 방법: 1992년 1월부터 2005년 2월까지 관상동맥 우회로 조성술을 시행 받은 환자 중 중등도의 허혈성 승모판막 폐쇄부전이 있던 44명의 환자를 대상으로 후향적 연구를 시행하였다. 승모판막 수술을 시행 받은 환자는 20명이었고 (group 1) 승모판막 수술을 시행 받지 않은 환자는 24명이었다(group 2). Group 1에서 체외심폐순환 시간이 유의하게 걸었으나 (p<0.01) 나이, 성별, 수술 전 심박출 계수, 문합한 혈관의 수 등 다른 인자는 두 group 간에 차이가 없었다. 수술 후 심초음파 시행 시기는 평균 $21.2{\pm}28.0$개월이었고 평균 추적관찰기간은 $30.1{\pm}29.6$개월이었다. 결과: 두 group 간에 수술 사망률은 유의한 차이가 없었다(group 1 vs group 2, 15.0% vs 8.3%, p=0.493). Group 1에서 group 2보다 승모판막 폐쇄부전도 ${(0.81{\pm}0.91\;vs\;1.50{\pm}0.05,\;p=0.046)}$, 폐쇄부전 정도의 경감 ${(1.75{\pm}0.93\;vs\;0.70{\pm}1.26,\;p=0.009)}$에서 차이를 보였다. 수술 후 섬박출 계수 ${(34.1{\pm}11.4%\;vs\;41.6{\pm}12.9%)}$, 좌심실 수축기 용적 ${(118.2{\pm}63.9\;ml%\;vs\;85.6{\pm}281\;ml)}$, NYHA functional class ${(2.1{\pm}0.2\;vs\;2.4{\pm}1.2)}$는 차이가 없었고, 5년에서의 생존율도 유의한 차이를 보이지 않았다${(85{\pm}8%\;vs\;82{\pm}8%)}$. 수술 사망에 대한 유의한 위험 인자는 없었으며 만기 사망에 대한 위험인자는 수술 전 심방 세동이 있던 경우(p=0.042)였고 승모판막 수술의 유무는 만기 사망과 유의한 관계를 보이지 않았다. 결론: 중등도의 승모판막 폐쇄부전이 있는 경우 승모판막을 수술하는 것이 수술 후 폐쇄부전의 정도가 의미 있게 감소하였으나 생존율 및 심장 기능에 있어서는 별 차이가 없었다. 이러한 환자에서 승모판막 수술의 필요성 및 심실 기능의 향상을 위한 좀 더 전향적인 연구가 필요하리라 생각된다.

• 한국농공학회지
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• 제36권1호
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• pp.54-62
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• 1994

The expanding technique of the Stochastic Finite Element Method(SFEM) is proposed in this paper for adapting direct integration methods in stochastical dynamic analysis of structures. Grafting the direct integration methods and the SFEM together, one can deal with nonlinear structures and nonstationary process problems without any restriction. The stochastical central diffrence and stochastic Houbolt methods are introduced to show the expanding technique, and their adaptabilities are discussed. Results computed by the proposed method (the Stochastic Finite Element Method in Dynamics: SFEMD) for two degree-of-free- dom system are compared with those obtained by Monte Carlo Simulation.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.245-248
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• 1997

Operative interventions for the management of osteonecrosis of the femoral head (ONFH) include core drilling, with or without vascularized fibular bone grafting. Nevertheless, their clinical results have not been consistently satisfactory. Recently, a new surgical procedure that incorporates cementation with polymethylmethacrylate (PMMA) after core drilling has been tried clinically. In this study, a biomechanical analysis using a finite element method(FEM) was undertaken to evaluate surgical methods and their underlying surgical parameter. Our finite element models included five types. They were (1) normal model (Type I), (2) necrotic model (Type II), (3) core decompressed model (Type III). (4) fibular bone grafted model (Type IV), and (5) cemented with PMMA model (Type V). The geometric dimensions of the femur were based on digitized CT-scan data of a normal person. Various physiological loading conditions and surgical penetration depths by the core were used as mechanical variables to study their biomechanical contributions in stress transfer within the femoral head region. In addition. the peak von Mises stress(PVMS) within the necrotic cancellous bone of the femoral head was obtained. The fibular bone grafted method and cementation method provided optimal stress transfer behaviors. Here. substantial increase in the low stress level was observed when the penetration depth was extended to 0mm and 5mm from the subchondral region. Moreover, significant decrease in PVMS due to surgery was observed in the fibular bone grafted method and the cementation method when the penetration depths were extended up to 0 and 5mm from the subchondral region. The drop in PVMS was greater during toe-off than during heel-strike (57% vs. 28% in Type IV and 49% vs. 22% in Type V). Both the vascularized fibular bone grafting method (Type IV) and the new PMMA technique (Type V) appear to be very effective in providing good stress transfer and reducing the peak Von-Mises stress within the necrotic region. Overall results show that fibular bone grafting and cementation methods are quite similar. In light of above results, the new cementation method appears to be a promising surgical alternative or the treatment of ONFH. The use of PMMA for the core can be less prone to surgical complication as opposed to preparation of fibular bone graft and can achieve more immediate fixation between the core and the surrounding region.

• Journal of Chest Surgery
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• 제39권8호
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• pp.598-603
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• 2006

배경 : 경막외 마취를 이용하여 의식 있는 환자에서 관상동맥우회술을 시행하는 경우 기계 환기 및 전신 마취에 의한 합병증을 피할 수 있는 장점들이 기대된다. 대상 및 방법: 2005년 4월부터 2005년 9월까지 12명의 환자를 대상으로 상흉부 경막외 마취를 이용하여 의식이 있는 상태에서 심폐바이패스를 사용하지 않는 관상동맥우회술을 시행하였다. 1명은 여자였고 11명은 남자였으며 평균 연령은 $66{\pm}6$세였다. 정중 흉골 절개술을 시행한 후 동맥도관만을 이용하여 관상동맥우회술을 시행하였다. 결과: 평균 원위부 문합수는 ${1.8{\pm}0.9\;(1{\sim}3)}$이었으며, 수술사망 예는 없었다. 수술을 시행하는 동안 모두 8 명의 환자에서 기흉이 발생하였으며, 수술 중 기흉 (n =3), 복부내장의 팽창 (n=1), 흉관 삽입 후 발생한 혈흉 (n=1) 등의 원인으로 12 명 중 5 명의 환자에서는 기관 삽관 후 전신마취로 전환이 필요하였다. 모든 환자에서 수술 후 $1.2{\pm}0.6$일째에 관상동맥조명술을 시행하였으며, 모든 우회도관은 개통되어 있었다. 결론: 본원의 초기 경험을 통해 전신 마취를 하지 않고 의식이 있는 상태에서 심폐바이패스를 사용하지 않는 관상동맥우회술을 시행하는 것이 가능함을 확인할 수 있었다 . 이러한 수술 방법의 적응증 및 제한점에 대해서는 향후 경험을 통한 추가적인 연구가 필요할 것으로 생각된다.

• Archives of Plastic Surgery
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• 제44권3호
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• pp.188-193
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• 2017

Alveolar cleft is a tornado-shaped bone defect in the maxillary arch. The treatment goals for alveolar cleft are stabilization and provision of bone continuity to the maxillary arch, permitting support for tooth eruption, eliminating oronasal fistulas, providing an improved esthetic result, and improving speech. Treatment protocols vary in terms of the operative time, surgical techniques, and graft materials. Early approaches including boneless bone grafting (gingivoperiosteoplasty) and primary bone graft fell into disfavor because they impaired facial growth, and they remain controversial. Secondary bone graft (SBG) is not the most perfect method, but long-term follow-up has shown that the graft is absorbed to a lesser extent, does not impede facial growth, and supports other teeth. Accordingly, SBG in the mixed dentition phase (6-11 years) has become the preferred method of treatment. The most commonly used graft material is cancellous bone from the iliac crest. Recently, many researchers have investigated the use of allogeneic bone, artificial bone, and recombinant human bone morphogenetic protein, along with growth factors because of their ability to decrease donor-site morbidity. Further investigations of bone substitutes and additives will continue to be needed to increase their effectiveness and to reduce complications.

• Journal of Chest Surgery
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• 제32권8호
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• pp.709-714
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• 1999

배경: 관상동맥에 내흉동맥편과 복재정맥편을 동시에 문합할 때 두 이식편 사이에 생기는 혈압과 혈류의 차이 때문에 내경이 작은 내흉동맥편의 개존이 나빠질 수 있다. 이런 수술을 받은 환자에서 중단기적 임상 결과를 보고 특히 상경적인 혈류의 영향을 많이 받는 내흉동맥편의 개존 상태를 알고자 하였다. 대상 및 방법: 좌전하행지에 문합된 내흉동맥의 혈류가 충분하지 못하다고 판단된 14예의 환자에서 같은 관상동맥에 좌내흉동맥편과 복재정맥편을 동시에 문합하였다. 평균 33.5개월의 추적기간동안 증상이 재발한 경우, 좌내 흉동맥편의 혈류를 확인하고자 하는 경우, 수술 직후에 Q파를 보인 경우 등 6예에서 관상동맥 조영술을 시 행하였다. 결과: 복재정맥편과 내흉동맥편은 모두 개존되어 있었으며, 2예에서는 양측 균등한 혈류를 보인 반면, 다른 2예에서는 상경적인 혈류를 보였고 나머지 2예에서는 내흉동맥편이 개존되어 있었으나 관상동맥 으로 가는 혈류는 거의 없었다. 결론: 좌내흉동맥편을 좌전하행지에 문합하는 수술에서 복재정맥편을 부가 적으로 좌전하행지에 문합하는 경우에 수술 후 좌전하행지의 혈류를 충분히 유지할 수 있으며, 이러한 이중 문합이 내흉동맥편의 중단기적 개존에 영향을 미치지는 않을 것으로 생각된다.

• Macromolecular Research
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• 제10권5호
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• pp.291-295
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• 2002

Atomic force microscopy(AFM) was used to study the polyethylene(PE) surfaces grafted and immobilized with acrylic acid by Ar plasma treatment. The topographical images and parameters including RMS roughness and Rp-v value provided an appropriate means to characterize the surfaces. The plasma grafting and immobilization method were a useful tool for the preparation of surfaces with carboxyl group. However, the plasma immobilization method turned out to have a limitation to use as a means of preparation of PE surface with specific functionalities, due to ablation effect during the Ar plasma treatment process.

• Archives of Plastic Surgery
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• 제38권6호
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• pp.829-835
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• 2011

Purpose: The two major concerns in skin grafting are poor color match in the recipient site and the donor site morbidity. And, glabrous skin on the palmar aspect of the hands and plantar aspect of the feet attributes define the skin on the palm and fingers sole as functionally and aesthetically different from skin on other parts of the body. When there is a glabrous skin defect, it should be replaced with similar skin to restore function and aesthetics. The palmar crease areas were used to minimize these problems. The purpose of this study is to present the precise surgical technique of the full thickness skin graft using distal palmar and midpalmar creases for aesthetic better outcome for hand injuries. Methods: From May 2006 to April 2010, 10 patients with 11 defects underwent glabrous full thickness skin grafting of finger defects. Causes included seven machinery injuries, two secondary burn reconstructions, and one knife injury. Donor sites included ten glabrous full thickness skin graft from the distal palmar crease and one from the midpalmar crease. Results: Follow-up ranged from 3 months to 24 months. All glabrous skin grafts demonstrated complete taking the recipient sites and no incidence of the complete or partial loss. The donor site healed without complications, and there were no incidences of significant hypopigmantation, hyperpigmentation, or hypertrophic scarring. Conclusion: The important aspects of this method involve immediate return of glabrous skin to the defect site and restoration of the recipient site's crease by simple primary closure from adjacent skin. The glabrous skin of the palm provides the best tissue match for the reconstruction of the hands, but only a limited amount of tissue is available for this purpose. Full thickness skin grafting using palmar crease of the defects is the ideal way of reconstructing glabrous skin to restore both function and aesthetics and minimize donor site morbidity.

• Archives of Plastic Surgery
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• 제39권5호
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• pp.534-539
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• 2012

Background Autologous fat grafting evolved over the twentieth century to become a quick, safe, and reliable method for restoring volume. However, autologous fat grafts have some problems including uncertain viability of the grafted fat and a low rate of graft survival. To overcome the problems associated with autologous fat grafts, we used uncultured adipose tissue-derived stromal cell (stromal vascular fraction, SVF) assisted autologous fat grafting. Thus, the purpose of this study was to evaluate the effect of SVF in a clinical trial. Methods SVF cells were freshly isolated from half of the aspirated fat and were used in combination with the other half of the aspirated fat during the procedure. Between March 2007 and February 2008, a total of 9 SVF-assisted fat grafts were performed in 9 patients. The patients were followed for 12 weeks after treatment. Data collected at each follow-up visit included clinical examination of the graft site(s), photographs for historical comparison, and information from a patient questionnaire that measured the outcomes from the patient perspective. The photographs were evaluated by medical professionals. Results Scores of the left facial area grafted with adipose tissue mixed with SVF cells were significantly higher compared with those of the right facial area grafted with adipose tissue without SVF cells. There was no significant adverse effect. Conclusions The subjective patient satisfaction survey and surgeon survey showed that SVF-assisted fat grafting was a surgical procedure with superior results.