• Journal of Chest Surgery
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• 제36권9호
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• pp.659-665
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• 2003

심폐바이패스를 사용하지 않는 관상동맥우회술에서 골격화된(skeletonized) 양측 내흉동맥 이외에 골격화된 우위대망동맥을 함께 사용한 환자들에서 수술 직후와 1년째의 성적을 비교하였다. 대상 및 방법: 1999년 8월부터 2001년 12월까지 서울대학교병원 흉부외과에서 골격화된 양측 내흉동맥과 우위대망동맥을 이용하여 시행한 103예의 관상동맥우회수술을 대상으로 하였다 이중 우위대망동맥을 유근이식편(in situ graft)으로 사용한 것이 88예, 근위부를 다른 혈관 도관에 연결(composite graft)하여 사용한 것이 10예, 대동맥에 연결(free graft)하여 사용한 것이 5예로 각각의 경우 수술 직후와 1년후 혈관조영검사를 통해 도관의 기능을 평가하였다. 결과: 평균 문합수는 3.8$\pm$0.7개였고 수술 직전 측정한 도관의 자유혈류량(free flow (ml/rnin))은 우위대망동맥이 130$\pm$95 ml/min로 좌내흉동맥(107$\pm$55 ml/min)과 우내흉동맥(113$\pm$57 ml/min)에 비해 유의하게 많았다(p<0.05). 수술 후 100명(97.1%)의 환자에게 평균 1.3$\pm$0.8일째에 혈관 조영 검사를 시행하였는데 내흉동맥은 98.6% (272/276),우위대망동맥은 97.0% (97/100)의 개통률을 보였다(p=ns). 퇴원 후에 평균 12.4$\pm$3.7개월째에 다시 88명(85.4%)의 환자에서 혈관 조영 검사를 시행하였다 개통률은 내흉동맥과 우위대망동맥이 각각 95.9%(234/244), 88.6%(78/88)로 내흉동맥이 조금 우세하였지만 통계적 유의성은 없었다(p=0.07). 우위대망동맥과 자신의 관상동맥 사이 혈류경쟁(flow competition)의 소견은 수술 직후에 5예, 1년 뒤에 7예에서 관찰되었는데 TTFM (transit time flow measurement)을 수술 중에 시행하여 혈류경쟁이 의심되는 경우에서 교정을 시행한 이후에는 각각 1예와 2예로 유의하게 줄어듦을 관찰할 수 있었다. 결론: 우위대망동맥은 내흉동맥에 이어 비교적 안전하게 사용할 수 있는 제3의 동맥 도관이며, 수술 중 혈류 측정, 대상 혈관의 정확한 수술 전 평가 등을 통해 중장기 개통률을 향상시킬 수 있다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권3호
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• pp.397-418
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• 1994

Microvascular surgery has been widely used in the clinical field of replantation and reconstructive surgery. Since the last 20 years, microsurgical techniques and instruments have been rapidly developed and the success rate is remarkably increased. But thrombotic occlusion of vessels remains the major reason for clinical failure. The change of vessel wall is the most important factor in thrombus formation. If we can reduce the traumatic changes in the vessel walls during surgery, the success rate can be markedly increased. For this study, femoral arteries and veins of 36 Sprague-Dawley rats with average weights of 300gm were used. The author observed the histological changes and healing process in the anastomostic site after 1 hour, 24 hours, 1, 2, 3 and 4 weeks under light microscopy and scanning electron microscopy. The results were as follows : 1. The patency rate was 100% in femoral arteries and 85% in femoral vein. 2. At the early stages after microvascular anastomosis, the loss of endothelial cell in the vessel walls was observed in the wide area including anastomotic site. In scanning electron microscopic finding the anastomotic site was covered with much fibrin, many red blood cells and some platelets. 3. At 1st week, new endothelial cells were formed toward anastomotic site and at 3rd week, the anastomotic site was completely covered by new endothelial cells. At 4th week, the complete endothelialization over the threads was observed. 4. The media extended from the anastomotic site toward the end of the specimen. At later stages, the extent of media necrosis was markedly decreased. But the media necrosis of anastomotic site was not regenerated till 4th week. 5. Intimal hyperplasia appeared at 1st week and increased till 4th week. The layer consisted of endothelialization the most luminal layers and smooth muscle in the deeper layers. But in veins, the response was less pronounced than in arteries. 6. Foreign body granuloma remained during 4 weeks and aneurysm was observed at 3rd week in artery. In aneurismal wall, media necrosis, loss of elastic lamina and intimal hyperplasia were seen.

• Archives of Plastic Surgery
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• 제40권3호
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• pp.214-219
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• 2013

Background We established the Microvascular Research Center Training Program (MRCP) to help trainee surgeons acquire and develop microsurgical skills. Medical students were recruited to undergo the MRCP to assess the effectiveness of the MRCP for trainee surgeons. Methods Twenty-two medical students with no prior microsurgical experience, who completed the course from 2005 to 2012, were included. The MRCP comprises 5 stages of training, each with specific passing requirements. Stages 1 and 2 involve anastomosing silicone tubes and blood vessels of chicken carcasses, respectively, within 20 minutes. Stage 3 involves anastomosing the femoral artery and vein of live rats with a 1-day patency rate of >80%. Stage 4 requires replantation of free superficial inferior epigastric artery flaps in rats with a 7-day success rate of >80%. Stage 5 involves successful completion of one case of rat replantation/transplantation. We calculated the passing rate for each stage and recorded the number of anastomoses required to pass stages 3 and 4. Results The passing rates were 100% (22/22) for stages 1 and 2, 86.4% (19/22) for stage 3, 59.1% (13/22) for stage 4, and 55.0% (11/20) for stage 5. The number of anastomoses performed was $17.2{\pm}12.2$ in stage 3 and $11.3{\pm}8.1$ in stage 4. Conclusions Majority of the medical students who undertook the MRCP acquired basic microsurgical skills. Thus, we conclude that the MRCP is an effective microsurgery training program for trainee surgeons.

• 대한의용생체공학회:의공학회지
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• 제17권3호
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• pp.337-346
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• 1996

The patency of small size vascular grafts is poor, and the blood flow characteristics in the artery graft anastomosis are suspected as one of the important factors influencing intimal hyperplasia. Disturbed flow patterns caused by sixte and compliance mismatch generate unfavorable flow environment which promotes intimal thickening. Tapered vascular yuts are suggested in order to reduce sudden expansion near the anastomosis. The photochromic flow visualization method is used to measure the flout fields in the end-to-end anastomosis model under the carotid and femoral artery flow wave form. The results show that flow disturbance near the anastomosis is diminished in the tapered grafts comparing to the tubular graft. As the divergent ang1e decreases, we can reduce the low and oscillatory wall shear stress zone which is prone to intimal hyperplasia. The flow wave form effects the wall shear rate dis- tribution significantly. The steep deceleration and back flow in the femoral flow wAve form cause low mean wall shear rate and high oscillatory shear index.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제12권1호
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• pp.72-81
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• 1990

Because failure of microvascular flap grafting has sometimes been attributed to vascular obstruction in the anastomotic site, this study investigated the healing process after microvascular anastomoses. The healing process of anastomotic sites were observed by the use of the light and the scanning electron microscope after microvascular anastomoses of the right common carotid artery in rats. The experimental animals were sacrificed on the 4th day, 1st, 2nd, 4th and 6th week. Throughout the whole experimental period, arterial patency rate was 78% (11/14). At the early stage, it was possible to recognize histologically disappearance of endothelial cell and rupture of part of the media. Subintimal hyperplasia and the growth of media appeared around the suture line at the 2nd week. Endothelial cell regeneration occurred and the depth of vessel wall was normalized at the 4th week. By the scanning electron microscope, at the early stage, the anastomotic site was covered with many platelets, red blood cells, fibrins and macrophages. At the 4th week, the insertion site of the thread was completely covered with normal endothelial cells which were parallel to longitudinal axis of vessels and complete reendothelialization over the anastomotic site seemed to take about 6th week.

• Clinical and Experimental Reproductive Medicine
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• 제23권1호
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• pp.67-71
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• 1996

During a 2-year period microsurgical vasovasostomies using permanent silicone stent(c-shaped stent with 0.6mm slit, 5mm in length, 0.8mm in outer diameter, 0.5mm in inner diameter) were performed in 30 patients for vasectomy revesal. The stent-assisted vasovasostomy(SVV) was intended to decrease the technical demand, the time requirement and the occurrence of reobstruction due to postoperative stricture. The effectiveness of the permanent silicone stent for vasovasostomy was compared with that of microsurgical two-layered vasovasostomy(VV). Sperms were present in all the ejaculates of the 25 men on semen analysis 1-2 months after SVV. Pregnancy occurred in 10 of 22 couples(45.5%) during 2-24 months of follow-up and it took 4-10 months(average 7.2 months) to get pregnant. Average operation time for the VV was 150 minutes and that for the SVV 125 minutes. Among 12 men who had sperms in the ejaculates 1-2 months after SVV, 4 revealed azoospermia 3-17 months postoperatively. Among the 4 patients with postoperative azoospermia, 2 underwent reoperation. On histopathologic examination, previously anastomsed sites showed obliterated lumen of the stent and strictures of vas proximal and/or distal to the stents due to granulation tissues. In conclusion, the SVV was not more efficacious in terms of patency and pregnancy rate than the VV.

• Journal of Chest Surgery
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• 제35권12호
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• pp.898-901
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• 2002

관상동맥 우회술에서 동맥도관만을 사용하는 방법은 동맥편이 가진 도관개통률의 우수성 때문에 복재정맥을 혼합하여 사용하는 관상동맥 우회술에 비해 좋은 단기 성적은 물론이고, 향상된 장기 성적을 기대할 수 있다. 그러나 때때로 내흉동맥 또는 다른 동맥편들의 사용이 가능하지 않은 경우가 있고, 특히 당뇨환자에서 양측 내흉동맥의 사용은 술 후 종격동염을 비롯한 합병증을 우려하여 사용이 꺼려지기도 한다. 또한 관상동맥 우회술의 재수술의 경우에는 사용가능한 동맥편 수의 제한이 문제가 되는데 이러한 경우 대체동맥편으로서 흉배동맥을 사용할 수 있으며, 저자들은 흉배동맥을 사용하여 시행했던 3례의 관상동맥 우회술을 보고하고자 한다.

• Journal of Chest Surgery
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• 제23권2호
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• pp.333-341
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• 1990

aortoiliac pattern, Group II; femoropopliteal pattern and Group g; tibioperoneal pattern. A majority of patients belonged to group I [27 cases], 8 patients came under group II .and none in group g. Thirty patients underwent bypass operation with autogenous saphenous vein or synthetic graft with or without concomitant lumbar sympathectomy. Remaining 5 patients were operated on with sympathectomy only, Bypass procedures were anatomic bypass in 22 cases: aortoiliac artery bypass in 11 cases, femoropopliteal artery bypass in 10 cases, sequential femoropopliteal artery bypass in one case and extra-anatomic bypass in 8 cases, axillary-bifemoral artery bypass in one case and femorofemoral artery bypass in 7 cases. Postoperative complications which mainly composed of superficial wound infection[5 cases] which were treated without any significant sequel in all cases and thrombosis[2 cases]. Three patients died whose causes of death were acute renal failure in 2 cases and myocardial infarction in other, The overall patency, rate was 70Zo in 5 years. In conclusion, the clinical pattern and operative outcome were similar to he western pattern and all cases of death did not related to operative procedures and ischemic symptoms were relieved by bypass operations except several cases. I think and recommend that all patients suffering chronic arterial insufficiency by atherosclerosis obliterans ought to be managed with urgent and adequate operative procedure.

• 한국가시화정보학회지
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• 제14권1호
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• pp.33-39
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• 2016

Radio-cephalic arteriovenous fistula(RC-AVF) is the most recommended operation of achieving access for hemodialysis. However, it has high rates of early failure depending on the many haemodynamic conditions. To increase RC-AVF patency rate, many researches were performed by in-vitro experiment via artificial vessel and blood analogue fluid, and there were conflicting opinions about whether the non-Newtonian properties of blood have an influence on the flow in large arteries. To investigate the influence of viscoelasticity of blood within the RC-AVF, we fabricated three dimensional artificial RC-AVF and two kinds of blood analogue fluid. The velocity field of two fluids within the vessel were measured by micro-particle velocimetry(m-PIV) and compared with each other. The velocity profiles of both fluids for systolic phase were matched well while those for diastolic phase did not correspond. Therefore, it is desired to use non-newtonian fluid for in-vitro experiment of RC-AVF.

• Journal of Chest Surgery
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• 제49권6호
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• pp.485-488
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• 2016

Different suture techniques have been used for anastomosis in coronary artery bypass graft surgery. Bypass surgery may be difficult for patients who have small coronary arteries or marked size discrepancies between target coronary arteries and grafts. For proximal and distal anastomoses, three continuous stitches are first placed in the heel and toe of the small coronary arteries; for sequential anastomosis, an interrupted eight-stitch technique is used. We applied these anastomotic suture techniques in patients requiring coronary artery bypass graft surgery, achieving an early angiographic patency rate of 100%.