• 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.

• 대한의용생체공학회:의공학회지
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• 제13권4호
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• pp.313-322
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• 1992

A finite analytic(FA) numerical study was performed to determin'e flow dynamics in the vicinity of an end-to-end anastomosis. Experimental data of instantaneous lumen cross-section were used to simulate steady flow through an end-to-end anastomosis In order to solve the governing axisymmetric Wavier-Stokes equations. Wall shear stresses increased proximal to the anastomosis In flow from the Penrose tubing to the PTFE graft. In flow the PTFE graft to the Penrose tubing, low wall shear stresses were observed distal to the anastomosis. The present study suggests a correlation betweerl regions of low wall shear stress and the do velopment of pnastomotic neointimal fibrous hyperplasia(ANFH ) in end-to-end anastomoses.

• 대한의용생체공학회:의공학회지
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• 제6권2호
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• pp.9-12
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• 1985

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.139-144
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• 1981

Eighty four human maxillary first premolars were injected with china ink, decalcified, cleared and used in study, in vitro, to determine the number of root canals, the frequency and location of lateral canals, the frequency and location of transverse anastomoses, the curvature of root canals, the location of apical foramens, and the frequency of apical deltas. The results were as follows: 1. Most of the teeth demonstrated two canals, but 20.2% of the teeth were found to have one canal. 2. Of the 151 canals studied, 38.4% of the canals were found to have lateral canals and these ramifications were usually located in the apical third of the root. 3. Of the two root canals in one root, 35.7% of the canals were found to have transverse anastomoses and were usually located in the middle third of the root. 4. 15.2% of apical foramens were located directly on the root apex and 84.8% of them laterally, and 52.3% of canals showed distal curvature.

• 대한두개안면성형외과학회지
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• 제25권2호
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• pp.95-98
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• 2024

Scalp avulsion is a devastating injury. The best possible procedure is replantation. Several successful scalp replantations with anastomoses of several vessels in large defects have been reported. In this report, we present a case of replantation of a large scalp avulsion using revascularizing with only one artery and vein. Despite the initial signs of flap congestion, we could predict the survival of the replanted scalp and terminate the procedure after detecting good perfusion and washout with indocyanine green fluorescence imaging. The procedure was successful following the patient's recovery of sensory and sweating functions without complications such as flap necrosis or infection. Several important factors for successful scalp replantation with positive esthetic and functional outcomes were considered.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 2005년도 제44차 추계학술대회
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• pp.22-22
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• 2005

• Journal of Chest Surgery
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• 제25권11호
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• pp.1362-1368
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• 1992

Between March 1986 and November 1992, thirty-one patients with left main coronary artery stenosis[LMCAS, over 50% of cross sectional area] were revascularized at Seoul National University Hospital. The incidence of LMCAS was 20.8%[31/149]. The male:female ratio was 15:16. Age ranged from 39 to 70 years, with a mean age of 51 years. The anginal syndrome was composed of 23 unstable, 6 stable and 2 post-infarction angina preoperatively. There were sixteen isolated LMCAS, four ostial stenosis and eleven combined distal and /or right coronary artery stenosis. The degree of LMCAS was 50-74% in 21 patients[67.7%], 75-89% in one[3.6%] and 90-99% in 9[29.1%]. There was no case with 100% obstruction. Of the total patients with LMCAS, 11 patients received 4 distal anastomoses, another 11 patients had 3 distal anastomoses, and 8 patients needed 2 distal anastomoses. The overall operative mortality was 12.9%[4 /31], and the incidence of which was higher than the remaing group [6.8%, 8/118]. The causes of death were myocardial infarction[2 patients], ventricular arrhythmia[1 patient] and brain damage[1 patient]. All patients have been followed-up for average 28.9 months[1-76 months]. There was no late death. But one patients experinced anginal recurrence. In conclusion, making allowance for its notorious clinical results and relatively higher incidence in Korea, aggressive surgical techniques such as retrograce myocardial perfusion may be mandatory while we are in a learning phase.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권1호
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• pp.22-32
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• 2000

Purpose : Histopathologic observation was performed in order to determine which type of suture material is superior in microvascular anastomoses. Materials & Methods : The interrupted end to end anastomosis of the transected carotid arteries of 105 Sprague-Dawley rats, weighing 180 to 200g, were performed using 9-0 polypropylene ($Prolene^{TM}$, Ethicon, U.K.), 9-0 polyglactin 910 monofilament($Vicryl^{TM}$, Ethicon, U.K.), and 9-0 polyamide($Ethilon^{TM}$, Ethicon, U.K.) under intramuscular Ketamine and Xylazine anesthesia(5mg/100g). In all cases, 10 to 12 sutures were placed to complete the anastomoses. The specimens were obtained at 1, 2, 3 days, and 1, 2, 4 and 6 weeks after the surgery and prepared with H&E and Van-Gieson stains and investigated the histologic changes in anastomotic sites under light microscope. The histologic changes we were concerned about were followings- thrombus formation, intimal edema, infiltration of inflammatory cells in media and adventitia, proliferation of endothelial cells and subintimal hyperplasia. Results : 1. All of the anastomosed arteries were patent when they were exposed for examination. 2. Thrombus formation and intimal edema were most severe in Vicryl group, followed by Ethilon, Prolene group in order. 3. The inflammatory cells infiltrated to the media and the adventitia most severely in Ethilon group, followed by Vicryl, Prolene group in order. 4. There was little difference in proliferation of endothelial cells in each group. 5. Subintimal hyperplasia was greater in Vicryl group than the others, but there was no significant difference between the Prolene and Ethilon groups. Conclusions : On the basis of these observations, we could conclude that Prolene may be the better suture material for microvascular anastomoses regarding the tissue responses than Ethilon and Vicryl.

• Archives of Plastic Surgery
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• 제46권4호
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• pp.344-349
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• 2019

Background Lymphaticovenous anastomosis is an important surgical treatment for lymphedema, with lymphaticovenous side-to-end anastomosis (LVSEA) and lymphaticovenous end-to-end anastomosis being the most frequently performed procedures. However, LVSEA can cause lymphatic flow obstruction because of regurgitation and tension in the anastomosis. In this study, we introduce a novel and simple procedure to overcome this problem. Methods Thirty-five female patients with lower extremity lymphedema who underwent lymphaticovenous anastomosis at our hospital were included in this study. Eighty-five LVSEA procedures were performed, of which 12 resulted in insufficient venous blood flow. For these 12 anastomoses, the proximal lymphatic vessel underwent clipping after the anastomotic procedure and the venous inflow was monitored. Subsequently, the proximal ligation after side-to-end anastomosis recovery (PLASTER) technique, which involves ligating the proximal side of the lymphatic vessel, was applied. A postoperative evaluation was performed using indocyanine green 6 months after surgery. Results Despite the clipping procedure, three of the 12 anastomoses still showed poor venous inflow. Therefore, it was not possible to apply the PLASTER technique in those cases. Among the nine remaining anastomoses in which the PLASTER technique was applied, three (33%) were patent. Conclusions Our findings show that achieving patent anastomosis is challenging when postoperative venous inflow is poor. We achieved good results by performing proximal ligation after LVSEA. Thus, the PLASTER technique is a particularly useful recovery technique when LVSEA does not result in good run-off.

• Archives of Plastic Surgery
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• 제46권3호
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• pp.214-220
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• 2019

Background Microvascular anastomosis patency is adversely affected by local and systemic factors. Impaired intimal recovery and endothelial mechanisms promoting thrombus formation at the anastomotic site are common etiological factors of reduced anastomosis patency. Epigallocatechin gallate (EGCG) is a catechin derivative belonging to the flavonoid subgroup and is present in green tea (Camellia sinensis). This study investigated the effects of EGCG on the structure of vessel tips used in microvascular anastomoses and evaluated its effects on thrombus formation at an anastomotic site. Methods Thirty-six adult male Wistar albino rats were used in the study. The right femoral artery was cut and reanastomosed. The rats were divided into two groups (18 per group) and were systemically administered either EGCG or saline. Each group were then subdivided into three groups, each with six rats. Axial histological sections were taken from segments 1 cm proximal and 1 cm distal to the microvascular anastomosis site on days 5, 10, and 14. Results Thrombus formation was significantly different between the EGCG and control groups on day 5 (P=0.015) but not on days 10 or 14. The mean luminal diameter was significantly greater in the EGCG group on days 5 (P=0.002), 10 (P=0.026), and 14 (P=0.002). Intimal thickening was significantly higher on days 5 (P=0.041) and 10 (P=0.02). Conclusions EGCG showed vasodilatory effects and led to reduced early thrombus formation after microvascular repair. Similar studies on venous anastomoses and random or axial pedunculated skin flaps would also contribute valuable findings relevant to this topic.