• 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.

• Journal of Korean Neurosurgical Society
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• 제56권2호
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• pp.168-170
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• 2014

Dural arteriovenous fistula (AVF) is very rare, acquired lesion that may present with intracranial hemorrhage or neurological deficits. The etiology is not completely understood but dural AVF often has been associated with thrombosis of the involved dural sinuses. To our knowledge, this is the first well documented intracranial hemorrhage case caused by dural AVF following microvascular decompression for hemifacial spasm. A 49-year-old male patient had left microvascular decompression of anterior inferior cerebellar artery via retrosigmoid suboccipital craniotomy. The patient was in good condition without any residual spasm or surgery-related complications. However, after 10 months, he suffered sudden onset of amnesia and dysarthria. Computed tomography and magnetic resonance imaging revealed the presence of dural AVF around the left transverse-sigmoid sinus. The dural AVF was treated with Onyx$^{(R)}$ (ev3) embolization. At the one-year follow up visit, there were no evidence of recurrence and morbidity related to dural AVF and its treatment. This case confirms that the acquired etiology of dural AVF may be associated with retrosigmoid suboccipital craniotomy for hemifacial spasm, even though it is an extremely consequence of this procedure.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.29.1-29.7
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• 2020

Background: Microvascular reconstruction is the treatment of choice after oral cancer ablation surgery. There are few published studies of free flap survival among Korean populations. This study aimed to determine the survival rate after 121 consecutive cases of maxillofacial microvascular reconstruction and to analyze the complications associated with microsurgery. Methods: This study included consecutive patients who underwent microsurgical reconstruction with free flaps, from January 2006 through September 2019, performed by a single surgeon at the oral and maxillofacial surgery department of a tertiary medical center. A total of 121 cases were reviewed retrospectively. The flap survival rate, flap type, radiotherapy history, complications, and treatment results were analyzed. Results: Four different flap types were used for microvascular reconstruction: radial forearm (n = 65), fibula (n = 34), latissimus dorsi (n = 21), and serratus anterior muscle with rib bone free flap (n = 1). Total necrosis of the flap was found in four cases (two latissimus dorsi flaps and two fibular flaps). The free flap survival rate was 97.5%. Nineteen patients received radiotherapy before surgery, and none of them experienced flap failure. The mean operation time was 334 ± 83.1 min, and the mean ischemic time was 48.9 ± 12.7 min. Conclusions: The success rate was reliable and comparable with previous studies. The success rate was not affected by radiation therapy. Free flaps can be safely used even after radiation treatment.

• Archives of Reconstructive Microsurgery
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• 제8권1호
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• pp.22-27
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• 1999

While the conventional end-to-end anastomotic technique is accepted as 'the golden standard' for microvascular anastomosis, it is time-consuming and tedious. In an effort to offer faster and safer ways of performing microvascular anastomoses, numerous anastomotic techniques have been proposed, but further refinements in microvascular techniques are still necessary. A 'continuous suture with interrupted knot' technique was devised for faster and safer anastomosis. It has been successfully used in microanastomoses of both artery and vein for free tissue transfer. It is a combination of the interrupted suturing technique and the continuous suturing technique. First, a continuous suture is made with the size of loop decreasing in order, and then the sutures are tied individually from the first loop to the last one as in the conventional interrupted suturing technique. It was applied clinically to fourteen patients over the past ten months and found to be a highly efficient technique that satisfied our needs. This 'continuous suture with interrupted knot' technique has several advantages over other techniques : The operative time is reduced comparing conventional interrupted suture technique. By delaying the tie and with the vessel walls kept separated, the risk of through-stitch can be reduced. Tying all the sutures at one time not only speed up the procedures, but also reduced the surgeon's fatigue. In addition, it has no problem of anastomotic stenosis which is a disadvantage of continuous suture technique. This technique proved to be faster and safer, and has patency equal to that of the conventional end-to-end anastomosis. It is of great help to the surgeon in reducing operative time, especially in clinical situations when many anastomoses are required, or lengthy grafting procedures are undertaken.

• Archives of Plastic Surgery
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• 제42권6호
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• pp.741-745
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• 2015

Background Microvascular complications after free-flap breast reconstructions are potentially devastating problems that can increase patient morbidity and lead to flap loss. To date, no comprehensive study has examined the rates of salvage and the methods of microvascular revision in breast reconstruction. We reviewed the treatment of microvascular complications of free-flap breast reconstruction procedures over a seven-year period. Methods A retrospective review of all patients who underwent microvascular breast reconstruction at our institution between April 2006 and December 2013 was conducted. Based on their surgical records, all patients who required emergency re-exploration were identified, the rate of flap salvage was determined, the factors associated with flap salvage were evaluated, and the causes and methods of revision were reviewed. Results During the review period, 605 breast reconstruction procedures with a free lower abdominal flap were performed. Seventeen of these flaps were compromised by microvascular complications, and three flaps were lost. The overall salvage rate was 82.35%. No significant differences between the salvaged group and the failed group were observed with regard to age, BMI, axillary dissection, number of anastomotic arteries and veins, recipient vessel types, or use of the superficial inferior epigastric vein in the revision operation. Successful salvage of the flap was associated with a shorter time period between recognizing the signs of flap compromise and the take-back operation. Conclusions The salvage rate of compromised lower abdominal flaps was high enough to warrant attempting re-exploration. Immediate intervention after the onset of flap compromise signs is as important as vigilant postoperative monitoring.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권4호
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• pp.312-320
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• 2011

A reconstruction following a resection of malignant oral cavity tumors is one of the most difficult problems in recent oral oncology. For a better understanding of oral and maxillofacial reconstructive procedures, basic and advanced microvascular anastomosis techniques must be learned and memorized. The aim of this article was to clarify and define the microvascular anastomosis methods, such as primary closure after an arteriotomy, end to side anastomosis, end to end anastomosis, and side to side anastomosis with an artery and vein. This review article discusses the basic skills regarding microvascular anastomoses with brief schematic diagrams in the Korean language. This article is expected to be helpful, particularly to young doctors in the course of the Korean national board curriculum periods for oral and maxillofacial surgery.

• 동의생리병리학회지
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• 제20권6호
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• pp.1658-1663
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• 2006

Panax notoginseng (Buck) F.H chen. root (PNS) is used as a therapeutic agent to stop haemorrhages and a tonic to promote health in Korean and Chinses medicine. The pharmacokinetic profiles of the main PNS are still not accurately investigated. Our preliminary aim is to elucidate the pharmacokinetics features of the PNS in rats. Objective of this study is to determine whether PNS affects hepatic microvascular dysfunction elicited by gut ischemia and reperfusion (I/R), since gut I/R causes hepatic microvascular dysfunction, and to investigate the role of nitric oxide (NO). No has been found to be a modulator of the adhesive interactions between platelet and endothelial cells. Male Wistar rats were exposed to 30 min of gut ischemia followed by 60 min of reperfusion. Intravital microscopy was used to monitor the number of non-perfused sinusoids (NPS). In another set of experiments, PNS (1 g/kg pre day intragastrically) was administered to rats for 7 days. In some experiments, dexamethasone (ST) (2 mg/kg per day intravenously) was administered. In control rats, gut I/R elicited increases in the number of NPS, and plasma TNF-${\alpha}$ and ALT activities, and these changes were mitigated by the pretreatment with PNS. Pretreatment with an No synthase inhibitor diminished the protective effects of PNS on the increase in NPS and plasma TNF-${\alpha}$ levels, but not its effect on the increase in plasma ALT activities. Pretreatment with PNS increased plasma nitrite/nitrate levels. The responses caused by gut I/R were attenuated by the pretreatment with ST. Pretreatment with an NO synthase inhibitor did not affect the effect of ST. These results suggest that PNS attenuates the gut I/R-induced hepatic microvascular dysfunction and inflammatory responses such as TNF-${\alpha}$ production in the early phase via enhancement of NO production, and sequential hepatocellular damage via its anti-inflammatory effect like corticosteroid effect.

• 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.

• 대한의생명과학회지
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• 제12권2호
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• pp.127-130
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• 2006

It is important to coordinated interaction among neurons, astrocytes and endothelial cells to maintain the function of brain. To study their regulatory mechanisms in vitro system, the co-culture system among the isolated cells from brain may be needed. However, the method for purifying brain microvascular endothelial cells (BMEC) far culture have not established yet. In this study, the proper culture methods of mice cells using two different strains, CD1 and C57BL6, to obtain the pure and plentiful endothelial cells were described. The flatted-round forms of CD1 endothelial cells grew on the collagen-IV coating plates, while the purified cells from C57 mice preferred type collagen-I dishes for their growth. Both cells displayed anti-PECAM-1 (CD31) and von Willebrand Factor immune-reactivity. These results indicated that different coating materials not only improve attachment of isolated cells but also promoting growth of cells, suggesting that this method of purifying murine Brain microvascular endothelial cells (BMEC) provides a suitable model to investigate blood-brain-barrier (BBB) properties within neurovascular unit in vitro.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6639-6643
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• 2015

Background: Prostate cancer is a major concern of public health. Microvascular density (MVD) is one of the prognostic markers for various solid cancers. Matrix metalloproteinase 11 (MMP11) plays an important role in angiogenesis and changes in its expression level are known to be associated with tumor progression and clinical outcome. Aim: To investigate the relationship between MVD and MMP11 expression in prostatic adenocarcinoma tissues. Materials and Methods: The expression levels of MMP11 and MVD were analyzed immunohistochemically for 50 specimens of prostatic adenocarcinoma. Results: MMP11 was mainly expressed in stromal cells but rarely seen in epithelial cells. Mean MVD was $36/mm^2$, and it was correlated significantly only with bone metastases. MVD was also significantly correlated with MMP11 expression (r=0.29, p=0.044). Conclusions: MMP11 may alter the stromal microenvironment of prostate cancer to stimulate tumor angiogenesis.