• Archives of Craniofacial Surgery
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• v.19 no.3
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• pp.200-204
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• 2018

Fibrous dysplasia (FD) is a rare, benign bone disease with abnormal bone maturation and fibroblastic proliferation. Optimal treatment of zone 1 craniofacial FD is radical resection and reconstruction. To achieve of structural, aesthetic, and functional goals, we use three-dimensionally designed calvarial bone graft for reconstruction of zygomatic defect after radical resection of FD. The authors used a rapid-prototyping model for simulation surgery for radical resection and immediate reconstruction. Donor site was selected from parietal bone reflect shape, contour, and size of defect. Then radical resection of lesion and immediate reconstruction was performed as planned. Outcomes were assessed using clinical photographs and computed tomography scans. Successful reconstruction after radical resection was achieved by three-dimensional calvarial bone graft without complications. After a 12-month follow-up, sufficient bone thickness and symmetric soft tissue contour was well-maintained. By considering three-dimensional configuration of zygomaticomaxillary complex, the authors achieved satisfactory structural, aesthetic and functional outcomes without complications.

• Annals of Surgical Treatment and Research
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• v.95 no.5
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• pp.258-266
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• 2018

Purpose: This study analyzes the impact of laparoscopic liver resection on intra-abdominal adhesion. Methods: Patients who underwent salvage liver transplantation after liver resection for hepatocellular carcinoma from January 2012 to October 2017 at our institution were included. Information about the severity of intra-abdominal adhesions was collected from a prospectively maintained database. Intra-abdominal adhesions were graded after the agreement of 2 surgeons who participated in the salvage liver transplantation based on predetermined criteria. Adhesion severity and demographic, operative, and postoperative data were compared between the laparoscopic group and the open group. Multivariate logistic regression was performed to consider potential factors related to severe adhesion during salvage transplantation. Results: Sixty-two patients who underwent salvage liver transplantation after liver resection were included in this study. Among them, 52 patients underwent open surgery, and 10 patients underwent laparoscopy. Adhesion was significantly more severe in the open group than in the laparoscopy group (P = 0.029). A multivariate logistic regression model including potential factors related to severe adhesion showed that laparoscopy (odds ratio, 0.168; 95% confidence interval, 0.029-0.970; P = 0.048) was the only significant factor. Conclusion: Laparoscopic liver resection for hepatocellular carcinoma can minimize intra-abdominal adhesion during salvage liver transplantation.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.117-122
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• 2012

Aim: To elucidate the effects of hyperthermic $CO_2$ pneumoperitoneum on human gastric AGS cells. Methods: Based on a newly devised in vitro study model, we evaluated the anti-cancer effects of HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) on human gastric cancer cells, and also the corresponding mechanisms. Results: HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) severely inhibited cell proliferation as assessed by Cell Counting Kit-8 assay, while inducing apoptosis in a temperature- and time-dependent manner demonstrated by annexin-V/PI flow cytometry and morphological analysis (Hoechst/PI fluorescence). In addition, it was found that HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) promoted the up-regulation of Bax by western blotting. Significantly, it could also suppress gastric cancer cell invasion and metastasis by in vitro invasion and motility assay. Conclusion: In conclusion, HT-$CO_2$ had an efficacious cytotoxic effect on gastric cancer cells through Bax-induced mitochondrial apoptotic signaling. Our studies indicate that it may serve as a potential therapy for peritoneal carcinomatosis of gastric cancer. Further investigations in vivo using animal models are now urgently needed.

• Health Policy and Management
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• v.25 no.2
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• pp.67-70
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• 2015

To establish an appropriate policy for robotic surgery in Korea, the National Evidence-based Collaborating Agency (NECA) and the Korean Society of Health Policy and Administration held a round-table conference (RTC) to gather opinions through a comprehensive discussion of scientific information in gastric cancer. The NECA RTC is a public discussion forum wherein experts from diverse fields and members of the lay public conduct in-depth discussions on a selected social issue in the health and medical field. For this study, representatives from the medical field, patient groups, industry, the press, and policy makers participated in a discussion focused on the medical and scientific evidence for the use of robotic surgery in gastric cancer. According to the RTC results, robotic surgery showed more favorable results in safety and efficacy than open surgery and it is similar to laparoscopy. When the cost-effectiveness of robotic surgery and laparoscopy is compared, robotic surgery costs are higher but there was no difference between the two of them in terms of effectiveness (pain, quality of life, complications, etc.). In order to resolve the high cost issue of the robotic surgery, a proper policy should be implemented to facilitate the development of a cost-effective model of the robotic surgery equipment. The higher cost of robotic surgery require more evidence of its safety and efficacy as well as the cost-effectiveness issues of this method. Discussions on the national insurance coverage of robotic surgery seems to be necessary in the near future.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.2
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• pp.113-122
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• 2007

Purpose: Platelet-rich plasma (PRP) is known to accelerate and/or enhance hard and soft tissue healing and regeneration. As such, PRP has been used in various clinical fields of surgery. Recently there have been several attempts to use PRP in the field of tissue engineering. However, some controversies still exist on exact mechanism and benefits of PRP. Therefore various animal experiments are necessary to reveal the effect of the PRP. However, even if animal experiment is performed, the efficacy of the experiment could not be validated due to absence of an animal PRP model. The purpose of this study is to establish rat PRP model by comparing several PRP fabricating methods, and to assay growth factor concentration in the PRP. Materials and methods: Rat blood samples were collected from nine SD rat (body weight: 600-800g). PRP was prepared using three different PRP fabricating methods according to previously reported literatures. (Method 1: 800 rpm, 15 minute, single centrifuge; Method 2: 1000 rpm, 10 minute, double centrifuge; Method 3: 3000 rpm, 4min and 2500 rpm, 8 min, double centrifuge). Platelet counts were evaluated in an automated machine before and after PRP fabrications. In terms of growth factor assay, prepared PRP were activated with 100 unit thrombin and 10% calcium chloride. Growth factor (PDGF-BB, VEGF) concentrations on incubation time were determined by sandwich-ELISA technique. Results: An average of 3ml (via infraorbital venous plexus) to 15ml (via celiac axis) the rat blood could be collected. By using Method 3 (3000 rpm, 4 min and 2500 rpm, 8 min, double centrifugation), around 1.5ml of PRP could be prepared. This method allowed us to concentrate platelet 3.77-fold on average. PDGF-BB concentration (mean, 1942.10 pg/ml after 1 hour incubation) and VEGF concentration (mean, 952.71 pg/ml after 1 hour incubation) in activated PRP were higher than those in untreated blood. Also PDGF-BB showed constant concentration during 4-hour incubation, while VEGF concentration was decreased after 1 hour. Conclusion: Total 11,000 g minute separation and condensation double centrifuge method can produce efficient platelet-rich plasma. Platelet-rich plasma activated with thrombin has showed higher concentrations of growth factors such as PDGF-BB and VEGF, compared to the control group. Platelet-rich plasma model in a rat model was confirmed in this study.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.231-239
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• 1988

Currently numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operation. During cardiac ischemia after crystalloid cardioplegia[4C GIK solution], topical cold saline[Group I, a=9], topical ice slush[Group II, n=9] and topical ice chip[Group III, a=10] have been compared for myocardial surface cooling in the isolated rat heart model of cardiopulmonary bypass. During postischemic period, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure and heart rate], biochemical enzymatic activities and cellular injuries with electron microscope were evaluated in this isolated rat heart perfusion model. Postischemic aortic flow, cardiac output and peak aortic pressure in Group I and Group II recovered better than Group III.[p< 0.05] Postischemic creatine kinase and lactate dehydrogenase leakages in Group II and Group III increased more than Group l and postischemic mitochondrial swelling in Group III was more severe than Group I, and Group II.[p< 0.05] These results suggest that topical cold saline was the better method than topical ice slush or topical ice chip as a myocardial preservation modality in the isolated rat heart model of cardiopulmonary bypass.

• Journal of International Society for Simulation Surgery
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• v.1 no.2
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• pp.83-86
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• 2014

Purpose This paper was purposed to suggest the method to produce the supportive helmet (head correction) for the infants who are suffering from plagiocephaly and to evaluate the level of transformation through 3D model. Method Either of CT or X-ray restored images has been used in making the supportive helmet (Head correction) in general, but these methods of measuring have problems in cost and safety. 3D surface measurement technology was suggested to solve such matters. Results It was to design the transformed model of the head within 0.7cm in average by scanning the surface of head and performing 3D restoration with marching cube and the changing rate of the head was compared in numerical data with 3D model. Conclusion The suggested methods displayed the better performance than the conventional method in respect of the speed and cost.

• Journal of the Korean Burn Society
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• v.24 no.1
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• pp.1-6
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• 2021

Purpose: The purpose of this study was to evaluate the accuracy of four prediction models in adult burn patients. Methods: This retrospective study was conducted on 696 adult burn patients who were treated at burn intensive care unit (BICU) of Hallym University Hangang Sacred Heart Hospital from January 2017 to December 2019. The models are ABSI, APACHE IV, rBaux and Hangang score. Results: The discrimination of each prediction model was analyzed as AUC of ROC curve. AUC value was the highest with Hangang score of 0.931 (0.908~0.954), followed by rBaux 0.896 (0.867~0.924), ABSI 0.883 (0.853~0.913) and APACHE IV 0.851 (0.818~0.884). Conclusion: The results of evaluating the accuracy of the four models, Hangang score showed the highest prediction. But it is necessary to apply the appropriate prediction model according to characteristics of the burn center.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.375-384
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• 2011

Purpose: The advent of microsurgical technique and instruments, particularly in the field of perforator flap and supermicrosurgery, which have expanded the scope of microsurgery. However, supermicroanastomosis without any compression, tension, or distortions must be achieved to reach successful outcomes. Small-caliber vessels, such as those with an internal diameter less than 0.2 mm, are susceptible to inadvertent twisting of the anastomosis. In this study, using the superficial inferior epigastric artery (SIEA)-based flap model in Sprague-Dawley (SD) rats, we evaluated the acceptable limits of twisting effects on supermicroanastomotic sites. Methods: A total of 20 supermicroanastomoses were performed using the SIEA-based flap model in 10 male SD rats, 10-weeks-of-age, weighing 300~350 g. Rats were divided into five groups of two with four flaps as follows: 1) sham, 2) control group with end to end SIEA arterial supermicroanastomosis, 3) experimental I (EA1) with $90^{\circ}$ twisting, 4) experimental II (EA2) with $180^{\circ}$ twisting, and 5) experimental III (EA3) with $270^{\circ}$ twisting of the supermicroanastomosis. Each SIEA was anastomosed using six 11-0 $Ethilon^{(R)}$ (Ethicon Inc. Co., NJ, USA) stitches except in the sham group where the SIEA was only clamped with Supermicro vascular $clamps^{(R)}$ (S&T, Neuhausen, Switzerland) for 20 minutes. Results: The anastomosed arterial patency showed no remarkable changes according to doppler waveforms measured with a Smardop 45 Doppler System (Hadeco Inc., Kawasaki, Japan). The pulsatility index (PI) was increased at postoperative day 10 in the EA2 and EA3 groups, and the resistance index (RI) showed no statistically significant difference between preoperative and postoperative values at 10 days. Histologic specimens from the EA3 group showed increased tunica media necrosis, convolution of the internal elastic lamina, densely packed platelets, fibrin, and erythrocytes. Flap viability and anastomosed vessel patency were not significantly affected by the degree of arterial twisting in this study, other than in the EA3 group where minor effects on arterial patency of the microanastomoses were encountered. Conclusion: It appears that minor twisting on small caliber arteries, used in supermicroanastomoses, can be tolerated. However, twisting should be avoided as much as possible, and more than $180^{\circ}$ twisting must be prevented in clinical practice.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.497-503
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• 2010

Purpose: The purpose of this study is to induce artificial arthritis on rabbit TMJ by injecting collagenase. Materials and Methods: An experimental animal model of arthritis induced by surgical method or intraarticular injection of chemical agent like LDH, papain, ketorolac. Surgical method is complex and needs a long time in inducing arthritis. Intra-articular injection of chemical agent like LDH, papain, ketorolac is simple. But chemical agent like LDH, papain, ketololac needs multiple injections to induce arthritis and mechanism inducing arthritis was known. Collagenase destroys helical domain of type II collagen in extracellular matrix produced by chondrocyte and then induces arthritis. We injected collagenase (0.5, 1.0, 2.0 mg) into the temporomandibular joint of rabbit. In the control group saline was intra-articularly injected. The condylar cartilage, disk and synovia were histologically examined at 1, 2, 4, 6 weeks after the initiation of collagenase injections. Results: Four weeks after injection of 2.0 mg collagenase, we could see histologic change like arthritis. In other groups, we couldn't see arthritis-like change. Conclusion: In our study, we produce arthritis on temporomandibular joint of rabbit by using injection of collagenase in temporomandibular joint of rabbit. And this experimental osteoarthritis is a useful animal model.