• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.2
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• pp.80-85
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• 2014

Side jet thruster using nozzle closure separation device provides a solid rocket with a trajectory shift function. Side jet thruster consists of low combustion temperature propellant, neutral type propellant grain and nozzle closure separation device. If a trajectory shift is required, side jet thrust is generated on the rocket by separating some nozzle closures located in the opposite direction to thrust. After completing trajectory shift, the other nozzle closures located in the thrust direction are separated to cease side jet thrust. The operation process is verified through ground static test. The result in this study can be applied to changing rocket trajectory by controlling side jet thrust through nozzle closure separation.

• Journal of Chest Surgery
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• v.50 no.1
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• pp.47-49
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• 2017

Percutaneous closure of atrial septal defect (ASD) has become an increasingly common procedure. Serious complications of the procedure, such as cardiac migration, are rare, and usually occur <72 hours after device placement. In this report, we present the case of a patient who underwent successful surgical treatment for the migration of an ASD occluder device to the thoracic aorta 12 months after ASD closure.

• Journal of Chest Surgery
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• v.48 no.3
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• pp.202-205
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• 2015

Formation of an aneurysm in the sinus of Valsalva of the aortic root is usually due to an area of congenital weakness in its wall. This aneurysm may progressively dilate and rupture into any of the cardiac chambers or into the pericardial cavity. Though this is conventionally treated by surgery, interventional therapy using various closure devices is becoming more common. Embolization of these closure devices may occur. We report a case of embolization of such a device into the left pulmonary artery which during surgical retrieval, unmasked the hidden ventricular septal defect (VSD). Therefore one has to be cautious while making a diagnosis of rupture of the sinus of Valsalva of right coronary sinus without VSD.

• Journal of Chest Surgery
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• v.39 no.11 s.268
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• pp.864-867
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• 2006

Percutaneous suture closure device is known as relatively safe and convenient tool, which can decrease not only bed rest period of patient but also time consuming effort of manual compression of doctor after femoral artery puncture. However[C1], there are also some reports on complication of its use. We report a 62-year-old male patient who had femoral artery endarteritis[0] with pseudoaneurysm as a complication of percutaneous suture closure device after percutaneous coronary angiography[C2]. He was treated successfully by appropriate antibiotics and vessel reconstruction using autologous saphenous vein patch.

• Fire Science and Engineering
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• v.25 no.2
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• pp.132-137
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• 2011

A relationship between resisting moment and the structure of an automatic closure device is introduced for analyzing the effect of opening and closing condition on various fire door sizes in the pressurized room for smoke control system. The larger the size of fire door is, the more force is required for reaching to opening and closing conditions and there exists the design range of fire door in the pressurized room reflecting the closing time of fire door, rotative velocity, a relation between rotative angle and force and the efficiency of the automatic closure device.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.2
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• pp.147-162
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• 2022

Purpose: To design a prospective study on endovascular closure of congenital portosystemic shunts. The primary endpoint was to assess the safety of endovascular closure. The secondary endpoint was to evaluate the clinical, analytical and imaging outcomes of treatment. Methods: Fifteen patients (age range: 2 days to 21 years; 10 male) were referred to our center due to congenital portosystemic shunts. The following data were collected prior to treatment: age, sex, medical history, clinical and analytical data, urine trimethylaminuria, abdominal-US, and body-CT. The following data were collected at the time of intervention: anatomical and hemodynamic characteristics of the shunts, device used, and closure success. The following data were collected at various post-intervention time points: during hospital stay (to confirm shunt closure and detect complications) and at one year after (for clinical, analytical, and imaging purposes). Results: The treatment was successful in 12 participants, migration of the device was observed in two, while acute splanchnic thrombosis was observed in one. Off-label devices were used in attempting to close the side-to-side shunts, and success was achieved using Amplatzer™ Ductus-Occluder and Amplatzer™ Muscular-Vascular-Septal-Defect-Occluder. The main changes were: increased prothrombin activity (p=0.043); decreased AST, ALT, GGT, and bilirubin (p=0.007, p=0.056, p=0.036, p=0.013); thrombocytopenia resolution (p=0.131); expansion of portal veins (p=0.005); normalization of Doppler portal flow (100%); regression of liver nodules (p=0.001); ammonia normalization (p=0.003); and disappearance of trimethylaminuria (p=0.285). Conclusion: Endovascular closure is effective. Our results support the indication of endovascular closure for side-to-side shunts and for cases of congenital absence of portal vein.

• Clinical and Experimental Pediatrics
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• v.50 no.5
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• pp.469-475
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• 2007

Purpose : This study was performed to compare the safety, efficacy and clinical results of the Amplatzer septal occluder (ASO) for closure of secundum atrial septal defect (ASD) with surgery. Methods : One hundred fifteen patients diagnosed as isolated secundum ASD in Gil Medical Center, Gachon University of Medicine from January 2000 to July 2006 were included. Seventy patients underwent surgical repair of ostium secundum ASD. Forty-five consecutive patients were treated with percutaneous closure using ASO. We compared the mortality, morbidity, hospital stay, and efficacy between two groups. Results : Male to female ratio was 1:2.4. The mean age and the size of defects were not statistically different. No mortality occurred in either group. The success rate was 97.8% in the device group and 100% in the surgical group. The overall rate of complications was higher in the surgical group than in the device group (64.0 vs. 15.6%, P<0.05). Hospital stay was shorter in the device group than in the surgical group ($4.2{\pm}1.2$ vs. $12.4{\pm}4.7days$, P<0.0001). Residual shunt rates were more frequent in the device group (8.9%) than in the surgical group (4.3%) at discharge. All residual shunts disappeared at 3 months follow-up. Conclusion : Percutaneous closure of ASD using ASO is a safe and effective alternative to surgical repair. The indications of percutaneous ASD closure with ASO would be expanded by accumulation of experiences and evolutions of device.

• Journal of Chest Surgery
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• v.54 no.5
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• pp.383-388
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• 2021

Background: Achieving external access to and manual occlusion of the left atrial appendage (LAA) during minimally invasive mitral valve surgery (MIMVS) through a small right thoracotomy is difficult. Occlusion of the LAA using an epicardial closure device seems quite useful compared to other surgical techniques. Methods: Fourteen patients with atrial fibrillation underwent MIMVS with concomitant surgical occlusion of the LAA using double-layered endocardial closure stitches (n=6, endocardial suture group) or the AtriClip Pro closure device (n=8, AtriClip group) at our institution. The primary safety endpoint was any device-related adverse event, and the primary efficacy endpoint was successful complete occlusion of blood flow into the LAA as assessed by transthoracic echocardiography at hospital discharge. The primary efficacy endpoint for stroke reduction was the occurrence of ischemic or hemorrhagic neurologic events. Results: All patients underwent LAA occlusion as scheduled. The cardiopulmonary bypass and aortic cross-clamp times in the endocardial suture group and the AtriClip group were 202±39 and 128±41 minutes, and 213±53 and 136±44 minutes, respectively (p=0.68, p=0.73). No patients in either group experienced any device-related serious adverse events, incomplete LAA occlusion, early postoperative stroke, or neurologic complication. Conclusion: Epicardial LAA occlusion using the AtriClip Pro during MIMVS in patients with mitral valve disease and atrial fibrillation is a simple, safe, and effective adjunctive procedure.

• Clinical and Experimental Pediatrics
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• v.57 no.7
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• pp.297-303
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• 2014

Transcatheter closure of atrial septal defects has become a popular procedure. The availability of a preprocedural imaging study is crucial for a safe and successful closure. Both the anatomy and morphology of the defect should be precisely evaluated before the procedure. Three-dimensional (3D) echocardiography and cardiac computed tomography are helpful for understanding the morphology of a defect, which is important because different defect morphologies could variously impact the results. During the procedure, real-time 3D echocardiography can be used to guide an accurate closure. The safety and efficiency of transcatheter closures of atrial septal defects could be improved through the use of detailed imaging studies.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.121-126
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• 2011

Purpose: Vaccum-assisted closure (VAC) has rapidly evolved into a widely accepted treatment of contaminated wounds, envenomations, infiltrations, and wound complications. This results in a sealed, moist environment where tissue is given the opportunity to survive as edema is removed and perfusion is increased. Many plastic surgeons now place a VAC device directly over the fasciotomy site at the time of the initial procedure. Large amounts of the fluid are withdrawn, and fasciotomies can be closed primarily sooner. This study was designed to observe the effect of VAC in preventing complications in snake bitten hands. Methods: In our study of three cases of snake bite, three of them underwent the VAC treatment & fasciotomy of the wound in the hand. This cases, the posterior compartment of the hand was bitten for a few days, releasing incisions were made of the posterior hand and 125 mmHg of continuous vacuum was applied to fasciomy incision site and the biting wound. The dressings were changed three times per week. Results: Our study examining the effects of applied vacuum in preventing snake bite wounds showed that the incidence of tissue necrosis and compartment syndrome was significantly lower for vacuum-treated wounds than for conservative wounds. Serum myoglobin, CK-MB, and CPK levels measured after fasciotomy incision were significantly decreased. We obtained satisfactory results from early dorsal fasciotomy, drainage of the edema with the VAC system, and then primary closure. The postoperative course was uneventful. Conclusion: Envenomation is a term implying that sufficient venom has been introduced into the body to cause either local signs at the site of the bite and/or systemic signs. Use of the vacuum-assisted closure device in snake bite can result in a decreased rate of tissue necrosis, lymphatic fluid collection, hemolytic fluid collection, and edema. Early fasciotomy of the dorsal hand and VAC apply is the alternative treatment of the snake bite.