• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.495-497
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• 2009

Carotid angioplasty and stenting (CAS) for carotid stenosis has been increasingly used as an alternative treatment in patients not eligible for surgery. Even though CAS can be performed relatively simply in many cases, various complications can occur. We report four cases of CAS using the Carotid Wallstent, which were complicated by delayed shortening of the stent, resulting in restenosis after successful CAS.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.2
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• pp.130-136
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• 1995

Vestibuloplasty are following categories : Mucosal advancement(submucous), secondary epithlization(reepithelization) and grafting vestibuloplasty. Although certain procedures are indicated for alveolar bone loss and sulcus shortening, relapse can occur. Every efforts to minimize or compensate for it is controversy. O'Steen(1970) reported the mucous graft methods that none of vestibular shrinkage and graft contracture. 15patients in mucous graft vestibuloplasty with fibrin adhesive system(Beriplast) were taken in cases of alveolar bone resorption and mucosal shortening due to traumatized alveolar bone defects, senile atrophic alveolar bone, postoperative cyst or tumor resection, edentulous alveolar bone loss, and others. A technique in the use of small piece of palatal mucosa$(1{\times}20mm)$ from the lateral aspect of the palate with adhesive system provided to secure the skin grafts, avoid stent fixation, postoperative patient's comfort and less time-consuming than the standard technique, especially excellent bleeding control.

• Progress in Medical Physics
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• v.20 no.3
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• pp.119-124
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• 2009

Stents are frequently used throughout the human body. They keep pathways open in vascular or nonvascular duct for a long time. Therefore its stability is very important factor. In recent years, aconsiderable amount of research has been carried out in order to estimate mechanical properties of the stent such as expansion pressure behavior, radial recoil and longitudinal recoil using FEM (Finite element analyses). However, published works on simulation of stent fatigue behavior using FEM are relatively rare. In this paper, a nonlinear finite-element methodwas employed to analyses the compression of a stent using external pressure and fatigue behavior. Finite element analyses for the stent system were performed using NASTRAN FX. In conclusion this paper shows how the stent is behaved in the body, and its fatigue behavior.

• Polymer(Korea)
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• v.36 no.2
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• pp.163-168
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• 2012

Recently, along with technology development of endoscopic equipment, the stent technology has been developed for the convenience of operation, shortening of recovery times, and reduction of patient's pain. In this study, paclitaxel-eluting metal stents for treatment of biliary benign stenosis were developed through an electrospray-coating method. Polyether-based polyurethane (PELLETHANE 2363-80AE$^{(R)}$)) and paclitaxel were coated onto the surface of a metallic stent and Pluronic F127 was used as an additive. As a result, physicochemical characterization of paclitaxel via SEM, FTIR, contact angle and XRD techniques revealed the information of solid state of paclitaxel-loaded PU film. The in vitro release profile showed a slower release rate with a higher content of paclitaxel.

• Progress in Medical Physics
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• v.21 no.2
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• pp.201-208
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• 2010

Recently, along with technology development of endoscopic equipment, a stent has been developed for the convenience of operation, shortening of recovery times, and reduction of patient's pain. To this end, optimal factors are simulated for the stent structure and mechanical reaction and verified using finite element analysis. In order to compare to present commercialized product such as Zilver (Cook, Bloomington, Indiana, USA) and S.M.A.R.T (Cordis, Bridgewater Towsnhip, New Jersey, USA), mechanical impact factors were determined through Taguchi factor analysis, and flexibility and expandability of all the products including ours were tested using finite element analysis. Also, important factors were sought that fulfill the optimal condition using central composition method of response surface analysis, and optimal design were carried out based on the important factors. From the centra composition method of Response surface analysis, it is found that importat factors for flexibility is stent thickness (T) and unit area (W) and those for expandability is stent thickness (T). In results, important factors for optimum condition are 0.17 mm for stent thickness (T) and $0.09\;mm^2$ for unit area (W). Determined and verified by finite element analysis in out research institute, a stent was manufactured and tested with the results of better flexibility and expandability in optimal condition compared to other products. Recently, As Finite element analysis stent mechanical property assessment for research much proceed. But time and reduce expenses research rarely stent of optimum coditions. In this research, Important factor as mechanical impact factor stent Taguchi factor analysis arrangement to find flexibility with expansibility as Finite element analysis. Also, Using to Center composition method of Response surface method appropriate optimized condition searching for important factor, these considering had design optimized. Production stent time and reduce expenses was able to do the more coincide with optimum conditions. These kind of things as application plan industry of stent development period of time and reduce expenses etc. be of help to many economic development.

• Korean Journal of Bronchoesophagology
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• v.1 no.1
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• pp.129-135
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• 1995

The superiorly based flap tracheostomy(SBFT) has been advocated as an new technique of tracheostomy to manage a wide variety of causes of upper airway obstruction. This technique has particular applicability in patients who require long term tracheostomy such as in bilateral vocal cord paralysis and severe obstructive sleep apnea. SBFT has numerous advantages such as shortening of the gap between the skin and trachea : construction of a self-sustaining tract ; circumferential mucocutaneous junction to reduce infection, granulation tissue, bleeding, and stenosis of the tract : avoidance of the laryngotracheal damage : easy placement of a tracheostomal stent to promote speech, coughing and swallowing. Most of all, this technique can reduces the suprastomal buckling by the support of the superiorly based tracheal flap, and thus prevents the stenosis of suprastomal airway. The disadvantage of SBFT is more time-consuming procedure than the conventional tracheostomy, A retrospective analysis of 8 patients undergoing SBFT between June, 1994 and March, 1995 in Dankook University Hospital was performed to present the surgical technique and com-plication rates. The average duration of follow up was 11 months. The complications were consisted of a wound infection and a sternal granulation. The other complications including wound dehiscence, tracheitis, pneumonia, tracheal granulation, sternal narrowing and subglottic stenosis were not experienced.

• Journal of Korean Neurosurgical Society
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• v.63 no.1
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• pp.14-25
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• 2020

Proximal flow control achieved with a balloon guide catheter (BGC) during endovascular treatment of acute ischemic stroke is reviewed in this article. In clinical practice, BGCs offer a multi-faceted approach for clot retrieval by creating proximal flow arrest, reducing embolic burden, and shortening procedure time. Evaluation of frontline thrombectomy procedures with BGCs revealed advantages of combined use over the conventional guide catheter (CGC), notably in the significant reduction of distal emboli to both the affected and previously unaffected territories. Recently, new measures of early and complete reperfusion at first thrombectomy pass have been identified as independent predictors of improved outcomes, which were consistently demonstrated with use of BGC as a safe and effective option to minimize number of passes during intervention. Prior randomized controlled trials reported the positive correlation between BGC-treated patients and a lower risk of mortality as well as shortened procedure time. While BGC use is more common in stent retriever-mediated mechanical thrombectomy, preliminary data has shown the potential benefit of device application during contact aspiration thrombectomy to achieve successful recanalization. However, the question of which major endovascular strategy reigns superior as a frontline remains to be answered. Along with clinical case assessments, BGC performance during in-vitro simulation was analyzed to further understand mechanisms for optimization of thrombectomy technique.