• Korean Journal of Bronchoesophagology
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• v.2 no.2
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• pp.213-221
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• 1996

To evaluate the clinical effectiveness of expandable metallic stents, the stents were implanted under endoscopic guidance with local anesthesia or general anesthesia for maintenance of the constructed subglottic space of trachea. The nine patients with respiration difficulty were subjected for expandable stents. The stenosis of upper airway were due to the framework problem of subglottic trachea and tracheostoma after total laryngectomy. Stents were constructed of 0.4 m stainless steel win in a zigzag configuration of 8 bends. A single stent was 20 m in diameter when fully expanded and 20 mm long. The stents were placed accurately to the stenotic site and followed to the 5 month after stent placement. The stenotic area became narrowed with overgrowing of granuloma in all patients and the metallic stents were removed and the stenotic area reconstructed surgically. As conclusion, this technique for the treatment of the subglottic trachea showed simple and safe, but highly recurred due to overgrowing of granuloma. We suggest that the expandable metallic stent is not encouraging in this study.

• Korean Journal of Bronchoesophagology
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• v.10 no.2
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• pp.17-21
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• 2004

Background Insertion of tracheal stent in the treatment of benign tracheal & bronchial disease has increased since the introduction of expandable metallic stent. Material & Methods : Between Jan, 1995 and Feb. 2004, eight patients who had benign tracheo-bronchial disease underwent insertion of expandable metallic tracheal stent. We retrospectively analyzed stent insertion indications, complications, and following the result. Results : Surgical indications were post-intubation tracheal stenosis (1 case), tracheal stenosis following tracheal surgery (2 cases), tracheo-esophageal fistula (2 cases), broncho-pleural fistula(1 case), left main bronchus stenosis following bronchoplasty (1 case), and left main bronchus stenosis due to mediastinal repositioning (1 case). Expandable metallic tracheal stent was inserted in five patients to resolve dyspnea caused by airway obstruction, and to prevent recurrent pneumonia in three patients. The complication developed in 6 patients $75\%$; 3 cases of distal stenosis due to growth of granulation tissue, and one case each of tearing of posterior membrane, aggravation of tracheo-esophageal fistula, and airway partial obstruction due to stent migration. The stent was removed in 5 patients and tracheal surgery (tracheal resection and end to end anastomosis with primary repair of esophagus, pericardial patch tracheo-bronchoplasty, tracheal repair and omental wrapping) was performed in 3 patients. Conclusion Insertion of self expandable metallic stent in benign tracheo-bronchial disease is an effective means of relieving dyspnea for only a short period, and it did not increase the long term survival. Better means of treatment of benign tracheo-bronchial stenosis in necessary.

• Journal of Biomedical Engineering Research
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• v.24 no.1
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• pp.37-44
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• 2003

This experimental study is aimed at evaluating the hydrodynamic performance of newly designed self-expandable graft stents under steady flow condition. Two graft stents with different coating materials and a bare TiNi metallic stent for comparison test were used in the experiment. Pressure variation and velocity distribution at the upstream and downstream of the stents were measured at flow rates of 5, 10, and 15 l/min, respectively. Pressure loss due to insertion of the stent increased with increasing flow rate exponentially as expected. At a flow rate of 15 l/min, pressure loss of Polyure-thane(PU)-coated graft stent was 6 times higher than that of TiNi metallic stent, while the pressure loss of a porous Polytetrafluoroethylene(PTFE)-coated graft stent was comparable to a bare TiNi metallic stent. Velocity profiles of the porous PTFE-coated graft stent were similar to those of a bare TiNi metallic stent regardless of flow rate. Furthermore, the velocity profile of PU-coated graft stent revealed an asymmetrical and relatively low central velocity at a higher flow rate than 10 1/min, expecially, where the effects resulted in increases of wall shear stress and normal stress. The worse hydrodynamic behavior of PU-coated graft stent than the other two stents might be attributed to formation of folds due to poor flexibility of coated material when inserting the graft stent into the pipe with a more smaller size, which later gave rise non-symmetry of flow area, increase of surface roughness and jet flow via the crevice between the stent and cylinder wall.

• Journal of Chest Surgery
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• v.28 no.2
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• pp.201-205
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• 1995

Most of the patient with endobronchial tuberculosis have some degree of bronchial stenosis. however, a part of bronchial stenosis need aggressive treatment for the patency because of severe symptoms. The self-expendable metallic stents provide palliative treatment for narrowed airways where surgical resection is inadvisable. We experienced a successful left wedge pneumonectomy on a 29-year-old woman with obstruction of left main bronchus due to complication of the bronchial stent. She had inserted self-expendable metallic stents on left main bronchus of the tuberculous bronchial stenosis two times. There was no specific postoperative complication.

• Korean Journal of Radiology
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• v.21 no.6
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• pp.695-706
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• 2020

Objective: To investigate the technical and clinical efficacy of the percutaneous insertion of a biliary metallic stent, and to identify the factors associated with biliary stent dysfunction in patients with malignant duodenobiliary obstruction. Materials and Methods: The medical records of 70 patients (39 men and 31 women; mean age, 63 years; range, 38-90 years) who were treated for malignant duodenobiliary obstruction at our institution between April 2007 and December 2018, were retrospectively reviewed. Variables found significant by univariate log-rank analysis (p < 0.2) were considered as suitable candidates for a multiple Cox's proportional hazard model. Results: The biliary stents were successfully placed in all 70 study patients. Biliary stent insertion with subsequent duodenal stent insertion was performed in 33 patients and duodenal stent insertion with subsequent biliary stent insertion was performed in the other 37 study subjects. The median patient survival and stent patency time were 107 days (95% confidence interval [CI], 78-135 days) and 270 days (95% CI, 95-444 days), respectively. Biliary stent dysfunction was observed in 24 (34.3%) cases. Multiple Cox's proportional hazard analysis revealed that the location of the distal biliary stent was the only independent factor affecting biliary stent patency (hazard ratio, 3.771; 95% CI, 1.157-12.283). The median biliary stent patency was significantly longer in patients in whom the distal end of the biliary stent was beyond the distal end of the duodenal stent (median, 327 days; 95% CI, 249-450 days), rather than within the duodenal stent (median, 170 days; 95% CI, 115-225 days). Conclusion: The percutaneous insertion of the biliary metallic stent appears to be a technically feasible, safe, and effective method of treating malignant duodenobiliary obstruction. In addition, a biliary stent system with a distal end located beyond the distal end of the duodenal stent will contribute towards longer stent patency in these patients.

• Tuberculosis and Respiratory Diseases
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• v.41 no.1
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• pp.47-50
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• 1994

To maintain an adequate airway in a patient with tracheobronchial narrowing coming from various causes, prosthetic tracheobronchial stents provide palliative treatment for narrowed airways where surgical resection is inadvisable. After insertion, previous reported complications were granuloma formation, dysphagia, suction catheter entrapment and fatal massive hemoptysis. We report, a case of complication associated with expandible metallic stent with endobronchial stenosis due to tuberculosis.

• Clinical Endoscopy
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• v.57 no.4
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• pp.424-433
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• 2024

Colonic stent placement is a commonly used bridging strategy for surgery in patients with obstructive colorectal cancer. The procedure involves the placement of a self-expandable metallic stent (SEMS) across the obstructive lesion to restore intestinal patency and alleviate the symptoms of obstruction. By allowing patients to receive surgery in a planned and staged manner with time for preoperative optimization and bowel preparation, stent placement may reduce the need for emergency surgery, which is associated with higher complication rates and poorer outcomes. This review focuses on the role of colon stenting as a bridge to surgery in the management of obstructive colorectal cancer. SEMS as a bridge to surgery for left-sided colon cancer has been demonstrated to be particularly useful; however, further research is needed for its application in cases of right-sided colon cancer. Colon stent placement also has limitations and potential complications including stent migration, re-obstruction, and perforation. However, the timing of curative surgery after SEMS placement remains inconclusive. Considering the literature to date, performing surgery at an interval of approximately 2 weeks is considered appropriate. Therefore, colonic stent placement may be an effective strategy as a bridge to surgery in patients with obstructive colorectal cancer.

• The Korean Journal of Gastroenterology
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• v.72 no.5
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• pp.262-266
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• 2018

Surgery has been the standard treatment for perforated duodenal ulcers, with mostly good results. However, the resolution of postoperative leakage after primary repair of perforated duodenal ulcer remains challenging. There are several choices for re-operation required in persistent leakage from perforated duodenal ulcers. However, many of these choices are complicated surgical procedures requiring prolonged general anesthesia that may increase the chances of morbidity and mortality. Several recent reports have demonstrated postoperative leakage after primary repair of a perforated duodenal ulcer treated with endoscopic insertion using a covered self-expandable metallic stent, with good clinical results. We report a case with postoperative leakage after primary repair of a perforated duodenal ulcer treated using a covered self-expandable metallic stent.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.497-502
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• 2018

The coronary artery disease (CAD) is rapidly increasing such as angina pectoris and atherosclerosis. The CAD is induce by cholesterol and calcium like plaque absortion to artery wall. The percutaneouss coronary intervention is non-invasive treatment that narrowed-artery is expand by using balloon catheter and bare metallic stent. The metallic stents have been effective in reducing the dead by coronary artery disease, but the permanent presence of the metallic stent has been associated with persistent inflammation, and incidence of late thrombosis. Therefore, development bioresorbable vascular scaffold (BRS) is rapidly increasing for treatment of long-term complications and arterial restenosis by permanentmetal prosthesis such as stent. The review discusses the BRS trend for successfully development.

• Clinical Endoscopy
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• v.55 no.3
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• pp.434-442
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• 2022

Background/Aims: Covered self-expandable metallic stents (CMSs) are widely used for malignant distal biliary obstructions (MDBOs) caused by pancreatic carcinoma. This study compared the efficacy and safety of the laser-cut-type and braided-type CMSs. Methods: To palliate MDBOs caused by pancreatic carcinoma, the laser-cut-type CMSs was used from April 2014 to March 2017, and the braided-type CMSs was used from April 2017 to March 2019. The tested self-expandable metallic stents were equipped with different anti-migration systems. Results: In total, 47 patients received CMSs for MDBOs (24 laser-cut type, 23 braided-type). The time to recurrent biliary obstruction (TRBO) was significantly longer in the braided-type CMSs (p=0.0008), and the median time to stent dysfunction or patient death was 141 and 265 days in the laser-cut-type CMSs and braided-type CMSs, respectively (p=0.0023). Stent migration was the major cause of stent dysfunction in both groups, which occurred in 37.5% of the laser-cut-type CMSs and 13.0% of the braided-type CMSs. There were no differences in the survival duration between the groups. Conclusions: The TRBO was significantly longer for the braided-type CMSs with an anti-migration system than for the laser-cut-type. Stent migration tended to be less frequent with the braided-type CMSs than with the laser-cut-type CMSs.