• Korean Journal of Bronchoesophagology
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• v.14 no.2
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• pp.10-16
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• 2008

Surgical resection and reanastomosis has been the treatment of choice in patients with tracheobronchial stenosis. Recent development of bronchoscopic intervention has been replacing the role of surgery in these patients. After summarizing the upto date data of bronchoscopic intervention, the proper management of tracheobronchial stenosis will be presented. Bronchoscopic intervention would be much effective when performed under rigid bron- choscopy, due to the stable patients' condition and endoscopic view. The usual method of intervention includes ballooning, Nd-YAG laser resection, bougienation, mechanical airway dilatation, stenting and photodynamic therapy. Silicone stents are very effective in patients with tracheobronchial stenosis to maintain airway patency. Bronchoscopic intervention provided immediate symptomatic relief and improved lung function in most of patients. After airway stabilization, stents were removed successfully in 2/3 of the patients at a 12-18 months post-insertion. Less than 5% of patients eventually needs surgical management. Acute complications, including excessive bleeding, pneumothorax, and pneumomediastinum develops in less than 5% of patients but managed without mortality. Stent-related late complications, such as, migration, granuloma formation, mucostasis, and restenosis are relatively high but usually controlled by follow-up bronchoscopy. In conclusion, bronchoscopic intervention, including silicone stenting could be a useful and safe method for treating tracheobronchial stenosis.

• Clinical Endoscopy
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• v.56 no.6
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• pp.726-734
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• 2023

Background/Aims: Endoscopic stenting for stricturing Crohn's disease (CD) is an emerging treatment that achieves more persistent dilatation of the stricture over time than endoscopic balloon dilatation (EBD). We aimed to explore the efficacy and safety of stenting for the treatment of CD strictures. Methods: A systematic electronic literature search was performed (PROSPERO; no. CRD42022308033). The primary outcomes were technical success, efficacy, complication rate, and the need for further interventions due to reobstruction. The outcomes of partially covered self-expanding metal stents (PCSEMS) with scheduled retrieval after seven days were also analyzed. Results: Eleven eligible studies were included in the review. Overall, 173 patients with CD were included in this study. Mean percentage of technical success was 95% (range, 80%-100%), short-term efficacy was 100% in all studies, and long-term efficacy was 56% (range, 25%-90%). In patients with a scheduled PCSEMS retrieval, the long-term efficacy was 76% (range, 59%-90%), the mean complication rate was 35% (range, 15%-57%), and the major complication rate was 11% (range, 0%-29%). Conclusions: Endoscopic stenting with scheduled PCSEMS retrieval may be considered a feasible second-line treatment for short CD strictures to postpone surgery. However, larger head-to-head prospective studies are needed to understand the role of stenting as an alternative or additional treatment to EBD in CD.

• Journal of the Korean Society of Radiology
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• v.6 no.2
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• pp.93-98
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• 2012

Micro-computed tomography (microCT) is an important tool for preclinical vascular imaging, with micron-level resolution. This non-destructive means of imaging allows for rapid collection of 2D and 3D reconstructions to visualize specimens prior to destructive analysis such as pathological analysis. Objectives. The aim of this study was to suggest a method for ex vivo, postmortem examination of stented arterial segments with microCT. And ex vivo evaluation of stents such as bare metal or drug eluting stents on in-stent restenosis (ISR) in rabbit model was performed. The bare metal stent (BMS) and drug eluting stent (DES, paclitaxel) were implanted in the left or right iliac arteries alternatively in eight New Zealand white rabbits. After 4 weeks of post-implantation, the part of iliac arteries surrounding the stent were removed carefully and processed for microCT. Prior to microCT analysis, a contrast medium was loaded to lumen of stents. All samples were subjected to an X-ray source operating at 50 kV and 200 ${\mu}A$ by using a 3D isotropic resolution. The region of interest was traced and measured by CTAN analytical software. Objects being exposed to radiation had different Hounsfield unit each other with values of approximately 1.2 at stent area, 0.12 ~ 0.17 at a contrast medium and 0 ~ 0.06 at outer area of stent. Based on above, further analyses were performed. As a result, the difference of lengths and volumes between expanded stents, which may relate to injury score in pathological analysis, was not different significantly. Moreover, ISR area of BMS was 1.6 times higher than that of DES, indicating that paclitaxel has inhibitory effect on cell proliferation and prevent infiltration of restenosis into lumen of stent. And ISR area of BMS was higher ($1.52{\pm}0.48mm^2$) than that of DES ($0.94{\pm}0.42mm^2$), indicating that paclitaxel has inhibitory effect on cell proliferation and prevent infiltration of restenosis into lumen of stent. Though it was not statistically significant, it showed that the extent of neointema of mid-region of stents was relatively higher than that of anterior and posterior region in parts of BMS as showing cross-sectional 2-D image. suggest that microCT can be utilized as an accessorial tool for pathological analysis.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.210-215
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• 2008

Background: Drug-eluting stents are contributing to the exponential growth of percutaneous coronary intervention, and even in the patients with left main coronary artery disease, owing to the decreased restenosis rate. Our study aimed at comparing the one-year results after coronary artery bypass grafting versus percutaneous coronary intervention with drug-eluting stents in patients with left main coronary artery disease. Material and Method: Those patients who underwent coronary bypass surgery or stenting at our hospital under the diagnosis of left main coronary artery disease were divided in two groups. The variables for comparison were the preoperative disease severity, the length of the hospital stay, the early mortality and the cumulative incidence of mortality, myocardial infarction and repeated revascularization. Result: There were 101 cases in the surgery group and 78 cases in the stent group. Age, gender, the risk factors, the left ventricular ejection fraction and the proportion of acute coronary syndrome showed no significant differences between the two groups. The surgery group showed a more severe condition according to the Euroscore, a greater incidence of urgency, a longer hospital stay and a greater incidence of multi-vessel disease. The early mortality and one-year cumulative mortality were not different between the groups. The Euroscore-matched comparison for the surgery group (41 patients) and the stent group (78 patients) showed no significant differences in the Euroscore, age, gender, risk factors and the proportion of acute coronary syndrome. The surgery group in the Euroscore-matched comparison showed more multi-vessel disease and a longer hospital stay. The surgery group showed lower early mortality and lower one-year cumulative mortality, but this was statistically insignificant (0% vs 2.6%, respectively, p=0.55; 0% vs 6.6%, respectively, p=0.30). The rates of repeated revascularization and major adverse events (death or myocardial infarct) were lower in the CABG group, but this was not statistically significant (13.3% vs 6.3%, respectively, p=0.48; 10.0% vs 0%, respectively, p=0.09). Conclusion: Percutaneous coronary intervention using drug-eluting stents in low-risk patients with left main coronary artery disease resulted in a shortened length of the hospital stay, as compared with that of the CABG group of patients. However, the patients who underwent percutaneous coronary intervention using drug-eluting stents showed a tendency for an increased rate of repeated revascularization and higher one-year cumulative mortality. Further studies with large populations and longer follow-up will be necessary to reaffirm our findings.

• Journal of Korean Neurosurgical Society
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• v.65 no.3
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• pp.422-429
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• 2022

Objective : Extracranial supra-aortic dissections (ESADs) with severe stenosis, occlusion and/or pseudoaneurysm presents potential risk of stroke. Endovascular stenting to reconstruct non acute phase ESADs (NAP-ESADs) is an alternative to anticoagulant or antiplatelet therapy. However, its feasibility, safety and efficacy of stenting in NAP-ESADs is unclear. This study aims to investigate the long-term outcomes of the feasibility, safety and efficacy of stenting in NAP-ESADs. Methods : Seventy-four patients with 91 NAP-ESAD vessels with severe stenosis, occlusion and/or pseudoaneurysm presents potential risk of stroke who underwent stent remodeling were enrolled into this respective study from December 2008 to March 2020. Technical success rate, complications, clinical and angiographic results were harvested and analyzed. Results : Success rate of stent deployment was 99% (90/91) with no procedural mortality or morbidity. Transient ischemic attack occurred in three patients during operation (4.1%, 3/74). Asymptomatic embolisms of distal intracranial vessels were found in two patients (2.7%, 2/74). One hundred and forty-two stents deployed at 85 carotid (135 stents) and six vertebral (seven stents) vessels. Six stent types (Wingspan, 28/135, 20.7%; Solitaire, 10/135, 7.4%; Neuroform, 8/135, 5.9%; LVIS, 2/135, 1.5%; Precise, 75/135, 55.6%; Acculink, 12/135, 8.9%) were deployed at carotid arterial dissection while two types (Wingspan, 5/7, 71.4%; Solitaire 2/7, 28.6%) at vertebral arterial dissection. Digital subtracted angiography (56%, 51/91), computational tomography angiography (41.8%, 38/91) and high resolution magnetic resonance imaging (2.2%, 2/91) were adopted for follow up, with a mean time of 17.2±15.4 months (5-77). All patient modified Rankin Scale scores showed no increase at discharge or follow-up. Angiographically, dissections in 86 vessels in 69 patients (94.5%, 86/91) were completely reconstructed with only minor remnant dissections in four vessels in four patients (4.4%, 4/91). Severe re-stenosis in the stented segment required re-stenting in one patient (1.1%, 1/91). Conclusion : Stent remodeling technique provides feasible, safe and efficacious treatment of ESADs patients with severe stenosis, occlusion and/or pseudoaneurysm.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1175-1183
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• 2020

Purpose To evaluate the technical feasibility and clinical efficacy of percutaneous transgastric stent placement after the failure of treatment attempt with the transoral approach in malignant gastroduodenal obstruction patients. Materials and Methods From October 2008 to April 2016, nine patients (M:F = 4:5; mean age = 66 years) with malignant gastroduodenal obstruction underwent stent placement via a gastrostomy tract, which was attributed to the failure of the transoral approach. The primary etiologies of the obstruction were pancreatic (n = 5), gastric (n = 2), and metastatic (n = 2) cancers. Through percutaneous gastrostomy, dual stents (inner bare metal and outer polytetrafluoroethylene-covered) were deployed at the obstruction site. The technical and clinical success rates, as well as complications were evaluated during the follow-up period. Results Stents were successfully inserted in eight patients (88%). We failed to insert stent in one patient due to the presence of a tight obstruction. After stent placement, symptoms improved in seven patients. Gastrostomy tube was removed 9 to 20 days (mean = 12 days) after the stent insertion. During the mean follow-up of 136 days (range, 3-387 days), one patient developed a recurrent symptom due to tumor overgrowth. However, there were no other major complications associated with the procedure. Conclusion Percutaneous transgastric stent placement appeared to be technically feasible and clinically effective in patients who underwent a failed transoral approach.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.197-211
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• 2023

Purpose To evaluate the circuit patency after nitinol bare-metal stent (BMS) placement according to the type of access and location of the stent in dysfunctional hemodialysis access. Materials and Methods Between January 2017 and December 2019, 159 patients (mean age, 64.1 ± 13.2 years) underwent nitinol BMS placement for dysfunctional access. The location of stents was as follows: 18 brachiocephalic vein, 51 cephalic arch, 40 upper arm vein, 10 juxta-anastomotic vein, 7 arteriovenous (AV) anastomosis, and 33 graft-vein (GV) anastomosis. Circuit patency was evaluated by the Kaplan-Meier method, and cox regression model. Results A total of 159 stents were successfully deployed in 103 AV fistula (AVF) and 56 AV graft (AVG). AVG showed lower primary and secondary patency at 12-months compared with AVF (primary patency; 25.0% vs. 44.7%; p = 0.005, secondary patency; 76.8% vs. 92.2%; p = 0.014). Cox regression model demonstrated poorer primary patency at 12 months after stenting in the cephalic arch and GV anastomosis compared with the other sites. Conclusion AVF showed better primary and secondary circuit patency at 12 months following the placement of BMS compared with AVG. Stents in the cephalic arch and GV anastomosis were associated with poorer primary patency at 12 months compared to those in other locations.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.10
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• pp.121-125
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• 2006

In this paper, results are presented by nonlinear finite element simulations in order to analy the interactions between the stent and artery or plaque. Maximum of von Mises stress was calculated in the contacting areas between the stent and the artery. The simulated results show that the distal end of stent, which tilts after expansion, may injure the artery wall. In conclusion, this study may help designing new stents.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.557-558
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• 2006

• 대한임상약리학회:학술대회논문집
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• 2005.12a
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• pp.6-6
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• 2005